Observation of columnar microstructure in lattice-matched InAlN/GaN grown by plasma assisted molecular beam epitaxy
Observation of columnar microstructure in lattice-matched InAlN/GaN grown by plasma assisted molecular beam epitaxy
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DOI：
10.1063/1.4725482
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发表时间：
2012-06
影响因子：
4
通讯作者：
Soojeong Choi;Feng Wu;R. Shivaraman;E. Young;J. Speck
中科院分区：
文献类型：
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作者：
Soojeong Choi;Feng Wu;R. Shivaraman;E. Young;J. Speck
名义上晶格匹配的InAlN/GaN生长的等离子体辅助分子束外延，并通过X射线衍射，透射电子显微镜和原子探针断层扫描的本征微观结构进行了研究。InAlN为胞状结构，由宽约10 nm的富Al核和宽约1 nm的富In晶界组成。尽管In的横向分布很不均匀，但垂直和横向晶格都不受胞状结构的影响，这可以通过轴上ω−2θ高分辨率X射线衍射扫描中的强厚度条纹、来自轴上（0002）和离轴（101 <$2）ω−2θ高分辨率X射线衍射扫描的相干长度以及对轴上反射的修改后的Williamson-Hall分析来证明。
Nominally lattice matched InAlN/GaN was grown by plasma-assisted molecular beam epitaxy, and the intrinsic microstructure was investigated via x-ray diffraction, transmission electron microscopy, and atom probe tomography. The InAlN showed a cellular structure, which was comprised of ∼10 nm wide Al-rich cores and ∼1 nm In-rich InAlN intercellular boundaries. Despite the strong laterally non-uniform In distribution, both vertical and lateral lattices are unperturbed by the cellular structure, as evidenced by strong thickness fringes in on-axis ω−2θ high resolution x-ray diffraction scans, coherence lengths derived from on-axis (0002) and off-axis (101¯2) ω−2θ high resolution x-ray diffraction scans, and a modified Williamson-Hall analysis for on-axis reflections.