MPCVD system

Abstract

The utility model discloses an MPCVD system. The MPCVD system comprises a furnace body, a deposition table, a connecting rod, a microwave input device and a bias device, the furnace body is internally provided with a reaction cavity and comprises a bottom plate, an air inlet hole and an air outlet hole; the deposition table is positioned in the reaction cavity; the microwave input device comprises a microwave power supply and a microwave transmission module, the microwave power supply is located outside the furnace body, and the microwave transmission module is used for transmitting microwaves generated by the microwave power supply into the reaction cavity; the connecting rod penetrates through the furnace body; a first end of the connecting rod is connected with the deposition table; the bias device comprises a bias power supply and a lead-in wire, the bias power supply is located on the outer side of the furnace body, one end of the bias power supply is grounded, the other end of the bias power supply is connected with the first end of the lead-in wire, the lead-in wire penetrates through the hollow cavity of the connecting rod, and the second end of the lead-in wire is electrically connected with the deposition table. According to the MPCVD system, diamond bias pressure nucleation and deposition growth are integrated, the diamond deposition rate can be increased, and the effective deposition diameter of diamond can be increased.

Description

TECHNICAL FIELD

[0001] The utility model relates to diamond single crystal preparation field, especially a kind of MPCVD system. BACKGROUND

[0002] Diamond has extremely excellent thermal, electrical and other comprehensive performance, among which the most concerned is diamond ultra-wide band gap high temperature semiconductor application, because diamond not only has large band gap (5.47eV), high carrier mobility (electron 4500cm 2 / (V·S), hole 3800cm 2 / (V·S)), low dielectric constant, and extremely high thermal conductivity (2000W / (m·K)), strong radiation damage resistance, so it is expected to be used as high-performance semiconductor device working under high power, high frequency, high temperature or strong radiation conditions. Because the size and quality of artificial single crystal diamond cannot meet the application requirements of device field, to break this limitation, a variety of synthetic diamond methods are improved, including high temperature and high pressure method, hot filament chemical vapor deposition (HFCVD) method, microwave plasma chemical vapor deposition (MPCVD) method, etc., among which MPCVD method is widely concerned due to its high stability and high controllability, and is considered as the preferred method for preparing large-size high-quality diamond.

[0003] MPCVD method for synthesizing diamond is mainly divided into two ways: heteroepitaxy and homoepitaxy, wherein the size of diamond prepared by homoepitaxy is limited by the size and cost of seed crystal, and the method of heteroepitaxy is often used to prepare large-size diamond. In order to improve the nucleation density of heteroepitaxy substrate and improve the quality of diamond crystal, the method of applying bias voltage is often used to realize BEN (bias voltage enhanced nucleation) process. The existing MPCVD mainly has two microwave operating frequencies of 2.45GHz and 915MHz. The 2.45GHz MPCVD equipment technology is more mature, and the bias voltage is applied on the equipment to obtain more results, but due to the wavelength limitation, the effective deposition diameter of diamond of 2.45GHz MPCVD equipment is only 61mm, which is difficult to meet the increasing size requirement, therefore, it is extremely necessary to develop 915MHz MPCVD equipment. However, the 915MHz MPCVD equipment is mainly based on microwave growth, and does not introduce bias voltage, so it is difficult to realize large-area and high-density diamond nucleation, and the existing MPCVD equipment bias nucleation and growth system mostly adopts separate method for diamond preparation, that is, nucleation and growth process belong to two devices, and the operation steps are complicated, and there is the risk of substrate contamination. UTILITY MODEL CONTENT

[0004] The utility model provides a kind of MPCVD system, above-mentioned MPCVD system integrates diamond bias nucleation and deposition growth, can form large area, high density diamond nucleation, improve diamond deposition rate and diamond effective deposition diameter, can realize including 8 inch in large size heteroepitaxial single crystal diamond growth.

[0005] To achieve the above object, the utility model provides the following technical scheme:

[0006] A kind of MPCVD system, including furnace body, deposition table, connecting rod, microwave input device and bias device;

[0007] The furnace body has reaction cavity inside, and the furnace body includes bottom plate, gas inlet hole and gas outlet hole;

[0008] The deposition table is located in reaction cavity, and the side of the deposition table away from the bottom plate is used to place substrate;

[0009] The microwave input device includes microwave power supply and microwave transmission module, the microwave power supply is located outside the furnace body, the microwave transmission module is connected with the microwave power supply and the deposition table, and the microwave transmission module is used to transmit the microwave generated by the microwave power supply into the reaction cavity;

[0010] The connecting rod penetrates the furnace body, the first end of the connecting rod is connected with the deposition table, and the connecting pipe has hollow cavity;

[0011] The bias device includes bias power supply and lead-in wire, the bias power supply is located outside the furnace body, one end of the bias power supply is grounded, the other end of the bias lead is connected with the first end of the lead-in wire, the lead-in wire passes through the hollow cavity of the connecting rod, and the second end of the lead-in wire is electrically connected with the deposition table.

[0012] Optionally, the frequency of the microwave generated by the microwave power supply is 915MHz.

[0013] Optionally, the bias power supply uses pulse voltage of 1V to 800V.

[0014] Optionally, the bias device further includes bias ring, the bias ring is located in the reaction cavity and on the side of the deposition table away from the bottom plate, the bias ring is connected with the bottom plate through connecting wire and grounded.

[0015] Optionally, it further includes support ring between the bottom plate and the deposition table, and the support ring is used to support the deposition table.

[0016] Optionally, the deposition table includes fixed part and movable part.

[0017] The movable part is located on the side of the fixed part away from the support ring, and the side of the movable part away from the fixed part is used to place the substrate.

[0018] The connecting rod passes through the base plate and the fixed part. The first end of the connecting rod is fixedly connected to the movable part, and the center line of the connecting rod coincides with the center line of the movable part. The connecting rod is used to drive the movable part to move.

[0019] It also includes a lifting motor base and a rotating motor base located on the outside of the furnace body. The lifting motor base is connected to the second end of the connecting rod and is used to drive the connecting rod to move along the extension direction of the lifting rod. The rotating motor base is connected to the second end of the connecting rod and is used to drive the connecting rod to rotate along its own center line.

[0020] Optionally, the movable part includes a cooling section, a high thermal conductivity insulating ring, and a conductive section;

[0021] The cooling section is embedded in the fixed part, and the cooling section is connected to the connecting rod;

[0022] The high thermal conductivity insulating ring is located on the side of the cooling section away from the fixed part;

[0023] The conductive part is located on the side of the high thermal conductivity insulating ring away from the cooling part. The conductive part is connected to the end of the lead wire in the connecting rod. The side of the conductive part away from the high thermal conductivity insulating ring is used to place the substrate.

[0024] Optionally, the middle region of the cooling section has a connecting channel;

[0025] The biasing device further includes a biasing adapter and a biasing lead located in the wiring channel. The biasing adapter is embedded in the wiring channel. A first end of the biasing adapter is connected to the lead wire, and a second end of the biasing adapter is connected to the conductive part through the biasing lead.

[0026] Optionally, the bias adapter includes a clamping screw, a metal adapter bar, a bias inlet connector, a metal sleeve, and a ceramic sleeve;

[0027] The first end of the metal adapter rod is connected to the lead wire via the clamping screw, and the second end of the metal adapter rod is connected to the bias lead wire via the bias lead connector;

[0028] The metal sleeve is fitted over the outside of the clamping screw and the metal adapter bar;

[0029] The ceramic sleeve is fitted over the outside of the metal sleeve, and the outer wall of the ceramic sleeve is fixedly connected to the inner wall of the connecting channel.

[0030] Optionally, the conductive part includes a conductive substrate, a conductive support plate, and a conductive cover plate;

[0031] The conductive substrate is located on the side of the high thermal conductivity insulating ring away from the cooling part, and the conductive substrate is electrically connected to the bias lead;

[0032] The conductive tray is located on the side of the conductive substrate away from the high thermal conductivity insulating ring, and the side of the conductive tray away from the conductive substrate is used to place the substrate.

[0033] The conductive cover plate is located on the side of the conductive substrate away from the high thermal conductivity insulating ring, and the middle region of the conductive cover plate has an opening, with the conductive support plate located within the opening.

[0034] Optionally, the fixing part has a first water-cooling channel, the cooling part has a second water-cooling channel, and the furnace body has a third water-cooling channel;

[0035] It also includes a water cooling device, which is connected to the first water cooling channel, the second water cooling channel and the third water cooling channel, and is used to provide cooling water to the first water cooling channel, the second water cooling channel and the third water cooling channel.

[0036] Optionally, the microwave transmission module includes a microwave tuner, a rectangular waveguide, a coaxial waveguide, and a microwave plug;

[0037] The input terminal of the microwave tuner is connected to the microwave power supply, and the output terminal of the microwave tuner is connected to the first end of the rectangular waveguide.

[0038] The coaxial waveguide extends through the base plate and the support ring. The extension direction of the coaxial waveguide is perpendicular to the extension direction of the rectangular waveguide. The first end of the coaxial waveguide is connected to the second end of the rectangular waveguide, and the second end of the coaxial waveguide is connected to the fixed part. The coaxial waveguide includes a first part and a second part. The first part is located outside the reaction cavity and is made of metal. The second part is located inside the reaction cavity and is made of quartz.

[0039] The microwave plug is located on the side of the coaxial waveguide away from the deposition stage;

[0040] The support ring is made of quartz.

[0041] Optionally, the connecting rod passes through the microwave plug and the coaxial waveguide, and the centerline of the connecting rod coincides with the centerline of the coaxial waveguide;

[0042] The inner wall of the coaxial waveguide, the inner wall of the fixed part, and the outer wall of the connecting rod cooperate to form a first temperature-regulating cavity.

[0043] The movable part has a second temperature-regulating cavity and a gas channel, and the second temperature-regulating cavity is connected to the first temperature-regulating cavity through the gas channel.

[0044] Optionally, in the movable portion, the conductive part, the high thermal conductivity insulating ring, and the cooling part cooperate to form the second temperature regulating cavity, and the cooling part has the gas channel;

[0045] The connection channel is connected to the second temperature control cavity;

[0046] The bias lead is electrically connected to the middle region of the conductive part within the second temperature-regulating cavity; or...

[0047] The bias lead passes through the cooling section and the edge region of the high thermal conductivity insulating ring and the conductive section.

[0048] Optionally, the microwave power supply has a power of 100kW.

[0049] Optionally, it also includes a bell jar located within the reaction chamber, the edge of which is sealed to the base plate;

[0050] The air inlet and the air outlet are located on the base plate;

[0051] The deposition stage, bias ring, support ring, air inlet, and air outlet are located inside the bell jar.

[0052] This invention provides an MPCVD system comprising a furnace body, a deposition stage, a connecting rod, a microwave input device, and a bias device. The furnace body's inlet allows for the input of reactive gas into the reaction chamber, while the outlet allows for the output of reactive gas from the reaction chamber. The deposition stage is located within the reaction chamber, and a substrate can be placed on the side of the deposition stage facing away from the furnace body. The microwave input device provides microwaves to the reaction chamber, enabling diamond growth on the substrate. The bias device's bias power supply is electrically connected to the deposition stage via a lead wire within the connecting rod, applying a bias voltage to the substrate on the deposition stage to enhance nucleation and thus form large-area, high-density diamond nuclei on the substrate. In this MPCVD system, the bias device enables the formation of large-area, high-density diamond nuclei, increasing the diamond deposition rate and effective diamond deposition diameter. It allows for the growth of large-size heteroepitaxial single-crystal diamonds, including 8-inch specimens. Furthermore, the integration of diamond bias nucleation and deposition growth simplifies the operation process. After diamond nucleation, growth can be directly performed in the same equipment, reducing interference from changes in the chamber environment and substrate transfer on the growth structure. Attached Figure Description

[0053] Figure 1 A schematic diagram of the structure of an MPCVD system provided in an embodiment of this utility model;

[0054] Figure 2 A schematic diagram of the structure of a movable part provided in an embodiment of this utility model;

[0055] Figure 3 A schematic diagram of the structure of a movable part provided in an embodiment of this utility model;

[0056] Figure 4 This is a schematic diagram of the structure of a bias adapter provided in an embodiment of the present utility model.

[0057] icon:

[0058] 1-Furnace body; 11-Base plate; 101-Air inlet; 102-Air outlet; 2-Deposition stage; 21-Fixed part; 211-First water-cooling channel; 22-Modible part; 221-Cooling part; 222-High thermal conductivity insulating ring; 223-Conductive part; 2231-Conductive substrate; 2232-Conductive support plate; 2233-Conductive cover plate; 2201-Connection channel; 2202-Second water-cooling channel; 2203-Gas channel; 23-Substrate; 201-Support ring; 31-Microwave power supply; 32-Microwave modulator; 33 - Rectangular waveguide; 34 Coaxial waveguide; 35 Microwave plug; 4 Connecting rod; 51 Bias power supply; 52 Lead wire; 53 Bias ring; 54 Bias adapter; 541 Clamping screw; 542 Metal adapter rod; 543 Bias lead connector; 544 Metal sleeve; 545 Ceramic sleeve; 55 Bias lead wire; A First temperature control cavity; B Second temperature control cavity; 61 Water cooling device; 62 Temperature measuring device; 7 Bell jar; 71 Sealing gasket; 81 Gas transmission device; 82 Vacuum device; 9 Electrical control module. Detailed Implementation

[0059] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0060] Please refer to Figure 1 , Figure 2 and Figure 3 This utility model provides an MPCVD system, including a furnace body 1, a deposition stage 2, a connecting rod, a microwave input device, and a bias device;

[0061] The furnace body 1 has a reaction chamber inside, and the furnace body 1 includes a bottom plate 11, an air inlet 101 and an air outlet 102;

[0062] The deposition stage 2 is located inside the reaction chamber, and the side of the deposition stage 2 away from the base plate 11 is used to place the substrate 23;

[0063] The microwave input device includes a microwave power supply 31 and a microwave transmission module. The microwave power supply 31 is located outside the furnace body 1, and the microwave transmission module is connected to the microwave power supply 31 and the deposition stage 2. The microwave transmission module is used to transmit the microwaves generated by the microwave power supply 31 into the reaction chamber.

[0064] The connecting rod 4 passes through the furnace body 1, and the first end of the connecting rod 4 is connected to the deposition stage 2. The connecting rod has a hollow cavity.

[0065] The biasing device includes a biasing power supply 51 and a lead wire 52. The biasing power supply 51 is located outside the furnace body 1. The first electrode of the biasing power supply 51 is grounded. The lead wire 52 passes through the hollow cavity of the connecting rod 4. The first end of the lead wire 52 is connected to the second electrode of the biasing power supply 51, and the second end of the lead wire 52 is electrically connected to the deposition stage 2.

[0066] The MPCVD system provided in this embodiment includes a furnace body 1, a deposition stage 2, a connecting rod 4, a microwave input device, and a bias device. The furnace body 1 can input reaction gas into the reaction chamber through the gas inlet 101 and output reaction gas from the reaction chamber through the gas outlet 102. The deposition stage 2 is located inside the reaction chamber, and a substrate 23 can be placed on the side of the deposition stage 2 away from the furnace body 1. The microwave input device can provide microwaves to the reaction chamber to grow diamond on the substrate 23. The bias power supply 51 of the bias device is electrically connected to the deposition stage 2 through the lead wire 52 in the connecting rod 4, which can apply bias voltage to the substrate 23 on the deposition stage 2 to enhance nucleation and thus form a large area and high density of diamond nuclei on the substrate 23. In the aforementioned MPCVD system, a bias voltage device is installed, which can form large-area, high-density diamond nuclei, improve the diamond deposition rate and the effective diamond deposition diameter, and enable the growth of large-size heteroepitaxial single-crystal diamonds, including 8 inches. Furthermore, the integration of diamond bias voltage nucleation and deposition growth simplifies the operation process. After diamond nucleation is completed, it can be grown directly in the same equipment, reducing the interference of factors such as changes in the chamber environment and substrate transfer on the growth structure.

[0067] Specifically, the positive terminal of the aforementioned bias power supply 51 can be grounded, and the negative terminal of the bias power supply 51 can be connected to the lead-in wire 52.

[0068] Specifically, the microwave frequency generated by the aforementioned microwave power supply 31 can be 915MHz. That is, the MPCVD system provided in this embodiment can achieve the design of adding a bias device to a 915MHz MPCVD system, thus achieving high-density, large-size bias nucleation. The microwave input device provides 915MHz microwaves to the reaction chamber, which can excite the reactive gas and generate a large-area, high-power-density plasma sphere, thereby increasing the diamond deposition area and growth rate.

[0069] In this embodiment of the invention, the bias power supply 51 can use a pulse voltage ranging from 1V to 800V.

[0070] In the prior art, bias systems mostly use DC power to apply bias voltage. During the bias period, charge accumulates on the surface of substrate 23, and once discharge arcing occurs, it will damage the surface of substrate 23. In this embodiment of the present invention, by using pulse voltage, the charge on the surface of substrate 23 can be neutralized during the pulse gap, so as to protect the surface of substrate 23.

[0071] In this embodiment of the present invention, the biasing device may further include a biasing ring 53, which may be located in the reaction chamber and on the side of the deposition stage 2 away from the base plate 11. The biasing ring 53 is connected to the base plate 11 through a connecting line and is grounded.

[0072] Specifically, in the MPCVD system described above, the bias ring 53 can be a molybdenum mesh.

[0073] Specifically, in the MPCVD system described above, the substrate 23 is placed on the deposition stage 2, and the bias ring 53 can be set above the substrate 23. The bias ring 53 can act as a current loop, reduce the accumulation of charge on the surface of the substrate 23 during the biasing process, avoid arcing damage on the surface of the substrate 23, and allow the ion beam to be better controlled, resulting in a denser nucleation density.

[0074] In this embodiment of the invention, the power of the microwave power supply 31 can be 100kW.

[0075] In existing technologies, most 915MHz MPCVD equipment operates at power levels between 30kW and 50kW. This low excitation power results in low plasma sphere power density and slow growth rates. High power and low cavity pressure are crucial conditions for preparing large-area diamonds. In this embodiment, a 100kW microwave power supply 31 is used, which can generate microwave plasma spheres with higher power density and larger effective deposition area, thereby increasing the diamond growth rate and effective deposition area within the reaction chamber.

[0076] In this embodiment of the present invention, the MPCVD system further includes a support ring 201 located between the base plate 11 and the deposition stage 2, the support ring 201 being used to support the deposition stage 2.

[0077] Specifically, the support ring 201 can be made of quartz.

[0078] In this embodiment of the present invention, the deposition stage 2 may include a fixed part 21 and a movable part 22;

[0079] The movable part 22 can be located on the side of the fixed part 21 away from the support ring 201, and the side of the movable part 22 away from the fixed part 21 is used to place the substrate 23.

[0080] The connecting rod 4 can pass through the base plate 11 and the fixed part 21. The first end of the connecting rod 4 is fixedly connected to the movable part 22, and the center line of the connecting rod 4 coincides with the center line of the movable part 22. The connecting rod 4 is used to drive the movable part to move.

[0081] The aforementioned MPCVD system may also include a lifting motor base M1 and a rotary motor base M2 located outside the furnace body 1. The lifting motor base M1 is connected to the second end of the connecting rod 4 and is used to drive the connecting rod 4 to move along the extension direction of the lifting rod. The rotary motor base M2 is connected to the second end of the connecting rod 4 and is used to drive the connecting rod 4 to rotate along its own centerline.

[0082] In the existing technology, the deposition stage 2 of most 915MHz MPCVD equipment is not adjustable, which makes it difficult to ensure the uniformity of growth when growing large-area diamonds. Furthermore, as the growth thickness increases, the distribution of plasma spheres changes, making it difficult to maintain a stable growth temperature and further deteriorating the growth conditions.

[0083] In the MPCVD system provided by this utility model embodiment, the lifting motor base M1 can drive the movable part 22 of the deposition stage 2 to rise along the extension direction of the connecting rod 4 via the connecting rod 4, while the rotating motor base M2 can drive the movable part 22 of the deposition stage 2 to rotate along the center line of the connecting rod 4 via the connecting rod 4. This can effectively ensure the uniformity of diamond growth. Furthermore, by lifting the deposition stage 2 to adjust the relative position between the substrate 23 surface and the plasma ball, the optimal deposition position with the most uniform plasma ball density can be selected, which is beneficial to improving the deposition quality. It can also avoid temperature runaway caused by the increase in growth thickness, regulate the temperature of the substrate 23, and ensure the stability of the growth temperature.

[0084] Specifically, in this embodiment of the present invention, the lead wire 52 is located in the hollow cavity of the connecting rod 4, which allows the lead wire 52 to be coaxially sleeved with the connecting rod 4. The connecting rod 4 can be hidden below the deposition stage 2, so as to introduce the bias voltage onto the substrate 23, which facilitates the introduction of the bias voltage.

[0085] Specifically, the orthogonal projection of the bias ring 53 onto the deposition stage 2 can cover the movable part 22, ensuring the effectiveness of the bias ring 53.

[0086] In this embodiment of the utility model, such as Figure 2 and Figure 3 As shown, the movable part 22 may include a cooling part 221, a high thermal conductivity insulating ring 222, and a conductive part 223;

[0087] The cooling section 221 is embedded in the fixing section 21 and is connected to the connecting rod 4. The high thermal conductivity insulating ring 222 is located on the side of the cooling section 221 away from the fixing section 21. The conductive section 223 is located on the side of the high thermal conductivity insulating ring 222 away from the cooling section 221 and is connected to the end of the lead wire 52 in the connecting rod 4. The side of the conductive section 223 away from the high thermal conductivity insulating ring 222 is used to place the substrate 23.

[0088] In the MPCVD system described above, the cooling section 221 and the conductive section 223 of the movable part 22 are insulated from each other by a high thermal conductivity insulating ring 222. The connecting rod 4 can be fixedly connected to the cooling section 221 in the movable part 22. The lead wire 52 inside the connecting rod 4 is electrically connected to the conductive section 223 in the movable part 22. The conductive section 223 can transfer the bias voltage to the substrate 23, thereby applying a bias voltage to the substrate 23.

[0089] In this embodiment of the present invention, the middle region of the cooling section 221 may have a connecting channel 2201;

[0090] The aforementioned biasing device also includes a biasing adapter 54 and a biasing lead 55 located in the wiring channel 2201. The biasing adapter 54 is embedded in the wiring channel 2201. The first end of the biasing adapter 54 is connected to the lead wire 52, and the second end of the biasing adapter 54 is connected to the conductive part 223 through the biasing lead 55.

[0091] In the MPCVD system described above, the lead wire 52 inside the connecting rod 4 can be electrically connected to the bias lead 55 through the bias adapter 54 on the cooling part 221. The bias lead 55 then introduces the bias to the conductive part 223. In this way, the bias can be introduced into the substrate 23 while the bias lead 55 is hidden. In addition, the bias applied to the substrate 23 is not affected during the rotation of the movable part 22. The structure is simple and easy to implement.

[0092] Specifically, such as Figure 4 As shown, the bias adapter 54 may include a clamping screw 541, a metal adapter bar 542, a bias inlet connector 543, a metal sleeve 544, and a ceramic sleeve 545.

[0093] The first end of the metal adapter rod 542 is connected to the lead wire 52 via a clamping screw 541, and the second end of the metal adapter rod 542 is connected to the bias lead wire 55 via a bias lead connector 543. The metal sleeve 544 is fitted over the outside of the clamping screw 541 and the metal adapter rod. The ceramic sleeve 545 is fitted over the outside of the metal sleeve 544, and the outer wall of the ceramic sleeve 545 is fixedly connected to the inner wall of the wiring channel 2201.

[0094] In the aforementioned bias adapter 54, the clamping screw 541, the metal adapter rod 542, the bias introduction connector 543, and the metal sleeve 544 can have a conductive function, so as to introduce the bias voltage on the lead wire 52 to the conductive part 223, and then introduce the bias voltage to the substrate 23 through the conductive part 223. The ceramic sleeve 545 can make the metal sleeve 544 insulated from the cooling part 221, thus preventing the bias voltage from being applied to the cooling part 221.

[0095] In this embodiment of the utility model, such as Figure 2 and Figure 3 As shown, the conductive part 223 may include a conductive substrate 2231, a conductive support plate 2232, and a conductive cover plate 2233. The conductive substrate 2231 is located on the side of the high thermal conductivity insulating ring 222 away from the cooling part 221, and the conductive substrate 2231 is electrically connected to the bias lead 55. The conductive support plate 2232 is located on the side of the conductive substrate 2231 away from the high thermal conductivity insulating ring 222, and the side of the conductive support plate 2232 away from the conductive substrate 2231 is used to place the substrate 23. The conductive cover plate 2233 is located on the side of the conductive substrate 2231 away from the high thermal conductivity insulating ring 222, and the middle region of the conductive cover plate 2231 has an opening, and the conductive support plate 2232 is located in the opening.

[0096] In the aforementioned conductive part 223, the conductive substrate 2231 can introduce the bias voltage transmitted by the bias lead 55 to the conductive support plate 2232, and the conductive support plate 2232 can then introduce the bias voltage to the substrate 23, thus ensuring that the bias voltage is applied to the substrate 23.

[0097] Specifically, the materials of the conductive substrate 2231, conductive support plate 2232 and conductive cover plate 2233 can be metallic molybdenum or other conductive materials. There are no restrictions here, and it depends on the actual situation.

[0098] Specifically, the cooling section 221 can be connected to the high thermal conductivity insulating ring 222 by screws. The high thermal conductivity insulating ring 222 can be connected to the conductive substrate 2231 by screws.

[0099] In this embodiment of the utility model, the fixing part 21 has a first water cooling channel 211, the cooling part 221 has a second water cooling channel 2202, and the furnace body 1 has a third water cooling channel.

[0100] In the aforementioned MPCVD system, such as Figure 1 As shown, it also includes a water cooling device 61, which is connected to the first water cooling channel 211, the second water cooling channel 2202 and the third water cooling channel. The water cooling device 61 is used to provide cooling water to the first water cooling channel 211, the second water cooling channel 2202 and the third water cooling channel.

[0101] Specifically, the water cooling device 61 is connected to the first water cooling channel 211 and provides cooling water to the first water cooling channel 211, which can reduce the temperature of the fixed part 21 and the support ring 201 of the deposition stage 2; the water cooling device 61 is connected to the second water cooling channel 2202 and provides cooling water to the second water cooling channel 2202, which can dissipate heat from the substrate 23; the water cooling device is connected to the third water cooling channel and provides cooling water to the third water cooling channel, which can dissipate heat from the reaction chamber.

[0102] In this embodiment of the utility model, such as Figure 1 As shown, the microwave transmission module may include a microwave tuner 32, a rectangular waveguide 33, a coaxial waveguide 34, and a microwave plug 35.

[0103] The microwave tuner 32 has its input end connected to the microwave power supply 31 and its output end connected to the first end of the rectangular waveguide 33. The coaxial waveguide 34 passes through the base plate 11 and the support ring 201. The extension direction of the coaxial waveguide 34 is perpendicular to the extension direction of the rectangular waveguide 33. The first end of the coaxial waveguide 34 is connected to the second end of the rectangular waveguide 33, and the second end of the coaxial waveguide 34 is connected to the fixed part 21. The coaxial waveguide 34 includes a first part and a second part. The first part is located outside the reaction cavity and is made of metal. The second part is located inside the reaction cavity and is made of quartz. The microwave plug is located on the side of the coaxial waveguide 34 away from the deposition stage 2.

[0104] In the aforementioned MPCVD system, the microwave tuner 32 can be used to adjust the reflected power of the microwaves emitted by the microwave power supply 31. Through the cooperation of the microwave tuner 32, the rectangular waveguide 33, and the first part of the coaxial waveguide 34, the microwaves generated by the microwave power supply 31 can be fed into the reaction cavity from the bottom plate 11 of the furnace body 1 according to a preset path. The second part of the coaxial waveguide 34 and the support ring 201 allow the microwaves to pass through, thereby enabling the microwaves to be transmitted into the reaction cavity. The deposition stage 2 can couple the microwaves, and the microwave plug 35 can block the microwaves on the coaxial waveguide 34 from being transmitted toward the side away from the deposition stage 2.

[0105] In this embodiment of the utility model, such as Figure 2 and Figure 3As shown, the connecting rod 4 passes through the microwave plug 35 and the coaxial waveguide 34, and the center line of the connecting rod 4 coincides with the center line of the coaxial waveguide 34; the inner wall of the coaxial waveguide 34, the inner wall of the fixed part 21 and the outer wall of the connecting rod 4 cooperate to form a first temperature-regulating cavity A; the movable part 22 has a second temperature-regulating cavity B and a gas channel 2203, and the second temperature-regulating cavity B and the first temperature-regulating cavity A are connected through the gas channel 2203.

[0106] In the MPCVD system described above, the first temperature control cavity A and the second temperature control cavity B can form a temperature control module. The end of the first temperature control cavity A located away from the furnace body 1 can be sealed. The first temperature control cavity A can be connected to a vacuum pump. By controlling the flow rate of the gas in the first temperature control cavity A and the second temperature control cavity B, the thermal conductivity of the movable part 22 can be changed, thereby enabling fine adjustment of the temperature on the substrate 23.

[0107] Maintaining stable growth temperature is crucial during diamond growth. Existing equipment often addresses temperature fluctuations by altering microwave input power or cavity pressure. However, temperature and cavity pressure have a specific matching relationship and directly affect the state of the plasma sphere within the cavity. Therefore, this adjustment method is unsuitable for scenarios requiring extremely high plasma stability. In this embodiment, by setting up a first temperature-regulating cavity A and a second temperature-regulating cavity B, flexible temperature control is achieved without changing the input power or the pressure within the reaction cavity. This ensures the stability of the power density and uniformity of the microwave plasma sphere, facilitating the growth of large-size, high-quality diamonds.

[0108] In this embodiment of the present invention, in the movable part 22, the conductive part 223, the high thermal conductivity insulating ring 222, and the cooling part 221 cooperate to form a second temperature regulating cavity B. The cooling part 221 has a gas channel 2203. The wiring channel 2201 can be connected to the second temperature regulating cavity B. The bias lead 55 is electrically connected to the middle region of the conductive part 223 in the second temperature regulating cavity B, or the bias lead 55 passes through the cooling part 221 and the high thermal conductivity insulating ring 222 and connects to the edge region of the conductive part 223.

[0109] In the MPCVD system described above, the bias lead 55 can be routed and hidden inside the movable part 22 to prevent damage to the bias lead 55 and improve the stability of the bias introduction.

[0110] Specifically, the gas channel 2203 can be symmetrically arranged on both sides of the connecting channel 2201.

[0111] In this embodiment of the utility model, such as Figure 1As shown, the MPCVD system also includes a bell jar 7 located inside the reaction chamber, with the edge of the bell jar 7 sealed to the base plate 11; wherein, the air inlet 101 and the air outlet 102 are located on the base plate 11; the deposition stage 2, the bias ring 53, the support ring 201, the air inlet 101 and the air outlet 102 are located inside the bell jar 7.

[0112] In the existing technology, the 915MHz MPCVD equipment has a large chamber area, which can be used to prepare large-sized diamonds. However, this also brings the problem that some derivatives after growth have a large distribution area and are difficult to clean. In particular, when specific impurity gases are introduced for doping, the memory effect of the chamber will contaminate the chamber, making it difficult to grow high-quality intrinsic diamonds in the future.

[0113] In this embodiment of the invention, a bell jar 7 is provided inside the reaction chamber, which can ensure the cleanliness of the chamber, confine the carbon derivatives during the growth process inside the bell jar 7, and effectively suppress the memory effect generated in the chamber during the doping process, thus facilitating the subsequent cleaning of the chamber.

[0114] Specifically, the edge of the bell jar 7 can be sealed to the base plate 11 by means of a sealing gasket 71.

[0115] In this embodiment of the utility model, such as Figure 1 As shown, the above-mentioned MPCVD also includes a gas transfer device 81 and a vacuum device 82;

[0116] The gas transmission device 81 is connected to the gas inlet 101, and the vacuum device 82 is connected to the gas outlet 102. The gas transmission system can provide the reaction chamber with the raw material gases for microwave plasma excitation and diamond chemical vapor deposition, such as H2, CH4, O2, dopant sources, N2 / H2, etc.; the vacuum system can ensure that the reaction chamber maintains a controllable vacuum level. The cooperation between the gas transmission device 81 and the vacuum system can keep the chamber pressure within the required range, ensuring a stable diamond growth environment.

[0117] In this embodiment of the present invention, the MPCVD also includes a temperature measuring device 62. The temperature measuring device 62 can be located outside the furnace body 1. The furnace body 1 has a window that is opposite to the substrate 23. The temperature measuring device 62 is opposite to the window and is used to measure the temperature of the substrate 23, so as to better control the process of nucleation and growth.

[0118] In this embodiment of the present invention, the MPCVD also includes an electronic control device. The electronic control device can be connected to the microwave power supply 31, the bias power supply 51, the gas transmission device 81, the vacuum device 82, the temperature measuring device 62, the water cooling device 61, the lifting motor base M1, the rotary motor base M2, and the air pump, etc. The electronic control device can be used to control the microwave power supply 31 to generate microwaves, the bias power supply 51 to output bias voltage, the gas transmission device 81 to deliver gas flow rate, and the vacuum device 82 to pump air flow rate, etc.

[0119] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this utility model without departing from the spirit and scope of this utility model. Therefore, if these modifications and variations of this utility model fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An MPCVD system, characterized in that, Includes furnace body, deposition stage, connecting rod, microwave input device and bias device; The furnace body has a reaction chamber inside, and the furnace body includes a bottom plate, an air inlet, and an air outlet. The deposition stage is located inside the reaction chamber, and the side of the deposition stage facing away from the base plate is used to place the substrate; The microwave input device includes a microwave power supply and a microwave transmission module. The microwave power supply is located outside the furnace body, and the microwave transmission module is connected to the microwave power supply and the deposition stage. The microwave transmission module is used to transmit the microwaves generated by the microwave power supply into the reaction chamber. The connecting rod passes through the furnace body, and the first end of the connecting rod is connected to the deposition stage. The connecting rod has a hollow cavity. The biasing device includes a biasing power supply and a lead wire. The biasing power supply is located outside the furnace body. One end of the biasing power supply is grounded, and the other end of the biasing power supply is connected to the first end of the lead wire. The lead wire passes through the hollow cavity of the connecting rod, and the second end of the lead wire is electrically connected to the deposition stage.

2. The MPCVD system according to claim 1, characterized in that, The microwave power supply generates microwaves with a frequency of 915MHz.

3. The MPCVD system according to claim 1, characterized in that, The bias power supply uses a pulse voltage ranging from 1V to 800V.

4. The MPCVD system according to claim 1, characterized in that, The biasing device further includes a bias ring located inside the reaction chamber and on the side of the deposition stage away from the base plate. The bias ring is connected to the base plate via a connecting line and is grounded.

5. The MPCVD system according to claim 4, characterized in that, It also includes a support ring located between the base plate and the deposition stage, the support ring being used to support the deposition stage.

6. The MPCVD system according to claim 5, characterized in that, The deposition stage includes a fixed part and a movable part; The movable part is located on the side of the fixed part away from the support ring, and the side of the movable part away from the fixed part is used to place the substrate. The connecting rod passes through the base plate and the fixed part. The first end of the connecting rod is fixedly connected to the movable part, and the center line of the connecting rod coincides with the center line of the movable part. The connecting rod is used to drive the movable part to move. It also includes a lifting motor base and a rotating motor base located on the outside of the furnace body. The lifting motor base is connected to the second end of the connecting rod and is used to drive the connecting rod to move along the extension direction of the connecting rod. The rotating motor base is connected to the second end of the connecting rod and is used to drive the connecting rod to rotate along its own center line.

7. The MPCVD system according to claim 6, characterized in that, The movable part includes a cooling section, a high thermal conductivity insulating ring, and a conductive section. The cooling section is embedded in the fixed part, and the cooling section is connected to the connecting rod; The high thermal conductivity insulating ring is located on the side of the cooling section away from the fixed part; The conductive part is located on the side of the high thermal conductivity insulating ring away from the cooling part. The conductive part is connected to the end of the lead wire in the connecting rod. The side of the conductive part away from the high thermal conductivity insulating ring is used to place the substrate.

8. The MPCVD system according to claim 7, characterized in that, The middle area of ​​the cooling section has a connecting channel; The biasing device further includes a biasing adapter and a biasing lead located in the wiring channel. The biasing adapter is embedded in the wiring channel. A first end of the biasing adapter is connected to the lead wire, and a second end of the biasing adapter is connected to the conductive part through the biasing lead.

9. The MPCVD system according to claim 8, characterized in that, The bias adapter includes a clamping screw, a metal adapter rod, a bias inlet connector, a metal sleeve, and a ceramic sleeve. The first end of the metal adapter rod is connected to the lead wire via the clamping screw, and the second end of the metal adapter rod is connected to the bias lead wire via the bias lead connector; The metal sleeve is fitted over the outside of the clamping screw and the metal adapter bar; The ceramic sleeve is fitted over the outside of the metal sleeve, and the outer wall of the ceramic sleeve is fixedly connected to the inner wall of the connecting channel.

10. The MPCVD system according to claim 8, characterized in that, The conductive part includes a conductive substrate, a conductive support plate, and a conductive cover plate; The conductive substrate is located on the side of the high thermal conductivity insulating ring away from the cooling part, and the conductive substrate is electrically connected to the bias lead; The conductive tray is located on the side of the conductive substrate away from the high thermal conductivity insulating ring, and the side of the conductive tray away from the conductive substrate is used to place the substrate. The conductive cover plate is located on the side of the conductive substrate away from the high thermal conductivity insulating ring, and the middle region of the conductive cover plate has an opening, with the conductive support plate located within the opening.

11. The MPCVD system according to claim 8, characterized in that, The fixing part has a first water-cooling channel, the cooling part has a second water-cooling channel, and the furnace body has a third water-cooling channel; It also includes a water cooling device, which is connected to the first water cooling channel, the second water cooling channel and the third water cooling channel, and is used to provide cooling water to the first water cooling channel, the second water cooling channel and the third water cooling channel.

12. The MPCVD system according to claim 8, characterized in that, The microwave transmission module includes a microwave tuner, a rectangular waveguide, a coaxial waveguide, and a microwave plug. The input terminal of the microwave tuner is connected to the microwave power supply, and the output terminal of the microwave tuner is connected to the first end of the rectangular waveguide. The coaxial waveguide extends through the base plate and the support ring. The extension direction of the coaxial waveguide is perpendicular to the extension direction of the rectangular waveguide. The first end of the coaxial waveguide is connected to the second end of the rectangular waveguide, and the second end of the coaxial waveguide is connected to the fixed part. The coaxial waveguide includes a first part and a second part. The first part is located outside the reaction cavity and is made of metal. The second part is located inside the reaction cavity and is made of quartz. The microwave plug is located on the side of the coaxial waveguide away from the deposition stage; The support ring is made of quartz.

13. The MPCVD system according to claim 12, characterized in that, The connecting rod passes through the microwave plug and the coaxial waveguide, and the centerline of the connecting rod coincides with the centerline of the coaxial waveguide. The inner wall of the coaxial waveguide, the inner wall of the fixed part, and the outer wall of the connecting rod cooperate to form a first temperature-regulating cavity. The movable part has a second temperature-regulating cavity and a gas channel, and the second temperature-regulating cavity is connected to the first temperature-regulating cavity through the gas channel.

14. The MPCVD system according to claim 13, characterized in that, In the movable part, the conductive part, the high thermal conductivity insulating ring, and the cooling part cooperate to form the second temperature regulating cavity, and the cooling part has the gas channel; The connection channel is connected to the second temperature control cavity; The bias lead is electrically connected to the middle region of the conductive part within the second temperature-regulating cavity; or... The bias lead passes through the cooling section and the edge region of the high thermal conductivity insulating ring and the conductive section.

15. The MPCVD system according to claim 1, characterized in that, The microwave power supply has a power of 100kW.

16. The MPCVD system according to any one of claims 4-15, characterized in that, It also includes a bell jar located within the reaction chamber, the edge of which is sealed to the base plate; The air inlet and the air outlet are located on the base plate; The deposition stage, bias ring, support ring, air inlet, and air outlet are located inside the bell jar.

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