| 引用本文: | 刘万锁,岳向吉,蔺增.PECVD喷淋板上微通道结构对射流均匀性的影响性分析[J].中国表面工程,2023,36(5):222~233 |
| LIU Wansuo,YUE Xiangji,LIN Zeng.Analysis of Microchannel Structure on Jet Uniformity of PECVD Showerhead[J].China Surface Engineering,2023,36(5):222~233 |
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| 摘要: |
| 喷淋板微通道结构对等离子体增强化学气相沉积镀膜工艺成膜均匀性具有重要影响，目前缺少对不同微通道差异性的研究。通过采用滑移边界修正的连续流计算方法，获得克努森数为 0.009~0.01 的微通道流动特性结果，计算结果与其他微通道试验与计算结果具有一致性。结果表明，等径型与收缩型微通道几何尺寸对均匀性影响较小，出口射流所形成的涡流会降低均匀性，扩张型微通道提高出口扩散性，其射流均匀性明显优于前两者。通过提出均匀性量化方法，研究等径型、收缩型和扩张型三种具有代表性的微通道结构，进一步完善了喷淋板及稀薄环境微通道研究的不足。 |
| 关键词: 微通道 射流均匀性 均匀性量化 扩张腔 等离子体增强化学气相沉积(PECVD) |
| DOI：10.11933/j.issn.1007?9289.20221202001 |
| 分类号:O356 |
| 基金项目: |
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| Analysis of Microchannel Structure on Jet Uniformity of PECVD Showerhead |
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LIU Wansuo1, YUE Xiangji1, LIN Zeng1,2
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1.School of Mechanical Engineering and Automation, Northeast University, Shenyang 110819 , China;2.Research Center of Vacuum Coating Technology of Shenyang, Shenyang 110819 , China
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| Abstract: |
| Plasma-enhanced chemical vapor deposition(PECVD) is an important thin-film manufacturing process for semiconductors. In PECVD, a chemical reaction occurs between the ionized reaction gas and ion state, and the plasma is driven through a bias electric field to achieve the final thin film deposition. The uniformity of the gas in this process significantly affects the uniformity of the chemical reaction in the reactor, which in turn affects the quality of the film. Therefore, incorporating a showerhead is necessary to homogenize the gas, and the corresponding homogenization performance is determined by the structural characteristics of the microchannels. Currently, there are few studies on such microchannels, and systematic evaluation of the differences between various microchannels has not been performed. Based on research in the field of microchannels in rarefied environments, research on the uniformity of microchannel jets has been extended. In simulating the three-dimensional structure, a continuous flow calculation method with slip boundary correction and a hexahedral grid structure were employed to analyze the flow field of a microchannel with a circular section of variable diameter, and the flow properties of the microchannel with a Knudsen number of 0.009 1–0.010 9 were obtained. The diameter of the equal-diameter-type microchannel is 0.8 mm and the length is 8 mm. The calculated results are consistent with the experimental and calculated results for the other microchannels. Owing to the lack of measurement methods for jet uniformity, those of different regions or velocities cannot be compared. Therefore, a quantification method and standard for jet uniformity are proposed to distinguish between uniform, nonuniform, and sub-uniform jets. This allows simple comparison of sub-uniform jets, as well as various jet uniformities, by integration. Based on the quantitative method of jet flow uniformity, the flow characteristics of representative expansionary, contractile, and equal-diameter microchannels were analyzed, and the effects of constricting and expanding cavities on the flow field were studied. The development process of the flow field in different microchannels was analyzed using a transient calculation method to determine the cause of the change in jet uniformity in different microchannels. The differences in the jet uniformity of expansion cavities of different sizes were compared and analyzed, and the principle of the influence of the expansion cavity geometry on fluid diffusion was determined. The results show that, compared with the equal-diameter- and contractile-type microchannels, the jet uniformity in expansionary-type microchannels clearly changes with the geometry. When the length and diameter of the equal-diameter- and contractile-type microchannels were varied, there was no significant difference in the uniformity of the jet flow. When the taper of the expansionary type is too large, the characteristics of the expansion cavity are lost, reducing the uniformity. Expansionary-type microchannels have better diffusivity, and thus the corresponding jet uniformity is better than that in equal-diameter- and contractile-type microchannels. Nevertheless, the vortex formed by the jet has a negative effect on uniformity. The outlet positions of the equal-diameter- and contractile-type microchannels formed a vortex that hindered fluid diffusion. Similarly, when the taper of the expansionary type is too large, a vortex forms in the expansion cavity, which reduces the jet uniformity. |
| Key words: microchannel jet uniformity uniformity quantification expansion cavity plasma-enhanced chemical vapor deposition(PECVD) |
