Initial stages of GaN/GaAs (100) growth by metalorganic chemical vapor deposition
Initial stages of GaN/GaAs (100) growth by metalorganic chemical vapor deposition
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金属有机化学气相沉积 GaN/GaAs (100) 生长的初始阶段
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
R. Wu
中科院分区：
文献类型：
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作者：
Dapeng Xu;Hui Yang;J. B. Li;S. Li;Y. Wang;D. G. Zhao;R. Wu
研究了金属有机化学气相沉积(MOCVD)法在GaN(100)衬底上生长GaN缓冲层。用原子力显微镜(AFM)和反射高能电子衍射仪(RHEED)研究了生长温度、生长速率、退火效应和生长时间对成核的影响。必须使用两步生长序列来独立地优化和控制形核和随后的生长。岛的大小和分布以及缓冲层的厚度对GaN层的质量起着至关重要的作用。根据实验结果，给出了六方相GaN在立方相GaN层中形成的模型。采用优化的缓冲层，在室温下观察到立方GaN的强近带发射，其半高半宽(FWHM)值最小为5.6 nm。背景载流子浓度估计在1013∼1014 cm−3的范围内。
We have investigated the growth of GaN buffers by metalorganic chemical vapor deposition (MOCVD) on GaAs (100) substrates. Atomic force microscope (AFM) and reflection high-energy electron diffraction (RHEED) were employed to study the dependence of the nucleation on the growth temperature, growth rate, annealing effect, and growth time. A two-step growth sequence must be used to optimize and control the nucleation and the subsequent growth independently. The size and distribution of islands and the thickness of buffer layers have a crucial role on the quality of GaN layers. Based on the experimental results, a model was given to interpret the formation of hexagonal-phase GaN in the cubic-phase GaN layers. Using an optimum buffer layer, the strong near-band emission of cubic GaN with full-width at half maximum (FWHM) value as small as 5.6 nm was observed at room temperature. The background carrier concentration was estimated to be in the range of 1013 ∼ 1014 cm−3.