A vapor growth apparatus

Abstract

The present invention provides a vapor growth apparatus, which includes a reaction chamber, a substrate holding device, a gas injection device, and a rotation driving device. The substrate holding and carrying device is provided with a plurality of cavities for carrying substrates, and arc-shaped grooves are formed at the edges of the cavities. When the substrate is placed on the carrying surface of the cavity, a part of the edge of the substrate is suspended above the arc-shaped groove. During the rotation of the substrate holding device driven by the rotation driving device, the area where the edge carrying surface of each cavity faces away from the incoming flow direction of the rotational airflow formed by the process gas on the top surface of the substrate holding device. The present invention forms an arc-shaped groove on the windward surface of the cavity, and 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 cavity on the overheating of the edge of the substrate, and at the same time use the heat transfer of the side wall of the cavity on the leeward surface to compensate the temperature of the substrate, thereby improving the temperature uniformity of the substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices and apparatuses, and particularly to a vapor growth apparatus. Background Art

[0002] The reaction chamber is a crucial chamber in the semiconductor device manufacturing process. The reaction chamber of the vapor growth apparatus brings reactants by gas and establishes a flow field. For example, for a reaction chamber for growing materials through a gas-phase reaction, during the process of process growth, the transportation of the gas source materials and the removal of by-products after the growth reaction are completed through the reaction chamber flow field jointly established by the carrier gas and the reactant gas.

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

[0004] For semiconductor films with high requirements for film quality, such as InGaAsP epitaxial wafers, they have a strong dependence on temperature, and precise temperature control is required to ensure the quality of epitaxial film formation. In addition, the differences in gas flow and temperature at different positions on the substrate surface will cause the obtained semiconductor wafers to have characteristic differences and produce defective products. Summary of the Invention

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

[0006] To achieve the above object, the present invention provides a vapor growth apparatus, including:

[0007] A reaction chamber;

[0008] A substrate holding device, disposed in the reaction chamber. The top surface of the substrate holding device is provided with a plurality of concave cavities along the same circumferential direction to form a concave cavity group, and arc-shaped grooves are provided at the edges of each concave cavity;

[0009] A gas injection device, disposed in the reaction chamber and oppositely arranged with the top surface of the substrate holding device to provide process gas;

[0010] A rotation driving device, hermetically and movably disposed in the reaction chamber and fixedly connected to the substrate holding device to drive the substrate holding device to rotate around the central axis of the top surface of the substrate holding device;

[0011] Wherein, the recess includes an inner bearing surface and an edge bearing surface with flush and joined top surfaces. The arc-shaped groove surrounds the inner bearing surface. The edge bearing surface is located between two ends of the arc-shaped groove, so that the placed substrate is supported by the inner bearing surface and the edge bearing surface, and a partial edge of the substrate is suspended above the arc-shaped groove. During the rotation of the substrate holding device driven by the rotation driving device, process gas forms a rotating air flow on the top surface of the substrate holding device. The region where the edge bearing surface of each recess faces away from the oncoming flow direction of the rotating air flow, and the flowing direction of the rotating air flow is opposite to the rotation direction of the substrate holding device.

[0012] Optionally, the number of the recess groups is at least 2, and they are arranged in sequence from inside to outside around the rotation center O of the substrate holding device. The number of recesses in each recess group is at least 3. Among adjacent recess groups, the number of recesses in the inner ring recess group closer to the middle of the substrate holding device is less than the number of recesses in the outer ring recess group farther from the middle of the substrate holding device.

[0013] Optionally, the top surface opening of the arc-shaped groove includes opposite first and second ends. The first acute angle a formed by the first connection line between the first end and the center O' of the recess where the arc-shaped groove is located and the second connection line between the second end and the center O' of the recess where the arc-shaped groove is located is 85° to 95°.

[0014] Optionally, the second end is closer to the rotation center O of the substrate holding device than the first end. The angle β formed by the third connection line between the rotation center O of the substrate holding device and the center O' of the recess where the arc-shaped groove is located and the second connection line is 40° to 70°.

[0015] Optionally, the number of the recess groups is at least 2 and they are arranged in sequence from inside to outside around the rotation center O of the substrate holding device. The angle β of each recess in the same recess group is the same, and the first acute angle a is the same.

[0016] Optionally, among adjacent recess groups, the angle β of each recess in the inner ring recess group closer to the rotation center O of the substrate holding device is less than the angle β of each recess in the outer ring recess group farther 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 included angle β of each recess is 40° to 50°.

[0017] Optionally, the number of the recess groups is at least N, and they are arranged in sequence from inside to outside around the center of the substrate holding device. N is a positive integer greater than or equal to 2. The number of recesses in the same recess group is at least 3.

[0018] When N is less than or equal to 3, among the adjacent recess groups, the duty ratio of the inner ring recess group closer to the center of the substrate holding device is less than that of the outer ring recess group farther from the center of the substrate holding device;

[0019] When N is greater than 3, among the (N - 1)-th recess group to the N-th recess group from the inside to the outside, the duty ratios of the adjacent recess groups are the same.

[0020] Optionally, the duty ratio of the recess group closest to the center of the substrate holding device is 50% - 55%, and the duty ratio of the recess group farthest from the center of the substrate holding device does not exceed 75%.

[0021] Optionally, in the same recess group, the recesses are evenly arranged around the rotation axis of the substrate holding device, each recess has the same structure, and the arc grooves of each recess have the same structure.

[0022] Optionally, the radial width of the top opening of the arc groove does not exceed 10% of the radial length of the area surrounded by the bottom edge of the recess.

[0023] Optionally, the opening of the arc groove is in a fan-shaped ring shape, and the center of the fan-shaped ring coincides with the center of the recess where it is located.

[0024] Optionally, the side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc groove is inclined to the top surface of the internal bearing surface, so that the outer diameter of the top of the structure surrounded by the internal bearing surface and the side wall is smaller than the outer diameter of the bottom.

[0025] Optionally, the side wall formed between the top surface of the internal bearing surface and the bottom surface of the arc groove is a stepped side wall or a convex arc side wall.

[0026] Optionally, the top surface of the substrate holding device includes a non-bearing surface surrounding the recess, the non-bearing surface and the side wall of the recess are a chamfered surface, 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.

[0027] Optionally, the chamfered surface is covered with a heat-conducting coating, and the thermal conductivity of the heat-conducting coating is lower than that of the non-bearing surface.

[0028] 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 heat-conducting coating, and the thermal conductivity of the heat-conducting coating is lower than that of the non-bearing surface.

[0029] Optionally, the number of the groups of recesses is at least N, and the groups of recesses are arranged in sequence from the inside to the outside around the center of the substrate holding device, where N is a positive integer greater than or equal to 2. Among adjacent groups of recesses:

[0030] The number of recesses in the inner ring group of recesses closer to the rotation center O of the substrate holding device is less than the number of recesses in the outer ring group of recesses farther from the rotation center O of the substrate holding device;

[0031] The inner ring group of recesses includes a first recess, and the outer ring group of recesses includes a second recess and a third recess that are adjacent to each other and adjacent to the first recess. The extension line of the connection line between the rotation center O of the substrate holding device and the center of the first recess passes between the second recess and the third recess.

[0032] As described above, the vapor growth device of the present invention has the following beneficial effects:

[0033] In the substrate holding device of the vapor growth device of the present invention, a plurality of recesses for carrying the substrate are provided, and an arc-shaped groove is provided at the edge of the recess. When the substrate is placed on the bearing surface of the recess, a part of the edge of the substrate is suspended above the arc-shaped groove. During the rotation of the substrate holding device driven by the rotation driving device, the area where the bearing surface of the edge of each recess faces away from the oncoming flow direction of the rotational gas flow formed on the top surface of the substrate holding device by the process gas. Since the temperature of the gas flow increases when flowing through the substrate holding surface, the temperature of the gas flow gradually decreases during the process of flowing through the substrate with a relatively lower temperature, and an arc-shaped groove is formed on the windward surface of the recess. The inner bearing surface and the edge bearing surface jointly carry the substrate, which can reduce the adverse effect of the side wall of the recess on the overheating of the edge of the substrate, and at the same time use the heat transfer of the side wall of the recess on the leeward surface to compensate the temperature of the substrate, thereby improving the temperature uniformity of the substrate.

[0034] This temperature uniformity includes not only different regions at the edge and inside of the same substrate, but also different substrates in different substrate loading areas on the substrate holding device. Therefore, the substrate holding and loading 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 ring substrates and outer ring substrates carried by the substrate loading area. Description of the Drawings

[0035] Figure 1 It shows a front sectional view schematic diagram of the vapor growth equipment provided by the present invention.

[0036] Figure 2 It shows Figure 1 A top view structural schematic diagram of the substrate holding device in

[0037] Figure 3 It shows Figure 2 A top view structural schematic diagram of the recess in

[0038] Figure 4 Shown as Figure 2 The top - view structural schematic diagram of the first set of cavities in

[0039] Figure 5 Shown as Figure 3 The sectional - view structural schematic diagram in the A - A direction in

[0040] Figure 6 Shown as in an alternative embodiment Figure 5 The partial enlarged structural schematic diagram of part B in

[0041] Figure 7 Shown as in another alternative embodiment Figure 5 The partial enlarged structural schematic diagram of part B in

[0042] Figure 8 Shown as the local enlarged structural schematic diagram of the cavity corresponding part B in the vapor - phase growth equipment provided by another alternative embodiment Figure 5 in

[0043] Figure 9 Shown as the surface fluorescence excitation spectrum of the substrate measured under predetermined process conditions when the top of the cavity is flat and not grooved.

[0044] Figure 10 Shown as the surface fluorescence excitation spectrum of the substrate measured under the same process conditions when an arc - shaped groove is provided at the edge of the cavity Figure 9 as

[0045] Figure 11 Shown as the surface fluorescence excitation spectrum of the substrate measured under the same process conditions when an annular groove is provided at the edge of the cavity Figure 9 as

[0046] Element marking description

[0047] 1. Substrate holding device; 11. Top surface; 12. Bottom surface; 100. Cavity; 100 - 1. First cavity; 100 - 2. Second cavity; 100 - 3. Third cavity; 101. First set of cavities; 102. Second set of cavities; 111. Inner bearing surface; 112. Edge bearing surface; 113. Arc - shaped groove; 1131. First end; 1132. Second end; 114. Side wall; 114′. Stepped side wall; 114′′. Outward - convex arc - shaped side wall; 115. Chamfered surface; 116. Heat - conducting coating; 200. Substrate; 2. Heating device; 3. Rotation driving device; 4. Gas injection mechanism; 5. Reaction chamber. Detailed implementation manners

[0048] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0049] This embodiment provides a vapor growth device, which can be, for example, a vapor deposition device. Specifically, it can be a Chemical Vapor Deposition (CVD) device or a Physical Vapor Deposition (PVD) device. The vapor deposition device 10 therein can be a Plasma-Enhanced Chemical Vapor Deposition (PECVD) device, a Metal-organic Chemical Vapor Deposition (MOCVD) device, etc. This embodiment takes the MOCVD device as an example for illustration. It should be understood that this device is merely exemplary, and the present invention is not limited to this type of device.

[0050] As Figure 1 shown, the vapor growth device of the present invention has a reaction chamber 5, and a substrate holding device 1 for holding a substrate 200 is arranged in the reaction chamber 5. The reaction chamber 5 is also provided with a gas injection device for supplying process gas into the reaction chamber 5. The gas injection device is disposed opposite to the substrate holding device 1. Specifically, the gas outlet side of the gas injection device is disposed opposite to the top surface 11 of the substrate holding device 1 for holding the substrate 200. A heating device 2 is further arranged on the bottom surface 12 of the substrate holding device 1, which can heat the substrate holding device 1 and transfer heat through the substrate holding device 1 to heat the held substrate 200. As Figure 1 shown, the vapor growth device of the present invention further 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 gas phase reaction.

[0051] The cross-section of the reaction chamber 5 of the vapor growth device is generally a circular or quasi-circular structure, or can be a rectangular structure and other structures well-known to those skilled in the art, which will not be elaborated here. The reaction chamber 5 is a vertical flow chamber with vertical gas inlet. The reaction chamber 5 can be a positive chamber in which the gas injection mechanism 4 is disposed opposite to the substrate holding device 1, and the gas injection mechanism 4 is located in the upper part and the substrate holding device 1 is located in the lower part. This embodiment takes Figure 1Taking the reaction chamber 5 with a circular cross-section as an example, where the gas injection mechanism 4 is located in the upper part and the substrate holding device 1 is located in the lower part, the gas injection mechanism 4 will be described.

[0052] Referring to Figure 1 and Figure 2 In the reaction chamber 5, a gas injection mechanism 4 for carrying the substrate 200 to be processed is provided, which is disposed opposite to the substrate holding device 1. For example, it is arranged at the top of the reaction chamber 5 to inject 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 generally presents a disc-shaped structure, and the gas outlet surface of the gas injection mechanism 4 faces the substrate holding device 1.

[0053] Similarly referring to Figure 1 shown, a main axis T1 is defined. This main axis T1 is perpendicular to the gas outlet surface of the disc-shaped gas injection mechanism 4 and passes through the geometric center of the gas outlet surface of the gas injection mechanism 4. The main axis T1 and the rotation axis T2 of the substrate holding device 1 can be parallel or non-parallel. Preferably, the main axis T1 is parallel to the rotation axis T2 of the substrate holding device 1 (i.e., the central axis of the top surface of the substrate holding device 1), and preferably, the main axis T1 coincides with the rotation axis T2.

[0054] A number of cavities 100 are distributed on the top surface 11 of the substrate holding device 1, and these cavities 100 are recessed from the top surface 11 of the substrate holding device 1 towards the bottom surface 12. The size, quantity, and distribution of the cavities 100 on the substrate holding device 1 can be designed according to the size, thickness, quantity of the substrate 200 to be carried and held, as well as the size of the substrate holding device 1, etc. For the generally disc-shaped substrate 200, the cavities 100 are correspondingly designed to have a circular opening structure, and the opening size is set corresponding to the size of the substrate 200.

[0055] In an alternative embodiment, a number of cavities 100 are formed along the same circumferential direction on the top surface 11 of the substrate holding device 1, and these cavities 100 on this circumferential direction form a cavity group. On the top surface 11 of the same substrate holding device 1, N cavity groups are formed along different circumferential directions from the inside to the outside around the rotation center of the substrate holding device 1, such as 2, 3, or more cavity groups. Each cavity group includes a number of cavities 100. Further, each cavity group contains at least 3 cavities 100. The geometric centers of the number of cavities 100 in the same cavity group are located on the same circumference of the top surface 11 of the substrate holding device 1.

[0056] In an alternative embodiment, among adjacent cavity groups, the number of cavities 100 in the inner ring cavity group closer to the middle of the substrate holding device 1 is less than the number of cavities 100 in the outer ring cavity group farther from the middle of the substrate holding device 1.

[0057] In an alternative embodiment, in the same recess group, a plurality of recesses 100 are uniformly arranged along the rotation axis T2 of the substrate holding device 1, that is, the spacing distance between adjacent recesses 100 is the same.

[0058] Embodiment 1

[0059] In the vapor growth apparatus of the present embodiment, an example is described in which two recess groups are formed on the top surface 11 of the substrate holding device 1. Figure 2 The top view structural schematic diagram of the substrate holding device 1 of the present embodiment is shown. It should be understood that in the present invention, the so-called "looking up" is the view direction of observing from the bottom surface 12 of the substrate holding device 1 towards the top surface 11, and "looking down" is the view direction of observing from the top surface 11 of the substrate holding device 1 towards the bottom surface 12.

[0060] As Figure 2 shown, in the present embodiment, on the top surface 11 of the substrate holding device 1, a first recess group 101 and a second recess group 102 are formed along two different circumferences, the first circumference C1 and the second circumference C2. 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. There are 3 recesses 100 distributed in the first recess group 101, and 9 recesses 100 distributed in the second recess group 102.

[0061] In an alternative embodiment, as Figure 2 shown, in the first recess group 101 close to the rotation center O of the substrate holding device 1, there is a first recess 100-1. In the second recess group 102 far from the rotation center O of the substrate holding device 1, there are a second recess 100-2 and a third recess 100-3. 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 connection line between the rotation center O of the substrate holding device 1 and the center O' of the first recess 100-1 passes through between the second recess 100-2 and the third recess 100-3. This enables the recesses 100 in the inner ring recess group and the outer ring recess group to be staggered, which can optimize the distribution of the recesses 100 on the substrate holding device 1 and achieve the optimization of the bearing area of the top surface 11 of the substrate holding device 1.

[0062] In the present embodiment, the recess group and the duty ratio are defined. As Figure 2 shown, taking the second recess group 102 (i.e., the outer ring recess group) as an example, the distribution of the multiple recesses 100 of the recess group pair is between two internally tangent circumferences, that is, Figure 2Between the third circumference C3 and the fourth circumference C4 shown, the area of the annular region sandwiched by 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 the respective recesses 100 to the area S of the annular region is the duty ratio of the second recess group 102. In an alternative 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, in adjacent recess groups, the duty ratio of the inner ring recess group closer to the center O of the substrate holding device 1 is less than the duty ratio of the outer ring recess group farther from the center O of the substrate holding device 1; when N is greater than 3, among the third to the Nth recess groups from the inside out, the duty ratios of adjacent recess groups are the same. In a further alternative embodiment, the duty ratio of the recess group closest to the center of the substrate holding device 1 is 50% to 55%, and the duty ratio 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 millimeters. The opening diameter of each recess 100 can be slightly larger than 2 inches or slightly larger than 3 inches, or both sizes of recesses 100 can be provided on the same substrate holding device 1 at the same time. Taking the arrangement of two recess groups as an example, the inner ring recess group is provided with 3 recesses 100, and the outer ring recess group is provided with 9 recesses 100.

[0063] To ensure the heat transfer efficiency 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 about the central axis of its top surface, and the process gas injected above the substrate 200 will be dragged by the rotation of the substrate holding device 1 to form a rotating gas flow. Due to the different thermal conductivities of the substrate 200 and the substrate holding device 1, affected by the convection and radiation of the gas field and temperature field in the process environment, the temperature of the substrate holding device 1 is higher than the temperature of the substrate 200. The process gas flows along the incoming flow direction through the non-bearing surface of the substrate holding device 1 that does not carry the substrate 200 and is heated, and during its subsequent flow through the nearby substrate 200, it has a certain heating effect on the substrate 200, and this heating effect weakens along the incoming flow direction, thus exacerbating the non-uniformity of the temperature of the substrate 200. By adjusting the duty ratios of the respective recess groups to increase, that is, the duty ratio of the recess group closest to the center of the substrate holding device 1 is 50% to 55%, and the duty ratio of the recess group farthest from the center of the substrate holding device 1 does not exceed 75%, the area of the non-bearing surface near the recesses 100 is compressed to minimize the adverse effect of the process gas heated by the substrate holding device 1 on the temperature uniformity of the substrate.

[0064] In the embodiment of the present invention, the flow direction of the rotating gas flow formed by the process gas is opposite to the rotation direction of the substrate holding device 1.

[0065] In some specific embodiments, for example, in 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.

[0066] After 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. The side wall of the cavity 100 will transfer heat to the substrate 200, and this heat transfer will cause the temperature of the edge of the substrate 200 to rise significantly compared to the temperature of the middle part. Especially under the action of the centrifugal force generated by the rotation of the substrate holding device 1 driven by the rotation drive device 3, especially under the action of the centrifugal force of high-speed rotation as described above, a part of the side wall of the substrate 200 will be closer to or even fit against the side wall of the cavity 100, and the above temperature influence will be more significant. Specifically, an InP substrate is placed on a cavity with a flat bottom and no grooves. 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, a film is formed on the substrate. The temperature of the film formed on the substrate is measured using a photoluminescence tester to obtain Figure 9 The surface fluorescence excitation spectrum diagram shown. In this spectrum diagram, the red region is the long-wavelength region, and the blue region is the short-wavelength region. 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 cavity with a flat bottom and no grooves, and the temperature uniformity is poor. To reduce the difference in the temperature of the edge of the substrate 200 compared to the temperature of the middle part, in this embodiment, the cavity 100 is provided with an arc-shaped groove 113 at the edge to reduce the contact area between the edge of the substrate 200 and the cavity 100, and weaken the influence of the heat transfer of the side wall of the cavity 100 on the temperature of the edge of the substrate 200. Under Figure 9 the same process conditions, the measured surface fluorescence excitation spectrum diagram is as shown in Figure 10 shown. As can be seen from Figure 10 it, when the arc-shaped groove 113 is provided at the edge of the cavity 100, the standard deviation Std Dev value of the surface temperature of the substrate in the cavity 100 decreases significantly.

[0067] As shown in Figure 2 and Figure 3 shown, in this embodiment, the cavity 100 includes an internal bearing surface 111 and a side bearing surface 112 with flush and joined top surfaces. An arc-shaped groove 113 is provided at the edge of the cavity 100 from the top surface downward. The arc-shaped groove 113 surrounds the internal bearing surface 111, and the side bearing surface 112 is located between the two ends of the arc-shaped groove 113. As shown in Figure 2 and Figure 3 shown, in this embodiment, the opening of the arc-shaped groove 113 in the cavity 100 is in a fan-shaped ring (i.e., a part of a circular ring), and the center of the fan-shaped ring coincides with the center O' of the cavity 100 where it is located. Further, as shown inFigure 3 As shown, the top opening of the arc-shaped groove 113 includes opposite first end 1131 and second end 1132. The first acute angle a formed by the first connection line L1 between the first end 1131 and the center O' of the recess 100 and the second connection line L2 between the second end 1132 and the center O' of the recess 100 is 85° to 95°. The setting of this angle ensures the proportion of the arc-shaped groove 113 and the edge bearing surface 112, and ensures the uniformity of the temperature of the substrate 200 due to the heat transfer of the recess 100.

[0068] In an alternative embodiment, as Figure 4 shown, taking the inner ring recess group as an example, the second end 1132 of the arc-shaped groove 113 is closer to the rotation center O of the substrate holding device 1 than the first end 1131. A third connection line L3 is formed by connecting the rotation center O of the substrate holding device 1 and the center O' of the recess 100 where the arc-shaped groove 113 is located. The angle β formed by the third connection line L3 and the second connection line L2 is 40° to 70°.

[0069] In a further alternative 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 in sequence from the inside to the outside around the rotation center O of the substrate holding device 1. The above-mentioned angle β of each recess 100 in the same recess group is the same, and the first acute angle a is the same.

[0070] In adjacent recess groups, the angle β of each recess 100 in the inner ring recess group closer to the rotation center O of the substrate holding device 1 is smaller than the angle β of each recess 100 in the outer ring recess group farther 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 included angle β of each recess 100 is 40° to 50°. The setting of the above-mentioned angle β limits the position of the arc-shaped groove (i.e., the edge support surface) in each recess 100 relative to the rotation center O of the substrate holding device 1, ensuring that the arc-shaped groove is 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-shaped groove 113 and the edge bearing surface 112, and ensures the uniformity of the temperature of the substrate 200 due to the heat transfer of the recess 100.

[0071] When the substrate 200 is placed in the recess 100, it is supported by the inner bearing surface 111 and the edge bearing surface 112 of the recess 100, and a partial edge of the substrate 200 at the position of the arc-shaped groove 113 is suspended above the arc-shaped groove 113. During the vapor growth process, the rotation driving device 3 drives the substrate holding device 1 to rotate, and the area where the edge bearing surface 112 of each recess 100 is located faces away from the oncoming flow direction of the process gas (i.e., the oncoming flow direction points from the position where the arc-shaped groove 113 is located to the position where the edge bearing surface 112 is located). The air flow entering the reaction chamber 5 is heated on the surface of the substrate holding device 1. Due to the different thermal conductivities of the substrate 200 and the substrate holding device 1, the temperature of the substrate 200 is relatively lower than that of the substrate holding device 1. The heating effect of the process gas oncoming flow on the substrate 200 during the process of flowing through the substrate 200 will be reduced, resulting in a relatively significant temperature difference between the area of the substrate 200 far from the arc-shaped groove 113 and the area close to the arc-shaped groove 113. As Figure 11 shown, the recess 100 is provided with an annular groove, and its width is designed to be the same as the width of the arc-shaped groove 113. Under the same Figure 9 process conditions, the measured surface fluorescence excitation spectrum is as shown in Figure 11 . It can be seen from Figure 11 that when the arc-shaped groove 113 is provided at the edge of the recess 100, the standard deviation Std Dev value of the surface temperature of the substrate in the recess 100 is higher than the Figure 10 Std Dev value, and the temperature field distribution uniformity of the substrate is lower than the Figure 10 substrate temperature uniformity shown. Therefore, as described above, no groove is provided on the leeward side of the recess 100, and the arc-shaped groove 113 is formed on the windward side of the recess 100. Correspondingly, the substrate 200 in the corresponding area of the leeward side is jointly supported by the inner bearing surface 111 and the edge bearing surface 112 of the recess 100. Therefore, the heat transfer of the side wall of the recess 100 on the leeward side can be used to compensate the temperature of the substrate 200, thereby reducing the temperature difference between the middle and the edge of the substrate 200, as well as between the windward side and the leeward side.

[0072] In an alternative embodiment, in the same recess group, the recesses 100 are uniformly arranged around the rotation axis T2 of the substrate holding device 1, each recess 100 has the same structure, and the arc-shaped grooves 113 of each recess 100 also have the same structure. In an alternative embodiment, in adjacent recesses 100 of the same recess group, the opening of the arc-shaped groove 113 of one recess 100 is located at a first position relative to the gas injection device, and the opening of the arc-shaped groove 113 of the other recess 100 is located at a second position relative to the gas injection device. Specifically, taking a disc-shaped gas injection device as an example, in Figure 1In the top-down perspective shown above, the first position and the second position are two adjacent positions on the same circumference in the projection of the gas injection device. Moreover, the first position and the second position cover two adjacent cavities 100 in the same cavity group on the top surface 11 of the substrate holding device 1. During the rotation of the substrate holding device 1 driven by the rotation driving device 3, the arc-shaped groove 113 of a cavity 100 is transferred from the first position to the second position relative to the gas injection device. Referring again to Figure 2 , for example, the arc-shaped groove 113 of the second cavity 100-2 in the second cavity group 102 is located at the first position, and the arc-shaped groove 113 of the third cavity 100-3 is located at the second position. When the rotation driving device 3 drives the substrate holding device 1 to rotate, at a certain moment, the arc-shaped groove 113 of the second cavity 100-2 is transferred to the second position.

[0073] In an alternative embodiment, the radial width of the top surface opening of the arc-shaped groove 113 (i.e., the radial distance difference between the two arc lines inside and outside the arc-shaped 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 maximum radial width of the top surface opening of its arc-shaped groove 113 is 7 mm. If the radial width of the top surface opening of the arc-shaped groove 113 is too large, the area of the bonding surface for supporting the wafer is reduced, and the part in direct contact with the substrate 200 for heat transfer is reduced, which is not conducive to temperature uniformity.

[0074] Embodiment 2

[0075] This embodiment also provides a vapor deposition apparatus. In this embodiment, as Figure 5 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-shaped groove 113 is inclined to the top surface of the internal bearing surface 111, so that the outer diameter R1 of the top of the structure surrounded by the internal bearing surface 111 and the side wall 114 is smaller than the outer diameter R1 of the bottom. Since the gas flow is heated to a higher temperature when flowing through the non-bearing surface and then flowing through the substrate, it exacerbates the temperature non-uniformity of the substrate (for the specific reason analysis, please refer to the relevant analysis in Embodiment 1). Setting the inclined side wall 114 can 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.

[0076] In an alternative embodiment, as Figure 6 shown, the side wall formed between the top surface of the internal bearing surface 111 and the bottom surface of the arc-shaped groove 113 is a stepped side wall 114'. For example, it can include two or more levels of steps. As Figure 6 shown, in this embodiment, the stepped side wall 114' includes three levels of steps, and the height of each level of step can be the same or different, and the width of each level of step in the radial direction of the cavity 100 can be the same or different.

[0077] In some alternative embodiments, the step height increases successively in the direction from the edge of the recess 100 towards the middle, and the increment trend decreases successively. The steps become flatter closer to the middle of the recess 100.

[0078] In another alternative embodiment, as Figure 7 shown, the side wall formed between the top surface of the internal bearing surface 111 and the bottom surface of the arc-shaped groove 113 is an arc-shaped side wall. Further, this arc-shaped side wall is an outwardly convex arc-shaped side wall 114'' that protrudes from the internal bearing surface 111 towards the arc-shaped groove.

[0079] Embodiment III

[0080] This embodiment also provides a vapor growth apparatus. In this embodiment, as Figure 8 shown, the top surface 11 of the substrate holding device 1 around the recesses 100 is a non-bearing surface, and a chamfered surface 115 is formed between the non-bearing surface and the side wall of the recess 100. The height of this chamfered surface 115 is not lower than the height of the substrate 200 carried in the recess 100. The chamfered surface 115 can be, for example, an arc-shaped surface or a similar inclined surface. At the same time, as Figure 8 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-shaped groove 113. In an alternative 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-shaped groove 113. In one example, for instance, the depth D of the arc-shaped groove 113 = 675 micrometers, and the height H of the chamfered surface 115 relative to the top surface of the substrate 200 = 25 micrometers.

[0081] In a further alternative embodiment, as Figure 8 shown, the chamfered surface 115 is covered with a heat-conducting coating 116, and the thermal conductivity of this heat-conducting coating 116 is lower than that of the non-bearing surface. Thus, heat transfer from the substrate holding device 1 to the edge of the substrate 200 in the recess 100 can be appropriately reduced.

[0082] In another alternative embodiment, the inner wall of the arc-shaped groove 113 connecting the non-bearing surface is also covered with a heat-conducting coating 116. Further, as Figure 8 shown, both the above-mentioned inner wall of the arc-shaped groove 113 and the chamfered surface 115 are covered with a heat-conducting coating layer, and the above-mentioned heat-conducting coating layer forms a continuous structure on the above-mentioned inner part and the chamfered surface 115. The thermal conductivity of the heat-conducting coating 116 is lower than that of the non-bearing surface, which can appropriately reduce heat transfer from the non-bearing surface of the substrate holding device 1 to the edge of the substrate 200 in the recess 100, and is beneficial to the temperature uniformity of the substrate 200.

[0083] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should 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; The recess comprises an inner bearing surface and an edge bearing surface which are flush with and connected to each other, the arc groove surrounds the inner 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 inner bearing surface and the edge bearing surface, and part of the edge of the substrate is suspended above the arc groove; when the substrate holding device is driven to rotate by the rotary drive device, 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; The top surface opening of the arc-shaped groove comprises a first end and a second end opposite to each other, and a first acute angle a formed by a first connecting line between the first end and the center O' of the cavity where the arc-shaped groove is located and a second connecting line between the second end and the center O' of the cavity where the arc-shaped groove is located is 85° to 95°; 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 connecting line between 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 connecting line is 40° to 70°; 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°.

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 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.

4. 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 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.

5. The vapor phase growth apparatus according to claim 1, characterized in that: 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%.

6. The vapor 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.

7. The vapor phase 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.

8. The vapor 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.

9. 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.

10. The vapor phase growth apparatus according to claim 9, 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.

11. The vapor phase 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.

12. The vapor phase growth apparatus according to claim 11, 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.

13. The vapor phase 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 the inner wall of the arc-shaped groove connecting 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.

14. 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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