A variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage

Abstract

The present invention relates to the field of diamond film growth, and particularly to a variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage. The substrate of the sample stage is placed in the top groove of the molybdenum stage. A molybdenum bolt is vertically installed at the center of the bottom of the molybdenum stage. The sample stage support and the sample stage ceramic plate, which are horizontally arranged up and down, are combined with the left L-shaped vertical plate and the right L-shaped vertical plate, which are arranged relatively left and right, to form a cuboid frame structure. The molybdenum stage is fixed on the horizontally arranged sample stage ceramic plate through the molybdenum bolt. The sample stage support is fixed on the chamber bottom plate through the vertically arranged support bolt. The DC power supply is connected to the molybdenum stage through the power cord, the aviation seal joint, the high-temperature wire, and the molybdenum bolt in sequence. The present invention solves the problem of the uniformity of the negative bias electric field on the surface of the substrate in the reaction chamber during the deposition of diamond thin films by the microwave method, and prepares a high-quality diamond single crystal film with good uniformity, high purity, and good crystal morphology.

Description

Technical Field

[0001] The present invention relates to the field of diamond film growth, and particularly to a bias sample stage of a high-power microwave plasma chemical vapor deposition device with variable size. Background Art

[0002] The microwave plasma chemical vapor deposition (MPCVD) system, abbreviated as MPCVD, is a low-pressure deposition technology. The MPCVD device based on this technology is a key equipment for preparing diamond thin film materials. A series of key thin film materials can be synthesized by using MPCVD, such as diamond, graphene, silicon carbide, boron nitride and other materials. Among them, diamond thin film not only has excellent mechanical properties, but also its thermal and optical properties, including thermal conductivity, spectral transmission range, thermal shock resistance, etc., are also very excellent. Due to these excellent properties, diamond is an excellent optical window material and can be used for infrared thermal imaging missile domes. The optical window made of diamond thin film material can have a thermal shock resistance figure of merit as high as 106000 W(MPa)1 / 2 / cm, while in contrast, the thermal shock resistance figure of merit of ZnS commonly used for infrared optical windows is only 550 W(MPa) 1 / 2 / cm. Therefore, diamond thin film is particularly suitable for manufacturing various optical windows working in extremely harsh environments.

[0003] The MPCVD device is the preferred technology for preparing diamond thin film optical materials, but the main disadvantage of MPCVD is the low deposition rate of its diamond thin film. Especially when preparing diamond film materials with a large area, its deposition rate is generally only about 0.5 μm / h. The large-size diamond film windows such as 2 inches, 4 inches, 6 inches and 8 inches urgently needed in the industrial field have relatively high thickness requirements, generally requiring more than 0.5 mm. Therefore, ordinary high-power MPCVD cannot meet the requirements for growing large-size diamond window materials. Research shows that adding a negative bias voltage to the surface of the deposition substrate in the MPCVD device will help to improve the nucleation rate and deposition rate of diamond film on the substrate, and can meet the requirement of rapid growth of diamond film window materials. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a bias sample stage of a high-power microwave plasma chemical vapor deposition device with variable size, add a negative bias voltage to the surface of the deposition substrate in the MPCVD device, and ensure that substrates of different sizes use corresponding size molybdenum stages, and substrates of different sizes are in the same bias electric field gas atmosphere, so as to meet the requirement of rapid growth of diamond film window materials and ensure the consistency of film properties during batch coating.

[0005] The technical solution adopted by the present invention to solve its problems is as follows:

[0006] A variable-size bias sample stage for a high-power microwave plasma chemical vapor deposition device, the sample stage comprising: a support bolt, a sample stage support, a sample stage ceramic plate, a molybdenum bolt, a molybdenum stage, a substrate, a left L-shaped vertical plate, and a right L-shaped vertical plate. The specific structure is as follows:

[0007] The substrate is placed in the top groove of the molybdenum stage. A molybdenum bolt is installed vertically at the center of the bottom of the molybdenum stage. The sample stage support and the sample stage ceramic plate, which are horizontally arranged up and down, and the left L-shaped vertical plate and the right L-shaped vertical plate, which are arranged opposite to each other left and right, are combined into a cuboid frame structure. The molybdenum stage is fixed on the horizontally arranged sample stage ceramic plate through the molybdenum bolt, and the sample stage support is fixed on the chamber bottom plate through the vertically arranged support bolt.

[0008] For the variable-size bias sample stage of the high-power microwave plasma chemical vapor deposition device, the cuboid frame structure, the sample stage ceramic plate, the molybdenum bolt, the molybdenum stage, and the substrate are arranged in the reaction chamber. The reaction chamber is composed of a chamber upper cover, a sealing insulating pad, a chamber housing, and a chamber bottom plate, which are arranged from top to bottom in sequence. The chamber housing is arranged on the chamber bottom plate, the chamber upper cover is installed at the top of the chamber housing, and the chamber housing and the chamber upper cover are hermetically connected through the sealing insulating pad.

[0009] For the variable-size bias sample stage of the high-power microwave plasma chemical vapor deposition device, the chamber upper cover of the reaction chamber is physically grounded as the zero potential. The positive pole of the DC bias power supply is connected to the molybdenum stage through a power line, an aviation sealing joint, a high-temperature wire, and a molybdenum bolt in sequence. The negative pole of the DC bias power supply is physically grounded as the zero potential and forms a loop with the chamber upper cover of the reaction chamber. The DC bias power supply is an adjustable negative bias power supply of -500 to 0V.

[0010] The biased sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment described above. The molybdenum bolt is a combined structure of a molybdenum bolt rod, a molybdenum bolt upper end head, and a molybdenum bolt upper flat plate coaxially integrated. The top of the molybdenum bolt rod is the molybdenum bolt upper flat plate, and the top of the molybdenum bolt upper flat plate is the molybdenum bolt upper end head. A threaded hole is provided at the center of the bottom of the molybdenum stage. The molybdenum bolt is threadedly connected to the threaded hole at the center of the bottom of the molybdenum stage through the molybdenum bolt upper end head. The molybdenum bolt upper flat plate is located in the groove at the center of the top of the sample stage ceramic plate. A through hole is provided at the center of the sample stage ceramic plate, and the molybdenum bolt rod passes through the sample stage ceramic plate. A flake nut, a wire clamping bolt on the upper side, one end of a high-temperature wire, and a wire clamping bolt on the lower side are sequentially installed on the molybdenum bolt. The flake nut is threadedly connected to the molybdenum bolt and fixed to the bottom of the sample stage ceramic plate. The wire clamping bolt on the upper side is threadedly connected to the molybdenum bolt and fixed to the bottom of the flake nut. The wire clamping bolt on the lower side is threadedly connected to the molybdenum bolt. One end of the high-temperature wire is sleeved on the molybdenum bolt and clamped and fixed by the wire clamping bolt on the upper side and the wire clamping bolt on the lower side. The other end of the high-temperature wire is connected to an aviation sealing joint.

[0011] The biased sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment described above. The sample stage support is butted through a rabbet with the end of the horizontal short side of the left L-shaped vertical plate and the end of the horizontal short side of the right L-shaped vertical plate. The lower ends of the vertical long sides of the left L-shaped vertical plate and the right L-shaped vertical plate are butted with the sample stage support through a rabbet.

[0012] The biased sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment described above. The molybdenum stage and the molybdenum bolt are made of high-purity molybdenum material with a purity of more than 99.99 wt%. The sample stage ceramic plate is made of high-purity alumina material with a purity of more than 99.99 wt%. The sealing insulation pad is made of fluororubber. The chamber upper cover, the chamber housing, and the chamber bottom plate are made of aluminum alloy.

[0013] The biased sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment described above. The rated voltage of the high-temperature wire is 600V, the working temperature is -65 to 200 °C, and its insulating layer is Teflon.

[0014] The design concept of the present invention is: The present invention designs a biased sample stage for a variable-size high-power microwave plasma chemical vapor deposition equipment. A negative bias voltage is applied to the surface of the deposition substrate in the MPCVD device. Molybdenum stages with corresponding sizes are designed for substrates of different sizes under the action of the negative bias electric field. According to the diamond nucleation mechanism and the action mechanism of the bias electric field, samples of different sizes are all in the same bias electric field gas atmosphere, so as to realize the rapid growth of diamond thin film materials with consistent film properties on samples of different sizes.

[0015] The present invention is applicable to the biased sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment, and has the following advantages and beneficial effects:

[0016] 1. Based on the original high-power MPCVD, the present invention uses a ceramic plate of the sample stage to replace the original molybdenum substrate stage. A molybdenum stage is placed on the ceramic plate of the sample stage, and the molybdenum stage is connected to the negative bias power supply line to form a negative bias electric field on the surface of the substrate, improving the nucleation rate of carbon ions on the surface of the substrate and meeting the requirement for rapid growth of the diamond film window material.

[0017] 2. In the present invention, molybdenum stages of corresponding different sizes are used for substrates of different sizes, so that different positions on the surfaces of substrates of different sizes are in the same field strength atmosphere, thereby ensuring the consistency of the film performance during large-area coating.

[0018] 3. The structure of the present invention is simple, easy to manufacture, the molybdenum stage can be disassembled and replaced conveniently and quickly, and the cost is low, having an efficient and ideal application effect in laboratories and industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a structural diagram of the present invention.

[0020] In the figure: 1 - upper cover of the chamber; 2 - sealing insulating gasket; 3 - chamber housing; 4 - chamber bottom plate; 5 - DC bias power supply; 6 - power supply line; 7 - aviation sealing joint; 8 - high-temperature wire; 9 - support bolt; 10 - sample stage support; 11 - ceramic plate of the sample stage; 12 - molybdenum bolt; 13 - molybdenum stage; 14 - substrate; 15 - left L-shaped vertical plate; 16 - right L-shaped vertical plate.

[0021] Figure 2 is Figure 1 a partial enlarged view of A in. In the figure: 11 - ceramic plate of the sample stage; 12 - molybdenum bolt; 13 - molybdenum stage; 14 - substrate; 17 - clamping bolt on the wire; 18 - clamping bolt under the wire; 19 - molybdenum bolt rod; 20 - upper end of the molybdenum bolt; 21 - upper flat plate of the molybdenum bolt; 22 - sheet nut.

[0022] Figs. 3(a) - 3(d) are the external dimension diagrams of the main models of four sizes of molybdenum stages of the bias sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment of the present invention. Among them, Fig. 3(a) is the first molybdenum stage, Fig. 3(b) is the second molybdenum stage, Fig. 3(c) is the third molybdenum stage, and Fig. 3(d) is the fourth molybdenum stage. In the figure: 13 - molybdenum stage; 23 - groove; 24 - threaded hole. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, in conjunction with the accompanying drawings and embodiments, the specific embodiments of the invention will be further described in detail. For the detailed description of these embodiments, it should be understood that those skilled in the art can practice the present invention, and can make changes and / or modifications to the illustrated examples without departing from the spirit of the appended claims and the scope of the present invention. In addition, although specific features of the present invention are disclosed in the embodiments, such specific features can be appropriately changed to achieve the functions of the present invention.

[0024] As Figure 1 - shown in Figure 3, the bias sample stage of the high-power microwave plasma chemical vapor deposition equipment of the present invention mainly includes: a chamber upper cover 1, a sealing insulating gasket 2, a chamber housing 3, a chamber bottom plate 4, a DC bias power supply 5, a power cord 6, an aviation sealing joint 7, a high-temperature wire 8, a support bolt 9, a sample stage support 10, a sample stage ceramic plate 11, a molybdenum bolt 12, a molybdenum stage 13, a substrate 14, a left L-shaped vertical plate 15, a right L-shaped vertical plate 16, etc. The specific structure is as follows:

[0025] The substrate 14 is placed in the top groove 23 of the molybdenum stage 13. A molybdenum bolt 12 is installed vertically at the center of the bottom of the molybdenum stage 13. The sample stage support 10 and the sample stage ceramic plate 11, which are horizontally arranged up and down, and the left L-shaped vertical plate 15 and the right L-shaped vertical plate 16, which are arranged left and right, are combined into a cuboid frame structure. The molybdenum stage 13 is fixed on the horizontally arranged sample stage ceramic plate 11 through the molybdenum bolt 12, and the sample stage support 10 is fixed on the chamber bottom plate 4 through the vertically arranged support bolt 9;

[0026] The chamber upper cover 1, the sealing insulating gasket 2, the chamber housing 3, and the chamber bottom plate 4, which are arranged from top to bottom in sequence, form a reaction chamber. The chamber housing 3 is arranged on the chamber bottom plate 4. The chamber upper cover 1 is installed on the top of the chamber housing 3. The chamber housing 3 and the chamber upper cover 1 are hermetically connected through the sealing insulating gasket 2. The cuboid frame structure and the sample stage ceramic plate 11, the molybdenum bolt 12, the molybdenum stage 13, and the substrate 14 are arranged in the reaction chamber.

[0027] The molybdenum bolt 12 is a combined structure of a molybdenum bolt rod 19, a molybdenum bolt upper end head 20, and a molybdenum bolt upper flat plate 21 coaxially integrated. The top of the molybdenum bolt rod 19 is the molybdenum bolt upper flat plate 21, and the top of the molybdenum bolt upper flat plate 21 is the molybdenum bolt upper end head 20. A threaded hole 24 is provided at the center of the bottom of the molybdenum table 13. The molybdenum bolt 12 is threadedly connected to the threaded hole 24 at the center of the bottom of the molybdenum table 13 through the molybdenum bolt upper end head 20. The molybdenum bolt upper flat plate 21 is located in the groove at the center of the top of the sample stage ceramic plate 11. A through hole is provided at the center of the sample stage ceramic plate 11, and the molybdenum bolt rod 19 passes through the sample stage ceramic plate 11. A flake nut 22, a wire clamping bolt 17, one end of a high-temperature wire 8, and a wire clamping bolt 18 are sequentially installed on the molybdenum bolt 12. The flake nut 22 is threadedly connected to the molybdenum bolt 12 and fixed to the bottom of the sample stage ceramic plate 11. The wire clamping bolt 17 is threadedly connected to the molybdenum bolt 12 and fixed to the bottom of the flake nut 22. The wire clamping bolt 18 is threadedly connected to the molybdenum bolt 12. One end of the high-temperature wire 8 is sleeved on the molybdenum bolt 12 and clamped and fixed by the wire clamping bolt 17 and the wire clamping bolt 18. The other end of the high-temperature wire 8 is connected to the aviation seal joint 7.

[0028] The sample stage support 10 is butted through a rabbet with the end of the horizontal short side of the left L-shaped vertical plate 15 and the end of the horizontal short side of the right L-shaped vertical plate 16. The lower end of the vertical long side of the left L-shaped vertical plate 15 and the lower end of the vertical long side of the right L-shaped vertical plate 16 are butted with the sample stage support 10 through a rabbet.

[0029] As shown in FIGS. 3(a)-3(d), the main external dimension diagrams of the four sizes of molybdenum tables of the biasing sample stage of the variable-size high-power microwave plasma chemical vapor deposition equipment of the present invention. The center of the top of the molybdenum table 13 is a groove 23, and the center of the bottom of the molybdenum table 13 is a threaded hole 24. Among them, FIG. 3(a) shows the effective size of the first molybdenum table groove 23, Φ = 2 inches (52 ± 0.1 mm), FIG. 3(b) shows the effective size of the second molybdenum table groove 23, Φ = 4 inches (104 ± 0.1 mm), FIG. 3(c) shows the effective size of the third molybdenum table groove, Φ = 6 inches (156 ± 0.1 mm), and FIG. 3(d) shows the effective size of the fourth molybdenum table groove, Φ = 8 inches (208 ± 0.1 mm).

[0030] The molybdenum table 13 and the molybdenum bolt 12 are made of high-purity molybdenum material with a purity of 99.99 wt% or more. The sample stage ceramic plate 11 is made of high-purity alumina material with a purity of 99.99 wt% or more. The sealing insulating pad 2 is made of fluororubber. The chamber upper cover 1, the chamber housing 3, and the chamber bottom plate 4 are made of aluminum alloy.

[0031] The rated voltage of the high-temperature wire 8 is 600V, the working temperature is -65 to 200°C, and its insulating layer is Teflon.

[0032] The upper chamber cover 1 of the reaction chamber is physically grounded as the zero potential. The positive pole of the DC bias power supply 5 is sequentially connected to the molybdenum stage 13 through the power line 6, the aviation sealing joint 7, the high-temperature wire 8, and the molybdenum bolt 12. The negative pole of the DC bias power supply 5 is physically grounded as the zero potential through the power line to form a loop with the upper chamber cover 1 of the reaction chamber. The DC bias power supply 5 is an adjustable negative bias power supply of -500 to 0V.

[0033] The results show that the present invention solves the problem of the uniformity of the negative bias electric field on the surface of the substrate in the reaction chamber during the deposition of diamond films by the microwave chemical vapor deposition method. It can ensure that substrates of different sizes use corresponding-sized molybdenum stages, and the molybdenum stages can be disassembled and replaced conveniently and quickly, so that different positions on the surfaces of substrates of different sizes are in the same field strength atmosphere, thereby ensuring the consistency of the film performance during large-area coating. Diamond films can be deposited on substrates of different sizes to prepare high-quality diamond single crystal films with different areas, good uniformity, high purity, and good crystal morphology.

[0034] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit and scope protected by the present invention and the claims. These all fall within the protection scope of the present invention.

Claims

1. A variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage, characterized in that, The sample stage includes: support bolts, sample stage supports, sample stage ceramic plates, molybdenum bolts, molybdenum stages, substrates, left L-shaped vertical plates, and right L-shaped vertical plates. The specific structure is as follows: Molybdenum stages with corresponding sizes are designed for substrates of different sizes. The substrate is placed in the top groove of the molybdenum stage. A molybdenum bolt is installed vertically at the center of the bottom of the molybdenum stage. The sample stage supports and sample stage ceramic plates, which are horizontally arranged opposite to each other up and down, and the left L-shaped vertical plate and right L-shaped vertical plate, which are arranged opposite to each other left and right, are combined into a cuboid frame structure. The molybdenum stage is fixed on the horizontally arranged sample stage ceramic plate through the molybdenum bolt, and the sample stage support is fixed on the chamber bottom plate through the vertically arranged support bolt; The cuboid frame structure, sample stage ceramic plate, molybdenum bolt, molybdenum stage, and substrate are arranged in the reaction chamber. The reaction chamber is composed of a chamber upper cover, a sealing insulation pad, a chamber housing, and a chamber bottom plate, which are arranged from top to bottom in sequence. The chamber housing is arranged on the chamber bottom plate, the chamber upper cover is installed at the top of the chamber housing, and the chamber housing and the chamber upper cover are hermetically connected through the sealing insulation pad; The chamber upper cover of the reaction chamber is physically grounded as the zero potential. The positive pole of the DC bias power supply is connected to the molybdenum stage through a power line, an aviation sealing joint, a high-temperature wire, and a molybdenum bolt in sequence. The negative pole of the DC bias power supply is physically grounded as the zero potential and forms a loop with the chamber upper cover of the reaction chamber. The DC bias power supply is an adjustable negative bias power supply of -500 to 0V; The molybdenum bolt is a combined structure of a molybdenum bolt rod, a molybdenum bolt upper end head, and a molybdenum bolt upper flat plate coaxially integrated. The top of the molybdenum bolt rod is the molybdenum bolt upper flat plate, and the top of the molybdenum bolt upper flat plate is the molybdenum bolt upper end head. A threaded hole is provided at the center of the bottom of the molybdenum stage. The molybdenum bolt is threadedly connected to the threaded hole at the center of the bottom of the molybdenum stage through the molybdenum bolt upper end head. The molybdenum bolt upper flat plate is located in the groove at the center of the top of the sample stage ceramic plate. A through hole is provided at the center of the sample stage ceramic plate, and the molybdenum bolt rod passes through the sample stage ceramic plate. A sheet nut, a wire upper clamping bolt, one end of a high-temperature wire, and a wire lower clamping bolt are installed on the molybdenum bolt in sequence. The sheet nut is threadedly connected to the molybdenum bolt and fixed at the bottom of the sample stage ceramic plate. The wire upper clamping bolt is threadedly connected to the molybdenum bolt and fixed at the bottom of the sheet nut. The wire lower clamping bolt is threadedly connected to the molybdenum bolt. One end of the high-temperature wire is sleeved on the molybdenum bolt and clamped and fixed by the wire upper clamping bolt and the wire lower clamping bolt. The other end of the high-temperature wire is connected to the aviation sealing joint.

2. The variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage according to claim 1, characterized in that, The sample stage support is butted through a rabbet with the end of the horizontal short side of the left L-shaped vertical plate and the end of the horizontal short side of the right L-shaped vertical plate. The lower ends of the vertical long sides of the left L-shaped vertical plate and the right L-shaped vertical plate are butted with the sample stage support through a rabbet.

3. The variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage according to claim 1, characterized in that, The molybdenum stage and molybdenum bolt are made of high-purity molybdenum material with a purity of more than 99.99wt%. The sample stage ceramic plate is made of high-purity alumina material with a purity of more than 99.99wt%. The sealing insulation pad is made of fluororubber. The chamber upper cover, chamber housing, and chamber bottom plate are made of aluminum alloy.

4. The variable-size high-power microwave plasma chemical vapor deposition equipment bias sample stage according to claim 1, characterized in that, The rated voltage of the high-temperature wire is 600V, the working temperature is -65 to 200°C, and its insulating layer is Teflon.

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