Microstructure and strain analysis of GaN epitaxial films using in-plane grazing incidence x-ray diffraction
Microstructure and strain analysis of GaN epitaxial films using in-plane grazing incidence x-ray diffraction
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DOI：
10.1088/1674-1056/19/7/076804
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发表时间：
2010-07
影响因子：
1.7
通讯作者：
Guoxi Xi;Wang Yu-Tian;Zhao De-gang;Jiang De-sheng;Zhu Jian-Jun;Liu Zong-shun;Wang Hui;Zhan Shu-ming;Qiu Yong-Xin;Xu Ke;Yang Hui
中科院分区：
文献类型：
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作者：
Guoxi Xi;Wang Yu-Tian;Zhao De-gang;Jiang De-sheng;Zhu Jian-Jun;Liu Zong-shun;Wang Hui;Zhan Shu-ming;Qiu Yong-Xin;Xu Ke;Yang Hui
本文利用掠入射X射线衍射技术研究了用金属有机化学气相沉积法在蓝宝石衬底上生长的（001）取向GaN薄膜的主要结构参数，如晶体质量和应变状态。的结果进行了分析和比较与互补的平面外的X射线衍射技术。通过直接掠入射测量GaN镶嵌结构的（100）面反射，确定了镶嵌结构的扭曲度，与外推法所得结果吻合较好。还提出了直接确定GaN层面内晶格参数的方法。结合双轴应变模型，导出了GaN薄膜完全弛豫时的晶格参数。当GaN外延层进入二维生长阶段时，残余压应力随着层厚的增加而增加，最大值为-0.89GPa。
This paper investigates the major structural parameters, such as crystal quality and strain state of (001)-oriented GaN thin films grown on sapphire substrates by metalorganic chemical vapour deposition, using an in-plane grazing incidence x-ray diffraction technique. The results are analysed and compared with a complementary out-of-plane x-ray diffraction technique. The twist of the GaN mosaic structure is determined through the direct grazing incidence measurement of (100) reflection which agrees well with the result obtained by extrapolation method. The method for directly determining the in-plane lattice parameters of the GaN layers is also presented. Combined with the biaxial strain model, it derives the lattice parameters corresponding to fully relaxed GaN films. The GaN epilayers show an increasing residual compressive stress with increasing layer thickness when the two dimensional growth stage is established, reaching to a maximum level of -0.89 GPa.