Origin of lattice bowing of freestanding GaN substrates grown by hydride vapor phase epitaxy
Origin of lattice bowing of freestanding GaN substrates grown by hydride vapor phase epitaxy
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DOI：
10.1063/1.4940914
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发表时间：
2016-01-28
影响因子：
3.2
通讯作者：
Tadatomo, Kazuyuki
中科院分区：
文献类型：
--
作者：
Yamane, Keisuke;Matsubara, Tohoru;Tadatomo, Kazuyuki
本文描述了一种机制来解释的氢化物气相外延蓝宝石衬底上生长的独立GaN衬底的晶格弯曲。独立式GaN衬底通常呈现凹形。结果表明，上表面的曲率半径和晶格常数与下表面的曲率半径和晶格常数几乎相同。这表明GaN晶格的完全弛豫，即使独立GaN衬底表现出曲率。它示出，除了传统上已知的螺纹位错，位错存在于垂直于生长方向的平面中，这些被称为在/平面位错。在此基础上，定量地证明了与面内位错有关的超半面是导致晶格弯曲的主要原因。(C)2016 AIP Publishing LLC.
This paper describes a mechanism to explain the lattice bowing of freestanding GaN substrates grown by hydride vapor phase epitaxy on sapphire substrates. The freestanding GaN substrates typically exhibit a concave shape. It is revealed that the radius of curvature and lattice constant of the top surface are almost the same as those of the bottom surface. This is indicative of the complete relaxation of the GaN lattice, even though the freestanding GaN substrate exhibited a curvature. It is shown that dislocations are present in a plane normal to the growth direction in addition to conventionally known threading dislocations; these are referred to as in/plane dislocations. Based on these results, it is proven quantitatively that the extra-half planes related to the in-plane dislocations are primarily responsible for the phenomenon of lattice bowing. (C) 2016 AIP Publishing LLC.