A plasma chemical vapor deposition system based on lateral growth of single crystal diamond

Abstract

The application discloses a kind of plasma chemical vapor deposition systems based on single crystal diamond lateral growth, it is related to diamond production technical field.The system includes: plasma reaction cavity, for generating plasma ball;Subbase cavity is communicated with the plasma reaction cavity;Subbase cavity is provided with subbase, and the inner wall of subbase cavity is provided with flexible film at first height, the middle part of the flexible film is sealedly connected with a mounting ring, and the mounting ring is detachably connected with the subbase;When mounting ring is connected with the subbase, the flexible film, mounting ring and subbase divide subbase cavity into two parts;Three-axis drive mechanism is used to drive the movement of the subbase;To realize the movement of subbase relative to / back away from mounting ring and the lateral movement of subbase and plasma ball.The application enables the substrate material to move laterally relative to the plasma ball during diamond growth, forming the effect of diamond material growth along the lateral direction.

Description

[0001] Cross-reference to related applications

[0002] This application is a divisional application of Chinese patent application No. 2024108857948, filed on July 3, 2024, entitled "An auxiliary device for lateral growth of single crystal diamond and its working method". Technical Field

[0003] This invention relates to the field of diamond production technology, and in particular to an auxiliary device for the lateral growth of single-crystal diamond and its working method. Background Technology

[0004] Diamond, due to its superior properties, has a wide range of applications in many fields. Natural diamonds are scarce and expensive, making it difficult to meet the large-scale demands of various industries. Synthetic diamonds prepared using the high-temperature, high-pressure (HTHP) method contain metal catalysts, which also affect their properties. Currently, microwave plasma chemical vapor deposition (MPCVD) technology can grow high-quality synthetic diamonds on substrate materials.

[0005] However, the growth size of diamond materials prepared by existing microwave plasma chemical vapor deposition technology is limited by the size of the plasma sphere; that is, the larger the plasma sphere, the larger the diamond material grown. But as the size of the plasma sphere increases, the density of the plasma sphere gradually decreases, leading to a decrease in the quality of the diamond material.

[0006] Therefore, designing a device that can free the size of the grown diamond material from the limitations of plasma sphere size is one of the urgent problems to be solved. Summary of the Invention

[0007] In order to solve at least one of the technical problems mentioned in the background art, the present invention aims to provide a single crystal diamond lateral growth auxiliary device and its working method, which enables the substrate material to move laterally relative to the plasma ball during the diamond growth process, thereby forming the effect of diamond material growing laterally.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A device for assisting in the lateral growth of single-crystal diamond includes:

[0010] A plasma reaction chamber is used to connect to a microwave system to generate a plasma sphere;

[0011] A base cavity is disposed at the bottom of the plasma reaction chamber and is connected to the plasma reaction chamber; a base is disposed inside the base cavity, and a flexible film is disposed on the inner wall of the base cavity at a first height; a mounting ring is sealed and connected to the middle of the flexible film, and the mounting ring is detachably connected to the base; when the mounting ring is connected to the base, the flexible film, the mounting ring, and the base divide the base cavity into upper and lower parts;

[0012] A three-axis drive mechanism is used to drive the base to move; the three-axis drive mechanism drives the base to rise and fall, so as to realize the base moving relative to / away from the mounting ring; the three-axis drive mechanism drives the base to move in the horizontal plane, so as to realize the lateral movement of the base and the plasma ball.

[0013] In some embodiments of the present invention, the first height of the base cavity is provided with a first mounting portion for connecting a flexible film, and the first mounting portion is sealed to the outer edge of the flexible film.

[0014] In some embodiments of the present invention, the first mounting part is annular, and an air extraction port is provided on the first mounting part. The bottom of the air extraction port is connected to an air extraction pipe extending to the outside of the base cavity.

[0015] In some embodiments of the present invention, the mounting ring and the base are threaded together.

[0016] In some embodiments of the present invention, the three-axis drive mechanism includes:

[0017] The first slide rail is horizontally and fixedly connected to one side of the base cavity, and a first slider is slidably fitted on the first slide rail.

[0018] The second slide rail is arranged horizontally and fixedly connected to the first slider, and the second slider is slidably fitted on the second slide rail.

[0019] A telescopic cylinder is arranged vertically and fixedly connected to the second slider, with the telescopic end of the cylinder connected to the base.

[0020] In some embodiments of the present invention, a sliding sleeve is provided at the bottom of the base, the sliding sleeve is slidably engaged with the telescopic end of the telescopic cylinder in the vertical direction, a motor is provided inside the telescopic end of the telescopic cylinder, a connecting piece is fixedly connected to the output end of the motor, and a sliding groove is provided inside the sliding sleeve that is slidably engaged with the connecting piece in the vertical direction and limited in the horizontal direction; when the motor is working, the base rotates with the connecting piece and the base can slide relative to the telescopic end in the vertical direction.

[0021] In some embodiments of the present invention, a mounting platform for placing a mounting ring is provided in the base cavity at a second height lower than the first height. At the point where the mounting platform and the mounting ring are in contact, one of them is provided with a circumferential limit strip, and the other is provided with a corresponding limit groove to prevent the mounting ring from rotating relative to the mounting platform.

[0022] In some embodiments of the present invention, the flexible film is made of silicon dioxide.

[0023] A method for operating a single-crystal diamond lateral growth auxiliary device includes the following steps:

[0024] S1, Place the substrate material on the stage;

[0025] S2, drive the base to rise until the base contacts the mounting ring;

[0026] S3 connects the mounting ring to the base, dividing the base cavity into upper and lower parts;

[0027] S4, drive the stage to continue rising until the substrate material comes into contact with the plasma sphere;

[0028] S5 drives the stage to move laterally, which is equivalent to the movement of a plasma ball, causing diamond to grow laterally along the substrate material.

[0029] In some embodiments of the present invention, in step S3, the connection method between the mounting ring and the base is as follows:

[0030] The motor drives the connecting piece to rotate, and the base rotates with the connecting piece to form a relative rotation between the base and the mounting ring; the base and the mounting ring approach each other under the action of the threaded engagement, and in this process, the connecting piece and the sliding groove form a vertical relative movement.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] The present invention provides a mounting ring in the abutment cavity, and the mounting ring is set at a first height in the abutment cavity via a flexible film. The abutment and the mounting ring are detachably connected, and the flexible film can adapt to the lateral movement of the abutment, thereby realizing the lateral growth of diamond. On the other hand, when the abutment and the mounting ring are connected, the abutment cavity is divided into upper and lower parts. During the reaction process, the reaction gas can be prevented from entering the lower part, thereby improving the utilization rate of the reaction gas. Attached Figure Description

[0033] Figure 1 For existing plasma chemical vapor deposition systems.

[0034] Figure 2 This invention relates to an improved plasma chemical vapor deposition system.

[0035] Figure 3 This is a schematic diagram of the overall structure of the present invention.

[0036] Figure 4 This is a top cross-sectional view of the first mounting part of the present invention.

[0037] Figure 5 This is a schematic diagram of the three-axis drive mechanism of the present invention.

[0038] Figure 6 This is a schematic diagram of the base bottom structure of the present invention.

[0039] Figure 7 This is a schematic diagram of the lateral growth of diamond according to the present invention.

[0040] Figure 8 This is a schematic diagram of the base position in the first state of the present invention.

[0041] Figure 9 This is a schematic diagram of the base position in the second state of the present invention.

[0042] Figure 10 This is a schematic diagram of the base position in the third state of the present invention.

[0043] Figure 11 This is a schematic diagram of the base position in the fourth state of the present invention.

[0044] Figure 12 This is a schematic diagram of the overall structure in the fourth state of the present invention. Detailed Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Example 1:

[0047] like Figure 1 As shown, the existing plasma chemical vapor deposition system mainly consists of a microwave system a1 and a reaction chamber a2. Its working principle is as follows: Microwave source a11 generates microwaves, which are transmitted along waveguide a12 to a mode converter. Under the action of mode converter 13, the microwaves enter the reaction chamber a2 through a quartz window and are excited into a plasma sphere a23 above the stage a21. A three-screw impedance tuner a14 is installed on the waveguide a12 to match the impedance and minimize reflected power. The substrate material a22 is placed in the center of the stage a21, close to the lower edge of the plasma sphere a23. Then, reactive gases (CH4, H2) are introduced through the inlet, thereby growing diamond on the surface of the substrate material.

[0048] However, in this system, the growth size of the diamond material is limited by the size of the plasma sphere.

[0049] Example 2:

[0050] To address the problems in Example 1, this example improves the reaction chamber a2 in the plasma chemical vapor deposition system. Specifically, this example proposes a single-crystal diamond lateral growth auxiliary device a3 to replace the reaction chamber a2 in Example 1, enabling the stage to move relative to the plasma sphere along the horizontal plane during diamond deposition, thereby achieving lateral diamond growth.

[0051] For details, please refer to Figure 2 and Figure 3 The single-crystal diamond lateral growth auxiliary device a3 includes a plasma reaction chamber 11, a base chamber 12, and a triaxial drive mechanism 2.

[0052] The plasma reaction chamber 11 is used to connect to the microwave system a1. A quartz window 110 is provided on the top of the plasma reaction chamber 11. The microwaves generated by the microwave system a1 enter the plasma reaction chamber through the quartz window 110 to generate a plasma ball 10.

[0053] It is worth mentioning that several air inlets are also provided on the periphery of the top of the plasma reaction chamber 11 to allow the reaction gases (CH4, H2) to enter and exit.

[0054] The base cavity 12 is disposed at the bottom of the plasma reaction cavity 11 and is connected to the plasma reaction cavity 11.

[0055] A base 13 is provided inside the base cavity 12. A flexible film 15 is provided on the inner wall of the base cavity 12 at a first height. A mounting ring 16 is sealed and connected to the middle of the flexible film 15. The mounting ring 16 is detachably connected to the base 13.

[0056] Meanwhile, a discharge port 121 is also provided on the base cavity 12 for placing the substrate material 14 on the base 13.

[0057] The flexible film is made of silicon dioxide, but other chemically stable and flexible materials can also be used.

[0058] like Figure 10As shown, when the mounting ring 16 is connected to the base 13, the flexible film 15, mounting ring 16, and base 13 divide the base cavity into upper and lower parts. In this state, the reactive gases (CH4, H2) can be concentrated in the upper part of the plasma reaction chamber 11 and the base cavity 12 for reaction. The lower part of the base cavity 12 is mainly used to install the triaxial drive mechanism. If the reactive gases (CH4, H2) enter the lower part, they cannot participate in the diamond material formation reaction, which will lead to a large waste of reactive gases (CH4, H2).

[0059] To facilitate the installation of the flexible film 15, a first mounting part 151 for connecting the flexible film 15 is provided at the first height of the base cavity 12. The first mounting part 151 is sealed to the outer edge of the flexible film 15.

[0060] Please refer to Figure 3 and Figure 4 The first mounting portion 151 is annular, and an exhaust port 152 is provided on the first mounting portion 151. The bottom of the exhaust port 152 is connected to an exhaust pipe 153 extending to the outside of the base cavity 12. This allows the (initial) air or reaction gas in the plasma reaction chamber 11 and the upper part of the base cavity 12 to be discharged.

[0061] The three-axis drive mechanism 2 is used to drive the base 13 to move. The drive of the three-axis drive mechanism 2 is divided into two types:

[0062] 1. The three-axis drive mechanism 2 drives the base 13 to move up and down, thereby enabling the base 13 to move relative to / away from the mounting ring 16. Its function is to connect / disconnect the base 13 and the mounting ring 16.

[0063] Second, the triaxial drive mechanism 2 drives the base 13 to move in the horizontal plane, thereby realizing the lateral movement of the base 13 and the plasma ball 10. Its function is to enable the plasma ball 10 to deposit at different positions on the substrate material 14.

[0064] like Figure 7 As shown, the dashed circles on the substrate material 14 represent the diamond deposited on the substrate material 14 by the plasma sphere 10 at a certain moment. When the plasma sphere 10 is equivalent to the abutment 14 along... Figure 7 When the stage moves laterally in the direction indicated by the middle arrow, deposition occurs at different locations on the substrate material, which is called lateral growth. Therefore, it is only necessary to control the stage 10 to move laterally along the horizontal plane. Figure 7 Large areas of diamond material can be generated by moving in the opposite direction of the middle arrow.

[0065] Please combine Figure 3 and Figure 5 The three-axis drive mechanism 2 includes:

[0066] The first slide rail 21 is horizontally and fixedly connected to one side of the base cavity 12, and the first slide rail 21 is slidably fitted with a first slider 22.

[0067] The second slide rail 23 is arranged in a horizontal direction and is fixedly connected to the first slider 22. The second slider 24 is slidably fitted on the second slide rail 23.

[0068] The telescopic cylinder 25 is arranged vertically and fixedly connected to the second slider 24. The telescopic end of the telescopic cylinder is connected to the base 13.

[0069] The above structure enables the base 13 to move laterally in the plane and vertically.

[0070] It is worth mentioning that, in order to further improve stability, the first slide rail 21 and the first slider 22 are each provided in two sets, which are respectively located on both sides of the second slide rail 23.

[0071] In this embodiment, the mounting ring 16 and the base 13 are threaded together. Therefore, during the mating process of the mounting ring 16 and the base 13, the base 13 needs to rotate.

[0072] To achieve the above objectives, in this embodiment, a sliding sleeve 131 is provided at the bottom of the base 13. The sliding sleeve 131 is slidably engaged with the telescopic end of the telescopic cylinder 25 in the vertical direction. A motor 26 is provided inside the telescopic end of the telescopic cylinder 25. A connecting piece 261 is fixedly connected to the output end of the motor 26. A sliding groove 132 is provided inside the sliding sleeve 131, which is slidably engaged with the connecting piece 261 in the vertical direction and is limited in the horizontal direction.

[0073] When the motor is working, the base 13 rotates with the connecting piece 261 and the base 13 can slide in the vertical direction relative to the telescopic end to achieve threaded engagement with the mounting ring 16.

[0074] At the same time, in order to achieve threaded engagement, the mounting ring 16 needs to be placed at a specific height in advance and limited in the circumferential direction to prevent the mounting ring 16 and the base 13 from rotating synchronously, which would prevent the threaded engagement from being achieved.

[0075] Therefore, please refer to Figure 3 , Figures 8 to 11 A mounting platform 17 for placing the mounting ring 16 is provided at a second height below the first height inside the base cavity 12. At the point where the mounting platform 17 and the mounting ring 16 fit together, one of them is provided with a circumferential limit strip, and the other is provided with a corresponding limit groove to prevent the mounting ring 16 from rotating relative to the mounting platform 17.

[0076] In this embodiment, the mounting platform 17 is provided with a limiting strip 171 circumferentially, and the mounting ring 16 is provided with a corresponding limiting groove 161. The planar arrangement of these grooves can be referred to... Figure 4 Four dashed boxes are set at intervals along the outer edge of the central base 13.

[0077] It is worth mentioning that, in order to improve the sealing effect between the base 13 and the mounting ring 16, the upper surface of the base 13 and the lower surface of the mounting ring 16 are provided with interlocking stepped structures.

[0078] Example 3:

[0079] This embodiment provides a plasma chemical vapor deposition system based on the lateral growth of single-crystal diamond, including a microwave system and an auxiliary device for the lateral growth of single-crystal diamond as described in Embodiment 2.

[0080] Example 4:

[0081] This embodiment provides a method for operating the single-crystal diamond lateral growth auxiliary device described in Embodiment 2 above, including the following steps:

[0082] S1, please refer to Figure 3 and Figure 8 Lower the base 13 until it is at the same height as the inlet 121, and place the substrate material 14 on the base 13.

[0083] S2, as Figure 9 As shown, drive the base 13 to rise until the base 13 contacts the mounting ring 16. Since the base 13 and the mounting ring 16 are threaded together, the upward movement of the base 13 should be stopped immediately at this point.

[0084] S3 connects the mounting ring 16 to the base 13, dividing the base cavity 12 into upper and lower parts; the specific connection method is as follows:

[0085] like Figure 9 and Figure 10 As shown, the motor 26 drives the connecting piece 261 to rotate. Due to the circumferential restriction of the mounting ring 16 by the limiting strip 171 and the limiting groove 16, the base 13 rotates with the connecting piece 261 to form a relative rotation between the base 13 and the mounting ring 16. The base 13 and the mounting ring 16 approach each other under the action of the threaded engagement. During this process, the connecting piece 261 and the sliding groove 132 form a vertical relative movement.

[0086] S4, after the mounting ring 16 is connected to the base 13, as follows Figure 11 and Figure 12 As shown, the driving platform 13 continues to rise until the substrate material 14 comes into contact with the plasma ball 10.

[0087] S5 drives the base 13 to move laterally, equivalent to the plasma ball 10, so that diamond grows laterally along the substrate material 14, thereby realizing the preparation of large-area diamond material.

[0088] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A system for plasma chemical vapor deposition based on lateral growth of single crystal diamond, characterized in that, Includes a microwave system and an auxiliary device for the lateral growth of single-crystal diamond; The single-crystal diamond lateral growth auxiliary device includes: A plasma reaction chamber is used to connect to a microwave system to generate a plasma sphere; A base cavity is disposed at the bottom of the plasma reaction chamber and is connected to the plasma reaction chamber; a base is disposed inside the base cavity, and a flexible film is disposed on the inner wall of the base cavity at a first height; a mounting ring is sealed and connected to the middle of the flexible film, and the mounting ring is detachably connected to the base; when the mounting ring is connected to the base, the flexible film, the mounting ring, and the base divide the base cavity into upper and lower parts; A three-axis drive mechanism is used to drive the base to move; the three-axis drive mechanism drives the base to rise and fall, so as to realize the base moving relative to / away from the mounting ring; the three-axis drive mechanism drives the base to move in the horizontal plane, so as to realize the lateral movement of the base and the plasma ball. The mounting ring and the base are threaded together. A mounting platform for placing a mounting ring is provided at a second height below the first height inside the base cavity. At the point where the mounting platform and the mounting ring fit together, one of them is provided with a circumferential limit strip, and the other is provided with a corresponding limit groove to prevent the mounting ring from rotating relative to the mounting platform. The three-axis drive mechanism includes: The first slide rail is horizontally and fixedly connected to one side of the base cavity, and a first slider is slidably fitted on the first slide rail. The second slide rail is arranged horizontally and fixedly connected to the first slider, and the second slider is slidably fitted on the second slide rail. A telescopic cylinder is arranged vertically and fixedly connected to the second slider, and the telescopic end of the telescopic cylinder is connected to the base. The base is provided with a sliding sleeve at its bottom. The sliding sleeve slides vertically with the telescopic end of the telescopic cylinder. A motor is provided inside the telescopic end of the telescopic cylinder. A connecting piece is fixedly connected to the output end of the motor. A sliding groove is provided inside the sliding sleeve that slides vertically with the connecting piece and is limited in the horizontal direction. When the motor is working, the base rotates with the connecting piece and the base can slide vertically relative to the telescopic end.

2. A system for plasma chemical vapor deposition based on lateral growth of single crystal diamond according to claim 1, characterized in that, The base cavity is provided with a first mounting part for connecting a flexible film at a first height, and the first mounting part is sealed to the outer edge of the flexible film.

3. The plasma chemical vapor deposition system based on the lateral growth of single-crystal diamond according to claim 2, characterized in that, The first mounting part is annular, and an air extraction port is provided on the first mounting part. The bottom of the air extraction port is connected to an air extraction pipe extending to the outside of the base cavity.

4. The plasma chemical vapor deposition system based on the lateral growth of single-crystal diamond according to claim 1, characterized in that, There are two sets of the first slide rail and the first slider, which are respectively set on both sides of the second slide rail.

5. The plasma chemical vapor deposition system based on the lateral growth of single-crystal diamond according to claim 1, characterized in that, The flexible film is made of silicon dioxide.

6. The plasma chemical vapor deposition system based on the lateral growth of single-crystal diamond according to claim 1, characterized in that, The upper surface of the base and the lower surface of the mounting ring are provided with interlocking stepped structures.

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