大尺寸方形载板MOCVD反应腔分气和薄膜沉积过程影响因素的数值模拟研究*

doi:10.13385/j.cnki.vacuum.2024.02.04

摘要/Abstract

摘要： 介绍了适用于光伏行业砷化镓（GaAs）薄膜电池制备所需的大尺寸方形载板金属有机化学气相沉积（MOCVD）反应腔的多级分气系统,以及该反应腔结构设计过程中的核心参数：喷淋盘孔尺寸、载板与喷淋盘间距（简称“腔室间距”）。基于自研的容量为36×4寸的MOCVD反应腔模型,应用计算流体力学（CFD）方法,同时考虑GaAs沉积过程中的气相反应和表面反应,对不同孔参数和腔室间距时的气流分配和薄膜化学气相沉积过程进行了数值模拟。考察了跨孔压差与气流量分配均匀性的关系,以及腔室间距对反应区气体流动以及GaAs薄膜沉积的影响。结果表明：初级“蜘蛛”形分气盘将主进气口分配成64个子进气口后的分气均匀性较好,质量流量值波动幅度仅为0.22%;增加喷淋盘孔深度可缓慢且线性提高孔压差,而缩小孔径对于压差的增加非常迅速;增加喷淋盘孔压差可提高次级分气均匀性,但提升效果趋缓;大腔室间距下的沉积速率低,且均匀性差;随着腔室间距缩小,沉积速率持续增加的同时,沉积均匀性先变好,后逐渐由于气流震荡而变差。

关键词: 金属有机化学气相沉积, 砷化镓, 数值模拟, 气体分配

Abstract: The multistage gas distribution system of large-sized square carrier metal-organic chemical vapor deposition (MOCVD) for the preparation of gallium arsenide (GaAs) thin film in the photovoltaic industry is introduced. The core parameters in the design process of the reactor structure, such as the size of the showerhead hole and the spacing between the showerhead and carrier (chamber spacing) are discussed. Based on a self-developed MOCVD reactor model with a carrier of 36×4 inches wafers, the computational fluid dynamics (CFD) method and the gas reaction and surface reaction during GaAs film deposition were used to simulate the gas distribution and chemical vapor deposition (CVD) process with different parameters and chamber spacing. The relationship between cross-orifice pressure difference and gas flow distribution uniformity, and the effect of chamber spacing on gas flow and GaAs film deposition were investigated. The results show that after the primary "spider" plate divides the main gas inlet into 64 sub-gas intakes, the gas distribution uniformity is better, and the fluctuation amplitude of mass flow rate value is only 0.22%. Increasing the hole depth of the showerhead increases the hole pressure difference slowly and linearly, while reducing the hole diameter increases the pressure difference very quickly. Increasing the hole pressure difference of the showerhead can improve the uniformity of secondary gas separation, but the lifting effect is slow. The deposition rate is low and the uniformity is poor at large chamber spacing. With the decreasing of the spacing and the increasing of deposition rate, the deposition uniformity becomes better at first, and then becomes worse gradually due to the turbulence of gas flow.

Key words: MOCVD, GaAs, numerical simulation, gas distribution

中图分类号: TK72;TB43

于大洋, 吴改. 大尺寸方形载板MOCVD反应腔分气和薄膜沉积过程影响因素的数值模拟研究^*[J]. 真空, 2024, 61(2): 22-28.

YU Da-yang, WU Gai. Numerical Simulation of the Influence of Gas Distribution and Film Deposition Process in MOCVD Reactor with Large-sized Square Carrier[J]. VACUUM, 2024, 61(2): 22-28.

参考文献

[1] KNECHTLI R C, LOO R Y, KAMATH G S.High-efficiency GaAs solar cells[J]. IEEE Transactions on Electron Devices, 1984, 31(5): 577-588.
[2] CHOW T P, OMURA I, HIGASHIWAKI M, et al.Smart power devices and ICs using GaAs and wide and extreme bandgap semiconductors[J]. IEEE Transactions on Electron Devices. 2017, 64(3): 856-873.
[3] SAHIN D, GAGGERO A, WEBER J W, et al.Waveguide nanowire superconducting single-photon detectors fabricated on GaAs and the study of their optical properties[J]. IEEE Journal of Selected Topics in Quantum Electronics, 2015, 21(2): 3800210.
[4] MOON S, KIM K, KIM Y, et al.Highly efficient single-junction GaAs thin-film solar cell on flexible substrate[J]. Scientific Reports, 2016, 6(1): 30107.
[5] AL-EZZI A S, ANSARI M N M. Photovoltaic solar cells: a review[J]. Applied System Innovation, 2022, 5(4): 67.
[6] MASSIOT I, CATTONI A, COLLIN S.Progress and prospects for ultrathin solar cells[J]. Nature Energy, 2020, 5(12): 959-972.
[7] 徐楠, 左然, 何晓焜, 等. 垂直转盘式MOCVD反应器中GaN化学反应路径的影响研究[J]. 人工晶体学报, 2012, 41(4): 1007-1112.
[8] 于海群, 左然, 陈景升. 一种多喷淋头式MOCVD反应器的设计与数值模拟[J]. 人工晶体学报, 2011, 40(4): 1065-1071.
[9] 徐谦, 左然, 张红. MOCVD生长GaN的反应动力学分析与数值模拟[J]. 化工学报, 2009, 60(2): 384-388.
[10] TSAI M L, FANG C C, LEE L Y.Numerical simulation of the temperature distribution in a planetary MOCVD reactor[J]. Chemical Engineering and Processing, 2014, 81: 48-58.
[11] MIHOPOULOS T G, HUMMEL S G, JENSEN K F.Simulation of flow and growth phenomena in a close-spaced reactor[J]. Journal of Crystal Growth, 1998, 195(1-4): 725-732.
[12] MITROVIC B, PAREKH A, RAMER J, et al.Reactor design optimization based on 3D modeling of nitrides deposition in MOCVD vertical rotating disc reactors[J]. Journal of Crystal Growth, 2006, 289(2): 708-714.
[13] YU D Y, LI H.Numerical simulation of thermal performance of GaAs-metal-organic chemical vapor deposition reactor based on 36 × 4 inches' wafers[J]. Crystal Research and Technology, 2022, 57(5): 2100185.
[14] YU D Y, SHEN S N, LI H, et al.Design optimization of gas distribution system for large-scale capacity GaAs-MOCVD[J]. Crystal Research and Technology, 2023, 58(11): 2300186.
[15] MAZUMDAR S, LOWRY S A.The importance of predicting rate-limited growth for accurate modeling of commercial MOCVD reactors[J]. Journal of Crystal Growth, 2001, 224(1/2): 165-174.
[16] REID R C, PRAUSNITZ J M, POLING B E.The properties of gases and liquids[M]. United States: McGraw-Hill Book Company, 1987: 586.
[17] FERON O, SUGIYAMA M, ASWAMETHAPANT W, et al. MOCVD of InGaAsP, InGaAs and InGaP over InP and GaAs substrates: distribution of composition and growth rate in a horizontal reactor[J]. Applied Surface Science, 2000, 159/160: 318-327.
[18] SUGIYAMA M, KUSUNOKI K, SHIMOGAKI Y, et al. Kinetic studies on thermal decomposition of MOVPE sources using fourier transform infrared spectroscopy[J]. Applied Surface Science, 1997, 117/118: 746-752.
[19] MOUNTZIARIS T J, JENSEN K F.Gas-phase and surface reaction mechanisms in MOCVD of GaAs with trimethyl-gallium and arsine[J]. Journal of the Electrochemical Society, 1991, 138(8): 2426-2439.
[20] MITROVIC B, GURARY A, QUINN W.Process conditions optimization for the maximum deposition rate and uniformity in vertical rotating disc MOCVD reactors based on CFD modeling[J]. Journal of Crystal Growth, 2007, 303(1): 323-329.
[21] YANG C C, CHI G C, HUANG C K, et al.The improvement of GaN epitaxial layer quality by the design of reactor chamber spacing[J]. Journal of Crystal Growth, 1999, 200(1/2): 32-38.

Metrics

Viewed

Full text

Abstract

Cited

Shared

Discussed