Diamond vapor deposition equipment adopting carbon dioxide as carbon source

Abstract

The invention provides diamond vapor deposition equipment adopting carbon dioxide as a carbon source, and relates to the technical field of diamond vapor deposition. Comprising a microwave system for generating microwaves; the plasma reaction cavity comprises a cavity body and a liftable substrate table; a hollow cylinder extending vertically is arranged in the middle of the cavity, the axis of the hollow cylinder directly faces the substrate table, the top of the hollow cylinder is connected to the inner side wall of the cavity through a first flat plate, a plurality of first through holes are formed in the first flat plate, and the first through holes are connected to an air outlet through a pipeline; a boss is arranged below the substrate table, and in the ascending process of the substrate table, the boss is attached to the inner wall of the hollow cylinder to form isolation; a connecting mechanism used for maintaining the height of the boss is arranged between the boss and the first flat plate. The cavity is divided into two parts, reaction gas, namely carbon dioxide, is prevented from entering the position below the substrate table, and meanwhile the limitation of the overlapping area is eliminated.

Description

Technical Field

[0001] The present application relates to the technical field of diamond vapor deposition, and in particular to a diamond vapor deposition device using carbon dioxide as a carbon source. Background Art

[0002] Currently, artificial diamonds are usually produced using microwave plasma chemical vapor deposition (MPCVD) technology to grow high-quality artificial diamonds on the surface of substrate materials.

[0003] In the context of the global response to climate change, the development of greenhouse gas capture and utilization technology has become a key path to promote green and low-carbon development. Low-carbon biosynthesis technology using one carbon greenhouse gas as raw material is a typical carbon-negative technology. It explores a new path for green synthesis of diamonds using carbon dioxide as a carbon source through microwave plasma chemical vapor deposition technology. Achieving sustainable and environmentally friendly production of diamonds will not only help reduce greenhouse gas emissions, but also achieve the recycling of resources.

[0004] At the same time, in plasma chemical vapor deposition equipment that uses carbon dioxide as a carbon source, the problem that the utilization rate of the reaction gas cannot be improved is extremely prominent. If there is a large amount of space under the substrate stage, if the reaction gas enters under the substrate stage, it cannot participate in the reaction and be discharged to the outside, which will directly lead to a large amount of greenhouse gas emissions. For example, the Chinese invention patent application with publication number CN116555735A proposes a plasma chemical vapor deposition system. During the vapor deposition process, the cavity is divided into two parts by a first baffle in the middle of the cavity and a second baffle on the top of the substrate stage to prevent the reaction gas from entering under the substrate stage. However, the system still has the following technical problems: because the first baffle and the second baffle partially overlap in the vertical direction to form isolation. On the one hand, the isolation effect is directly related to the size of the overlapping area, and the size of the overlapping area is limited by the inner diameter of the cavity, so the isolation effect is also limited; on the other hand, when the snap-fit ​​mechanism that keeps the first baffle plate and the second baffle plate in contact is working, the connecting piece slides into the anti-slip groove through the relative rotation of the first baffle plate and the second baffle plate. However, when a good isolation effect is to be maintained, there will be a large friction between the first baffle plate and the second baffle plate, making it difficult to rotate; conversely, when it is easy to rotate, the isolation effect will be unsatisfactory. Summary of the invention

[0005] The present application provides a diamond vapor deposition device using carbon dioxide as a carbon source to at least solve the above technical problems existing in the prior art.

[0006] According to a first aspect of the present application, there is provided a diamond vapor deposition apparatus using carbon dioxide as a carbon source, comprising: A microwave system for generating microwaves, wherein the microwaves enter the plasma reaction chamber to excite the carbon dioxide into a plasma ball; A plasma reaction chamber, comprising a chamber body and a liftable substrate stage; The cavity is provided with an air inlet and an air outlet, the air inlet is used to introduce carbon dioxide; a vertically extending hollow cylinder is provided in the middle of the cavity, the axis of the hollow cylinder is directly facing the substrate stage, the top of the hollow cylinder is connected to the inner wall of the cavity via a first flat plate, the first flat plate is provided with a plurality of first through holes, and the first through holes are connected to the air outlet via pipelines; A boss is arranged below the substrate stage. When the substrate stage rises, the boss is attached to the inner wall of the hollow cylinder to form isolation. A connecting mechanism for maintaining the height of the boss is arranged between the boss and the first flat plate.

[0007] According to certain embodiments of the first aspect of the present application, the microwave system includes a microwave source, a waveguide, a mode converter and a three-screw impedance adapter; the microwave source generates microwaves, the three-screw impedance adapter matches the impedance, the microwaves are transmitted along the waveguide to the mode converter, and enter the plasma reaction chamber under the action of the mode converter, and carbon dioxide is excited into a plasma ball above the substrate stage.

[0008] According to certain embodiments of the first aspect of the present application, the connection mechanism comprises: An extension portion, arranged on the side wall of the boss and extending outwards; A first connecting portion is arranged on the upper side of the extension portion, the first connecting portion comprises a first slot extending vertically, a plurality of first sliding slots extending horizontally are arranged at the same height on the side wall of the first slot, a locking tongue and a first spring are slidably arranged in each first sliding slot, the first spring provides pressure for the locking tongue toward the center of the first slot, and a first slope arranged obliquely upward is arranged at one end of the locking tongue facing the first slot; The second connecting part is arranged on the lower side of the first flat plate, and the second connecting part includes a connecting rod connected to the first flat plate, the connecting rod is opposite to the first slot, and a locking strip is fixedly provided on the lower end of the connecting rod, and a second slope slanting downward is provided on the edge of the locking strip; when the substrate stage rises, the first slope and the second slope contact, so that the locking tongue moves in a direction away from the center of the first slot, and the locking tongue moves to the upper side of the locking strip, and the locking strip forms a height limit for the locking tongue.

[0009] According to certain embodiments of the first aspect of the present application, an unlocking bar is slidably provided on the connecting rod, and a third slope inclined upward is provided on the edge of the unlocking bar; as the substrate stage continues to rise, the locking tongue moves to the upper side of the unlocking bar; as the substrate stage descends, the third slope contacts the lower side of the locking tongue, and first the unlocking bar slides downward until it fits with the locking bar, and then the third slope causes the locking tongue to move in a direction away from the center of the first slot, and the locking tongue then moves downward to the lower side of the locking bar, and the locking tongue disengages from the locking bar.

[0010] In certain embodiments according to the first aspect of the present application, a second spring is provided between the locking bar and the unlocking bar for providing an upward force to the unlocking bar.

[0011] According to certain embodiments of the first aspect of the present application, at least one of the locking bar and the unlocking bar is provided with a receiving groove, and the receiving groove is used to receive the second spring when the locking bar and the unlocking bar are in contact with each other.

[0012] In certain embodiments according to the first aspect of the present application, an adjustment mechanism is provided in the boss to adjust the raising and lowering of the substrate stage according to the height of the diamond growth.

[0013] According to certain embodiments of the first aspect of the present application, the bottom of the substrate stage is columnar, and the boss is sleeved on the outer side of the substrate stage; the adjustment mechanism includes a second slide groove and a slide table; The second chute is in the shape of a ring extending in the vertical direction, the upper half of which is completely located in the boss, and the lower half of which is an opening on the inner wall of the boss; The slide is in the shape of a ring extending in the vertical direction, and is fixed to the peripheral side of the substrate stage via a connecting plate; the slide is slidably matched with the upper half of the second slide groove, and a plurality of third springs for providing an upward force are arranged at the bottom of the slide, and an airbag and an inflation component for providing a downward force are arranged at the top of the slide, and the inflation component inflates and deflates the airbag to adjust the lifting and lowering of the substrate stage.

[0014] According to certain embodiments of the first aspect of the present application, the method for adjusting the lifting and lowering of the substrate stage according to the height of diamond growth is as follows: As the diamond begins to grow, the air bag is inflated at an initial inflation rate; Setting adjustment cycle, positive pressure tolerance and negative pressure tolerance ; Detect the total pressure applied to the slide by all third springs during each adjustment cycle ; Calculate the expected pressure value for the current regulation cycle ;

[0015] in, is the number of the third spring, is the spring coefficient; is the initial compression of the third spring; is the initial time of the current adjustment cycle, is the average height of diamond growth per unit time; The total pressure measured The expected pressure value within the corresponding adjustment cycle Difference , if the difference is greater than the positive pressure tolerance , then reduce the inflation rate of the next adjustment cycle; if the difference is less than the negative pressure tolerance , the inflation rate of the next adjustment cycle is increased; otherwise, the inflation rate of the next adjustment cycle is kept unchanged.

[0016] In certain embodiments according to the first aspect of the present application, the boss is spliced ​​at the lower half of the second slide groove.

[0017] Compared with the prior art, this application has the following beneficial effects: 1. In the process of the substrate stage rising, the boss below the substrate stage enters the hollow cylinder extending vertically in the middle of the cavity and abuts against the inner wall of the hollow cylinder, thereby isolating the cavity into two parts, preventing the reaction gas, i.e., carbon dioxide, from entering the position below the substrate stage. And as the substrate stage rises, the overlapping area of ​​the hollow cylinder and the boss gradually increases, and the isolation effect is also enhanced, eliminating the limitation of the overlapping area.

[0018] 2. The present application controls the inflation and deflation of the air bag and adjusts the lifting and lowering of the substrate stage, so that the positional relationship between the diamond growth surface and the plasma ball remains relatively fixed, thereby maintaining the uniformity of the diamond growth quality.

[0019] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become readily understood. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, wherein: In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0021] Figure 1 Shown is a schematic diagram of the overall structure of the present application.

[0022] Figure 2 The schematic diagram shows the structure of the plasma reaction chamber of the present application in a working state.

[0023] Figure 3 A schematic structural diagram of the plasma reaction chamber of the present application is shown in a state where a substrate material is placed.

[0024] Figure 4 Shows Figure 2 A partial enlarged view of the connecting mechanism at point A in the middle.

[0025] Figure 5 A schematic diagram showing the locking process of the connection mechanism of the present application.

[0026] Figure 6 A schematic diagram showing the unlocking process of the connection mechanism of the present application is shown.

[0027] Figure 7 Shows Figure 2 A partial enlarged view of the initial state of the adjustment mechanism at B in the middle.

[0028] Figure 8 A schematic diagram showing the adjustment mechanism of the present application for adjusting the descent of the substrate stage.

[0029] Fig. 9 A schematic diagram of the slide installation structure of the present application is shown.

[0030] Description of reference numerals: 100. Microwave system; 101. Microwave source; 102. Waveguide; 103. Mode converter; 104. Three-screw impedance adapter; 105. Plasma ball; 200, plasma reaction chamber; 201, chamber; 202, air inlet; 203, air outlet; 204, hollow cylinder; 205, first plate; 206, first through hole; 2071, branch pipe; 2072, main pipe; 208, observation window; 209, discharge port; 211, substrate stage; 31. Extension; 32. a first connecting portion; 33. Second connecting portion. DETAILED DESCRIPTION

[0031] In order to make the purpose, features, and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0032] Embodiment 1: This embodiment 1 provides a diamond vapor deposition device using carbon dioxide as a carbon source. Figure 1 , including a microwave system 100 and a plasma reaction chamber 200.

[0033] The microwave system 100 is used to generate microwaves, which enter the plasma reaction chamber 200 and excite the reaction gas, ie, carbon dioxide, into a plasma ball 105 .

[0034] Specifically, the microwave system 100 includes a microwave source 101, a waveguide 102, a mode converter 103 and a three-screw impedance adapter 104. The microwave source 101 generates microwaves, and the three-screw impedance adapter 104 matches the impedance to minimize the reflected power. The microwaves are transmitted to the mode converter 103 along the waveguide 102, and enter the plasma reaction chamber 200 under the action of the mode converter 103, and excite the carbon dioxide into a plasma ball 105 above the substrate stage.

[0035] The substrate material is placed in the center of the substrate stage, close to the lower edge of the plasma ball 105, so that diamond grows on the surface of the substrate material.

[0036] Please refer to Figure 2 The plasma reaction chamber 200 includes a chamber body 201 and a liftable substrate stage 211.

[0037] Specifically, the cavity 201 is provided with an air inlet 202 and an air outlet 203, and the air inlet 202 is used to introduce carbon dioxide; a vertically extending hollow cylinder 204 is provided in the middle of the cavity 201, and the axis of the hollow cylinder 204 is opposite to the substrate stage 211, so that the substrate stage 211 can slide in / out of the hollow cylinder 204 during the lifting process.

[0038] In order to fix the hollow cylinder 204, the top of the hollow cylinder 204 is connected to the inner wall of the cavity 201 via a first plate 205. A plurality of first through holes 206 are provided on the first plate 205. The first through holes 206 are connected to the air outlet 203 via pipes, thereby achieving the discharge of exhaust gas.

[0039] In order to facilitate the staff to observe the diamond growth inside the cavity 201 , in this embodiment, an observation window 208 facing the substrate stage 211 is provided on the side wall of the cavity 201 above the first plate 205 .

[0040] The cavity 201 is also provided with a discharge port 209 . The discharge port 209 is opened on the side wall of the cavity 1 below the first flat plate 205 and is used to place the substrate material 210 on the substrate stage 211 .

[0041] It is worth mentioning that the pipeline includes a plurality of branch pipes 2071 and a main pipe 2072, the number of the branch pipes 2071 corresponds to the number of the first through holes 206, and the tops of the branch pipes 2071 are connected to the first through holes 206 one by one, and the bottoms of the branch pipes 2071 are connected to the main pipe 2072, and the gas outlet 203 is arranged on the main pipe 2072 and extends to the outside of the cavity 201. The outside of the gas outlet 203 can also be connected to an air pump to extract the reaction gas inside.

[0042] A substrate material 210 is placed on the upper surface of the substrate stage 211, and a boss 212 is provided below the substrate stage 211. When the substrate stage 211 rises, the boss 212 is in contact with the inner wall of the hollow cylinder 204, thereby isolating the upper and lower parts of the cavity 201, preventing the reaction gas, i.e., carbon dioxide, from entering the lower part of the cavity 201, thereby improving the utilization rate of the reaction gas.

[0043] Please refer to Figure 3 In normal state, the substrate stage 211 is at a low position, and the substrate material 210 is placed on the substrate stage 211 through the discharge port 209. Then the substrate stage 211 rises until it reaches a preset growth height, preferably the substrate stage 211 is level with the first plate 205, that is, Figure 2 Status shown.

[0044] exist Figure 2 In the state shown, the diamond growth reaction can be carried out by introducing the reaction gas. During the reaction process, the boss 212 needs to be maintained at this height. Therefore, a connection mechanism for maintaining the height of the boss 212 is provided between the boss 212 and the first plate 205.

[0045] Please refer to Figure 4 The connecting mechanism includes an extension portion 31, a first connecting portion 32 and a second connecting portion 33.

[0046] Please combine Figure 2 and Figure 4 The extension portion 31 is disposed on the side wall of the boss 212 and extends outward.

[0047] The first connecting portion 32 is arranged on the upper side of the extension portion 31, and the first connecting portion 32 includes a vertically extending first slot 321. A plurality of horizontally extending first sliding slots 322 are arranged at the same height on the side walls of the first slot 321. A locking tongue 323 and a first spring 324 are slidably arranged in each first sliding slot 322. The first spring 324 provides pressure for the locking tongue 323 toward the center of the first slot 321, so that the end of the locking tongue 323 extends into the first slot 321. The locking tongue 323 is provided with a first slope 3231 arranged obliquely upward at one end facing the first slot 321.

[0048] The second connecting portion 33 is disposed at the lower side of the first plate 205. The second connecting portion 33 includes a connecting rod 331 fixedly connected to the first plate 205. The connecting rod 331 faces the first slot 321. A locking strip 332 is fixedly disposed at the lower end of the connecting rod 331. The edge of the locking strip 332 is provided with a second slope 3321 that is inclined downward. Figure 5 As shown, during the rising process of the substrate stage, the first slope 3231 and the second slope 3321 come into contact with each other. Under the force of mutual squeezing, the locking tongue 323 moves in a direction away from the center of the first slot 321, and the locking tongue moves to the upper side of the locking bar 332. Figure 4 In the corresponding state, the locking strip 332 limits the height of the locking tongue 323 , thereby maintaining the boss 212 at the height.

[0049] At the same time, in order to release the height limitation of the locking tongue 323 by the fixing bar 332, an unlocking bar 333 is slidably arranged on the connecting rod 331 in this embodiment, and the edge of the unlocking bar 333 is provided with a third slope 3331 obliquely upward. Figure 4 In the state, the boss 212 and the substrate stage 211 continue to be pushed up. When the substrate stage 211 continues to rise, the lock tongue 323 moves to the upper side of the unlocking bar 333. At this time, the third slope 3331 contacts the lower side of the lock tongue 323, and the substrate stage 211 is pushed down. Under the pushing action of the third slope 3331, as shown in FIG. Figure 6 As shown, first, the unlocking strip 333 slides downward until it fits with the locking strip 332, and then the third slope 3331 causes the locking tongue 323 to move in a direction away from the center of the first slot 321, and the locking tongue 323 moves downward to the lower side of the locking strip 332, that is, Figure 5 In the corresponding state, the locking tongue 323 is separated from the locking bar 332, and the unlocking is completed. At this time, the boss 212 and the substrate stage 211 can descend freely.

[0050] In order to prevent the unlocking bar 333 from interfering with the lock tongue 323 during the locking process, a certain distance needs to be maintained between the unlocking bar 333 and the locking bar 333 under normal conditions. In this embodiment, a second spring 334 is provided between the locking bar 332 and the unlocking bar 333 to provide an upward force for the unlocking bar 333, specifically a compression spring.

[0051] At the same time, in order to ensure that the locking bar 332 and the unlocking bar 333 can be smoothly attached to each other during the unlocking process, and avoid the obstruction of the second spring 334 therebetween, at least one of the locking bar 332 and the unlocking bar 333 is provided with a receiving groove 335, and the receiving groove 335 is used to accommodate the second spring 334 when the locking bar 332 and the unlocking bar 333 are attached to each other. Preferably, in this embodiment, the receiving groove 335 is respectively provided on the side opposite to the locking bar 332 and the unlocking bar 333.

[0052] Embodiment 2: During the diamond growth process, diamond is gradually deposited on the upper surface of the substrate material 210, causing the deposition surface to rise higher and higher. The position of the deposition surface and the plasma above changes, which will affect the uniformity of the diamond growth quality to a certain extent.

[0053] In order to avoid the above situation, in this embodiment, an adjustment mechanism is provided in the boss 212 to adjust the elevation of the substrate stage according to the height of the diamond growth.

[0054] For details, please refer to Figure 7 and Fig. 9 The bottom of the substrate stage 211 is columnar, and the boss 212 is sleeved on the outer side of the substrate stage 211. The boss 212 and the substrate stage 211 can slide up and down relatively.

[0055] The adjusting mechanism includes a second sliding groove 41 and a sliding platform 42 .

[0056] The second slide groove 41 is in the shape of a ring extending in the vertical direction, with an upper half completely located in the boss 212 , and a lower half of the second slide groove 41 forming an opening 411 on the inner wall of the boss 212 .

[0057] The slide 42 is in the shape of a ring extending in the vertical direction. Fig. 9 As shown, the slide 42 is fixed to the peripheral side of the substrate stage 211 via a horizontally arranged connecting plate 421. The slide 42 is slidably matched with the upper half of the second slide groove 41, and the connecting plate 421 extends from the opening 411 and is connected to the substrate stage 211. The height of the opening 411 can be set according to actual conditions to meet the lifting and lowering of the substrate stage 211 relative to the boss 212.

[0058] The bottom of the slide 42 is provided with a plurality of third springs 43 for providing an upward force, so as to lift up the substrate stage 211 in the initial state. The top of the slide 42 is provided with an air bag 44 and an inflatable component 45 for providing a downward force. The inflatable component 45 inflates and deflates the air bag 44 to adjust the lifting and lowering of the substrate stage 211. Specifically, Figure 8 As shown, as the diamond grows higher, in order to make the growth surface of the diamond fit the plasma ball 105 as closely as possible, the inflation component 45 inflates the airbag 44 to adjust the substrate stage 211 to descend relative to the boss 212 .

[0059] It is worth mentioning that in order to realize the installation of the slide 42, the boss 212 adopts a split design and is spliced ​​at the lower half of the second slide 41. During installation, the airbag 44 and the inflatable component 45 are first installed in the upper half of the second slide 41, and then the slide 42 is placed in the upper half of the second slide 41, and finally the split boss is connected by welding or bolts.

[0060] This embodiment further proposes a method for adjusting the lifting and lowering of the substrate stage according to the height of the diamond growth, which is as follows: S1, inflate the airbag at the initial inflation rate while the diamond starts to grow; S2, setting adjustment cycle, positive pressure tolerance and negative pressure tolerance ; S3, detects the total pressure applied to the slide by all third springs in each adjustment cycle ; It is worth mentioning that the detection of the total pressure F is achieved by installing a pressure sensor between the third spring 43 and the sliding sleeve 42 .

[0061] S4, calculate the expected pressure value of the current adjustment cycle ;

[0062] in, is the number of the third spring, is the spring coefficient; is the initial compression of the third spring; is the initial time of the current adjustment cycle, It is the average height of diamond growth per unit time, which is calculated by the average value of the results of multiple test experiments.

[0063] S5, the measured total pressure The expected pressure value within the corresponding adjustment cycle Difference .

[0064] If the difference is greater than the positive pressure tolerance , it means that the current pressure is too high, the compression of the third spring is greater than expected, and the inflation of the airbag 44 is in an oversaturated state. If you want to adjust to the expected state in the next cycle, you should reduce the inflation rate of the next adjustment cycle. On the contrary, if the difference is less than the negative pressure tolerance , then increase the inflation rate of the next adjustment cycle; otherwise, the difference is within the positive pressure tolerance and negative pressure tolerance Just keep the inflation rate of the next adjustment cycle unchanged.

[0065] Through the above method, the height of the substrate stage can be fine-tuned during the diamond growth process to adapt it to the growth rate of the diamond and ensure its uniform growth quality.

[0066] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0067] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0068] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A diamond vapor deposition device using carbon dioxide as a carbon source, characterized in that: include: A microwave system for generating microwaves, wherein the microwaves enter the plasma reaction chamber to excite the carbon dioxide into a plasma ball; A plasma reaction chamber, comprising a chamber body and a liftable substrate stage; The cavity is provided with an air inlet and an air outlet, the air inlet is used to introduce carbon dioxide; a vertically extending hollow cylinder is provided in the middle of the cavity, the axis of the hollow cylinder is directly facing the substrate stage, the top of the hollow cylinder is connected to the inner wall of the cavity via a first flat plate, the first flat plate is provided with a plurality of first through holes, and the first through holes are connected to the air outlet via pipelines; A boss is arranged below the substrate stage. When the substrate stage rises, the boss is attached to the inner wall of the hollow cylinder to form isolation. A connecting mechanism for maintaining the height of the boss is arranged between the boss and the first flat plate.

2. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 1, characterized in that: The microwave system includes the diamond vapor deposition equipment using carbon dioxide as the carbon source according to claim 4, characterized in that it includes a microwave source, a waveguide, a mode converter and a three-screw impedance adapter; the microwave source generates microwaves, the three-screw impedance adapter matches the impedance, the microwaves are transmitted along the waveguide to the mode converter, and enter the plasma reaction chamber under the action of the mode converter, and the carbon dioxide is excited into a plasma ball above the substrate table.

3. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 1, characterized in that: The connecting mechanism comprises: An extension portion, arranged on the side wall of the boss and extending outwards; A first connecting portion is arranged on the upper side of the extension portion, the first connecting portion comprises a first slot extending vertically, a plurality of first sliding slots extending horizontally are arranged at the same height on the side wall of the first slot, a locking tongue and a first spring are slidably arranged in each first sliding slot, the first spring provides pressure for the locking tongue toward the center of the first slot, and a first slope arranged obliquely upward is arranged at one end of the locking tongue facing the first slot; The second connecting part is arranged on the lower side of the first flat plate, and the second connecting part includes a connecting rod connected to the first flat plate, the connecting rod is opposite to the first slot, and a locking strip is fixedly provided on the lower end of the connecting rod, and a second slope slanting downward is provided on the edge of the locking strip; when the substrate stage rises, the first slope and the second slope contact, so that the locking tongue moves in a direction away from the center of the first slot, and the locking tongue moves to the upper side of the locking strip, and the locking strip forms a height limit for the locking tongue.

4. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 3, characterized in that: An unlocking bar is slidably provided on the connecting rod, and a third slope obliquely upward is provided on the edge of the unlocking bar; when the substrate stage continues to rise, the locking tongue moves to the upper side of the unlocking bar; when the substrate stage descends, the third slope contacts the lower side of the locking tongue, and first the unlocking bar slides downward until it fits with the locking bar, and then the third slope causes the locking tongue to move in a direction away from the center of the first slot, and the locking tongue then moves downward to the lower side of the locking bar, and the locking tongue is separated from the locking bar.

5. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 4, characterized in that: A second spring for providing an upward force to the unlocking bar is arranged between the locking bar and the unlocking bar.

6. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 5, characterized in that: At least one of the locking bar and the unlocking bar is provided with a receiving groove, and the receiving groove is used to receive the second spring when the locking bar and the unlocking bar are in contact with each other.

7. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 1, characterized in that: An adjusting mechanism is arranged inside the boss to adjust the lifting and lowering of the substrate table according to the height of the diamond growth.

8. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 7, characterized in that: The bottom of the substrate stage is columnar, and the boss is sleeved on the outer side of the substrate stage; the adjustment mechanism includes a second slide groove and a slide table; The second chute is in the shape of a ring extending in the vertical direction, the upper half of which is completely located in the boss, and the lower half of which is an opening on the inner wall of the boss; The slide is in the shape of a ring extending in the vertical direction, and is fixed to the peripheral side of the substrate stage via a connecting plate; the slide is slidably matched with the upper half of the second slide groove, and a plurality of third springs for providing an upward force are arranged at the bottom of the slide, and an airbag and an inflation component for providing a downward force are arranged at the top of the slide, and the inflation component inflates and deflates the airbag to adjust the lifting and lowering of the substrate stage.

9. The diamond vapor deposition apparatus using carbon dioxide as a carbon source according to claim 8, characterized in that: The method for adjusting the height of the substrate stage according to the height of diamond growth is as follows: As the diamond begins to grow, the air bag is inflated at an initial inflation rate; Setting adjustment cycle, positive pressure tolerance and negative pressure tolerance ; Detect the total pressure applied to the slide by all third springs during each adjustment cycle ; Calculate the expected pressure value for the current regulation cycle ; in, is the number of the third spring, is the spring coefficient; is the initial compression of the third spring; is the initial time of the current adjustment cycle, is the average height of diamond growth per unit time; The total pressure measured The expected pressure value within the corresponding adjustment cycle Difference , if the difference is greater than the positive pressure tolerance , then reduce the inflation rate of the next adjustment cycle; if the difference is less than the negative pressure tolerance , the inflation rate of the next adjustment cycle is increased; otherwise, the inflation rate of the next adjustment cycle is kept unchanged.

10. The diamond vapor deposition device using carbon dioxide as a carbon source according to claim 8, characterized in that: The boss is formed by splicing at the lower half of the second chute.

Images