Improvements in a-plane GaN crystal quality by a two-step growth process
Improvements in a-plane GaN crystal quality by a two-step growth process
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DOI：
10.1063/1.2830023
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发表时间：
2008-03-10
影响因子：
4
通讯作者：
Humphreys, C. J.
中科院分区：
文献类型：
--
作者：
Hollander, J. L.;Kappers, M. J.;Humphreys, C. J.
采用金属有机物气相沉积法在r面（1（1）over bar 02）蓝宝石上生长了非极性（11（2）over bar 0）a面GaN薄膜。横向生长是有利的，使用低V：III比率，导致在膜具有光滑的表面，而有坑的膜生长在高V：III比率，表明优先轴上生长。两种膜类型的高分辨率X-射线衍射分析表明，相对于面内取向，Φ的对称欧米茄摇摆曲线的峰宽中的强各向异性。当在降低膜聚结的V：III比之前以高V：III比开始生长时，实现了结晶度的面内各向同性行为与整体降低的ω半峰全宽值。通过初始表面粗糙化的晶体质量的改善同样实现了通过将部分覆盖的氮化硅中间层。(C)2008年美国物理研究所。
Nonpolar (11 (2) over bar0) a-plane GaN films have been grown by metal-organic vapor deposition on r-plane (1 (1) over bar 02) sapphire. Lateral growth is favored using a low V:III ratio resulting in films with a smooth surface, while pitted films are grown at a high V:III ratio indicating preferential on-axis growth. High-resolution x-ray diffraction analysis of both film types showed a strong anisotropy in the peak width of the symmetric omega rocking curve with respect to the in-plane orientation, phi. In-plane isotropic behavior of crystallinity with overall reduced omega full width at half maximum values was achieved when the growth was initiated at a high V:III ratio before reducing the V:III ratio for film coalescence. An improvement of crystal quality through initial surface roughening was equally realized by the incorporation of partial-coverage SiNx interlayers. (C) 2008 American Institute of Physics.