A reaction cavity 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 upper chamber, lower chamber and antenna, the large diameter end of the antenna passes through upper chamber and extends into lower chamber, the large diameter end is provided with boss, the diameter and height of the boss are Φ1 and H1 respectively, the boss divides upper chamber into first chamber and second chamber, the height of the first chamber and second chamber is H2 and H3 respectively, the second chamber is provided with the second dielectric ring with outer diameter Φ3, the H1=H2=H3, the Φ3<Φ1, provide a kind of reaction cavity, microwave feed-in efficiency is higher, impedance matching is better between the chamber, 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 low microwave feed efficiency, poor impedance matching, insufficiently stable and concentrated electric field, and low plasma density, resulting in a small discharge area that is unsuitable for the deposition of large-area diamond films, thus limiting its application prospects. 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: A reaction chamber includes an upper chamber, a lower chamber, and an antenna. The large-diameter end of the antenna passes through the upper chamber and extends into the lower chamber. The large-diameter end is provided with a boss. The diameter and height of the boss are Φ1 and H1, respectively. The boss divides the upper chamber into a first chamber and a second chamber. The heights of the first chamber and the second chamber are H2 and H3, respectively. The second chamber is provided with a second dielectric ring with an outer diameter of Φ3. H1 = H2 = H3, and Φ3 < Φ1.

[0007] Furthermore, the lower chamber is provided with an annular groove with a diameter of Φ4 and a height of H4 at one end near the upper chamber, where H4 = H1 and Φ3 < Φ4 < Φ1.

[0008] Furthermore, a molybdenum platform with a diameter of Φ5 is provided at the bottom of the lower chamber. The height of the molybdenum platform from the top surface of the lower chamber is H5, and the height between the lower end face of the large-diameter end and the boss is H6. H5 ≥ H6, and H5 = λ / 2.

[0009] Furthermore, the diameter of the larger diameter end is Φ6, where Φ6∶Φ5∈[1.2,1.5].

[0010] Furthermore, the lower end face of the large-diameter end is provided with a chamfer, and the diameter of the chamfered end face is Φ7, wherein Φ7 ≥ Φ5.

[0011] Furthermore, a working chamber with a diameter of Φ8 and a height of H7 is provided at the end of the lower chamber away from the upper chamber, wherein H7∶H4∈[1.5,2.5] and Φ8≥Φ4.

[0012] Furthermore, the inner diameter of the lower chamber is Φ9, where Φ9∶Φ6∈[1.2,2].

[0013] Furthermore, the distance from the top surface of the lower chamber to the top surface of the upper chamber is H8, where H8 < H5.

[0014] Furthermore, the inner diameter of the upper chamber is Φ 10 The Φ 10 :Φ8∈[1.1,1.5].

[0015] An MPCVD apparatus includes the reaction chamber.

[0016] This utility model has the following advantages: The large-diameter end of the antenna passes through the upper cavity and extends into the lower cavity. A boss is provided at the end of the large-diameter end away from the lower cavity. The diameter and height of the boss are Φ1 and H1, respectively. The boss divides the upper cavity into a first cavity and a second cavity. The heights of the first cavity and the second cavity are H2 and H3, respectively. The second cavity is provided with a second dielectric ring with an outer diameter of Φ3. H1 = H2 = H3, and Φ3 < Φ1, which makes the impedance matching between the cavities better, improves the efficiency of microwave feeding into the cavity, makes the electric field more stable and concentrated, and increases the plasma density, thereby facilitating the increase of the discharge area and continuous and stable discharge. Attached Figure Description

[0017] 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.

[0018] Figure 1 This is a cross-sectional schematic diagram of the reaction chamber of this utility model; Figure 2 This is a cross-sectional schematic diagram of the upper chamber of the reaction chamber of this utility model; Figure 3 This is a cross-sectional schematic diagram of the lower chamber of the reaction chamber of this utility model; Figure 4This is a cross-sectional view of the antenna of the reaction cavity of this utility model; Figure 5 This is a cross-sectional schematic diagram of the first medium ring of the reaction chamber of this utility model; Figure 6 This is a cross-sectional schematic diagram of the second medium ring in the reaction chamber of this utility model; Figure 7 This is a simulation diagram of the plasma field strength of the reaction chamber of this utility model; Figure 8 This is a simulation diagram of the plasma density in the reaction chamber of this invention; In the figure: 1-upper chamber, 11-first chamber, 12-second chamber, 2-lower chamber, 21-annular groove, 22-working chamber, 3-antenna, 31-small diameter end, 32-large diameter end, 321-protrusion, 4-first dielectric ring, 5-second dielectric ring, 6-molybdenum platform. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] like Figures 1 to 6 As shown, a reaction cavity includes an upper chamber 1, a lower chamber 2, and an antenna 3. The upper chamber 1, lower chamber 2, and antenna 3 are coaxial. The antenna 3 includes a small-diameter end 31 and a large-diameter end 32, which are coaxial. To match impedance and improve the efficiency of microwave feeding into the cavity, the large-diameter end 32 passes through the upper chamber 1 and extends into the lower chamber 2. A boss 321 is provided at the end of the large-diameter end 32 away from the lower chamber 2. The diameter and height of the boss 321 are Φ1 and H1, respectively. The boss 321 divides the upper chamber 1 into a first chamber 11 and a second chamber 12. The diameter of the boss 321 is smaller than the inner diameter of the upper chamber 1. The boss 321 is coaxial with the antenna 3. The heights of chamber 11 and the second chamber 12 are H2 and H3, respectively. The first chamber 11 is provided with a first dielectric ring 4 with an outer diameter of Φ2, and the second chamber 12 is provided with a second dielectric ring 5 with an outer diameter of Φ3. In order to maintain the vacuum in the lower chamber 2, the second dielectric ring 5 is sealed to the lower chamber 2 and the boss 321. The first dielectric ring 4 and the second dielectric ring 5 are both coaxial with the antenna 3, where H1 = H2 = H3 and Φ3 < Φ2 < Φ1. The first dielectric ring 4 and the second dielectric ring 5 can also serve to support and fix the antenna 3. In order to facilitate microwave transmission, the first dielectric ring 4 and the second dielectric ring 5 are made of a low dielectric constant material (such as quartz and ceramic).

[0024] Furthermore, in order to match the impedance, the lower chamber 2 is provided with an annular groove 21 with a diameter of Φ4 and a height of H4 at one end near the upper chamber 1. The annular groove 21 is coaxial with the lower chamber 2, H4 = H1, and Φ3 < Φ4 < Φ1.

[0025] Furthermore, a molybdenum platform 6 with a diameter of Φ5 is provided at the bottom of the lower chamber 2. The molybdenum platform 6 is coaxial with the lower chamber 2. The height of the molybdenum platform 6 to the top surface of the lower chamber 2 is H5. The height between the lower end face of the large-diameter end 32 and the boss 321 is H6. In order to obtain a stable electric field, H5 ≥ H6, H5 = λ / 2, where λ is the wavelength of the electromagnetic wave.

[0026] Furthermore, the diameter of the large-diameter end (32) is Φ6, where Φ6∶Φ5∈[1.2,1.5].

[0027] Furthermore, the lower end face of the large-diameter end 32 is provided with a chamfer, and the diameter of the chamfered end face is Φ7. In order to increase the discharge area, Φ7 ≥ Φ5.

[0028] Furthermore, in order to achieve stable discharge, a working chamber 22 with a diameter of Φ8 and a height of H7 is provided at the end of the lower chamber 2 away from the upper chamber 1. The working chamber 22 is coaxial with the lower chamber 2, and H7∶H4∈[1.5,2.5], and Φ8≥Φ4.

[0029] Furthermore, the inner diameter of the lower chamber 2 is Φ9. In order to improve microwave transmission efficiency, Φ9∶Φ6∈[1.2,2].

[0030] Furthermore, the distance from the top surface of the lower chamber 2 to the top surface of the upper chamber 1 is H8, and in order to achieve stable discharge, H8 < H5.

[0031] Furthermore, the inner diameter of the upper chamber 1 is Φ 10 In order to improve microwave transmission efficiency and achieve stable discharge, the Φ 10 :Φ8∈[1.1,1.5].

[0032] An MPCVD apparatus includes the reaction chamber.

[0033] Microwaves pass sequentially through the first chamber 11 and the second chamber 12 into the working chamber 22. The lower chamber 2 between the second chamber 12 and the working chamber 22 is used for matching transmission between the upper and lower chambers. The lower chamber 2 and the working chamber 22 form a "convex" shaped structure, which confines the plasma to the central region of the molybdenum stage 6, thereby facilitating the deposition of diamond film.

[0034] Simulation results demonstrate that the reaction cavity of this invention exhibits high efficiency, high impedance matching, and stable and concentrated electric field in the microwave feed chamber (see [link]). Figure 7 ), high plasma density (see) Figure 8 It has a large discharge area, making it suitable for depositing large-area diamond films.

[0035] The above description is merely a preferred embodiment of this utility model and is not intended to limit the 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 chamber, comprising an upper chamber (1), a lower chamber (2), and an antenna (3), characterized in that: The large-diameter end (32) of the antenna (3) passes through the upper chamber (1) and extends into the lower chamber (2). The large-diameter end (32) is provided with a boss (321). The diameter and height of the boss (321) are Φ1 and H1, respectively. The boss (321) divides the upper chamber (1) into a first chamber (11) and a second chamber (12). The heights of the first chamber (11) and the second chamber (12) are H2 and H3, respectively. The second chamber (12) is provided with a second dielectric ring (5) with an outer diameter of Φ3. H1 = H2 = H3, and Φ3 < Φ1.

2. The reaction chamber according to claim 1, characterized in that: The lower chamber (2) is provided with an annular groove (21) with a diameter of Φ4 and a height of H4 at one end near the upper chamber (1), wherein H4 = H1 and Φ3 < Φ4 < Φ1.

3. The reaction chamber according to claim 2, characterized in that: The bottom of the lower chamber (2) is provided with a molybdenum platform (6) with a diameter of Φ5. The height of the molybdenum platform (6) to the top surface of the lower chamber (2) is H5. The height between the lower end face of the large diameter end (32) and the boss (321) is H6. H5 ≥ H6 and H5 = λ / 2.

4. The reaction chamber according to claim 3, characterized in that: The diameter of the large-diameter end (32) is Φ6, where Φ6∶Φ5∈[1.2,1.5].

5. The reaction chamber according to claim 4, characterized in that: The lower end face of the large-diameter end (32) is provided with a chamfer, and the diameter of the end face of the chamfer is Φ7, wherein Φ7≥Φ5.

6. The reaction chamber according to claim 5, characterized in that: The lower chamber (2) is provided with a working chamber (22) with a diameter of Φ8 and a height of H7 at the end away from the upper chamber (1), wherein H7∶H4∈[1.5,2.5] and Φ8≥Φ4.

7. The reaction chamber according to claim 6, characterized in that: The inner diameter of the lower chamber (2) is Φ9, where Φ9∶Φ6∈[1.2,2].

8. The reaction chamber according to claim 7, characterized in that: The distance from the top surface of the lower chamber (2) to the top surface of the upper chamber (1) is H8, where H8 < H5.

9. The reaction chamber according to claim 8, characterized in that: The inner diameter of the upper chamber (1) is Φ 10 The Φ 10 :Φ8∈[1.1,1.5].

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

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