Fundamental kinetics determining growth rate profiles of InP and GaAs in MOCVD with horizontal reactor
Fundamental kinetics determining growth rate profiles of InP and GaAs in MOCVD with horizontal reactor
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DOI：
10.1016/j.jcrysgro.2003.11.024
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发表时间：
2004-01-19
影响因子：
1.8
通讯作者：
Shimogaki, Y
中科院分区：
文献类型：
--
作者：
Im, IT;Oh, HJ;Shimogaki, Y
用数值方法系统地分析了与InP和GaAs薄膜生长有关的基本动力学。研究了气相反应速率常数、表面反应速率常数和质量扩散系数对薄膜生长速率的影响。利用基本反应模型，定量和定性地揭示了决定水平MOCVD反应器中典型生长速率分布的限速步骤。在20 cm以上观测到的轴向生长速度剖面分为两个区域：上游区域生长速度单调增加，而下游区域生长速度单调下降。上游区域的增加是由于在垂直方向上远离基座的进气口的III族前体的气相传质所致。质量扩散系数的温度依赖性和热扩散对增加的斜率都有很大的影响。下游区域的减少反映了V族中间体的气相浓度的衰减，其速度受到中间体向基材的气相扩散的限制。利用这一点，我们可以通过观察水平MOCVD反应器中生长速率的衰减来测量III族中间体的质量扩散系数的值。(C)2003爱思唯尔B.V.保留所有权利。
Fundamental kinetics related to the film growth of InP and GaAs are systematically analyzed using numerical methods. Effects of the gas-phase reaction rate constant, the surface reaction rate constant and the mass diffusivity on a film growth rate are investigated. The rate-limiting step determining a typical profile of the growth rate in a horizontal MOCVD reactor is revealed both quantitatively and qualitatively using basic reaction models. The axial growth rate profile observed over 20 cm is divided into two regions: the upstream region where the growth rate increased monotonically and the downstream region where the rate decreased monotonically. The increase in the upstream region was caused by the gas-phase mass transport of the group III precursors from the inlet which was apart from the susceptor in the vertical direction. Both the temperature dependence of the mass diffusivity and the thermal diffusion have strong effect on the slope of the increase. The decrease in the downstream region reflects the decay of the gas-phase concentration of group V intermediates, the rate of which was limited by the gas-phase diffusion of the intermediate to the substrate. Using this, we can measure the value of the mass diffusivity of a group III intermediate by observing the decay in the growth rate in a horizontal MOCVD reactor. (C) 2003 Elsevier B.V. All rights reserved.