Base assembly for epitaxial furnace and epitaxial furnace

Abstract

The utility model discloses a base assembly for an epitaxial furnace and the epitaxial furnace, the base assembly for the epitaxial furnace comprises a base, and the base is suitable for bearing a tray of the epitaxial furnace; the protective part is arranged on the outer periphery of the base in a sleeving mode, and a protective layer is arranged on the outer peripheral face of the protective part. According to the base assembly for the epitaxial furnace, the base is not easy to deform, and the rotation stability of the base assembly is improved, so that the uniformity of an epitaxial wafer is improved, and fatal defects are also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor material manufacturing, in particular to a base assembly for an epitaxial furnace and an epitaxial furnace. Background Art

[0002] As a typical representative of wide bandgap semiconductor materials, silicon carbide semiconductors have characteristics such as high critical breakdown field strength, high saturated electron drift velocity, and high thermal conductivity. They can meet the working requirements of high-temperature, high-frequency, high-power, high-voltage, and radiation-resistant power electronic devices, and are an ideal power device material. Compared with traditional silicon devices, silicon carbide power devices have higher working voltages and frequencies, a current density that can reach four times that of silicon devices, significantly reduced power losses, better energy-saving effects, and higher reliability.

[0003] Silicon carbide epitaxial layers are usually prepared by chemical vapor deposition. Among them, the growth thickness and doping concentration uniformity of silicon carbide epitaxial layers have an important impact on the performance of silicon carbide devices. High uniformity can reduce the performance discreteness of silicon carbide devices and also improve the reliability of silicon carbide devices. Fatal defects are another type of epitaxial defect that affects the performance of silicon carbide devices and can directly cause device failure.

[0004] In related technologies, the function of the tray base of an epitaxial furnace is to carry the tray, and the tray is used to carry wafers. The tray base can drive the tray to rotate, enabling uniform growth of epitaxial wafers. During use, the surface of the tray base is coated with a silicon carbide coating, which will deform under thermal shock, thereby changing the temperature field of the tray and resulting in poor uniformity of the epitaxial wafers. In addition, the above-mentioned deformation will also cause unstable rotation of the tray base, friction with the lower half part of the epitaxial furnace, and a high rate of fatal defects in the epitaxial wafers. Summary of the Utility Model

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, an object of the utility model is to propose a base assembly for an epitaxial furnace, the base of which is not easily deformed, improving the rotational stability of the base assembly, thereby improving the uniformity of epitaxial wafers and reducing fatal defects.

[0006] Another object of the utility model is to propose an epitaxial furnace using the above base assembly.

[0007] The base assembly for an epitaxial furnace according to the first aspect embodiment of the utility model includes: a base, the base being adapted to carry the tray of the epitaxial furnace; a protective member, the protective member being sleeved on the outer periphery of the base, and a protective layer being provided on the outer peripheral surface of the protective member.

[0008] According to the base assembly for an epitaxial furnace of the present utility model, the protective layer on the protective member can protect the base, preventing the edges of the base from being etched by hydrogen, avoiding particles from falling onto the wafer surface, reducing fatal defects, and thus improving the quality of epitaxial wafer growth. In addition, without a protective layer on the base, deformation or bending during use is avoided, the rotational stability of the base is improved, the concentration uniformity of the epitaxial wafer is thereby improved, the service life of the epitaxial wafer is extended, and the fatal defects of the epitaxial wafer are reduced. Moreover, the stability and reliability of production are also improved. Additionally, the modification of the base assembly is small, facilitating implementation and processing.

[0009] According to some embodiments of the present utility model, the base is a graphite member; and / or, the protective member is a graphite member, and the protective layer is a SiC layer or a TaC layer.

[0010] According to some embodiments of the present utility model, the base includes: a support portion, on one side in the thickness direction of the support portion, a groove is formed, and the tray is adapted to be fitted in the groove; an extension portion, the extension portion is connected to the other side of the support portion, the extension portion is located on the outer peripheral side of the support portion, and the protective member is disposed on the surface of the extension portion facing the side where the groove is located.

[0011] According to some embodiments of the present utility model, a plurality of positioning holes are formed in one of the extension portion and the protective member, the plurality of positioning holes are arranged at intervals along the circumferential direction of one of the extension portion and the protective member, and a plurality of positioning posts are provided on the other of the extension portion and the protective member, the plurality of positioning posts are arranged at intervals along the circumferential direction of the other of the extension portion and the protective member, and the plurality of positioning posts are respectively fitted in the plurality of positioning holes.

[0012] According to some embodiments of the present utility model, the height of the positioning post is d1, and the depth of the positioning hole is d2, wherein d1 and d2 satisfy: d1 < d2.

[0013] According to some embodiments of the present utility model, the depth of the positioning hole is d2, and the thickness of the extension portion is d3, and d2 and d3 satisfy: d2 ≤ d3.

[0014] According to some embodiments of the present utility model, the side of the protective member away from the center of the base has a flanging, the flanging extends in the thickness direction of the protective member, and the end face of the free end of the flanging is higher than the side face of the extension portion away from the protective member.

[0015] According to some embodiments of the present utility model, a space is provided between the inner peripheral surface of the protective member and the outer peripheral surface of the support portion.

[0016] According to some embodiments of the present utility model, at least three exhaust channels are formed on one side surface of the base, the at least three exhaust channels are arranged at intervals along the circumferential direction of the base, one end of the exhaust channel penetrates the outer circumferential surface of the base, and the other end of the exhaust channel extends obliquely in a direction away from the radial line of the base.

[0017] According to some embodiments of the present utility model, the exhaust channel has a first side and a second side, one end of the first side and one end of the second side are spaced apart along the circumferential direction of the base, and the other end of the first side and the other end of the second side extend towards each other and are connected after approaching.

[0018] According to some embodiments of the present utility model, the connection line between one end of the first side and the center of one side surface of the base is a first radial line, the included angle between the first radial line and the first side is α1, the connection line between one end of the second side and the center of one side surface of the base is a second radial line, and the included angle between the second radial line and the second side is α2, wherein, α1 and α2 satisfy: α1 < α2.

[0019] According to some embodiments of the present utility model, α2 further satisfies: α2 ≤ 45°.

[0020] According to some embodiments of the present utility model, an assembly hole is formed on one side surface of the base, and the central axis of the assembly hole coincides with the central axis of the base.

[0021] According to some embodiments of the present utility model, the thickness of the protective layer is w, wherein, w satisfies: 30μm ≤ w ≤ 200μm.

[0022] An epitaxial furnace according to an embodiment of the second aspect of the present utility model includes a base assembly for an epitaxial furnace according to the above first aspect embodiment of the present utility model.

[0023] The additional aspects and advantages of the present utility model will be partly given in the following description, partly will become obvious from the following description, or will be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0025] Figure 1 is a schematic diagram of a base assembly according to an embodiment of the present utility model;

[0026] Figure 2 is Figure 1 an enlarged view of part A in

[0027] Figure 3 is a top view of the base of the base assembly according to an embodiment of the present invention;

[0028] Figure 4 is Figure 3 a sectional view taken along line a-a in

[0029] Figure 5 is Figure 4 an enlarged view of part B in

[0030] Figure 6 is a top view of the protective member of the base assembly according to an embodiment of the present invention;

[0031] Figure 7 is a bottom view of the protective member of the base assembly according to an embodiment of the present invention;

[0032] Figure 8 is Figure 7 a sectional view taken along line b-b in

[0033] Figure 9 is Figure 8 an enlarged view of part C in

[0034] Figure 10 is a bottom view of the base of the base assembly according to an embodiment of the present invention.

[0035] Reference numerals:

[0036] 100, base assembly;

[0037] 1, base; 11, support portion; 111, groove;

[0038] 12, extension portion; 121, positioning hole;

[0039] 13, exhaust passage; 131, first side; 132, second side;

[0040] 133, first radial line; 134, second radial line; 14, assembly hole;

[0041] 2, protective member; 21, protective layer; 22, positioning post; 23, flanging. Detailed implementation manners

[0042] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. Next, reference is made to Figures 1-10 describe the base assembly 100 for an epitaxial furnace according to the first aspect embodiment of the present invention.

[0043] As Figure 1 and Figure 2As shown, a susceptor assembly 100 for an epitaxial furnace according to an embodiment of the first aspect of the utility model comprises a base 1 and a protective member 2 .

[0044] Specifically, the base 1 is suitable for carrying a tray of an epitaxial furnace. The protective member 2 is sleeved on the outer periphery of the base 1 , and a protective layer 21 is provided on the outer periphery of the protective member 2 .

[0045] For example, in Figure 1 and Figure 2 In the example, the protective member 2 passes through the upper end of the base 1 and matches the outer periphery of the lower end portion of the base 1. The tray (not shown) is used to carry the wafer (not shown), and the base assembly 100 drives the tray to rotate so that the epitaxial layer of the wafer grows uniformly to form an epitaxial wafer. In other words, the rotation of the base assembly 100 can drive the tray and the wafer placed on the surface of the tray to rotate.

[0046] Compared with the conventional technology, the base assembly 100 is divided into two parts (base 1 and protective member 2). The protective layer 21 on the protective member 2 can protect the base 1, prevent the edge of the base 1 from being etched by hydrogen, and prevent the SiC particles from being blown onto the wafer on the tray by a large flow of hydrogen when there are many SiC particles deposited on the edge of the base 1, thereby reducing fatal defects and improving the quality of epitaxial wafer growth. In addition, there is no protective layer 21 on the base 1, which prevents the base 1 from being deformed, expanded or bent during use, and improves the stability of the rotation of the base 1. On the one hand, the uniformity of the tray temperature field is ensured during the entire use process, the uniformity of the doping concentration of the epitaxial wafer is improved, the service life of the epitaxial wafer is extended, and the reliability of the epitaxial wafer is improved. On the other hand, the friction with other components (such as the lower half moon) during the rotation of the base 1 is prevented, reducing the fatal defects of the epitaxial wafer. Moreover, the stability and reliability of production are also improved. In addition, the base assembly 100 has a small modification, which is easy to execute and process, thereby improving the processing efficiency of the base assembly 100.

[0047] According to the base assembly 100 for an epitaxial furnace of the utility model, the protective layer 21 on the protective member 2 can protect the base 1, prevent the edge of the base 1 from being etched by hydrogen, and prevent particles from falling onto the surface of the wafer, thereby reducing fatal defects and improving the quality of epitaxial wafer growth. In addition, there is no protective layer 21 on the base 1, which prevents deformation or bending during use, improves the stability of the rotation of the base 1, thereby improving the concentration uniformity of the epitaxial wafer, extending the service life of the epitaxial wafer, and reducing the fatal defects of the epitaxial wafer. Moreover, the stability and reliability of production are also improved. In addition, the base assembly 100 has been modified slightly, which is convenient for execution and processing.

[0048] According to some embodiments of the present invention, the base 1 is a graphite member; and / or, the protective member 2 is a graphite member, and the protective layer 21 is a SiC layer or a TaC layer. For example, the settings of the base 1, the protective member 2, and the protective layer 21 include the following situations: First, the base 1 is a graphite member. Second, the protective member 2 is a graphite member, and the protective layer 21 is a SiC layer or a TaC layer. Third, the base 1 is a graphite member. At the same time, the protective member 2 is a graphite member, and the protective layer 21 is a SiC layer or a TaC layer.

[0049] Thus, the graphite member has the properties of fire resistance, high temperature resistance, and good thermal conductivity, so that the base 1 and the protective member 2 are not easily deformed at high temperatures, improving the use stability of the base 1 and the protective member 2 and facilitating the growth of epitaxial wafers. The SiC layer has stable chemical properties, high thermal conductivity, small thermal expansion coefficient, and good wear resistance. The TaC layer has strong oxidation resistance and good wear resistance, thus improving the wear resistance of the protective layer 21. The protective layer 21 is not easily etched by hydrogen, improving the protective effect of the protective layer 21 on the protective member 2 and the base 1, and further facilitating the growth of epitaxial wafers and extending the service life of the base assembly 100. It should be noted that the protective layer 21 has high temperature resistance and etching resistance, but is not limited thereto.

[0050] According to some embodiments of the present invention, referring to Figure 1 and Figure 2 , the base 1 includes a support portion 11 and an extension portion 12. A groove 111 is formed on one side in the thickness direction of the support portion 11, and the tray is adapted to be fitted in the groove 111. The extension portion 12 is connected to the other side of the support portion 11. The extension portion 12 is located on the outer peripheral side of the support portion 11, and the protective member 2 is provided on the surface of the extension portion 12 facing the side where the groove 111 is located.

[0051] For example, in the examples of Figure 1 and Figure 2 , the support portion 11 is generally cylindrical, the extension portion 12 is generally annular, and the base 1 is generally in a T-shaped structure. The groove 111 is formed on the upper side of the support portion 11. The lower side of the support portion 11 is connected to the extension portion 12. The extension portion 12 extends circumferentially along the support portion 11, and the protective member 2 is located on the upper surface of the extension portion 12. From one side of the support portion 11 to the other side, the side wall of the groove 111 extends obliquely towards the center of the support portion 11. The radius of the lower edge line of the side wall of the groove 111 is smaller than the radius of the upper edge line of the side wall of the groove 111. The height of the lower edge line of the side wall of the groove 111 is lower than the height of the upper edge line of the side wall of the groove 111. The radius of the outer peripheral edge line on the upper side of the support portion 11 is larger than the radius of the upper edge line of the side wall of the groove 111. The height of the outer peripheral edge line on the upper side of the support portion 11 is the same as the height of the upper edge line of the side wall of the groove 111. The height of the bottom wall of the groove 111 is greater than the height of the lower surface of the base 1.

[0052] With such a setting, the groove 111 facilitates the assembly of the tray and the base 1, reduces the assembly difficulty between the tray and the base 1, and improves the assembly efficiency of the tray and the base 1. In addition, the extension portion 12 increases the area of the lower end of the base 1, improves the stability of the rotation of the base 1, and thus improves the quality of the epitaxial wafer. Moreover, the extension portion 12 supports the protective member 2, improving the use stability of the protective member 2. It should be noted that the support portion 11 and the extension portion 12 are of an integral structure, and the lower end of the support portion 11 protrudes from the outer peripheral side of the support portion 11 to form the extension portion 12. There is a gap between the side wall of the groove 111 and the tray.

[0053] According to some embodiments of the present invention, a plurality of positioning holes 121 are formed in one of the extension portion 12 and the protective member 2, the plurality of positioning holes 121 are arranged at intervals along the circumferential direction of one of the extension portion 12 and the protective member 2, and a plurality of positioning posts 22 are provided on the other of the extension portion 12 and the protective member 2, the plurality of positioning posts 22 are arranged at intervals along the circumferential direction of the other of the extension portion 12 and the protective member 2, and the plurality of positioning posts 22 are respectively fitted into the plurality of positioning holes 121. In the description of the present invention, the meaning of "a plurality of" is two or more.

[0054] For example, the setting of the positioning holes 121 and the positioning posts 22 includes the following situations: First, a plurality of positioning holes 121 are formed in the extension portion 12, the plurality of positioning holes 121 are arranged at intervals along the circumferential direction of the extension portion 12, a plurality of positioning posts 22 are provided on the protective member 2, the plurality of positioning posts 22 are arranged at intervals along the circumferential direction of the protective member 2, and the plurality of positioning posts 22 are respectively fitted into the plurality of positioning holes 121 (as Figure 3 and Figure 7 shown). Second, a plurality of positioning holes 121 are formed in the protective member 2, the plurality of positioning holes 121 are arranged at intervals along the circumferential direction of the protective member 2, a plurality of positioning posts 22 are provided on the extension portion 12, the plurality of positioning posts 22 are arranged at intervals along the circumferential direction of the extension portion 12, and the plurality of positioning posts 22 are respectively fitted into the plurality of positioning holes 121.

[0055] Such as Figure 1 、 Figure 3 and Figure 7In the example, the cross-sectional shape of the positioning post 22 and the cross-sectional shape of the positioning hole 121 are approximately circular. The positioning post 22 is located on the lower surface of the protective member 2, and the positioning hole 121 is located on the upper surface of the extension portion 12. The two positioning holes 121 are equally spaced, and the two positioning holes 121 are symmetric about the center of the extension portion 12. The two positioning posts 22 are equally spaced, and the two positioning posts 22 are symmetric about the center of the extension portion 12. It should be noted that multiple positioning posts 22 are respectively and correspondingly fitted into multiple positioning holes 121, or multiple positioning posts 22 are fitted into one positioning hole 121. Among them, the number of the positioning holes 121 is an even number. The cross-sectional shape of the positioning post 22 and the cross-sectional shape of the positioning hole 121 are not limited to circular. When multiple positioning posts 22 are respectively and correspondingly fitted into multiple positioning holes 121, the number, position, and shape of the positioning posts 22 are consistent with the number, position, and shape of the positioning holes 121.

[0056] With such a setting, the positioning post 22 is fitted with the positioning hole 121 to limit the assembly of the protective member 2 and the base 1, strengthening the assembly stability of the protective member 2 and the base 1, ensuring that the protective member 2 can rotate synchronously with the base 1, avoiding friction between the protective member 2 and the base 1, and thus extending the service life of the protective member 2 and the base 1.

[0057] According to some embodiments of the present invention, referring to Figure 5 and Figure 9 , the height of the positioning post 22 is d1, and the depth of the positioning hole 121 is d2. Among them, d1 and d2 satisfy: d1 < d2. Thus, the positioning post 22 can be completely assembled into the positioning hole 121, making the lower surface of the protective member 2 fit with the upper surface of the extension portion 12, avoiding hydrogen from entering between the protective member 2 and the extension portion 12, improving the protection of the extension portion 12 by the protective member 2, and further avoiding the extension portion 12 from being etched by hydrogen.

[0058] Furthermore, referring to Figure 4 and Figure 5 , the depth of the positioning hole 121 is d2, and the thickness of the extension portion 12 is d3. d2 and d3 satisfy: d2 ≤ d3. For example, when the depth of the positioning hole 121 is less than the thickness of the extension portion 12, the positioning hole 121 does not penetrate the extension portion 12. When the depth of the positioning hole 121 is equal to the thickness of the extension portion 12, the positioning hole 121 penetrates the extension portion 12. Thus, the flexibility of setting the depth of the positioning hole 121 is improved, facilitating the setting of the depth of the positioning hole 121 according to the actual use situation. In addition, when the positioning hole 121 penetrates the extension portion 12, the difficulty of forming the positioning hole 121 is reduced, and the production efficiency of the positioning hole 121 is improved.

[0059] According to some embodiments of the present invention, referring to Figures 7-9, one side of the protective member 2 away from the center of the base 1 has a flanging 23, the flanging 23 extends along the thickness direction of the protective member 2, and the end face of the free end of the flanging 23 is higher than the side face of the extension portion 12 away from the protective member 2. For example, in Figures 7-9 In the example, the flanging 23 is located on the outer peripheral side of the protective member 2, the flanging 23 extends downward, and the lower end face of the flanging 23 is higher than the lower side face of the extension portion 12.

[0060] With such a setting, the flanging 23 wraps the outer peripheral side of the extension portion 12, increasing the protection area of the protective member 2 for the extension portion 12, thereby further protecting the extension portion 12 and further avoiding the extension portion 12 from being etched by hydrogen. In addition, it also avoids the free end of the flanging 23 from contacting and rubbing against other components (such as the lower half member) during the rotation of the base 1, so that the protective member 2 can rotate normally with the base 1, and further ensures that the base assembly 100 can be used normally for a long time. It should be noted that the outer and inner edges of the end face of the free end of the flanging 23 are at the same height.

[0061] Optionally, referring to Figure 2 , there is a gap between the inner peripheral surface of the protective member 2 and the outer peripheral surface of the support portion 11. For example, in Figure 2 , Figure 3 and Figure 6 In the example, the radius of the inner peripheral surface of the protective member 2 is greater than the radius of the outer surface of the support portion 11. With such a setting, during the assembly of the protective member 2 and the base 1, the protective member 2 can easily pass through the support portion 11 and be assembled with the extension portion 12, thereby reducing the assembly difficulty of the protective member 2 and the base 1 and improving the assembly efficiency of the base assembly 100. In addition, when the protective member 2 expands at high temperature, it avoids the protective member 2 from squeezing the support portion 11, thereby avoiding damage to the protective member 2.

[0062] According to some embodiments of the present invention, referring to Figure 10 , at least three exhaust channels 13 are formed on one side surface of the base 1, the at least three exhaust channels 13 are arranged at intervals along the circumferential direction of the base 1, one end of the exhaust channel 13 penetrates the outer peripheral surface of the base 1, and the other end of the exhaust channel 13 extends obliquely in a direction away from the radial line of the base 1.

[0063] For example, in Figure 10 In the example, the exhaust channel 13 is formed on the lower side surface of the base 1, one end of the exhaust channel 13 away from the center of the base 1 (i.e., one end of the above exhaust channel 13) penetrates the outer peripheral surface of the base 1, and one end of the exhaust channel 13 close to the center of the base 1 (i.e., the other end of the above exhaust channel 13) extends obliquely in a direction away from the radial line of the base 1. The radial line of the base 1 is the radius line from the above-mentioned one end of the exhaust channel 13 to the center of the base 1 (such as Figure 10(the dashed lines in the figure). The three exhaust channels 13 have the same inclination direction and are symmetric about the center of the base 1. After the air-floating gas (such as other inert gases except hydrogen and nitrogen) is blown out from the lower half part (not shown in the figure), the air-floating gas blows towards the other end of the exhaust channel 13, and the air-floating gas flows along the exhaust channel 13 and is discharged from the base 1. With such an arrangement, the exhaust channel 13 can be used to evacuate the air-floating gas, avoiding the accumulation of the air-floating gas under the base 1 and affecting the rotation of the base 1, thereby improving the smoothness of the rotation of the base 1 and further improving the quality of the epitaxial wafer growth. In addition, the inclination direction of the three exhaust channels 13 is the same as the rotation direction of the base 1, and the air-floating gas is suspended out, which also facilitates the air-floating gas to drive the rotation of the base 1 and improves the smoothness of the rotation of the base 1.

[0064] According to some embodiments of the present invention, referring to Figure 10 , the exhaust channel 13 has a first side 131 and a second side 132. One end of the first side 131 and one end of the second side 132 are spaced apart along the circumferential direction of the base 1, and the other end of the first side 131 and the other end of the second side 132 extend towards each other and are connected.

[0065] For example, in the Figure 10 example, one end of the first side 131 far from the center of the base 1 is spaced apart from one end of the second side 132 far from the center of the base 1, and one end of the first side 131 close to the center of the base 1 is connected to one end of the second side 132 close to the center of the base 1, that is, along the direction away from the radial line of the base 1, the width of the exhaust channel 13 gradually decreases.

[0066] With such an arrangement, when the air-floating gas is discharged, the discharge rate of the air-floating gas is increased, further avoiding the accumulation of the air-floating gas under the base 1, thereby further improving the stability of the rotation of the base 1. In addition, the first side 131 and the second side 132 have a simple structure and are easy to produce, thus improving the production efficiency of the exhaust channel 13.

[0067] According to some embodiments of the present invention, referring to Figure 10 , the connection line between one end of the first side 131 and the center of one side surface of the base 1 is the first radial line 133, the included angle between the first radial line 133 and the first side 131 is α1, the connection line between one end of the second side 132 and the center of one side surface of the base 1 is the second radial line 134, and the included angle between the second radial line 134 and the second side 132 is α2, where α1 and α2 satisfy: α1 < α2. With such an arrangement, it is effectively ensured that the exhaust channel 13 is oriented towards the direction close to the center of the base 1, and the width of the exhaust channel 13 gradually decreases, that is, along the direction away from the radial line of the base 1, the width of the exhaust channel 13 gradually decreases, thereby improving the exhaust rate of the exhaust channel 13.

[0068] According to some embodiments of the present utility model, α2 further satisfies: α2 ≤ 45°. For example, when α2 is greater than 45°, the inclination angle of the second side 132 relative to the second radial line 134 is relatively large, and the inclination angle of the exhaust passage 13 relative to the radial line is relatively large. When the aerostatic gas flows out along the exhaust passage 13, it is not easy to drive the base 1 to rotate, reducing the rotation speed of the base 1, thereby affecting the growth of the epitaxial wafer. Thus, by setting the included angle α2 between the second radial line 134 and the second side 132 to be α2 ≤ 45°, the inclination angle of the second side 132 relative to the second radial line 134 is reasonably set, and the inclination angle of the exhaust passage 13 relative to the radial line is reasonably set. When the aerostatic gas flows out along the exhaust passage 13, it is easy to drive the base 1 to rotate, increasing the rotation speed of the base 1, thereby avoiding affecting the growth of the epitaxial wafer and improving the quality of the epitaxial wafer.

[0069] According to some embodiments of the present utility model, with reference to Figure 1 and Figure 10 , an assembly hole 14 is formed on one side surface of the base 1, and the central axis of the assembly hole 14 coincides with the central axis of the base 1. For example, in the examples of Figure 1 and Figure 10 , the assembly hole 14 is formed on the lower side surface of the base 1. With such a setting, the arrangement of the assembly hole 14 facilitates the assembly of the base 1 with other components (such as a rotating shaft), thereby improving the assembly efficiency of the base 1. In addition, when the base 1 rotates, it rotates along the central axis of the base 1, improving the rotation stability of the base 1, thereby improving the growth quality of the epitaxial wafer. Among them, a rotating shaft (not shown in the figure) is provided at the assembly hole 14, and the other end of the rotating shaft is assembled with the lower half moon member. The assembly hole 14 and the rotating shaft have a simple structure and are easy to assemble.

[0070] According to some embodiments of the present utility model, the thickness of the protective layer 21 is w, where w satisfies: 30 μm ≤ w ≤ 200 μm. For example, when the thickness w of the protective layer 21 is less than 30 μm, the thickness of the protective layer 21 is small, and the protective layer 21 is easily etched through by hydrogen, failing to achieve the protection effect. When the thickness w of the protective layer 21 is greater than 200 μm, the thickness of the protective layer 21 increases, and after the protective layer 21 is deformed, it is easily detached from the protective member 2, thereby shortening the service life of the protective member 2 and reducing the protective effect of the protective member 2 on the base 1, thus increasing the critical defect. Therefore, by setting the thickness w of the protective layer 21 to satisfy 30 μm ≤ w ≤ 200 μm, the thickness of the protective layer 21 is reasonably set, avoiding the protective layer 21 being easily etched through by hydrogen, thereby improving the protection effect. In addition, it is avoided that the protective layer 21 is easily detached from the protective member 2 after deformation, prolonging the service life of the protective member 2 and improving the protective effect of the protective member 2 on the base 1, thereby reducing the critical defect. Among them, the base assembly 100 is applicable to the growth of silicon carbide epitaxial wafers of different sizes (for example, 4 inches, 6 inches, 8 inches, etc.), that is, the size of the base assembly 100 can be set according to the size of the silicon carbide epitaxial wafer, thereby significantly improving the quality of the silicon carbide epitaxial wafer.

[0071] Among them, the embodiments and comparative examples are set as follows:

[0072] Embodiment 1, the base assembly 100 includes a base 1 and a protective member 2, and the protective layer 21 is wrapped around the outer peripheral surface of the protective member 2.

[0073] Comparative Example 1, when the base 1 and the protective member 2 are of an integral structure, the base assembly 100 is a graphite member, and the entire outer periphery of the base assembly 100 is covered with a protective layer.

[0074] Comparative Example 2, when the base 1 and the protective member 2 are of an integral structure, the base assembly 100 is a graphite member, and there is no protective layer 21 on the upper side surface of the base assembly 100 (including the side wall of the groove 111 and the outer peripheral edge of the groove 111), and there is a protective layer 21 on the remaining part of the base assembly 100.

[0075] Comparative Example 3, when the base 1 and the protective member 2 are of an integral structure, the base assembly 100 is a graphite member, and there is no protective layer 21 on the base assembly 100.

[0076] A doping concentration tester 530L is used to test the doping concentration of the epitaxial wafer, and a surface defect detector Candela 8520 is used to test the types and quantities of defects. The doping concentration uniformity, critical defect density of the epitaxial wafers produced in each implementation process, and the service life of the base in the examples are statistically analyzed.

[0077] During the use of Example 1, no deformation occurred, and the doping concentration uniformity and fatal defects remained stable, and it could be used until the standard service life.

[0078] During the use of Comparative Example 1, the protective layer 21 on the upper side of the base assembly 100 did not contact a large flow of hydrogen. The protective layer 21 on the upper side of the base assembly 100 continuously decomposed at high temperature and evaporated onto the tray, affecting the fatal defects. Subsequently, there was no protective layer 21 on the upper side of the base assembly 100, and there was a protective layer 21 on the remaining parts of the base assembly 100, which was prone to deformation and bending, and the doping concentration uniformity and fatal defects fluctuated greatly.

[0079] During the use of Comparative Example 2, it was prone to deformation and bending, and the doping concentration uniformity and fatal defects fluctuated greatly.

[0080] During the use of Comparative Example 3, no deformation occurred during the use, the doping concentration uniformity was stable, but the fatal defects fluctuated greatly.

[0081] Therefore, during the use of the base assembly 100 of the present application, the quality of the epitaxial wafers generated is better.

[0082] The epitaxial furnace (not shown in the figure) according to the second aspect embodiment of the present invention includes the base assembly 100 for the epitaxial furnace according to the first aspect embodiment of the present invention above.

[0083] By adopting the above base assembly 100, the use effect of the epitaxial furnace according to the present invention is improved.

[0084] The other constitutions and operations of the epitaxial furnace according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0085] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "length", "width", "thickness", "upper", "lower", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0086] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0087] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. A susceptor assembly for an epitaxial furnace, characterized in that, Comprising: A base, the base being adapted to carry a tray of the epitaxial furnace, the base including a support portion and an extension portion, a groove being formed on one side in the thickness direction of the support portion, the tray being adapted to fit within the groove, the extension portion being connected to the other side of the support portion, the extension portion being located on the outer peripheral side of the support portion; A protective member, the protective member being provided on a surface of the extension portion facing the side where the groove is located, a protective layer being provided on an outer peripheral surface of the protective member.

2. The pedestal assembly for an epitaxial furnace according to claim 1, wherein, The base is a graphite member; and / or The protective member is a graphite member, and the protective layer is a SiC layer or a TaC layer.

3. The pedestal assembly for an epitaxial furnace according to claim 1, characterized in that, A plurality of positioning holes are formed in one of the extension portion and the protective member, and the plurality of positioning holes are arranged at intervals along the circumferential direction of the one of the extension portion and the protective member. A plurality of positioning posts are provided on the other of the extension portion and the protective member, and the plurality of positioning posts are arranged at intervals along the circumferential direction of the other of the extension portion and the protective member, and the plurality of positioning posts are respectively fitted into the plurality of positioning holes.

4. The pedestal assembly for an epitaxial furnace according to claim 3, characterized in that, The height of the positioning post is d1, and the depth of the positioning hole is d2, wherein d1 and d2 satisfy: d1 < d2.

5. The pedestal assembly for an epitaxial furnace according to claim 3, characterized in that, The depth of the positioning hole is d2, and the thickness of the extension portion is d3, and d2 and d3 satisfy: d2 ≤ d3.

6. The pedestal assembly for an epitaxial furnace according to claim 1, characterized in that, One side of the protective member away from the center of the base has a flanging, the flanging extends in the thickness direction of the protective member, and the end face of the free end of the flanging is higher than the side face of the extension portion away from the protective member.

7. The pedestal assembly for an epitaxial furnace according to claim 1, wherein, A space is provided between the inner peripheral surface of the protective member and the outer peripheral surface of the support portion.

8. The pedestal assembly for an epitaxial furnace according to claim 1, wherein, At least three exhaust channels are formed on one side surface of the base, the at least three exhaust channels are arranged at intervals along the circumferential direction of the base, one end of the exhaust channel penetrates the outer peripheral surface of the base, and the other end of the exhaust channel extends obliquely in a direction away from the radial line of the base.

9. The pedestal assembly for an epitaxial furnace according to claim 8, wherein, The exhaust channel has a first side edge and a second side edge, one end of the first side edge and one end of the second side edge are spaced apart along the circumferential direction of the base, and the other end of the first side edge and the other end of the second side edge extend towards each other and are connected after that.

10. The pedestal assembly for an epitaxial furnace according to claim 9, wherein, A connection line between the one end of the first side edge and the center of the one side surface of the base is a first radial line, an angle between the first radial line and the first side edge is α1, a connection line between the one end of the second side edge and the center of the one side surface of the base is a second radial line, an angle between the second radial line and the second side edge is α2, wherein α1 and α2 satisfy: α1 < α2.

11. The pedestal assembly for an epitaxial furnace according to claim 10, wherein, α2 further satisfies: α2 ≤ 45°.

12. The pedestal assembly for an epitaxial furnace according to claim 1, characterized in that, An assembly hole is formed on one side surface of the base, and a central axis of the assembly hole coincides with a central axis of the base.

13. The susceptor assembly for an epitaxial furnace according to any one of claims 1-12, characterized in that, The thickness of the protective layer is w, wherein w satisfies: 30μm ≤ w ≤ 200μm.

14. An epitaxial furnace, characterized in that, Comprising a base component for an epitaxial furnace according to any one of claims 1-13.

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