Diamond electrostatic chuck and method of making same

Abstract

The application provides a diamond electrostatic chuck and a preparation method thereof, and relates to the technical field of electrostatic chucks. A diamond film is prepared on a silicon-based dielectric layer of the electrostatic chuck, so that the electrostatic chuck has excellent corrosion resistance, high insulation performance, better heat conductivity and a longer service life. Specifically, the silicon-based dielectric layer of the electrostatic chuck is pretreated to obtain an initial silicon-based dielectric layer after pretreatment, then a 915MHz microwave plasma chemical vapor deposition device is used in combination with deposition process parameters to deposit a diamond film on the first surface, the side surface, the thimble hole and the second surface of the silicon-based dielectric layer in stages, so that the overall insulation and heat conductivity of the electrostatic chuck are ensured.

Description

Technical Field

[0001] This application relates to the field of electrostatic chuck technology, and more specifically, to a diamond electrostatic chuck and its preparation method. Background Technology

[0002] As semiconductor manufacturing processes evolve towards 3nm and below nodes, and wafer sizes expand to 8-12 inches, the demand for larger area and higher performance in electrostatic chucks (ESCs), which are core clamping components in etching, CVD, and other equipment, is becoming increasingly urgent. Currently, most mainstream ESCs use alumina, aluminum nitride, or anodized aluminum alloys as the insulating layer, but these have limited thermal conductivity, insufficient resistance to plasma corrosion, and it is difficult to balance surface roughness with dielectric / thermal conductivity. Diamond films, with their high thermal conductivity (>2000 W / m·K), excellent insulation, and corrosion resistance, are an ideal alternative material.

[0003] However, applying diamond to large-size (i.e., 8-inch to 12-inch) electrostatic chucks presents three major challenges: (1) Uniform deposition over a large area: Traditional 2.45GHz MPCVD is limited by the size of the plasma ball, making it difficult to obtain uniform thickness, grain size, and crystal quality (sp³ / sp² carbon bond ratio) on large-size substrates; (2) Covering complex three-dimensional structures: The ESC surface has pin holes, and existing technologies have failed to effectively cover the inner walls of the pin holes with diamond films. Moreover, the edges of the pin holes are prone to forming sharp points due to electric field concentration and film accumulation, increasing the risk of electrostatic discharge; (3) Balancing surface roughness with electrical / thermal properties: Diamond films used for optical windows require extremely high transmittance and low scattering, and usually need to be grown as single crystals or extremely smooth polycrystalline surfaces (Ra<10nm). However, the requirements for diamond films in electrostatic chuck applications are quite different. On the one hand, to obtain optimal wafer adhesion (especially when Coulomb force and Johannesson-Labec force are combined), a certain surface roughness is required to increase the effective contact area and "biting" effect. On the other hand, excessive roughness can exacerbate localized plasma discharge, increase the risk of particulate contamination, and may affect the contact of ultrathin wafers. Therefore, it is necessary to precisely control the grain size, orientation, and surface morphology of the diamond film to achieve an "optimal" surface roughness range (typically Ra 0.1 μm-1 μm) while ensuring excellent insulation and high thermal conductivity. Therefore, a preparation method that can systematically solve the above problems is urgently needed. Summary of the Invention

[0004] The purpose of this application is to provide a diamond electrostatic chuck and its preparation method, which can achieve uniform and large-area diamond deposition of the electrostatic chuck, effectively cover the three-dimensional complex structure of the electrostatic chuck, balance the surface roughness to meet the application requirements, and improve the thermal conductivity and plasma corrosion resistance of the diamond dielectric layer.

[0005] In a first aspect, this application provides a method for preparing a diamond electrostatic chuck, comprising: The silicon-based dielectric layer of the electrostatic chuck is pretreated to obtain a pretreated silicon-based dielectric layer, wherein a pin hole penetrating the silicon-based dielectric layer is provided on the silicon-based dielectric layer. A first-stage deposition is performed based on the pretreated silicon-based dielectric layer to form an initial diamond film on the first surface of the silicon-based dielectric layer and the inner wall of the pin hole. A second-stage deposition is performed on the surface of the initial diamond film, the inner wall of the pin hole, and the side of the silicon-based dielectric layer to form a first diamond film; The silicon-based dielectric layer is flipped to perform a third-stage deposition based on the second surface of the silicon-based dielectric layer, resulting in the electrostatic chuck with a diamond protective film. The diamond protective film includes the initial diamond film, the first diamond film, and the second diamond film, wherein the second diamond film is the diamond film formed during the third-stage deposition.

[0006] By employing a phased and multi-angle deposition strategy, the problems of large-area uniform deposition, ineffective coverage of diamond films by complex three-dimensional structures, and difficulty in achieving the required surface roughness of diamond films to meet the requirements of electrostatic chuck use were systematically solved in the preparation of large-size diamond electrostatic chucks.

[0007] Optionally, the pretreatment of the silicon-based dielectric layer of the electrostatic chuck to obtain a pretreated silicon-based dielectric layer includes: Obtain the silicon-based dielectric layer of the electrostatic chuck; The silicon-based dielectric layer is cleaned to remove contaminants, resulting in a cleaned target silicon-based dielectric layer. Diamond powder is used to wipe the first surface, the second surface, the side surface, and the pin hole of the target silicon-based dielectric layer to form a seed layer on the target silicon-based dielectric layer, thereby obtaining the pretreated silicon-based dielectric layer.

[0008] The pretreatment step ensured good bonding between the diamond film and the silicon-based dielectric layer, and provided a uniform seed layer for subsequent deposition.

[0009] Optionally, the first-stage deposition based on the pretreated silicon-based dielectric layer to form an initial diamond film on the first surface of the silicon-based dielectric layer and the inner wall of the pin hole includes: The pretreated silicon-based dielectric layer is placed on a preset first molybdenum support device, and the first molybdenum support device is placed in a 915MHz microwave plasma chemical vapor deposition equipment. The first molybdenum support device is used to wrap and fit the side and second surface of the silicon-based dielectric layer to expose the first surface of the silicon-based dielectric layer and the inner wall of the pin hole. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the first deposition process parameters are controlled to perform the first stage deposition of the silicon-based dielectric layer, so as to form the initial diamond film on the first surface of the silicon-based dielectric layer and the inner wall of the pin hole.

[0010] The first-stage deposition process forms a highly uniform initial diamond film on the first surface of the chuck, laying the foundation for subsequent film growth.

[0011] Optionally, the first deposition process parameters are set as follows: the gas pressure range of the chamber is 10kPa-20kPa, the microwave power range is 30kW-35kW, and the temperature range of the silicon-based dielectric layer is 850℃-900℃. The flow rate of hydrogen is in the range of 2000 sccm-2300 sccm, the flow rate of methane is in the range of 32 sccm-35 sccm, and the flow rate of oxygen is in the range of 0.5 sccm-0.8 sccm.

[0012] Optionally, the second-stage deposition to form the first diamond film on the surface of the initial diamond film, the inner wall of the pin hole, and the side surface of the silicon-based dielectric layer includes: The silicon-based dielectric layer having the initial diamond film is placed on a pre-set second molybdenum support device, and the second molybdenum support device is placed in a 915MHz microwave plasma chemical vapor deposition equipment. The second molybdenum support device is used to support the silicon-based dielectric layer to expose the first surface of the silicon-based dielectric layer, the inner wall of the pin hole and the side surface. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the second deposition process parameters are controlled to perform a second-stage deposition on the surface of the initial diamond film, the inner wall of the pin hole, and the side of the silicon-based dielectric layer, so as to form the first diamond film on the first surface of the silicon-based dielectric layer, the inner wall of the pin hole, and the side.

[0013] Optionally, the second deposition process parameters are set as follows: the gas pressure in the chamber is 10kPa-20kPa, the microwave power is 30kW-35kW, and the temperature range of the silicon-based dielectric layer is 850℃-900℃. The flow rate of hydrogen is 2000 sccm-2300 sccm, the flow rate of methane is 32 sccm-35 sccm, and the flow rate of oxygen is 0.5 sccm-0.8 sccm.

[0014] Optionally, the deposition time range for the first stage of deposition is 16-20 hours, and the deposition time range for the second stage of deposition is 3-5 hours.

[0015] Optionally, the silicon-based dielectric layer is flipped to perform a third-stage deposition based on the second surface of the silicon-based dielectric layer, resulting in the electrostatic chuck with a diamond protective film. The diamond protective film includes the initial diamond film, the first diamond film, and the second diamond film. The second diamond film is the diamond film formed during the third-stage deposition and includes: The silicon-based dielectric layer with the first diamond film is flipped over and placed on a pre-set second molybdenum support device. The second molybdenum support device is placed in a 915MHz microwave plasma chemical vapor deposition equipment. The second molybdenum support device is used to support the silicon-based dielectric layer to expose the second surface of the silicon-based dielectric layer, the inner wall of the pin hole and the side surface. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the third process parameters are controlled to perform a third-stage deposition on the second surface of the silicon-based dielectric layer, the inner wall of the pin hole, and the side surface, to obtain the electrostatic chuck with the diamond protective film. The diamond protective film includes the initial diamond film, the first diamond film, and the second diamond film, wherein the second diamond film is the diamond film formed by the third-stage deposition. The third process parameters are set as follows: the gas pressure of the microwave plasma chemical vapor deposition chamber is 10kPa-20kPa, the microwave power is 30kW-35kW, the microwave frequency is 915MHz, and the temperature range of the silicon-based dielectric layer is 850℃-900℃. The deposition time for the third stage is 3-5 hours, the flow rate of hydrogen is 2000-2300 sccm, the flow rate of methane is 32-35 sccm, and the flow rate of oxygen is 0.5-0.8 sccm.

[0016] Optionally, it also includes: after completing the third stage deposition, annealing in a hydrogen atmosphere, then cooling the electrostatic chuck with the diamond protective film to room temperature, removing it for cleaning, and then storing it.

[0017] Secondly, this application provides a diamond electrostatic chuck, including a diamond electrostatic chuck prepared by any of the diamond electrostatic chuck preparation methods described above.

[0018] As can be seen from the above, the diamond electrostatic chuck and its preparation method provided in this application pre-treat the silicon-based electrostatic chuck to construct a uniformly distributed seed layer on the surface of its silicon-based dielectric layer, providing an ideal nucleation interface for subsequent diamond deposition; a first-stage deposition is performed based on the silicon-based dielectric layer to form an initial diamond film on the first surface of the silicon-based dielectric layer and the inner wall of the pin hole, obtaining an initial film with suitable roughness and uniform thickness; a second-stage deposition is performed on the surface of the initial diamond film, the inner wall of the pin hole of the silicon-based dielectric layer, and the side surface of the silicon-based dielectric layer to form a first diamond film, further depositing and covering the electrostatic chuck sides and pin holes not covered by the initial diamond film; the silicon... The base dielectric layer is flipped, and a third-stage deposition is performed on the second surface based on the silicon-based dielectric layer. The exposed positions at the bottom of the pin holes (i.e., the pin holes on the second surface) are deposited to obtain an electrostatic chuck with a complete diamond protective film. The diamond protective film includes an initial diamond film, a first diamond film, and a second diamond film. The second diamond film is the diamond film formed in the third-stage deposition. By using a 915MHz microwave plasma chemical vapor deposition equipment and combining deposition process parameters, the electrostatic chuck achieves full diamond coverage, ensuring overall insulation and thermal conductivity. This solves the problems of large-area uniform deposition, three-dimensional structure coverage, and the balance between surface roughness and electrical / thermal performance.

[0019] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing embodiments of this application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the first process for preparing a diamond electrostatic chuck according to an embodiment of this application.

[0021] Figure 2 This is a schematic diagram of a second process for preparing a diamond electrostatic chuck provided in an embodiment of this application.

[0022] Figure 3 This is a schematic diagram of the structure of the first molybdenum support device provided in an embodiment of this application.

[0023] Figure 4 A schematic diagram showing the position of the silicon-based dielectric layer on the first molybdenum support device, as provided in an embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the structure of the second molybdenum support device provided in an embodiment of this application.

[0025] Figure 6 A schematic diagram showing the position of the silicon-based dielectric layer on the second molybdenum support device, as provided in the embodiments of this application.

[0026] Figure 7 This is a macroscopic surface diagram of the diamond electrostatic chuck provided in an embodiment of this application.

[0027] Figure 8 A schematic diagram of the surface morphology of a diamond electrostatic chuck provided in an embodiment of this application.

[0028] Figure 9 This is a schematic diagram of the cross-sectional morphology of the diamond electrostatic chuck provided in the embodiments of this application.

[0029] Figure 10 This is a schematic diagram illustrating the effect of Raman analysis provided in an embodiment of this application.

[0030] Labeling explanation: 100, silicon-based dielectric layer; 101, pin hole; 200, first molybdenum support device; 300, second molybdenum support device. Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0032] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] In semiconductor manufacturing processes, existing electrostatic chucks mostly use alumina or aluminum nitride as insulating layers, which suffers from limited thermal conductivity, insufficient resistance to plasma corrosion, and difficulties in balancing surface, dielectric, and thermal properties. Diamond films are considered an ideal alternative due to their ultra-high thermal conductivity, excellent insulation, and corrosion resistance. However, they face three major challenges in large-size (8-inch to 12-inch) applications: difficulty in uniform deposition over large areas, poor coverage of complex three-dimensional structures (such as pin holes), and difficulty in balancing surface roughness and electrical / thermal properties. If these problems are not solved, the performance and reliability of electrostatic chucks will fail to meet the requirements of advanced semiconductor manufacturing processes, thereby affecting wafer production efficiency and yield.

[0034] Reference Appendix Figures 1-10 This application provides a method for preparing a diamond electrostatic chuck, comprising: Step S1: Pre-process the silicon-based dielectric layer 100 of the electrostatic chuck to obtain the pre-processed silicon-based dielectric layer 100, wherein the silicon-based dielectric layer 100 is provided with a pin hole 101 that penetrates the silicon-based dielectric layer 100. Step S2: A first-stage deposition is performed based on the pretreated silicon-based dielectric layer 100 to form an initial diamond film on the first surface of the silicon-based dielectric layer 100 and the inner wall of the pin hole 101. Step S3: A second-stage deposition is performed on the surface of the initial diamond film, inside the pinhole 101 of the silicon-based dielectric layer 100, and on the side of the silicon-based dielectric layer 100 to form the first diamond film. Step S4: The silicon-based dielectric layer 100 is flipped to perform a third-stage deposition on the second surface of the silicon-based dielectric layer 100 to obtain the electrostatic chuck with a diamond protective film. The diamond protective film includes an initial diamond film, a first diamond film, and a second diamond film. The second diamond film is the diamond film formed in the third-stage deposition.

[0035] In this application, the first surface and the second surface are two opposing surfaces, and the side surface is the side surface between the first surface and the second surface. For example, the first surface can be the upper surface, then the corresponding second surface is the lower surface; or, the first surface can be the top surface, then the corresponding second surface is the bottom surface. This application does not impose specific limitations on this. The pin holes 101 of the silicon-based dielectric layer 100 penetrate through the first surface and the second surface. The purpose of this application is to uniformly deposit a diamond protective film over a large area on the dielectric layer of a large-size electrostatic chuck. To better deposit diamond protection, the dielectric layer of the electrostatic chuck uses a silicon substrate, namely the silicon-based dielectric layer 100 of this application.

[0036] The above technical solution is illustrated by a specific example below: First, a silicon-based dielectric layer 100 is obtained from an 8-inch to 12-inch electrostatic chuck. This silicon-based dielectric layer 100 refers to a dielectric layer using silicon as a substrate. The silicon-based dielectric layer 100 has pin holes 101 that penetrate through it. The silicon-based dielectric layer 100 is then subjected to standard RCA cleaning to remove organic matter, metals, and particulate contaminants, resulting in the cleaned target silicon-based dielectric layer 100. Subsequently, using a specially made dense wool felt, nanodiamond powder (particle size W7.0, where the upper limit of W7.0 is approximately 10 μm, the lower limit is approximately 3 μm to 5 μm, the median is approximately 7.0 μm, and the actual D50 (median diameter) is usually between 5 μm and 7 μm) is evenly applied and wiped on the first surface, sides, and inner walls of all holes (e.g., pin holes 101) of the target silicon-based dielectric layer to form a seed layer on the target silicon-based dielectric layer, thereby obtaining the pretreated silicon-based dielectric layer 100. This pretreatment step ensures the cleanliness of the electrostatic chuck surface and provides seed nucleation sites for the subsequent uniform growth of diamond films.

[0037] Next, the pretreated silicon-based dielectric layer 100 is placed on a custom-designed, encapsulated first molybdenum support device 200, as follows: Figure 3 As shown, the first molybdenum support device 200 completely encloses and adheres to the side surface and second surface of the silicon-based dielectric layer 100, exposing only the first surface of the silicon-based dielectric layer 100 and the pin hole 101, as shown. Figure 4As shown, this is to ensure that the reactive gas and plasma act more uniformly on the flat first surface and the inner wall of the pin hole 101 during the first-stage deposition process, avoiding interference from the side edges on the airflow and electric field, so as to form an initial diamond film with better crystal quality, thickness and more uniform diamond grain size on the first surface and the inner wall of the pin hole 101. Subsequently, the first molybdenum support device 200 with the silicon-based dielectric layer 100 assembled is placed in a 915MHz microwave plasma chemical vapor deposition apparatus (i.e., MPCVD chamber). Compared to the traditional 2.45GHz, the 915MHz microwave frequency can excite larger and more uniform plasma spheres, which is the fundamental guarantee for achieving thickness and mass uniformity within the 8-12 inch range. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, high-purity hydrogen, methane, and oxygen are introduced, and the first deposition process parameters are controlled (e.g., gas pressure range of 10kPa-20kPa, microwave power range of 30kW-35kW, silicon-based dielectric layer 100 temperature range of 850℃-900℃; hydrogen flow rate range of 2000sccm-2300sccm, methane flow rate range of 32sccm-35sccm, and oxygen flow rate range of 0.5sccm). The first stage of deposition, with a deposition time ranging from 16 to 20 hours, is performed to form a high-quality intrinsic polycrystalline diamond film with uniform thickness, controllable grain size, and controllable surface roughness on the first surface of the silicon-based dielectric layer 100. (Intrinsic: specifically refers to the electrical, optical, and chemical properties of a material determined by its pure crystal structure itself, rather than being dominated by external impurities or defects). The high-quality intrinsic polycrystalline diamond film is used as the initial diamond film. The main function of the initial diamond film is to form a uniform "underlayment" on the upper surface in advance, avoiding the edge effect during subsequent side deposition from interfering with the quality of the first surface. The initial diamond film formed by the above process has a thickness ranging from 18 μm to 20 μm (thickness deviation < ±5%), a grain size ranging from 1 μm to 5 μm, and a surface roughness ranging from 0.2 μm to 0.5 μm.

[0038] After the first stage of deposition is completed, the gas and microwave are turned off, and the sample is cooled and removed. At this point, the sample is replaced with a flat-plate second molybdenum support device 300, as shown below. Figure 5 As shown, the silicon-based dielectric layer 100 is placed on the second molybdenum support device 300, so that the first surface, the pin hole 101, and the entire side surface of the silicon-based dielectric layer 100 are exposed, as shown. Figure 6As shown. The second molybdenum support device 300, which supports the silicon-based dielectric layer 100, is placed back into the 915MHz microwave plasma chemical vapor deposition equipment. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the second deposition process parameters are controlled (e.g., hydrogen flow rate range of 2000 sccm-2300 sccm, methane flow rate range of 32 sccm-35 sccm, oxygen flow rate range of 0.5 sccm-0.8 sccm, gas pressure range of 10 kPa-20 kPa, microwave power range of 30 kW-35 kW, silicon-based dielectric layer 100 temperature range of 850℃-900℃) to perform the second stage deposition, with a deposition time range of 3 hours-5 hours, to form a first diamond film on the surface of the initial diamond film, the inner wall of the pin hole 101, and the side of the silicon-based dielectric layer 100. This step effectively covers the sides of the silicon-based dielectric layer 100 and the inner wall of the pin hole 101, depositing a diamond film on the sides of the silicon-based dielectric layer 100 and the inner wall of the pin hole 101, achieving insulation protection for the sides and the pin hole, while further thickening the film on the first surface. This is because during the second stage deposition, a uniform "base" layer (i.e., the initial diamond film) has already been formed on the first surface and the inner wall of the pin hole 101, while the sides grow from the exposed silicon substrate. Although the growth rates of the two are still different, this method can avoid the overgrowth or abnormal protrusion that may occur on the sides due to the large exposed area and strong edge effect in the "one-step method" (i.e., deposition completed in one step). Therefore, this application uses a step-by-step strategy, in conjunction with the first molybdenum support device 200 and the second molybdenum support device 300, to make the thickness transition between the first surface and the sides smoother and the overall uniformity better.

[0039] Subsequently, the silicon-based dielectric layer 100 with the first diamond film is removed from the second molybdenum support device 300, and after being rotated 180 degrees, it is placed back onto the flat second molybdenum support device 300, as follows. Figure 2 As shown, the second surface is positioned upwards, exposing the second surface, pin hole 101, and side surface. The second molybdenum support device 300, with the silicon-based dielectric layer 100 placed, is then placed back into a 915MHz microwave plasma chemical vapor deposition apparatus (i.e., Figure 2In the MPCVD chamber shown, after evacuating the chamber of a 915MHz microwave plasma chemical vapor deposition (MPCVD) apparatus, hydrogen, methane, and oxygen are introduced. Third process parameters are controlled (e.g., hydrogen flow rate range of 2000-2300 sccm, methane flow rate range of 32-35 sccm, oxygen flow rate range of 0.5-0.8 sccm, gas pressure range of 10-20 kPa, microwave power range of 30-35 kW, and silicon-based dielectric layer 100 temperature range of 850°C-900°C) to perform the third-stage deposition for 3-5 hours. This forms a second diamond film on the second surface of the silicon-based dielectric layer 100, the inner wall of the pin hole 101, and its sides, ultimately resulting in an electrostatic chuck with a complete diamond protective film. The diamond protective film includes an initial diamond film, a first diamond film, and a second diamond film, with the second diamond film being the diamond film formed during the third-stage deposition. This flip-and-redeposition method ensures that diamond films are uniformly formed from both ends of the pin holes 101 on the silicon-based dielectric layer 100, and also ensures that all locations on the silicon-based dielectric layer 100 requiring dielectric layer coverage obtain the required diamond film, achieving comprehensive and uniform diamond film coverage on large-size (e.g., 8-inch-12-inch) electrostatic chucks. The macroscopic surface morphology of the resulting electrostatic chuck is shown in the figure. Figure 7 As shown, the surface morphology of the electrostatic chuck was then measured using a scanning electron microscope, as shown. Figure 8 As shown, scanning electron microscopy (SEM) analysis revealed an average grain size range of approximately 1 μm-2 μm, which is in line with design expectations. The cross-sectional morphology of the electrostatic chuck was also analyzed using SEM, as shown below. Figure 9 As described above, scanning electron microscopy analysis revealed that the average thickness of the diamond film was 8 μm, exhibiting excellent uniformity. Raman spectroscopy analysis of the electrostatic chuck further confirmed this. Figure 10 As shown, from Figure 10 The results show a sharp diamond characteristic peak at 1332 cm⁻¹, and no obvious amorphous carbon or graphite peak (-1550 cm⁻¹), indicating that the diamond film is a high-purity sp₂. 3 The diamond phase, with its high-purity sp³ structure, endows the thin film with excellent insulation properties, thus meeting the application requirements of electrostatic chucks for high resistivity dielectric layers.

[0040] Finally, after completing the third stage of deposition, the sample was annealed in a pure hydrogen atmosphere, then slowly cooled to room temperature, removed, cleaned, and stored. Annealing helps optimize the crystal structure and stress of the diamond protective film, further improving the performance and stability of the diamond electrostatic chuck.

[0041] The aforementioned preparation method utilizes a 915MHz microwave plasma chemical vapor deposition (MPCVD) system, combined with a staged, multi-angle deposition process strategy, to innovatively apply diamond coatings to the protective coating of electrostatic chucks. This systematically solves the problems of large-area uniform deposition, the inability to effectively cover diamond films with complex three-dimensional structures, and the difficulty in achieving the required surface roughness of diamond films for electrostatic chuck use in the preparation of large-size diamond electrostatic chucks. Compared to the traditional 2.45GHz MPCVD method, which is limited by the size of the plasma sphere and thus cannot achieve uniform thickness, grain size, and crystal quality on large-size substrates, this application uses a 915MHz microwave plasma chemical vapor deposition system, combined with a customized molybdenum support device and a staged deposition process, to achieve uniform deposition of diamond films on 8-inch to 12-inch electrostatic chucks. Furthermore, by setting up a first molybdenum support device 200 to encapsulate the silicon-based dielectric layer 100, the increased electrostatic discharge risk at the aperture edges due to electric field concentration and film accumulation, as seen in traditional techniques, is avoided. Meanwhile, by precisely controlling the deposition process parameters, the grain size, orientation, and surface morphology of the diamond film can be adjusted. Under the premise of ensuring excellent insulation and high thermal conductivity, an "optimal" surface roughness range (0.2μm-0.8μm) can be achieved, which meets the comprehensive requirements of the electrostatic chuck for wafer adsorption force and plasma local discharge control.

[0042] In some embodiments, the silicon-based dielectric layer 100 of the electrostatic chuck is pretreated to obtain a pretreated silicon-based dielectric layer 100, including: obtaining the silicon-based dielectric layer 100 of the electrostatic chuck; cleaning the silicon-based dielectric layer 100 to remove contaminants from the silicon-based dielectric layer 100 to obtain a cleaned target silicon-based dielectric layer; and wiping the first surface, second surface, side surface, and pin hole 101 of the target silicon-based dielectric layer with diamond powder to form a seed layer on the target silicon-based dielectric layer to obtain the pretreated silicon-based dielectric layer 100.

[0043] The seed layer is prepared by physically wiping diamond particles into the surface of the silicon-based dielectric layer 100 and the inner wall of the pin holes 101. By selecting diamond powder within a specific particle size range (e.g., 5μm–7μm) and using wool felt to uniformly dry-brush the surface of the silicon-based dielectric layer 100 and the pin holes, the density and distribution of the initial nucleation sites can be controlled. These nucleation sites are the starting point for subsequent diamond grain growth. By controlling the seed crystal size, the microstructure of the film growth can be pre-defined. Once the deposition process begins, diamond grains grow upwards from these uniformly distributed nucleation sites. By controlling the growth parameters, grain merging and competitive growth occur. Finally, by controlling the total film thickness and grain size, a specific range of surface roughness is achieved, ranging from 0.2μm to 0.8μm, which significantly enhances the electrostatic chuck's adsorption performance on the wafer.

[0044] In a specific implementation scenario, diamond powder with a particle size in the range of 5μm to 7μm can be selected. A wool felt is used to evenly apply the diamond powder, and then, with uniform pressure and speed, all surfaces of the silicon-based dielectric layer 100, including the first surface, second surface, side surfaces, and the inner wall of the pin holes 101, are thoroughly wiped to ensure that the diamond powder is uniformly adsorbed onto the silicon-based dielectric layer 100, forming a seed layer with uniform density. The particle size and distribution density of the seed crystal directly affect the grain size and surface roughness of the final diamond film. By precisely selecting the specifications of the seed crystal powder, the surface roughness of the final silicon-based dielectric layer 100 can be initially and effectively controlled under relatively fixed deposition process parameters, laying the foundation for achieving the optimal roughness range of 0.2μm-0.8μm.

[0045] In some embodiments, a first-stage deposition is performed based on the pretreated silicon-based dielectric layer 100 to form an initial diamond film on the first surface of the silicon-based dielectric layer 100 and the inner wall of the pin hole 101. This includes placing the pretreated silicon-based dielectric layer 100 on a pre-set first molybdenum support device 200 and placing the first molybdenum support device 200 in a 915MHz microwave plasma chemical vapor deposition apparatus. The 915MHz microwave plasma chemical vapor deposition apparatus can excite larger volume and more uniform plasma spheres, which is essential for achieving an 8-inch-1 The fundamental guarantee of thickness and quality uniformity within a 2-inch range is then achieved by using a first molybdenum support device 200 to wrap and adhere the side and second surfaces of the silicon-based dielectric layer 100 to expose the first surface of the silicon-based dielectric layer 100 and the pin hole 101. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the first deposition process parameters are controlled to perform the first stage deposition of the silicon-based dielectric layer 100 to form an initial diamond film on the first surface of the silicon-based dielectric layer 100 and the inner wall of the pin hole 101.

[0046] During deposition, the first molybdenum support device 200 tightly wraps around the sides and second surface of the silicon-based dielectric layer 100, transforming the originally complex three-dimensional structure into a single exposed plane. This design physically isolates the interaction between the plasma and the sides and edges of the silicon-based dielectric layer 100. During plasma deposition, electric field concentration easily occurs at the edges of the silicon-based dielectric layer 100, leading to an abnormally high plasma density, which in turn causes overgrowth in local areas, forming protrusions or tips. By using the first molybdenum support device 200, this application artificially creates a near-ideal "quasi-planar" deposition environment, allowing the plasma and active groups containing carbon sources to act more uniformly on the first surface of the silicon-based dielectric layer 100, thereby ensuring the high uniformity of the initial diamond film in terms of thickness, grain size, and crystal quality.

[0047] In constructing the deposition environment, the 915MHz microwave plasma chemical vapor deposition (PCCVD) equipment can excite larger and more uniform plasma spheres, significantly improving the uniformity of thickness and mass within a large size range (8 inches to 12 inches). Therefore, in this application, after placing the first molybdenum support device 200 containing the silicon-based dielectric layer 100 into the 915MHz PCCVD equipment, the background gas in the chamber of the 915MHz PCCVD equipment is first evacuated to a preset vacuum level using a vacuum pump group to eliminate the influence of impurity gases on the film quality. Subsequently, the reaction gas is introduced according to a precise flow ratio. Among them, high-purity hydrogen is the main carrier gas and reaction gas. Under the excitation of microwave energy, hydrogen molecules decompose into highly reactive hydrogen atoms. On the one hand, hydrogen atoms can effectively etch away non-diamond phases such as graphite and amorphous carbon that may form during the deposition process, playing a purification role; on the other hand, they can saturate the dangling bonds on the diamond growth surface, providing conditions for the correct bonding of carbon-based active groups. Methane, as the primary carbon source gas, undergoes molecular cracking in plasma to produce active groups such as methyl groups, which are the "building blocks" of the diamond lattice. Furthermore, the introduction of trace amounts of oxygen can further promote the removal of non-diamond phases, optimize the plasma chemical environment, and thus improve the crystallinity of the diamond film. Through precise control of the first deposition process parameters, the deposition process can be finely controlled, ultimately growing an initial diamond film of predetermined thickness and quality on the first surface of the silicon-based dielectric layer 100 and the pinholes 101.

[0048] In some embodiments, the first deposition process parameters are set as follows: the gas pressure range of the microwave plasma chemical vapor deposition chamber is 10 kPa-20 kPa, the microwave power range is 30 kW-35 kW, the temperature range of the silicon-based dielectric layer 100 is 850°C-900°C, the hydrogen flow rate range is 2000 sccm-2300 sccm, the methane flow rate range is 32 sccm-35 sccm, and the oxygen flow rate range is 0.5 sccm-0.8 sccm.

[0049] During the deposition process, a 915MHz microwave plasma chemical vapor deposition (PVDC) system is used. The 915MHz frequency corresponds to a longer microwave wavelength than the commonly used 2.45GHz. This increased wavelength means that a larger plasma region can be excited and formed within the resonant cavity. Since the physical size of the plasma sphere directly determines the effective deposition area, a larger plasma cloud can completely cover the chuck surface with diameters ranging from 8 inches to 12 inches or even larger. This helps to eliminate the thickness unevenness and crystal quality differences between the center and edges that are common problems in large-area deposition due to differences in plasma density.

[0050] In some embodiments, a second-stage deposition is performed on the surface of the initial diamond film, the inner wall of the pin hole 101, and the side surface of the silicon-based dielectric layer 100 to form a first diamond film. This includes: placing the silicon-based dielectric layer 100 with the initial diamond film on a pre-set second molybdenum support device 300, and placing the second molybdenum support device 300 in a 915MHz microwave plasma chemical vapor deposition apparatus. The second molybdenum support device 300 is used to support the silicon-based dielectric layer 100 to expose the first surface, pin hole 101, and side surface of the silicon-based dielectric layer 100; after evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition apparatus, hydrogen, methane, and oxygen are introduced, and the second deposition process parameters are controlled to perform a second-stage deposition on the surface of the initial diamond film, the inner wall of the pin hole 101, and the side surface of the silicon-based dielectric layer 100 to form a first diamond film on the first surface, the inner wall of the pin hole 101, and the side surface of the silicon-based dielectric layer 100.

[0051] After completing the first stage of base layer deposition, the process flow proceeds to the second stage of deposition. The core task of this second stage is to deposit a diamond protective layer on the sides and pin holes 101 of the silicon-based dielectric layer 100, and to appropriately thicken the thin film on the first surface. For this, the device supporting the silicon-based dielectric layer 100 needs to be replaced. Unlike the encapsulated first molybdenum support device 200 used in the first stage deposition, the second molybdenum support device 300 used in the second stage deposition is a simpler flat plate base. When the silicon-based dielectric layer 100, after completing the first stage deposition, is placed on this flat second molybdenum support device 300, the first surface covering the initial diamond film, the exposed silicon sides, and the pin holes 101 will all be fully exposed to the deposition environment. This tooling change is a crucial step in realizing the regional deposition strategy. In this way, plasma and active groups can now simultaneously act on the first surface, the inner wall, and the sides of the pin holes 101 of the silicon-based dielectric layer 100. Since the first surface and the pin hole 101 already have a uniform "base" layer (i.e. the initial diamond film), while the side is the area where new growth begins, this step-by-step deposition method can better control the film transition at the junction of the top and side compared to the one-step method, making it smoother and more continuous, avoiding abnormal protrusions or film stress concentration caused by edge effects, thus achieving a coating effect with better overall uniformity.

[0052] In controlling the deposition process, the second stage also requires a high vacuum environment with a mixture of hydrogen, methane, and oxygen introduced. By controlling the second deposition process parameters, diamond films are grown simultaneously on the first surface, the pinhole 101, and the sides. The goal of this stage is not to achieve an extremely thick film, but rather to form a protective film with sufficient insulation and corrosion resistance on the sides and the inner wall of the pinhole 101 within a reasonable time, while simultaneously reinforcing the initial diamond film on the first surface. Ultimately, a continuous and complete diamond film, namely the first diamond film, is formed on the first surface of the silicon-based dielectric layer 100, the inner wall of the pinhole 101, and the sides.

[0053] In some embodiments, the second deposition process parameters are set as follows: the chamber pressure is 10 kPa-20 kPa, the microwave power is 30 kW-35 kW, the temperature range of the silicon-based dielectric layer 100 is 850°C-900°C, the hydrogen flow rate is 2000 sccm-2300 sccm, the methane flow rate is 32 sccm-35 sccm, and the oxygen flow rate is 0.5 sccm-0.8 sccm.

[0054] Specifically, the process parameters for the second stage are essentially the same as those for the first stage. This consistency ensures that the diamond films grown at different stages have similar microstructures and physical properties, thereby guaranteeing the continuity and consistency of the performance of the entire diamond dielectric layer. The use of a 915MHz microwave plasma chemical vapor deposition (MPCVD) system is crucial for maintaining the uniformity of the large-area plasma, which is particularly important for simultaneously covering the first surface and the side surfaces, which have different orientations. The same gas pressure, power, temperature, and gas ratio ensure a stable diamond growth environment, allowing for continued epitaxial growth on the already formed initial diamond film, while also achieving high-quality nucleation and growth on the exposed silicon substrate side surfaces. By maintaining these optimized process parameters, a dense diamond protective film can be effectively formed on the side surface of the silicon substrate dielectric layer 100 during the second-stage deposition, further increasing the thickness of the initial diamond film on the first surface.

[0055] In some implementations, the deposition time for the first stage of deposition ranges from 16 to 20 hours, and the deposition time for the second stage of deposition ranges from 3 to 5 hours.

[0056] The first stage, as a crucial step in constructing the base layer, requires a relatively long deposition time, such as 20 hours, to ensure the formation of a sufficiently thick initial diamond film on the first surface of the chuck, for example, reaching 18μm-20μm, with a grain size ranging from 1μm to 5μm and a surface roughness ranging from 0.2μm to 0.5μm. In contrast, the main task of the second stage is to cover the sides and the inside of the pin holes 101 and reinforce the first surface; therefore, the deposition time is relatively short, for example, 3 hours. This time is sufficient to grow a protective layer several micrometers thick on the sides and inside the pin holes 101, providing effective insulation and corrosion protection for the sides and the inner walls of the silicon-based dielectric layer 100. By precisely controlling the deposition time of different stages, differentiated and refined control of the film thickness in different regions is achieved.

[0057] In some embodiments, the silicon-based dielectric layer 100 is flipped to perform a third-stage deposition on the second surface of the silicon-based dielectric layer 100 to obtain an electrostatic chuck with a diamond protective film. The diamond protective film includes an initial diamond film, a first diamond film, and a second diamond film. The second diamond film is the diamond film formed during the third-stage deposition. The process includes: flipping the silicon-based dielectric layer 100 with the first diamond film and placing it on a pre-set second molybdenum support device 300; and placing the second molybdenum support device 300 in a 915MHz microwave plasma chemical vapor deposition apparatus. The apparatus 300 is used to support the silicon-based dielectric layer 100 to expose the second surface, pin hole 101, and side surface of the silicon-based dielectric layer 100. After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the third process parameters are controlled to perform a third-stage deposition on the second surface, inner wall, and side surface of the silicon-based dielectric layer 100, resulting in an electrostatic chuck with a diamond protective film. The diamond protective film includes an initial diamond film, a first diamond film, and a second diamond film, wherein the second diamond film is the diamond film formed in the third-stage deposition.

[0058] The third-stage deposition is a crucial step in addressing the challenge of exposed areas at the bottom of the borehole. Its core operation involves removing the silicon-based dielectric layer 100, already coated with the first surface, pin holes 101, and sidewalls, from the 915MHz microwave plasma chemical vapor deposition (MPCVD) equipment and physically flipping it 180 degrees. This flips the second surface, which was originally facing downwards and adhering to the second molybdenum support 300, so that it faces upwards, exposing the second surface and pin holes 101. Then, the flipped silicon-based dielectric layer 100 is placed back onto the flat second molybdenum support 300 and fed into the 915MHz MPCVD equipment. At this point, the second surface of the silicon-based dielectric layer 100, as well as the previously coated sidewalls, are exposed to the deposition environment. In the first two stages, plasma can only deposit from one end of the borehole opening, resulting in a thicker film near the opening and a thinner film deeper into the borehole, sometimes failing to form effective coverage at the bottom and lower part of the sidewalls. This leaves weak points in insulation and corrosion protection. By flipping the chuck, plasma can be deposited from the other end of the hole, i.e., the opening direction of the second surface, to specifically reinforce areas that were previously insufficiently covered. This growth method from both ends to the middle enables the internal area of ​​the pin hole 101 to be completely covered by a diamond film, thereby constructing an all-around diamond protective layer.

[0059] In the third stage of deposition, precise control of the third process parameters is also required to ensure the formation of a second diamond film on the second surface, inside the pin hole 101, and on the sides of the silicon-based dielectric layer 100. Ultimately, an electrostatic chuck with a diamond protective film is obtained.

[0060] In some embodiments, the third process parameters are set as follows: the chamber pressure is 10 kPa-20 kPa, the microwave power is 30 kW-35 kW, the temperature range of the silicon-based dielectric layer 100 is 850°C-900°C, the deposition time range of the third stage deposition is 3 hours-5 hours, the hydrogen flow rate is 2000 sccm-2300 sccm, the methane flow rate is 32 sccm-35 sccm, and the oxygen flow rate is 0.5 sccm-0.8 sccm.

[0061] Similar to the second stage, the process parameters and deposition time of the third stage are consistent with the first two stages, aiming to maintain a stable chemical and physical environment conducive to high-quality diamond growth and ensure that the area within the ejector hole 101 is completely covered by diamond. The relatively short deposition time, such as 3 hours, is based on its functional positioning of "reinforcement" and "leak repair." This time is sufficient to form a functional diamond film on the second surface of the chuck and effectively cover the inner wall of the ejector hole 101. Through this unified yet step-by-step process, a comprehensive and high-quality diamond coating is finally achieved on a large-size, perforated electrostatic chuck. Since the first stage has already partially covered the orifice from the front, the deposition from the back effectively fills the film gaps at the bottom of the orifice and in the middle of the sidewalls. After 3 hours of reinforcement, full coverage of the inner wall of the orifice is achieved, thus constructing a dense and comprehensive diamond insulating protective barrier on the entire electrostatic chuck.

[0062] In some implementations, it also includes: After the third stage of deposition is completed, the annealing process is carried out in a hydrogen atmosphere. Then, the electrostatic chuck with a diamond protective film is cooled to room temperature, removed, cleaned, and then stored.

[0063] After the third stage of deposition is completed, annealing is performed in a hydrogen atmosphere. After annealing, the electrostatic chuck needs to be slowly and uniformly cooled to room temperature to avoid damage to the diamond film due to the huge thermal shock caused by the sudden temperature drop. Finally, the finished product needs to undergo a final cleaning process to remove any particles that may have been adsorbed on the surface, and then it is properly stored in a clean and dry environment, awaiting subsequent assembly and application.

[0064] This application provides a diamond electrostatic chuck, including a diamond electrostatic chuck prepared by any of the diamond electrostatic chuck preparation methods described above.

[0065] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0066] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a diamond electrostatic chuck, characterized in that, include: The silicon-based dielectric layer (100) of the electrostatic chuck is pretreated to obtain a pretreated silicon-based dielectric layer (100), wherein a pin hole (101) is provided on the silicon-based dielectric layer (100) through the silicon-based dielectric layer (100). A first-stage deposition is performed based on the pretreated silicon-based dielectric layer (100) to form an initial diamond film on the first surface of the silicon-based dielectric layer (100) and the inner wall of the pin hole (101). A second-stage deposition is performed on the surface of the initial diamond film, the inner wall of the pin hole (101), and the side of the silicon-based dielectric layer (100) to form a first diamond film; The silicon-based dielectric layer (100) is flipped to perform a third-stage deposition on the second surface of the silicon-based dielectric layer (100) to obtain the electrostatic chuck with a diamond protective film, the diamond protective film including the initial diamond film, the first diamond film and the second diamond film, the second diamond film being the diamond film formed in the third-stage deposition. The first-stage deposition based on the pretreated silicon-based dielectric layer (100) to form an initial diamond film on the first surface of the silicon-based dielectric layer (100) and the inner wall of the pin hole (101) includes: The pretreated silicon-based dielectric layer (100) is placed on a pre-set first molybdenum support device (200), and the first molybdenum support device (200) is placed in a 915MHz microwave plasma chemical vapor deposition device. The first molybdenum support device (200) is used to wrap and fit the side and second surface of the silicon-based dielectric layer (100) to expose the first surface of the silicon-based dielectric layer (100) and the inner wall of the pin hole (101). After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane and oxygen are introduced, and the first deposition process parameters are controlled to perform the first stage deposition of the silicon-based dielectric layer (100) to form the initial diamond film on the first surface of the silicon-based dielectric layer (100) and the inner wall of the pin hole (101). The process of performing a second-stage deposition on the surface of the initial diamond film, the inner wall of the pin hole (101), and the side of the silicon-based dielectric layer (100) to form a first diamond film includes: The silicon-based dielectric layer (100) having the initial diamond film is placed on a pre-set second molybdenum support device (300), and the second molybdenum support device (300) is placed in a 915MHz microwave plasma chemical vapor deposition apparatus. The second molybdenum support device (300) is used to support the silicon-based dielectric layer (100) to expose the first surface of the silicon-based dielectric layer (100), the inner wall of the pin hole (101) and the side surface of the silicon-based dielectric layer (100). After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the second deposition process parameters are controlled to perform a second stage deposition on the surface of the initial diamond film, inside the pin hole (101) of the silicon-based dielectric layer (100), and on the side of the silicon-based dielectric layer (100) to form the first diamond film on the first surface of the silicon-based dielectric layer (100), the inner wall of the pin hole (101), and the side of the silicon-based dielectric layer (100).

2. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, The pretreatment of the silicon-based dielectric layer (100) of the electrostatic chuck to obtain the pretreated silicon-based dielectric layer (100) includes: Obtain the silicon-based dielectric layer (100) of the electrostatic chuck. The silicon-based dielectric layer (100) is cleaned to remove contaminants from the silicon-based dielectric layer (100) to obtain the cleaned target silicon-based dielectric layer; Diamond powder is used to wipe the first surface, the second surface, the side surface and the pin hole (101) of the target silicon-based dielectric layer to form a seed layer on the target silicon-based dielectric layer, so as to obtain the pretreated silicon-based dielectric layer (100).

3. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, The first deposition process parameters are set as follows: the gas pressure range of the chamber is 10kPa-20kPa, the microwave power range is 30kW-35kW, and the temperature range of the silicon-based dielectric layer (100) is 850℃-900℃. The flow rate of hydrogen is in the range of 2000 sccm-2300 sccm, the flow rate of methane is in the range of 32 sccm-35 sccm, and the flow rate of oxygen is in the range of 0.5 sccm-0.8 sccm.

4. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, The second deposition process parameters are set as follows: the gas pressure in the chamber is 10kPa-20kPa, the microwave power is 30kW-35kW, and the temperature range of the silicon-based dielectric layer (100) is 850℃-900℃. The flow rate of hydrogen is 2000 sccm-2300 sccm, the flow rate of methane is 32 sccm-35 sccm, and the flow rate of oxygen is 0.5 sccm-0.8 sccm.

5. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, The deposition time range for the first stage of deposition is 16-20 hours, and the deposition time range for the second stage of deposition is 3-5 hours.

6. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, The silicon-based dielectric layer (100) is flipped to perform a third-stage deposition on the second surface of the silicon-based dielectric layer (100) to obtain the electrostatic chuck with a diamond protective film. The diamond protective film includes the initial diamond film, the first diamond film, and the second diamond film. The second diamond film is the diamond film formed in the third-stage deposition and includes: The silicon-based dielectric layer (100) with the first diamond film is flipped over and placed on a preset second molybdenum support device (300). The second molybdenum support device (300) is placed in a 915MHz microwave plasma chemical vapor deposition device. The second molybdenum support device (300) is used to support the silicon-based dielectric layer (100) to expose the second surface of the silicon-based dielectric layer (100), the pin hole (101) and the side surface of the silicon-based dielectric layer (100). After evacuating the chamber of the 915MHz microwave plasma chemical vapor deposition equipment, hydrogen, methane, and oxygen are introduced, and the third process parameters are controlled to perform a third-stage deposition on the second surface of the silicon-based dielectric layer (100), the inner wall of the pin hole (101), and the side surface of the silicon-based dielectric layer (100) to obtain the electrostatic chuck with the diamond protective film. The diamond protective film includes the initial diamond film, the first diamond film, and the second diamond film, wherein the second diamond film is the diamond film formed by the third-stage deposition. The third process parameters are set as follows: the air pressure in the chamber is 10kPa-20kPa, the microwave power is 30kW-35kW, and the temperature range of the silicon-based dielectric layer (100) is 850℃-900℃. The deposition time for the third stage is 3-5 hours, the flow rate of hydrogen is 2000-2300 sccm, the flow rate of methane is 32-35 sccm, and the flow rate of oxygen is 0.5-0.8 sccm.

7. The method for preparing a diamond electrostatic chuck according to claim 1, characterized in that, Also includes: After the third stage of deposition is completed, the annealing process is carried out in a hydrogen atmosphere, and then the electrostatic chuck with the diamond protective film is cooled to room temperature. After being removed, cleaned, and then stored.

8. A diamond electrostatic chuck, characterized in that, This includes diamond electrostatic chucks prepared using the method described in any one of claims 1-7.

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