USRE46465E1 - Wafer transfer apparatus and substrate transfer apparatus - Google Patents

Abstract

A wafer transfer apparatus is provided. In a minimum transformed state where a robot arm is transformed such that a distance defined from a pivot axis to an arm portion, which is farthest in a radial direction relative to the pivot axis, is minimum, a minimum rotation radius R, is set to exceed ½ of a length B in the forward and backward directions of an interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value obtained by subtracting a distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<R≦B−L0).

Description

The present Reissue Application is a Divisional Reissue of Reissue application Ser. No. 13/750,625, which is a Reissue Application of U.S. Pat. No. 7,874,782, issued Jan. 25, 2011, Ser. No. 11/879,509.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon the prior Japanese Patent Application No. 2006-198771 filed on Jul. 20, 2006, the entire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wafer transfer apparatus for use in semiconductor processing equipment. The present invention also relates to a substrate transfer apparatus for transferring a substrate in an interface space, which is maintained in a predetermined atmosphere, of a substrate processing equipment.

2. Description of the Related Art

FIG. 13 is a section showing asemiconductor processing equipment1 of the related art, which is partly cut away. Thesemiconductor processing equipment1 is configured to include awafer processing apparatus2 and awafer transfer apparatus3. The wafer transfer apparatus is an equipment front end module (EFEM).Spaces9,10 in thesemiconductor processing equipment1 are filled with a predetermined atmospheric gas, respectively. Specifically, thewafer processing apparatus2 includes aprocessing space10 which is filled with a predetermined atmospheric gas. Similarly, thewafer transfer apparatus3 includes aninterface space9 which is filled with a predetermined atmospheric gas.

Semiconductor wafers4, which are contained in each front opening unified pod (FOUP)5 serving as a substrate container, are each carried into thesemiconductor processing equipment1. Thewafer transfer apparatus3 includes an interfacespace forming portion11,FOUP openers6, and awafer carrying robot7. Abox11 defines theinterface space9. Theinterface space9 is maintained in a cleaned state due to a dust collecting apparatus, such as a fan filter unit, which is fixed to the box11 (i.e., interface space forming portion). EachFOUP opener6 is adapted to open and close doors respectively provided in theFOUP5 and the interfacespace forming portion11. EachFOUP opener6 can switch a state in which an internal space of eachFOUP5 and theinterface space9 are in communication with each other and a state in which they are closed to each other, by opening and closing each door. Awafer carrying robot7 is contained in theinterface space9 and is adapted to carry eachwafer4 between eachFOUP5 and thewafer processing apparatus2.

Thewafer carrying robot7 takes out eachunprocessed wafer4 from eachFOUP5 in a state wherein the FOUP5 is held by thewafer transfer apparatus3 and penetration of the outside air into theinterface space9 is prevented. Then, therobot7 carries theunprocessed wafer4 taken from the FOUP5, passes through theinterface space9, and positions thewafer4 in theprocessing space10 of thewafer processing apparatus2. In addition, thewafer carrying robot7 takes out each processedwafer4 from theprocessing space10 of thewafer processing apparatus2. Thereafter, thewafer carrying robot7 carries the processedwafer4 taken out from theprocessing space10, passes through theinterface space9, and places thewafer4 again in the internal space of the FOUP5. By transferring eachwafer4 into thewafer processing apparatus2 by using eachFOUP5 and thewafer transfer apparatus3 in this manner, attachment of dust floating in the atmosphere to thewafer4 to be processed can be prevented. For example, such a technique is disclosed in JP No. 2003-45933 A.

FIG. 14 is a plan view of a semiconductor processing equipment1A of a first related art, which is partly cut away. Arobot arm14 of thewafer carrying robot7 of the first related art includes afirst link member15a which is connected with abase18 and can be pivoted about a pivot axis A0 set at thebase18, asecond link member15b which is connected with thefirst link member15a and can be angularly displaced about a first joint axis A1 set at thefirst link member15a, and athird link member15c which is connected with thesecond link member15b and can be angularly displaced about a second joint axis A2 set at thesecond link member15b. Thethird link member15c has arobot hand12 provided at its distal end.

Thewafer carrying robot7 is set such that aminimum rotation region17, which is required for therobot7 to perform one rotation about thebase18 in a state wherein eachlink member15a to15c is angularly displaced relative to one another to make the smallest form of therobot7, can be contained in theinterface space9. In other words, a minimum rotation radius R of the robot is set smaller than a half (½) of a length B (FIG. 15) in forward and backward directions of theinterface space9. In addition, a distance L11 between the pivot axis A0 and the first joint axis A1 and a distance L12 between the first joint axis A1 and the second joint axis A2 are set to be the same.

In order to enable thewafer transfer apparatus3 to perform attaching and detaching operations of eachFOUP5 relative to thewafer transfer apparatus3 and a transferring operation of eachwafer4 to and from eachFOUP5 held by thewafer transfer apparatus3, at the same time, there is a case where three or fourFOUP openers6 are provided in the system. In such a case, thewafer carrying robot7 of the first related art as described above can not reach, in some cases, the FOUP5 that is farthest from the base15, by using itshand12. However, if attempting to extend the length of each link member in order to enlarge a movable region of therobot7, therobot arm14 may interfere with the interfacespace forming portion11 and may be advanced into a robot invasion restricted region.

FIG. 15 is a plan view showing a semiconductor processing equipment1B of a second related art, which is partly cut away. As shown inFIG. 15, in the second related art, in order to make it possible to transferwafers4 of all of theFOUPs5, thewafer carrying robot7 includes a robotmain body13 having arobot arm14 and a runningmeans12 which is adapted to drive the robotmain body13 to run in directions Y parallel to the row of theFOUPs5.

In the second related art, the running means12 for driving the robotmain body13 to run is located in theinterface space9. The runningmeans12 can be achieved by employing a direct acting mechanism. It is difficult, however, to seal the direct acting mechanism against dust to be generated in a driving portion, as compared with the case of a rotation driving mechanism. Therefore, due to dust to be generated by the running means, cleanliness in theinterface space9 may tend to be degraded.

In the case of driving the robotmain body13 to run at a high speed, since the robotmain body13 is of a large size, power to be spent for the running operation of the robotmain body13 should be increased, with respect to therunning means12. In addition, therunning means12 should also be of a large size in order to support the robotmain body13, thus making it difficult to downsize therobot7 and reduce the weight thereof. Because therunning means12 is of a large size, it is difficult to exchange the runningmeans12 in the case of occurrence of malfunctioning in therunning means12. In addition, the provision of such a running means12 leads to further increase of the production cost.

Increase of the number of the link members of therobot arm14 in order to enlarge the movable region of thewafer carrying robot7 can make therunning means12 as disclosed in the second related art be unnecessary. However, in the case of increasing the number of the link members of therobot arm14, the robot structure should be complicated so much. Additionally, the increase of the link members increases in turn redundancy of the robot, as such control of therobot arm14 may tend to be difficult. For example, in regard to the wafer transfer, a teaching operation for teaching transformed states of the robot arm may be further complicated.

Such problems may occur in other apparatuses than the wafer transfer apparatus. Specifically, in the case of substrate transfer apparatuses each provided with a substrate carrying robot for carrying each substrate in the interface space which is maintained in a predetermined atmosphere, the same problems as those describe above may occur.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a wafer transfer apparatus having a wafer transfer robot which can suppress scattering of dust and prevent occurrence of interference in the interior of the wafer transfer apparatus, and has a simple structure and can be readily controlled.

Another object of the present invention is to provide a substrate transfer apparatus having a substrate transfer robot which can suppress scattering of dust and prevent occurrence of interference in the interior of the substrate transfer apparatus, and has a simple structure and can be readily controlled.

The present invention is a wafer transfer apparatus for transferring a semiconductor wafer which is carried while being contained in a substrate container, relative to a wafer processing apparatus for semiconductor processing, comprising: an interface space forming portion defining an interface space which is to be filled with a preconditioned atmospheric gas, the interface space forming portion having a front wall and a rear wall which are arranged at a predetermined interval in forward and backward directions, the front wall having a front opening formed therein, and the rear wall having a rear opening formed therein; a FOUP opener configured to open and close the substrate container located adjacent to the interface space and the front opening of the interface space forming portion; and a wafer carrying robot located in the interface space and configured to carry the semiconductor wafer between the front opening and the rear opening. The wafer carrying robot includes: a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set; a robot arm having a proximal end and a distal end, the robot arm including a plurality of link members connected with one another in succession in a direction from the proximal end to the distal end, the proximal end being connected with the base, the distal end being provided with a robot hand for holding the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and a drive unit configured to drive each of the link members of the robot arm so that the link members are angularly displaced, individually, about each corresponding axis. In a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<R≦B−L0).

According to this invention the substrate container is located while being adjacent to the front opening of the interface space forming portion. In this state, the FOUP opener opens the substrate container together with the front opening so as to make the internal space of the substrate container and the interface space be in communication with each other. The wafer carrying robot takes out an unprocessed wafer from the substrate container, carries the unprocessed wafer into the interface space from the front opening, passes through the interface space, and carries the wafer into the wafer processing apparatus through the rear opening. Alternatively, the wafer carrying robot takes out a processed wafer which has been processed in the wafer processing apparatus, carries it into the interface space from the rear opening, passes through the interface space, and carries the wafer into the substrate container through the front opening.

In the interface space, the atmospheric gas is controlled. Thus, when carrying the unprocessed wafer into the wafer processing apparatus from the substrate container, or when carrying the processed wafer into the substrate container from the wafer processing apparatus, attachment of dust floating in the atmosphere to the wafer can be prevented, thereby enhancing the yield of the wafer to be processed.

In the present invention, the minimum rotation radius R of the robot arm can be increased, as compared to the first and second related arts described above, by setting the minimum rotation radius R of the robot arm at a value greater than ½ of the length B in the forward and backward directions of the interface space. In addition, with the minimum rotation radius R of the robot arm set to be equal to or less than the subtracted value (B−L0), a gap can be securely provided between the robot arm in its minimum transformed state and the front wall, thus preventing interference of the robot arm with the front wall. In this manner, a robot hand which is a distal end of the robot arm can be located on both sides in the left and right directions, orthogonally to both of the forward and backward directions and the pivot axial direction extending along the pivot axis, with respect to a reference line defined to include the pivot axis and extend in the forward and backward directions. By driving the robot arm to be operated in an operational range excluding an interferential operational range in which the robot arm would interfere with the rear wall, interference with the rear wall can also be prevented. Namely, with the restriction of the angularly displacing operational range of the robot arm to be less than 360 degrees, for example, about 180 degrees, interference of the robot arm with the rear wall can be prevented.

Thus, even though the length B in the forward and backward directions of the interface space is significantly small, the length of each link member of the robot arm can be increased, while preventing the interference of the robot arm with the front wall, so as to enlarge the operational range of the robot arm. In particular, the operational range of the robot arm can be enlarged with respect to the left and right directions orthogonal to both the forward and backward directions and the pivot axial direction. For example, the distance L0 in the forward and backward directions from the rear wall to the pivot axis A0 is set to be less than ⅕ of the length B in the forward and backward directions of the interface space (i.e., L0<B/5).

By increasing the link length of each link member of the robot arm, the operational range of the robot arm can be increased with respect to the left and right directions. Thus, as compared with the second related art, there is no need for a running means for driving the robot to run in the left and right directions, and a direct acting mechanism can be eliminated. Accordingly, dust to be generated by such a direct acting mechanism can be avoided, as such degradation of the cleanliness in the interface space can be prevented. In addition, the elimination of the running means leads to downsizing and weight reduction of the robot.

Also, by increasing the link length of each link member of the robot arm, it becomes possible to have the robot hand reach a predetermined position in a wider range. Additionally, necessity for increasing the number of the link members can be avoided, thus simplifying the robot structure. Furthermore, the redundancy of the robot can be reduced, and the control and teaching concerning transformed states for the robot arm can be simplified, thereby reducing possibility that the robot arm would collide with the interface space forming portion.

As described above, in this invention, scattering of dust can be suppressed due to elimination of the running means, as well as interference in the wafer transfer apparatus can be avoided. Therefore, a wafer transfer apparatus including a wafer carrying robot, which can achieve more simplified structure and control, can be provided.

Preferably, the minimum rotation radius R is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., R≦B−L0−E).

According to this invention, by setting the minimum rotation radius R to be equal to or less than the allowable length (B−L0−E), even in the case where the robot arm approaches nearest relative to the front wall, entering of any portion of the robot arm into a movable region of the FOUP opener can be prevented. Therefore, interference of the robot arm with the FOUP opener can be prevented, regardless of the movable region or state of the FOUP opener. Thereby, defective operations of the wafer transfer apparatus can be eliminated.

Preferably, the robot arm includes: a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis; a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; and a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes the robot hand at an other end of the third link member for holding the wafer. A first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E).

According to this invention, the first link distance L1 is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E). Consequently, even in the case where the first link member approaches nearest relative to the front wall, entering of any portion of the first link member into a movable region of the FOUP opener can be prevented. Thus, the other end of the first link member can be moved on both sides in the left and right directions relative to the pivot axis while preventing its interference with the front wall. By increasing the first link distance L1, as large as possible, provided that it is set to be equal to or less than the allowable length (B−L0−E), interference of the first link member with the front wall as well as with the FOUP opener can be prevented, and the other end of the first link member can be moved into a significantly far position in both of the left and right directions with respect to the pivot axis, thereby to enlarge the operational range of the first link member. Namely, interference of the first link member with the front wall as well as with the FOUP opener can be prevented, while increasing the link length of the first link member. Additionally, due to restriction of the angularly displacing operational range of the robot arm to be less than 360 degrees, for example, about 180 degrees, interference of the first link member with the rear wall can also be prevented. Due to the increase of the length of the first link member, the second and third link members can be located in farther positions from the pivot axis in the left and right directions, thus enlarging the movable region of the robot in the left and right directions.

Preferably, a first axis-to-axis distance L11 from the pivot axis to the first joint axis and a second axis-to-axis distance L12 from the first joint axis to the second joint axis are set to be equal to each other. A second link distance L2 defined as a distance from the second joint axis to an end of the second link member, which is farthest in a direction toward the first joint axis relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

According to this invention, in a state where the second link member is overlapped with the first link member with respect to the pivot axial direction such that the pivot axis is coincident with the second joint axis, the distance from the second joint axis to the end portion of the second link member, which is the farthest from the pivot axis, is set to be equal to or less than the allowable length (B−L0−E). Accordingly, in the state wherein the pivot axis is coincident with the second joint axis, entering of any portion of the second link member into the movable region of the FOUP opener can be prevented. Additionally, by increasing the second link distance L2, as large as possible, provided that it is set to be equal to or less than the allowable length (B−L0−E), interference of the second link member with the front wall as well as with the FOUP opener can be prevented, and the other end of the second link member can be moved into a significantly far position in both of the left and right directions with respect to the pivot axis, thereby to enlarge the operational range of the second link member. Namely, by driving the robot arm to take its minimum transformed state by overlapping the first link member with the second link member, interference of the second link member with the front wall as well as with the FOUP opener can be prevented, while increasing the link length of the second link member. This increase of the length of the second link member enables the third link member to be located in a position farther from the pivot axis in the left and right directions, thereby enlarging the movable region of the robot in the left and right directions.

By setting the first axis-to-axis distance L11 and the second axis-to-axis distance L12 to be the same, and by setting an angularly displacing amount of the first link member about the pivot axis to be twice the angularly displacing amount of the second link member about the first angular displacement axis, the other end of the second link member can be moved in parallel to the left and right directions, thus facilitating control of the arm body. It should be noted that the term “the same” is intended to imply substantially the same state, as such it includes the same state and substantially the same state.

Preferably, a third link distance L3 defined as a distance from the second joint axis to an end of the third link member or a portion of the wafer, which is farthest in a radial direction relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

According to this invention, in a state wherein the first to third link members are overlapped such that the pivot axis is coincident with the second joint axis, the distance from the second joint axis to the end portion of the third link member, which is the farthest from the pivot axis, is less than the allowable length (B−L0−E). Accordingly, in the state where the pivot axis is coincident with the second pivot axis, entering of any portion of the third link member or any portion of the wafer held by the third link member into the movable region of the FOUP opener can be prevented. In addition, by increasing the third link distance L3, as large as possible, provided that it is set to be equal to or less than the allowable length (B−L0−E), interference of the third link member with the front wall as well as with the FOUP opener can be prevented, and the other end of the third link member can be moved into a significantly far position in both of the left and right directions with respect to the pivot axis, thereby to enlarge the operational range of the third link member. Namely, by operating the robot arm to take its minimum transformed state by driving the first to third link members to be overlapped with one another, interference of the third link member with the front wall as well as with the FOUP opener can be prevented, while increasing the link length of the third link member. Due to such increase of the length of the third link member, the wafer held by the third link member can be located in a farther position from the pivot axis in the left and right directions, thereby to extend the movable region of the robot in the left and right directions.

Preferably, the first link distance L1, the second link distance L2 and the third link distance L3 are respectively set to be equal to the allowable length (B−L0−E).

According to this invention, the first to third link distances L1 to L3 are each set to be the same as the allowable length (B−L0−E). Consequently, when the robot arm is in the minimum transformed state, contact of each link member with the front wall as well as with the FOUP opener can be prevented. The term “the same” is intended to imply substantially the same state, as such it includes the same state and substantially the same state. Since each link member is set to be as large as possible while preventing interference, the operational range of the robot arm with respect to the left and right directions can be increased. Thus, even in the case where the front opening and the rear opening are formed away from each other in the left and right directions, this robot arm can perform both carrying in and carrying out operations for each wafer. Namely, in the case where the robot arm takes its minimum transformed state, contact of each link member with the front wall as well as with the FOUP opener can be prevented. In addition, the length of each link member can be increased as large as possible, the operational range of the robot arm can be increased so much. Therefore, even in the case where the front opening and the rear opening are provided in positions spaced away relative to each other in the forward and backward directions, the robot arm can perform the carrying in and carrying out operations for each wafer.

Preferably, the front opening includes four openings which are formed in the interface space forming portion, the four openings being arranged in left and right directions orthogonal to both the forward and backward directions and a direction of the pivot axis. The FOUP opener includes four openers which are provided in order to open and close the four openings, respectively.

According to this invention, even in the case where the length B in the forward and backward directions of the interface space is relatively small as described above, the operational range in the left and right directions of the robot arm can be significantly increased. Thus, even in the case where the four FOUP openers are provided, carrying in and carrying out operations for each wafer between the substrate container attached to each FOUP opener and the wafer processing apparatus can be secured, without providing any additional running means for the robot, and without increasing the number of link members of the robot arm. Since the four FOUP openers are provided, the carrying, attachment and detachment operations of each substrate container relative to the wafer transfer apparatus and the transfer operation of each wafer contained in the substrate container held by the wafer transfer apparatus can be carried out, in parallel, thereby enhancing the working efficiency.

The present invention is a substrate transfer apparatus for transferring a substrate, in an interface space filled with a preconditioned atmospheric gas, relative to a substrate processing apparatus for processing the substrate, comprising:

an interface space forming portion defining the interface space, the interface space forming portion having a front wall and a rear wall which are arranged in predetermined forward and backward directions at an interval, the front wall having a first transfer port formed therein, and the rear wall having a second transfer port formed therein; an opening and closing unit configured to open and close the first transfer port of the interface, space forming portion; and a substrate carrying robot located in the interface space and configured to carry the substrate between the first transfer port and the second transfer port. The substrate carrying robot includes: a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set; a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis; a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes a robot hand at an other end thereof for holding the substrate; and a drive unit configured to drive each of the link members so that the link members are angularly displaced, individually, about each corresponding axis. The pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions. A first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<L1≦B−L0).

According to this invention, the minimum rotation radius R of the robot arm can be increased, as compared with the first and second related arts, by setting the minimum rotation radius R of the robot arm to exceed ½ of the length B in the forward and backward directions of the ready arm. In addition, by setting the minimum rotation radius R of the robot arm to be equal to or less than the aforementioned subtracted value (B−L0), a gap can be securely provided between the robot arm in its minimum transformed state and the front wall, thus preventing interference of the robot arm with the front wall. With the restriction of the angularly displacing operational range of the robot arm to be less than 360 degrees, for example, about 180 degrees, interference of the robot arm with the rear wall can also be prevented.

Consequently, even in the case where the length B in the forward and backward directions of the interface space is relatively small, the link length of each link member of the robot arm can be increased, while preventing interference between the robot arm and the front wall. Accordingly, the operational range of the robot arm can be increased. In particular, the operational range of the robot arm can be increased, with respect to the left and right directions orthogonal to both of the forward and backward directions and the pivot axial direction. Thus, the robot arm can be adequately operated without requiring any additional running means and/or unduely increasing the number of the link members.

According to the substrate transfer apparatus of the present invention, there is no need for a running means for driving the robot to run in the left and right directions, and dust to be generated by such a running means can be avoided, thereby preventing degradation of the cleanliness in the interface space. In addition, the number of the link members required for the robot arm can be reduced, as such simplifying the robot structure. Moreover, the redundancy of the robot can be decreased, thereby to reduce the possibility that the robot arm would collide with the interface space forming portion.

As stated above, according to the present invention, scattering of dust can be suppressed due to the elimination of the running means, and occurrence of interference in the substrate transfer apparatus can be avoided due to the control of increase of the link members. Therefore, the substrate transfer apparatus comprising the substrate transfer robot which can simplify the structure and control can be provided. It should be appreciated that the substrate transfer apparatus can be applied to other substrates than the semiconductor wafer, and that these substrates may include those to be processed in a preset controlled space, for example, glass substrates or the like.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a plan view showing a part ofsemiconductor processing equipment20 comprising awafer transfer apparatus23 which is a first embodiment of the present invention;

FIG. 2 is a section showing thesemiconductor processing equipment20, which is partly cut away;

FIG. 3 is a plan view showing a wafer transfer apparatus, which is simplified, for explaining a length of eachlink member41a to41c;

FIG. 4 is a diagram showing a carrying operation, which is simplified, for carrying awafer24 contained in afirst FOUP25a to analigner56;

FIG. 5 is a diagram showing a carrying operation, which is simplified, for carrying thewafer24 supported by thealigner56 to aprocessing space30;

FIG. 6 is a diagram showing a carrying operation, which is simplified, for carrying thewafer24 located in theprocessing space30 to thefirst FOUP25a;

FIG. 7 is a diagram showing a state in which thewafer24 is located in its receiving and transferring positions of the embodiment according to the present invention;

FIG. 8 is a plan view showing the wafer transfer apparatus in the case that there are three FOUP openers;

FIG. 9 is a plan view showing the wafer transfer apparatus in the case that there are two FOUP openers;

FIG. 10 is a plan view showing awafer transfer apparatus23A, which is a second embodiment of the present invention and is somewhat simplified;

FIG. 11 is a plan view showing awafer transfer apparatus23B, which is a third embodiment of the present invention and is somewhat simplified;

FIG. 12 is a plan view showing asemiconductor processing apparatus20C which is a fourth embodiment of the present invention;

FIG. 13 is a section showing asemiconductor processing equipment1 of the related art, which is partly cut away;

FIG. 14 is a plan view showing a semiconductor processing equipment1A of a first related art, which is partly cut away;

FIG. 15 is a plan view showing a semiconductor processing equipment1B of a second related art, which is partly cut away.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIGS. 1 and 2, thesemiconductor processing equipment20 according to the first embodiment of the present invention provides a predetermined process to eachsemiconductor wafer24 which is a substrate to be processed. For example, as the process to be provided to thesemiconductor wafer24, various processes including heating, impurity doping, film forming, lithography, washing or flattening may be included. In addition, thesemiconductor processing equipment20 may perform other substrate processes than those described above.

Thesemiconductor processing equipment20 performs the aforementioned processes in aprocessing space30 filled with an atmospheric gas having adequate cleanliness.Wafers24 are carried into thesemiconductor processing equipment20 while being contained in large numbers in a-substrate container referred to as a front opening unified pod (FOUP)25. Each FOUP25 is intended to serve as a mini-environmental substrate container configured to provide a clean environment for the locally cleaning technique.

Each FOUP25 is configured to include a FOUPmain body60 which is a container main body in which thewafers24 are contained, and a FOUP-side door61 as a container-side door which can be attached to and detached from the FOUPmain body60. The FOUPmain body60 is formed into a generally box-like shape which opens in one direction, and in which a FOUPinternal space34 is defined as a space for containing the wafers. Due to attachment of the FOUP-side door61 to the FOUPmain body60, the FOUPinternal space34 is closed air-tightly against anexternal space33, as such invasion of contaminant, such as dust particles, from theexternal space33 into the FOUPinternal space34 can be prevented. Contrary, due to removal of the FOUP-side door61 from the FOUPmain body60, thewafer24 can be contained in the FOUPinternal space34, as well as thewafers24 contained in the FOUPinternal space34 can be taken out therefrom. Each FOUP25 contains a plurality ofwafers24 therein in a stacked state in upward and downward directions Z. Eachwafer24 contained in the FOUP25 is arranged at an equal interval in the upward and downward directions Z, with one face in the thickness direction extending horizontally.

Thesemiconductor processing equipment20 is configured to include awafer processing apparatus22 and awafer transfer apparatus23. Thesemiconductor processing equipment20 is prescribed, for example, in the SEMI (Semiconductor Equipment and Materials International) standard. In this case, for example, each FOUP25 and aFOUP opener26 adapted to open and close the FOUP25 follow the specifications, including E47.1, E15.1, E57, E62, E63, E84, of the SEMI standard. It should be noted that even though the construction of the semiconductor processing equipment does not fall within the SEMI standard, such construction may also be included in this embodiment.

Thewafer processing apparatus22 provides the predetermined process described above to eachwafer24 in theprocessing space30. In addition to a processing apparatus main body adapted to provide a process to eachwafer24, thewafer processing apparatus22 includes a processing space forming portion defining theprocessing space30, a carrier adapted to carry eachwafer24 in theprocessing space30, and a controller adapted to control the atmospheric gas filled in theprocessing space30. The controller can be achieved by a fan filter unit or the like.

Thewafer transfer apparatus23 is configured to take out eachunprocessed wafer24 from each FOUP25 and supply it into thewafer processing apparatus22, as well as configured to take out each processedwafer24 from thewafer processing apparatus22 and place it in each FOUP25. Thewafer transfer apparatus23 is an equipment front end module (EFEM). Thewafer transfer apparatus23 serves as an interface, which is adapted to transfer eachwafer24 between each FOUP25 and thewafer processing apparatus22. In this case, thewafer24 passes through aninterface space29 filled with a predetermined atmospheric gas and having high cleanliness, during its movement between each FOUPinternal space34 and theprocessing space30 of thewafer processing apparatus22.

Theinterface space29 is a closed space to which contamination control is provided and in which the number of floating micro-particles in the air is controlled to be less than a limited level of cleanliness. In addition, theinterface space29 is a space in which environmental conditions, such as temperature, humidity and pressure, are also controlled as needed. In this embodiment, the cleanliness ofprocessing space30 andinterface space29 is maintained such that it does not have negative impact on the process for eachwafer24. For example, as the cleanliness, the CLASS1 prescribed in the international organization for standardization (ISO) is employed.

Thewafer transfer apparatus23 includes an interfacespace forming portion28 defining theinterface space29, thewafer carrying robot27 which is located in theinterface space29 and capable of carrying each wafer,FOUP openers26 which serve as opening and closing apparatuses each adapted to open and close each corresponding FOUP25, and aninterface space controller100 adapted to control an atmospheric gas filled in theinterface space29. In this embodiment, thewafer transfer apparatus23 further includes analigner56 adapted to align a direction of eachwafer24 held in a predetermined position.

The interfacespace forming portion28 surrounds theinterface space29 to prevent the outside air from entering theinterface space29 from theexternal space33. In the interfacespace forming portion28, carrier elements required for carrying eachwafer24 are fixed respectively. In this embodiment, fourFOUP openers26a,26b,26c,26d, onewafer transfer robot27, and onealigner56 are fixed in the interfacespace forming portion28, respectively.

The interfacespace forming portion28 is formed into a rectangular parallelepiped box-like shape, so as to form a rectangularparallelepiped interface space29. The interfacespace forming portion28 includes afront wall110 and arear wall111 which are arranged to provide a predetermined interval therebetween in forward and backward directions X. Thefront wall110 serves as a partition for separating theinterface space29 from theexternal space33 existing in a position on the side in the forward direction X1 relative to theinterface space29. Therear wall111 serves as a partition for separating theinterface space29 from theprocessing space30. Accordingly, the readspace29 is located on the side in the backward direction X2 relative to theexternal space33 and is defined on the side in the forward direction X1 relative to theprocessing space30.

The interfacespace forming portion28 includes twoside walls112,113 which are arranged to provide an interval in the left and right directions Y. In addition, the interfacespace forming portion28 includes aceiling wall114 and abottom wall115 which are arranged to define an interval in the upward and downward directions Z. Thesewalls110 to115 of the interfacespace forming portion28 are each formed into a plate-like shape.

In this embodiment, the forward and backward directions X and the left and right directions Y are predefined directions, respectively. The forward and backward directions X and the left and right directions Y are orthogonal to the upward and downward directions Z, respectively, and extend horizontally to be orthogonal to each other. The backward direction X2 of the forward and backward directions X is a direction in which eachwafer24 contained in each FOUP25 is carried into theprocessing space30. The forward direction X1 of the forward and backward directions X is a direction in which eachwafer24 contained in theprocessing space30 is carried back into each corresponding FOUP25.

Thefirst side wall112 connects one ends together in the left and right directions of thefront wall110 andrear wall111. Thesecond side wall113 connects the other ends together in the left and right directions of thefront wall110 andrear wall111. Theceiling wall114 connects top ends of thefront wall110,rear wall111,first side wall112 andsecond side wall113, respectively. Thebottom wall115 connects bottom ends of thefront wall110,rear wall111,first side wall112 andsecond side wall113, respectively.

Theinterface space29 is closed in the forward and backward directions X by thefront wall110 and therear wall111. In addition, theinterface space29 is closed in the left and right directions Y by thefirst side wall112 and thesecond side wall113. Furthermore, theinterface space29 is closed in the upward and downward directions Z by theceiling wall114 and thebottom wall115. In this manner, theinterface space29 is defined. The interfacespace forming portion28 has a sectional shape vertical to the upward and downward directions Z such that the left and right directions Y corresponds to its longitudinal direction and the forward and backward directions X corresponds to its width direction, so as to be defined as a square frame. Accordingly, theinterface space29 defines an oblong space that is longer in the left and right directions Y than in the forward and backward directions X.

In thefront wall110,front openings120 are formed, each extending through the wall in the forward and backward directions X, i.e., in the thickness direction. Eachfront opening120 is formed to enable eachwafer24 to pass therethrough. Specifically, due to thewafer carrying robot27, eachwafer24 is moved to pass through each correspondingfront opening120, and carried in the backward direction X2 relative to thefront wall110, thus inserted into theinterface space29 from theexternal space33. Alternatively, due to thewafer carrying robot27, eachwafer24 is moved to pass through each correspondingfront opening120, and carried in the forward direction X1 relative to thefront wall110, thus discharged into theexternal space33 from theinterface space29. In this embodiment, fourfront openings120 are provided such that the respectivefront openings120 are arranged in the left and right directions Y.

In therear wall111,rear openings121 are formed, each extending through the wall in the forward and backward directions X, i.e., in the thickness direction. Eachrear opening121 is formed to enable eachwafer24 to pass therethrough. Again, due to thewafer carrying robot27, eachwafer24 is moved to pass through each correspondingrear opening121, and carried in the backward direction X2 relative to therear wall111, thus inserted into theprocessing space30 from theinterface space29. Alternatively, due to thewafer carrying robot27, eachwafer24 is moved to pass through each correspondingrear opening121, and carried in the forward direction X1 relative to therear wall111, thus inserted into theinterface space29 from theprocessing space30. In this embodiment, tworear openings121 are provided such that the respectiverear openings121 are arranged in the left and right directions Y

TheFOUP openers26a to26d are each configured to include afront face plate101, an opener-side door65, aFOUP supporting portion31, and a door opening andclosing mechanism109. TheFOUP openers26a to26d are arranged at an equal interval in the left and right directions Y. TheFOUP openers26a to26d are located on the side in the forward direction X1 relative to the interfacespace forming portion28. EachFOUP opener26a to26d also serves as a substrate container setting table for setting each corresponding FOUP, i.e., the substrate container. Accordingly, eachFOUP opener26a to26d is adapted to work as the substrate container setting table for supporting at least each corresponding FOUP.

Eachfront face plate101 constitutes a part of thefront wall110 of the interfacespace forming portion28. Thefront face plate101 of eachFOUP opener26a to26d is a plate-like or frame-like member defining eachfront opening120 described above therein, and constitutes thefront wall110 while being fixed to the remainder of thefront wall110. To thefront opening120 defined in eachfront face plate101, the FOUP-side door61 is provided such that it can pass therethrough in the forward and backward directions X.

Each opener-side door65 is adapted to open and close each correspondingfront opening120. EachFOUP supporting portion31 is located in theexternal space33 on the side in the forward direction X1 relative to theinterface space29 and adapted to support each FOUP25 from below. Each FOUP25 is formed such that it can be located in an attaching position, which is set by each correspondingFOUP supporting portion31, while being supported by theFOUP supporting portion31. Hereinafter, the FOUPs supported correspondingly to the first tofourth FOUP openers26a to26d will be referred to as first tofourth FOUPs25a to25d, respectively. However, when it is not necessary to distinguish them as the first tofourth FOUPs25a to25d, they will be merely referred to as the FOUP(s)25 or each FOUP25.

In a state wherein the FOUP25 is located in an attaching position, theopening60a of the FOUPmain body60 is in contact with all the circumference of the opening portion101a of thefront face plate101. In the state located in the attaching position, theFOUP door61 is opposed from theexternal space33 to the opener-side door65 closing thefront opening120.

Each door opening andclosing mechanism109 is adapted to open and close each corresponding opener-side door65 and FOUP-side door61 while each corresponding FOUP25 is located in the attaching position. When the door opening andclosing mechanism109 holds directly or indirectly the opener-side door65 and the FOUP-side door61, moves them from eachopening60a,101a downward and in the backward direction X2, and then moves them to a release position set in theinterface space29, the FOUPinternal space34 and theinterface space29 are in communication with each other. Contrary, when the door opening andclosing mechanism109 attaches the opener-side door65 and the FOUP-side door61 to theopenings60a,101a, respectively, the communication between the FOUPinternal space34 and theinterface space29 is shut off.

In the state wherein the FOUP25 is located in the attaching position, theopening60a of the FOUPmain body60 and the opening101a of thefront face plate101 are in contact with each other over all of their peripheries. Accordingly, in the state wherein the FOUP25 is located in the attaching position, even when the opener-side door65 and the FOUP-side door61 are removed from therespective openings60a,101a due to the door opening andclosing mechanism109, entering of the outside air into the FOUPinternal space34 and theinterface space29 can be prevented.

Therespective FOUP openers26a to26d are arranged in the left and right directions Y, and configured to operate individually.FIG. 1 illustrates a state wherein thefirst FOUP opener26a positioned on the most left side (in the drawing) opens the correspondingfront opening120. In addition,FIG. 1 shows a state wherein theFOUP openers26b to26d other than thefirst FOUP opener26a close the correspondingfront openings120, respectively.

For eachFOUP opener26a to26d, amovable region108 is set, in which eachdoor61,65 can be moved to the release position, due to the door opening andclosing mechanism109. Themovable region108 of eachFOUP opener26a to26d is set in theinterface space29 and is defined near thefront wall110 in theinterface space29.

Thewafer transfer robot27, in this embodiment, is achieved by a horizontal articulated robot of a selective compliance assembly robot arm (SCARA) type. Therobot27 is located in theinterface space29 and is configured to include arobot arm41, a horizontal drive means42a, a vertical drive means42b, abase43, and acontroller44.

Therobot arm41 has a link structure including a plurality oflink members41a to41c which are successively connected in a direction from a proximal end to a distal end. Arobot hand40 is provided at the distal end of therobot arm41. Therobot hand40 has a holding structure which can hold thewafer24. The holding of thewafer24 is intended herein to express a state wherein thewafer24 can be carried by using thehand40. Accordingly, thewafer24 may be mounted onto, sucked or held by, thehand40.

The horizontal drive means42a is adapted to drive therespective link members41a to41c of therobot arm41 to be angularly displaced about joint axes A0 to A2, respectively. Therobot arm41 can drive therobot hand40 by using the horizontal drive means, such that therobot hand40 can be displaced in any position on a horizontal plane in a movable region, due to the relative angular displacement of eachlink member41a to41c. The horizontal drive means42a includes a motor adapted to provide angular displacement in accordance with a signal to be given from thecontroller44, and a power transmission mechanism adapted to transmit power of the motor to each link member. The motor and the power transmission mechanism are provided for eachlink member41a to41c.

The vertical drive means42b is adapted to drive therobot arm41 to be displaced in the upward and downward directions Z. The vertical drive means42b includes a fixed portion and a movable portion, wherein the movable portion can be angularly displaced in the upward and downward directions relative to the fixed portion. The vertical drive means42b further includes a motor adapted to provide angular displacement in accordance with a signal to be provided from thecontroller44, and a power transmission mechanism which converts power of the motor into power for direct advance of the movable portion relative to the fixed portion and transmit the power to the movable portion. The fixed portion of the vertical drive means42b is supported by thebase43. Thebase43 is adapted to support the vertical drive means42b and is fixed to the interfacespace forming portion28.

Thecontroller44 is adapted to control the horizontal drive means42a and the vertical drive means42b in accordance with a transfer instruction to be inputted from a predetermined operational program or from a user and move therobot hand40 to a preset position. Thecontroller44 includes a memory circuit for storing a predetermined program, an operational circuit for calculating the operational program stored in the memory circuit, and an output means adapted to provide signals expressing results of the calculation given from the operational circuit to the horizontal drive means42a and the vertical drive means42b. For example, the memory circuit can be achieved by a random access memory (RAM) and/or a read only memory (ROM), and the operational circuit can be realized by a central processing unit (CPU).

Due to fixation of a proximal end of therobot arm41 to the movable portion of the vertical drive means42b, thecontroller44 can drive and displace therobot hand40 of therobot arm41 to any position in the forward and backward directions X, left and right directions Y and upward and downward directions Z, in a movable range. In addition, due to the control of the horizontal drive means42a and the vertical drive means42b by virtue of thecontroller44, thewafer24 held by therobot hand40 can be transferred. Thus, thewafer24 can be transferred, along a predetermined route, between each FOUP25 and thewafer processing apparatus22.

Therobot hand40 passes through thefront opening120 and is advanced into the FOUPinternal space34 while thecorresponding opener26a to26d opens the FOUP-side door61 so as to hold awafer24 contained in the FOUP25. Thereafter, therobot hand40 is moved through theinterface space29 while holding thewafer24, passes through therear opening121, and is advanced into theprocessing space33 of thesemiconductor processing apparatus22 so as to place the heldwafer24 onto a presetwafer holding position107. Alternatively, therobot hand40 passes through therear opening121, and is advanced into theprocessing space30 so as to hold thewafer24 held in thewafer holding position107. Subsequently, therobot hand40 is moved through theinterface space29 while holding thewafer24, passes through thefront opening120, and is advanced into the FOUPinternal space34 so as to transfer the heldwafer24 to a position for containing it in the FOUP25.

In this embodiment, since the fourFOUP openers26a to26d are provided, therobot hand40 is set to be able to take out and put in eachwafer24 relative to each FOUP25 supported by eachFOUP supporting portion31 of eachopener26. Therobot hand40 can also carry thewafer24 taken out from the FOUP25 to a holding position set in thealigner56 as well as can carry thewafer24 taken out from the holding position of thealigner56 into thewafer processing apparatus22.

Thealigner56 is located in theinterface space29 and positioned more right than thefourth FOUP opener26d which is positioned on the most right side (in the drawing) of the plurality ofFOUP openers26a to26d. Thealigner56 has a holding portion for holding eachwafer24, and is configured to rotate thewafer24 held by the holding portion so as to align a notch or ori-flat (orientation flat) formed in thewafer24 with a predetermined direction. Accordingly, when the so-alignedwafer24 is held by therobot hand40, thewafer24 can be located in theprocessing apparatus22 with its orientation adjusted. In this way, theprocessing apparatus22 can provide a predetermined process with the orientation of eachwafer24 being properly controlled.

A central position of eachwafer24 held by thealigner56 is set at approximately the center of theinterface space29 in the forward and backward directions X. Thealigner56 is located in a position that does not interfere with the travel of therobot hand40 to eachFOUP opener26. As such, in this embodiment, thealigner56 is positioned more right than thefourth FOUP opener26d which is positioned on the most right side.

As described above, thewafer transfer robot27 is located in theinterface space29, and serves to mainly move therobot hand40 in theinterface space29. Thewafer transfer robot27 is configured to make therobot hand40 pass through thefront opening120 so as to enable eachwafer24 to be taken out from the FOUPinternal space34 as well as to enable thewafer24 to be placed into the FOUPinternal space34. Thewafer transfer robot27 is also configured to have the robot hand pass through therear opening121 so as to enable eachwafer24 to be taken out from thewafer holding position107 of theprocessing space30 as well as to enable thewafer24 to be placed in thewafer holding position107 of theprocessing space30. Furthermore, thewafer transfer robot27 is configured such that it can pass through the fourfront opening120 respectively provided in the fourFOUP openers26a to26d.

Accordingly, thewafer transfer robot27 is configured such that it can carry therobot hand40 in the forward and backward directions X over a distance greater than the length B in the forward and backward directions of theinterface space29. Thewafer transfer robot27 is configured to enable therobot hand40 to be moved in the left and right directions Y such that it can access the FOUP25 supported by eachFOUP opener26a to26d. Moreover, in this embodiment, thewafer transfer robot27 is configured to enable therobot hand40 to be moved in the left and right directions Y such that it can access thealigner56.

Thebase43 is fixed to the interfacespace forming portion28, at which the predetermined pivot axis A0 is set. The pivot axis A0, in this embodiment, extends in the vertical direction, and is positioned near therear wall111 in theinterface space29. The pivot axis A0 is defined in a central position between the mostleft FOUP opener26a and the mostright FOUP opener26d in the left and right directions Y.

Therobot arm41 is configured to have a link structure in which the plurality oflink members41a to41c are connected with one another. A proximal end therobot arm41 is defined at one end of an arrangement in which the plurality oflink member41a to41c are successively arranged, and a distal end thereof is defined at the other end of the arrangement. The proximal end of therobot arm41 is fixed to the movable portion of the vertical drive means42b, and is connected with thebase43 via the vertical drive means42b. At the distal end of therobot arm41, therobot hand40 is provided. Therobot arm41 is configured such that the proximal end can be angularly displaced about the pivot axis A0.

Specifically, therobot arm41 includes the first tothird link members41a,41b,41c. Each of thelink members41a to41c is formed into an elongated shape extending in its longitudinal direction. Thefirst link member41a is connected, at its oneend45a in its longitudinal direction, with the movable portion of the vertical drive means42b. Thefirst link member41a is configured such that it can be angularly displaced about the pivot axis A0 relative to the movable portion of the vertical drive means42b. At theother end46a in the longitudinal direction of thefirst link member41a, the first joint axis A1 is set, which is parallel with the pivot axis A0. Accordingly, the first joint axis A1 is moved along with movement of thefirst link member41a. The longitudinal direction of thefirst link member41a is defined by a line connecting the pivot axis A0 with the first joint axis A1.

Thesecond link member41b is connected, at its oneend45b in its longitudinal direction, with theother end46a in the longitudinal direction of thefirst link member41. Thesecond link member41b is configured such that it can be angularly displaced about the first joint axis A1 relative to thefirst link member41a. At theother end46b in the longitudinal direction of thesecond link member41b, the second joint axis A2 is set, which is parallel with the pivot axis A0. Accordingly, the second joint axis A2 is moved along with movement of thesecond link member41b. The longitudinal direction of thesecond link member41b is defined by a line connecting the first joint axis A1 with the second joint axis A2.

Thethird link member41c is connected, at its oneend45c in its longitudinal direction, with theother end46b in the longitudinal direction of thesecond link member41b. Thethird link member41c is configured such that it can be angularly displaced about the second joint axis A2 relative to thesecond link member41b. At theother end46c in the longitudinal direction of thethird link member41c, therobot hand40 is provided. Accordingly, therobot hand40 is moved along with movement of thethird link member41c. The longitudinal direction of thethird link member41c is defined by a line connecting the second joint axis A2 with the central position A3 of thewafer24 which is held by therobot hand40.

In this manner, the robot arm has the link structure comprising the threelink members41a to41c. The horizontal drive means42a includes first to third motors. The first motor is adapted to rotate and drive thefirst link member41a about the pivot axis A0. The second motor is adapted to rotate and drive thesecond link member41b about the first joint axis A1. The third driving source is a motor which serves to rotate and drive thethird link member41c about the second joint axis A2. As such, the horizontal drive means42a can angularly displace the first tothird link members41a to41c, individually, about the corresponding angular displacement axes A0 to A2, respectively.

As shown inFIG. 2, thesecond link member41b is located above thefirst link member41a. Thus, thesecond link member41b can be moved in a position which is overlapped with thefirst link member41a in the upward and downward directions Z, thereby to prevent interference of thefirst link member41a with thesecond link member41b. Similarly, thethird link member41c is located above thesecond link member41b. Accordingly, thethird link member41c can be moved in a position which is overlapped with thesecond link member41b, as such preventing each interference of thefirst link member41a to thethird link member41c.

FIG. 3 is a plan view showing thewafer transfer apparatus23, which is simplified, for explaining a length of eachlink member41a to41c. Due to the angular displacement of eachlink member41a to41c about each corresponding angular displacement axis A0 to A2, therobot arm41 can be transformed into its minimum state. A minimum transformed state means a transformed state wherein a distance, defined from the pivot axis A0 to an arm portion, which extends in the horizontal direction and is the farthest in the radial direction from the pivot axis A0, is the minimum. More specifically, the minimum transformed state means a transformed state wherein a distance, from the pivot axis A0 to an arm portion or a portion of thewafer24, which is the farthest in the radial direction from the pivot axis A0, with thewafer24 being held by therobot arm41, is the minimum.

Hereinafter, in the minimum transformed state, the distance, from the pivot axis A0 to the arm portion or wafer portion, which is farthest in the radial direction relative to the pivot axis A0, will be referred to as “the minimum rotation radius R of the robot.” The length between thefront wall110 and therear wall111 constituting theinterface space29 in the forward and backward directions X will be referred to as “the length B of the interface space in the forward and backward directions.”

In this embodiment, the minimum rotation radius R of the robot is longer than a half (½) of the length B of the interface space in the forward and backward directions. In addition, the minimum rotation radius R is set to be equal to or less than a subtracted value (B−L0) obtained by subtracting a distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0, from the length B of the interface space in the forward and backward directions (i.e., B/2<R≦B−L0). Accordingly, even when therobot arm41 is transformed into its minimum transformed state, an amount of angular displacement of therobot arm41 is restricted such that it can be angularly displaced about the pivot axis A0 within an allowable angular displacement range that can prevent interference of therobot arm41 with therear wall111. In this embodiment, the allowable angular displacement range is set to be smaller than 360 degrees, for example, about 180 degrees, about the pivot axis A0. Thus, interference of therobot27, which is maintained in the minimum transformed state, with thefront wall110 as well as with therear wall111 can be prevented, as long as it is operated within the allowable angular displacement range.

The distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0 is set at, at least, a value smaller than ½ of the length B in the forward and backward directions of the interface space (i.e., L0<B/2). In this embodiment, the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0 is set to be less than ⅕ of the length B in the forward and backward directions of the interface space (i.e., L0<B/5). Furthermore, the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0 is set to be greater by a predetermined gap length Q than a radius T2 of an outer circumference of thefirst link member41a about the pivot axis A0, over the whole area wherein the outer circumference of thefirst link member41a is on the opposite side of the first joint axis A1 with respect to the pivot axis A0 (i.e., L0=T2+Q). The predetermined gap length Q is sufficient for preventing the interference that would be otherwise caused by the robot, and in this embodiment, it is set at 30 mm.

More specifically, in this embodiment, the minimum rotation radius R of the robot is set to exceed ½ of an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis and a length E of a robot invasion restricted region, which is set for eachFOUP opener26 and is measured from thefront wall110, in the forward and backward directions X, on the rear wall side, from the length B in the forward and backward directions of the interface space, as well as set to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<R≦B−L0−E). Thus, interference of therobot27, which is maintained in its minimum transformed state, with eachFOUP opener26 can be prevented.

A distance from the pivot axis A0 to an end of thefirst link member41a, which is the farthest in the axial direction toward the first joint axis A1 relative to the pivot axis A0, is referred to as a first link distance L1. The first link distance L1 is set to exceed ½ of the allowable length (B−L0−E) described above and to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E). Thefirst link member41a is formed such that a radius T1 of the outer circumference of thefirst link member41a about the first joint axis A1 is equal to or less than a value to be obtained by subtracting the distance L11 (first axis-to-axis distance) between the pivot axis A0 and the first joint axis A1, from the allowable length (B−L0−E), over the whole area wherein the outer circumference of thefirst link member41a is on the opposite side of the pivot axis A0 with respect to the first joint axis A1 (i.e., T1≦B−L0−E−L11).

Thefirst link member41a is formed such that the radius T2 of the outer circumference of thefirst link member41a about the pivot axis A0 is less than the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0, over the whole area wherein the outer circumference of thefirst link member41a is on the opposite side of the first joint axis A1 with respect to the pivot axis A0 (i.e., T2<L0). Consequently, even in the case where thefirst link member41a is angularly displaced by 90 degrees, from a state wherein the longitudinal direction of thefirst link member41a is coincident with the forward and backward directions X, in one of the circumferential directions about the pivot axis A0, or alternatively, even in the case where it is angularly displaced by 90 degrees from the above state in the other circumferential direction about the pivot axis A0, interference of thefirst link member41a with therear wall111 can be prevented.

In this embodiment, the first axis-to-axis distance L11 between the pivot axis A0 and the first joint axis A1 and the second axis-to-axis distance L12 between the first joint axis A1 and the second joint axis A2 are set to be the same. As used herein, the term “the same” is intended to imply a state that is substantially the same, as such referring to both the same and substantially the same states. In this embodiment, a distance from the second joint axis A2 to an end of thesecond link member41b, which is the farthest in the direction toward the first joint axis A1 relative to the second joint axis A2, is referred to as a second link distance L2. The second link distance L2 is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E) (i.e., (B−L0−E)/2<L2≦B−L0−E).

Thesecond link member41b is formed such that a radius T3 of the outer circumference of thesecond link member41b about the first joint axis A1 is equal to or less than a value (B−L0−E−L11) to be obtained by subtracting the first axis-to-axis distance L11 from the allowable length (B−L0−E), over the whole area wherein the outer circumference of thesecond link member41b is on the opposite side of the second joint axis A2 with respect to the first joint axis A1 (i.e., T3≦B−L0−E−L11). Thesecond link member41b is formed such that a radius T4 of the outer circumference of thesecond link member41b about the second joint axis A2 is smaller than the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0, over the whole area wherein the outer circumference of thesecond link member41b is on the opposite side of the first joint axis A1 with respect to the second joint axis A2 (i.e., T4<L0).

In this embodiment, in a state wherein therobot hand40 holds thewafer24, a distance from the second joint axis A2 to an end of thethird link member41c or a wafer portion, which is the farthest from the second joint axis A2 in the radial direction with respect to the second joint axis A2, is referred to as a third link distance L3. The third link distance L3 is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E). Thethird link member41c is formed such that a radius T5 of the outer circumference of thethird link member41c about the second joint axis A2 is smaller than the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0, over the whole area wherein the outer circumference of thethird link member41c is on the opposite side of the wafer holding central position A3 with respect to the second joint axis A2 (i.e., T5<L0).

In this embodiment, the first link distance L1 and the second link distance L2 are set to be equal to the allowable length (B−L0−E). The first axis-to-axis distance L11 and the second axis-to-axis distance L12 are set to be the same distance that enables thewafer24 supported by eachFOUP opener26a to26d to be taken out therefrom. In this embodiment, the third link distance L3 is also set to be the same as the allowable length (B−L0−E). As shown inFIG. 3, therobot hand40 is set such that it can hold thewafer24 in a state wherein thefirst link member41a and thesecond link member41b are extended in a straight line.

In the case where thethird link member41 is located in a position to hold thewafer24 contained in thefirst FOUP25a supported by thefirst FOUP opener26a, a distance in the forward and backward directions X from the second joint axis A2 to the pivot axis A0 is designated by S1. A distance in the left and right directions from the second joint axis A2 to the pivot axis A0 is designated by S2. In addition, a distance obtained by summing up the first axis-to-axis distance L11 and the second axis-to-axis distance L12 is expressed by (L11+L12).

In this embodiment, each axis-to-axis distance L11, L12 is set to satisfy the following relation ship: (L11+L12)=(S1²+S2²)^0.5. Because each axis-to-axis distance L11, L12 is set to be equal, each axis-to-axis distance L11, L12 is defined as ((S1²+S2²)/4)^0.5. Thus, as shown inFIG. 3, therobot hand40 can reach thewafer24 contained in thefirst FOUP25a while the longitudinal direction of thefirst link member41a and the longitudinal direction of thesecond link member41b are arranged to constitute together a straight line. Since the pivot axis A0 is located in a central position relative to theFOUP openers26a to26d, therobot hand40 can also reach thewafer24 contained in thefourth FOUP25d while the longitudinal direction of thefirst link member41a and the longitudinal direction of thesecond link member41b are arranged to constitute together a straight line. In this way, since thefirst link member41a and thesecond link member41b can take a form to constitute together a straight line, each of the first axis-to-axis distance L11 and second axis-to-axis distance L12 can be significantly reduced.

In addition, therobot hand40 may be configured to reach thewafer24 contained in thefirst FOUP25a orfourth FOUP25d while thethird link member41c is inclined to the forward and backward directions X. As such, each of the first axis-to-axis distance L11 and second axis-to-axis distance L12 can be further reduced.

In this embodiment, each space in the left and right directions Y between the wafer central positions A3 of thewafers24 contained in thefirst FOUP25a tofourth FOUP25d is designated by W. In addition, in the state wherein therobot hand40 reaches thewafer24 contained in thefirst FOUP25a, an angle at which thethird link member41 is inclined relative to the forward and backward directions X is expressed by θ. In this state, a distance from the wafer central position A3 to the second joint axis A2 is designated by H. Also in this state, a value (S1−L11) to be obtained by subtracting the first axis-to-axis distance L11 from the distance S1 in the forward and backward directions from the second joint axis A2 to the pivot axis A0 is expressed by C. Using these expressions, the first axis-to-axis distance L11 can be expressed as follows.
(2·L11)²≧(L11+C)²+(1.5·W−H·Sin θ)²

For example, in the case where C=0, θ=0, and W=505 mm, each axis-to-axis distance L11, L12 is equal to or greater than 437.3 mm. Now, assume that the length E of the robot invasion restricted region in the forward and backward directions X, which is set for eachFOUP opener26 and is measured from thefront wall110 on the rear wall side, is 100 mm. In addition, assume that the distance L0 in the forward and backward directions from therear wall111 to the pivot axis A0 is 65 mm, and that a distance L10 (R−L11) to be obtained by subtracting the first axis-to-axis distance L11 from the minimum rotation radius R of the robot is 50 mm. The resultant length B in the forward and backward directions of the interface space is equal to or greater than 652.3 mm (i.e., B≧L11+E+L0+L10). In other words, if the length B in the forward and backward directions of the interface space is 652.3 mm, thewafer24 contained in each of the first andfourth FOUPs25a,25d supported by each correspondingFOUP opener26a,26d can be taken out, by setting each axis-to-axis distance L11, L12 at 437.3 mm. Of course, thewafer24 contained in each of the second andthird FOUPs25b,25c, which are located nearer to the pivot axis A0 than the first andfourth FOUPs25a,25d, can also be taken out.

In this embodiment, the length B in the forward and backward directions of the interface space is 694 mm. The minimum rotation radius R of the robot is set at 485 mm, and the first axis-to-axis distance L11 and the second axis-to-axis distance L12 are each set at 425 mm. In the state wherein thewafer24 is held by therobot hand40, the distance H from the second joint axis A2 to the wafer central position A3 is set at 320 mm. In addition, the third link distance L3 is set at 470 mm.

For example, if θ=5°, H=330 mm, and the other conditions are the same as described above, each axis-to-axis L11, L12 to be obtained is equal to or greater than 420.4 mm, and the length B in the forward and backward directions of the interface space is to be equal to or greater than 635.4 mm. Alternatively, if C=10 mm, θ=5°, H=330 mm, and the other conditions are the same as described above, each axis-to-axis L11, L12 to be obtained is equal to or greater than 417.5 mm and the length B in the forward and backward directions of the interface space is to be equal to or greater than 632.5 mm.

By inclining the longitudinal direction of thethird link member41c relative to the forward and backward directions X in the state wherein therobot hand40 reaches thewafer24, the wafer contained in eachFOUP25a to25d can be taken out without unduely extending thefirst link member41a and thesecond link member41b.

In the embodiment described above, due to the pivot axis A0 arranged near therear wall111 and due to the minimum rotation radius R of therobot arm41, which is set to exceed ½ of the subtracted value (B−L0) and to be equal to or less than the subtracted value (B−L0), a gap can be securely provided between therobot arm41, which is in the minimum transformed state, and thefront wall101, as such preventing interference of therobot arm41 with thefront wall101. Accordingly, therobot hand40 can be located, on both sides in the left and right directions Y, with respect to a reference line P0 extending in the forward and backward directions X and including the pivot axis A0.

In addition, since therobot arm41 can be operated in an operational range excluding such a range that would potentially interfere with therear wall111, the interference of the robot with therear wall111 can also be prevented. Accordingly, while the length B in the forward and backward directions of the read space is relatively small, eachwafer24 contained in a plurality of, for example, four, FOUPs, i.e., the first tofourth FOUP25a to25d, supported by the fourFOUP openers26a to26d, can be taken out, by using therobot arm41 having the link structure comprising the threelink members41a to41c.

In this embodiment, by setting the minimum rotation radius R of the robot to be equal to or less than the allowable length (B−L0−E), even though therobot arm41 taking its minimum transferred state approaches nearest relative to thefront wall101, entering of a part of therobot arm41 into the robot invasion restricted region E of eachFOUP opener26a to26d can be prevented. Thus, interference between therobot arm41 with eachFOUP opener26a to26d can be prevented, regardless of a movable range or state of eachFOUP opener26a to26d.

The first to third link distances L1 to L3 are set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E). As a result, the length of eachlink member41a to41c can be significantly enlarged. Therefore, even in the case where the length B in the forward and backward directions of the interface space is relatively small, therobot hand40 can be extended to a position which is significantly spaced away from the pivot axis A0 on both sides in the left and right directions Y. Thus, even in the case where the number of theFOUP openers26 is quite increased, thewafer24 can be carried with the simple link structure as described above. In this embodiment, the first to third link distances L1 to L3 are each set to be the same as the allowable length (B−L0−E). Consequently, interference of therobot arm41 with thefront wall110 as well as with eachFOUP opener26 can be prevented, and the length of eachlink member41a to41c can be increased to the maximum.

With the increase of the link length of eachlink member41a to41c of therobot arm41, the movable range of therobot arm41 can be enlarged with respect to the left and right directions Y. Accordingly, as compared with the second related art, the running means which is adapted to drive therobot27 to run in the left and right directions Y can be excluded, thus eliminating the direct acting mechanism. As such, occurrence of dust to be associated with the direct acting mechanism can be prevented, and hence degradation of cleanliness in theinterface space29 due to such dust can be avoided. Additionally, the elimination of the running means can ensure downsizing and weight reduction of therobot27.

In addition, with the increase of the link length of eachlink member41a to41c of therobot arm41, the robot hand can reach a predetermined position in a wider range. Furthermore, increase of the number of the link members can be controlled, as such simplifying the structure of therobot27. In addition, redundancy of therobot27 can be reduced, thus simplifying teaching works concerning control and transformed states for therobot arm41. Therefore, possibility of collision of therobot arm41 with the interfacespace forming portion28 as well as with eachFOUP opener26 can be reduced.

As described above, in this embodiment, scattering of dust can be suppressed due to exclusion of the running means, as well as, the interference of the robot with the interior of thewafer transfer apparatus23 can be prevented, as such providing thewafer transfer apparatus23 comprising thewafer transfer robot23 which has a significantly simplified structure and can be readily controlled. In addition, the number of theFOUP openers26 can be increased without enlarging the length B in the forward and backward directions of theinterface space29. With the increase of the number of theFOUP openers26, carrying, attaching and detaching operations of each FOUP25 relative to thewafer transfer apparatus23 and a transfer operation of each wafer contained in each FOUP25 held by thewafer transfer apparatus23 can be performed in parallel, thereby to enhance the working efficiency.

Because the length B in the forward and backward directions of theinterface space29 can be reduced, a space for installment of thewafer transfer apparatus23 can be down-sized. Therefore, restrictions regarding the installment space can be lightened, thus in turn facilitating installment of thewafer processing equipment20. With reduction of the length B in the forward and backward directions of theinterface space29, as compared with a case in which the length B in the forward and backward directions of theinterface space29 is longer, the cleanliness in theinterface space29 can be enhanced as well as the yield can be improved, by using theinterface space controller100 provided with the same function.

In this embodiment, the length B in the forward and backward directions of the interface space can be reduced by designing therobot hand40 such that the longitudinal direction of thethird link member41c can be inclined relative to the forward and backward directions X in the state wherein therobot hand40 reaches the correspondingwafer24. Thus, even in the case where the first and second axis-to-axis distances L11, L12 are set to be shorter in order to prevent interference of therobot hand40 with the interfacespace forming portion28 and/or eachFOUP opener26, holding of thewafer24, which is held by the FOUP25 supported by each corresponding FOUP opener, can be performed with ease.

Since the length of eachlink member41a to41c can be increased, as compared with a case in which the length of eachlink member41a to41c is shorter, a transfer speed of the robot hand can be enhanced, even with the angular speed upon angular displacement about the corresponding pivot axes A0 to A2 being the same. By driving both of thefirst link member41a andsecond link member41b, force of inertia can be reduced. Due to this function, the transfer speed of therobot hand40 can also be enhanced. With such enhancement of the transfer speed of therobot hand40, the time required for carrying eachwafer24 can be reduced, thereby to enhance the working efficiency.

FIG. 4 is a diagram showing a carrying operation, which is simplified, for carrying thewafer24 contained in thefirst FOUP25a to thealigner56. The carrying operation proceeds in the order of fromFIG. 4(1) toFIG. 4(7). The carrying operation shown inFIG. 4 is stored in thecontroller44, with respect to the transfer route and passing through points of therobot hand40. Thecontroller44 serves to control the horizontal drive means42a and the vertical drive means42b by executing a predetermined operational program, such that therobot hand40 passes through a plurality of points along the transfer route. Consequently, thewafer transfer robot27 can carry eachwafer24 contained in thefirst FOUP25a to thealigner56.

First, therobot arm41 is moved vertically up to thewafer24 to be held, and then transformed such that thefirst link member41a and thesecond link member41b are extended in a straight line, as shown inFIG. 4(1), so as to hold thewafer24 contained in thefirst FOUP25a by using thehand40. Next, as shown inFIG. 4(2), thefirst link member41a and thesecond link member41b are angularly displaced about the corresponding angular displacement axes A0, A1, respectively, so as to move thethird link member41c in the backward direction X2 into theinterface space29 together with thewafer24.

Subsequently, thefirst link member41a and thesecond link member41b are further angularly displaced about the corresponding angular displacement axes A0, A1, respectively, so as to move thethird link member41c in parallel to the left and right directions Y, toward thealigner56 located in a position far away from thefirst FOUP opener26a in the left and right directions Y. At this time, because the first axis-to-axis distance L11 and the second axis-to-axis distance L12 are set to be equal, as shown inFIGS. 4(3) and4(4), thesecond link member41b is angularly displaced about the first joint axis A1, in an amount of angular displacement per unit time, which is twice the amount of angular displacement per unit time, relative to the angular displacement of thefirst link member41a about the pivot axis A0. In this manner, thethird link member41c can be moved in parallel to the left and right directions Y, without angularly displacing thethird link member41c about the second joint axis A2, and without altering the attitude of thethird link member41c.

In the case of locating thethird link member41c on thealigner56 with its attitude altered, as shown inFIGS. 4(5) to4(7), thewafer24 can be located in a holding position set in thealigner56, by angularly displacing the first tothird link members41a to41c about the corresponding angular displacement axes A0 to A2, respectively. In order to enable thealigner56 to hold thewafer24, after therobot arm41 has held thewafer24 and by the time it carries thewafer24 to thealigner56 so as to make thealigner56 hold thewafer24, the position in the upward and downward directions of therobot arm41 is adjusted by the vertical drive means42b. In this manner, thewafer transfer robot27 can carry thewafer24, which has been contained in thefirst FOUP25a, to thealigner56.

FIG. 5 is a diagram showing a carrying operation, which is simplified, for carrying thewafer24 supported by thealigner56 into theprocessing space30. The carrying operation proceeds in the order of fromFIG. 5(1) toFIG. 5(7). Similar to the case shown inFIG. 4, thewafer transfer robot27 can carry thewafer24 held by thealigner56 into theprocessing space30, by controlling the horizontal drive means42a and the vertical drive means42b in accordance with the predetermined program.

In the case of carrying thewafer24 into theprocessing space30, thehand40 should be directed in the backward direction X2. Accordingly, as shown inFIG. 5(1), from a state wherein the second joint axis A2 has been moved in the backward direction X2 in theinterface space29 while thethird link member41c holding thewafer24, thethird link member41c is angularly displaced about the second joint axis A2 as well as the second joint axis A2 is moved in the forward direction X1 in theinterface space29. In the example shown inFIG. 5, after thethird link member41c has been angularly displaced by about120 degrees, the second joint axis A2 is moved in the forward direction X1 in theinterface space29, and thethird link member41c is then further angularly displaced.

Thus, the orientation of thethird link member41a can be altered by 180 degrees in theinterface space29 without any interference of thethird link member41a with thefront wall110,rear wall111 and eachFOUP opener26. Accordingly, as shown inFIGS. 5(2) to5(6), after the orientation of thethird link member41c has been altered, as shown inFIG. 5(7), thewafer24 can be carried into theprocessing space30. In order to enable therobot arm41 to be moved into theprocessing space30 after it has held thewafer24 and by the time it is moved toward theprocessing space30, the position in the upward and downward directions of therobot arm41 is controlled by the vertical drive means42b. In this way, thewafer transfer robot27 can carry thewafer24, which has been held by thealigner56, into theprocessing space30.

FIG. 6 is a diagram showing a carrying operation, which is simplified, for carrying thewafer24 located in theprocessing space30 to thefirst FOUP25a. Similar to the case shown inFIG. 4, the controller controls the horizontal drive means42a and the vertical drive means42b in accordance with the predetermined program so that thewafer transfer robot27 can carry thewafer24 contained in theprocessing space30 to thefirst FOUP25a.

First, therobot arm41 is moved upward and downward to a position of thewafer24 to be held as well as therobot arm41 is transformed, as shown inFIG. 6(1), so as to hold thewafer24 in theprocessing space30. Subsequently, as shown inFIG. 6(2), thefirst link member41a and thesecond link member41b are angularly displaced about the corresponding angular displacement axes A0, A1, respectively, and thethird link member41c is moved in the forward direction X1, so as to move thethird link member41c and thewafer24 into the interior of theinterface space29. Thereafter, as shown inFIGS. 6(3) and6(4), while the position of the second joint axis A2 is adjusted in order to prevent interference due to thethird link member41c, thethird link member41c is rotated about the second joint axis A2 to alter its attitude, thus changing the orientation of thethird link member41c. Next, as shown inFIGS. 6(4) and6(5), thefirst link member41a and thesecond link member41b are angularly displaced about the corresponding angular displacement axes A0, A1, respectively, so as to move thethird link member41c in parallel to the left and right directions Y. Thereafter, as shown inFIG. 6(6), a portion on the robot hand side of thethird link member41c is positioned to face the front opening as well as maintained in an attitude which is substantially parallel to the forward and backward directions X. In this state, the position of thehand40 in the upward and backward directions is adjusted to enable the wafer to be contained in the FOUP. As such, the wafer is contained in the space in the FOUP25 as shown inFIG. 6(7).

FIG. 7 is a diagram showing a state in which thewafer24 is located in its receiving and transferring positions of the embodiment according to the present invention.FIGS. 7(1) to7(4) depict states wherein thewafers24 contained in the first tofourth FOUPs25a to25d are held, respectively.FIG. 7(5) shows a state in which thewafer24 is located at thealigner56.FIGS. 7(6) and7(7) show states wherein thewafer24 is located in positions set in theprocessing space30, respectively. As illustrated, this embodiment can be configured to include the robot arm having the three-link type structure so as to enable receiving and transferring of thewafers24 in the FOUPs25 supported by the fourFOUP openers26a to26d, respectively.

While, this embodiment comprises the singlethird link member41c provided in therobot hand40, it is not limited to this aspect. Namely, in the present invention, it is also contemplated that a plurality of, for example, two,third link members41c may be provided.

For example, in the case where a plurality ofthird link members41c are provided, thesethird link members41c are provided to be arranged in the upward and downward directions Z, respectively. Eachthird link member41c is connected, at its oneend45c in the longitudinal direction, with theother end46b in the longitudinal direction of thesecond link member41b. Eachthird link member41c is configured such that it can be angularly displaced, individually, about the second joint axis A2 relative to thesecond link member41b. In addition, eachthird link member41c is provided with therobot hand40 formed at the other end thereof in the longitudinal direction. Due to arrangement of eachthird link member41c in a region different in the upward and downward directions, even though they are angularly displaced, individually, about the second joint axis A2, mutual interference between thethird link members41c can be prevented. In addition, due to such provision of the plurality ofthird link members41c, the number of sheets of the wafers that can be carried at a time can be increased, as such enhancing the working efficiency. It should be appreciated that the number of the third link members is not limited to one or two but three or morethird link members41c may be provided. It is preferred that eachthird link member41c is formed to have the same shape.

FIG. 8 is a plan view showing thewafer transfer apparatus23 including threeFOUP openers26.FIG. 9 is a plan view showing thewafer transfer apparatus23 including twoFOUP openers26. InFIGS. 8 and 9, one example of additional working forms of arobot27 is depicted by chain double-dashed lines. Thewafer transfer robot27 shown inFIGS. 8 and 9 is configured similarly to thewafer transfer robot27 used in thewafer transfer apparatus23 including the fourFOUP openers26. Accordingly, thewafer transfer robot27 can carry each wafer without causing any interference with thefront wall110 and therear wall111, also in the case of including the two or threeFOUP openers26. As such, there is no need for changing the configuration of the robot depending on the number of theFOUP openers26, thereby to enhance applicability for general purposes.

FIG. 10 is a plan view showing awafer transfer apparatus23A which is a second embodiment of the present invention, and is somewhat simplified. Thewafer transfer apparatus23A of the second embodiment includes portions similar to those in thewafer transfer apparatus23 of the first embodiment described above. Thus, such like parts are not described here, and designated by like reference numerals. Specifically, thewafer transfer apparatus23A of the second embodiment is different from the first embodiment in the length of thewafer transfer robot27, but is the same as the first embodiment in regard to the other configuration.

The first embodiment is configured such that therobot hand40 reaches thewafer24 contained in thefirst FOUP25a with thefirst link member41a and thesecond link41b extended together in a straight line. However, the present invention is not limited to this aspect. Namely, in the second embodiment, therobot hand40 reaches thewafer24 contained in thefirst FOUP25a with the longitudinal direction of thelink member41a and the longitudinal direction of thesecond link member41b defining a predetermined angle α.

In the second embodiment, angular positions of thefirst link member41a and thesecond link member41b are respectively set such that therobot hand40 reaches thewafer24, with the longitudinal direction of thethird link member41c being coincident with the forward and backward directions X. Namely, in the second embodiment, thehand40 reaches thewafer24, with the longitudinal direction of thethird link member41c being coincident with the forward and backward directions X, and thethird link member41c is then moved in parallel to the backward direction X2, so as to carry thewafer24 into theinterface space29. Thus, even in the case where a gap between the wafer held by thehand40 and the front opening101a as well as theopening60a of the FOUPmain body60 is relatively small, collision of thewafer24 with eachopening101a,60a can be prevented.

Also in the second embodiment, by locating the pivot axis A0 near therear wall111 and by setting the minimum rotation radius R of therobot arm41 to exceed ½ of the subtracted value (B−L0) described above and to be equal to or less than the subtracted value (B−L0), the same effect as in the first embodiment can be obtained.

FIG. 11 is a plan view showing awafer transfer apparatus23B which is a third embodiment of the present invention, and is somewhat simplified. InFIG. 11, one example of additional working forms of arobot27 is depicted by chain double-dashed lines. Thewafer transfer apparatus23B of the third embodiment includes portions similar to those in thewafer transfer apparatus23 of the first embodiment described above. Thus such like parts are not described here, and designated by like reference numerals. Specifically, thewafer transfer apparatus23B of the third embodiment is different from the first embodiment in the length of thewafer transfer robot27, but is the same as the first embodiment in regard to the other configuration.

In the first embodiment, the first axis-to-axis distance L11 and the second axis-to-axis distance L12 are of the same length. However, this invention is not limited to this aspect. In the third embodiment, there is some difference in the length between the first axis-to-axis distance L11 and the second axis-to-axis distance L12, and the first axis-to-axis distance L11 is provided to be slightly longer than the second axis-to-axis distance L12. In this case, as shown inFIG. 11, when angularly displacing thesecond link member41b about the first joint axis A1, in an amount of angular displacement per unit time, which is twice the amount of angular displacement per unit time, relative to the angular displacement of thefirst link member41a about the pivot axis A0 while the angular displacement of thethird link member41c about the second joint axis A2 is stopped, the attitude of thethird link member41c is changed slightly.

When therobot hand40 is advanced from one end to the other end in the left and right directions Y relative to the pivot axis A0, transfer tracks130,131 of the central position A3 of thewafer24 held by thehand40 and the second joint axis A2 depict circular arcs both being convex in the forward direction X, respectively. InFIG. 11, in order to facilitate understanding, the transfer tracks130,131 of the central position A3 and the second joint axis A2 are respectively depicted by dashed lines, while correspondingimaginary lines132,133 extending in parallel with the left and right directions Y are respectively expressed by chain lines.

In this case, when the difference in the length between the first axis-to-axis distance L11 and the second axis-to-axis distance L12 is quite small, thethird link member41c can be moved in substantially parallel to the left and right directions Y. In such a manner, the first axis-to-axis distance L11 and the second axis-to-axis distance L12 may be provided with slight alteration. For example, an acceptable difference in the length between the first axis-to-axis distance L1 and the second axis-to-axis distance L12 may be set within (B−L0−E−L1) mm.

Also in the third embodiment described above, by locating the pivot axis A0 near therear wall111 and by setting the minimum rotation radius R of therobot arm41 to exceed ½ of the subtracted value (B−L0) described above and to be equal to or less than the subtracted value (B−L0), the same effect as in the first embodiment can be obtained. The length of eachlink member41a to41c of therobot arm41 and each axis-to-axis distance L11, L12 of the first to third embodiments are described by way of example, and hence may be altered. For example, the first link distance L1, second link distance L2 and third link distance L3 may not necessarily be the same.

FIG. 12 is a plan view showing a part ofsemiconductor processing equipment20C which is a fourth embodiment of the present invention. Thesemiconductor processing equipment20C of the fourth embodiment includes portions similar to those in thewafer transfer apparatus23 of the first embodiment described above. Thus such like parts are not described here, and designated by like reference numerals. In the semiconductor processing equipment20c of the fourth embodiment, thewafer transfer robot27 of thewafer transfer apparatus23 also serves as a carrier provided in thewafer processing apparatus22. In regard to the other configuration, the semiconductor processing equipment20c is the same as the first embodiment. As such, descriptions on that point are omitted here.

In the first embodiment, the carrier included in thewafer processing apparatus22 receives thewafer24 to be carried into theprocessing space30 from theinterface space29 by thewafer transfer apparatus23, and then carries the receivedwafer24 into the wafer processing position. On the other hand, in the fourth embodiment, since thewafer transfer robot27 of thewafer transfer apparatus23 can extend its operational region as shown inFIG. 12, it can transfer the wafer not only in thewafer transfer apparatus23, but can also be advanced into theprocessing space30 of thewafer processing apparatus22 so as to directly transfer thewafer24 to the wafer processing position. Accordingly, there is no need for a carrier in thewafer processing apparatus22, thus reducing the number of elements in the wafer processing equipment, thereby reducing the production cost.

In the fourth embodiment, it is preferred that therear opening121 is provided in the vicinity of the pivot axis A0 with respect to the left and right directions Y. It is also preferred that therear opening121 is formed to have a space extending longer than a distance between a first crossing point P1 that is one of two crossing points, at which an imaginary circle defined to make a circuit around the pivot axis A0, with its radius being the minimum rotation radius R of therobot27, crosses the rear-face-side wall111 and a second point P2, at which a line passing through the pivot axis A0 and extending in the forward and backward directions X crosses the rear-face-side wall111, as such the space is shaped to include both of the first crossing point P1 and the second crossing point P2. Consequently, in the case of angularly displacing thefirst link member41a about the pivot axis A0, interference of thefirst link member41a with the rear-face-side wall111 can be prevented. Thus, the first joint axis A1 set in thefirst link member41a can be located also in theprocessing space30. Accordingly, thewafer24 can be transferred to a position away from therear wall111 in the backward direction X2 in theprocessing space30.

Each of theembodiments 1 to 4 described above is illustrated by way of example, and of course may be modified within the scope of this invention. For example, while in these embodiments, thewafer transfer apparatus23 used in thewafer processing equipment20 has been described, a processing transfer apparatus for use in semiconductor processing equipment for processing substrates other than semiconductor wafers may also be included in the scope of the present invention. In this case, the substrate transfer apparatus can be generally applied to those configured to transfer each substrate from a substrate container to a substrate processing apparatus through an interface space in which an atmospheric gas is properly controlled, as well as carry the substrate from the substrate processing apparatus to the substrate container through the interface space. For example, as the substrate, semiconductor substrates and glass substrates may be mentioned. While the wafer has been described on the assumption that has a 300 mm size, the robot arm may be modified to have other link sizes in order to be applied to wafers of other sizes.

In each of the embodiments described above, while thewafer transfer apparatus23 includes thealigner56, it may includes another processing device than thealigner56. This processing device is adapted to hold each wafer in theinterface space29 and perform predetermined processes and operations. For example, as the processing device, a buffer member adapted to hold eachwafer24 in theinterface space29 or an inspection device adapted to hold the wafer in theinterface space29 and inspect it about quality and presence of defects. It should be noted that thewafer transfer apparatus23 not including the processing device, such as thealigner56, may also be included in the scope of the present invention.

In the case where it is necessary to transfer eachwafer24 over a wider region in the left and right directions in order to carry the wafer to the processing device even though only three or less FOUP openers are used, the application of this invention enables advantageous wafer transfer, even with the length B in the left and right directions of the interface space being significantly small. In this case, each position arranged in the left and right directions relative to the pivot axis A0 is determined appropriately, depending on positions of respective objects to be moved in the left and right directions. In place of using the FOUP openers, substrate container setting tables may be provided for setting substrate containers.

In this embodiment, while thefirst link member41a has been described to be able to angularly displace by 90° in one and the other directions about the pivot axis A0 relative to the reference line P0 passing through the pivot axis A0 and extending in the forward and backward directions X, the operation of thefirst link member41a is not limited to this mode. Additionally, in this embodiment, while the expressions of the forward and backward directions X, left and right directions Y and upward and downward directions Z have been used, for example, first directions, second directions and third directions or the like, which are orthogonal to one another, may be employed as alternatives.

Although the invention has been described in its preferred embodiments with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit thereof.

Claims (26)

What is claimed is:

1. A wafer transfer apparatus for transferring a wafer, comprising:

an interface space forming portion defining an interface space, the interface space forming portion having a front wall and a rear wall which are arranged at a predetermined interval in forward and backward directions, the front wall having a front opening formed therein, and the rear wall having a rear opening formed therein;

a FOUP opener configured to open and close the substrate container located adjacent to the interface space and the front opening of the interface space forming portion; and

a wafer carrying robot located in the interface space and configured to carry the wafer between the front opening and the rear opening,

wherein the wafer carrying robot includes:

a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set;

a robot arm having a proximal end and a distal end, the robot arm including a plurality of link members connected with one another in succession in a direction from the proximal end to the distal end, the proximal end being connected with the base, the distal end being provided with a robot hand for holding the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive each of the link members of the robot arm so that the link members are angularly displaced, individually, about each corresponding axis,

wherein, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<R≦B−L0), and

the minimum rotation radius R is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., R<B−L0−E).

2. The wafer transfer apparatus according toclaim 1, wherein the robot arm includes:

a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;

a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; and

a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes the robot hand at an other end of the third link member for holding the wafer,

wherein a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E).

3. The wafer transfer apparatus according toclaim 2,

wherein a first axis-to-axis distance L11 from the pivot axis to the first joint axis and a second axis-to-axis distance L12 from the first joint axis to the second joint axis are set to be equal to each other, and

wherein a second link distance L2 defined as a distance from the second joint axis to an end of the second link member, which is farthest in a direction toward the first joint axis relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

4. The wafer transfer apparatus according toclaim 3, wherein a third link distance L3 defined as a distance from the second joint axis to an end of the third link member or a portion of the wafer, which is farthest in a radial direction relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

5. The wafer transfer apparatus according toclaim 4, wherein the first link distance L1, the second link distance L2 and the third link distance L3 are respectively set to be equal to the allowable length (B−L0−E).

6. The wafer transfer apparatus according toclaim 1,

wherein the front opening includes four openings which are formed in the interface space forming portion, the four openings being arranged in left and right directions orthogonal to both the forward and backward directions and a direction of the pivot axis, and

wherein the FOUP opener includes four openers which are provided in order to open and close the four openings, respectively.

7. A substrate transfer apparatus for transferring a substrate, relative to a substrate processing apparatus for processing the substrate, comprising:

an interface space forming portion defining an interface space, the interface space forming portion having a front wall and a rear wall which are arranged in predetermined forward and backward directions at an interval, the front wall having a first transfer port formed therein, and the rear wall having a second transfer port formed therein;

an opening and closing unit configured to open and close the first transfer port of the interface space forming portion; and

a substrate carrying robot located in the interface space and configured to carry the substrate between the first transfer port and the second transfer port,

wherein the substrate carrying robot includes:

a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set;

a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;

a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis;

a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes a robot hand at an other end thereof for holding the substrate; and

a drive unit configured to drive each of the link members so that the link members are angularly displaced, individually, about each corresponding axis,

wherein the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions, and

wherein a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis, from the length B in the forward and backward directions of the interface space (i.e., B/2<L1≦B−L0), and

the first link distance L1 is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall of the interface space forming portion to the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., L1≦B−L0−E).

8. A wafer transfer apparatus for transferring a wafer, comprising:

an interface space forming portion defining an interface space, the interface space forming portion having a front wall and a rear wall which are arranged at a predetermined interval in forward and backward directions, the front wall having a front opening formed therein, and the rear wall having a rear opening formed therein;

a FOUP opener configured to open and close the substrate container located adjacent to the interface space and the front opening of the interface space forming portion; and

a wafer carrying robot located in the interface space and configured to carry the wafer between the front opening and the rear opening,

wherein the wafer carrying robot includes:

a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set;

a robot arm having a proximal end and a distal end, the robot arm including a plurality of link members connected with one another in succession in a direction from the proximal end to the distal end, the proximal end being connected with the base, the distal end being provided with a robot hand for holding the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive each of the link members of the robot arm so that the link members are angularly displaced, individually, about each corresponding axis,

wherein, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 set to be greater by a predetermined gap length Q than a radius T2 of an outer circumference of the first link member about the pivot axis (L0=T2+Q), from the length B in the forward and backward directions of the interface space (i.e., B/2<R≦B−L0), and

the minimum rotation radius R is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 set to be greater by the predetermined gap length Q than the radius T2 of an outer circumference of the first link member about the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., R<B−L0−E).

9. The wafer transfer apparatus according toclaim 8, wherein the robot arm includes:

a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;

a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis; and

a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes the robot hand at an other end of the third link member for holding the wafer,

wherein a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E) (i.e., ((B−L0−E)/2<L1≦B−L0−E).

10. The wafer transfer apparatus according toclaim 9,

wherein a first axis-to-axis distance L11 from the pivot axis to the first joint axis and a second axis-to-axis distance L12 from the first joint axis to the second joint axis are set to be equal to each other, and

wherein a second link distance L2 defined as a distance from the second joint axis to an end of the second link member, which is farthest in a direction toward the first joint axis relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

11. The wafer transfer apparatus according toclaim 10, wherein a third link distance L3 defined as a distance from the second joint axis to an end of the third link member or a portion of the wafer, which is farthest in a radial direction relative to the second joint axis, is set to exceed ½ of the allowable length (B−L0−E) and to be equal to or less than the allowable length (B−L0−E).

12. The wafer transfer apparatus according toclaim 11, wherein the first link distance L1, the second link distance L2 and the third link distance L3 are respectively set to be equal to the allowable length (B−L0−E).

13. The wafer transfer apparatus according toclaim 8,

wherein the front opening includes four openings which are formed in the interface space forming portion, the four openings being arranged in left and right directions orthogonal to both the forward and backward directions and a direction of the pivot axis, and

wherein the FOUP opener includes four openers which are provided in order to open and close the four openings, respectively.

14. A substrate transfer apparatus for transferring a substrate, relative to a substrate processing apparatus for processing the substrate, comprising:

an interface space forming portion defining an interface space, the interface space forming portion having a front wall and a rear wall which are arranged in predetermined forward and backward directions at an interval, the front wall having a first transfer port formed therein, and the rear wall having a second transfer port formed therein;

an opening and closing unit configured to open and close the first transfer port of the interface space forming portion; and

a substrate carrying robot located in the interface space and configured to carry the substrate between the first transfer port and the second transfer port,

wherein the substrate carrying robot includes:

a base which is fixed to the interface space forming portion and at which a predetermined pivot axis is set;

a first link member which is connected at its one end with the base, configured to be angularly displaced about the pivot axis, and at which a first joint axis is set in parallel to the pivot axis;

a second link member which is connected at its one end with an other end of the first link member, configured to be angularly displaced about the first joint axis, and at which a second pivot axis is set in parallel to the pivot axis;

a third link member which is connected at its one end with an other end of the second link member, configured to be angularly displaced about the second joint axis, and includes a robot hand at an other end thereof for holding the substrate; and

a drive unit configured to drive each of the link members so that the link members are angularly displaced, individually, about each corresponding axis,

wherein the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions, and

wherein a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of a length B in the forward and backward directions of the interface space, the length B corresponding to a length between the front wall and the rear wall of the interface space forming portion, and is further set to be equal to or less than a subtracted value (B−L0) to be obtained by subtracting a distance L0 set to be greater by a predetermined gap length Q than a radius T2 of an outer circumference of the first link member about the pivot axis (L0=T2+Q), from the length B in the forward and backward directions of the interface space (i.e., B/2<L1≦B−L0), and

the first link distance L1 is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 set to be greater by the predetermined gap length Q than the radius T2 of an outer circumference of the first link member about the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., L1≦B−L0−E).

15. A wafer carrying robot configured to be used for a wafer transfer apparatus, the wafer transfer apparatus having a front wall, a rear wall and a FOUP opener, the front wall having a front opening, the FOUP opener being used for opening and closing the front opening, the wafer carrying robot comprising:

a base on which a predetermined pivot axis is set;

a robot arm, the robot arm including a plurality of link members connected with one another in succession in a direction from a proximal end to a distal end, the proximal end being connected with the base, the distal end being configured to hold a robot hand that holds the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive the robot arm,

wherein, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B, the length B corresponding to a length between the front wall and the rear wall (i.e., B/2<R), and

the minimum rotation radius R is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall to the pivot axis and a length E of a robot invasion restricted region, which is determined by the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B (i.e., R≦B−L0−E).

16. A wafer carrying robot configured to be used for a wafer transfer apparatus, the wafer transfer apparatus having a front wall, a rear wall and a FOUP opener, the front wall having a front opening, the FOUP opener being used for opening and closing the front opening, the wafer carrying robot comprising:

a base on which a predetermined pivot axis is set;

a robot arm, the robot arm including a plurality of link members connected with one another in succession in a direction from a proximal end to a distal end, the proximal end being connected with the base, the distal end being configured to hold a robot hand that holds the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive the robot arm,

wherein, the wafer carrying robot configured to be used with the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions,

a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of a length B, the length B corresponding to a length between the front wall and the rear wall (i.e., B/2<L1), and

the first link distance L1 is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 in the forward and backward directions from the rear wall to the pivot axis and a length E of a robot invasion restricted region, which is determined by the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B (i.e., L1≦B−L0−E).

17. A wafer carrying robot configured to be used for a wafer transfer apparatus, the wafer transfer apparatus having a front wall, a rear wall and a FOUP opener, the front wall having a front opening, the FOUP opener being used for opening and closing the front opening, the wafer carrying robot comprising:

a base on which a predetermined pivot axis is set;

a robot arm, the robot arm including a plurality of link members connected with one another in succession in a direction from a proximal end to a distal end, the proximal end being connected with the base, the distal end being configured to hold a robot hand that holds the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive the robot arm,

wherein, in a minimum transformed state where the robot arm is transformed such that a distance defined from the pivot axis to an arm portion which is farthest in a radial direction relative to the pivot axis is minimum, a minimum rotation radius R, as the distance defined from the pivot axis to the arm portion which is the farthest in the radial direction relative to the pivot axis, is set to exceed ½ of a length B, the length B corresponding to a length between the front wall and the rear wall (i.e., B/2<R),

the minimum rotation radius R is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 set to be greater by the predetermined gap length Q than the radius T2 of an outer circumference of the first link member about the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., R≦B−L0−E), and

the predetermined gap length Q defines a space that is separate from a space defined by the length E of the robot invasion restricted region, and the predetermined gap length Q is sufficient to prevent interference that would be otherwise caused by the robot.

18. A wafer carrying robot configured to be used for a wafer transfer apparatus, the wafer transfer apparatus having a front wall, a rear wall and a FOUP opener, the front wall having a front opening, the FOUP opener being used for opening and closing the front opening, the wafer carrying robot comprising:

a base on which a predetermined pivot axis is set;

a robot arm, the robot arm including a plurality of link members connected with one another in succession in a direction from a proximal end to a distal end, the proximal end being connected with the base, the distal end being configured to hold a robot hand that holds the wafer, the robot arm being configured to be angularly displaced about the pivot axis; and

a drive unit configured to drive the robot arm,

wherein, the wafer carrying robot configured to be used with the pivot axis is located nearer to the rear wall than to the front wall or nearer to the front wall than to the rear wall in the forward and backward directions,

a first link distance L1 defined as a distance from the pivot axis to an end of the first link member, which is farthest in a radial direction toward the first joint axis relative to the pivot axis, is set to exceed ½ of a length B, the length B corresponding to a length between the front wall and the rear wall (i.e., B/2<L1),

the first link distance L1 is set to be equal to or less than an allowable length (B−L0−E) to be obtained by subtracting the distance L0 set to be greater by the predetermined gap length Q than the radius T2 of an outer circumference of the first link member about the pivot axis and a length E of a robot invasion restricted region, which is set for the FOUP opener and is measured from the front wall in the forward and backward directions toward the rear wall, from the length B in the forward and backward directions of the interface space (i.e., L1≦B−L0−E), and

the predetermined gap length Q defines a space that is separate from a space defined by the length E of the robot invasion restricted region, and the predetermined gap length Q is sufficient to prevent interference that would be otherwise caused by the robot.

19. The wafer carrying robot according to claim 15, wherein

the rear wall has a rear opening, and

the wafer carrying robot is configured to carry the wafer between the front opening and the rear opening.

20. The wafer carrying robot according to claim 15, wherein the drive unit is arranged in the robot arm.

21. The wafer carrying robot according to claim 15, wherein the front opening includes three or four openings.

22. The wafer carrying robot according to claim 15, wherein the wafer transfer apparatus has side walls, and the wafer transfer apparatus has wafer holding position in the side wall side.

23. The wafer carrying robot according to claim 15, wherein the link members include:

a first link member,

a second link member which is connected to the first link member, and

a third link member which is connected to the second link member and includes the robot hand, and

the first link member and the second link member are projected toward the front wall or the rear wall which is farther to the base when the wafer carrying robot accesses to the wafer holding position.

24. The wafer carrying robot according to claim 15,

wherein the link members include:

a first link member,

a second link member which is connected to the first link member, and

a third link member which is connected to the second link member and includes the robot hand, and

the wafer carrying robot moves one end of the third link member from near position to the front wall to the near position to the rear wall while moves the another end of the third link member from near position to the rear wall side to the near position to the front wall to rotate the robot hand.

25. The wafer carrying robot according to claim 15, wherein the proximal end of the robot arm is located near the rear wall.

26. A wafer transfer apparatus which has the wafer carrying robot according to claim 15.

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