MPCVD deposition chamber for improving gas distribution

Abstract

The utility model relates to an MPCVD deposition chamber for improving gas distribution, which comprises a deposition chamber body, the deposition chamber body is provided with a top cover part, a bowl-shaped baffle plate with an upward opening is arranged in the deposition chamber body and is positioned at the lower end of the top cover part, the bowl-shaped baffle plate and the top cover part form a first gas mixing cavity, and a plurality of gas outlet holes are uniformly distributed in the bowl-shaped baffle plate; a cone-frustum-shaped shell is arranged in the first gas mixing cavity, the shell is of a hollow structure, a second gas mixing cavity is formed in the shell, the gas inlet pipe is communicated with the second gas mixing cavity, the side wall and the bottom of the shell are each provided with a flow dividing part, and flow dividing holes communicated with the second gas mixing cavity are formed in the flow dividing parts. The gas entering the deposition chamber is uniformly mixed, so that the problems of non-uniform plasma electric field distribution and excessive carbon deposition in the middle area of the molybdenum table caused by non-uniform mixing of the gas entering the deposition chamber can be effectively avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of diamond production, in particular to an MPCVD deposition chamber with improved gas distribution. Background Art

[0002] Microwave plasma chemical vapor deposition, abbreviated as MPCVD, is a process technology that uses a waveguide to pass microwaves generated by a microwave generator into a deposition chamber through an isolator, excites gas molecules in the deposition chamber to ionize and generate plasma, which reacts on the surface of the substrate in the deposition chamber to generate a solid material film, and then deposits solid materials.

[0003] At present, the deposition chamber of the existing diamond MPCVD device is as follows Figure 3 As shown, it includes a deposition chamber body, and an air inlet pipe is provided at the center of the upper end of the deposition chamber body. An air inlet structure of intermediate direct injection is adopted. Although the process gas has been mixed before the air intake, due to the excessive length of the delivery pipeline and the different gas qualities, the originally mixed process gas is stratified again, that is, the mixing is insufficient. The insufficiently mixed process gas will lead to uneven distribution of the plasma electric field and excessive carbon deposition in the middle area of ​​the molybdenum table, thereby affecting the growth efficiency and growth quality of the diamond crystal. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides an MPCVD deposition chamber with improved gas distribution.

[0005] The utility model adopts a technical solution to solve the above technical problems: an MPCVD deposition chamber for improving gas distribution, comprising a deposition chamber body, the deposition chamber body having a top cover, a bowl-shaped baffle plate with an upward opening arranged in the deposition chamber body and at the lower end of the top cover, the bowl-shaped baffle plate and the top cover form a first gas mixing chamber, and a plurality of gas outlet holes are evenly distributed on the bowl-shaped baffle plate;

[0006] A truncated cone-shaped shell is provided in the first mixing chamber. The shell is a hollow structure and a second mixing chamber is formed in the shell. The air intake pipe is connected to the second mixing chamber. The side wall and the bottom of the shell are respectively provided with a diversion part, and the diversion part is provided with a diversion hole connected to the second mixing chamber.

[0007] Furthermore, the shell side wall has a plurality of diverter portions, and the plurality of diverter portions are evenly distributed along the circumference of the shell side wall.

[0008] Furthermore, there is at least one diversion portion at the bottom of the shell.

[0009] Furthermore, the top of the shell is the large end, and the bottom is the small end.

[0010] Furthermore, a connecting pipe penetrating the top cover is provided on the top of the shell, the connecting pipe is communicated with the second gas mixing chamber, and the air intake pipe is communicated with the connecting pipe.

[0011] Furthermore, a connecting rod is provided on the top of the shell, and the connecting rod is fixedly connected to the top cover.

[0012] The beneficial effects of the present application are as follows: 1. The present application sets a second gas mixing chamber so that the gas is first mixed in the second gas mixing chamber before entering the gas, and then enters the first gas mixing chamber through the diversion hole for a second mixing, thereby making the gas entering the deposition chamber evenly mixed, thereby avoiding the problem of uneven distribution of the plasma electric field and excessive carbon deposition in the middle area of ​​the molybdenum platform due to uneven mixing of the gas entering the deposition chamber.

[0013] 2. The gas in the first gas mixing chamber enters the deposition chamber through multiple outlet holes, so that the gas entering the deposition chamber through the outlet holes can be evenly distributed, avoiding uneven gas concentration in the deposition chamber, greatly improving the gas utilization efficiency, significantly improving the deposition quality, and thus improving the consistency of diamond crystal growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the structure of the utility model;

[0015] Figure 2 It is a structural schematic diagram of the housing of the utility model;

[0016] Figure 3 It is a structural schematic diagram of the prior art.

[0017] Markings in the figure: 1. Deposition chamber body, 11. Top cover, 12. Diamond growth reaction chamber, 2. Bowl-shaped baffle, 3. Shell, 31. Diverter part, 311. Diverter hole, 32. Connecting pipe, 33. Connecting rod, 4. Air inlet pipe. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that in the description of the utility model, unless otherwise specified, the meaning of "multiple" is two or more; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0019] See also Figure 1-2An embodiment of the utility model provides an MPCVD deposition chamber with improved gas distribution, including a deposition chamber body 1, the deposition chamber body 1 having a top cover portion 11, a bowl-shaped baffle 2 with an upward opening is provided in the deposition chamber body 1 and at the lower end of the top cover portion 11, the bowl-shaped baffle 2 and the top cover portion 11 form a first gas mixing chamber, a plurality of gas outlet holes 21 are evenly distributed on the bowl-shaped baffle 2, a shell 3 in the shape of a truncated cone is provided in the first gas mixing chamber, the shell 3 is a hollow structure and a second gas mixing chamber is formed in the shell 3, an air inlet pipe 4 is connected to the second gas mixing chamber, a diversion portion 31 is provided on the side wall and the bottom of the shell 3, respectively, and a diversion hole 311 connected to the second gas mixing chamber is provided on the diversion portion 31.

[0020] The deposition chamber body 1 also includes a deposition table and a molybdenum table located on the deposition table, both of which can adopt existing deposition tables and molybdenum tables. It should be noted that the parts not described in detail in this application are all prior arts.

[0021] Among them, combined Figure 1 and Figure 2 As shown, there are multiple diverter portions 31 on the side wall of the shell 3, and the multiple diverter portions 31 are evenly distributed along the circumference of the side wall of the shell 3. There is at least one diverter portion 31 at the bottom of the shell 3. In this embodiment, there is one diverter portion 31, the top of the shell 3 is the large end, and the bottom is the small end.

[0022] To further explain the present application, the differences between the prior art and the present application are introduced. The prior art is as follows: Figure 1 As shown, intermediate air intake is adopted to directly enter the interior of the deposition chamber, and the interior of the deposition chamber is entirely a reaction chamber. The present application divides the interior of the deposition chamber body 1 of the present application into a first mixing chamber and a diamond growth reaction chamber 12 by setting a bowl-shaped baffle 2. The deposition table and the molybdenum table are both located in the diamond growth reaction chamber 12.

[0023] Specifically, a connecting pipe 32 penetrating the top cover portion 11 is provided on the top of the shell 3, the connecting pipe 32 is connected to the second mixing chamber, the intake pipe 4 is connected to the connecting pipe 32, and a connecting rod 33 is provided on the top of the shell 3, the connecting rod 33 is fixedly connected to the top cover portion 11, the upper end of the connecting rod 33 is connected to the top cover portion 11, and the lower end is connected to the top of the shell 3. The stability of the connection between the shell 3 and the top cover portion 11 is ensured by setting the connecting rod 33.

[0024] The present application sets a second gas mixing chamber so that the gas is first mixed in the second gas mixing chamber before entering the gas, and then enters the first gas mixing chamber through the diversion hole 311 for a second mixing, and then enters the diamond growth reaction chamber 12 through the outlet hole 21, so that the gas entering the diamond growth reaction chamber 12 is evenly mixed, avoiding the problem of uneven plasma electric field distribution and excessive carbon deposition in the middle area of ​​the molybdenum platform due to uneven mixing of the gas entering the diamond growth reaction chamber 12.

[0025] Of course, the present invention is not limited to the above-described implementations. Several other implementations based on the design concept of the present invention are provided below.

[0026] For example, in other embodiments, different from the above-described embodiments, there are multiple, preferably four, diversion parts 31 at the bottom of the shell 3 , which are evenly distributed at the bottom of the shell 3 .

[0027] It should be noted that the above embodiments are only used to illustrate the present utility model, but the present utility model is not limited to the above embodiments. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present utility model fall within the protection scope of the present utility model.

Claims

1. An MPCVD deposition chamber with improved gas distribution, characterized in that: The deposition chamber body (1) comprises a deposition chamber body (1), the deposition chamber body (1) having a top cover (11), a bowl-shaped baffle (2) with an upward opening provided in the deposition chamber body (1) and at the lower end of the top cover (11), the bowl-shaped baffle (2) and the top cover (11) forming a first gas mixing chamber, and a plurality of gas outlet holes (21) evenly distributed on the bowl-shaped baffle (2); A shell (3) in the shape of a truncated cone is provided in the first gas mixing chamber, the shell (3) is a hollow structure and a second gas mixing chamber is formed in the shell (3), the air intake pipe (4) is in communication with the second gas mixing chamber, a flow dividing portion (31) is provided on the side wall and the bottom of the shell (3), and a flow dividing hole (311) in communication with the second gas mixing chamber is provided on the flow dividing portion (31).

2. The MPCVD deposition chamber with improved gas distribution according to claim 1, characterized in that: The side wall of the shell (3) has a plurality of flow dividing portions (31), and the plurality of flow dividing portions (31) are evenly distributed along the circumference of the side wall of the shell (3).

3. The MPCVD deposition chamber with improved gas distribution according to claim 1, characterized in that: There is at least one flow diversion portion (31) at the bottom of the shell (3).

4. The MPCVD deposition chamber with improved gas distribution according to claim 1, characterized in that: The top of the shell (3) is the large end, and the bottom is the small end.

5. The MPCVD deposition chamber with improved gas distribution according to claim 1, characterized in that: A connecting pipe (32) penetrating the top cover portion (11) is provided on the top of the shell (3); the connecting pipe (32) is in communication with the second gas mixing chamber; and the air intake pipe (4) is in communication with the connecting pipe (32).

6. The MPCVD deposition chamber with improved gas distribution according to claim 5, characterized in that: A connecting rod (33) is provided on the top of the housing (3), and the connecting rod (33) is fixedly connected to the top cover (11).

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