Large-size diamond growth MPCVD device capable of preventing airflow impact

Abstract

The utility model relates to a large-size diamond growth MPCVD device capable of preventing airflow impact, and belongs to the related field of diamond preparation. The reaction device comprises a reaction cavity, an outer ring cooling cavity, an inner ring gas uniformizing cavity, a process gas buffer cavity and a process gas inlet system, the outer ring cooling cavity is arranged at the top of an outer ring of a cavity body of the reaction cavity, the upper portion of the outer ring cooling cavity is connected with the process gas buffer cavity, and the inner ring gas uniformizing cavity is arranged at the top of the center of the cavity body of the reaction cavity. The reaction cavity is isolated from the process gas buffer cavity by the inner ring gas uniformizing cavity; and process gas inlet systems are symmetrically arranged on two sides of the upper sealing cover of the cavity at the top of the process gas buffer cavity. The device is reasonable in structural design, safe and reliable, when the downward microwave feeding mode is adopted, after airflow enters from the upper portion of the cavity, the airflow is prevented from impacting a diamond substrate, the uniformity of diamond is improved, and the use requirement is met.

Description

Technical Field

[0001] The utility model relates to a device, in particular to a large-size diamond growth MPCVD device for preventing air flow impact, which belongs to the field related to diamond preparation. Background Technique

[0002] Large-size diamond growth MPCVD device: namely, microwave plasma chemical vapor deposition equipment, also called MPCVD (Microwave Plasma Chemical Vapor Deposition), is a device used to grow large-size single-crystal and polycrystalline diamonds, and the size of the grown diamonds can reach 4-6 inches.

[0003] Air flow impact: refers to the microwave plasma chemical vapor deposition equipment for growing large-size diamonds. Due to the large intake of gas and the fast intake rate, a large impact force will be generated when the gas just enters, forming an air flow impact.

[0004] Plasma: is an ionized gaseous substance composed of positive and negative ions generated after partial electrons of atoms and atomic groups are deprived and then ionized.

[0005] The main methods for synthesizing artificial diamonds include high temperature and high pressure method (HTHP), microwave plasma chemical vapor deposition method (MPCVD), direct current arc plasma jet method (DCAPJ) / hot filament chemical vapor deposition method (HFCVD), etc. The MPCVD method has the advantages of high plasma energy density, low impurity content, good controllability, etc., and is one of the most potential methods for synthesizing high-quality diamonds. The working principle of the MPCVD equipment is that the microwave generated by the microwave generator enters the reaction chamber of the reaction equipment through the waveguide transmission system, and a mixed gas such as methane and hydrogen is introduced into the reaction chamber. Under the excitation of the microwave, glow discharge is generated in the reaction chamber, the molecules of the reaction gas are ionized to generate plasma, and a diamond film is deposited on the diamond substrate.

[0006] Currently, in the aspect of large-size diamond growth MPCVD devices for preventing air flow impact, there is no solution similar to the present utility model in the type of downward microwave equipment.

[0007] In the prior art, for a large-sized diamond growth MPCVD device that prevents air flow impact, a device for introducing a mixed gas such as methane and hydrogen into the reaction chamber of the MPCVD device. In order to make the gas distribute more evenly in the chamber after entering, the gas inlets are generally distributed at the center position of the chamber cover directly above the chamber, or several air inlets are evenly distributed on the chamber cover. In such a large-sized MPCVD device, due to the relatively large gas flow rate, the impact force of the gas is relatively large when it suddenly enters the vacuum chamber, which will cause the diamond substrate above the workbench to be blown off its original position or even blown off the workbench, thus affecting the growth of diamond crystals. Summary of the Utility Model

[0008] The purpose of the present utility model is to overcome the above-mentioned deficiencies existing in the prior art, and to provide a large-sized diamond growth MPCVD device that prevents air flow impact, with a reasonable structural design, safe and reliable. When adopting the form of feeding microwave from below, after the air flow enters from above the chamber, it avoids the air flow impact on the diamond substrate and improves the uniformity of diamond.

[0009] The technical solution adopted by the present utility model to solve the above problems is: The large-sized diamond growth MPCVD device that prevents air flow impact includes a reaction chamber, an outer ring cooling chamber, an inner ring gas homogenizing chamber, a process gas buffer chamber, and a process gas inlet system. It is characterized in that: the outer ring cooling chamber is arranged at the top of the outer ring of the reaction chamber, and the upper part of the outer ring cooling chamber is connected to the process gas buffer chamber. The inner ring gas homogenizing chamber is arranged at the top of the center of the reaction chamber, and the inner ring gas homogenizing chamber isolates the reaction chamber from the process gas buffer chamber. The process gas inlet system is symmetrically arranged on both sides of the top of the process gas buffer chamber; the reaction chamber includes a workbench, a quartz ring, a diamond substrate, and a plasma. The workbench is located at the center of the reaction chamber, the diamond substrate is placed above the workbench, and the plasma is formed in a spherical shape on the diamond substrate; the microwave is fed from below the reaction chamber and enters the reaction chamber through the quartz ring.

[0010] Preferably, the outer ring cooling chamber of the present utility model includes a lower end cover of the chamber, an outer wall of the chamber, an inner wall of the chamber, a coolant inlet conduit, an upper end cover of the chamber, and an outer microwave shielding ring. The outer microwave shielding ring is installed on the outer wall of the chamber. The coolant directly enters the bottom of the chamber through the coolant inlet conduit in the cavity. After the sealed cavity is filled with coolant, the coolant flows out from the outlet above the upper end cover of the chamber.

[0011] Preferably, the inner ring gas homogenizing chamber of the present utility model includes an inner ring chassis, an outer wall of the inner ring, an inner microwave shielding ring, an upper cover of the inner ring, a gas homogenizing pipe, a temperature measurement channel, and a coolant inlet and outlet. The inner microwave shielding ring is arranged on the outside of the outer wall of the inner ring and is in elastic close contact with the outer ring cooling chamber. The inner ring chassis matches the upper cover of the inner ring. The temperature measurement channel (36) is arranged at the center of the inner ring gas homogenizing chamber, and several evenly distributed gas homogenizing pipes are arranged on the inner ring gas homogenizing chamber.

[0012] Preferably, the process gas buffer chamber of the present utility model includes an upper sealing cover of the chamber body, a lower support plate, an upper support plate, a coolant inlet pipe, a temperature measurement pipe, and a coolant outlet pipe. The upper sealing cover of the chamber body is arranged at the top of the process gas buffer chamber. The coolant inlet pipe and the coolant outlet pipe are both two metal hollow pipes. One is fixed to the lower support plate, passes through the upper sealing cover of the chamber body, and enters the outer ring cooling chamber. The other is fixed to the upper support plate, passes through the upper sealing cover of the chamber body, and then is connected to the inner ring gas distribution chamber.

[0013] Preferably, the present utility model further includes a temperature measurement system. The temperature measurement system includes an infrared thermometer and an infrared thermometer bracket. The infrared thermometer is arranged on the infrared thermometer bracket. The infrared thermometer directly monitors the plasma through the quartz glass above the temperature measurement pipe and via the temperature measurement pipe.

[0014] Compared with the prior art, the present utility model has the following advantages and effects: The overall structure is reasonably designed, safe and reliable. When adopting the form of downward incident microwave, after the gas flow enters from above the chamber body, it can prevent the gas flow from impacting the diamond substrate; this device avoids the gas flow from impacting the diamond substrate and can improve the uniformity of the diamond. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic cross-sectional view of the overall structure of an embodiment of the present utility model.

[0016] Figure 2 It is a schematic structural view of the reaction chamber in an embodiment of the present utility model.

[0017] Figure 3 It is a schematic three-dimensional structural view of the outer ring cooling chamber in an embodiment of the present utility model.

[0018] Figure 4 It is a schematic cross-sectional view of the outer ring cooling chamber in an embodiment of the present utility model.

[0019] Figure 5 It is a schematic three-dimensional structural view of the inner ring gas distribution chamber in an embodiment of the present utility model.

[0020] Figure 6 It is a schematic cross-sectional view of the inner ring gas distribution chamber in an embodiment of the present utility model.

[0021] Figure 7 It is a schematic cross-sectional view of the process gas buffer chamber in an embodiment of the present utility model.

[0022] In the figure: reaction chamber 1, outer ring cooling chamber 2, inner ring gas distribution chamber 3, process gas buffer chamber 4, process gas inlet system 5, 6, temperature measurement system 7;

[0023] Reaction chamber 1: workbench 11, quartz ring 12, diamond substrate 13, plasma 14;

[0024] Outer ring cooling cavity 2: lower end cover 21 of the cavity, outer wall 22 of the cavity, inner wall 23 of the cavity, coolant inlet conduit 24, upper end cover 25 of the cavity, outer microwave shielding ring 26;

[0025] Inner ring gas distribution cavity 3: inner ring chassis 31, outer wall 32 of the inner ring, inner microwave shielding ring 33, upper cover 34 of the inner ring, gas distribution pipe 35, temperature measurement channel 36, coolant inlet and outlet 37;

[0026] Process gas buffer cavity 4: upper sealing cover 41 of the cavity, lower support plate 42, upper support plate 43, coolant inlet pipeline 44, temperature measurement pipeline 45, coolant outlet pipeline 46;

[0027] Temperature measurement system 7: infrared thermometer bracket 70, infrared thermometer 71. Specific implementation manner

[0028] The present utility model will be further described in detail below in conjunction with the accompanying drawings and through embodiments. The following embodiments are explanations of the present utility model and the present utility model is not limited to the following embodiments.

[0029] Embodiment

[0030] See Figures 1 to 7 , the large-size diamond growth MPCVD device for preventing air flow impact in this embodiment includes a reaction chamber 1, an outer ring cooling cavity 2, an inner ring gas distribution cavity 3, a process gas buffer cavity 4, a process gas inlet system 5, a coolant circulation pipeline 6 and a temperature measurement system 7.

[0031] The reaction chamber 1 in this embodiment includes a reaction chamber 1, a workbench 11, a quartz ring 12, a diamond substrate 13 and a plasma 14. The center of the reaction chamber 1 is a workbench 11 for diamond growth, and the diamond substrate 13 is placed above the workbench 11. Under the action of the microwave field, the microwave is fed into the reaction chamber 1 from below, passes through the quartz ring 12 and enters the reaction chamber 1. The process gas enters from the inner ring gas distribution cavity 3 above the reaction chamber 1 and is excited into a plasma state above the diamond substrate 13. The plasma 14 forms a spherical shape on the diamond substrate 13, and the substrate can be heated to a certain temperature by using the high temperature of the plasma 14.

[0032] The outer ring cooling cavity 2 in this embodiment is at the top of the outer ring of the reaction chamber 1 and is suspended at a certain height above the reaction chamber 1. Its upper part is connected to the process gas buffer cavity 4. The outer ring cooling cavity 2 mainly plays a role in isolating the high-speed process gas from the reaction chamber 1, and coolant is introduced into it, and at the same time plays a role in assisting in controlling the working temperature in the reaction chamber 1.

[0033] In this embodiment, the outer ring cooling cavity 2 includes a cavity lower end cover 21, a cavity outer wall 22, a cavity inner wall 23, a coolant inlet conduit 24, a cavity upper end cover 25, and an outer microwave shielding ring 26. The outer microwave shielding ring 26 is installed on the cavity outer wall 22 and is in elastic contact with the equipment cavity wall, which can be one or more circles, for preventing microwave leakage. All components are firmly combined by thermoforming technology to form a sealed cavity. The coolant directly enters the bottom of the cavity through the coolant inlet conduit 24 in the cavity. After the sealed cavity is filled with coolant, the coolant flows out from the outlet above the cavity upper end cover 25.

[0034] In this embodiment, the inner ring gas equalizing cavity 3 includes an inner ring bottom plate 31, an inner ring outer wall 32, an inner microwave shielding ring 33, an inner ring upper cover 34, gas equalizing pipes 35, a temperature measurement channel 36, and a coolant inlet and outlet 37. The inner ring gas equalizing cavity 3 is at the top center of the cavity of the reaction chamber 1 and hangs at a certain height directly above the reaction chamber 1. The inner ring gas equalizing cavity 3 isolates the reaction chamber 1 from the process gas buffer cavity 4. Between the two cavities, an inner microwave shielding ring 33 is arranged on the outside of the inner ring outer wall 32 and is in elastic and close contact with the outer ring cooling cavity 2, which can be one or more circles, for preventing microwave leakage. An annular groove is arranged on the inner ring bottom plate 31 and is welded integrally with the inner ring upper cover 34 to form a cavity for heat transfer of the coolant. A temperature measurement channel 36 is arranged at the center of the inner ring gas equalizing cavity 3, and the infrared thermometer 71 reads the temperature of the plasma cluster through the temperature measurement channel 36. Most importantly, a number of uniformly distributed gas equalizing pipes 35 are arranged on the inner ring gas equalizing cavity 3. After the process gas is buffered in the process gas buffer cavity 4, its speed has decreased, and then it flows out through the gas equalizing pipes 35 and enters the reaction chamber 1. The gas outlet is directly above the diamond substrate 13, and the dispersed gas does not directly blow on the diamond substrate 13 but is evenly dispersed in the reaction chamber 1.

[0035] In this embodiment, the process gas buffer cavity 4 includes a cavity upper sealing cover 41, a lower support plate 42, an upper support plate 43, a coolant inlet pipeline 44, a temperature measurement pipeline 45, and a coolant outlet pipeline 46. The top of the process gas buffer cavity 4 is the cavity upper sealing cover 41. Process gas inlet systems 5 are symmetrically arranged on both sides of the cavity upper sealing cover. The process gas enters the process gas buffer cavity 4 through a metal pipeline and an interface. After the process gas buffer cavity 4 is filled with the process gas, the speed of the gas flow becomes slower and more stable in the buffer cavity.

[0036] This embodiment includes a process gas inlet system 5. The process gas passes through the main inlet pipeline, and after passing through a tee, the metal channel is divided into two parts, enters the metal interface from the two side elbows, and passes through the central hole of the flange plate connected to the metal interface. The flange plate and the cavity upper sealing cover are fastened with screws, and an O-ring is set for sealing and a microwave shielding ring is set to ensure the gas sealing performance and microwave shielding function. The gas inlet diameter is set in a gradually increasing manner for gas flow buffering.

[0037] In the MPCVD device of this embodiment, to prevent the temperature of each cavity from being too high, the cavity wall is generally set in a hollow mode, and a coolant is introduced into the interior to cool the cavity. The coolant circulation pipeline 6 is divided into a coolant inlet pipeline 44 and a coolant outlet pipeline 46. The coolant inlet pipeline 44 consists of two metal hollow pipes. One is fixed to the lower support plate 42, passes through the upper sealing cover 41 of the cavity, and enters the outer ring cooling cavity 2. The other is fixed to the upper support plate 43, passes through the upper sealing cover 41 of the cavity, and then enters the inner ring gas distribution cavity 3. The coolant outlet pipeline 46 also consists of two metal hollow pipes. One is fixed to the lower support plate 42, passes through the upper sealing cover 41 of the cavity, and is connected to the outer ring cooling cavity 2. The other is fixed to the upper support plate 43, passes through the upper sealing cover 41 of the cavity, and then is connected to the inner ring gas distribution cavity 3.

[0038] In this embodiment, the temperature measurement system 7 includes an infrared thermometer bracket 70 and an infrared thermometer 71. The temperature at the position of the plasma cluster is monitored in real time by the infrared thermometer 71. The infrared thermometer 71 is set at the top of the device, and directly monitors the plasma cluster through the quartz glass above the temperature measurement pipeline 45 and via the temperature measurement pipeline 45.

[0039] The large-size diamond growth MPCVD device for preventing air flow impact in this embodiment solves the problems of large intake air impact force and uneven intake air in existing large-size MPCVD devices.

[0040] Through the above description, those skilled in the art can already implement it.

[0041] In addition, it should be noted that for the specific embodiments described in this specification, the shapes, names of their parts and components, etc. can be different. The above content described in this specification is only an example of the structure of the present invention. Any equivalent changes or simple changes made according to the structure, features and principles of the present invention concept are included in the protection scope of the present invention patent. Those skilled in the technical field to which the present invention belongs can make various modifications, supplements or use similar methods to replace the specific embodiments described, as long as they do not deviate from the structure of the present invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

Claims

1. A large-size diamond growth MPCVD device resistant to air flow impact, comprising a reaction chamber (1), an outer ring cooling chamber (2), an inner ring gas homogenizing chamber (3), a process gas buffer chamber (4), and a process gas inlet system (5), characterized in that: The outer ring cooling cavity (2) is arranged at the top of the outer ring of the reaction cavity (1). The upper part of the outer ring cooling cavity (2) is connected to the process gas buffer cavity (4). The inner ring gas distribution cavity (3) is arranged at the top of the center of the reaction cavity (1). The inner ring gas distribution cavity (3) isolates the reaction cavity (1) from the process gas buffer cavity (4). The process gas inlet systems (5) are symmetrically arranged on both sides at the top of the process gas buffer cavity (4). The reaction cavity (1) includes a workbench (11), a quartz ring (12), a diamond substrate (13) and a plasma (14). The workbench (11) is located at the center of the reaction cavity (1). The diamond substrate (13) is placed above the workbench (11). The plasma (14) is formed in a spherical shape on the diamond substrate (13). Microwaves are fed in from below the reaction cavity (1) and enter the reaction cavity (1) through the quartz ring (12).

2. The large-size diamond growth MPCVD device for preventing air flow impact according to claim 1, wherein: The outer ring cooling cavity (2) includes a cavity lower end cover (21), a cavity outer wall (22), a cavity inner wall (23), a coolant inlet conduit (24), a cavity upper end cover (25) and an outer microwave shielding ring (26). The outer microwave shielding ring (26) is installed on the cavity outer wall (22). The coolant directly enters the bottom of the cavity through the coolant inlet conduit (24) in the cavity until the sealed cavity is filled with the coolant, and then the coolant flows out from the outlet above the cavity upper end cover (25).

3. The large-size diamond growth MPCVD device for preventing air flow impact according to claim 1, characterized in that: The inner ring gas distribution cavity (3) includes an inner ring bottom plate (31), an inner ring outer wall (32), an inner microwave shielding ring (33), an inner ring upper cover (34), a gas distribution pipe (35), a temperature measurement channel (36) and a coolant inlet and outlet (37). The inner microwave shielding ring (33) is arranged on the outside of the inner ring outer wall (32) and is in elastic close contact with the outer ring cooling cavity (2). The inner ring bottom plate (31) matches the inner ring upper cover (34). The temperature measurement channel (36) is arranged at the center of the inner ring gas distribution cavity (3). A number of uniformly distributed gas distribution pipes (35) are arranged on the inner ring gas distribution cavity (3).

4. The large-size diamond growth MPCVD device for preventing air flow impact according to claim 1, wherein: The process gas buffer cavity (4) includes a cavity upper sealing cover (41), a lower support plate (42), an upper support plate (43), a coolant inlet pipeline (44), a temperature measurement pipeline (45) and a coolant outlet pipeline (46). The cavity upper sealing cover (41) is arranged at the top of the process gas buffer cavity (4). The coolant inlet pipeline (44) and the coolant outlet pipeline (46) are both two metal hollow pipes. One is fixed on the lower support plate (42), passes through the cavity upper sealing cover (41) and enters the outer ring cooling cavity (2). The other is fixed on the upper support plate (43), and after passing through the cavity upper sealing cover (41), it is connected to the inner ring gas distribution cavity (3).

5. The large-size diamond growth MPCVD device for preventing air flow impact according to claim 4, characterized in that: It further includes a temperature measurement system (7). The temperature measurement system (7) includes an infrared thermometer (71) and an infrared thermometer bracket (70). The infrared thermometer (71) is arranged on the infrared thermometer bracket (70). The infrared thermometer (71) directly monitors the plasma (14) through the quartz glass above the temperature measurement pipeline (45) and via the temperature measurement pipeline (45).

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