CN114481324A - Semiconductor processing apparatus and heating method for target growth - Google Patents

Abstract

The application discloses a semiconductor processing device and a heating method for target growth, which can optimize the quality of a prepared target and reduce defects in the target. The semiconductor processing apparatus includes: a reaction chamber including a first end and a second end sequentially arranged in an axial direction of the reaction chamber, and a target formed at the first end; a heating module comprising: a first heater disposed above the first end and having at least a heat radiation surface distributed along a first growth direction of the target; a second heater disposed at the first end side surface and having at least a heat radiation surface distributed along a second growth direction of the target; a third heater disposed below the second end and having at least a heat radiation surface distributed along a second growth direction of the target; a fourth heater disposed at the second end side surface and having at least a heat radiation surface distributed along the first growth direction of the target; the heating powers of the first heater, the second heater, the third heater and the fourth heater are mutually independent.

Description

Semiconductor processing apparatus and heating method for target growth

Technical Field

The application relates to the field of target growth, in particular to semiconductor processing equipment and a heating method for target growth.

Background

For the preparation of the target, Physical Vapor Transport (PVT) or the like can be used. For example, when silicon carbide (SiC) is produced, SiC crystals having high purity can be obtained by the PVT method.

SiC belongs to a third-generation semiconductor material, has the characteristics of wide forbidden band, high thermal conductivity, high critical breakdown field, high electron saturation drift rate and the like, is a hot material for preparing high-temperature, high-frequency and high-power devices, and has wide prospects in the fields of electric automobiles, high-speed rails, communication, aerospace and the like.

In the prior art, the target prepared by adopting a PVT method and the like is not high in quality, is easy to have defects of dislocation, stacking fault and the like, and is not beneficial to subsequent use.

Disclosure of Invention

In view of the above, the present application provides a semiconductor processing apparatus and a heating method for target growth, which can optimize the quality of the prepared target and reduce the defects of the target.

The present application provides a semiconductor processing apparatus for preparing an object, comprising: a reaction chamber including a first end and a second end sequentially arranged in an axial direction of the reaction chamber, and the target being formed at the first end; a heating module comprising: a first heater disposed above the first end and having at least a heat radiation surface distributed along a first growth direction of the target; the second heater is arranged on the side surface of the first end and at least provided with a heat radiation surface distributed along the second growth direction of the target object, and the top of the second heater is higher than the plane where the first end of the reaction chamber is located or is flush with the plane where the first end of the reaction chamber is located; the third heater is arranged below the second end and at least provided with a heat radiation surface distributed along the second growth direction of the target object, and the bottom of the third heater is lower than the plane where the second end of the reaction chamber is located or is flush with the plane where the second end of the reaction chamber is located; a fourth heater provided at the second end side surface and having at least a heat radiation surface distributed along the first growth direction of the target; the heating powers of the first heater, the second heater, the third heater and the fourth heater are mutually independent.

Optionally, an outer contour shape of a projection of the heat radiation surface of the first heater on a plane where the first end is located is matched with a shape of the first end, and the projection of the heat radiation surface of the first heater on the plane where the first end is located at least partially covers the first end of the reaction chamber; the projection of the heat radiation surface of the fourth heater on the plane of the second end at least partially covers the second end of the reaction chamber.

Optionally, the reaction chamber includes a cylindrical cavity and a circular top cover, the first heater and the fourth heater are both in a disc shape, the second heater and the third heater are both in a cylindrical shape, the cavity is surrounded by the second heater and the third heater, and the first heater and the fourth heater are respectively disposed above the top cover and below the bottom of the cavity.

Optionally, the length of the heat radiation surface of the second heater in the axial direction of the reaction chamber is smaller than the length of the heat radiation surface of the third heater in the axial direction of the reaction chamber.

Optionally, a distance between the heat radiation surface of the first heater and the first end is greater than or equal to a distance between the heat radiation surface of the fourth heater and the second end.

Optionally, a gap exists between the second heater and the third heater, and the size of the gap ranges from 15mm to 30 mm.

Optionally, the first heater is further provided with a first through hole, the first through hole penetrates through the first heater and exposes the first end of the reaction chamber, and/or: the fourth heater is provided with a second through hole which penetrates through the fourth heater and exposes the second end of the reaction chamber.

Optionally, the heating system further comprises a power control module connected to the heating modules and configured to control the heating power of each heater in the heating modules respectively.

The application provides a heating method for target growth, which uses the semiconductor processing equipment to realize heating, wherein the target is grown at a first end of a reaction chamber, and the heating method comprises the following steps: controlling a temperature distribution of the first end of the reaction chamber in a first growth direction of the target by the first heater; controlling the temperature distribution of the side surface of the first end of the reaction chamber in the second growth direction of the target object through the second heater; controlling the temperature distribution of the side surface of the second end of the reaction chamber in the second growth direction through the third heater; and controlling the temperature distribution of the second end of the reaction chamber in the first growth direction through the fourth heater.

Optionally, the heating power ratio of the first heater, the second heater, the third heater and the fourth heater is (0-3): (0-4): (0-5): (5-8).

According to the semiconductor processing equipment and the heating method for the growth of the target, the target can be prepared by using the heating module, and the first heater is arranged above the first end where the target is located, so that the temperature field in the first growth direction of the target can be controlled by the first heater, the isothermal line of the growth interface of the target can be adjusted as required, the growth interface of the flat or slightly convex target is obtained, and the quality of the finally obtained target is improved.

In addition, the second heater and the third heater are arranged around the first end, the second heater and the third heater at least have heat radiation surfaces distributed along the second growth direction of the target object, and the heating power of the second heater and the heating power of the third heater can be independently controlled, so that the temperature gradient of the reaction chamber in the second growth direction can be controlled through the second heater and the third heater, the reaction gas transportation speed is increased, and the growth speed of the target object is increased.

And because the fourth heater is arranged below the second end, the temperature of the second end can be controlled by the fourth heater, and sufficient temperature is provided for the reaction material placed at the second end, so that the growth speed of the target object is accelerated.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a semiconductor processing apparatus according to an embodiment of the present application.

FIG. 2 is a schematic top view of a first heater of a semiconductor processing apparatus according to an embodiment of the present application.

FIG. 3 is a schematic view of an isotherm within a reaction chamber of a semiconductor processing apparatus according to an embodiment of the present application.

FIG. 4 is a flow chart illustrating steps of a heating method for growing a target according to an embodiment of the present disclosure.

Detailed Description

It has been found that the above problems occur mainly because it is difficult to provide a controllable temperature field for the reaction environment in the conventional PVT technique, and the shape of the growth interface of the target is similar to the isotherm of the interface, and if the isotherm at the growth interface is not straight, the growth interface of the target is uneven, resulting in defects.

The isothermal line comprises three conditions, namely a convex isothermal line with a downward center and a low temperature at the center of the bulge, and a concave isothermal line with an upward center and a high temperature at the center of the bulge. A convex isotherm produces a convex target interface, a concave isotherm produces a concave target interface, and a flat isotherm produces a flat target interface. The concave or convex interface morphology can cause problems in the quality of the target, leading to defects.

In particular, the convex or concave isotherms tend to induce thermoelastic stresses during target growth, resulting in stress and thermal stress related target defects such as stacking faults, polytype and basal plane dislocations, and the like. The flat isotherm suppresses thermal stress of the target due to temperature uniformity in the first growth direction of the growth interface, thereby reducing target defects. Therefore, to grow a high quality target, it is necessary to provide a suitable temperature field at the growth interface of the target, and the temperature difference should have a relatively flat isotherm at the growth interface.

Therefore, in order to solve the above problems, the present application provides a semiconductor processing apparatus and a heating method for target growth, which can provide a controllable temperature field for a target preparation process, so as to form a flat or slightly convex isotherm on a target growth interface, avoid generating a concave or excessively convex temperature field, prepare a high-quality target, and obtain a flat or slightly convex target interface, thereby improving the preparation quality of the target and reducing the probability of target defects.

The following will further describe the semiconductor processing apparatus and the heating method for growing the object, with reference to the drawings and the embodiments.

Fig. 1 is a schematic structural diagram of a semiconductor processing apparatus according to an embodiment of the present application.

The present application provides in a first aspect a semiconductor processing apparatus for preparing atarget 22, comprising: areaction chamber 20 including afirst end 40 and asecond end 41 sequentially arranged in an axial direction of thereaction chamber 20, and atarget 22 formed at thefirst end 40; a heating module including afirst heater 25 disposed above thefirst end 40 and having at least a heat radiation surface distributed along a first growth direction of thetarget 22; asecond heater 24 disposed at a side of thefirst end 40 and having at least a heat radiation surface distributed along a second growth direction of thetarget 22, wherein a top of thesecond heater 24 is higher than a plane of thefirst end 40 of thereaction chamber 20 or is flush with the plane of thefirst end 40 of the reaction chamber; athird heater 26 disposed below thesecond end 41 and having at least a heat radiation surface distributed along the second growth direction of thetarget 22, wherein the bottom of thethird heater 26 is lower than the plane of thesecond end 41 of thereaction chamber 20 or is flush with the plane of thesecond end 41 of thereaction chamber 20; afourth heater 27 disposed on the side of thesecond end 41 and having at least a heat radiation surface distributed along the first growth direction of thetarget 22; the heating powers of thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 are independent of each other.

Since thefirst heater 25 is disposed above thefirst end 40 where thetarget 22 is located, the temperature field in the first growth direction of thetarget 22 can be controlled by thefirst heater 25, the isotherm of the growth interface of thetarget 22 can be adjusted as needed, a flat or slightly convex growth interface of thetarget 22 is obtained, and the quality of the obtainedtarget 22 is improved.

Moreover, since thesecond heater 24 and thethird heater 26 are disposed around thefirst end 40, thesecond heater 24 and thethird heater 26 at least have heat radiation surfaces distributed along the second growth direction of thetarget 22, and the heating powers of thesecond heater 24 and thethird heater 26 can be independently controlled, the temperature gradient of thereaction chamber 20 in the second growth direction can be controlled by thesecond heater 24 and thethird heater 26, so as to accelerate the reaction gas transportation speed and improve the growth speed of thetarget 22.

Moreover, since thefourth heater 27 is disposed below thesecond end 41, the temperature of thesecond end 41 can be controlled by thefourth heater 27 to provide a sufficient temperature for the reaction material placed at thesecond end 41, thereby accelerating the growth rate of thetarget 22.

Moreover, due to the more controllable temperature field environment, as the radial dimensions of the induction coil and thereaction chamber 20 increase, the temperature distribution in the first growth direction of the growth interface of thetarget 22 can also be kept uniform, which is beneficial for preparing high-quality large-diameter targets 22, such as large-diameter targets 22 with radial dimensions of more than 150 mm.

In some embodiments, thereaction chamber 20 includes acylindrical cavity 60 and acircular top cover 50. Acircular top cover 50 is disposed on the top of thecylindrical cavity 60 to form a closedreaction chamber 20 together with thecavity 60, and thetarget 22 is formed on a side surface of thetop cover 50 facing the inside of thecavity 60.

In some embodiments, the height of thereaction chamber 20 is about 200mm to 400mm, i.e., the overall height of thecylindrical chamber 60 and thecircular lid 50 is about 200mm to 400mm, and the radial dimension of thecylindrical chamber 60 is configured to be consistent with the overall height. In practice, the specific shape and size of thereaction chamber 20 may also be set as desired.

In some embodiments, thereaction chamber 20 includes a crucible including a crucible body having a cylindrical shape corresponding to thecavity 60 of thereaction chamber 20 and a crucible cover having a circular shape corresponding to thetop cover 50 of thereaction chamber 20.

The crucible cover is arranged on the top of the crucible body when in use. Thefirst heater 25 is located above the crucible cover, thefourth heater 27 is located below the bottom of the crucible body, and thesecond heater 24 and thethird heater 26 are disposed around the side of the crucible and are sequentially distributed on the upper side of the crucible and the lower side of the crucible.

In some embodiments, the crucible is made of a material comprising at least one of graphite, tantalum, tungsten, refractory compounds, tantalum carbide, niobium carbide.

Illustratively, the crucible is a graphite crucible.

In physical vapor deposition (PVT) using thereaction chamber 20 to form thetarget 22, thereaction material 30 is stacked at thesecond end 41 of thereaction chamber 20, theseed holder 21 is provided at thefirst end 40 of thereaction chamber 20, and theseed 22 is provided on the surface of theseed holder 21 to form thetarget 22.

During the reaction, the reaction gas formed by sublimation of thereaction material 30 rises to the upper half of the reaction chamber, i.e., the first end, and is crystallized on theseed crystal 22 to form thetarget 22.

In some embodiments, thetarget 22 is a SiC crystal and the reactant material, including a silicon carbide frit, is deposited at thesecond end 41 of thereaction chamber 20. Si and Si formed by sublimating silicon carbide powder are distributed in the reaction gas environment₂C、SiC₂And (3) the gas phase components. Si, Si₂C、SiC₂The isogas phase components are transported to the surface of theseed crystal 22 arranged on theseed crystal holder 21 of thefirst end 40, and the SiC crystal growth is carried out on the surface of theseed crystal 22 by crystallization.

Illustratively, the silicon carbide powder is 6H-SiC polycrystalline grains having a grain size of 0.5mm to 2 mm.

The growth interface of thetarget 22 is perpendicular to the axial direction of thereaction chamber 20, and thetarget 22 can grow in the axial direction of thereaction chamber 20 and can also grow in a direction perpendicular to the axial direction of thereaction chamber 20, the first growth direction being perpendicular to the axial direction of thereaction chamber 20, and the second growth direction being parallel to the axial direction of thereaction chamber 20.

The first growth direction and the second growth direction may be set according to the production environment and production conditions of thespecific object 22.

In some embodiments, thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 are disposed coaxially with thereaction chamber 20, and thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 and thereaction chamber 20 are surrounded by thermal insulators, which are not drawn in the drawings. In fact, thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 may be provided in the form and in the positional relationship with respect to thereaction chamber 20 as needed.

In some embodiments, the number of heaters disposed around the side of thereaction chamber 20 between thefirst end 40 and thesecond end 41 of thereaction chamber 20 is not limited to two, and may be more, such as four, five, or six, and each heater is disposed in concentric rings and sequentially distributed along the axial direction of thereaction chamber 20. In practice, the number of heaters positioned between thefirst end 40 and thesecond end 41 of thereaction chamber 20 may be set as desired.

In some embodiments, the projection of the heat radiation surface of thefirst heater 25 on the plane of thefirst end 40 has an outer contour shape matched with the shape of thefirst end 40, and the projection of thefourth heater 27 on the plane of thesecond end 41 has an outer contour shape matched with the shape of thesecond end 41, so that the temperature control effect is better. The projection of the heat radiation surface of thefirst heater 25 on the plane of thefirst end 40 at least partially covers thefirst end 40 of thereaction chamber 20; the projection of the heat radiating surface of thefourth heater 27 on the plane of thesecond end 41 at least partially covers thesecond end 41 of thereaction chamber 20. Therefore, the heat generated by thefirst heater 25 and thefourth heater 27 can be at least partially radiated to thefirst end 40 and thesecond end 41 of thereaction chamber 20 for temperature control.

In some embodiments, the outer diameter of thefirst heater 25 is between 100% and 110% of the outer diameter of thereaction chamber 20. The outer diameter of thefourth heater 27 is between 100% and 110% of the outer diameter of thereaction chamber 20.

Illustratively, the outer diameter of thefirst heater 25 is 100% of the outer diameter of thereaction chamber 20, which is equal to the outer diameter of thefirst end 40 of thereaction chamber 20. The outer diameter of thefourth heater 27 is 100% of the outer diameter of thereaction chamber 20, which is equal to the outer diameter of thesecond end 41 of thereaction chamber 20.

Illustratively, thereaction chamber 20 includes acylindrical cavity 60 and a circulartop cover 50. Thefirst heater 25 and thefourth heater 27 are both disc-shaped, are matched with the shape of thetop cover 50 and the bottom shape of thecavity 60, and are respectively arranged above thetop cover 50 and below thecavity 60. The surface of one side of thefirst heater 25 facing thecavity 60 and the side of thefourth heater 27 facing thecavity 60 are heat radiation surfaces, and the projection of the heat radiation surface of thefirst heater 25 on the plane of thefirst end 40 is circular and is consistent with the shape of thetop cover 50, and the shape of thetop cover 50 is the shape of thefirst end 40. The outer contour shape of the projection of thefourth heater 27 on the plane where thesecond end 41 is located is circular, and is consistent with the shape of the bottom surface of thecavity 60, and the shape of the bottom surface of thecavity 60 is the shape of thesecond end 41.

Thesecond heater 24 and thethird heater 26 are cylindrical, surround thechamber 60 from the side of thechamber 60, and are disposed coaxially with thechamber 60, so that thesecond heater 24 and thethird heater 26 are located at the same distance from thechamber 60. The surfaces of thesecond heater 24 and thethird heater 26 facing thecavity 60 are heat radiating surfaces, so that each of the side surfaces of thecavity 60 has a heat radiating surface vertically opposite to the heat radiating surface, thereby obtaining a better temperature control effect.

And, the projection of the heat radiation surface of thefirst heater 25 on the plane where thefirst end 40 is located completely covers thefirst end 40 of thereaction chamber 20; the projection of the heat radiation surface of thefourth heater 27 on the plane of thesecond end 41 completely covers thesecond end 41 of thereaction chamber 20. Therefore, each of the top and bottom of thereaction chamber 20 has a heat radiation surface directly opposite thereto, so that a better temperature control effect can be obtained.

Therefore, the shapes of thefirst heater 25, thesecond heater 24, thethird heater 26 and thefourth heater 27 are adapted to the overall shape of thereaction chamber 20, and thereaction chamber 20 can obtain a better temperature control effect.

In some embodiments, the distance between thefirst heater 25 and thefirst end 40 and the distance between the heat radiation surface of thefourth heater 27 and thesecond end 41 may be set according to the temperature requirements of thefirst end 40 and thesecond end 41.

Since thesecond end 41 of thereaction chamber 20 is used for placing thereaction material 30 and thefirst end 40 of thereaction chamber 20 is used for forming the target, there may be a difference in the reaction temperature required for thefirst end 40 and thesecond end 41 of thereaction chamber 20, and there may be a difference in the requirements for the distance between the heat radiation surface of thefirst heater 25 and thefirst end 40, and the distance between the heat radiation surface of thefourth heater 27 and thesecond end 41.

Illustratively, the reaction temperature required for thereaction mass 30 is high and the reaction temperature required for the reaction gas atmosphere is low, and therefore, the distance from the heat radiation surface of thefirst heater 25 to thefirst end 40 is set to be greater than or equal to the distance from the heat radiation surface of thefourth heater 27 to thesecond end 41.

In some embodiments, the heat radiating surface of thefirst heater 25 is spaced from thefirst end 40 by 20% to 80% of the axial length of thereaction chamber 20 in thereaction chamber 20. The heat radiating surface of thefourth heater 27 is spaced from thesecond end 41 by 10% to 50% of the axial length of thereaction chamber 20.

Illustratively, thefirst heater 25 is located directly above thefirst end 40 of thereaction chamber 20 at a distance of 40% of the axial length of thereaction chamber 20 from thefirst end 40 of thereaction chamber 20. Thefourth heater 27 is located directly below thesecond end 41 of thereaction chamber 20 at a distance of 20% of the axial length of thereaction chamber 20 from thesecond end 41 of thereaction chamber 20.

In fact, the distance between the heat radiation surface of thefirst heater 25 and thefirst end 40 and the distance between the heat radiation surface of thefourth heater 27 and thesecond end 41 can also be set as required, and it is preferable to meet the requirement of the heating temperature of thefirst end 40 and thesecond end 41, and prevent heat dissipation caused by an excessively large distance, thereby ensuring the heating efficiency of thefirst heater 25 and thefourth heater 27.

In some embodiments, thefirst heater 25 is further provided with a first throughhole 28, and the first throughhole 28 penetrates thefirst heater 25 and exposes thefirst end 40 of thereaction chamber 20, so that the user can detect the temperature of thefirst end 40 of thereaction chamber 20. A user may use an infrared temperature detector to emit infrared rays for detection toward the first throughhole 28 to detect the temperature of thefirst end 40 of thereaction chamber 20.

In some embodiments, thefourth heater 27 is provided with a second throughhole 29, the second throughhole 29 penetrates thefourth heater 27 and exposes thesecond end 41 of thereaction chamber 20 so that the user can detect the temperature of thesecond end 41 of thereaction chamber 20, and a rotation shaft is provided to drive thereaction chamber 20 to rotate around the axial direction of the rotation shaft. The user may emit infrared rays for detection toward the second throughhole 29 using an infrared temperature detector to detect the temperature of thesecond end 41 of thereaction chamber 20. The user can also drive thereaction chamber 20 to rotate by using a hollow rotating shaft which passes through the second throughhole 29, is fitted to the surface of thereaction chamber 20, has an aperture in the middle thereof, and exposes the surface of thesecond end 41 of thereaction chamber 20 through the aperture. Thus, the user is still able to detect the temperature of thesecond end 41 of thereaction chamber 20 using the infrared temperature detector. Specifically, the user uses an infrared temperature detector to emit infrared light toward the aperture, thereby detecting the temperature of thesecond end 41 of thereaction chamber 20.

Those skilled in the art can determine whether the corresponding through holes are required to be formed in thefirst heater 25 and thesecond heater 24 as needed. When the second throughhole 29 is not provided on thefourth heater 27, the rotation of thereaction chamber 20 may be achieved by means of a turntable or the like.

By properly setting the radial dimensions of the first throughhole 28 and the second throughhole 29, the influence of the first throughhole 28 on the heating effect of thefirst heater 25 and the influence of the second throughhole 29 on the heating effect of thesecond heater 24 can be reduced.

In some embodiments, the first through-hole 28 has an aperture that is between 20% and 100% of the radial dimension of thefirst end 40 of thereaction chamber 20. The second throughhole 29 has a diameter of between 30% and 60% of the radial dimension of thesecond end 41 of thereaction chamber 20.

Illustratively, the first through-hole 28 has a bore diameter that is 50% of the radial dimension of thefirst end 40 of thereaction chamber 20. The center of thefourth heater 27 is provided with a second throughhole 29, and the aperture of the second throughhole 29 is 30% of the radial size of thesecond end 41 of thereaction chamber 20.

The aperture of the first and second throughholes 28 and 29 can be determined as desired by those skilled in the art.

In some embodiments, the top of thesecond heater 24 is spaced from thefirst end 40 of thereaction chamber 20 by 0% to 10% of the axial length of thereaction chamber 20. The bottom of thethird heater 26 is spaced from thesecond end 41 of thereaction chamber 20 by 0% to 10% of the axial length of thereaction chamber 20.

Illustratively, the upper surface of thesecond heater 24 is flush with the top surface of thereaction chamber 20. The lower surface of thethird heater 26 is flush with the bottom surface of thereaction chamber 20.

Thesecond heater 24 and thethird heater 26 are used to provide thereaction chamber 20 with temperature control in the axial direction of thereaction chamber 20, so that the length of the heat radiation surface of thesecond heater 24 and thethird heater 26 in the axial direction of thereaction chamber 20 can be set in accordance with the expected stack height of the reaction material in thereaction chamber 20 and the dimension of the reaction gas atmosphere in the axial direction of thereaction chamber 20.

In some embodiments, the length of the heat radiation surface of thesecond heater 24 in the axial direction of thereaction chamber 20 is similar to the size of the reaction gas atmosphere in thereaction chamber 20 in the axial direction of thereaction chamber 20; the length of the heat radiation surface of thethird heater 26 in the axial direction of thereaction chamber 20 is similar to the stacking height of thereaction material 30 in thereaction chamber 20, so that thesecond heater 24 and thethird heater 26 can control the temperatures of thereaction material 30 and the reaction gas atmosphere, respectively. When the length of the reaction gas atmosphere in the axial direction of thereaction chamber 20 is small and the stacking height of thereaction material 30 is large, the heat radiation surface of thesecond heater 24 is shorter in the axial direction of thereaction chamber 20 than the heat radiation surface of thethird heater 26 in the axial direction of thereaction chamber 20.

In some embodiments, the ratio of the length of the reaction gas atmosphere in the axial direction of thereaction chamber 20 to the stacking height of thereaction material 30 is (1-5): 5-8, so that the ratio of the length of the heat radiation surface of thesecond heater 24 in the axial direction of thereaction chamber 20 to the length of the heat radiation surface of thethird heater 26 in the axial direction of thereaction chamber 20 is (1-5): 5-8.

In some other embodiments, the lengths of the heat radiation surfaces of thesecond heater 24 and thethird heater 26 in the axial direction of thereaction chamber 20 may be set as desired, for example, the lengths of the heat radiation surfaces of thesecond heater 24 and thethird heater 26 in the axial direction of thereaction chamber 20 are set to be equal.

In some embodiments, the length of thesecond heater 24 in the axial direction of thereaction chamber 20 is equal to the length of the heat radiation surface of thesecond heater 24 in the axial direction of thereaction chamber 20, and the length of thethird heater 26 in the axial direction of thereaction chamber 20 is equal to the length of the heat radiation surface of thethird heater 26 in the axial direction of thereaction chamber 20.

In some embodiments, a gap exists between thesecond heater 24 and thethird heater 26 to reduce electromagnetic interference between thesecond heater 24 and thethird heater 26.

Illustratively, the gap between thesecond heater 24 and thethird heater 26 ranges in size from 15mm to 30 mm.

In some embodiments, in order to ensure the heating efficiency of thesecond heater 24 and thethird heater 26, the distance between thesecond heater 24 and the side of thefirst end 40 and the distance between thethird heater 26 and the side of thesecond end 41 are controlled to be suitable, so as to prevent thesecond heater 24 and thethird heater 26 from being too far away from thereaction chamber 20, and the heat radiated by the two heaters is consumed by the air too much.

In some embodiments, thesecond heater 24 is between 15mm and 30mm from the side of thefirst end 40. Thethird heater 26 is located at a distance of between 15mm and 30mm from the side of thesecond end 41.

Illustratively, thesecond heater 24 is spaced 20mm from the side of thefirst end 40 and thethird heater 26 is spaced 20mm from the side of thesecond end 41.

In some embodiments, controlling the heating power of thesecond heater 24 and thethird heater 26 provides a gradient temperature field in the axial direction of thereaction chamber 20 for thereaction chamber 20, which helps to control the reaction rate of the reactant materials and the reaction gas environment.

Thesecond end 41 of thereaction chamber 20 is a stacking area of thereaction material 30, thefirst end 40 is used for forming thetarget 22, the section of thefirst end 40 corresponds to the upper half section of thereaction chamber 20, and the upper half section of thereaction chamber 20 is a distribution area of the reaction gas environment. Since the temperature required for thereaction mass 30 is high and the temperature required for the reaction gas atmosphere is low, the heating power of thesecond heater 24 can be controlled to be smaller than that of thethird heater 26 to provide a gradient temperature field gradually decreasing from thesecond end 41 to thefirst end 40 in the axial direction of thereaction chamber 20, and the decreasing direction of the gradient temperature field is opposite to the second growth direction of thetarget 22.

Illustratively, thetarget 22 is a SiC crystal, and by controlling the heating power of thesecond heater 24 and thethird heater 26, a gradient temperature field which is increased by 5 ℃ to 20 ℃ per centimeter and is directed from thefirst end 40 to thesecond end 41 along the axial direction of thereaction chamber 20 is provided for the process of preparing the SiC crystal, so that the transportation of gas-phase components in thereaction chamber 20 is accelerated, the transportation speed of the sublimated reaction gas to the surface of theseed crystal 22 for the growth of thetarget 22 is accelerated, the growth rate of thetarget 22 is increased, and the growth efficiency of thetarget 22 is improved.

In some embodiments, thesecond heater 24 is further configured to cooperate with the heating power of thefirst heater 25 to provide a desired temperature field for thetarget 22 at thefirst end 40, the temperature field having an isotherm parallel to or slightly convex from a line of the first growth direction of thetarget 22 at least at the growth interface of thetarget 22.

Illustratively, the first growth direction temperature gradient of the growth interface of thetarget 22 is less than 1K/cm.

In some embodiments, the semiconductor processing apparatus further comprises a power control module connected to the heating modules for individually controlling heating power of each heater in the heating modules.

In some embodiments, the power control module is used to control the heating power of thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27, respectively.

In some embodiments, the power control module includes a plurality of power control units respectively connected to thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27, and independently controlling heating powers of thefirst heater 25 to thefourth heater 27. By independently controlling the heating power of each heater, the temperature gradient in the first growth direction of the growth interface of thetarget 22 can be reduced, thereby suppressing the thermal stress inside the crystal when thetarget 22 is grown, reducing the crystal defects of thetarget 22, and growing a high-quality target 22 having a flat or slightly convex interface. Thereaction chamber 20 may also be provided with a gradient temperature field distributed along the second growth direction to increase the growth rate of thetarget 22.

In some embodiments, the ratio of the power applied by thefirst heater 25 to the total power is between 0% and 30%, the ratio of the power applied by thefourth heater 27 to the total power is between 50% and 80%, the ratio of the power applied by thesecond heater 24 to the total power is between 0% and 40%, and the ratio of the power applied by thethird heater 26 to the total power is between 0% and 50%. When the power ratio of the heater is 0, it is equivalent to not configuring the corresponding heater.

Illustratively, the silicon carbide powder is used to prepare theformation target 22, and thetarget 22 is a SiC crystal. The proportion of the heating power of thefirst heater 25 to the total power is 5%, the proportion of the heating power of thefourth heater 27 to the total power is 70%, the proportion of the heating power of thesecond heater 24 to the total power is 5%, and the proportion of the heating power of thethird heater 26 to the total power is 20%.

The silicon carbide powder is heated by thethird heater 26 and thefourth heater 27 to be sublimated, and the sublimated reaction gas is crystallized and grown on the surface of the siliconcarbide seed crystal 22 on theseed crystal holder 21.

By controlling the heating power of thefirst heater 25 and thesecond heater 24, an isotherm parallel to the first growth direction of the SiC crystal or slightly convex to the straight line of the first growth direction of the SiC crystal is formed on the growth interface of the SiC crystal, so that the SiC crystal has a flat or slightly convex growth interface, thereby obtaining a high-quality silicon carbide crystal. The temperature field can be seen in fig. 3.

In fact, the semiconductor processing apparatus is not limited to performing growth of SiC crystal. Because the heating power of each heater can be independently controlled, the method can be used for reducing the temperature gradient of thereaction chamber 20 in the axial direction and the radial direction, realizing the annealing or in-situ annealing of thetarget 22, maximizing the temperature of the position of theseed crystal 22, realizing the inversion of the temperature field in the crucible and preprocessing theseed crystal 22 before thetarget 22 grows.

And because the heating power of thefirst heater 25, thesecond heater 24, thethird heater 26 and thefourth heater 27 can be controlled independently, the preparation of thetarget object 22 with a large diameter is also facilitated, and thetarget object 22 with a larger radial size (for example, the radial size is 200mm) can be prepared on the basis of the existingtarget object 22 with the radial size of 150mm, so that the requirement of the growth of thetarget object 22 with a large diameter is met.

In some embodiments, thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 each include at least one of a resistance heater, an induction heater, an arc heater, an electron beam heater, an infrared heater, and a medium heater. In fact, the specific type of heater may be provided as desired.

Illustratively, thefirst heater 25, thesecond heater 24, thethird heater 26, and thefourth heater 27 are all resistance heaters.

Illustratively, the resistive heater is a graphite heater.

Illustratively, the resistive heater is a resistance wire heater.

The present application provides, in a second aspect, a method of heating atarget 22 for growth.

Fig. 4 is a flowchart illustrating a heating method for growing thetarget object 22 according to an embodiment.

In this embodiment, the heating method for the growth of thetarget object 22 uses the semiconductor processing apparatus of the above embodiment to achieve heating, thetarget object 22 is grown at thefirst end 40 of thereaction chamber 20, and the heating method includes the following steps: step S1: controlling a temperature distribution of thefirst end 40 of thereaction chamber 20 in the first growth direction of thetarget 22 by thefirst heater 25; step S2: controlling a temperature distribution profile of a side surface of thefirst end 40 of thereaction chamber 20 in a second growth direction of thetarget 22 by thesecond heater 24; step S3: controlling the temperature distribution of the side surface of thesecond end 41 of thereaction chamber 20 in the second growth direction by thethird heater 26; step S4: the temperature distribution of thesecond end 41 of thereaction chamber 20 in the first growth direction is controlled by thefourth heater 27.

And the heating power ratio of thefirst heater 25, thesecond heater 24, thethird heater 26 and thefourth heater 27 is (0-3): (0-4): (0-5): (5-8).

Since thefirst heater 25 is disposed above thefirst end 40 where thetarget 22 is located, the temperature field in the first growth direction of thetarget 22 can be controlled by thefirst heater 25, the isotherm of the growth interface of thetarget 22 can be adjusted as needed, a flat or slightly convex growth interface of thetarget 22 is obtained, and the quality of the obtainedtarget 22 is improved.

Moreover, since thesecond heater 24 and thethird heater 26 are disposed around thefirst end 40, thesecond heater 24 and thethird heater 26 at least have heat radiation surfaces distributed along the second growth direction of thetarget 22, and the heating powers of thesecond heater 24 and thethird heater 26 can be independently controlled, the temperature gradient of thereaction chamber 20 in the second growth direction can be controlled by thesecond heater 24 and thethird heater 26, so as to accelerate the reaction gas transportation speed and improve the growth speed of thetarget 22.

Moreover, since thefourth heater 27 is disposed below thesecond end 41, the temperature of thesecond end 41 can be controlled by thefourth heater 27 to provide a sufficient temperature for the reaction material placed at thesecond end 41, thereby accelerating the growth rate of thetarget 22.

Moreover, due to the more controllable temperature field environment, as the radial dimensions of the induction coil and thereaction chamber 20 increase, the temperature distribution in the first growth direction of the growth interface of thetarget 22 can also be kept uniform, which is beneficial for preparing high-quality large-diameter targets 22, such as large-diameter targets 22 with radial dimensions of more than 150 mm.

The above embodiments are merely examples of the present application, and not intended to limit the scope of the present application, and all equivalent structures or equivalent flow transformations made by the present specification and drawings, such as mutual combination of technical features between various embodiments, or direct or indirect application to other related technical fields, are all included in the scope of the present application.

Claims (10)

1. A semiconductor processing apparatus for preparing a target, comprising:

a reaction chamber including a first end and a second end sequentially arranged in an axial direction of the reaction chamber, and the target being formed at the first end;

a heating module comprising:

a first heater disposed above the first end and having at least a heat radiation surface distributed along a first growth direction of the target;

the second heater is arranged on the side surface of the first end and at least provided with a heat radiation surface distributed along the second growth direction of the target object, and the top of the second heater is higher than the plane where the first end of the reaction chamber is located or is flush with the plane where the first end of the reaction chamber is located;

the third heater is arranged below the second end and at least provided with a heat radiation surface distributed along the second growth direction of the target object, and the bottom of the third heater is lower than the plane where the second end of the reaction chamber is located or is flush with the plane where the second end of the reaction chamber is located;

a fourth heater provided at the second end side surface and having at least a heat radiation surface distributed along the first growth direction of the target;

the heating powers of the first heater, the second heater, the third heater and the fourth heater are mutually independent.

2. The semiconductor processing apparatus according to claim 1, wherein a projection of the heat radiation surface of the first heater on a plane on which the first end is located has an outer contour shape matching a shape of the first end, and a projection of the heat radiation surface of the first heater on a plane on which the first end is located at least partially covers the first end of the reaction chamber;

the projection of the heat radiation surface of the fourth heater on the plane of the second end at least partially covers the second end of the reaction chamber.

3. The semiconductor processing apparatus of claim 1 or 2, wherein the reaction chamber comprises a cylindrical chamber body and a circular top cover, wherein the first heater and the fourth heater are each in the shape of a disk, the second heater and the third heater are each in the shape of a cylinder, and the second heater and the third heater surround the chamber body, and the first heater and the fourth heater are respectively disposed above the top cover and below the bottom of the chamber body.

4. The semiconductor processing apparatus according to claim 1, wherein a length of the heat radiation face of the second heater in the axial direction of the reaction chamber is smaller than a length of the heat radiation face of the third heater in the axial direction of the reaction chamber.

5. The semiconductor processing apparatus according to claim 1, wherein a distance from the first end to a heat radiation surface of the first heater is greater than or equal to a distance from the second end to a heat radiation surface of the fourth heater.

6. The semiconductor processing apparatus of claim 1, wherein a gap exists between the second heater and the third heater, and the gap has a size in a range of 15mm to 30 mm.

7. The semiconductor processing apparatus of claim 1, wherein the first heater is further provided with a first through hole penetrating the first heater and exposing a first end of the reaction chamber, and/or:

the fourth heater is provided with a second through hole which penetrates through the fourth heater and exposes the second end of the reaction chamber.

8. The semiconductor processing apparatus of claim 1, further comprising a power control module connected to the heating modules for individually controlling heating power of each heater in the heating modules.

9. A heating method for target growth using the semiconductor processing apparatus of any one of claims 1 to 8, the target growth being at a first end of the reaction chamber, the heating method comprising:

controlling a temperature distribution of the first end of the reaction chamber in a first growth direction of the target by the first heater;

controlling the temperature distribution of the side surface of the first end of the reaction chamber in the second growth direction of the target object through the second heater;

controlling the temperature distribution of the side surface of the second end of the reaction chamber in the second growth direction through the third heater;

and controlling the temperature distribution of the second end of the reaction chamber in the first growth direction through the fourth heater.

10. The heating method according to claim 9, wherein a heating power ratio of the first heater, the second heater, the third heater and the fourth heater is (0-3): (0-4): (0-5): (5-8).

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