GaN homoepitaxy by metalorganic chemical-vapor deposition on free-standing GaN substrates
GaN homoepitaxy by metalorganic chemical-vapor deposition on free-standing GaN substrates
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DOI：
10.1063/1.1311596
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发表时间：
2000-09
影响因子：
4
通讯作者：
C. Miskys;M. Kelly;O. Ambacher;G. Martínez-Criado;M. Stutzmann
中科院分区：
文献类型：
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作者：
C. Miskys;M. Kelly;O. Ambacher;G. Martínez-Criado;M. Stutzmann
采用金属有机化学气相沉积的方法，在独立的GaN衬底上制备了晶格匹配的GaN层，该衬底采用氢化物气相外延法生长300 μm厚的薄膜，并通过激光诱导升起制备。在GaN的同外延生长之前，独立薄膜的预处理包括对ga表面进行机械抛光和最后的cl基等离子蚀刻。通过高分辨率x射线衍射、原子力显微镜以及拉曼光谱和光致发光光谱的结合，表征了晶格匹配GaN层的结构和光学性质。得到了（0002）、（0004）和（0006）反射的x射线衍射图，其半峰全宽（FWHM）低至20弧秒。位错密度为2×107 cm−2，表面形貌以约200 nm的双层台阶为主。GaN衬底与同外延层之间的晶格失配小于3×10−5，导致FWHM非常窄。
Lattice-matched GaN layers are grown by metalorganic chemical-vapor deposition on free-standing GaN substrates, which were fabricated by laser-induced liftoff of 300-μm-thick films grown by hydride vapor-phase epitaxy. Pretreatment of the free-standing films before the homoepitaxial growth of GaN involved mechanical polishing of the Ga-face surface and a final Cl-based plasma etch. By a combination of high-resolution x-ray diffraction, atomic-force microscopy, as well as Raman and photoluminescence spectroscopy, the structural and optical properties of the lattice-matched GaN layers are characterized. X-ray diffraction patterns of (0002), (0004), and (0006) reflexes with a full width at half maximum (FWHM) of as low as 20 arcsec are obtained. The dislocation density is determined to be 2×107 cm−2 and the surface morphology is dominated by bilayer steps with terraces of about 200 nm. The lattice mismatch between the GaN substrate and the homoepitaxial layer is below 3×10−5, resulting in a very narrow FWHM ...