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CN-121989155-A - Method for treating inner surface of stainless steel air pipe assembly for semiconductor

CN121989155ACN 121989155 ACN121989155 ACN 121989155ACN-121989155-A

Abstract

The invention discloses a method for treating the inner surface of a stainless steel air pipe assembly for a semiconductor, which comprises the following steps of firstly, pretreating the inner surface of the stainless steel air pipe assembly through a foundation to enable the surface roughness of the inner surface of the stainless steel air pipe assembly to reach the precision capable of being finished, secondly, mechanically polishing the inner surface of the stainless steel air pipe assembly through multiple stages by using an abrasive with gradually reduced granularity to enable the roughness of the inner surface of the stainless steel air pipe assembly to reach the target precision, and thirdly, treating the inner surface of the stainless steel air pipe assembly through electrolytic polishing to generate a passivation film with high precision on the inner surface of the stainless steel air pipe assembly. By the mode, the method can effectively improve the smoothness and corrosion resistance of the inner surface of the stainless steel gas pipe assembly, not only improves the whole service life of the pipeline, but also remarkably reduces the influence of the pipeline on high-purity gas, and meets the harsh requirement of semiconductor tip process on the gas purity.

Inventors

  • XIAO MING

Assignees

  • 常熟市兆恒众力精密机械有限公司

Dates

Publication Date
20260508
Application Date
20260206

Claims (10)

  1. 1. The inner surface treatment method of the stainless steel gas pipe assembly for the semiconductor is characterized by comprising the following steps of: Firstly, preprocessing the inner surface of the stainless steel air pipe assembly through a foundation to ensure that the surface roughness of the inner surface reaches the precision capable of carrying out finish machining; Secondly, carrying out multistage mechanical polishing by using an abrasive with granularity reduced step by step, so that the roughness of the inner surface of the stainless steel air pipe assembly reaches corresponding target precision; And thirdly, treating the inner surface of the stainless steel air pipe assembly by electrolytic polishing to generate a high-precision passivation film on the inner surface of the stainless steel air pipe assembly.
  2. 2. The method for treating the inner surface of a stainless steel tracheal assembly for semiconductors according to claim 1, wherein the precision after the basic pretreatment in the first step is that the surface roughness reaches ra0.1.
  3. 3. The method for treating the inner surface of a stainless steel tracheal assembly for semiconductor according to claim 1, wherein the target precision in the second step is that the surface roughness reaches to ra0.05 μm.
  4. 4. The method for treating the inner surface of the stainless steel gas pipe assembly for the semiconductor according to claim 1, wherein the stainless steel gas pipe assembly comprises standard components such as an EP pipe, a standard valve and a standard joint which are made of 316L materials, the inner surface of the standard component is subjected to electrolytic polishing treatment in advance, and the precision of the inner surface after the electrolytic polishing treatment is smaller than the requirement of the preprocessing precision.
  5. 5. The method of claim 1, wherein the stainless steel gas pipe assembly comprises a non-standard workpiece, and the non-standard workpiece is processed by fluid polishing before being processed, so that the roughness of the inner surface of the non-standard workpiece is accurate for finish machining.
  6. 6. The method of treating an inner surface of a stainless steel tracheal assembly for a semiconductor according to claim 1, wherein the multi-stage mechanical polishing comprises four stages including: Firstly, sleeving 1000-mesh waterproof abrasive paper on a pneumatic pen to polish the inner surface of a corresponding stainless steel air pipe assembly at one stage, then, replacing the 1000-mesh waterproof abrasive paper on the pneumatic pen with 1500-mesh waterproof abrasive paper to polish at the second stage, eliminating scratches left by the previous stage of polishing, replacing the 1500-mesh waterproof abrasive paper on the pneumatic pen with 2000-mesh waterproof abrasive paper to polish at the third stage, polishing at the third stage, and finally, using a wool grinding head to polish the inner surface in a mirror surface in a matching manner, so that the roughness of the inner surface meets the technological requirements.
  7. 7. The method for treating the inner surface of a stainless steel tracheal assembly for a semiconductor according to claim 6, wherein the primary polishing, secondary polishing and tertiary polishing are performed at a speed of not more than 5 min/m.
  8. 8. The method for treating the inner surface of a stainless steel tracheal assembly for a semiconductor according to claim 6, wherein the speed of the mirror polishing is not more than 5s/cm.
  9. 9. The method of treating the inner surface of a stainless steel tracheal assembly for semiconductors according to claim 6, wherein the polishing paste is a diamond paste having a particle size of not more than 3.5.
  10. 10. The method for treating the inner surface of a stainless steel tracheal assembly for semiconductors according to claim 1, wherein the electrolytic polishing is performed by using a phosphoric acid-sulfuric acid system electrolyte.

Description

Method for treating inner surface of stainless steel air pipe assembly for semiconductor Technical Field The invention relates to the field of semiconductor production equipment, in particular to a method for treating the inner surface of a stainless steel air pipe component for a semiconductor. Background In the field of semiconductor production such as chips, the purity of a process gas medium is directly related to the yield and performance stability of the product, while a stainless steel gas pipe assembly is used as a component part of a process medium conveying pipeline, and the quality of the inner surface of the stainless steel gas pipe assembly directly influences the purity of high-purity gas entering an operation area. The reason is that a certain amount of gas is adsorbed in the metal lattice during smelting and processing of the stainless steel material, when high-purity gas flows through the pipeline, the adsorbed gas can be dissociated again into the gas flow for pollution because of molecular movement parts, particularly, under the working condition of discontinuous processing of the gas, the inner wall of the pipeline can be periodically adsorbed and analyzed due to pressure change, the process can release impurity gas, and micro powder can be generated on the metal of the inner wall under the long-term action, so that particle pollutants are formed. Therefore, in order to minimize gas pollution and particulate generation, the inner surface of the pipe is required to have not only extremely high smoothness, i.e., extremely low surface roughness, in order to reduce the fluid micro-vortex impact and specific surface area, but also excellent chemical stability and wear resistance in the semiconductor manufacturing process. In the current industry, a 316L stainless steel pipe (EP pipe), a standard valve, a joint and other pipeline standard components which are subjected to electrolytic polishing are generally used for constructing a gas pipeline, and the roughness of the inner surface of the pipeline standard components can be controlled within 0.1 mu m generally due to the characteristic of electrolytic polishing, so that the conventional cleaning requirement can be basically met. However, there are many nonstandard parts such as elbows, tees, cavity joints, etc. on the gas pipeline, which cannot directly use standard EP pipes, and the surface of the inner wall is often poor in roughness due to the limitation of the process conditions of nonstandard machining, and Ra 0.4 μm or higher can be usually only achieved. To achieve these non-standard parts with clean requirements, the prior art has typically used a "fluid polishing + electropolishing" two-step process. In this way, the roughness can be controlled to within Ra 0.1. Mu.m. However, the method can only meet the cleanliness requirement of general semiconductor production within the scale of roughness Ra 0.1 μm, for some tip semiconductor production, the control of the process environment is more severe, the precision is far insufficient, the roughness is controlled only by electrolytic polishing, the limit is Ra 0.1 μm, while the fluid polishing can improve the macroscopic finish of a substrate with a complex inner cavity, but the final surface roughness is limited, the bottleneck of Ra 0.1 μm is difficult to break through, the overall finish of the surface cannot be further improved by the superposition electrolytic polishing process, and the extreme requirement of the increasingly-improved tip semiconductor process on the gas purity cannot be met. Disclosure of Invention The invention mainly solves the technical problem of providing a method for treating the inner surface of a stainless steel gas pipe component for a semiconductor, which can meet the requirement of a tip semiconductor process on gas purity. In order to solve the technical problems, the technical scheme adopted by the invention is that the inner surface treatment method of the stainless steel air pipe component for the semiconductor comprises the following steps of: Firstly, preprocessing the inner surface of the stainless steel air pipe assembly through a foundation to ensure that the surface roughness of the inner surface reaches the precision capable of carrying out finish machining; Secondly, carrying out multistage mechanical polishing by using an abrasive with gradually reduced granularity, so that the roughness of the inner surface of the stainless steel air pipe assembly reaches the target precision; And thirdly, treating the inner surface of the stainless steel air pipe assembly by electrolytic polishing to generate a high-precision passivation film on the inner surface of the stainless steel air pipe assembly. In a preferred embodiment of the present invention, the precision after the basic pretreatment in the first step is that the surface roughness reaches Ra0.1. In a preferred embodiment of the present invention, the target precision in the second step is tha