Sample table for MPCVD equipment and MPCVD equipment

Abstract

The utility model relates to the technical field of plasma chemical vapor deposition, in particular to a sample table for MPCVD equipment and the MPCVD equipment. The sample table comprises a sample table main body and a heat conducting sheet, the sample table main body is provided with a front surface suitable for placing a substrate and a back surface suitable for contacting with the cooling table, and the front surface is provided with a substrate groove suitable for accommodating the substrate; the heat-conducting fin is arranged at the central position in the substrate groove and / or the central position of the back surface, and the heat conductivity of the heat-conducting fin is greater than that of the sample table main body. According to the sample table provided by the invention, the heat of the central area of the substrate is quickly conducted downwards by utilizing the high thermal conductivity of the heat conducting sheet, so that the heat distribution of each area of the substrate tends to be balanced, the uniformity of the surface temperature of the substrate can be improved, the formed diamond film is more uniform, and the performance and the quality of the formed diamond film are improved.

Description

Technical Field

[0001] This application relates to the field of plasma chemical vapor deposition technology, and in particular to a sample stage and MPCVD equipment for MPCVD equipment. Background Technology

[0002] Diamond is widely used in various fields due to its excellent properties. Among the many methods for synthesizing diamonds artificially, microwave plasma chemical vapor deposition (MPCVD) is considered the preferred method for preparing high-quality, large-size diamonds due to its advantages such as no discharge electrode contamination and good controllability. MPCVD equipment generally includes a microwave device, a vacuum device, a gas supply device, a cooling device, and a plasma reaction chamber. The plasma reaction chamber, as the core structure, includes components such as a reaction chamber, a water-cooled stage, and a sample stage. The water-cooled stage and the sample stage are located inside the reaction chamber. The front of the sample stage is used to place the substrate, and the back of the sample stage is located on the water-cooled stage, which dissipates heat from the substrate on the sample stage.

[0003] In the preparation of diamond using MPCVD technology, plasma is formed above the substrate, and the plasma deposits a diamond film on the substrate. Due to various factors such as the design of the reaction chamber structure, disturbances from the mixed growth gas, and the sample stage, the plasma spheres within the reaction chamber are prone to displacement and non-uniformity. This plasma non-uniformity leads to uneven heat distribution on the substrate, such as higher temperatures in the center and lower temperatures at the edges. This results in inconsistent diamond film growth rates across different regions of the substrate, leading to uneven diamond film thickness (especially in large-area diamond films), significant internal stress, and decreased performance. It also affects subsequent grinding and polishing of the diamond film, ultimately resulting in poor performance and quality of the formed diamond film. Summary of the Invention

[0004] The first objective of this application is to provide a sample stage for MPCVD equipment to solve the technical problems existing in the prior art, which are caused by uneven heat distribution on the substrate due to non-uniform plasma, resulting in inconsistent growth rates of diamond films, and thus causing defects such as uneven thickness and high internal stress in the formed diamond films.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] A sample stage for an MPCVD apparatus includes a sample stage body and a thermally conductive sheet, wherein: the sample stage body has a front side adapted for placing a substrate and a back side adapted for contacting a cooling stage, the front side having a substrate groove adapted to accommodate the substrate; the thermally conductive sheet is disposed at the center of the substrate groove and / or the center of the back side, and the thermal conductivity of the thermally conductive sheet is greater than the thermal conductivity of the sample stage body.

[0007] The sample stage provided in this application compensates for the characteristic of high heat distribution (or plasma ball distribution) in the center and low heat distribution at the edges of the substrate during the diamond film preparation process. By placing a heat-conducting plate at the center of the substrate groove and / or the center of the back of the sample stage body, and making the thermal conductivity of the heat-conducting plate greater than that of the sample stage body, the heat in the central area of ​​the sample stage can be quickly conducted outward or downward using the high thermal conductivity of the heat-conducting plate. This rapidly reduces the heat or temperature in the central area of ​​the sample stage, thereby reducing the temperature difference between different areas of the sample stage and making the temperature distribution more uniform. During the diamond film formation process, the structural design of this sample stage can make the heat distribution in different areas of the substrate placed on the sample stage tend to be balanced, improve the uniformity of temperature distribution on the substrate, improve the consistency of diamond film growth rate on the substrate, and make the thickness of the diamond film formed on the substrate more uniform and the internal stress lower, thus improving the performance and quality of the formed diamond film.

[0008] Furthermore, a heat-conducting plate mounting groove is provided within the substrate trench, and the heat-conducting plate is at least partially disposed within the heat-conducting plate mounting groove. Thus, by providing the heat-conducting plate mounting groove and placing at least part of the heat-conducting plate within it, the heat-conducting plate mounting groove can restrict the position of the heat-conducting plate relative to the sample stage body, preventing displacement of the heat-conducting plate and ensuring that its position is within the area where accelerated heat conduction is required. This further improves the effectiveness and reliability of the heat-conducting plate in regulating the temperature distribution of the sample stage.

[0009] Furthermore, the heat-conducting sheet is integrally disposed within the heat-conducting sheet mounting groove, and the upper end face of the heat-conducting sheet is coplanar with the bottom surface of the substrate groove. In this case, by making the upper end face of the heat-conducting sheet coplanar with the bottom surface of the substrate groove, there is no height difference between the heat-conducting sheet and the bottom of the substrate groove. When the substrate is placed on the front side of the sample stage, the center of the back side of the substrate can directly contact the heat-conducting sheet, and the edge of the back side of the substrate can directly contact the bottom of the substrate groove of the sample stage, so that the back side of the substrate is completely in contact with the placement surface. This can prevent plasma gas from entering the back side of the substrate, avoid the formation of a diamond film on the back side of the substrate, and prevent it from affecting the temperature distribution on the substrate, thereby improving the forming quality of the diamond film formed on the front side of the substrate. In addition, the absence of a height difference between the heat-conducting sheet and the bottom of the substrate groove can also make the sample stage more stable, preventing instability such as tilting when the substrate is placed on it.

[0010] Furthermore, the lower end of the heat-conducting sheet is disposed within the heat-conducting sheet mounting groove, and the upper end of the heat-conducting sheet protrudes from the bottom surface of the substrate groove. In this case, by making the upper end of the heat-conducting sheet protrude from the bottom surface of the substrate groove, when the substrate is placed in the substrate groove, the central region of the back side of the substrate is in direct contact with the heat-conducting sheet, and the edge region of the back side of the substrate forms a gap with the bottom surface of the substrate groove that can accommodate air. Since the thermal conductivity of air is low, typically lower than that of the sample stage body and the heat-conducting sheet, the heat dissipation effect at this gap is worse than that at the heat-conducting sheet. The high thermal conductivity of the heat-conducting sheet results in a fast heat dissipation rate. This allows the heat loss rate of the high-temperature region corresponding to the center of the substrate placed on the sample stage to be faster, and the heat loss rate of the low-temperature region corresponding to the edge to be slower, thereby making the heat distribution of each region of the substrate tend to be balanced. This results in a more uniform growth rate of the diamond film, making the thickness of the diamond film grown on it more uniform and the internal stress lower, thereby improving the performance and quality of the diamond film.

[0011] Furthermore, the equivalent diameter of the heat-conducting plate mounting groove is 30-40 mm; and / or, the axis of the heat-conducting plate mounting groove is offset from the axis of the substrate groove by 0-10 mm. Generally, the equivalent diameter of the heat-conducting plate mounting groove and its offset from the axis of the substrate groove can be adaptively adjusted according to the characteristics of the heat distribution on the substrate (or the characteristics of the plasma ball distribution). Here, controlling the equivalent diameter of the heat-conducting plate mounting groove within the range of 30-40 mm can more effectively ensure the heat transfer and heat dissipation efficiency at the center of the sample stage, making it suitable for substrates of most sizes, thus meeting the requirements of most diamond film sizes, improving the applicability of the sample stage, and eliminating the need to prepare multiple sample stages for different sizes, thereby saving on the manufacturing cost of diamond films. Similarly, by aligning the axis of the heat-conducting plate mounting groove with the axis of the substrate groove, or by having an offset of up to 10 mm, the heat transfer and heat dissipation efficiency at the center of the sample stage can be more effectively guaranteed, making it suitable for substrates of most sizes. This meets the requirements of most diamond film sizes, improves the applicability of the sample stage, eliminates the need to prepare multiple sample stages for different sizes, and has high applicability, thereby saving the manufacturing cost of diamond films.

[0012] Further, the depth of the heat-conducting plate mounting groove is 0.2-2 mm; and / or, the thickness of the heat-conducting plate is 0.5-2 mm. Preferably, the depth of the heat-conducting plate mounting groove is 0.2-0.5 mm; and / or, the thickness of the heat-conducting plate is 0.7-2 mm. Generally, the depth of the heat-conducting plate mounting groove or the thickness of the heat-conducting plate can be set according to actual needs, so that the heat-conducting plate is completely or partially accommodated in the heat-conducting plate mounting groove. Here, by setting the depth of the heat-conducting plate mounting groove to 0.2-2 mm or 0.2-0.5 mm, and the thickness of the heat-conducting plate to 0.5-2 mm or 0.7-2 mm, it is possible to avoid increasing the material usage for preparing the heat-conducting plate due to excessively deep grooves or excessively thick heat-conducting plates, while still accommodating the heat-conducting plate. This saves on the manufacturing cost of the sample stage, i.e., reduces the production cost of the diamond film and improves the practicality of the sample stage.

[0013] Furthermore, the heat-conducting sheet is made of diamond or silicon carbide; and / or, the ratio of the thermal conductivity of the heat-conducting sheet to the thermal conductivity of the sample stage body is greater than or equal to 2. Typically, the material of the heat-conducting sheet and the ratio of its thermal conductivity to that of the sample stage body can be adaptively adjusted according to the characteristics of heat distribution in the substrate during fabrication (or the characteristics of plasma ball distribution). Here, by setting the material of the heat-conducting sheet to diamond and silicon carbide, or by making the ratio of the thermal conductivity of the heat-conducting sheet to the thermal conductivity of the sample stage body greater than or equal to 2, it is possible to ensure that the heat-conducting sheet has a sufficiently high thermal conductivity to fully realize the effect of accelerating the thermal conductivity at the center of the sample stage. This makes the thermal conductivity at the center of the sample stage significantly greater than that at other locations on the sample stage, thereby significantly accelerating the heat conduction in the central region of the substrate placed on it, i.e., significantly greater than the heat conduction in the edge region. This compensates for the defect of high temperature in the central region and low temperature in the edge region of the substrate caused by thermal radiation from the plasma ball. By adjusting the thermal conduction rate, the temperature distribution of the sample stage or the substrate placed on it can be more effectively achieved, thereby enabling the diamond film deposited on the substrate to have a more consistent growth rate, improving the uniformity of the diamond film thickness and reducing internal stress, i.e., improving the performance and quality of the diamond film.

[0014] Furthermore, the heat-conducting sheet is positioned at the center of the substrate trench, with its upper end protruding from the bottom surface of the trench. In this configuration, when the substrate is placed in the trench, the central region of the substrate contacts the heat-conducting sheet, and a gap capable of accommodating air is formed between the edge region of the substrate and the bottom surface of the trench. Since the thermal conductivity of air is relatively low, generally lower than that of the sample stage body, and the thermal conductivity of the sample stage body is lower than that of the heat-conducting sheet, this air-accommodating gap further slows down the thermal conductivity of the edge region of the substrate, thereby further increasing the difference in thermal conductivity between the central and edge regions of the substrate. This more effectively compensates for the temperature difference between the substrate center and the edge formed by the plasma sphere above the substrate, resulting in a more uniform heat or temperature distribution on the substrate. This further ensures the uniformity of the diamond film thickness grown on the substrate and improves the film formation quality.

[0015] Furthermore, it also includes a support pad, the lower end face of which contacts the bottom surface of the substrate groove, and the upper end face of which is coplanar with the upper end face of the heat-conducting sheet; the sample stage body and the support pad are integrally formed or detachably connected. Thus, the support pad and the heat-conducting sheet can have the same height relative to the bottom surface of the substrate groove. When the substrate is placed on the sample stage, the support pad and the heat-conducting sheet can simultaneously support the substrate, making the substrate more stable and keeping it parallel and not tilted, so as to more effectively contact the plasma and more effectively form a diamond film on the substrate. In addition, by making the support pad and the sample stage body integrally formed, the position of the support pad can be set according to pre-required, thus simplifying the sample stage manufacturing process; by making the support pad and the sample stage body detachably connected, the position of the support pad in the substrate groove can be adjusted, thus adapting the position of the support pad to different substrate sizes, thereby improving the applicability of the sample stage.

[0016] Furthermore, the side of the support pad contacts the sidewall of the substrate trench, and the thickness of the support pad is less than the depth of the substrate trench. Thus, the support pad can be positioned at the edge of the sample stage, i.e., inside the sidewall of the substrate trench. By making the thickness of the support pad less than the depth of the substrate trench, the support pad and the sidewall of the substrate trench combine to form a stepped structure for placing the substrate. That is, the support pad supports the substrate, and the sidewall of the substrate trench limits its position. This stepped structure serves two purposes: firstly, it supports the substrate and prevents it from sliding; secondly, it seals the periphery of the gap formed between the substrate and the bottom surface of the substrate trench, preventing the occurrence of point discharge arcing in the gap between the substrate and the sample stage body during diamond deposition, or the deposition of a diamond film on the back side of the substrate. This eliminates the risk of diamond film cracking due to point discharge arcing and the influence of the diamond film formed on the back side of the substrate on the temperature distribution, thereby improving the quality and performance of the diamond film grown on the front side of the substrate.

[0017] Furthermore, the support pad is annular, and its width is 0.5-2 mm. Thus, by controlling the width of the support pad within the range of 0.5-2 mm, the substrate can be effectively supported without affecting the heat dissipation effect at the substrate's edge, ensuring the temperature regulation effect of the sample stage on the substrate and improving the uniformity of diamond film formation.

[0018] Furthermore, the height difference between the upper surface of the heat-conducting sheet and the bottom surface of the substrate trench is 0.5-2 mm. Therefore, by making the heat-conducting sheet 0.5-2 mm higher than the bottom of the substrate trench, an air gap can be formed between the back surface of the substrate and the bottom of the substrate trench when the substrate is placed on the sample stage, reducing the heat conduction rate in the substrate area corresponding to this gap. It also prevents the heat-conducting sheet from being too thick, causing the perimeter of the substrate to exceed the height of the substrate trench sidewall, which could lead to arcing and cracking of the diamond film.

[0019] The second objective of this application is to provide an MPCVD apparatus that includes the sample stage described in any of the preceding claims, thereby possessing at least all the technical effects of the aforementioned sample stage.

[0020] The above-described sample stage for MPCVD equipment and the MPCVD equipment containing it, by placing a heat-conducting plate at the center of the substrate groove of the sample stage and / or at the center of the back of the sample stage body, and making the thermal conductivity of the heat-conducting plate greater than that of the sample stage body, can utilize the high thermal conductivity of the heat-conducting plate to quickly conduct heat from the central area of ​​the sample stage outward or downward, thereby rapidly reducing the heat or temperature in the central area of ​​the sample stage. This reduces the temperature difference between different areas of the sample stage and makes the temperature distribution more uniform. During the diamond film formation process, the structural design of this sample stage can make the heat distribution of different areas of the substrate placed on the sample stage tend to be balanced, improve the uniformity of temperature distribution on the substrate, improve the consistency of diamond film growth rate on the substrate, and make the thickness of the diamond film formed on the substrate more uniform, the internal stress less, and improve the performance and quality of the formed diamond film. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the mounting structure of the sample stage, substrate, and cooling stage for an MPCVD equipment provided in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the mounting structure of the sample stage, substrate, and cooling stage for an MPCVD equipment provided in another embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the structure of a sample stage for an MPCVD device provided in an embodiment of this application;

[0025] Figure 4 This is a schematic diagram of the structure of a sample stage for an MPCVD device provided in another embodiment of this application;

[0026] Figure 5 This is a schematic diagram of the structure of a sample stage for an MPCVD device provided in another embodiment of this application.

[0027] icon:

[0028] 1-Sample stage body; 11-Substrate groove; 12-Heat-conducting sheet mounting groove;

[0029] 2-Heat-conducting sheet;

[0030] 3-Support pad;

[0031] 100-substrate;

[0032] 200-Cooling platform. Detailed Implementation

[0033] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] It should be noted that in the description of this application, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] It should be noted that, in the description of this application, the terms "connection" and "installation" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0036] To address the technical problem of uneven diamond film growth rate due to uneven substrate heat distribution, resulting in diamond films with defects such as uneven thickness and high internal stress, this application provides, in one embodiment, a sample stage for an MPCVD device, referring to... Figure 1 and Figure 2 The sample stage includes a sample stage body 1 and a heat-conducting plate 2, wherein: the sample stage body 1 has a front side suitable for placing a substrate 100 and a back side suitable for contacting the cooling stage 200, and the front side is provided with a substrate groove 11 suitable for accommodating the substrate 100; the heat-conducting plate 2 is disposed at the center position in the substrate groove 11 and / or the center position on the back side, and the thermal conductivity of the heat-conducting plate 2 is greater than the thermal conductivity of the sample stage body 1.

[0037] The cooling stage 200 is typically a water-cooled stage made of copper or molybdenum. The sample stage is placed entirely on the cooling stage 200, with the back of the sample stage body 1 in contact with the cooling stage 200. For example... Figure 1As shown, when the heat-conducting plate 2 is positioned at the center of the substrate groove 11, the heat-conducting plate 2 is located between the substrate 100 and the sample stage body 1. Figure 2 As shown, when the heat-conducting plate 2 is positioned at the center of the back side of the sample stage body 1, the heat-conducting plate 2 is located between the sample stage body 1 and the cooling stage 200. Both of these structures can utilize the high thermal conductivity of the heat-conducting plate 2 to rapidly conduct heat from the central region of the substrate 100 downwards, making the heat distribution in different regions of the substrate 100 more balanced. This improves the uniformity of the surface temperature of the substrate 100, resulting in a more uniform diamond film and enhancing the performance and quality of the formed diamond film.

[0038] Furthermore, since the heat conduction rate at the center of the sample stage body 1 is faster, the heat at the center of the sample stage body 1 can be quickly conducted to the edge to reduce the high temperature effect at the center as soon as possible. At the same time, the heat conduction rate at the edge of the sample stage body 1 is slower, making it less likely for heat to be lost. Combined with the heat conducted from the center, it can effectively compensate for the low temperature at the edge, thereby making the temperature distribution uniform across the entire sample stage body 1. This ensures that the substrate 100 placed on it can be heated uniformly, thus depositing a more uniform diamond film on it.

[0039] Furthermore, continue to refer to Figure 1 When the heat-conducting plate 2 is positioned at the center of the bottom of the substrate groove 11, it can directly contact the central area of ​​the bottom of the substrate 100. This arrangement allows the heat-conducting plate 2 to quickly conduct heat from the central area of ​​the substrate 100 to the edges; it also allows it to quickly conduct heat from the central area of ​​the substrate 100 to the sample stage body 1 below, and then to the cooling stage 200. This improves the uniformity of the surface temperature of the substrate 100, thereby enhancing the thickness uniformity and quality of the formed diamond film. Furthermore, the back surface of the sample stage body 1 is a flat plane, allowing for close contact with the cooling stage 200, which facilitates uniform heat diffusion.

[0040] Continue to refer to Figure 2 When the heat-conducting plate 2 is located at the center of the back of the sample stage body 1, the heat-conducting plate 2 is embedded in the sample stage body 1 as a whole, and the bottom surface of the heat-conducting plate 2 is coplanar with the bottom surface of the sample stage body 1, so that both are in close contact with the cooling stage 200.

[0041] Furthermore, in some embodiments, there can be two or more heat-conducting sheets 2, simultaneously positioned at the center of the substrate trench 11 and at the center of the back surface of the sample stage body 1. This further enhances the heat conduction rate at the center of the sample stage, meeting the higher requirements for heat conduction rate in the central region of the substrate.

[0042] In some other embodiments, a limiting protrusion is provided on the bottom surface of the substrate trench 11, and the heat-conducting sheet 2 is disposed within the limiting protrusion. Thus, the position of the heat-conducting sheet can be limited by the limiting protrusion, preventing the heat-conducting sheet from sliding or shifting.

[0043] It should be noted that the sample stage provided in this application can be used to prepare single-crystal or polycrystalline diamond films, as well as various other metal films, amorphous inorganic films, and organic films. The application of this sample stage is not limited here.

[0044] It should also be noted that the center position described in this application is relative to the edge position; that is, the center position is located inside the edge position, and it is not necessarily the position of the symmetry axis of the edge position. It can also be a position slightly to the left or right. For example, the center position can refer to the center (axis position) of the entire sample stage, or it can be a position that deviates from the axis to the left or right. Similarly, the edge position described in this application is the position close to the edge of the sample stage, which can be either the outermost edge of the sample stage or an edge slightly inside the outermost edge. As for the specific location of the center position and the edge position, they can be adaptively adjusted according to the actual needs, such as the characteristics of the plasma ball distribution, to ensure uniform heat distribution on the substrate 100 placed on the sample stage.

[0045] In this embodiment, the sample stage body 1 has an overall cylindrical structure and is made of molybdenum or tungsten. Since molybdenum has the advantages of both high temperature resistance and relatively low price, it is preferred that the sample stage body 1 be made of molybdenum.

[0046] As an optional embodiment, the heat-conducting sheet 2 is made of diamond or silicon carbide. Generally, depending on the manufacturing process, the thermal conductivity of diamond ranges from 600 to 2000 W / mK; the thermal conductivity of silicon carbide is around 450 W / mK; and the thermal conductivity of molybdenum is around 142 W / mK. Due to the ultra-high thermal conductivity of diamond, it is preferred that the heat-conducting sheet 2 be made of diamond.

[0047] As an optional embodiment, the ratio of the thermal conductivity of the heat-conducting sheet 2 to the thermal conductivity of the sample stage body 1 is greater than or equal to 2. This ratio can be adaptively adjusted according to the characteristics of the heat distribution (or the characteristics of the plasma ball distribution) of the substrate 100 during the fabrication process. For example, the larger the ratio of the heat value of the central region to the edge region of the substrate 100 during the fabrication process, the larger the ratio of the thermal conductivity of the heat-conducting sheet 2 to the thermal conductivity of the sample stage body 1.

[0048] In the above embodiments, by setting the material of the heat-conducting sheet 2 to diamond and silicon carbide, or by making the ratio of the thermal conductivity of the heat-conducting sheet 2 to the thermal conductivity of the sample stage body 1 greater than or equal to 2, it can be ensured that the heat-conducting sheet 2 has a sufficiently high thermal conductivity to fully achieve the effect of accelerating the thermal conductivity at the center of the sample stage, making the thermal conductivity at the center of the sample stage significantly greater than that at other positions of the sample stage. This results in a significant acceleration of thermal conduction in the central region of the substrate 100 placed on it, i.e., significantly greater than the thermal conduction in the edge region. This compensates for the defect of high temperature in the central region and low temperature in the edge region of the substrate 100 caused by thermal radiation from the plasma ball, etc. By adjusting the thermal conduction rate, the temperature uniformity of the sample stage or the substrate 100 placed on it can be more effectively achieved, thereby making the diamond film deposited on the substrate 100 have a more consistent growth rate, improving the uniformity of the diamond film thickness and reducing internal stress, i.e., improving the performance and quality of the diamond film.

[0049] Continue to refer to Figure 1 and Figure 3 In the embodiment where the heat-conducting plate 2 is disposed within the substrate groove 11, a heat-conducting plate mounting groove 12 is provided within the substrate groove 11, and the heat-conducting plate 2 is at least partially disposed within the heat-conducting plate mounting groove 12. Therefore, by providing the heat-conducting plate mounting groove 12 and disposing of the heat-conducting plate 2 at least partially within it, the heat-conducting plate mounting groove 12 can restrict the position of the heat-conducting plate 2 relative to the sample stage body 1, preventing the heat-conducting plate 2 from shifting. This ensures that the position of the heat-conducting plate 2 is within the area where accelerated heat conduction is required, further improving the effectiveness and reliability of the heat-conducting plate 2 in regulating the temperature distribution of the sample stage.

[0050] like Figure 1 As shown, in an optional embodiment, the heat-conducting sheet 2 is entirely disposed within the heat-conducting sheet mounting groove 12, and the upper end surface of the heat-conducting sheet 2 is coplanar with the bottom surface of the substrate groove 11. In this case, by making the upper end surface of the heat-conducting sheet 2 coplanar with the bottom surface of the substrate groove 11, there is no height difference between the heat-conducting sheet 2 and the bottom of the substrate groove 11. When the substrate 100 is placed on the front side of the sample stage, the center of the back side of the substrate 100 can directly contact the heat-conducting sheet 2, and the edge of the back side of the substrate 100 can directly contact the bottom of the substrate groove 11 of the sample stage, so that the back side of the substrate 100 is completely in contact with the placement surface. This can prevent plasma gas from entering the back side of the substrate 100, avoid the formation of a diamond film on the back side of the substrate 100, and thus avoid affecting the temperature distribution on the substrate, thereby improving the forming quality of the diamond film formed on the front side of the substrate 100. In addition, the absence of a height difference between the heat-conducting sheet 2 and the bottom of the substrate groove 11 can also make the sample stage more stable, preventing instability such as tilting when the substrate 100 is placed on it.

[0051] like Figure 3As shown, in another optional embodiment, the lower end of the heat-conducting sheet 2 is disposed within the heat-conducting sheet mounting groove 12, and the upper end of the heat-conducting sheet 2 protrudes beyond the bottom surface of the substrate groove 11. In this case, by making the upper end of the heat-conducting sheet 2 protrude beyond the bottom surface of the substrate groove 11, when the substrate 100 is placed into the substrate groove 11, the central region of the back surface of the substrate 100 is in direct contact with the heat-conducting sheet 2, and the edge region of the back surface of the substrate 100 forms a gap with the bottom surface of the substrate groove 11 that can accommodate air. Because air has a low thermal conductivity, typically lower than that of the sample stage body 1 and the heat-conducting plate 2, the heat dissipation effect at this gap is worse than that at the heat-conducting plate 2. The high thermal conductivity of the heat-conducting plate 2 results in a faster heat dissipation rate. This allows the heat loss rate of the high-temperature region corresponding to the center of the substrate 100 placed on the sample stage to be faster, while the heat loss rate of the low-temperature region corresponding to the edge is slower. This makes the heat distribution of each region of the substrate 100 tend to be balanced, so that the diamond film has a more uniform growth rate, resulting in a more uniform thickness and lower internal stress of the diamond film grown on it, thereby improving the performance and quality of the diamond film.

[0052] As an optional embodiment, the diameter of the substrate trench 11 is greater than or equal to the diameter of the substrate 100. To facilitate the placement of the substrate 100 into the substrate trench 11, the diameter of the substrate trench 11 is greater than the diameter of the substrate 100.

[0053] As an optional embodiment, the depth of the substrate trench 11 is greater than or equal to the thickness of the substrate 100. In other embodiments, the sum of the thickness of the substrate 100 and the thickness of the heat-conducting sheet 2 is less than or equal to the depth of the substrate trench 11. Therefore, when the substrate is placed on the sample stage, the substrate 100 can be completely embedded within the substrate trench 11, preventing the edges of the substrate 100 from being exposed. This prevents arcing / discharge phenomena at the edges of the substrate 100, which could lead to cracking of the diamond film grown on the front side of the substrate 100, thus affecting the quality of the diamond film formation.

[0054] In some embodiments, the depth of the substrate trench 11 can be 2-10 mm. In other embodiments, the diameter of the substrate trench 11 can be 40-120 mm. In still other embodiments, the depth of the substrate trench 11 can be 2-10 mm, and the diameter of the substrate trench 11 can be 40-120 mm. Considering that the thickness of typical deposited samples varies from 1.5-6 mm, the depth of the substrate trench 11 can be set to 2-10 mm. The depth of the substrate trench 11 should be greater than the thickness of the substrate 100 so that the substrate 100 can be completely embedded in the substrate trench 11, preventing arcing / discharge phenomena and improving the quality of the diamond film deposited on the substrate. Considering that the diameter of typical substrate samples varies from 50-100 mm, such as 50.8 mm or 76.2 mm, the diameter of the substrate trench 11 can be set to 40-120 mm. This diameter range is suitable for most deposited samples, thereby improving the applicability of the sample stage.

[0055] Furthermore, if the diameter difference between the substrate groove 11 and the substrate 100 is too small, it will be difficult or even impossible for the substrate 100 to be placed into the substrate groove 11. If the difference is too large, gas will deposit on the peripheral surface of the substrate 100 or through the edge of the substrate 100 to the back surface of the substrate 100 to form a diamond film, affecting the temperature distribution, the overall internal stress of the diamond film, etc., and thus affecting the film formation quality of the diamond film. Based on the above considerations, in some embodiments, the diameter difference between the substrate groove 11 and the diameter of the substrate 100 is 0.5-1 mm. This diameter difference range facilitates the placement or removal of the substrate 100 from the substrate groove 11, and also avoids gas deposition on the peripheral surface of the substrate 100 or through the edge of the substrate 100 to the back surface of the substrate 100 to form a diamond film, which would interfere with the temperature distribution when the diamond film is deposited on the front surface of the substrate 100, thereby improving the film formation quality and the performance and quality of the diamond film.

[0056] In some embodiments, the difference between the depth of the substrate trench 11 and the thickness of the substrate 100 can be 0.5-2 mm. In other embodiments, the difference between the sum of the thicknesses of the substrate 100 and the heat-conducting sheet 2 and the depth of the substrate trench 11 can be 0.5-2 mm. This range of depth and thickness difference can more effectively prevent the edges of the substrate 100 from being exposed, and also facilitates the placement and removal of the substrate 100.

[0057] Taking all the above into consideration, preferably, the diameter of the substrate trench 11 is 50-105 mm and the depth of the substrate trench 11 is 3-8 mm. This size range is applicable to most deposited samples.

[0058] It should be noted that the size of the substrate trench 11 can be adaptively adjusted according to the substrate 100 to be prepared, and is not limited to the above-mentioned size.

[0059] Continue to refer to Figure 1In some embodiments, the equivalent diameter of the heat-conducting plate mounting groove 12 can be 30-40 mm; and / or, the axis of the heat-conducting plate mounting groove 12 can be offset from the axis of the substrate groove 11 by 0-10 mm. Generally, the equivalent diameter of the heat-conducting plate mounting groove 12 and its offset from the axis of the substrate groove 11 can be adaptively adjusted according to the characteristics of the heat distribution on the substrate (or the characteristics of the plasma ball distribution). Here, controlling the equivalent diameter of the heat-conducting plate mounting groove 12 within the range of 30-40 mm can more effectively ensure the heat transfer and heat dissipation efficiency at the center of the sample stage, making it suitable for substrates of most sizes, thereby meeting the requirements of most diamond film sizes, improving the applicability of the sample stage, eliminating the need to prepare multiple sample stages for different sizes, and saving on the manufacturing cost of diamond films. Similarly, by aligning the axis of the heat-conducting plate mounting groove 12 with the axis of the substrate groove 11, or by having an offset of up to 10 mm, the heat transfer and heat dissipation efficiency at the center of the sample stage can be more effectively guaranteed, making it suitable for substrates of most sizes. This satisfies the requirements of most diamond film sizes, improves the applicability of the sample stage, eliminates the need to prepare multiple sample stages according to different sizes, and has high applicability, thereby saving the manufacturing cost of diamond films.

[0060] In some embodiments, the depth of the heat-conducting plate mounting groove 12 can be 0.2-2 mm, and exemplarily, the depth of the heat-conducting plate mounting groove 12 can be 0.2-0.5 mm. In other embodiments, the thickness of the heat-conducting plate 2 can be 0.5-2 mm, and exemplarily, the thickness of the heat-conducting plate 2 can be 0.7-2 mm. Generally, the depth of the heat-conducting plate mounting groove 12 or the thickness of the heat-conducting plate 2 can be set according to actual needs, so that the heat-conducting plate 2 is completely or partially accommodated in the heat-conducting plate mounting groove 12. Here, by setting the depth of the heat-conducting plate mounting groove 12 to 0.2-2 mm or 0.2-0.5 mm, and the thickness of the heat-conducting plate 2 to 0.5-2 mm or 0.7-2 mm, it is possible to accommodate the heat-conducting plate 2 without increasing the material usage for preparing the heat-conducting plate 2 due to excessively deep grooves or excessively thick heat-conducting plate 2, thereby saving the manufacturing cost of the sample stage, i.e., reducing the production cost of the diamond film and improving the practicality of the sample stage.

[0061] Continue to refer to Figure 4 and Figure 5The heat-conducting plate 2 is located at the center of the substrate groove 11, with its upper end protruding from the bottom surface of the substrate groove 11. In this case, when the substrate 100 is placed in the substrate groove 11, the central region of the substrate 100 contacts the heat-conducting plate 2, and a gap that can accommodate air is formed between the edge region of the substrate 100 and the bottom surface of the substrate groove 11. Since the thermal conductivity of air is relatively low, generally lower than that of the sample stage body 1, and the thermal conductivity of the sample stage body 1 is lower than that of the heat-conducting plate 2, this gap that accommodates air further slows down the thermal conductivity of the edge region of the substrate 100, thereby further increasing the difference in thermal conductivity between the central region and the edge region of the substrate 100. This more effectively compensates for the difference in temperature between the center and the edge of the substrate formed by the plasma sphere above the substrate 100, resulting in a more uniform heat or temperature distribution on the substrate 100, further ensuring the uniformity of the thickness of the diamond film grown on it, and improving the film quality.

[0062] In some embodiments, the sample stage further includes a support pad 3, the lower end face of which contacts the bottom surface of the substrate groove 11, and the upper end face of which is coplanar with the upper end face of the heat-conducting sheet 2. The support pad 3 is used to contact and support the substrate 100, and the upper end face of the support pad 3 and the upper end face of the heat-conducting sheet 2 should be flush, with a height error between them of less than 50 μm. This allows the support pad 3 and the heat-conducting sheet 2 to have the same height relative to the bottom surface of the substrate groove 11. When the substrate 100 is placed on the sample stage, the support pad 3 and the heat-conducting sheet 2 can simultaneously support the substrate 100, making the substrate 100 more stable and parallel without tilting, thus facilitating more effective contact with the plasma and more effective formation of a diamond film on the substrate 100.

[0063] In some embodiments, the support pad 3 is annular and is located between the edge of the substrate 100 and the bottom surface of the substrate trench 11. In other embodiments, the side of the support pad 3 contacts the sidewall of the substrate trench 11, and the thickness of the support pad 3 is less than the depth of the substrate trench 11. Therefore, the support pad 3 can be placed at the edge of the sample stage, that is, inside the side wall of the substrate groove 11. By making the thickness of the support pad 3 less than the depth of the substrate groove 11, the support pad 3 and the side wall of the substrate groove 11 combine to form a stepped structure for placing the substrate 100. That is, the support pad 3 supports the substrate 100, and the side wall of the substrate groove 11 limits the substrate 100. The combined stepped structure can, on the one hand, support the substrate 100 and prevent the substrate 100 from sliding. On the other hand, it can also seal the periphery of the gap formed between the substrate 100 and the bottom surface of the substrate groove 11, preventing the phenomenon of tip discharge arcing of plasma in the gap between the substrate 100 and the sample stage body 1 during the diamond deposition process, or the deposition of diamond film on the back of the substrate 100. This eliminates the hidden danger of diamond film cracking caused by tip discharge arcing and the influence of the diamond film generated on the back of the substrate 100 on the temperature distribution, thereby improving the quality and performance of the diamond film grown on the front of the substrate 100.

[0064] In some embodiments, such as Figure 4 As shown, the sample stage body 1 and the support pad 3 are integrally formed. This integrally formed structure avoids deformation of the support pad 3 and eliminates the need to consider the matching degree between the support pad 3 and the substrate groove 11 during processing, thus reducing the manufacturing difficulty of the sample stage. On the other hand, it completely eliminates the gap at the junction of the support pad 3 and the substrate groove 11, thereby avoiding poor contact or voids between the substrate 100 and the support pad 3, which is beneficial to the growth of diamond on the substrate 100.

[0065] In some embodiments, such as Figure 5 As shown, the sample stage body 1 and the support pad 3 are detachably connected. The advantage of this embodiment is that different thicknesses of heat-conducting sheets 2 can be selected according to specific temperature control requirements, and support pads 3 of different heights can be matched to these different thicknesses. Therefore, different temperature control requirements can be met without replacing the sample stage, simplifying the molding process. Furthermore, by making the support pad 3 and the sample stage body 1 detachably connected, the position of the support pad 3 within the substrate groove 11 can be adjusted. Thus, the position of the support pad 3 can be adaptively adjusted according to the size of the substrate 100, thereby improving the applicability of the sample stage.

[0066] The wider the support pad 3, the greater the contact width between the support pad 3 and the substrate 100. A wider contact width results in better heat dissipation at the edge of the substrate 100, leading to a greater temperature difference between the edge and center of the substrate 100. Conversely, if the support pad 3 is too narrow, the contact width between the support pad 3 and the substrate 100 will be too small, affecting the support effect and potentially causing plasma to discharge and spark at its tip within the gap between the substrate 100 and the substrate trench 11.

[0067] Based on the above considerations, in some embodiments, the width of the support pad 3 can be 0.5-2 mm. For example, the width of the support pad 3 can be 0.5 mm, 1 mm, 1.5 mm, or 2 mm. Thus, by controlling the width of the support pad 3 within the range of 0.5-2 mm, the substrate 100 can be effectively supported without affecting the heat dissipation effect at the edge of the substrate 100, thereby ensuring the temperature regulation effect of the sample stage on the substrate 100 and improving the uniformity of diamond film formation.

[0068] As an optional embodiment, the height difference between the upper surface of the heat-conducting sheet 2 and the bottom surface of the substrate groove 11 is 0.5-2mm. Therefore, by making the heat-conducting sheet 2 0.5-2mm higher than the bottom of the substrate groove 11, it is possible to ensure that an air gap is formed between the back surface of the substrate 100 and the bottom of the substrate groove 11 when the substrate 100 is placed on the sample stage, thereby reducing the heat conduction rate in the area of ​​the substrate 100 corresponding to this gap. It also prevents the heat-conducting sheet 2 from being too thick, causing the perimeter height of the substrate 100 to exceed the height of the sidewall of the substrate groove 11 after it is placed on it, which could easily lead to sparking and other phenomena at the edges of the substrate 100, resulting in cracking of the diamond film.

[0069] Another embodiment of this application provides an MPCVD apparatus, which includes the sample stage described in any of the above embodiments. Therefore, this MPCVD apparatus at least possesses the technical features and all the corresponding technical effects of the sample stage described above, which will not be repeated here.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A sample stage for an MPCVD equipment, characterized in that, Includes a sample stage body (1) and a heat-conducting plate (2), wherein: The sample stage body (1) has a front side suitable for placing a substrate (100) and a back side suitable for contacting a cooling stage (200), and the front side is provided with a substrate groove (11) suitable for accommodating the substrate (100). The heat-conducting sheet (2) is disposed at the center position of the substrate groove (11) and / or the center position of the back side, and the thermal conductivity of the heat-conducting sheet (2) is greater than the thermal conductivity of the sample stage body (1).

2. The sample stage for MPCVD equipment according to claim 1, characterized in that, A heat-conducting plate mounting groove (12) is provided in the substrate groove (11), and the heat-conducting plate (2) is at least partially disposed in the heat-conducting plate mounting groove (12).

3. The sample stage for MPCVD equipment according to claim 2, characterized in that, The heat-conducting sheet (2) is integrally disposed in the heat-conducting sheet mounting groove (12), and the upper end surface of the heat-conducting sheet (2) is coplanar with the bottom surface of the substrate groove (11); Alternatively, the lower end of the heat-conducting sheet (2) is located in the heat-conducting sheet mounting groove (12), and the upper end of the heat-conducting sheet (2) protrudes from the bottom surface of the substrate groove (11).

4. The sample stage for an MPCVD equipment according to claim 2, characterized in that, The depth of the heat-conducting plate mounting groove (12) is 0.2-2mm; And / or, the equivalent diameter of the heat-conducting plate mounting groove (12) is 30-40 mm; And / or, the axis of the heat-conducting plate mounting groove (12) is offset from the axis of the substrate groove (11) by 0-10 mm; And / or, the thickness of the heat-conducting sheet (2) is 0.5-2 mm.

5. The sample stage for an MPCVD equipment according to claim 1, characterized in that, The heat-conducting sheet (2) is made of diamond or silicon carbide. And / or, the ratio of the thermal conductivity of the heat-conducting sheet (2) to the thermal conductivity of the sample stage body (1) is greater than or equal to 2.

6. The sample stage for an MPCVD apparatus according to any one of claims 1 to 5, characterized in that, The heat-conducting sheet (2) is located at the center of the substrate groove (11), with its upper end protruding from the bottom surface of the substrate groove (11).

7. The sample stage for an MPCVD equipment according to claim 6, characterized in that, It also includes a support pad (3), the lower end face of which is in contact with the bottom surface of the substrate groove (11), and the upper end face of the support pad (3) is coplanar with the upper end face of the heat-conducting sheet (2). The sample stage body (1) and the support pad (3) are integrally formed or detachably connected.

8. The sample stage for an MPCVD equipment according to claim 7, characterized in that, The side of the support pad (3) is in contact with the side wall of the substrate groove (11), and the thickness of the support pad (3) is less than the depth of the substrate groove (11).

9. The sample stage for an MPCVD apparatus according to claim 7, characterized in that, The support pad (3) is annular, and the width of the support pad (3) is 0.5-2mm.

10. The sample stage for an MPCVD apparatus according to claim 6, characterized in that, The height difference between the upper end face of the heat-conducting sheet (2) and the bottom surface of the substrate groove (11) is 0.5-2mm.

11. An MPCVD device, characterized in that, Includes the sample stage as described in any one of claims 1 to 10.

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