Heat insulation ring and chemical vapor deposition equipment

Abstract

The invention provides a heat insulation ring and chemical vapor deposition equipment, the chemical vapor deposition equipment comprises a reaction cavity, a wafer tray is arranged at the bottom of the reaction cavity, a heater is arranged below the wafer tray, the heat insulation ring is arranged on the outer side of the wafer tray, the heat insulation ring is provided with an annular inclined surface, and the annular inclined surface is provided with a heat insulation layer. The annular inclined surface faces the edge of a top sealing plate in the reaction cavity; the heat insulation ring at least comprises a first arc-shaped section and a second arc-shaped section in the circumferential direction, the radiance of the first arc-shaped section is larger than that of the second arc-shaped section, and at least part of the area of the first arc-shaped section right faces a wafer conveying gate plate in the reaction cavity. The device is used for solving the problems that the edge temperature of a top sealing plate of existing chemical vapor deposition equipment is low, a low-temperature surface is formed at a wafer transfer gate plate, and a flow field above a heat insulation ring is not uniform.

Description

Technical Field

[0001] This invention relates to the field of semiconductor equipment technology, and in particular to a heat insulation ring and a chemical vapor deposition apparatus. Background Technology

[0002] In chemical vapor deposition (CVD) processes, especially in metal-organic chemical vapor deposition (MOCVD) processes for fabricating MicroLEDs (Micro Light Emitting Diodes), uniformity is a key indicator, and the main factors affecting this indicator include temperature field uniformity and flow field uniformity.

[0003] Existing chemical vapor deposition (CVD) equipment typically includes a reaction chamber, within which a top sealing plate, a flow-limiting ring, and a wafer tray form the process reaction zone. The wafer tray is driven to rotate by a tray shaft, and a heater is located beneath the wafer tray, typically employing radiant or radio frequency heating. To minimize heat loss from the edges of the wafer tray, its diameter is smaller than that of the heater, and a heat insulation ring is installed around the outside of the wafer tray to reduce heat conduction to the outside.

[0004] Existing chemical vapor deposition equipment has the following problems during the process:

[0005] 1. The top cover is mainly exposed to heat radiation from the wafer tray. The center of the top cover receives more radiation than the edges, and the temperature at the edges is much lower than that at the center. Excessive temperature difference can cause the top cover to crack and shorten its service life.

[0006] 2. The side wall of the reaction chamber has a transfer port, and a transfer gate is provided at the flow-limiting ring corresponding to the position of the transfer port. This transfer gate is an independent gate, and the heat radiation and heat conduction it receives are less than those in other areas of the flow-limiting ring. Therefore, a low-temperature surface is formed at this point, which affects the uniformity of the process.

[0007] 3. In some processes that require in-situ cleaning, the deposits at the plate transfer gate may not be cleaned due to the low temperature.

[0008] 4. Due to the height difference between the heat insulation ring and the wafer tray, the flow field above the heat insulation ring cannot transition smoothly, resulting in turbulence and affecting the uniformity of the flow field.

[0009] The above statements are for the purpose of providing background information in relation to this application only and do not necessarily constitute prior art. Summary of the Invention

[0010] The purpose of this invention is to provide a heat insulation ring and a chemical vapor deposition (CVD) apparatus to solve at least one of the aforementioned problems existing in existing CVD apparatuses.

[0011] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0012] A heat insulation ring is used in a chemical vapor deposition (CVD) apparatus, the CVD apparatus including a reaction chamber, a wafer tray at the bottom of the reaction chamber, a heater below the wafer tray, and the heat insulation ring disposed on the outside of the wafer tray.

[0013] The heat insulation ring has an annular inclined surface, which faces the edge of the top sealing plate inside the reaction chamber;

[0014] The heat insulation ring includes at least a first arc-shaped section and a second arc-shaped section along the circumferential direction. The emissivity of the first arc-shaped section is greater than that of the second arc-shaped section. At least a portion of the first arc-shaped section is directly opposite the plate transfer gate in the reaction chamber.

[0015] Optionally, the annular inclined surface is a plane or a convex continuous curved surface.

[0016] Optionally, along the circumference of the heat insulation ring, the top of the annular inclined surface is not higher than the upper surface of the wafer tray.

[0017] Optionally, during the process, the normal at the bottom of the inclined surface of the first arc-shaped section intersects with the transfer plate gate.

[0018] The normal to the bottom of the inclined surface of the second arc-shaped section intersects with the flow-limiting ring, which is located inside the reaction chamber and has an opening. The plate transfer gate is used to close the opening during the process.

[0019] Optionally, the normal at the top of the annular inclined surface intersects with the top sealing plate.

[0020] Optionally, the normal at the midpoint of the annular inclined surface along the circumference intersects with the top sealing plate.

[0021] Optionally, the material of the first arc-shaped segment is different from that of the second arc-shaped segment, and the emissivity of the material of the first arc-shaped segment is higher than that of the material of the second arc-shaped segment.

[0022] Optionally, the heater is an electromagnetic induction heating coil, and the conductivity of the material in the first arc-shaped section is higher than that of the material in the second arc-shaped section.

[0023] Optionally, the first arc-shaped section is made of graphite, and the second arc-shaped section is made of quartz.

[0024] Optionally, the color of the inclined surface of the first arc segment is darker than the color of the inclined surface of the second arc segment.

[0025] Optionally, the surface roughness of the inclined surface of the first arc-shaped section is greater than the surface roughness of the inclined surface of the second arc-shaped section.

[0026] Optionally, the heat insulation ring is a one-piece circular ring, and at least a portion of the bottom of the heat insulation ring has a groove.

[0027] Optionally, the first arc-shaped section does not have the groove, while the second arc-shaped section has the groove.

[0028] Optionally, the heat insulation ring is a circular ring composed of multiple arc-shaped segments.

[0029] Optionally, at least one arc-shaped segment has a groove at its bottom, the groove not penetrating the two end sidewalls of the arc-shaped segment.

[0030] Optionally, the first arc-shaped section does not have the groove, while the second arc-shaped section has the groove.

[0031] Optionally, the material used in the arc-shaped section located in the region of lower temperature at the edge of the wafer tray has higher conductivity than the material used in the arc-shaped section located in the region of higher temperature at the edge of the wafer tray.

[0032] A chemical vapor deposition apparatus includes: a reaction chamber; a top sealing plate located at the top of the reaction chamber; a flow-limiting ring located below the top sealing plate and having an opening thereon; a wafer transfer gate for closing the opening during the process; and a wafer tray located at the bottom of the reaction chamber, with a heater located below the wafer tray and a heat insulation ring as described in any of the above descriptions located on the outer side of the wafer tray.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] The heat insulation ring provided by the present invention has an annular inclined surface facing the edge of the top sealing plate. As a result, the heat insulation ring can radiate more heat to the edge of the top sealing plate, increase the temperature of the edge of the top sealing plate, and thus extend the life of the top sealing plate.

[0035] The heat insulation ring can also radiate heat to the current limiting ring below the top sealing plate. Compared with other areas of the current limiting ring, the first arc-shaped section directly opposite the transfer gate has a high emissivity. Therefore, the transfer gate can radiate more heat, thereby increasing the temperature of the transfer gate and solving the problem that the transfer gate cannot be thoroughly cleaned during in-situ cleaning.

[0036] The highest point of the heat insulation ring is the top of the annular inclined surface, which ensures that the top of the annular inclined surface is not higher than the upper surface of the wafer tray, thus not obstructing the gas flow. Furthermore, the annular inclined surface slopes downwards to the suction ring, which can guide the gas, thereby making the flow field above the heat insulation ring transition smoothly and improving the uniformity of the flow field. Attached Figure Description

[0037] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0038] Figure 1 This is a structural diagram of a chemical vapor deposition (CVD) device in the prior art;

[0039] Figure 2 This is a structural diagram of a chemical vapor deposition apparatus according to an embodiment of the present invention;

[0040] Figure 3 for Figure 2 A partial view of the right half of the middle section;

[0041] Figure 4 This is a schematic diagram of another structure of the heat insulation ring;

[0042] Figure 5 This is a schematic diagram of a segmented heat insulation ring;

[0043] Figure 6 , Figure 7 These are schematic diagrams of the arc-shaped sections with and without bottom grooves, respectively.

[0044] In the figure, 10-reaction chamber; 20-wafer tray; 30-top sealing plate; 40-current limiting ring; 50-wafer transfer gate; 60-heater; 70', 70-heat insulation ring; 80-vacuum ring; 90-gas inlet device; 11-wafer transfer port; 21-rotating shaft; 71-annular inclined surface; 72a-first arc-shaped section; 72b-second arc-shaped section; 72-arc section; 73-groove. Detailed Implementation

[0045] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the solution proposed by the present invention. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of the present invention. Please refer to the drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0046] like Figure 1 As shown, a conventional chemical vapor deposition (CVD) apparatus includes a reaction chamber 10, within which a wafer tray 20, a top sealing plate 30 opposite to the wafer tray 20, and a flow-limiting ring 40 surrounding the wafer tray 20 are disposed. Within the reaction chamber 10, the wafer tray 20, top sealing plate 30, and flow-limiting ring 40 define a reaction area. At a wafer transfer port 11 on the sidewall of the reaction chamber 10, the flow-limiting ring 40 has an opening to facilitate wafer transfer. A wafer transfer gate 50 is also provided between the sidewall of the reaction chamber 10 and the flow-limiting ring 40 to close the opening during the process. A heater 60 is located below the wafer tray 20 to heat it. The heated wafer tray 20 radiates heat outward, thereby heating the top sealing plate 30 and the flow-limiting ring 40. However, the distance between the edge region of the top cover plate 30 and the wafer tray 20 is greater than the distance between the center region of the top cover plate 30 and the wafer tray 20. This results in the temperature of the edge region of the top cover plate 30 being lower than the temperature of the center region. Excessive temperature difference during the process can cause the top cover plate 30 to crack. Furthermore, the wafer transfer gate 50 is relatively far from the wafer tray 20 compared to other areas of the current-limiting ring 40, and some areas are blocked by the current-limiting ring 40. This leads to a low-temperature surface at the wafer transfer gate 50. During the in-situ cleaning process, the excessively low temperature at the wafer transfer gate 50 prevents the deposits from fully reacting with the cleaning gas, leaving residues on the wafer transfer gate 50 and forming contaminants in subsequent film deposition processes.

[0047] A heat insulation ring 70' is also provided on the radial outer side of the wafer tray 20 to reduce heat conduction from the wafer tray 20 to the outside. However, there is a height difference between the existing heat insulation ring 70' and the wafer tray 20, and the flow field above the heat insulation ring 70' cannot transition smoothly, resulting in turbulence and affecting the uniformity of the flow field.

[0048] To address the aforementioned problems, this invention provides a heat insulation ring and a chemical vapor deposition (CVD) apparatus. For example... Figure 2 and Figure 3 As shown, the chemical vapor deposition apparatus provided in this embodiment includes: a reaction chamber 10, with a top sealing plate 30 at the top and a wafer tray 20 at the bottom. A flow-limiting ring 40 surrounds the wafer tray 20 below the top sealing plate 30. The wafer tray 20, top sealing plate 30, and flow-limiting ring 40 constitute a reaction region. The top sealing plate 30 and flow-limiting ring 40 can be made of graphite. The top sealing plate 30 can be mounted on the top cover 12 of the reaction chamber 10, for example, using bolts or any other connection method that allows for the fixed mounting of the top sealing plate 30 to the top cover 12. When the apparatus is opened, the top sealing plate 30 moves as the top cover 12 is opened and closed.

[0049] The current-limiting ring 40 has an opening opposite to the wafer transfer port 11 on the side wall of the reaction chamber 10, facilitating the transfer of wafers into the reaction chamber 10. The reaction chamber 10 is also equipped with a wafer transfer gate 50, which is used to close the opening during the process. The wafer transfer gate 50 can be controlled to move by a lifting mechanism.

[0050] The wafer tray 20 is used to hold one or more wafers; preferably, the wafer tray 20 has multiple smaller trays distributed on it for holding wafers, and the smaller trays can rotate under the drive of airflow. The wafer tray 20 is supported by a pivot 21, which can drive the wafer tray 20 to rotate.

[0051] A heater 60 is provided below the wafer tray 20. In this embodiment, the heater 60 is an electromagnetic induction heating coil. In order to compensate for the heat loss in the edge area of ​​the wafer tray 20, the diameter of the heater 60 is set to be larger than the diameter of the wafer tray 20.

[0052] A heat insulation ring 70, as described in this embodiment, is also provided on the outer side of the wafer tray 20. The lower surface of the radially outer side of the heat insulation ring 70 contacts the upper surface of the radially inner side of the extraction ring 80 to support the heat insulation ring 70. There is a gap between the radially inner side of the heat insulation ring 70 and the wafer tray 20, so it does not affect the rotation of the wafer tray 20. A base plate (not shown) is provided below the wafer tray 20, which can prevent process gases from entering the non-reactive area below the wafer tray 20 through the gap between the heat insulation ring 70 and the wafer tray 20, preventing process gases from forming deposits on the lower surface of the wafer tray 20, the heater 60, the shaft 21, and other components in the non-reactive area; at the same time, it can prevent cleaning gases from corroding the heater 60. The heat insulation ring 70 is usually made of a material with low thermal conductivity, such as quartz or ceramic, which can play a heat preservation role and reduce the heat conduction from the wafer tray 20 to the outside of the reaction area.

[0053] In this embodiment, the heat insulation ring 70 has an annular inclined surface 71, and the annular inclined surface 71 faces the edge of the top sealing plate 30. As a result, the heat insulation ring 70 can radiate more heat to the edge of the top sealing plate 30, increase the temperature of the edge of the top sealing plate 30, reduce the temperature difference between the edge area and the center area of ​​the top sealing plate 30, and thus extend the life of the top sealing plate 30.

[0054] The flow-limiting ring 40 is located below the edge of the top sealing plate 30, so the heat insulation ring 70 can also radiate heat to the flow-limiting ring 40 to increase its temperature. Furthermore, the heat insulation ring 70 includes at least a first arc-shaped section 72a and a second arc-shaped section 72b circumferentially. At least a portion of the first arc-shaped section 72a faces the transfer gate 50 within the reaction chamber 10, and its emissivity is greater than that of the second arc-shaped section 72b. Therefore, compared to other areas of the flow-limiting ring 40, the transfer gate 50 can receive more heat, thereby increasing its temperature and solving the problem of incomplete cleaning of the transfer gate 50 during in-situ cleaning. In this invention, the fact that at least a portion of the first arc-shaped section 72a faces the transfer gate 50 in the reaction chamber 10 means that, in a horizontal projection, the reverse extension of the line connecting any point on the region of the first arc-shaped section 72a that faces the transfer gate 50 to the center point of the heat insulation ring 70 intersects the transfer gate 50.

[0055] Figure 2 and Figure 3 In the illustrated embodiment, the annular inclined surface 71 is a plane. In other embodiments, such as... Figure 4 As shown, the annular inclined surface 71 can also be a convex continuous curved surface, as long as it can radiate heat to the edge of the top sealing plate 30 and the flow limiting ring 40.

[0056] To meet the heating requirements of the current-limiting ring 40 and the plate transfer gate 50, during the process, the normal line at the bottom of the inclined surface of the first arc-shaped section 72a intersects with the plate transfer gate 50, and the normal line at the bottom of the inclined surface of the second arc-shaped section 72b (i.e., Figure 3 The dashed line at point A intersects with the flow-limiting ring 40, which allows more heat from the heat insulation ring 70 to radiate onto the transfer gate 50 and the flow-limiting ring 40, heating the transfer gate 50 and the flow-limiting ring 40 and increasing their temperature. Furthermore, heating the flow-limiting ring 40 can also improve the heat transfer from the flow-limiting ring 40 to the edge area of ​​the top sealing plate 30, thereby further increasing the temperature of the edge of the top sealing plate 30.

[0057] The normal to the top of the entire annular inclined surface 71 (i.e. Figure 3The dashed line at point C intersects with the top sealing plate 30, thereby ensuring that the heat insulation ring 70 can radiate heat to the edge area of ​​the top sealing plate 30, increasing the temperature of the edge of the top sealing plate 30. Furthermore, the normal line at the middle position of the annular inclined surface 71 along the circumference (i.e., Figure 3 The dashed line at point B (B being the midpoint between points A and C) intersects with the top sealing plate 30. This ensures that at least half of the annular inclined surface 71 of the heat insulation ring 70 can radiate heat to the top sealing plate 30, making the radiation from the heat insulation ring 70 to the edge region of the top sealing plate 30 greater than the radiation to the flow-limiting ring 40, thereby improving the heating effect on the edge region of the top sealing plate 30. It is understood that the heat transfer efficiency between the edge region of the top sealing plate 30 and the adjacent central region is greater than the heat transfer efficiency between the edge region of the top sealing plate 30 and the flow-limiting ring 40. Therefore, radiating most of the heat radiated by the heat insulation ring 70 to the top sealing plate 30 better solves the problem of low temperature in its edge region.

[0058] In order to achieve a higher emissivity of the first arc-shaped segment 72a than that of the second arc-shaped segment 72b, in one implementation, the material of the first arc-shaped segment 72a can be different from that of the second arc-shaped segment 72b, and the emissivity of the material of the first arc-shaped segment 72a is higher than that of the material of the second arc-shaped segment 72b.

[0059] The heater 60 is an electromagnetic induction heating coil. In another embodiment, the conductivity of the first arc-shaped section 72a is higher than that of the second arc-shaped section 72b. For example, the first arc-shaped section 72a is made of graphite, and the second arc-shaped section 72b is made of quartz. It is understood that graphite is a conductor and can be heated by magnetic field lines, while quartz cannot. Therefore, the temperature of the first arc-shaped section 72a is higher than that of the second arc-shaped section 72b, effectively heating the slide gate 50.

[0060] In another implementation, the color of the inclined surface of the first arc-shaped section 72a can be darker than the color of the inclined surface of the second arc-shaped section 72b, or the surface roughness of the inclined surface of the first arc-shaped section 72a can be greater than the surface roughness of the inclined surface of the second arc-shaped section 72b, thereby achieving that the radiant heat of the first arc-shaped section 72a is greater than that of the second arc-shaped section 72b.

[0061] In this embodiment, the heat insulation ring 70 can be a one-piece circular ring. At least a portion of the bottom of the heat insulation ring 70 has a groove, for example, the groove can be formed on the bottom surface or inner side of the heat insulation ring 70, or at the intersection of the bottom surface and the inner side. Since this embodiment uses electromagnetic induction heating, when the heat insulation ring 70 has a groove, the magnetic field lines in the heat insulation ring 70 are discontinuous, which can reduce the temperature of the heat insulation ring 70 and prevent the temperature of the heat insulation ring 70 from becoming too high, thus affecting the lifespan of the components connected to it.

[0062] Furthermore, in order not to affect the radiation effect of the heat insulation ring 70 on the transmission plate gate 50, the groove can be left unopened in the first arc-shaped section 72a, and the groove can be opened only in the second arc-shaped section 72b.

[0063] Figure 5 Another structure of the heat insulation ring is shown. This heat insulation ring 70 is a circular ring composed of multiple arc-shaped segments 72. One or more of the arc-shaped segments 72 that are opposite to the plate-transfer gate 50 are the first arc-shaped segments 72a, and one or more other arc-shaped segments 72 that are not opposite to the plate-transfer gate are the second arc-shaped segments 72b. (Combined with...) Figure 6 As shown, each arc-shaped segment 72 has overlapping structures at both ends that can cooperate with each other, allowing adjacent arc-shaped segments 72 to be spliced ​​and fixed together to form a heat insulation ring 70. Setting the heat insulation ring 70 in a multi-segment splicing form allows the magnetic field lines within the heat insulation ring 70 to be discontinuous, thereby reducing the temperature of the heat insulation ring 70 and preventing overheating, which could affect the lifespan of the components connected to it. Furthermore, as... Figure 7 As shown, at least one arc-shaped section 72 has a groove 73 at its bottom. Preferably, the groove is provided in the second arc-shaped section 72b, while the first arc-shaped section 72a does not have a groove. Preferably, the groove 73 does not penetrate through the two end sidewalls of the arc-shaped section 72. Thus, by maintaining a distance between the groove 73 and the two end sidewalls of the arc-shaped section 72, process gas can be prevented from entering the inner side of the heat insulation ring 70 through the gap between the two arc-shaped sections 72 and forming deposits.

[0064] Furthermore, it is understandable that induction heating coils cannot provide localized temperature control for a specific area. However, due to errors in coil manufacturing and variations in material resistance distribution, the magnetic field lines of the heating coil are not uniformly distributed, resulting in uneven temperature distribution when heating the wafer tray 20 and other components. This unevenness cannot be resolved by adjusting the power. In one embodiment, the multi-segment heat insulation ring 70 is designed to use materials that are easily heated by induction (high conductivity) and materials that are not easily heated by induction (low conductivity). For example, materials that are easily heated by induction (such as graphite) can be used in areas with lower temperatures at the edge of the wafer tray 20, while materials that are not easily heated by induction (such as quartz) can be used in areas with higher temperatures at the edge of the wafer tray 20. This achieves the effect of regulating the heating uniformity of the coil and improving the temperature uniformity of the wafer tray 20.

[0065] like Figure 1 , 2As shown, an inlet device 90 is located at the top center of the reaction chamber 10 to supply process gas to the reaction area. The process gas supplied by the inlet device 90 is deposited into a film on the wafer, and residual gas and reaction byproducts are discharged from the reaction chamber 10 through the extraction ring 80. The general flow direction of the gas is as follows. Figure 1 , 2 As indicated by the dashed arrow. In the prior art, due to the height difference between the heat insulation ring 70' and the wafer tray 20 (e.g., ... Figure 1 As shown in the diagram, the flow field above the insulation ring 70' cannot transition smoothly, exhibiting turbulence and affecting flow field uniformity. In this embodiment, as... Figure 2 As shown, in the circumferential direction, the highest position of the heat insulation ring 70 is the top of the annular inclined surface 71, which ensures that the top of the annular inclined surface 71 is not higher than the upper surface of the wafer tray 20. Thus, the heat insulation ring 70 will not obstruct the gas flow. Furthermore, the annular inclined surface 71 is inclined downward to the suction ring 80, which can guide the gas discharge, thereby making the flow field above the heat insulation ring 70 transition smoothly and improving the flow field uniformity.

[0066] In summary, the heat insulation ring and chemical vapor deposition equipment provided by this invention, by designing the heat insulation ring with an annular inclined surface facing the edge of the top sealing plate and the current-limiting ring, can radiate more heat to the edge of the top sealing plate through the annular inclined surface, thereby increasing the temperature of the top sealing plate edge, optimizing the overall temperature uniformity of the top sealing plate, and extending the life of the top sealing plate. Simultaneously, the first arc-shaped section directly opposite the wafer transfer gate has a higher emissivity, radiating more heat than other areas of the current-limiting ring, increasing the temperature of the wafer transfer gate and preventing it from becoming a localized low-temperature surface, thus optimizing the temperature uniformity of the entire system. Furthermore, the annular inclined surface of the heat insulation ring slopes outward and downward, eliminating the flow field dead zone between the heat insulation ring and the wafer tray, and optimizing the flow field uniformity.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0068] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A heat insulation ring, applied in a chemical vapor deposition (CVD) apparatus, the CVD apparatus comprising a reaction chamber, a wafer tray at the bottom of the reaction chamber, a heater below the wafer tray, and the heat insulation ring disposed on the outer side of the wafer tray, characterized in that, The heat insulation ring has an annular inclined surface, which faces the edge of the top sealing plate inside the reaction chamber; The heat insulation ring includes at least a first arc-shaped section and a second arc-shaped section along the circumferential direction. The emissivity of the first arc-shaped section is greater than that of the second arc-shaped section. At least a portion of the first arc-shaped section is directly opposite the plate transfer gate in the reaction chamber.

2. The heat insulation ring as described in claim 1, characterized in that, The annular inclined surface can be a plane or a convex continuous curved surface.

3. The heat insulation ring as described in claim 2, characterized in that, Along the circumference of the heat insulation ring, the top of the annular inclined surface is not higher than the upper surface of the wafer tray.

4. The heat insulation ring as described in claim 1, characterized in that, During the process, the normal line at the bottom of the inclined surface of the first arc-shaped section intersects with the plate transfer gate. The normal to the bottom of the inclined surface of the second arc-shaped section intersects with the flow-limiting ring, which is located inside the reaction chamber and has an opening. The plate transfer gate is used to close the opening during the process.

5. The heat insulation ring as described in claim 4, characterized in that, The normal to the top of the annular inclined surface intersects with the top sealing plate.

6. The heat insulation ring as described in claim 5, characterized in that, The normal at the midpoint of the annular inclined surface along the circumference intersects with the top sealing plate.

7. The heat insulation ring as described in claim 1, characterized in that, The material of the first arc-shaped section is different from that of the second arc-shaped section, and the emissivity of the material of the first arc-shaped section is higher than that of the material of the second arc-shaped section.

8. The heat insulation ring as described in claim 1, characterized in that, The heater is an electromagnetic induction heating coil, and the conductivity of the material in the first arc-shaped section is higher than that of the material in the second arc-shaped section.

9. The heat insulation ring as described in claim 8, characterized in that, The first arc-shaped section is made of graphite, and the second arc-shaped section is made of quartz.

10. The heat insulation ring as described in claim 1, characterized in that, The color of the inclined surface of the first arc-shaped section is darker than the color of the inclined surface of the second arc-shaped section.

11. The heat insulation ring as described in claim 1, characterized in that, The surface roughness of the inclined surface of the first arc-shaped section is greater than the surface roughness of the inclined surface of the second arc-shaped section.

12. The heat insulation ring according to any one of claims 1-11, characterized in that, The heat insulation ring is a one-piece circular ring, and at least a portion of the bottom of the heat insulation ring has a groove.

13. The heat insulation ring as described in claim 12, characterized in that, The first arc-shaped section does not have the groove, while the second arc-shaped section has the groove.

14. The heat insulation ring according to any one of claims 1-11, characterized in that, The heat insulation ring is a circular ring composed of multiple arc-shaped segments.

15. The heat insulation ring as described in claim 14, characterized in that, At least one arc-shaped section has a groove at its bottom, the groove not penetrating the sidewalls at both ends of the arc-shaped section.

16. The heat insulation ring as described in claim 15, characterized in that, The first arc-shaped section does not have the groove, while the second arc-shaped section has the groove.

17. The heat insulation ring as described in claim 14, characterized in that, The material used in the arc-shaped section located in the region of lower temperature at the edge of the wafer tray has higher conductivity than the material used in the arc-shaped section located in the region of higher temperature at the edge of the wafer tray.

18. A chemical vapor deposition apparatus, characterized in that, include: reaction chamber; A top sealing plate is located at the top of the reaction chamber; A flow-limiting ring is located below the top sealing plate and has an opening thereon; A plate transfer gate is used to close the opening during the process; A wafer tray is located at the bottom of the reaction chamber, a heater is provided below the wafer tray, and a heat insulation ring as described in any one of claims 1 to 17 is provided on the outer side of the wafer tray.

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