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CN-121976173-A - Low-pressure reaction cavity air inlet device, deposition reaction cavity and uniform air supply method

CN121976173ACN 121976173 ACN121976173 ACN 121976173ACN-121976173-A

Abstract

The invention discloses a low-pressure reaction cavity air inlet device, a deposition reaction cavity and a uniform air supply method, and relates to the technical field of low-pressure hot wire chemical vapor deposition reaction equipment. The top plate of the first area distribution cavity is provided with an air inlet, a flow dispersing cap with an opening at the upper end and a closing lower end is inserted in the air inlet, a flow dispersing hole is formed in the peripheral surface of the flow dispersing cap, and the lower plate of the first area distribution cavity is a flow limiting piece provided with a hole array. The diffuser cap cooperates with the flow restrictor to diffuse the concentrated intake air and establish a dominant pressure drop in the first zone. And the gas enters the flow equalizing cavity of the second area to perform pressure equalization, and finally is sprayed downwards through the uniform gas outlet surface at the bottom. The invention realizes a distribution mechanism leading by pressure drop in the device by constructing a cascade structure of diffusion, pressure stabilization and pressure equalization, isolates upstream and downstream process fluctuation, and ensures uniformity, stability and high repeatability of air flow supplied to a reaction cavity base station area.

Inventors

  • LI KAI
  • CHEN CHAO
  • Mo Luozhi
  • WANG PEIXUN
  • JIANG SHIWEI
  • Mo Peicheng
  • ZHANG JUN
  • CHEN JIARONG
  • PAN XIAOYI

Assignees

  • 中国有色桂林矿产地质研究院有限公司

Dates

Publication Date
20260505
Application Date
20260226

Claims (10)

  1. 1. A low pressure reaction chamber air inlet device, comprising: The device comprises a cylindrical first area distribution cavity (1) and a second area flow equalizing cavity (2), wherein the first area distribution cavity (1) is positioned above the second area flow equalizing cavity (2), and the two areas are in fluid communication to form a sequentially pressure-stabilizing double-cavity structure; An air inlet (3) for connecting an external air source is formed in the middle of the top plate of the first area distribution cavity (1); The dispersing cap (4) is inserted into and fixed at the tail end of the air inlet (3), the dispersing cap (4) is of a cylindrical structure with an opening upper end and a closed lower end, and a plurality of dispersing holes (41) are formed in the circumferential wall surface of the lower end of the dispersing cap to be communicated with the first area distribution cavity (1) and used for dispersing concentrated air flow from the air inlet (3) and converting the concentrated air flow into radial diffusion; A flow restrictor (5) forming a lower plate of the first zone distribution chamber (1), the flow restrictor (5) being provided with a first array of holes (51) for establishing a controlled dominant pressure drop in the first zone distribution chamber (1) in cooperation with the diffuser cap (4); The bottom of the second area flow equalizing cavity (2) is provided with an air outlet surface (6), and the air outlet surface (6) is provided with a second hole array (61) for converting uniform pressure from the second area flow equalizing cavity (2) into downward-spraying uniform air flow.
  2. 2. The low pressure reaction chamber air inlet device according to claim 1, wherein the flow dispersing cap (4) is cylindrical, has an outer diameter of 18-35mm and a length of 40-80mm, and the flow dispersing holes (41) have a pore diameter of 1-2mm and are distributed in a plurality of rows and staggered on the peripheral surface of the flow dispersing cap (4).
  3. 3. The low-pressure reaction chamber air inlet device according to claim 1, wherein the first area distribution chamber (1) is a flat cylindrical chamber with a chamber height of 30-35mm and a diameter of 300-400mm.
  4. 4. The low pressure reaction chamber air inlet device according to claim 1, wherein the total opening ratio of the first hole array (51) on the flow limiting piece (5) is 10% -20%.
  5. 5. The low-pressure reaction chamber air inlet device according to claim 1, wherein the second area flow equalizing chamber (2) is a disc-shaped chamber with a chamber height of 15-25mm and a diameter of 300-400mm.
  6. 6. The low pressure reaction chamber air inlet device according to claim 1, wherein the aperture of the second hole array (61) on the air outlet surface (6) is 3-5mm, and the total aperture ratio is 20% -30%.
  7. 7. The low-pressure reaction chamber air inlet device according to claim 1, wherein the air inlet (3) is provided with internal threads and is used for being in sealing connection with a hollow stud with external threads, so that the detachable installation of the reaction chamber top cover is realized.
  8. 8. The low pressure reaction chamber inlet device of claim 1 wherein all of the gas contacting components of the device are made of stainless steel material.
  9. 9. A low-pressure hot filament chemical vapor deposition reaction chamber, characterized by comprising an air inlet device as claimed in any one of claims 1-8, wherein the air inlet device is installed in the center of a top cover of the reaction chamber in a sealing manner, and the air outlet surface (6) is arranged towards a base station in the reaction chamber.
  10. 10. A method of achieving uniform air supply using the air intake apparatus according to any one of claims 1 to 8, comprising: Process gas enters the diffusion cap (4) from the gas inlet (3); the gas is sprayed and diffused through the diffusing holes (41) of the diffusing cap (4) and enters the containing cavity space of the first area distribution cavity (1), and the concentrated kinetic energy is dissipated; The diffused gas flows through a first hole array (51) of the flow limiting piece (5), a first-stage leading pressure drop is generated at the first hole array, and primary pressure stabilization and distribution are completed; The gas enters the second area flow equalizing cavity (2), and the full pressure self-equalization is carried out in the large-volume cavity, so that the local pressure difference is eliminated; The gas with balanced pressure is uniformly sprayed downwards through the second hole array (61) of the gas outlet surface (6) to form a stable and uniform gas flow field covering the working area of the base station.

Description

Low-pressure reaction cavity air inlet device, deposition reaction cavity and uniform air supply method Technical Field The invention relates to the technical field of low-pressure hot filament chemical vapor deposition reaction equipment, in particular to a low-pressure reaction cavity air inlet device, a deposition reaction cavity and a uniform air supply method. Background In low pressure, large diameter vacuum process equipment, such as Hot Filament Chemical Vapor Deposition (HFCVD) reaction chambers, how to provide a uniform, stable and repeatable supply of reactant gases to the platen working area is a key technical challenge to ensure uniformity of film deposition quality. The reaction chamber operating pressure is typically in the low pressure region of 0.5 to 20 kPa and the gas momentum density is low, making the gas flow distribution extremely susceptible to disturbance. In the prior art, a common top air inlet scheme mainly comprises a central point spraying type, a single-cavity annular wall surface air inlet type, a porous panel type and the like. These solutions have inherent drawbacks in that the central point jet type intake momentum is too concentrated, resulting in serious uneven air flow distribution in the base surface, and in that the single-chamber annular or porous panel type intake attempts to achieve surface distribution, but the uniformity of air flow distribution is essentially dominated by the pressure distribution formed in the single chamber by the upstream air supply pipeline, or is controlled by the downstream air extraction load due to insufficient outlet pressure drop. In other words, the internal flow field of the existing air inlet device lacks self-regulation and stabilization capability, and the air outlet uniformity is extremely sensitive to external conditions (such as air source pressure fluctuation, flow change and air extraction non-uniformity), so that the process repeatability is poor, and a dead zone with insufficient air supply is easily formed above the base station. Accordingly, there is a need in the art for an air intake device that is structurally capable of achieving an inherently stable and uniform distribution of air flow that is insensitive to fluctuations in upstream and downstream boundary conditions. Disclosure of Invention The invention aims to provide a low-pressure reaction chamber air inlet device, a deposition reaction chamber and a uniform air supply method, so as to solve the problems in the prior art and realize the internal stable and uniform distribution of air flow structurally. In order to achieve the above object, the present invention provides the following solutions: A low pressure reaction chamber inlet arrangement comprising: The first area distribution cavity is positioned above the second area flow equalizing cavity, and the first area distribution cavity and the second area flow equalizing cavity are in fluid communication to form a sequentially pressure-stabilizing double-cavity structure; an air inlet used for being connected with an external air source is formed in the middle of the top plate of the first area distribution cavity; The dispersing cap is inserted into and fixed at the tail end of the air inlet, is of a cylindrical structure with an opening upper end and a closed lower end, and is provided with a plurality of dispersing holes on the circumferential wall surface of the lower end so as to be communicated with the first area distribution cavity and used for dispersing concentrated air flow from the air inlet and converting the concentrated air flow into radial diffusion; A flow limiting piece forming a lower plate of the first area distribution cavity, wherein a first hole array is arranged on the flow limiting piece and used for establishing controlled dominant pressure drop in the first area distribution cavity in cooperation with the flow dispersing cap; the bottom of the second area flow equalizing cavity is provided with an air outlet surface, and the air outlet surface is provided with a second hole array for converting uniform pressure from the second area flow equalizing cavity into downward-sprayed uniform air flow. In an exemplary embodiment, the diffuser cap is cylindrical, has an outer diameter of 18-35mm and a length of 40-80mm, and the diffuser holes have a diameter of 1-2mm and are distributed in multiple rows and staggered on the peripheral surface of the diffuser cap. In an exemplary embodiment, the first zone distribution chamber is a flat cylindrical chamber having a chamber height of 30-35mm and a diameter of 300-400mm. In an exemplary embodiment, the total aperture ratio of the first aperture array on the flow restrictor is 10% -20%. In an exemplary embodiment, the second zone flow equalizing cavity is a disk-shaped cavity having a cavity height of 15-25mm and a diameter of 300-400mm. In an exemplary embodiment, the aperture of the second hole array on the air outlet surface is 3-5mm, and the to