A reaction chamber and MPCVD device

Abstract

The utility model relates to the field of microwave plasma technology, more particularly to a kind of reaction cavity and MPCVD device, the reaction cavity includes antenna, the antenna is provided with dielectric plate between reaction cavity, the dielectric plate is low dielectric constant material, the dielectric plate is uniformly spaced, provide a kind of reaction cavity of electric field distribution uniformity, the MPCVD device includes the reaction cavity.

Description

Technical Field

[0001] This utility model relates to the field of microwave plasma technology, and more specifically, to a reaction cavity and an MPCVD device. Background Technology

[0002] Microwave plasma chemical vapor deposition (MPCVD) is an advanced method for preparing high-quality diamond films. This method requires a microwave plasma chemical vapor deposition apparatus. In MPCVD, microwaves generated by a microwave generator are introduced into the reaction chamber through a waveguide transmission system, and a mixture of methane and hydrogen gas is introduced. Under the excitation of microwaves, glow discharge is generated in the reaction chamber, which ionizes the molecules of the reaction gas and generates plasma, which is deposited on the sample to obtain a diamond film.

[0003] The reaction chamber of existing MPCVD devices has uneven electric field distribution, poor electric field mode matching, low efficiency of microwave feeding chamber, small discharge area, and non-concentrated electric field, making it unsuitable for the deposition of large-area diamond films. Utility Model Content

[0004] The purpose of this invention is to provide a reaction chamber to solve at least one of the technical problems in the prior art.

[0005] Another objective of this invention is to provide an MPCVD apparatus that includes the aforementioned reaction chamber.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] A reaction chamber includes an antenna, and a dielectric plate is disposed between the antenna and the reaction chamber. The dielectric plate is made of a low dielectric constant material and is evenly spaced.

[0008] Furthermore, the effective inner diameter of the medium plate is Φ1, and the inner diameter and height of the reaction chamber are Φ2 and H1, respectively, where Φ2∶Φ1∈[1.2,1.5] and H1∶Φ2∈[0.4,0.7].

[0009] Furthermore, the height of the medium plate from the bottom surface of the reaction chamber is H2, where H2∶H1∈[0.5,0.75].

[0010] Furthermore, the end face of the antenna is provided with a first ring and a protrusion, and the bottom surface of the reaction chamber is provided with a second ring and a molybdenum platform, with the first ring located above the second ring and the protrusion located above the molybdenum platform.

[0011] Furthermore, the diameter of the molybdenum platform is Φ3, and the diameter of the protrusion is Φ4, wherein Φ4 ≥ Φ3.

[0012] Furthermore, the inner and outer diameters of the first ring are Φ5 and Φ6, respectively, and the inner and outer diameters of the second ring are Φ7 and Φ8, respectively, wherein Φ5 > Φ7 and Φ6 < Φ8.

[0013] Furthermore, the height of the first ring is H3, and the height of the protrusion is H4, where H4 > H3.

[0014] Furthermore, the height of the second ring is H5, and the height of the molybdenum platform is H6, where H5 > H6.

[0015] An MPCVD apparatus includes the reaction chamber.

[0016] This utility model has the following advantages:

[0017] The antenna is coaxial with the reaction cavity. The end of the antenna is provided with a first annular groove, and the inner wall of the reaction cavity is provided with a second annular groove corresponding to the position of the first annular groove. The dielectric plate is an arc-shaped thin plate structure. The outer side of the dielectric plate is embedded in the first annular groove, and the inner side of the dielectric plate is embedded in the second annular groove. The dielectric plates are the same size and are evenly spaced around the center of the reaction cavity. The microwave is transmitted to the upper cavity through the antenna, and after being evenly split by the dielectric plate, it is transmitted to the lower cavity, so that the electric field distribution in the lower cavity is uniform. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional schematic diagram of the reaction chamber of this utility model;

[0020] Figure 2 for Figure 1 AA section diagram in the image;

[0021] Figure 3 for Figure 1 A magnified view of a portion of the image;

[0022] Figure 4 This is a simulation diagram of the plasma field strength of the reaction chamber of this utility model;

[0023] In the diagram: 1-antenna, 2-dielectric substrate, 3-first ring, 4-protrusion, 5-second ring, 6-molybdenum platform. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0026] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0027] In this invention, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] like Figures 1 to 3As shown, a reaction chamber includes an antenna 1 extending into the reaction chamber. To ensure uniform electric field distribution, four or six dielectric plates 2 are disposed between the end of the antenna 1 and the inner wall of the reaction chamber, dividing the reaction chamber into an upper chamber and a lower chamber. The upper and lower chambers are coaxial. The dielectric plates 2 are made of a low dielectric constant material (e.g., quartz and ceramic), and the four or six dielectric plates 2 are evenly spaced. Specifically, the antenna 1 is coaxial with the reaction chamber, and the end of the antenna 1 is provided with a first annular groove. The inner wall of the reaction chamber is provided with a groove that is aligned with the first annular groove. The dielectric plate 2 is an arc-shaped thin plate structure with a corresponding second annular groove. The outer side of the dielectric plate 2 is embedded in the first annular groove, and the inner side of the dielectric plate 2 is embedded in the second annular groove. The thickness of the dielectric plate 2 matches the first and second annular grooves. The number of dielectric plates 2 is 4 or 6 (4 in this embodiment). The dielectric plates 2 are the same size and are evenly spaced around the center of the reaction cavity. The microwave is transmitted to the upper cavity through the antenna 1, and after being evenly divided into 4 paths by the dielectric plates 2, it is transmitted to the lower cavity, so that the electric field distribution in the lower cavity is uniform.

[0029] Furthermore, the effective inner diameter of the dielectric plate 2 is Φ1, and the inner diameter and height of the reaction cavity are Φ2 and H1, respectively. In order to match the electric field mode, Φ2∶Φ1∈[1.2,1.5], and H1∶Φ2∈[0.4,0.7]. It should be noted that the effective inner diameter Φ1 of the dielectric plate 2 refers to the inner diameter of the path through which microwaves travel from the upper cavity to the lower cavity. In this embodiment, since the outer side of the dielectric plate 2 is embedded in the first annular groove at the end of the antenna 1, the effective inner diameter Φ1 of the dielectric plate 2 is equal to the maximum outer diameter at the end of the antenna 1.

[0030] Furthermore, the height of the dielectric plate 2 from the bottom surface of the reaction cavity is H2. In order to increase the efficiency of microwave feeding into the lower cavity, H2∶H1∈[0.5,0.75].

[0031] Furthermore, the end face of the antenna 1 is provided with a first ring 3 facing the bottom surface of the reaction cavity and a protrusion 4 facing the bottom surface of the reaction cavity. The bottom surface of the reaction cavity is provided with a second ring 5 facing the top surface of the reaction cavity and a molybdenum platform 6 facing the top surface of the reaction cavity. The first ring 3 is located directly above the second ring 5, and the protrusion 4 is located directly above the molybdenum platform 6. The first ring 3, the protrusion 4, the second ring 5, and the molybdenum platform 6 are all coaxial with the reaction cavity. The first ring 3 and the protrusion 4 can expand the discharge area, and the second ring 5 and the molybdenum platform 6 can concentrate the electric field.

[0032] Furthermore, the diameter of the molybdenum platform 6 is Φ3, and the diameter of the protrusion 4 is Φ4. In order to obtain a larger plasma sphere, Φ4 ≥ Φ3.

[0033] Furthermore, the inner and outer diameters of the first ring 3 are Φ5 and Φ6, respectively, and the inner and outer diameters of the second ring 5 are Φ7 and Φ8, respectively. In order to obtain a larger plasma sphere, Φ5 > Φ7 and Φ6 < Φ8.

[0034] Furthermore, the height of the first ring 3 is H3, and the height of the protrusion 4 is H4. In order to achieve stable discharge, H4 > H3.

[0035] Furthermore, the height of the second ring 5 is H5, and the height of the molybdenum platform 6 is H6. In order to concentrate the electric field, H5 > H6.

[0036] An MPCVD apparatus includes the reaction chamber.

[0037] Simulation results demonstrate that the reaction chamber of this invention features a concentrated electric field and a relatively large plasma sphere (see [link]). Figure 4 It is suitable for depositing large-area diamond films.

[0038] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A reaction cavity, comprising an antenna (1), characterized in that: A dielectric plate (2) is provided between the antenna (1) and the reaction cavity. The dielectric plate (2) is made of a low dielectric constant material. The antenna (1) and the reaction cavity are coaxial. The dielectric plates (2) are the same size and are evenly spaced around the center of the reaction cavity.

2. The reaction chamber according to claim 1, characterized in that: The effective inner diameter of the medium plate (2) is Φ1, and the inner diameter and height of the reaction chamber are Φ2 and H1, respectively, where Φ2∶Φ1∈[1.2,1.5] and H1∶Φ2∈[0.4,0.7].

3. The reaction chamber according to any one of claims 1 or 2, characterized in that: The height of the medium plate (2) from the bottom surface of the reaction chamber is H2, where H2:H1 ∈ [0.5, 0.75].

4. The reaction chamber according to claim 3, characterized in that: The antenna (1) has a first ring (3) and a protrusion (4) on its end face, and the reaction chamber has a second ring (5) and a molybdenum stage (6) on its bottom surface. The first ring (3) is located above the second ring (5), and the protrusion (4) is located above the molybdenum stage (6).

5. The reaction chamber according to claim 4, characterized in that: The diameter of the molybdenum platform (6) is Φ3, and the diameter of the protrusion (4) is Φ4, wherein Φ4 ≥ Φ3.

6. The reaction chamber according to claim 5, characterized in that: The inner and outer diameters of the first ring (3) are Φ5 and Φ6, respectively, and the inner and outer diameters of the second ring (5) are Φ7 and Φ8, respectively, wherein Φ5 > Φ7 and Φ6 < Φ8.

7. The reaction chamber according to claim 6, characterized in that: The height of the first ring (3) is H3, and the height of the protrusion (4) is H4, where H4 > H3.

8. The reaction chamber according to claim 7, characterized in that: The height of the second ring (5) is H5, and the height of the molybdenum platform (6) is H6, where H5 > H6.

9. An MPCVD apparatus, characterized in that: Includes the reaction chamber as described in any one of claims 1 to 8.

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