A high-efficiency deposition platform for preparing diamond thin films

Abstract

The present invention provides a high-efficiency deposition table for preparing diamond thin films, which relates to the technical field of diamond thin film preparation. The high-efficiency deposition table for preparing diamond thin films comprises a substrate table, wherein the substrate table is equipped with a spiral disc-shaped water-cooling pipe, the central port of the spiral disc-shaped water-cooling pipe extends downward to form a water inlet pipe, and is connected to the output end of a water-cooling circulation device, and the outermost port of the spiral disc-shaped water-cooling pipe extends downward to form a water outlet pipe, and is connected to the input end of the water-cooling circulation device. During the preparation process of the diamond thin film, by building a spiral disc-shaped water-cooling pipe into the substrate table, and letting water in from the center and out from the edge end, the cooling water first cools the center of the substrate, and then gradually flows to the surrounding areas along the spiral disc-shaped water-cooling pipe, thereby achieving the effect of reducing the temperature difference on the substrate surface, avoiding the problem of poor uniformity of the prepared diamond film due to uneven temperature distribution of the substrate, and improving the preparation efficiency at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of diamond film preparation, in particular to a high-efficiency deposition platform for preparing diamond films. Background Art

[0002] Diamond films have extremely high hardness and chemical stability and are widely used in electronics, optoelectronics, mechanics and other fields. Their excellent physical and chemical properties make them a hot new material. Chemical vapor deposited diamond has attracted widespread attention in various research fields due to its excellent physical and chemical properties similar to natural diamond. Among the many CVD deposition methods, microwave plasma chemical vapor deposition has become the preferred method for preparing high-quality large-area diamond films due to its unique advantages such as non-polar discharge, concentrated plasma energy and pure plasma.

[0003] However, in the process of preparing large-area diamond films using microwave plasma chemical vapor deposition, the plasma is above the substrate. Due to the characteristics of plasma energy being strong in the middle and weak at the edges, the energy in the central area of ​​the substrate is greater than that in the edge areas. This will manifest as a phenomenon of high temperature in the central area and low temperature in the edge areas on the substrate. This phenomenon will become more obvious as the microwave power increases and the device operates for a long time, ultimately resulting in poor uniformity of the prepared diamond film, making it difficult to meet the requirements of diamond films in the high-tech field, and to a certain extent limiting the engineering application of diamond films.

[0004] In order to ensure the uniformity of the diamond film, when the microwave power is constant, the deposition pressure has to be reduced so that the large-sized plasma ball covers the substrate surface more evenly and obtains better uniformity. However, the lower the deposition pressure, the lower the deposition rate, resulting in low efficiency in the preparation of the diamond film. Moreover, simply reducing the deposition pressure cannot completely solve the problem of diamond film uniformity. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a high-efficiency deposition platform for preparing diamond films, which solves the problem of uneven temperature distribution on the substrate, resulting in poor uniformity of the prepared diamond films.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a high-efficiency deposition table for preparing diamond thin films, including a substrate table, wherein the substrate table is equipped with a spiral disc-shaped water-cooling tube, the central port of the spiral disc-shaped water-cooling tube extends downward to form a water inlet pipe, and is connected to the output end of the water-cooling circulation equipment, and the outermost port of the spiral disc-shaped water-cooling tube extends downward to form a water outlet pipe, and is connected to the input end of the water-cooling circulation equipment, so that the cooling order of the cooling water on the substrate table is gradually from the center to the surrounding areas.

[0007] Preferably, the water inlet pipe and the water outlet pipe both pass through the lower end of the substrate table.

[0008] Preferably, the deposition table also includes a base, the groove at the upper end of the base is used to hold the substrate, the base is sleeved on the outside of the substrate table and rotatably connected to each other, and the upper inner wall of the base is in contact with the upper wall of the substrate table, and the lower end of the base is fixedly connected to the output end of the electric rotating table.

[0009] Preferably, the lower end of the substrate stage passes through the central through hole of the electric rotating stage.

[0010] Preferably, the upper wall of the base and the upper part of the substrate platform are both made of high thermal conductivity materials.

[0011] Preferably, the groove portion on the upper wall of the base is a thin-walled structure.

[0012] Preferably, a molybdenum metal sheet is provided on the upper wall of the substrate table.

[0013] Furthermore, the present invention provides a method for using a deposition platform for preparing a diamond thin film with high efficiency, comprising the following steps:

[0014] Step 1: When preparing a diamond film, connect the water inlet pipe to the output end of the water cooling circulation device, connect the water outlet pipe to the input end of the water cooling circulation device, start the water cooling circulation device, and let the cooling water flow from the water inlet pipe to the center of the spiral water cooling pipe, thereby first cooling the center of the substrate, and then gradually flowing to the surrounding areas along the spiral water cooling pipe. The water temperature continues to rise, thereby reducing the amount of heat that can be taken away by the cooling water, so that the heat dissipation effect from the center to the edge of the substrate is continuously reduced, and the temperature difference from the center to the edge of the substrate is reduced;

[0015] Step 2: The electric rotating table rotates to drive the base to rotate, and then drives the substrate to rotate continuously, so that the microwave radiation received by the surface of the substrate is more uniform, thereby further improving the uniformity of the substrate temperature.

[0016] Preferably, before preparing the diamond film, an ion bombardment device is used to perform ion cleaning and surface modification on the molybdenum metal sheet on the surface of the substrate to further improve the quality and adhesion of the diamond film.

[0017] The deposition temperature for preparing diamond films is 800-1000°C and the deposition pressure is 5-10 kPa.

[0018] Working principle: The substrate stage is equipped with a spiral disc-shaped water-cooling tube, with water entering from the center and exiting from the edge. The cooling water first cools the center of the substrate, and then gradually flows to the surrounding areas along the spiral disc-shaped water-cooling tube. The water temperature continues to rise, and the amount of heat that can be taken away by the cooling water continues to decrease. That is, as the cooling water flows from the center to the edge, the cooling effect gradually decreases, and the heat dissipation effect of the substrate from the center to the edge continues to decrease. The temperature at the center of the substrate is high, and the cooling effect is also good. The temperature at the edge of the substrate is low, and the cooling effect is also reduced, thereby achieving the effect of reducing the temperature difference on the substrate surface and making the substrate temperature evenly distributed.

[0019] The electric rotating table drives the base to rotate, which further drives the substrate to rotate continuously, making the microwave radiation received by the substrate surface more uniform, thereby further improving the uniformity of the substrate temperature.

[0020] The present invention provides a high-efficiency deposition platform for preparing diamond thin films. It has the following beneficial effects:

[0021] 1. The present invention embeds a spiral disc-shaped water-cooling tube in the substrate table, and water enters from the center and exits from the edge end, so that the cooling water first cools the center of the substrate, and then gradually flows to the surrounding areas along the spiral disc-shaped water-cooling tube. The water temperature continues to rise, and the heat that can be taken away by the cooling water continues to decrease. That is, in the process of the cooling water flowing from the center to the edge, the cooling effect gradually decreases, and the heat dissipation effect of the substrate from the center to the edge continues to decrease, so that the temperature at the center of the substrate is high and the cooling effect is also good, and the temperature at the edge of the substrate is low and the cooling effect is also reduced, thereby achieving the effect of reducing the temperature difference on the surface of the substrate, avoiding the problem of poor uniformity of the prepared diamond film due to uneven temperature distribution of the substrate. At the same time, since the problem of uneven temperature distribution is solved, the deposition pressure can be increased in the preparation process of the diamond film, thereby improving the preparation efficiency.

[0022] 2. The present invention drives the base to rotate by an electric rotating table, which further drives the substrate to rotate continuously, so that the microwave radiation received by the substrate surface is more uniform, thereby further improving the uniformity of the substrate temperature. At the same time, the diamond crystals are uniformly deposited on the substrate surface, avoiding the accumulation and aggregation of crystals on the substrate surface, thereby ensuring the uniformity and quality of the diamond film. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a front perspective view of the present invention;

[0024] Figure 2 It is a front cross-sectional view of the present invention;

[0025] Figure 3 Schematic diagram of the spiral disc-shaped water cooling tube in the present invention;

[0026] Figure 4It is a cross-sectional schematic diagram of the substrate stage in the present invention.

[0027] Among them, 1. base; 2. substrate; 3. electric rotating table; 4. substrate table; 5. spiral disc water cooling pipe; 6. water inlet pipe; 7. water outlet pipe. Implementation Method

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1:

[0029] Please see the attached Figure 1 -Attached Figure 4 An embodiment of the present invention provides a high-efficiency deposition table for preparing diamond thin films, including a substrate table 4. A spiral disc-shaped water-cooling tube 5 is built into the upper part of the substrate table 4. The central port of the spiral disc-shaped water-cooling tube 5 extends downward to form a water inlet pipe 6, which is connected to the output end of the water-cooling circulation device. The outermost port of the spiral disc-shaped water-cooling tube 5 extends downward to form a water outlet pipe 7, which is connected to the input end of the water-cooling circulation device, so that the cooling order of the cooling water on the substrate table 4 is gradually from the center to the surrounding area.

[0030] Under a given deposition pressure, the substrate temperature increases with the increase of microwave power. At the same time, for a given microwave power, the substrate temperature also increases with the increase of deposition pressure. As the deposition pressure and microwave power increase, the uniformity of the substrate temperature also decreases. In addition, during the specific experimental process, it was found that the size of the plasma ball is also closely related to the microwave power and deposition pressure. The general rule is that when the microwave power is constant, the higher the deposition pressure, the smaller the plasma ball; when the deposition pressure is constant, the greater the microwave power, the larger the plasma ball.

[0031] When the microwave power is constant, the lower the deposition gas pressure, the higher the substrate temperature uniformity is because the large-sized plasma ball covers the substrate surface more evenly. However, when the microwave power is constant, a higher deposition gas pressure can obtain a higher substrate temperature, thereby effectively increasing the deposition rate.

[0032] Higher microwave power can excite more groups that are beneficial to diamond film deposition, but it also makes the temperature difference on the substrate more obvious. Therefore, the deposition platform needs to be improved to improve the uniformity of substrate temperature at high power.

[0033] By building a spiral disc-shaped water-cooling tube 5 into the substrate table 4, and letting water in from the center and out from the edge end, the cooling water first cools the center of the substrate 2, and then gradually flows to the surrounding areas along the spiral disc-shaped water-cooling tube 5, the water temperature continues to rise, and the heat that can be taken away by the cooling water continues to decrease, that is, in the process of the cooling water flowing from the center to the edge, the cooling effect gradually decreases, and the heat dissipation effect of the substrate 2 from the center to the edge continues to decrease, so that the temperature of the center of the substrate 2 is high and the cooling effect is also good, the temperature of the edge of the substrate 2 is low, and the cooling effect is also reduced, thereby achieving the effect of reducing the temperature difference on the surface of the substrate 2, avoiding the problem of poor uniformity of the prepared diamond film due to uneven temperature distribution of the substrate 2, and at the same time, because the problem of uneven temperature distribution is solved, the deposition pressure can be increased in the preparation process of the diamond film, thereby improving the preparation efficiency. Example 2:

[0034] On the basis of the above embodiment, the present embodiment further improves the above embodiment to achieve the purpose of further improving the temperature uniformity of the substrate 2. The deposition table also includes a base 1. The groove at the upper end of the base 1 is used to hold the substrate 2. The base 1 is sleeved on the outside of the substrate table 4 and is rotatably connected to each other. The upper inner wall of the base 1 is in contact with the upper wall of the substrate table 4. The lower end of the base 1 is fixedly connected to the output end of the electric rotating table 3.

[0035] During the microwave chemical vapor deposition process, microwave radiation continuously acts on the surface of substrate 2, causing the surface temperature of substrate 2 to continuously increase. However, due to the limited thermal conductivity of substrate 2, the surface temperature distribution of substrate 2 is uneven, with some areas being too high and some areas being too low.

[0036] This uneven temperature distribution affects the quality and performance of diamond films. If the temperature is too high, the crystallinity of the diamond film decreases and the number of grain boundaries increases, which affects the mechanical and optical properties of the film. If the temperature is too low, the growth rate of the diamond film slows down, affecting the thickness and uniformity of the film.

[0037] Therefore, during the microwave chemical vapor deposition process, measures need to be taken to reduce the uneven distribution of substrate surface temperature to ensure the quality and performance of the diamond film. The substrate is rotated to evenly distribute the microwave radiation and improve the thermal conductivity of the substrate surface.

[0038] The electric rotating table 3 drives the base 1 to rotate, which further drives the substrate 2 to rotate continuously, making the microwave radiation received by the surface of the substrate 2 more uniform, thereby further improving the temperature uniformity of the substrate 2. At the same time, the diamond crystals are evenly deposited on the surface of the substrate 2, avoiding the accumulation and aggregation of crystals on the surface of the substrate 2, thereby ensuring the uniformity and quality of the diamond film.

[0039] The water inlet pipe 6 and the water outlet pipe 7 both pass through the lower end of the substrate stage 4 .

[0040] The lower end of the substrate stage 4 passes through the central through hole of the electric rotating stage 3.

[0041] This avoids the water inlet pipe 6 and the water outlet pipe 7 from hindering the rotation of the base.

[0042] The upper wall of the base 1 and the upper part of the substrate stage 4 are both made of high thermal conductivity materials.

[0043] Since the upper wall of the base 1 and the upper part of the substrate table 4 are both made of high thermal conductivity materials, heat can be better conducted, so that the cooling water can take away the heat more quickly, thereby improving the efficiency of heat conduction and increasing the cooling effect of the cooling water, avoiding quality problems caused by excessive temperature during the preparation of the diamond film.

[0044] The groove portion on the upper wall of the base 1 is a thin-walled structure.

[0045] The groove on the upper wall of base 1 is used to accommodate substrate 2. Its thickness affects the heat conduction distance between substrate 2 and base 1. By reducing the thickness of the groove on the upper wall of base 1, the heat conduction distance can be shortened, allowing substrate 2 to dissipate heat more quickly, thereby improving heat conduction efficiency. Furthermore, reducing the thickness of the groove on the upper wall of base 1 can increase the cooling effect of the cooling water, allowing the cooling water to dissipate heat more quickly, thereby avoiding the problem of excessive temperature causing a decrease in the quality of the diamond film.

[0046] In addition, reducing the thickness of the groove portion on the upper wall of the base 1 can also reduce the mass of the base 1, thereby reducing the thermal inertia of the entire system, allowing the system to respond to temperature changes more quickly, thereby improving the preparation efficiency and quality of the diamond film.

[0047] Therefore, by reducing the thickness of the groove portion on the upper wall of the base 1 , the heat conduction efficiency can be improved during the preparation of the diamond film, the cooling effect can be increased, and the occurrence of quality problems caused by excessive temperature can be avoided. Example 3:

[0048] Based on the above embodiment, this embodiment provides a method for using a deposition platform for efficiently preparing a diamond thin film, comprising the following steps:

[0049] Step 1: When preparing a diamond film, connect the water inlet pipe 6 to the output end of the water cooling circulation device, connect the water outlet pipe 7 to the input end of the water cooling circulation device, start the water cooling circulation device, and the cooling water reaches the center of the spiral disc-shaped water cooling pipe 5 from the water inlet pipe 6, thereby first cooling the center of the substrate 2, and then gradually flows to the surrounding areas along the spiral disc-shaped water cooling pipe 5. The water temperature continues to rise, thereby continuously reducing the heat that can be taken away by the cooling water, achieving a continuous decrease in the heat dissipation effect from the center to the edge of the substrate 2, and reducing the temperature difference from the center to the edge of the substrate 2;

[0050] Step 2: The electric rotating table 3 rotates to drive the base 1 to rotate, and then drives the substrate 2 to rotate continuously, so that the microwave radiation received by the surface of the substrate 2 is more uniform, thereby further improving the temperature uniformity of the substrate 2.

[0051] Before preparing the diamond film, an ion bombardment device is used to perform ion cleaning and surface modification on the molybdenum metal sheet on the surface of the substrate 2 to further improve the quality and adhesion of the diamond film.

[0052] An ion bombardment device uses ion beams to clean and modify the surface of an object. During the diamond film preparation process, the ion bombardment device is used to ion clean and modify the molybdenum metal flakes on the surface of substrate 2. This removes surface contamination and impurities, while improving the surface structure and properties, allowing the diamond film to better adhere to the substrate.

[0053] The ion beam from an ion bombardment device can create tiny concave and convex structures on the substrate surface, increasing surface roughness and thus improving the adhesion of the diamond film. Ion bombardment also alters the chemical properties of the substrate surface, making the growth of the diamond film more uniform and stable, thereby improving the film's quality and performance. Therefore, using an ion bombardment device to ion clean and modify the substrate surface is a very important step in the preparation of diamond films.

[0054] In order to reduce contamination and impurities during the deposition process, an ion bombardment device can be used to perform ion cleaning and surface modification on the molybdenum metal sheet on the surface of the substrate 2 to further improve the quality and adhesion of the diamond film.

[0055] The deposition temperature for preparing diamond films is 800-1000°C and the deposition pressure is 5-10 kPa.

[0056] Because the problem of uneven substrate surface temperature is solved by using a built-in spiral disk-shaped water cooling tube and an electric rotary table to drive the substrate to rotate continuously, the temperature and deposition pressure can be increased as much as possible within the temperature and pressure range to achieve the effect of efficiently preparing high-quality diamond films.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency deposition table for preparing diamond thin films, comprising a substrate table (4), characterized in that: A spiral disc-shaped water cooling pipe (5) is built into the upper part of the substrate stage (4), the central port of the spiral disc-shaped water cooling pipe (5) extends downward to form a water inlet pipe (6), which is connected to the output end of the water cooling circulation device, and the outermost port of the spiral disc-shaped water cooling pipe (5) extends downward to form a water outlet pipe (7), which is connected to the input end of the water cooling circulation device, so that the cooling water cools the substrate stage (4) from the center to the surrounding area. The deposition table further comprises a base (1), the groove at the upper end of the base (1) is used to hold the substrate (2), the base (1) is sleeved on the outside of the substrate table (4) and is rotatably connected to each other, and the inner upper wall of the base (1) is in contact with the upper wall of the substrate table (4), and the lower end of the base (1) is fixedly connected to the output end of the electric rotating table (3); The water inlet pipe (6) and the water outlet pipe (7) both pass through the lower end of the substrate table (4); The lower end of the substrate stage (4) passes through the central through hole of the electric rotating stage (3).

2. A high-efficiency deposition platform for preparing diamond thin films according to claim 1, characterized in that: The upper wall of the base (1) and the upper part of the substrate stage (4) are both made of high thermal conductivity materials.

3. A high-efficiency deposition platform for preparing diamond thin films according to claim 2, characterized in that: The groove portion on the upper wall of the base (1) is a thin-walled structure.

4. The high-efficiency deposition platform for preparing diamond thin films according to claim 1, characterized in that: The upper wall of the substrate stage (4) is provided with a molybdenum metal sheet.

5. A method for using the high-efficiency deposition platform for preparing a diamond thin film according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: When preparing a diamond film, connect the water inlet pipe (6) to the output end of the water cooling circulation equipment, connect the water outlet pipe (7) to the input end of the water cooling circulation equipment, start the water cooling circulation equipment, and let the cooling water flow from the water inlet pipe (6) to the center of the spiral disc-shaped water cooling pipe (5), thereby first cooling the center of the substrate (2), and then gradually flowing to the surrounding areas along the spiral disc-shaped water cooling pipe (5). The water temperature continues to rise, thereby reducing the amount of heat that can be taken away by the cooling water, so that the heat dissipation effect of the substrate (2) from the center to the edge is continuously reduced, and the temperature difference of the substrate (2) from the center to the edge is reduced; Step 2: The electric rotating table (3) rotates to drive the base (1) to rotate, thereby driving the substrate (2) to rotate continuously, so that the microwave radiation received by the surface of the substrate (2) is more uniform, thereby further improving the uniformity of the temperature of the substrate (2).

6. The method for using a high-efficiency deposition platform for preparing a diamond thin film according to claim 5, characterized in that: Before preparing the diamond film, an ion bombardment device is used to perform ion cleaning and surface modification on the molybdenum metal sheet on the surface of the substrate (2), thereby further improving the quality and adhesion of the diamond film.

7. The method for using a high-efficiency deposition platform for preparing a diamond thin film according to claim 5, characterized in that: The deposition temperature for preparing diamond films is 800-1000°C and the deposition pressure is 5-10 kPa.

Images