CN115237183B - Illumination adjusting device and detection system - Google Patents

Abstract

The invention relates to the technical field of semiconductor detection, and provides an illumination adjusting device and a detection system, wherein the illumination adjusting device comprises a plurality of groups of induction groups, a position sensor, an actuator, a light intensity detector and an adjusting processor; the induction group comprises a cross rod, a vertical rod and an induction deformation end; the light intensity detector is used for detecting the light intensity radiated by the induction deformation end; driving the position of the induction group according to the shape change of the induction deformation end and the position change of the induction group; the detection system comprises a multi-wavelength laser module, a measurement illumination module, a vortex reference module, a focusing optical module, an image acquisition module, a data processing module, an external output module and a light intensity adjusting module; the illumination adjusting device is simple in structure, each group of sensing groups is independently controlled, the uniformity of the illumination intensity of the gap light transmission adjustment is realized through position adjustment, the imaging or image acquisition quality of the detection system is improved, the illumination adjusting device is suitable for detection of wafers or light masks with multiple specifications, and the illumination adjusting device is convenient to popularize and apply in the detection field of semiconductors such as wafers or light masks.

Description

Illumination adjusting device and detection system

Technical Field

The invention belongs to the technical field of semiconductor detection, and particularly relates to an illumination adjusting device and a detection system.

Background

In the manufacturing and inspection processes of semiconductor wafers and photomasks (masks), an illumination light source for inspection is commonly used, however, the illumination or imaging light beam of the conventional illumination light source is often not uniform in the light path, which has adverse effects on the transmission or reflection process of key optical elements such as a reflecting mirror, a dichroic mirror, a wafer or a photomask, and leads to the reduction of the inspection quality of the imaging. Therefore, there is a need for a detection system that provides controlled adjustment of the uniformity of the illumination beam (e.g., the illumination intensity across the beam) at each stage of the optical path or at each process node.

Disclosure of Invention

In order to overcome the disadvantages of the prior art, the present invention provides an illumination adjusting apparatus and a detection system, which can solve the above problems.

An illumination adjusting device comprises a plurality of groups of induction groups, a position sensor, an actuator, a light intensity detector and an adjusting processor; the induction group comprises a cross rod, a vertical rod and an induction deformation end; the bottom of the vertical rod is connected to the outer end of the cross rod, the induction deformation end is arranged at the top of the vertical rod, the position sensor is arranged on the bottom surface of the cross rod close to the outer end, the actuator is arranged on the bottom surface of the cross rod close to the inner end, and the light intensity detector is arranged corresponding to the induction deformation end; the induction deformation end of the induction group is parallel or vertical to the cross bar, and the parallel induction group or the vertical induction group is used independently or in combination; the position sensor, the actuator, the light intensity detector and the adjusting processor are in telecommunication connection; the light intensity detector is used for detecting the light intensity radiated by the induction deformation end; the position sensor is used for monitoring the position changes of the induction deformation end and the cross rod; and the adjusting processor corresponding to each group of induction groups is used for receiving the information of the light intensity detector and the position sensor to determine the shape change of the induction deformation end and the position change of the induction groups and sending a driving signal to the actuator so as to adjust the positions of the induction groups to realize the illumination uniformity adjustment of the illumination light source.

Furthermore, the induction deformation end of the induction group adopts a heat-sensitive or photosensitive component, and one or more reference deformation marks are arranged on the bottom surface of the induction deformation end.

Furthermore, a specular reflection layer is arranged on the peripheral surface of the induction deformation end of the induction group, the specular reflection layer is of a single-layer or multi-layer structure, and the reference deformation mark is arranged on the specular reflection layer.

Furthermore, the adjustment position of the induction group comprises the outward extension distance of the induction deformation end of the induction group and the spacing distance between adjacent induction groups.

Furthermore, a plurality of groups of induction groups, position sensors and actuators are arranged in one adjusting frame.

The invention also provides a detection system with illumination adjustment, which comprises a multi-wavelength laser module, a measurement illumination module, a vortex reference module, a focusing optical module, an image acquisition module, a data processing module, an external output module and a light intensity adjustment module; the light intensity adjusting module adopts the illumination adjusting device; the multi-wavelength laser module is used for providing lasers with various wavelengths; the measurement illumination module and the vortex reference module are arranged at the downstream of the multi-wavelength laser module to form two optical path branches: the measuring illumination module is used for providing part of laser with various wavelengths as measuring light to a measured sample after the measuring light passes through the focusing optical module and is used for collecting information of the measured sample; the vortex reference module carries out vortex modulation on the laser with multiple wavelengths of the rest part, and the formed multi-path single-wavelength vortex optical rotation is combined and then serves as reference light to be provided for the image acquisition module; the light intensity adjusting module is arranged at the emergent end of the multi-wavelength laser module and/or between the measuring illumination module and the focusing optical module and is used for detecting the emergent light intensity and adjusting the illumination uniformity; the focusing optical module is arranged at the downstream of the optical path of the measuring illumination module and used for providing the measuring light of the measuring illumination module for the measured sample and then reflecting the measuring light to form the surface of the measured sample and sending the surface of the measured sample to the image acquisition module through the detection optical path; the image acquisition module respectively detects and collects reference light and measuring light with measured sample surface measuring information according to the wavelength; the data processing module is used for acquiring the measurement information of the image acquisition module and calculating the height information of the measured sample; and the external output module is used for externally outputting and displaying the height information of the measured sample calculated by the data processing module.

Furthermore, the multi-wavelength laser module comprises a multi-wavelength laser, a collimation beam expander, a first polaroid and a first reflector which are sequentially arranged; the collimating and beam expanding device is used for collimating and expanding the laser with various wavelengths emitted by the multi-wavelength laser; the first polaroid modulates the laser with multiple wavelengths after collimation and beam expansion into linear polarized light; the first reflector is used for changing an emergent light path; the light intensity adjusting module is disposed between the first polarizer and the first mirror.

Compared with the prior art, the invention has the beneficial effects that: the illumination adjusting device is simple in structure, each group of sensing groups is independently controlled, the uniformity of the illumination intensity of the gap light transmission adjustment is realized through position adjustment, the imaging or image acquisition quality of the detection system is improved, the illumination adjusting device is suitable for detection of wafers or light shields with multiple specifications, and the illumination adjusting device is convenient to popularize and apply in the field of semiconductor detection.

Drawings

FIG. 1 is a schematic view of an embodiment of the illumination adjustment apparatus according to the present invention;

FIG. 2 is a schematic view of an induction set and accessories of the embodiment of FIG. 1;

FIG. 3 is a schematic view of another embodiment of the illumination adjustment apparatus according to the present invention;

FIG. 4 is a schematic view of an inductive bank and accessories of the embodiment of FIG. 3;

FIG. 5 is a schematic diagram of a detection system with illumination adjustment.

In the figure, the position of the upper end of the main shaft,

1. a cross bar; 2. erecting a rod; 3. sensing a deformation end; 4. a position sensor; 5. an actuator; 6. a light intensity detector; 7. an adjusting frame;

10. a multi-wavelength laser module; 11. a multi-wavelength laser; 12. a collimated beam expander; 13. a first polarizing plate; 14. a first reflector;

20. a measurement illumination module; 21. a beam splitter; 22. a reflective polarizer; 23. a quarter wave plate;

30. a vortex reference module;

40. a focusing optical module;

50. an image acquisition module;

60. a data processing module;

70. an external output module;

80. a light extinction module;

90. and a light intensity adjusting module.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Illumination adjusting device

An illumination adjustment device, see fig. 1-4, comprising a plurality of sets of sensing sets, aposition sensor 4, anactuator 5, a light intensity detector 6 and an adjustment processor.

Wherein, the response group includes horizontal pole 1, pole setting 2 andresponse deformation end 3. The bottom of pole setting 2 is connected to the outer tip of horizontal pole 1, andresponse deformation end 3 sets up at the top of pole setting 2, andposition sensor 4 sets up on the bottom surface that horizontal pole 1 is close to the outer end, andactuator 5 sets up on horizontal pole 1 is close to the bottom surface of inner, and light intensity detector 6 sets up with the setting thatresponse deformation end 3 corresponds.

The induction deformation ends 3 of the induction groups are arranged in parallel (see figures 1 and 2) or perpendicular (see figures 3 and 4) with the cross bar 1, and the parallel induction groups or the perpendicular induction groups are used singly or in combination.

Theposition sensor 4, theactuator 5, the light intensity detector 6 and the adjustment processor are in electrical communication. The light intensity detector 6 is used for detecting the light intensity radiated by theinduction deformation end 3. Theposition sensor 4 is used for monitoring the position change of theinduction deformation end 3 and the cross rod 1. The adjusting processor corresponding to each group of sensing groups is used for receiving the information of the light intensity detector 6 and theposition sensor 4 to determine the shape change of thesensing deformation end 3 and the position change of the sensing groups, and sending a driving signal to theactuator 5, so that the position of the sensing groups is adjusted to realize the illumination uniformity adjustment of the illumination light source.

Wherein, theinduction deformation end 3 of the induction group adopts a heat-sensitive or photosensitive component, and one or more reference deformation marks are arranged on the bottom surface of theinduction deformation end 3.

Furthermore, a mirror reflection layer is arranged on the outer peripheral surface of theinduction deformation end 3 of the induction group, the mirror reflection layer is of a single-layer or multi-layer structure, and the reference deformation mark is arranged on the mirror reflection layer. The mirror reflection layer is made of molybdenum material layer or alternating layers of molybdenum and silicon material.

Wherein, the adjusting position of the induction group comprises the outward extension distance of theinduction deformation end 3 of the induction group and the spacing distance between the adjacent induction groups.

The form of theactuator 5 includes electromagnetic, electric and the like, and can realize the front-back and left-right plane movement of the cross rod 1 fixedly connected with the upper part of the actuator.

Referring to fig. 1 or 3, a plurality of sensing sets,position sensors 4,actuators 5 are disposed in anadjustment frame 7.

It should be further noted that the illumination adjusting device may be arranged in parallel with the cross bar 1 as the induction deformation ends 3 of the multiple induction sets shown in fig. 1; at this time, theactuator 5 is required to drive the cross bar 1 to move forwards, backwards, leftwards or rightwards according to the driving signal of the adjusting processor, and the extension length of theinduction deformation end 3 or the distance between the cross bars 1 is adjusted, so that the light intensity uniformity of the illumination adjusting device is integrally adjusted.

The arrangement of the illumination adjusting device can also be as shown in the figure 3 that the induction deformation ends 3 of a plurality of groups of induction groups are arranged vertically to the cross rod 1; theactuator 5 drives the cross rod 1 to move forwards, backwards, leftwards or rightwards according to the driving signal of the adjusting processor, and the extending length of theinduction deformation end 3 or the distance between the cross rods 1 is adjusted, so that the light intensity uniformity of the illumination adjusting device is integrally adjusted.

Of course, the illumination adjusting device can also adopt the parallel and vertical arrangement, the parallel induction deformation ends 3 and the vertical induction deformation ends 3 are crossed and arranged in a grid shape, and the light intensity uniformity of the illumination adjusting device is adjusted through the light transmission gaps of the adjusting induction groups of theactuator 5.

The parallel sensing groups or the vertical sensing groups are used singly or in combination.

Detection system

A detection system with illumination adjustment, see FIG. 5, includes amulti-wavelength laser module 10, ameasurement illumination module 20, avortex reference module 30, a focusingoptical module 40, animage acquisition module 50, adata processing module 60, anexternal output module 70, and a lightintensity adjustment module 90. Wherein, the lightintensity adjusting module 90 adopts the aforementioned illumination adjusting device. In a whole, the light path system comprises a laser light source, illumination adjustment, a vortex modulation light path, interference measurement and the like to form a vortex-based detection scheme.

Themulti-wavelength laser module 10 is used for providing laser with multiple wavelengths. Themeasurement illumination module 20 and thevortex reference module 30 are disposed downstream of themulti-wavelength laser module 10, forming two optical path branches: themeasurement illumination module 20 is configured to provide a part of laser with multiple wavelengths as measurement light to the sample to be measured after passing through the focusingoptical module 40, and is configured to collect information of the sample to be measured. Thevortex reference module 30 performs vortex modulation on the remaining laser beams with multiple wavelengths, and the formed multi-path single-wavelength vortex optical rotations are combined and then provided to theimage acquisition module 50 as reference light. The lightintensity adjusting module 90 is disposed at the exit end of themulti-wavelength laser module 10 and/or between the measuringillumination module 20 and the focusingoptical module 40, and is used for detecting the exit light intensity and adjusting the illumination uniformity.

The focusingoptical module 40 is disposed downstream of the measuringillumination module 20 in the optical path, and is configured to provide the measuring light from the measuringillumination module 20 to the sample to be measured, and then reflect the measuring light to form a surface of the sample to be measured, and transmit the surface of the sample to theimage acquisition module 50 through the detection optical path.

Theimage acquisition module 50 detects and collects the reference light and the measurement light with the measurement information of the surface of the sample to be measured according to the wavelength.

Thedata processing module 60 is used for collecting the measurement information of theimage collecting module 50 and calculating the height information of the measured sample.

Theexternal output module 70 externally outputs and displays the height information of the measured sample calculated by thedata processing module 60.

Themulti-wavelength laser module 10 includes amulti-wavelength laser 11, acollimating beam expander 12, afirst polarizer 13, and afirst reflector 14, which are sequentially disposed. The collimatedbeam expander 12 is configured to collimate and expand the laser beams with multiple wavelengths emitted by themulti-wavelength laser 11. The firstpolarizing plate 13 modulates the collimated and spread laser beams of the plurality of wavelengths into linearly polarized light. Thefirst reflector 14 is used for changing an emergent light path, and the occupied space of the system is reduced. In one example, thefirst mirror 14 is arranged normal to the incident light at 45 °. The lightintensity adjusting module 90 is disposed between thefirst polarizer 13 and the first reflectingmirror 14. Finally, themulti-wavelength laser module 10 provides multi-wavelength laser light (λ 1, λ 2, \8230; λ i, i is a positive integer ≧ 2) modulated via linear polarization.

Wherein, themeasurement illumination module 20 and thevortex reference module 30 are arranged at the downstream of themulti-wavelength laser module 10, and two optical path branches are formed: themeasurement illumination module 20 is configured to provide part of laser with multiple wavelengths as measurement light to the measured sample through the focusingoptical module 40, and is configured to collect information of the measured sample; thevortex reference module 30 performs vortex modulation on the remaining laser beams with multiple wavelengths, and the formed multi-path single-wavelength vortex optical rotations are combined and then provided to theimage acquisition module 50 as reference light.

Specifically, themeasurement illumination module 20 includes a beam splitter 21, areflective polarizer 22 and aquarter wave plate 23, which are sequentially arranged. The spectroscope 21 is configured to transmit a part of the multi-wavelength laser as measurement light; thereflective polarizer 22 and the quarter-wave plate 23 are used to transmit the measurement light passing through the beam splitter 21 to the focusingoptical module 40 in sequence.

Specifically, thevortex reference module 30 includes a half-wave plate HWP, a first dichroic mirror DM1, a first vortex phase plate VPP1, a second mirror M2, a second vortex phase plate VPP2, a third mirror M3, and a second dichroic mirror DM2. The half-wave plate HWP is used for rotating the polarization direction of the laser with multiple wavelengths reflected by the spectroscope 21 by 90 degrees; the first dichroic mirror DM1 is configured to split the laser beams with multiple wavelengths that have passed through the dichroic mirror 21 into two single-wavelength gaussian beams.

Furthermore, the two single-wavelength gaussian beams pass through the first vortex phase plate VPP1 and the second vortex phase plate VPP2 respectively and then become vortex beams with a charge value l = 1.

The second reflector M2 and the third reflector M3 are used for redirecting a single-wavelength Gaussian beam before and after passing through the second vortex phase plate VPP 2.

Further, the second dichroic mirror DM2 is configured to combine the two vortex light beams with a charge value l =1 as reference light, and transmit the reference light after being completely transmitted by thereflective polarizer 22 to theimage capturing module 50.

The focusingoptical module 40 is disposed downstream of themeasurement illumination module 20 in the optical path, and is configured to provide the measurement light of themeasurement illumination module 20 to the sample to be measured, and then reflect the measurement light to form a surface of the sample to be measured, and send the surface of the sample to theimage acquisition module 50 through the detection optical path.

Specifically, the focusingoptical module 40 employs an afocal optical system or a telescopic system. Depending on the difference in measurement/monitoring requirements, different configurations may be chosen, such as: 1) Homogeneous media or free space; 2) A microscopic imaging system consisting of a microscopic cylindrical lens and a microscopic objective; 3) A beam reduction or expansion system.

Theimage acquisition module 50 detects and collects reference light and measuring light with measured sample surface measurement information according to wavelength; theimage acquisition module 50 adopts an area array detector or adopts a plurality of detector array modules.

When a plurality of detector array modules are employed, each detector array module includes a plurality of detector arrays (SA 1, SA2, \8230; SAj, j is a positive integer ≧ 2, see for example FIG. 5 where j is 2, i.e., two detector arrays are employed), a third dichroic mirror DM3, and a second polarizer P2. The second polarizer P2 is used to modulate the reference light transmitted through thereflective polarizer 22 and the reflected measurement light; the third dichroic mirror DM3 is configured to split the multi-wavelength light beam modulated by the second polarizer P2 into single light beams with multiple wavelengths, and receive and collect the single light beams by a corresponding detector array.

Further, each detector array comprises a plurality of light intensity detectors PD1, PD2 and PD3 \8230whichare uniformly arranged along the circumferential direction by taking the center of the interference pattern as an axis, wherein the \8230andthe PDm is a positive integer more than or equal to 3.

In one example, the light intensity detector is in the form of, but not limited to, a photodiode or the like.

Theexternal output module 70 externally outputs and displays the height information of the measured sample calculated by thedata processing module 60.

The detection system further comprises anextinction module 80, which is arranged at the spectroscope 21 and used for eliminating stray light emitted out through the spectroscope 21 and improving the signal-to-noise ratio of the system.

Theextinction module 80 may employ a variety of extinction schemes, including but not limited to the following forms: 1) A light-absorbing surface angled from the optical axis; 2) The emergent beam is reflected outside the system.

According to different application requirements, the measurement system can select various configurations: single/multiple wavelength, expanded/contracted beam, number of detectors, etc.

The scheme integrally utilizes the spatial phase distribution characteristic of the vortex light beam to convert the height information into a rotation angle of an interference pattern around an optical axis, and a plurality of high-speed point light intensity detectors are used for forming an interference measurement module, so that the height information of the measured sample is detected in real time; and the uniformity of the illumination intensity is adjusted in the period, so that the imaging or measuring quality is improved.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (6)

1. An illumination adjustment device, characterized in that:

comprises a plurality of groups of induction groups, a position sensor (4), an actuator (5), a light intensity detector (6) and an adjusting processor;

the induction group comprises a cross rod (1), a vertical rod (2) and an induction deformation end (3); the bottom of the vertical rod (2) is connected to the outer end of the cross rod (1), the induction deformation end (3) is arranged at the top of the vertical rod (2), the position sensor (4) is arranged on the bottom surface, close to the outer end, of the cross rod (1), the actuator (5) is arranged on the bottom surface, close to the inner end, of the cross rod (1), and the light intensity detector (6) is arranged corresponding to the induction deformation end (3);

the induction deformation ends (3) of the induction groups are parallel or vertical to the cross rod (1), or the induction deformation ends (3) parallel to the cross rod and the induction deformation ends (3) vertical to the cross rod are crossed and arranged in a grid shape;

the position sensor (4), the actuator (5), the light intensity detector (6) and the adjusting processor are in telecommunication connection; the light intensity detector (6) is used for detecting the light intensity radiated by the induction deformation end (3); the position sensor (4) is used for monitoring the position changes of the induction deformation end (3) and the cross rod (1); the adjusting processor corresponding to each group of sensing groups is used for receiving information of the light intensity detector (6) and the position sensor (4) to determine shape change of the sensing deformation end (3) and position change of the sensing groups, and sending a driving signal to the actuator (5) so as to adjust the positions of the sensing groups to realize illumination uniformity adjustment of the illumination light source; the adjusting position of the induction group comprises the outward extending distance of the induction deformation end (3) of the induction group and the spacing distance between the adjacent induction groups.

2. A lighting adjustment device as claimed in claim 1, characterized in that:

the induction deformation end (3) of the induction group adopts a thermosensitive or photosensitive component, and one or more reference deformation marks are arranged on the bottom surface of the induction deformation end (3).

3. A lighting adjustment device according to claim 2, characterized in that:

the periphery of the induction deformation end (3) of the induction group is provided with a specular reflection layer, the specular reflection layer is of a single-layer or multi-layer structure, and the reference deformation mark is arranged on the specular reflection layer.

4. A lighting adjustment device as claimed in claim 1, characterized in that:

the multiple groups of induction groups, the position sensor (4) and the actuator (5) are arranged in an adjusting frame (7).

5. A detection system with illumination adjustment, characterized by:

the detection system comprises a multi-wavelength laser module (10), a measuring illumination module (20), a vortex reference module (30), a focusing optical module (40), an image acquisition module (50), a data processing module (60), an external output module (70) and a light intensity adjusting module (90); the light intensity adjusting module (90) adopts the illumination adjusting device of any one of claims 1 to 4;

the multi-wavelength laser module (10) is used for providing lasers with multiple wavelengths;

the measurement illumination module (20) and the vortex reference module (30) are arranged at the downstream of the multi-wavelength laser module (10) to form two optical path branches: the measuring illumination module (20) is used for providing part of laser with various wavelengths as measuring light to a measured sample after passing through the focusing optical module (40) and is used for collecting information of the measured sample; the vortex reference module (30) performs vortex modulation on the remaining laser with multiple wavelengths, and the formed multi-path single-wavelength vortex optical rotation is combined and then serves as reference light to be provided for the image acquisition module (50); the light intensity adjusting module (90) is arranged at the emergent end of the multi-wavelength laser module (10) and/or between the measuring illumination module (20) and the focusing optical module (40) and is used for detecting the emergent light intensity and adjusting the illumination uniformity;

the focusing optical module (40) is arranged on the downstream of the optical path of the measuring illumination module (20) and is used for providing the measuring light of the measuring illumination module (20) to the measured sample and reflecting the measuring light to form the surface of the measured sample and sending the surface of the measured sample to the image acquisition module (50) through a detection optical path;

the image acquisition module (50) respectively detects and collects reference light and measuring light with measured sample surface measuring information according to the wavelength;

the data processing module (60) is used for acquiring the measurement information of the image acquisition module (50) and calculating the height information of the measured sample;

the external output module (70) externally outputs and displays the height information of the measured sample calculated by the data processing module (60).

6. The detection system with illumination adjustment according to claim 5, characterized in that:

the multi-wavelength laser module (10) comprises a multi-wavelength laser (11), a collimation beam expander (12), a first polaroid (13) and a first reflector (14) which are sequentially arranged;

the collimation beam expander (12) is used for collimating and expanding laser with multiple wavelengths emitted by the multi-wavelength laser (11); the first polaroid (13) modulates the laser with multiple wavelengths after collimation and beam expansion into linear polarized light; the first reflector (14) is used for changing an emergent light path; the light intensity adjusting module (90) is arranged between the first polarizer (13) and the first reflector (14).

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