喷淋式MOCVD反应器中AlN的生长速率和化学反应路径的数值模拟研究

人工晶体学报 ›› 2021, Vol. 50 ›› Issue (6): 1002-1009.

喷淋式MOCVD反应器中AlN的生长速率和化学反应路径的数值模拟研究

万旭, 左然

江苏大学能源与动力工程学院,镇江 212013

收稿日期:2021-04-12 出版日期:2021-06-15 发布日期:2021-07-08
通讯作者: 左然,博士,教授。E-mail:rzuo@ujs.edu.cn
作者简介:万旭(1995—),女,江苏省人,硕士研究生。E-mail:871022419@qq.com
基金资助:
国家自然科学基金(61474058)

Numerical Simulation Study on Growth Rate and Gas Reaction Path of AlN-MOCVD with Close-Coupled Showerhead Reactor

WAN Xu, ZUO Ran

School of Energy and Power Engineering, Jiangsu University, Zhenjiang 212013, China

Received:2021-04-12 Online:2021-06-15 Published:2021-07-08

摘要/Abstract

摘要： 利用数值模拟方法,结合反应动力学和气体输运过程,研究喷淋式MOCVD反应器中AlN的生长速率和气相反应路径与反应前体流量(NH₃和 H₂)、进口温度、压强、腔室高度等参数的关系。研究发现:薄膜生长前体和纳米粒子前体的浓度决定了不同的生长速率和气相反应路径。在低Ⅴ/Ⅲ比(2 000)、高H₂流量(12 L/min)、高进口温度(700 K)、低压强(2 kPa)、低腔室高度(5 mm)等条件下,气相反应路径由加合路径和热解路径并存,生长速率较高。反之,化学反应路径则由加合路径主导,生长速率较低。上述参数对反应路径的影响原因包括:气体流量(NH₃和H₂)较大,反应前体被带出生长区域或被稀释;低压强和低腔室高度使粒子碰撞频率降低、驻留时间缩短,进而削弱了寄生反应;进口温度导致温度梯度的变化。

关键词: MOCVD, AlN, 喷淋式反应器, 气相反应, 数值模拟

Abstract: By numerical simulation and combining reaction kinetics and gas transport process, the effects of gas flow rate (NH₃ and H₂), inlet temperature, pressure and chamber height on the growth rate and gas reaction path of AlN-MOCVD with close-coupled showerhead reactor were studied. It is found that the concentrations of AlN film precursor and nanoparticle precursor determine the growth rate and the gas reaction path. Under the conditions of low Ⅴ/Ⅲ ratio(2 000), high H₂ flow rate (12 L/min), high inlet temperature(700 K), low pressure(2 kPa) and low chamber height(5 mm), the reaction is dominated by both the adduct path and the pyrolysis path, and the growth rate is relatively high. On the contrary conditions, the reaction is dominated by the adduct path and the growth rate is rather low. There are different reasons for the effects of the above parameters on the reaction path, such as, the high NH₃ flow rate brings the precursor out of the growth zone and the high H₂ flow dilutes the reaction precursors in the growing region; the low pressure and low chamber height reduce the particle collision frequency and residence time, and weaken the parasitic response; the inlet temperature causes a change in the temperature gradient.

Key words: MOCVD, AlN, close-coupled showerhead reactor, gas reaction, numerical simulation

中图分类号:

O782
TQ11

万旭, 左然. 喷淋式MOCVD反应器中AlN的生长速率和化学反应路径的数值模拟研究[J]. 人工晶体学报, 2021, 50(6): 1002-1009.

WAN Xu, ZUO Ran. Numerical Simulation Study on Growth Rate and Gas Reaction Path of AlN-MOCVD with Close-Coupled Showerhead Reactor[J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(6): 1002-1009.

参考文献

[1] 陆大成,段树坤.金属有机化合物气相外延基础及应用[M].北京:科学出版社,2009.
LU D C, DUAN S K.Fundamentals and applications of metal organic compounds vapor phase epitaxy[M].Beijing:Science Press, 2009(in Chinese).
[2] 张莲,张红,左然.MOVPE生长AlN的气相反应机理的密度泛函理论研究[J].人工晶体学报,2018,47(3):481-488.
ZHANG L, ZHANG H, ZUO R.Density functional theory study on gas reaction mechanism in AlN MOVPE[J].Journal of Synthetic Crystals, 2018, 47(3):481-488(in Chinese).
[3] LI S L, WANG H, ZHANG J, et al.The effects of growth temperature of the pulse atomic layer epitaxy AlN films grown on sapphire by MOCVD[J].Proceedings of SPIE - The International Society for Optical Engineering, 2011, 8333:52.
[4] KELLER S, DENBAARS S P.Metalorganic chemical vapor deposition of group Ⅲ nitrides—a discussion of critical issues[J].Journal of Crystal Growth, 2003, 248:479-486.
[5] MIHOPOULOS T G, GUPTA V, JENSEN K F.A reaction-transport model for AlGaN MOVPE growth[J].Journal of Crystal Growth, 1998, 195(1/2/3/4):733-739.
[6] DADGAR A, KROST A, CHRISTEN J, et al.MOVPE growth of high-quality AlN[J].Journal of Crystal Growth, 2006, 297(2):306-310.
[7] STELLMACH J, PRISTOVSEK M, SAVŞ Ö, et al.High aluminium content and high growth rates of AlGaN in a close-coupled showerhead MOVPE reactor[J].Journal of Crystal Growth, 2011, 315(1):229-232.
[8] LOBANOVA A V, MAZAEV K M, TALALAEV R A, et al.Effect of Ⅴ/Ⅲ ratio in AlN and AlGaN MOVPE[J].Journal of Crystal Growth, 2006, 287(2):601-604.
[9] ZHAO D G, ZHU J J, JIANG D S, et al.Parasitic reaction and its effect on the growth rate of AlN by metalorganic chemical vapor deposition[J].Journal of Crystal Growth, 2006, 289(1):72-75.
[10] INAGAKI Y, KOZAWA T.Chemical reaction pathways for MOVPE growth of aluminum nitride[J].ECS Journal of Solid State Science and Technology, 2015, 5(2):P73-P75.
[11] WU H L, ZHAO W, HE C G, et al.Growth of high quality AlN/sapphire templates with high growth rate using a medium-temperature layer[J].Superlattices and Microstructures, 2019, 125:343-347.
[12] 茅艳琳,左然.行星式MOCVD反应器进口结构对AlN生长的气相反应和生长速率的影响[J].人工晶体学报,2020,49(7):1168-1175.
MAO Y L, ZUO R.Influence of inlet structure of planetary reactor on gas reaction path and growth rate in AlN-MOCVD[J].Journal of Synthetic Crystals, 2020, 49(7):1168-1175(in Chinese).
[13] CHOI S C, KIM J H, CHOI J Y, et al.Al concentration control of epitaxial AlGaN alloys and interface control of GaN/AlGaN quantum well structures[J].Journal of Applied Physics, 2000, 87(1):172-176.
[14] NAKAMURA K, MAKINO O, TACHIBANA A, et al.Quantum chemical study of parasitic reaction in Ⅲ-Ⅴ nitride semiconductor crystal growth[J].Journal of Organometallic Chemistry, 2000, 611(1/2):514-524.
[15] RANDALL CREIGHTON J, WANG G T, COLTRIN M E.Fundamental chemistry and modeling of group-Ⅲ nitride MOVPE[J].Journal of Crystal Growth, 2007, 298:2-7.
[16] ZUO R, ZHANG H, WANG B L, et al.Quantum chemistry study on the adduct reaction paths as functions of temperature in GaN/AlN MOVPE growth[J].ECS Journal of Solid State Science and Technology, 2016, 5(12):P667-P673.
[17] 唐子涵.GaN-MOCVD垂直喷淋式反应室的优化设计[D].南昌:南昌大学,2016.
TANG Z H.Optimal design of vertical showerhead GaN-MOCVD reactor[D].Nanchang:Nanchang University, 2016(in Chinese).
[18] 卢钦,左然,刘鹏,等.MOCVD生长AlN的化学反应-输运过程数值模拟研究[J].人工晶体学报,2014,43(5):1179-1185.
LU Q, ZUO R, LIU P, et al.Numerical simulation study on chemical reaction-transport process of AlN MOCVD growth[J].Journal of Synthetic Crystals, 2014, 43(5):1179-1185(in Chinese).