A GaN bulk crystal with improved structural quality grown by the ammonothermal method
A GaN bulk crystal with improved structural quality grown by the ammonothermal method
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DOI：
10.1038/nmat1955
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发表时间：
2007-08-01
期刊：
影响因子：
41.2
通讯作者：
Nakamura, Shuji
中科院分区：
文献类型：
--
作者：
Hashimoto, Tadao;Wu, Feng;Nakamura, Shuji
基于氮化镓和其他氮化半导体的高性能光电器件的实现需要高质量衬底的存在。非极性或半极性衬底最近被证明可以提供优于传统c平面衬底的光学器件（1-4）。体GaN生长使GaN衬底沿各种有利的晶体取向切片。氨热生长是一种极具吸引力的氮化镓生长方法，因为它具有低成本生长氮化镓锭的潜力。本文报道了用氨热法生长的氮化镓结构质量的改善。通过平面透射电镜观察估计，Ga面和N面的螺纹位错密度分别小于1 × 10(6) cm和1 × 10(7) cm。在Ga面界面处未观察到位错生成，而在N面界面处产生了少量缺陷。结构质量的提高，加上之前关于生长速度(5)和可扩展性(6)的报道，证明了氨热生长GaN的商业可行性。
The realization of high-performance optoelectronic devices, based on GaN and other nitride semiconductors, requires the existence of a high-quality substrate. Non-polar or semipolar substrates have recently been proven to provide superior optical devices to those on conventional c-plane substrates(1-4). Bulk GaN growth enables GaN substrates sliced along various favourable crystal orientations. Ammonothermal growth is an attractive method for bulk GaN growth owing to its potential to grow GaN ingots at low cost. Here we report on improvement in the structural quality of GaN grown by the ammonothermal method. The threading dislocation densities estimated by plan-view transmission electron microscopy observations were less than 1 x 10(6) cm(-2) for the Ga face and 1 x 10(7) cm(-2) for the N face. No dislocation generation at the interface was observed on the Ga face, although a few defects were generated at the interface on the N face. The improvement in the structural quality, together with the previous report on growth rate(5) and scalability(6), demonstrates the commercial feasibility of the ammonothermal GaN growth.