Substrate table for preparing monocrystal diamond by microwave plasma

Abstract

The utility model discloses a substrate table for preparing monocrystal diamond by microwave plasma, which relates to the technical field of monocrystal diamond preparation and comprises a first molybdenum plate and a first molybdenum ring, the first molybdenum plate is used for bearing seed crystal, and a first groove is arranged on the bottom surface of the first molybdenum ring. The inner side wall of the first groove can be tightly attached to the outer side wall of the first molybdenum sheet, and a first through hole is formed in the inner top surface of the first groove; according to the substrate table for preparing the monocrystal diamond through the microwave plasma, the utilization rate of plasma energy can be increased.

Description

Technical Field

[0001] The utility model relates to the technical field of single crystal diamond preparation, in particular to a substrate table used for preparing single crystal diamond by microwave plasma. Background Art

[0002] Diamond has attracted wide attention and applications in various fields due to its excellent physical and chemical properties. Chemical vapor deposition technology is one of the main methods for preparing high-quality single-crystal diamond films. Among them, microwave plasma chemical vapor deposition (MPCVD) is regarded as the preferred method for preparing high-quality diamond films due to its advantages such as non-polar discharge, high energy conversion efficiency and pure plasma. In order to grow single-crystal diamond, a substrate stage is required as a single-crystal diamond growth carrier.

[0003] There is a substrate table, which is a circular molybdenum sheet. A groove is designed on the surface of the substrate table. The groove is square in shape and 2 mm deep. When in use, a single crystal diamond seed crystal with a certain thickness grown initially is placed in the growth area of ​​the substrate table for secondary growth.

[0004] However, during the growth of single crystal diamond, high-power plasma will produce discharges on the edges of the circular molybdenum sheet and the edges of the square grooves, resulting in reduced utilization of plasma energy. This will not only affect the growth environment of the single crystal diamond, causing polycrystalline to easily form on the edges of the substrate table and the edges of the square grooves, but will also have a negative impact on subsequent processing after the growth is completed, reducing the quality of the finished product while indirectly increasing the cost of multiple growth of single crystal diamonds. There is a problem of slowing growth after deposition to a certain thickness in the initial growth environment, making it difficult to control the growth of single crystal diamonds with a higher thickness. Utility Model Content

[0005] The purpose of the utility model is to provide a substrate table for preparing single crystal diamond by microwave plasma, so as to solve the problems existing in the above-mentioned prior art and improve the utilization rate of plasma energy.

[0006] To achieve the above purpose, the utility model provides the following solutions:

[0007] The utility model provides a substrate table for preparing single-crystal diamond by microwave plasma, comprising a first molybdenum sheet and a first molybdenum ring, wherein the first molybdenum sheet is used to carry a seed crystal, the first molybdenum ring is used to be placed above the first molybdenum sheet, a first groove is provided on the bottom surface of the first molybdenum ring, the inner side wall of the first groove can be tightly fitted with the outer side wall of the first molybdenum sheet, and a first through hole is provided on the inner top surface of the first groove.

[0008] Preferably, a second molybdenum sheet is further included, the cross section of the second molybdenum sheet is the same as the cross section of the first molybdenum sheet, and the second molybdenum sheet is used to be placed between the first molybdenum sheet and the first molybdenum ring, and placed above the first molybdenum sheet.

[0009] Preferably, it also includes a second molybdenum ring, which is used to be placed above the first molybdenum ring. A second groove is provided on the bottom surface of the second molybdenum ring. The inner wall of the second groove can fit tightly with the outer wall of the first molybdenum ring. A second through hole is provided on the inner top surface of the second groove.

[0010] Preferably, a third molybdenum ring is further included, and the third molybdenum ring is used to be placed above the second molybdenum ring. A third groove is provided on the bottom surface of the third molybdenum ring, and the inner wall of the third groove can fit tightly with the outer wall of the second molybdenum ring. A third through hole is provided on the inner top surface of the third groove.

[0011] Preferably, the cross-section of the first molybdenum sheet is circular, and the cross-sections of the first molybdenum ring, the second molybdenum ring and the third molybdenum ring are all annular.

[0012] Preferably, the diameters of the first through hole, the second through hole and the third through hole are equal.

[0013] Preferably, the diameter of the third through hole is 74 mm.

[0014] Preferably, the thickness of the first molybdenum sheet is 10.0 mm, the thickness of the second molybdenum sheet is 3.0 mm, and the thickness of the first molybdenum ring, the second molybdenum ring and the third molybdenum ring are all 2.0 mm.

[0015] Compared with the prior art, the utility model has achieved the following technical effects:

[0016] The utility model provides a substrate stage for preparing single crystal diamond by microwave plasma, wherein a first molybdenum sheet is used to carry a seed crystal, a first molybdenum ring is used to be placed above the first molybdenum sheet, a first groove is provided on the bottom surface of the first molybdenum ring, an inner side wall of the first groove can be tightly fitted with an outer side wall of the first molybdenum sheet, a first through hole is provided on the inner top surface of the first groove, and a seed crystal growth space is formed by the cooperation of the first molybdenum sheet and the first molybdenum ring, thereby avoiding discharge at the edge of the substrate stage in a plasma environment, reducing polycrystalline generation at the edge of the substrate stage, and improving the utilization rate of plasma energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 A three-dimensional schematic diagram of a substrate stage for preparing single crystal diamond by microwave plasma provided by the utility model;

[0019] Figure 2 A schematic diagram of a main view of a substrate stage for preparing single crystal diamond by microwave plasma provided by the utility model;

[0020] Figure 3 A schematic cross-sectional view of a substrate stage for preparing single crystal diamond using microwave plasma provided by the utility model;

[0021] In the figure: 1-first molybdenum sheet, 2-second molybdenum sheet, 3-first molybdenum ring, 4-second molybdenum ring, 5-third molybdenum ring. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] The purpose of the utility model is to provide a substrate table for preparing single crystal diamond by microwave plasma, so as to solve the problems existing in the above-mentioned prior art and improve the utilization rate of plasma energy.

[0024] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0025] like Figure 1-3 As shown, the utility model provides a substrate stage for preparing single crystal diamond by microwave plasma, comprising a first molybdenum sheet 1 and a first molybdenum ring 3, wherein the first molybdenum sheet 1 is used to carry a seed crystal, a first groove is provided on the bottom surface of the first molybdenum ring 3, the inner side wall of the first groove can be tightly fitted with the outer side wall of the first molybdenum sheet 1, and a first through hole is provided on the inner top surface of the first groove.

[0026] The utility model provides a substrate stage for preparing single crystal diamond by microwave plasma, wherein a first molybdenum sheet 1 is used to carry a seed crystal, a first molybdenum ring 3 is used to be placed above the first molybdenum sheet 1, a first groove is provided on the bottom surface of the first molybdenum ring 3, the inner side wall of the first groove can fit tightly with the outer side wall of the first molybdenum sheet 1, a first through hole is provided on the inner top surface of the first groove, and the first molybdenum sheet 1 and the first molybdenum ring 3 cooperate to form a seed crystal growth space, thereby avoiding discharge at the edge of the substrate stage in a plasma environment, reducing polycrystalline generation at the edge of the substrate stage, and improving the utilization rate of plasma energy; it should be noted that the surface of the first molybdenum sheet 1 for carrying the seed crystal needs to be smooth and flat, and the outer surface of the first molybdenum ring 3 needs to be designed without a tip to avoid the problem of edge discharge in plasma.

[0027] Furthermore, the substrate stage for preparing single-crystal diamond by microwave plasma provided by the utility model also includes a second molybdenum sheet 2. The cross-section of the second molybdenum sheet 2 is the same as the cross-section of the first molybdenum sheet 1. The second molybdenum sheet 2 is used to be placed between the first molybdenum sheet 1 and the first molybdenum ring 3, and is placed above the first molybdenum sheet 1, so that the seed crystal can be raised by the second molybdenum sheet 2 in the initial growth stage of the seed crystal. After the initial growth stage, the second molybdenum sheet 2 is removed so that the subsequent growth position is at a height similar to that in the initial growth stage, thereby reducing the relative height between the growth surface of the seed crystal and the plasma, obtaining a growth environment similar to that in the initial growth stage, and reducing the accumulation of lattice defects and increased stress caused by multiple growth of single-crystal diamond.

[0028] Furthermore, the substrate table for preparing single-crystal diamond by microwave plasma provided by the utility model also includes a second molybdenum ring 4, which is used to be placed above the first molybdenum ring 3. A second groove is provided on the bottom surface of the second molybdenum ring 4, and the inner wall of the second groove can fit tightly with the outer wall of the first molybdenum ring 3. A second through hole is provided on the inner top surface of the second groove. After removing the second molybdenum sheet 2, the second molybdenum ring 4 cooperates with the first molybdenum sheet 1 and the first molybdenum ring 3 to form a space for the seed crystal to continue to grow.

[0029] Furthermore, the substrate stage for preparing single crystal diamond by microwave plasma provided by the utility model also includes a third molybdenum ring 5, which is used to be placed above the second molybdenum ring 4, and a third groove is provided on the bottom surface of the third molybdenum ring 5, and the inner wall of the third groove can be tightly fitted with the outer wall of the second molybdenum ring 4, and a third through hole is provided on the inner top surface of the third groove. The third molybdenum ring 5 cooperates with the second molybdenum ring 4, the first molybdenum sheet 1 and the first molybdenum ring 3 to form a space for the seed crystal to continue to grow. In practical applications, the substrate stage can be adjusted and matched in various styles according to actual production needs to adapt to the single crystal diamond deposition requirements with different process parameters; as a more preferred implementation method of this embodiment, the tops of the third molybdenum ring 5 and the second molybdenum ring 4 are both smooth rounded structures, which can enable the edge of the single crystal diamond to receive the plasma ball energy more evenly, while enhancing the heat dissipation of this area, so that the diamond grows more evenly.

[0030] As a more preferred implementation of this embodiment, the cross-section of the first molybdenum sheet 1 is circular, and the cross-sections of the first molybdenum ring 3, the second molybdenum ring 4 and the third molybdenum ring 5 are all circular rings. The structure is simple and easy to use, and the problem of edge discharge in plasma is effectively avoided.

[0031] Furthermore, the diameters of the first through hole, the second through hole and the third through hole are equal, so that the cross sections of the grown single crystal diamond at different heights are consistent.

[0032] As a more preferred implementation of this embodiment, the diameter of the third through hole is 74 mm.

[0033] As a more preferred implementation of this embodiment, the thickness of the first molybdenum sheet 1 is 10.0 mm, the thickness of the second molybdenum sheet 2 is 3.0 mm, and the thickness of the first molybdenum ring 3, the second molybdenum ring 4 and the third molybdenum ring 5 are all 2.0 mm.

[0034] In order to control the growth of single-crystal diamond with a relatively high thickness, the problem of slowing down the growth after being deposited to a certain thickness in the initial growth environment is solved. A deposition process of multiple growths is adopted, and the substrate stage for preparing single-crystal diamond by microwave plasma provided by the utility model is used to achieve stable growth of single-crystal diamond. For example, in the initial stage of producing amethyst with a single-crystal diamond thickness of less than 1 mm, a first molybdenum sheet 1 with a thickness of 10 mm, a second molybdenum sheet 2 with a thickness of 3 mm and a first molybdenum ring 3 are used for growth. The design of mutually fitting contact surfaces of adjacent components avoids the problem of uneven plasma environment temperature caused by gap discharge, so that the single-crystal diamond at each position grows evenly, and the abnormal growth in a local area is prevented from affecting the growth. Affects the quality of finished products; after the seed crystal grows to a thickness of 2-3mm, the diamond growth rate drops significantly due to factors such as the seed crystal thickness and the plasma volume. At this time, the first molybdenum sheet 1, the first molybdenum ring 3 and the second molybdenum ring 4 with a thickness of 10mm are used to carry out the second stage of diamond growth, wherein the removal of the second molybdenum sheet 2 makes the second stage of diamond growth surface contacting the plasma environment consistent with the initial growth stage, solving the problem of slowing growth rate caused by different plasma electric field and magnetic field environments at different heights of the growth surface; according to production requirements, the first molybdenum sheet 1, the first molybdenum ring 3, the second molybdenum ring 4 and the third molybdenum ring 5 with a thickness of 10mm are used to carry out the third stage of diamond growth. The design of the multi-layer molybdenum sheet and multi-layer molybdenum ring for the substrate table for preparing single crystal diamond by microwave plasma provided by the utility model can reduce the difficulty of substrate processing, simplify the processing procedure, and reduce the production and use costs.

[0035] A specific method of using the substrate stage for preparing single crystal diamond by microwave plasma provided by the utility model:

[0036] S1: Assemble the substrate stage, place the second molybdenum sheet 2 on the first molybdenum sheet 1; stack the first molybdenum ring 3 on the second molybdenum sheet 2, and align the first molybdenum sheet 1, the second molybdenum sheet 2 and the first molybdenum ring 3 concentrically;

[0037] S2: Arrange a plurality of seed crystals of appropriate sizes on the first molybdenum sheet 1 in a reasonable manner;

[0038] S3: Single crystal diamond deposition, placing the substrate table with the seed crystal on the corresponding position of the MPCVD equipment, that is, on the cooling table in the deposition chamber, waiting for the growth of single crystal diamond. During this process, the electromagnetic waves generated by the microwave equipment excite the low-pressure reaction gas in the deposition chamber to produce a plasma ball to stimulate the growth of diamond;

[0039] S4: taking out the grown diamond and taking out the substrate table from the MPCVD equipment;

[0040] S5: measuring the deposition thickness of the seed crystal in the initial stage, assembling the substrate stage of the second stage, removing the second molybdenum sheet 2, stacking the first molybdenum ring 3 and the second molybdenum ring 4, and concentrically aligning the first molybdenum ring 3, the second molybdenum ring 4 and the first molybdenum sheet 1;

[0041] S6: repeat S3 to perform secondary deposition of single crystal diamond;

[0042] S7: Repeat S4.

[0043] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A substrate stage for preparing single crystal diamond by microwave plasma, characterized in that: It includes a first molybdenum sheet and a first molybdenum ring. The first molybdenum sheet is used to carry a seed crystal. The first molybdenum ring is used to be placed above the first molybdenum sheet. A first groove is provided on the bottom surface of the first molybdenum ring. The inner side wall of the first groove can fit tightly with the outer side wall of the first molybdenum sheet. A first through hole is provided on the inner top surface of the first groove.

2. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 1, characterized in that: It also includes a second molybdenum sheet, the cross section of the second molybdenum sheet is the same as the cross section of the first molybdenum sheet, and the second molybdenum sheet is used to be placed between the first molybdenum sheet and the first molybdenum ring, and placed above the first molybdenum sheet.

3. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 2, characterized in that: It also includes a second molybdenum ring, which is used to be placed above the first molybdenum ring. A second groove is opened on the bottom surface of the second molybdenum ring. The inner wall of the second groove can fit tightly with the outer wall of the first molybdenum ring. A second through hole is opened on the inner top surface of the second groove.

4. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 3, characterized in that: It also includes a third molybdenum ring, which is used to be placed above the second molybdenum ring. A third groove is opened on the bottom surface of the third molybdenum ring. The inner wall of the third groove can fit tightly with the outer wall of the second molybdenum ring. A third through hole is opened on the inner top surface of the third groove.

5. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 4, characterized in that: The cross section of the first molybdenum sheet is circular, and the cross sections of the first molybdenum ring, the second molybdenum ring and the third molybdenum ring are all annular.

6. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 5, characterized in that: The diameters of the first through hole, the second through hole and the third through hole are equal.

7. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 6, characterized in that: The diameter of the third through hole is 74 mm.

8. The substrate stage for preparing single crystal diamond by microwave plasma according to claim 5, characterized in that: The thickness of the first molybdenum sheet is 10.0 mm, the thickness of the second molybdenum sheet is 3.0 mm, and the thickness of the first molybdenum ring, the second molybdenum ring and the third molybdenum ring are all 2.0 mm.

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