Vapor phase growth equipment

Abstract

The invention provides vapor phase growth equipment. The vapor phase growth equipment comprises a reaction chamber, a substrate holding device, a gas injection device and a rotation driving device, wherein the substrate holding and bearing device is provided with a plurality of recesses for bearing substrates, arc-shaped grooves are formed in the edges of the recesses, when the substrates are placed on the bearing surfaces of the recesses, part of the edges of the substrates are suspended above the arc-shaped grooves, and when the rotary driving device drives the substrate holding device to rotate, the arc-shaped grooves are separated from the arc-shaped grooves. According to the substrate holding device, the arc-shaped grooves are formed in the windward sides of the recesses, and the internal bearing surfaces and the edge bearing surfaces jointly bear the substrate, so that the adverse effect of the side walls of the recesses on the overhigh temperature of the edge parts of the substrate can be reduced, and the yield of the substrate is improved. And meanwhile, the substrate is subjected to temperature compensation by utilizing heat transfer of the side wall of the recess on the leeward side, so that the temperature uniformity of the substrate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices and apparatuses, and in particular to a vapor phase growth device. Background Art

[0002] The reaction chamber is a crucial chamber in the semiconductor device manufacturing process, in which the reaction chamber of the vapor phase growth equipment is brought in by gas to bring in reactants and establish a flow field. For example, in the reaction chamber that grows materials by vapor phase reaction, during the process growth, the delivery of gas source materials and the removal of byproducts after the growth reaction are completed by the reaction chamber flow field established by the carrier gas and the reactant gas.

[0003] For the reaction chamber that grows materials through gas phase reaction, the control of the temperature field in the reaction chamber is an important factor affecting the gas phase reaction. In order to increase production capacity, multiple substrates are usually laid flat in the reaction chamber for simultaneous deposition reaction. Therefore, the volume of the reaction chamber is required to be large enough; the larger the volume of the reaction chamber, the more difficult it is for the temperature in the reaction chamber to meet the reaction requirements, which will affect the uniformity of the grown epitaxial layer and the quality of the single crystal film. As a result, the yield of epitaxial growth is reduced and the production efficiency is reduced.

[0004] For semiconductor films with high film quality requirements, such as InGaAsP epitaxial wafers, they are highly dependent on temperature and require precise temperature control to ensure the quality of epitaxial film formation. In addition, differences in gas flow and temperature at different locations on the substrate surface can cause differences in the characteristics of the resulting semiconductor wafers, resulting in defective products. Summary of the invention

[0005] In view of the above-mentioned defects of the vapor phase growth equipment in the prior art, the present invention provides a vapor phase growth equipment to solve one or more of the above-mentioned problems.

[0006] In order to achieve the above object, the present invention provides a vapor phase growth device, comprising: a reaction chamber; A substrate holding device is arranged in the reaction chamber, a top surface of the substrate holding device is provided with a plurality of recesses along the same circumferential direction to form a recess group, and an arc groove is provided at the edge of each recess; A gas injection device, disposed in the reaction chamber and arranged opposite to the top surface of the substrate holding device, to provide process gas; A rotation driving device, which is dynamically sealed and disposed in the reaction chamber and fixedly connected to the substrate holding device, so as to drive the substrate holding device to rotate around the central axis of the top surface of the substrate holding device; Wherein, the recess comprises an internal bearing surface and an edge bearing surface whose top surfaces are flush and connected, the arc groove surrounds the internal bearing surface, and the edge bearing surface is located between the two ends of the arc groove, so that the placed substrate is supported by the internal bearing surface and the edge bearing surface, and part of the edge of the substrate is suspended above the arc groove; in the process of the substrate holding device driven by the rotary driving device to rotate, the process gas forms a rotating airflow on the top surface of the substrate holding device, and the area where the edge bearing surface of each recess is located faces away from the incoming flow direction of the rotating airflow, and the flow direction of the rotating airflow is opposite to the rotation direction of the substrate holding device.

[0007] Optionally, the number of the recess groups is at least 2, and they are arranged sequentially from the inside to the outside around the rotation center O of the substrate holding device, the number of recesses in the recess groups is at least 3, and among adjacent recess groups, the number of recesses in the inner circle recess group close to the middle of the substrate holding device is less than the number of recesses in the outer circle recess group away from the middle of the substrate holding device.

[0008] Optionally, the top surface opening of the arc groove includes a first end and a second end opposite to each other, and a first acute angle a between a first line connecting the first end and the center O′ of the recess where the arc groove is located and a second line connecting the second end and the center O′ of the recess where the arc groove is located is 85°~95°.

[0009] Optionally, the second end is closer to the rotation center O of the substrate holding device than the first end, and an angle β between a third line connecting the rotation center O of the substrate holding device and the center O′ of the recess where the arc groove is located and the second line is 40°~70°.

[0010] Optionally, the number of the recess groups is at least 2 and they are arranged sequentially from the inside to the outside around the rotation center O of the substrate holding device, and the angles β of the recesses in the same recess group are consistent, and the first acute angles a are consistent.

[0011] Optionally, in adjacent groups of recesses, the angle β of each recess in the inner circle recess group close to the rotation center O of the substrate holding device is smaller than the angle β of each recess in the outer circle recess group far from the rotation center O of the substrate holding device; in the recess group closest to the rotation center O of the substrate holding device, the angle β of each recess is 40°~50°.

[0012] Optionally, the number of the recess groups is at least N, and they are arranged sequentially from the inside to the outside around the center of the substrate holding device, N is a positive integer greater than or equal to 2, and the number of recesses in the same recess group is at least 3; When N is less than or equal to 3, among the adjacent recess groups, the duty ratio of the inner recess group close to the center of the substrate holding device is smaller than the duty ratio of the outer recess group far from the center of the substrate holding device; When N is greater than 3, from the (N-1)th recess group to the Nth recess group from the inside to the outside, the duty ratios of adjacent recess groups are consistent.

[0013] Optionally, the duty cycle of the recess group closest to the center of the substrate holding device is 50% to 55%, and the duty cycle of the recess group farthest from the center of the substrate holding device does not exceed 75%.

[0014] Optionally, in the same recess group, the recesses are evenly arranged around the rotation axis of the substrate holding device, the recesses have the same structure, and the arc grooves of the recesses have the same structure.

[0015] Optionally, the radial width of the top surface opening of the arc-shaped groove does not exceed 10% of the radial length of the area surrounded by the edge of the bottom surface of the recess.

[0016] Optionally, the opening of the arc-shaped groove is in a fan-shaped shape, and the center of the fan-shaped groove coincides with the center of the recess.

[0017] Optionally, the side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc-shaped groove is inclined to the top surface of the internal bearing surface, so that the top outer diameter of the structure surrounded by the internal bearing surface and the side wall is smaller than the bottom outer diameter.

[0018] Optionally, the side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc-shaped groove is a stepped side wall, or an outwardly convex arc-shaped side wall.

[0019] Optionally, the top surface of the substrate holding device includes a non-load-bearing surface surrounding the recess, and a chamfered surface is provided between the non-load-bearing surface and the side wall of the recess, wherein the height of the chamfered surface is not lower than the height of the substrate carried in the recess, and the height of the chamfered surface relative to the top surface of the substrate does not exceed 5% of the depth of the arc groove.

[0020] Optionally, the chamfered surface is covered with a thermal conductive coating, and the thermal conductivity of the thermal conductive coating is lower than the thermal conductivity of the non-load-bearing surface.

[0021] Optionally, the top surface of the substrate holding device includes a non-bearing surface surrounding the recess, and the inner wall of the arc groove connecting the non-bearing surface is covered with a thermal conductive coating, and the thermal conductivity of the thermal conductive coating is lower than the thermal conductivity of the non-bearing surface.

[0022] Optionally, the number of the recess groups is at least N, and they are arranged sequentially from the inside to the outside around the center of the substrate holding device, N is a positive integer greater than or equal to 2, and in adjacent recess groups: The number of the recesses in the inner circle recess group close to the rotation center O of the substrate holding device is less than the number of the recesses in the outer circle recess group far from the rotation center O of the substrate holding device; The inner circle recess group includes a first recess, the outer circle recess group includes a second recess and a third recess that are adjacent to each other and adjacent to the first recess, and an extension line of a line between a rotation center O of the substrate holding device and a center of the first recess passes between the second recess and the third recess.

[0023] As described above, the vapor phase growth device of the present invention has the following beneficial effects:

[0024] The substrate holding device in the vapor phase growth device of the present invention is provided with a plurality of recesses for carrying substrates, and the edges of the recesses are provided with arc grooves. When the substrate is placed on the carrying surface of the recess, part of the edge of the substrate is suspended above the arc groove. In the process of the substrate holding device driven to rotate by the rotation driving device, the area where the edge carrying surface of each recess is located faces away from the flow direction of the rotating airflow formed by the process gas on the top surface of the substrate holding device. Since the temperature of the airflow increases when it flows through the substrate holding surface, the airflow temperature gradually decreases in the process of flowing through the relatively low temperature substrate, and an arc groove is formed on the windward side of the recess. The internal carrying surface and the edge carrying surface jointly carry the substrate, which can reduce the adverse effect of the side wall of the recess on the overheating of the edge temperature of the substrate, and at the same time use the heat transfer of the side wall of the recess on the leeward side to compensate the temperature of the substrate, thereby improving the temperature uniformity of the substrate.

[0025] The temperature uniformity not only includes the edge and different internal areas of the same substrate, but also includes different substrates in different loading areas on the substrate holding device. Therefore, the substrate holding and supporting device of the present invention can not only improve the deposition uniformity on the same substrate, but also improve the deposition uniformity of the inner circle substrate and the outer circle substrate carried by the loading area. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a front cross-sectional schematic diagram of the vapor phase growth device provided by the present invention.

[0027] Figure 2 Display as Figure 1 Schematic diagram of the top view of the structure of the substrate holding device.

[0028] Figure 3 Display as Figure 2 Schematic diagram of the top view structure of the concave hole in.

[0029] Figure 4 Display as Figure 2 A schematic top view of the structure of the first recess group in FIG.

[0030] Figure 5 Display as Figure 3 Schematic diagram of the cross-sectional structure along the AA direction.

[0031] Figure 6 An alternative embodiment is shown Figure 5 Schematic diagram of the local enlarged structure of part B.

[0032] Figure 7 In another alternative embodiment, Figure 5 Schematic diagram of the local enlarged structure of part B.

[0033] Figure 8 The cavity in the vapor phase growth device provided as another alternative embodiment corresponds to Figure 5 Schematic diagram of the local enlarged structure of part B.

[0034] Fig. 9 It shows the surface fluorescence excitation spectrum of the substrate measured under predetermined process conditions when the top of the recess is flat and not grooved.

[0035] Fig.10 When the arc groove is set on the edge of the cavity, Fig. 9 Surface fluorescence excitation spectrum of the substrate measured under the same process conditions.

[0036] Fig.11 When an annular groove is set on the edge of the cavity, Fig. 9 Surface fluorescence excitation spectrum of the substrate measured under the same process conditions.

[0037] Component marking instructions

[0038] 1. substrate holding device; 11. top surface; 12. bottom surface; 100. recess; 100-1. first recess; 100-2. second recess; 100-3. third recess; 101. first recess group; 102. second recess group; 111. inner bearing surface; 112. edge bearing surface; 113. arc groove; 1131 first end; 1132. second end; 114. side wall; 114′, stepped side wall; 114′′, convex arc side wall; 115. chamfered surface; 116. thermal conductive coating; 200. substrate; 2. heating device; 3. rotation drive device; 4. gas injection mechanism; 5. reaction chamber. DETAILED DESCRIPTION

[0039] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0040] The present embodiment provides a vapor growth device, which may be, for example, a vapor deposition device, specifically, a chemical vapor deposition (CVD) device or a physical vapor deposition (PVD) device. The vapor deposition device 10 may be a plasma-enhanced chemical vapor deposition (PECVD) device, a metal-organic chemical vapor deposition (MOCVD) device, etc. The present embodiment is described by taking an MOCVD device as an example. It should be understood that the device is merely exemplary, and the present invention is not limited to this device.

[0041] like Figure 1 As shown, the vapor phase growth device of the present invention has a reaction chamber 5, in which a substrate holding device 1 for carrying a substrate 200 is arranged. The reaction chamber 5 is also provided with a gas injection device for providing process gas into the reaction chamber 5, and the gas injection device is arranged opposite to the substrate holding device 1. Specifically, the gas outlet side of the gas injection device is arranged opposite to the top surface 11 of the substrate holding device 1 for carrying the substrate 200. The bottom surface 12 of the substrate holding device 1 is also provided with a heating device 2, which can heat the substrate holding device 1 and heat the carried substrate 200 through heat transfer of the substrate holding device 1. As shown in FIG. Figure 1 As shown, the vapor phase growth equipment of the present invention also includes a rotation driving device 3, which is arranged in the reaction chamber 5 in a dynamic sealing manner and is fixedly connected to the middle part of the substrate holding device 1 to drive the substrate holding device 1 to rotate around the rotation axis T2 during the vapor phase reaction.

[0042] The cross section of the reaction chamber 5 of the vapor phase growth device is generally a circular or quasi-circular structure, or it can be a rectangular structure or other structures known to those skilled in the art, which will not be described in detail here. The reaction chamber 5 is a vertical flow chamber with vertical gas intake. The reaction chamber 5 can be a vertical chamber in which the gas injection mechanism 4 and the substrate holding device 1 are arranged opposite to each other, and the gas injection mechanism 4 is located at the upper part and the substrate holding device 1 is located at the lower part. Figure 1The cross section of the reaction chamber 5 shown is circular, and the gas injection mechanism 4 is located at the upper part and the substrate holding device 1 is located at the lower part. The gas injection mechanism 4 is described by taking an upright vertical flow chamber as an example.

[0043] Reference Figure 1 and Figure 2 The reaction chamber 5 is provided with a gas injection mechanism 4 for carrying the substrate 200 to be processed, which is arranged opposite to the substrate holding device 1, for example, arranged at the top of the reaction chamber 5, and injects gas into the reaction chamber 5, and the substrate holding device 1 is located below the gas injection mechanism 4. The gas injection mechanism 4 provided in this embodiment has a disc-shaped structure as a whole, wherein the gas outlet surface of the gas injection mechanism 4 faces the substrate holding device 1.

[0044] Also refer to Figure 1 As shown, a main axis T1 is defined, which is perpendicular to the outlet surface of the disc-shaped gas injection mechanism 4 and passes through the geometric center of the outlet surface of the gas injection mechanism 4. The main axis T1 may be parallel to the rotation axis T2 of the substrate holding device 1 or may not be parallel. Preferably, the main axis T1 is parallel to the rotation axis T2 of the substrate holding device 1 (that is, the central axis of the top surface of the substrate holding device 1). Preferably, the main axis T1 coincides with the rotation axis T2.

[0045] The top surface 11 of the substrate holding device 1 is provided with a plurality of recesses 100, which are formed by being recessed from the top surface 11 to the bottom surface 12 of the substrate holding device 1. The size and number of the recesses 100 and the distribution of the recesses 100 on the substrate holding device 1 can be designed according to the size, thickness, number of the substrates 200 to be carried and held and the size of the substrate holding device 1. For a substrate 200 that is generally disc-shaped, the recesses 100 are correspondingly designed as a structure with a circular opening, and the size of the opening is set corresponding to the size of the substrate 200.

[0046] In an optional embodiment, a plurality of recesses 100 are provided on the top surface 11 of the substrate holding device 1 along the same circumferential direction, and the plurality of recesses 100 on the circumferential direction form a recess group. The top surface 11 of the same substrate holding device 1 forms N recess groups, such as 2, 3 or more recess groups, along different circumferential directions from the inside to the outside at the rotation center of the substrate holding device 1. Each recess group includes a plurality of recesses 100, and further, each recess group includes at least 3 recesses 100. The geometric centers of the plurality of recesses 100 in the same recess group are located on the same circumference of the top surface 11 of the substrate holding device 1.

[0047] In an optional embodiment, among the adjacent recess groups, the number of recesses 100 in the inner circle recess group closer to the middle of the substrate holding device 1 is smaller than the number of recesses 100 in the outer circle recess group farther from the middle of the substrate holding device 1 .

[0048] In an optional embodiment, in the same recess group, a plurality of recesses 100 are evenly arranged along the rotation axis T2 of the substrate holding device 1 , that is, the intervals between adjacent recesses 100 are the same.

[0049] Embodiment 1

[0050] In the vapor growth apparatus of this embodiment, an example in which two recess groups are formed on the top surface 11 of the substrate holding device 1 is used for explanation. Figure 2 The schematic diagram of the top view of the substrate holding device 1 of this embodiment is shown. It should be understood that in the present invention, the so-called "looking up" refers to the viewing direction of observing along the bottom surface 12 of the substrate holding device 1 toward the top surface 11, and the "looking down" refers to the viewing direction of observing along the top surface 11 toward the bottom surface 12 of the substrate holding device 1.

[0051] like Figure 2 As shown, in this embodiment, a first recess group 101 and a second recess group 102 are formed on the top surface 11 of the substrate holding device 1 along two different circumferences, a first circumference C1 and a second circumference C2, and the diameter of the first circumference C1 is smaller than the diameter of the second circumference C2, that is, the first recess group 101 is closer to the rotation center O of the substrate holding device 1. Three recesses 100 are distributed in the first recess group 101, and nine recesses 100 are distributed in the second recess group 102.

[0052] In an optional embodiment, if Figure 2 As shown, the first recess group 101 close to the rotation center O of the substrate holding device 1 has a first recess 100-1, and the second recess group 102 far from the rotation center O of the substrate holding device 1 has a second recess 100-2 and a third recess 100-3, and the second recess 100-2 and the third recess 100-3 are adjacent to each other and adjacent to the first recess 100-1. The extension line of the line between the rotation center O of the substrate holding device 1 and the center O' of the first recess 100-1 passes between the second recess 100-2 and the third recess 100-3. As a result, the recesses 100 in the inner circle recess group and the outer circle recess group are staggered, which can optimize the distribution of the recesses 100 on the substrate holding device 1 and optimize the bearing area of ​​the top surface 11 of the substrate holding device 1.

[0053] In this embodiment, the cavity groups and duty cycles are defined as follows: Figure 2 As shown, taking the second recess group 102 (ie, the outer ring recess group) as an example, the plurality of recesses 100 of the recess group are distributed in the middle of the inner and outer tangent circles, that is, Figure 2The area of ​​the ring sandwiched between the third circumference C3 and the fourth circumference C4 is S, the top opening area of ​​each recess 100 in the second recess group 102 is S1, and the ratio of the sum of the top opening areas S1 of each recess 100 to the ring area S is the duty cycle of the second recess group 102. In an optional embodiment, it is defined that the top surface 11 of the substrate holding device 1 is provided with N recess groups, when N is less than or equal to 3, among adjacent recess groups, the duty cycle of the inner recess group close to the center O of the substrate holding device 1 is less than the duty cycle of the outer recess group far from the center O of the substrate holding device 1; when N is greater than 3, the duty cycles of adjacent recess groups from the third recess group to the Nth recess group from the inside to the outside are consistent. In a further optional embodiment, the duty cycle of the recess group closest to the center of the substrate holding device 1 is 50% to 55%, and the duty cycle of the recess group farthest from the center of the substrate holding device 1 does not exceed 75%. For example, in some specific embodiments, the size of the placed substrate 200 can be 2 inches or 3 inches, and the diameter of the substrate holding device 1 can be 380 mm. The opening diameter of each recess 100 can be slightly larger than 2 inches or slightly larger than 3 inches, or recesses 100 of two sizes can be opened on the same substrate holding device 1 at the same time. Taking the arrangement of two recess groups as an example, the inner circle recess group is provided with 3 recesses 100, and the outer circle recess group is provided with 9 recesses 100.

[0054] In order to ensure the efficiency of heat transfer to the substrate 200, the substrate holding device 1 is made of a material with high thermal conductivity, such as graphite. Under process conditions, the rotary drive device 3 drives the substrate holding device 1 to rotate around the central axis of its top surface, and the process gas sprayed onto the substrate 200 will be dragged by the rotation of the substrate holding device 1 to form a rotating airflow. Due to the different thermal conductivity of the substrate 200 and the substrate holding device 1, the temperature of the substrate holding device 1 is higher than the temperature of the substrate 200 due to the convection and radiation of the gas field and temperature field in the process environment. The process gas flows through the non-bearing surface of the substrate holding device 1 that does not bear the substrate 200 along the incoming flow direction and is heated. When it flows through the nearby substrate 200, it has a certain heating effect on the substrate 200, and this heating effect tends to weaken along the incoming flow direction, thereby exacerbating the unevenness of the temperature of the substrate 200. The duty cycle of each recess group is adjusted to increase, that is, the duty cycle of the recess group closest to the center of the substrate holding device 1 is 50% to 55%, and the duty cycle of the recess group farthest from the center of the substrate holding device 1 does not exceed 75% of the duty cycle, thereby compressing the area of ​​the non-load-bearing surface near the recess 100 to minimize the adverse effect of the process gas heated by the substrate holding device 1 on the temperature uniformity of the substrate.

[0055] In the embodiment of the present invention, the flow direction of the rotating airflow formed by the process gas is opposite to the rotation direction of the substrate holding device 1 .

[0056] In some specific embodiments, such as a MOCVD device for growing quaternary InGaAsP, the rotation speed of the substrate holding device 1 is controlled to be greater than or equal to 500 rpm, and the process temperature is above 600°C, such as 750°C, 1000°C.

[0057] When the substrate 200 is placed in the cavity 100, the gap between the edge of the substrate 200 and the edge of the cavity 100 is very small, and the side wall of the cavity 100 will generate heat transfer to the substrate 200, which will cause the edge temperature of the substrate 200 to increase significantly compared with the middle temperature, especially under the centrifugal force of the substrate holding device 1 driven by the rotation drive device 3, especially under the centrifugal force of the high-speed rotation as described above, part of the side wall of the substrate 200 will be closer to or even fit to the side wall of the cavity 100, and the above-mentioned temperature influence will be more significant. Specifically, an InP substrate is placed on the cavity with a flat bottom and no grooves, and a film is formed on the substrate under the process conditions of a process temperature of 650°C, a rotation speed of 500 rpm, a trimethylgallium flow rate of 80 sccm, an arsine flow rate of 50 sccm, a phosphine flow rate of 1000 sccm, and a trimethylindium flow rate of 800 sccm. The temperature of the film formed on the substrate is measured by a photoluminescence tester. Fig. 9 The surface fluorescence excitation spectrum shown in the figure shows that the red area is the long wavelength area and the blue area is the short wavelength area. The shorter the wavelength, the higher the temperature of the substrate surface. It can be seen that there is a significant temperature difference between the edge and the middle of the substrate on the concave with a flat bottom and no grooves, and the temperature uniformity is poor. In order to reduce the difference between the edge temperature of the substrate 200 and the middle temperature, the concave 100 of this embodiment has an arc groove 113 at the edge to reduce the contact area between the edge of the substrate 200 and the concave 100, weaken the influence of the heat transfer of the side wall of the concave 100 on the edge temperature of the substrate 200, and Fig. 9 Under the same process conditions, the surface fluorescence excitation spectrum measured is as follows Fig.10 As shown. Fig.10 It can be seen that when the arc groove 113 is opened at the edge of the cavity 100, the standard deviation Std Dev of the surface temperature of the substrate in the cavity 100 is significantly reduced.

[0058] like Figure 2 and Figure 3 As shown, in this embodiment, the cavity 100 includes an inner bearing surface 111 and an edge bearing surface 112 whose top surfaces are flush and connected. An arc groove 113 is opened downward from the top surface at the edge of the cavity 100. The arc groove 113 surrounds the inner bearing surface 111, and the edge bearing surface 112 is located between the two ends of the arc groove 113. Figure 2 and Figure 3 As shown, in this embodiment, the opening of the arc groove 113 in the cavity 100 is in the shape of a sector ring (i.e., a portion of a circular ring), and the center of the sector ring coincides with the center O′ of the cavity 100 in which it is located. Figure 3 As shown, the top opening of the arc groove 113 includes a first end 1131 and a second end 1132 opposite to each other, and the first acute angle a between the first end 1131 and the first connecting line L1 of the center O' of the cavity 100 and the second connecting line L2 of the second end 1132 and the center O' of the cavity 100 is 85° to 95°. The setting of this angle ensures the proportion of the arc groove 113 and the edge bearing surface 112, and ensures the uniformity of the temperature of the substrate 200 caused by the heat transfer of the cavity 100.

[0059] In an optional embodiment, if Figure 4 As shown, taking the inner circle recess group as an example, the second end 1132 of the arc groove 113 is closer to the rotation center O of the substrate holding device 1 than the first end 1131. The rotation center O of the substrate holding device 1 and the center O′ of the recess 100 where the arc groove 113 is located form a third line L3, and the angle β between the third line L3 and the second line L2 is 40° to 70°.

[0060] In a further optional embodiment, the number of recess groups on the top surface 11 of the substrate holding device 1 is at least 2 and they are arranged sequentially from the inside to the outside around the rotation center O of the substrate holding device 1, and the above-mentioned angle β of each recess 100 in the same recess group is consistent, and the first acute angle a is consistent.

[0061] In adjacent recess groups, the angle β of each recess 100 in the inner recess group close to the rotation center O of the substrate holding device 1 is smaller than the angle β of each recess 100 in the outer recess group far from the rotation center O of the substrate holding device 1; in the recess group closest to the rotation center O of the substrate holding device 1, the angle β of each recess 100 is 40°~50°. The setting of the above angle β limits the position of the arc groove (that is, the edge support surface) in each recess 100 relative to the rotation center O of the substrate holding device 1, ensuring that the arc groove is located on the windward side (high temperature side) of the process gas flow direction; at the same time, it also ensures the proportion of the arc groove 113 and the edge bearing surface 112, ensuring the uniformity of the temperature of the substrate 200 due to heat transfer of the recess 100.

[0062] When the substrate 200 is placed in the cavity 100, it is supported by the internal bearing surface 111 and the edge bearing surface 112 of the cavity 100, and part of the edge of the substrate 200 at the position of the arc groove 113 is suspended above the arc groove 113. During the vapor growth process, the rotary drive device 3 drives the substrate holding device 1 to rotate, and the area where the edge bearing surface 112 of each cavity 100 is located faces away from the flow direction of the process gas flow (that is, the flow direction points from the location of the arc groove 113 to the location of the edge bearing surface 112). The gas flow entering the reaction chamber 5 is heated when passing through the surface of the substrate holding device 1. Due to the different thermal conductivity of the substrate 200 and the substrate holding device 1, the temperature of the substrate 200 is lower than that of the substrate holding device 1. The heating effect of the process gas on the substrate 200 will be reduced when the process gas flows through the substrate 200, so that there will be a significant temperature difference between the area of ​​the substrate 200 away from the arc groove 113 and the area close to the arc groove 113. Fig.11 As shown, the recess 100 is provided with an annular groove, the width of which is designed to be consistent with the width of the arc groove 113. Fig. 9 Under the same process conditions, the surface fluorescence excitation spectrum measured is as follows Fig.11 As shown. Fig.11 It can be seen that when the arc groove 113 is formed at the edge of the cavity 100, the standard deviation Std Dev of the surface temperature of the substrate in the cavity 100 is higher than Fig.10 The Std Dev value of the substrate temperature field distribution uniformity is lower than Fig.10 The temperature of the substrate shown is uniform. Therefore, as described above, the leeward side of the cavity 100 is not grooved, and an arc groove 113 is formed on the windward side of the cavity 100. Accordingly, the substrate 200 in the corresponding area of ​​the leeward side is supported by the inner bearing surface 111 and the edge bearing surface 112 of the cavity 100, so the temperature of the substrate 200 can be compensated by heat transfer from the side wall of the cavity 100 on the leeward side, thereby reducing the temperature difference between the middle and edge of the substrate 200, and the windward and leeward sides.

[0063] In an optional embodiment, in the same recess group, each recess 100 is evenly arranged around the rotation axis T2 of the substrate holding device 1, each recess 100 has the same structure, and the arc groove 113 of each recess 100 also has the same structure. In an optional embodiment, in adjacent recesses 100 in the same recess group, the opening of the arc groove 113 of one recess 100 is located at a first position relative to the gas injection device, and the opening of the arc groove 113 of another recess 100 is located at a second position relative to the gas injection device. Specifically, taking the disc-shaped gas injection device as an example, in Figure 1In the top-down view shown in the figure, the first position and the second position are two adjacent positions on the same circumference on the projection of the gas injection device. And the first position and the second position cover two adjacent recesses 100 in the same recess group on the top surface 11 of the substrate holding device 1. During the process of the substrate holding device 1 being driven to rotate by the rotation drive device 3, the arc groove 113 of one recess 100 is transferred from the first position to the second position relative to the gas injection device. Figure 2 For example, the arc groove 113 of the second recess 100-2 in the second recess group 102 is located at the first position, and the arc groove 113 of the third recess 100-3 is located at the second position. When the rotary drive device 3 drives the substrate holding device 1 to rotate, at a certain moment, the arc groove 113 of the second recess 100-2 is transferred to the second position.

[0064] In an optional embodiment, the radial width of the top surface opening of the arc groove 113 (i.e., the radial distance difference between the inner and outer arc lines of the arc groove 113) does not exceed 10% of the radial length of the area surrounded by the bottom edge of the cavity 100. For example, for the cavity 100 for placing a 2-inch or 3-inch wafer, the radial width of the top surface opening of the arc groove 113 is at most 7 mm. If the radial width of the top surface opening of the arc groove 113 is too large, the area of ​​the bonding surface for supporting the wafer is reduced, and the portion directly in contact with the substrate 200 for heat transfer is reduced, which is not conducive to temperature uniformity.

[0065] Embodiment 2

[0066] This embodiment also provides a vapor phase growth device. In this embodiment, Figure 5 As shown, the side wall 114 formed between the top surface of the internal bearing surface 111 of the cavity 100 and the bottom surface of the arc groove 113 is inclined to the top surface of the internal bearing surface 111, thereby making the top outer diameter R1 of the structure surrounded by the internal bearing surface 111 and the side wall 114 smaller than the bottom outer diameter R1. Since the airflow is heated to a higher temperature when it flows through the non-bearing surface, and then the process of flowing through the substrate aggravates the temperature non-uniformity of the substrate (for specific reasons, please refer to the relevant analysis of the first embodiment), the inclined side wall 114 can be set to compensate the heat transfer temperature field of the top surface of the substrate 200 through the cavity side wall 114 and the bottom of the cavity 100, which is beneficial to the temperature uniformity of the substrate 200.

[0067] In an alternative embodiment, if Figure 6 As shown in FIG. 1 , the side wall formed between the top surface of the internal bearing surface 111 and the bottom surface of the arc groove 113 is a stepped side wall 114'. For example, it may include two or more steps. Figure 6 As shown, in this embodiment, the stepped side wall 114 ′ includes three steps, the height of each step can be the same or different, and the width of each step in the radial direction of the cavity 100 can be the same or different.

[0068] In some optional embodiments, the step height increases sequentially along the direction from the edge of the cavity 100 toward the middle, and the incremental trend decreases sequentially, and the step becomes flatter as it approaches the middle of the cavity 100 .

[0069] In another optional embodiment, if Figure 7 As shown, the side wall formed between the top surface of the internal bearing surface 111 and the bottom surface of the arc groove 113 is an arc side wall, and further, the arc side wall is an outwardly convex arc side wall 114 ″ protruding along the internal bearing surface 111 toward the arc groove.

[0070] Embodiment 3

[0071] This embodiment also provides a vapor phase growth device. In this embodiment, Figure 8 As shown, the top surface 11 of the substrate holding device 1 surrounding the cavity 100 is a non-load-bearing surface, and a chamfered surface 115 is formed between the non-load-bearing surface and the side wall of the cavity 100. The height of the chamfered surface 115 is not lower than the height of the substrate 200 carried in the cavity 100. The chamfered surface 115 can be, for example, an arc surface or a similar inclined surface. Figure 8 As shown, the height H of the chamfered surface 115 relative to the top surface of the substrate 200 does not exceed 5% of the depth D of the arc groove 113. In an optional embodiment, the height H of the chamfered surface 115 relative to the top surface of the substrate 200 is within the range of 5% (1±30%) of the depth D of the arc groove 113. In a certain example, for example, the depth D of the arc groove 113 = 675 microns, and the height H of the chamfered surface 115 relative to the top surface of the substrate 200 = 25 microns.

[0072] In a further optional embodiment, if Figure 8 As shown, the chamfered surface 115 is covered with a thermal conductive coating 116 , the thermal conductivity of the thermal conductive coating 116 is lower than the thermal conductivity of the non-bearing surface, thereby appropriately reducing the heat transfer from the substrate holding device 1 to the edge of the substrate 200 in the cavity 100 .

[0073] In another optional embodiment, the inner wall of the arc groove 113 of the arc groove 113 connected to the non-bearing surface is also covered with a thermal conductive coating 116. Further, as Figure 8 The inner wall and chamfered surface 115 of the arc-shaped groove 113 are covered with a thermal conductive layer, and the thermal conductive layer forms a continuous structure on the inner part and the chamfered surface 115. The thermal conductivity of the thermal conductive coating 116 is lower than that of the non-load-bearing surface, which can appropriately reduce the heat transfer from the non-load-bearing surface of the substrate holding device 1 to the edge of the substrate 200 in the cavity 100, which is beneficial to the temperature uniformity of the substrate 200.

[0074] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A vapor phase growth device, characterized in that: include: a reaction chamber; A substrate holding device is arranged in the reaction chamber, a top surface of the substrate holding device is provided with a plurality of recesses along the same circumferential direction to form a recess group, and an arc groove is provided at the edge of each recess; A gas injection device, disposed in the reaction chamber and arranged opposite to the top surface of the substrate holding device, to provide process gas; A rotation driving device, which is dynamically sealed and disposed in the reaction chamber and fixedly connected to the substrate holding device, so as to drive the substrate holding device to rotate around the central axis of the top surface of the substrate holding device; Wherein, the recess comprises an internal bearing surface and an edge bearing surface whose top surfaces are flush and connected, the arc groove surrounds the internal bearing surface, and the edge bearing surface is located between the two ends of the arc groove, so that the placed substrate is supported by the internal bearing surface and the edge bearing surface, and part of the edge of the substrate is suspended above the arc groove; in the process of the substrate holding device driven by the rotary driving device to rotate, the process gas forms a rotating airflow on the top surface of the substrate holding device, and the area where the edge bearing surface of each recess is located faces away from the incoming flow direction of the rotating airflow, and the flow direction of the rotating airflow is opposite to the rotation direction of the substrate holding device.

2. The vapor growth apparatus according to claim 1, characterized in that: The number of the recess groups is at least 2, and they are arranged sequentially from the inside to the outside around the rotation center O of the substrate holding device. The number of recesses in the recess groups is at least 3. Among adjacent recess groups, the number of recesses in the inner circle recess group close to the middle of the substrate holding device is less than the number of recesses in the outer circle recess group far from the middle of the substrate holding device.

3. The vapor phase growth apparatus according to claim 1, characterized in that: The top surface opening of the arc groove includes a first end and a second end opposite to each other, and a first acute angle a between a first line connecting the first end and the center O' of the recess where the arc groove is located and a second line connecting the second end and the center O' of the recess where the arc groove is located is 85°~95°.

4. The vapor phase growth apparatus according to claim 3, characterized in that: The second end is closer to the rotation center O of the substrate holding device than the first end, and an angle β between a third line connecting the rotation center O of the substrate holding device and the center O′ of the recess where the arc groove is located and the second line is 40°~70°.

5. The vapor phase growth apparatus according to claim 4, characterized in that: The number of the recess groups is at least 2 and they are arranged sequentially from the inside to the outside around the rotation center O of the substrate holding device. The angles β of the recesses in the same recess group are consistent, and the first acute angles a are consistent.

6. The vapor phase growth apparatus according to claim 4, characterized in that: Among the adjacent recess groups, the angle β of each recess in the inner recess group close to the rotation center O of the substrate holding device is smaller than the angle β of each recess in the outer recess group far from the rotation center O of the substrate holding device; In the recess group closest to the rotation center O of the substrate holding device, the angle β of each recess is 40°~50°.

7. The vapor phase growth apparatus according to claim 1, characterized in that: The number of the recess groups is at least N, and they are arranged sequentially from the inside to the outside around the center of the substrate holding device, N is a positive integer greater than or equal to 2, and the number of recesses in the same recess group is at least 3; When N is less than or equal to 3, among the adjacent recess groups, the duty ratio of the inner recess group close to the center of the substrate holding device is smaller than the duty ratio of the outer recess group far from the center of the substrate holding device; When N is greater than 3, the duty ratios of adjacent recess groups from the third recess group to the Nth recess group from the inside to the outside are consistent.

8. The vapor phase growth apparatus according to claim 1, wherein: The duty cycle of the recess group closest to the center of the substrate holding device is 50% to 55%, and the duty cycle of the recess group farthest from the center of the substrate holding device does not exceed 75%.

9. The vapor phase growth apparatus according to claim 1, characterized in that: In the same recess group, the recesses are evenly arranged around the rotation axis of the substrate holding device, the recesses have the same structure, and the arc grooves of the recesses have the same structure.

10. The vapor growth apparatus according to claim 1, characterized in that: The radial width of the top opening of the arc-shaped groove does not exceed 10% of the radial length of the area surrounded by the edge of the bottom surface of the recess.

11. The vapor phase growth apparatus according to claim 1, characterized in that: The opening of the arc-shaped groove is in a sector ring shape, and the center of the sector ring coincides with the center of the recess.

12. The vapor phase growth apparatus according to claim 1, characterized in that: The side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc-shaped groove is inclined to the top surface of the internal bearing surface, so that the top outer diameter of the structure surrounded by the internal bearing surface and the side wall is smaller than the bottom outer diameter.

13. The vapor phase growth apparatus according to claim 12, characterized in that: The side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc-shaped groove is a stepped side wall, or an outwardly convex arc-shaped side wall.

14. The vapor growth apparatus according to claim 1, characterized in that: The top surface of the substrate holding device includes a non-load-bearing surface surrounding the recess, and a chamfered surface is formed between the non-load-bearing surface and the side wall of the recess. The height of the chamfered surface is not lower than the height of the substrate carried in the recess, and the height of the chamfered surface relative to the top surface of the substrate does not exceed 5% of the depth of the arc groove.

15. The vapor phase growth apparatus according to claim 14, characterized in that: The chamfered surface is covered with a thermally conductive coating, and the thermal conductivity of the thermally conductive coating is lower than the thermal conductivity of the non-load-bearing surface.

16. The vapor growth apparatus according to claim 1, characterized in that: The top surface of the substrate holding device includes a non-load-bearing surface surrounding the cavity, and the inner wall of the arc-shaped groove connected to the non-load-bearing surface is covered with a thermal conductive coating, and the thermal conductivity of the thermal conductive coating is lower than the thermal conductivity of the non-load-bearing surface.

17. The vapor growth apparatus according to claim 1, characterized in that: The number of the recess groups is at least N, and they are arranged sequentially from the inside to the outside around the center of the substrate holding device, N is a positive integer greater than or equal to 2, and in adjacent recess groups: The number of the recesses in the inner circle recess group close to the rotation center O of the substrate holding device is less than the number of the recesses in the outer circle recess group far from the rotation center O of the substrate holding device; The inner circle recess group includes a first recess, the outer circle recess group includes a second recess and a third recess that are adjacent to each other and adjacent to the first recess, and an extension line of a line between a rotation center O of the substrate holding device and a center of the first recess passes between the second recess and the third recess.

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