Epitaxial base and epitaxial equipment

Abstract

The utility model provides an epitaxy base and epitaxy equipment. The epitaxy base comprises a base main body; the base main body comprises a bearing table and a sunken part, the bearing table is arranged at the edge of the base main body, the bearing table is connected with the sunken part to form a bearing surface for bearing a wafer, the sunken part is inwards sunken relative to the bearing table in the direction away from the wafer, and the wafer is erected on the bearing table and is in contact with the sunken part in the epitaxial process; the concave part is provided with at least two grooves, the grooves are formed in the circumferential direction of the base body, and the at least two grooves are distributed in the radial direction of the base body. According to the configuration, one side, close to the wafer, of the base main body has a concave-convex appearance, so that the temperature distribution of the groove area is changed, the heating and heat transfer of the back surface of the wafer are changed, the temperature of the surface of the wafer is changed, the change of the deposition rate is caused, and the change of the deposition rate caused by other hardware or airflow is compensated; appropriate compensation can improve the flatness and thickness uniformity of wafer epitaxy.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, in particular to an epitaxial base and epitaxial equipment. Background Art

[0002] The epitaxial growth process utilizes the principle of nucleation due to similarity of two-dimensional structures on the crystal interface to grow another single crystal layer with a complete lattice and different impurity concentrations and thicknesses on a single crystal wafer along its original crystal axis.

[0003] Taking the homogeneous single crystal epitaxy of wafers as an example, thickness uniformity and resistivity uniformity have always been the main directions for improving their quality. The usual method is to achieve this by optimizing the gas flow field characteristics of carrier gas, doping gas, trichlorosilane (TCS), etc., or by optimizing the temperature distribution.

[0004] The epitaxial base is a graphite substrate with a layer of SiC (silicon carbide) coating grown on the surface using the Chemical Vapor Deposition (CVD) process. During the epitaxial process, the graphite base serves as a carrier for the wafer at high temperature and plays an important role in the temperature distribution and airflow distribution of the wafer.

[0005] However, the existing epitaxial equipment cavity structure dimensions, gas path structure, heating lamps and heat-reflecting metal plates are all limited by the original design and safety characteristics of the equipment. There is only a certain amount of room for adjustment and they cannot meet the uniformity requirements of current high-end products. Utility Model Content

[0006] The utility model aims to provide an epitaxial base and an epitaxial device to solve the problem that the adjustment space of the existing epitaxial device is limited and cannot meet the uniformity requirements of current high-end products.

[0007] In order to achieve the above-mentioned object, the utility model provides an epitaxial base, comprising: a base body;

[0008] The base body includes a carrier platform and a recessed portion, wherein the carrier platform is arranged at the edge of the base body, the carrier platform is connected to the recessed portion to form a carrier surface for carrying a wafer, the recessed portion is concave relative to the carrier platform in a direction away from the wafer, the wafer is placed on the carrier platform, and the wafer can contact the recessed portion during the epitaxial process;

[0009] The recessed portion is provided with at least two grooves, the grooves are arranged along the circumference of the base body, and at least two of the grooves are arranged along the radial direction of the base body.

[0010] Optionally, the side wall of the groove is an inclined surface or a curved surface.

[0011] Optionally, the grooves are symmetrically arranged along the radial direction of the base body.

[0012] Optionally, the cross-sectional shape of the base body in a direction parallel to the bearing surface is circular, and the recessed portion includes a first groove and a second groove, the lowest point of the first groove in the axial direction of the base body coincides with the center of the circle, and the second groove is located on the outside of the first groove in the radial direction of the base body.

[0013] Optionally, the distance between the first groove and the center of the circle along the radial direction of the base body is between 20 mm and 40 mm; the depth of the first groove in the axial direction of the base body is between 0.1 mm and 1.5 mm;

[0014] The minimum distance of the second groove from the center of the circle along the radial direction of the base body is between 50mm and 80mm; the maximum distance of the second groove from the center of the circle along the radial direction of the base body is between 110mm and 140mm; the depth of the second groove in the axial direction of the base body is between 0.1mm and 1.5mm.

[0015] Optionally, the cross-sectional shape of the base body in a direction parallel to the bearing surface is circular, the recessed portion includes a third groove and a fourth groove, the lowest point of the third groove in the axial direction of the base body does not coincide with the center of the circle, and the fourth groove is located on the outside of the third groove in the radial direction of the base body.

[0016] Optionally, the minimum distance of the third groove from the center of the circle along the radial direction of the base body is between 10 mm and 40 mm; the maximum distance of the third groove from the center of the circle along the radial direction of the base body is between 40 mm and 110 mm; the depth of the third groove in the axial direction of the base body is between 0.1 mm and 1.5 mm;

[0017] The minimum distance of the fourth groove from the center of the circle along the radial direction of the base body is between 70mm and 120mm; the maximum distance of the fourth groove from the center of the circle along the radial direction of the base body is between 120mm and 150mm; the depth of the third groove in the axial direction of the base body is between 0.1mm and 1.5mm.

[0018] Optionally, a connecting platform is provided between two adjacent grooves in the radial direction of the base body, and the connecting platform is arranged along the circumference of the base body.

[0019] Optionally, the angle between the plane where the connecting platform is located and the plane where the supporting platform is located is α, then 0°≤α<90° and 90°<α≤180°.

[0020] In order to achieve the above object, the utility model also provides an epitaxial device, including the epitaxial base as described above.

[0021] Compared with the existing epitaxial equipment, the epitaxial base and epitaxial equipment provided by the utility model have the following advantages:

[0022] The present application forms a concave-convex appearance on the side of the base body close to the wafer by arranging at least two grooves on the recessed portion, wherein the grooves are arranged along the circumference of the base body, and at least two grooves are arranged along the radial direction of the base body. The thermal conductivity and gas properties at the grooves are different from those in other areas, resulting in a change in the temperature distribution in the groove area, causing changes in the heating and heat transfer on the back of the wafer, thereby changing the temperature of the wafer surface and causing a change in the deposition rate, so as to compensate for the change in the deposition rate caused by other hardware or airflow. Appropriate compensation can improve the flatness and thickness uniformity of the wafer epitaxy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A top view of a first epitaxial base provided in an embodiment of the utility model;

[0024] Figure 2 A schematic diagram of loading a first epitaxial base and a wafer provided in an embodiment of the utility model;

[0025] Figure 3 A top view of a second epitaxial base provided in an embodiment of the utility model;

[0026] Figure 4 A schematic diagram of loading a second epitaxial base and a wafer provided in an embodiment of the utility model;

[0027] Figure 5 A top view of a third epitaxial base provided in an embodiment of the utility model;

[0028] Figure 6 A schematic diagram of loading a third epitaxial base and a wafer provided in an embodiment of the utility model;

[0029] Figure 7 A top view of a fourth epitaxial base provided in an embodiment of the utility model;

[0030] Figure 8 A schematic diagram of loading a fourth epitaxial base and a wafer provided in an embodiment of the utility model;

[0031] Fig. 9 A schematic diagram of loading a fifth epitaxial base and a wafer provided in an embodiment of the utility model;

[0032] The description of each reference numeral is as follows:

[0033] 10-base body; 100-carrying platform; 101-recessed portion; 102-connecting platform; 1011-first groove; 1012-second groove; 1013-third groove; 1014-fourth groove;

[0034] 20- boss; 30- wafer; 40- heating unit;

[0035] X-circumferential; Y-radial; Z-axial. DETAILED DESCRIPTION

[0036] In order to make the purpose, advantages and features of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0037] As used in this specification, the singular forms "a", "an" and "the" include plural objects, the term "or" is generally used to include the meaning of "and / or", the term "several" is generally used to include the meaning of "at least one", and the term "at least two" is generally used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" and "the proximal end" and "the distal end" generally refer to two corresponding parts, which include not only the endpoints, and the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. In addition, as used in this specification, an element disposed on another element generally only indicates that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements may be direct or indirect through an intermediate element, and it cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element may be in any orientation such as inside, outside, above, below or on one side of another element, unless the content clearly indicates otherwise. The terms "upper", "lower", "top" and "bottom" are generally relative position relationships arranged in the direction of gravity; the terms "vertical, vertical direction" generally refer to the direction of gravity, which is generally perpendicular to the ground, and "horizontal, horizontal plane direction" generally refers to the direction parallel to the ground; for ordinary technicians in this field, the specific meanings of the above terms in this specification can be understood according to specific circumstances.

[0038] The utility model aims to provide an epitaxial base and an epitaxial device to solve the problem that the adjustment space of the existing epitaxial device is limited and cannot meet the uniformity requirements of current high-end products.

[0039] Those skilled in the art can understand that the epitaxial growth process is a process of growing a single crystal layer with different impurity concentrations and thicknesses on a single wafer by using the principle of nucleation of two-dimensional structural similarity on a crystal cross section. Epitaxy includes homogeneous epitaxy and heterogeneous epitaxy, and an insulating material with excellent isolation performance needs to be used as an epitaxial substrate. The epitaxial layer can have a different conductivity type from the original single wafer. By utilizing this characteristic, a PN junction can be directly prepared by epitaxial growth. Through the combination of different types, semiconductor devices and integrated circuits have various functions. Epitaxial growth methods are divided into vapor phase epitaxy, liquid phase epitaxy, and molecular beam epitaxy. This embodiment takes the homogeneous single crystal epitaxy of a wafer as an example, and uses vapor phase epitaxy to perform an epitaxial growth process. In the epitaxial process, the epitaxial base, as a carrier in the wafer heating process, plays an important role in the temperature distribution and airflow distribution of the wafer, but the components and auxiliary equipment in the prior art are subject to the size and safety requirements of the original equipment, and cannot be adjusted significantly, which easily causes the wafer to fail to meet the uniformity requirements of high-end products. Based on this, an embodiment of the utility model provides an epitaxial base and an epitaxial device, which changes the appearance of the epitaxial base by setting a plurality of grooves on the side of the epitaxial base close to the wafer, making its surface concave-convex, thereby changing the temperature of the wafer surface, causing a change in the deposition rate, so as to compensate for the change in the deposition rate caused by other hardware or airflow, and ultimately improve the flatness and thickness uniformity of the wafer epitaxy.

[0040] The following description is given with reference to the accompanying drawings.

[0041] Please refer to Figure 1 to Figure 2 The utility model provides an epitaxial base, including: a base body 10; the base body 10 includes a carrier 100 and a recessed portion 101, the carrier 100 is arranged at the edge of the base body 10, the carrier 100 is connected to the recessed portion 101, forming a carrying surface for carrying a wafer 30, the recessed portion 101 is concave relative to the carrier 100 in a direction away from the wafer 30, the wafer 30 is mounted on the carrier 100, and the wafer 30 can contact the recessed portion 101 during the epitaxial process; the recessed portion 101 is provided with at least two grooves, the grooves are arranged along the circumferential direction X of the base body 10, and at least two grooves are arranged along the radial direction Y of the base body 10. It should be noted that when the wafer 30 is not deformed, its state is as follows: Figure 1 As shown, the back side of the wafer 30 (in this embodiment, the back side of the wafer 30 is the side of the wafer 30 close to the recessed portion 101) is a plane and overlaps the support platform 100 to support the wafer 30; during the epitaxial production process, the wafer 30 is deformed by heat, and the back side of the wafer 30 is an arc surface, which can contact the convex part of the groove in the recessed portion 101. Figures 1 to 9In the examples shown, the number of grooves is two, and the cross-sectional shape of the base body 10 is circular. In some other embodiments, the number of grooves may be more than two, and they are arranged sequentially from the center of the circle along the radial direction Y of the base body 10 from the inside to the outside; the cross-sectional shape of the base body 10 may also be a rectangle, trapezoid or other irregular shapes. Those skilled in the art may configure this according to actual conditions, and this embodiment does not limit this.

[0042] As an optional embodiment, the epitaxial base may further include a boss 20 and a heating unit 40. The boss 20 is disposed on the carrier 100 and protrudes outward. The protruding distance of the boss 20 matches the protruding distance of the wafer 30 relative to the carrier 100. The boss 20 is used to optimize the horizontal gas flow field of the process gas during the epitaxial growth process. The side wall of the boss 20 may also be provided with an outlet hole to further optimize the gas flow field. The cross-sectional shape of the boss 20 may be as follows: Figure 2 The rectangle shown may also be a trapezoid or other irregular shapes; the boss 20 is arranged along the circumferential direction X of the base body 10 and is an annular component. The heating unit 40 may be an infrared lamp, which may be arranged on both sides of the base body along its own axial direction Z at the same time; and according to the different power distribution of the heating on both sides, the effect at the groove is also different. If the heating power of the upper surface of the base body (the side of the base body close to the chip 30) is high, the temperature of the chip 30 is higher than the temperature of the base body, then in the groove area, the heat is not easily transferred from the chip 30 to the base body, and the temperature of the chip 30 near the groove area will be higher than the temperature of the chip 30 in other areas; if the heating power of the lower surface of the base body (the side of the base body away from the chip 30) is high, the heat will be transferred from the base body to the chip 30, and in the groove area, the heat is not easily transferred from the base body to the chip 30, and the temperature of the chip 30 near the groove area will be lower than the temperature of the chip 30 in other areas.

[0043] In this configuration, by setting at least two grooves on the recessed portion 101, the grooves are set along the circumferential direction X of the base body 10, and at least two grooves are arranged along the radial direction Y of the base body 10, so that the side of the base body 10 close to the chip 30 forms a concave-convex appearance, and the thermal conductivity and gas characteristics at the grooves are different from those in other areas, resulting in a change in the temperature distribution in the groove area, causing changes in the heating and heat transfer on the back side of the chip 30, thereby changing the temperature of the surface of the chip 30, causing a change in the deposition rate, so as to compensate for the change in the deposition rate caused by other hardware or airflow. Appropriate compensation can improve the flatness and thickness uniformity of the epitaxial wafer 30.

[0044] Furthermore, the side wall of the groove is an inclined surface or a curved surface. Figures 1 to 9In the illustrated embodiment, the side walls of the grooves are all curved surfaces. With this configuration, when the back side of the chip 30 is deformed by heat and contacts the connection between adjacent grooves, it can be ensured that the back side of the chip 30 will not be damaged by scratches, thereby further improving the quality of the chip 30. Of course, in other embodiments, the side walls of the grooves may also be inclined surfaces. In this case, the connection between adjacent grooves will form a sharp top angle, and a smooth chamfer may be formed at the top angle to avoid damage to the back side of the chip 30.

[0045] Furthermore, the grooves are symmetrically arranged along the radial direction Y of the base body 10. Figures 1 to 9 In the illustrated examples, the grooves are symmetrically arranged along the radial direction Y of the base body 10, that is, the opening width of the groove (that is, the distance between the two side walls of the groove along the radial direction Y of the base body 10) is equal everywhere in the circumferential direction X of the base body 10. In other embodiments, the opening width of the groove may also vary in the circumferential direction X of the base body 10, and may be gradually increased or gradually decreased, or may be partially increased and partially decreased, and this embodiment does not impose any limitation on this.

[0046] Please refer to Figures 1 to 4 as well as Fig. 9 , the cross-sectional shape of the base body 10 in the direction parallel to the bearing surface is circular, the recessed portion 101 includes a first groove 1011 and a second groove 1012, the lowest point of the first groove 1011 in the axial direction Z of the base body 10 coincides with the center of the circle, and the second groove 1012 is located outside the first groove 1011 in the radial direction Y of the base body 10. It should be noted that the lowest point of the first groove 1011 in the axial direction Z of the base body 10 refers to the point in the first groove 1011 that is the farthest from the plane where the bearing platform 100 is located. The second groove 1012 can be arranged in sequence with the first groove 1011 along the radial direction Y of the base body 10 (refer to Figure 2 ), and can also be arranged in a radial direction Y of the base body 10 and spaced apart from the first groove 1011 (see Figure 4 ). The connection between the first groove 1011 and the second groove 1012 may be an arc surface (such as Figure 2 As shown, the first groove 1011 and the second groove 1012 are arranged in sequence and transitioned in a gentle arc), or they can be flat (as shown in FIG. Figure 4 as shown) or an inclined surface (as Fig. 9 Those skilled in the art may configure this according to actual conditions, and this embodiment does not limit this.

[0047] Furthermore, the distance between the first groove 1011 and the center of the circle along the radial direction Y of the base body 10 is between 20mm and 40mm; the depth of the first groove 1011 in the axial direction Z of the base body 10 is between 0.1mm and 1.5mm; the minimum distance between the second groove 1012 and the center of the circle along the radial direction Y of the base body 10 is between 50mm and 80mm; the maximum distance between the second groove 1012 and the center of the circle along the radial direction Y of the base body 10 is between 110mm and 140mm; the depth of the second groove 1012 in the axial direction Z of the base body 10 is between 0.1mm and 1.5mm. It should be noted that Figure 2 , Figure 4 as well as Fig. 9 In the illustrated example, the distance between the first groove 1011 and the center of the circle along the radial direction Y of the base body 10 is R1, the depth of the first groove 1011 in the axial direction Z of the base body 10 is H1, the minimum distance between the second groove 1012 and the center of the circle along the radial direction Y of the base body 10 is R21, the maximum distance between the second groove 1012 and the center of the circle along the radial direction Y of the base body 10 is R22, and the depth of the second groove 1012 in the axial direction Z of the base body 10 is H2. In the present embodiment, R1<R21<R22, so that the first groove 1011 is located on the inner side of the second groove 1012 in the radial direction Y of the base body 10, and H1<H2, so that the first groove 1011 and the second groove 1012 are concave in the radial direction Y of the base body 10. In other embodiments, the size relationship between R1, R21, R22 and H1 and H2 may also be in other forms, and those skilled in the art may configure this according to actual conditions.

[0048] Please refer to Figures 5 to 8 As another optional embodiment, the cross-sectional shape of the base body 10 in a direction parallel to the bearing surface is circular, and the recessed portion 101 includes a third groove 1013 and a fourth groove 1014. The lowest point of the third groove 1013 in the axial direction Z of the base body 10 does not coincide with the center of the circle, and the fourth groove 1014 is located on the outside of the third groove 1013 in the radial direction Y of the base body 10. It should be noted that the lowest point of the third groove 1013 in the axial direction Z of the base body 10 refers to the point in the third groove 1013 that is the farthest away from the plane where the bearing platform 100 is located. The fourth groove 1014 can be arranged in sequence with the third groove 1013 along the radial direction Y of the base body 10 (refer to Figure 6 ), and can also be arranged in a radial direction Y of the base body 10 and spaced apart from the third groove 1013 (see Figure 8 ). The connection between the third groove 1013 and the fourth groove 1014 may be an arc surface (such as Figure 6 As shown, the third groove 1013 and the fourth groove 1014 are arranged in sequence and transitioned in a gentle arc), or they can be flat (as shown in FIG. Figure 8Those skilled in the art may configure this according to actual conditions, and this embodiment does not limit this.

[0049] Furthermore, the minimum distance of the third groove 1013 from the center of the circle along the radial direction Y of the base body 10 is between 10mm and 40mm; the maximum distance of the third groove 1013 from the center of the circle along the radial direction Y of the base body 10 is between 40mm and 110mm; the depth of the third groove 1013 in the axial direction Z of the base body is between 0.1mm and 1.5mm; the minimum distance of the fourth groove 1014 from the center of the circle along the radial direction Y of the base body 10 is between 70mm and 120mm; the maximum distance of the fourth groove 1014 from the center of the circle along the radial direction Y of the base body 10 is between 120mm and 150mm; the depth of the third groove 1013 in the axial direction Z of the base body is between 0.1mm and 1.5mm. It should be noted that Figure 6 as well as Figure 8 In the illustrated example, the minimum distance between the third groove 1013 and the center of the circle along the radial direction Y of the base body 10 is R31, the maximum distance between the third groove 1013 and the center of the circle along the radial direction Y of the base body 10 is R32, the depth of the third groove 1013 in the axial direction Z of the base body 10 is H3, the minimum distance between the fourth groove 1014 and the center of the circle along the radial direction Y of the base body 10 is R41, the maximum distance between the fourth groove 1014 and the center of the circle along the radial direction Y of the base body 10 is R42, and the depth of the fourth groove 1014 in the axial direction Z of the base body 10 is H3. The depth in the axial direction Z is H4. In the present embodiment, R31<R32<R41<R42, so that the third groove 1013 is located on the inner side of the fourth groove 1014 in the radial direction Y of the base body 10, and H3>H4, so that the third groove 1013 and the fourth groove 1014 are concave along the radial direction Y of the base body 10. In other embodiments, the size relationship of R31, R32, R41, R42 and H3, H4 may also be in other forms, and those skilled in the art may configure this according to actual conditions.

[0050] Please refer to Figure 3 to Figure 4 , Figures 7 to 9 , a connecting platform 102 is provided between two adjacent grooves in the radial direction Y of the base body, and the connecting platform 102 is arranged along the circumferential direction X of the base body. Furthermore, the angle between the plane where the connecting platform 102 is located and the plane where the supporting platform 100 is located is α, then 0°≤α<90° and 90°<α≤180°. It should be noted that the connecting platform 102 is in a circular ring shape in this embodiment, and in some other embodiments, the connecting platform 102 may also be in other shapes, or the connecting platform 102 may also be a sporadic segment structure; Fig. 9In the illustrated example, the connection platform 102 may also be tilted. Of course, at the sharp corners produced by the tilted setting, smooth chamfers may be provided to reduce damage to the back side of the wafer 30 .

[0051] In another embodiment, the utility model also provides an epitaxial device, including the epitaxial base as described above. With such configuration, by using the epitaxial base with grooves, the side of the base body 10 close to the wafer 30 forms a concave-convex appearance, and the thermal conductivity and gas properties at the groove are different from those in other areas, resulting in a change in the temperature distribution in the groove area, causing changes in the heating and heat transfer on the back of the wafer 30, thereby changing the temperature of the surface of the wafer 30, causing a change in the deposition rate, so as to compensate for the change in the deposition rate caused by other hardware or airflow. Appropriate compensation can improve the flatness and thickness uniformity of the epitaxy of the wafer 30, thereby improving the yield of the wafer 30 produced by the epitaxial device.

[0052] In summary, in the epitaxial base and epitaxial equipment provided in the embodiments of the utility model, the epitaxial base includes: a base body; the base body includes a carrying platform and a recessed portion, the carrying platform is arranged at the edge of the base body, the carrying platform is connected to the recessed portion to form a carrying surface for carrying a wafer, the recessed portion is concave relative to the carrying platform in a direction away from the wafer, the wafer is placed on the carrying platform, and the wafer contacts the recessed portion during the epitaxial process; the recessed portion is provided with at least two grooves, the grooves are arranged along the circumference of the base body, and at least two grooves are arranged along the radial direction of the base body.

[0053] In this configuration, at least two grooves are provided on the recessed portion, the grooves are provided along the circumference of the base body, and at least two grooves are arranged along the radial direction of the base body, so that a concave-convex appearance is formed on the side of the base body close to the wafer, and the thermal conductivity and gas properties at the grooves are different from those in other areas, resulting in a change in the temperature distribution in the groove area, causing changes in the heating and heat transfer on the back of the wafer, thereby changing the temperature of the wafer surface, causing a change in the deposition rate, so as to compensate for changes in the deposition rate caused by other hardware or airflow. Appropriate compensation can improve the flatness and thickness uniformity of the wafer epitaxy.

[0054] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. An epitaxial base, characterized in that: include: Base body; The base body includes a carrier platform and a recessed portion, wherein the carrier platform is arranged at the edge of the base body, the carrier platform is connected to the recessed portion to form a carrier surface for carrying a wafer, the recessed portion is concave relative to the carrier platform in a direction away from the wafer, the wafer is placed on the carrier platform, and the wafer can contact the recessed portion during the epitaxial process; The recessed portion is provided with at least two grooves, the grooves are arranged along the circumference of the base body, and at least two of the grooves are arranged along the radial direction of the base body.

2. The epitaxial susceptor according to claim 1, characterized in that: The side wall of the groove is an inclined surface or a curved surface.

3. The epitaxial susceptor according to claim 2, characterized in that: The grooves are symmetrically arranged along the radial direction of the base body.

4. The epitaxial susceptor according to claim 3, characterized in that: The cross-sectional shape of the base body in a direction parallel to the bearing surface is circular, and the recessed portion includes a first groove and a second groove, wherein the lowest point of the first groove in the axial direction of the base body coincides with the center of the circle, and the second groove is located on the outside of the first groove in the radial direction of the base body.

5. The epitaxial susceptor according to claim 4, characterized in that: The distance between the first groove and the center of the circle along the radial direction of the base body is between 20 mm and 40 mm; the depth of the first groove in the axial direction of the base body is between 0.1 mm and 1.5 mm; The minimum distance of the second groove from the center of the circle along the radial direction of the base body is between 50mm and 80mm; the maximum distance of the second groove from the center of the circle along the radial direction of the base body is between 110mm and 140mm; the depth of the second groove in the axial direction of the base body is between 0.1mm and 1.5mm.

6. The epitaxial susceptor according to claim 3, characterized in that: The cross-sectional shape of the base body in a direction parallel to the bearing surface is circular, the recessed portion includes a third groove and a fourth groove, the lowest point of the third groove in the axial direction of the base body does not coincide with the center of the circle, and the fourth groove is located on the outside of the third groove in the radial direction of the base body.

7. The epitaxial susceptor according to claim 6, characterized in that: The minimum distance of the third groove from the center of the circle along the radial direction of the base body is between 10 mm and 40 mm; the maximum distance of the third groove from the center of the circle along the radial direction of the base body is between 40 mm and 110 mm; the depth of the third groove in the axial direction of the base body is between 0.1 mm and 1.5 mm; The minimum distance of the fourth groove from the center of the circle along the radial direction of the base body is between 70mm and 120mm; the maximum distance of the fourth groove from the center of the circle along the radial direction of the base body is between 120mm and 150mm; the depth of the third groove in the axial direction of the base body is between 0.1mm and 1.5mm.

8. The epitaxial susceptor according to claim 1, characterized in that: A connecting platform is provided between two adjacent grooves in the radial direction of the base body, and the connecting platform is arranged along the circumferential direction of the base body.

9. The epitaxial susceptor according to claim 8, characterized in that: The angle between the plane where the connecting platform is located and the plane where the supporting platform is located is α, then 0°≤α<90° and 90°<α≤180°.

10. An epitaxial device comprising the epitaxial susceptor according to any one of claims 1 to 9.

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