Mechanisms of bending of threading dislocations in MOVPE-grown GaN on (0001) sapphire
Mechanisms of bending of threading dislocations in MOVPE-grown GaN on (0001) sapphire
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(0001) 蓝宝石上 MOVPE 生长的 GaN 中穿透位错的弯曲机制
DOI：
10.1002/pssc.200565369
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Datta R
中科院分区：
文献类型：
--
作者：
Datta R
在本文中，我们描述了与GaN中线状位错(TD)弯曲到90°有关的可能机制。在蓝宝石衬底上使用SiNx掩蔽的原位ELOG和在GaN伪衬底上原位沉积SiNx中间层(IL)被用来降低GaN中的TD密度。为了减少TDS在上生长层中的数量，TDS弯曲90°是必不可少的。TDS的弯曲是由生长模式的改变所促进的，即主要从2D到3D，然后是3D到2D。试探性地提出了一种新的机制，可以解释所有类型的TDS的弯曲(边缘、螺杆和混合)。这种新的机制是基于当TDS在那里终止时，首先在3D岛侧面形成台阶，然后，根据随后生长模式(3D到2D)的变化和原子台阶运动的方向，TDS将弯曲。(2006 Wiley-VCH Verlag GmbH&Co.KGaA，Weinheim)
In this article, we describe possible mechanisms associated with the bending of threading dislocations (TDs) through 90° in GaN. In‐situ ELOG using SiNxmasking on a sapphire substrate and in‐situ SiNxinterlayer (IL) deposition on a GaN pseudo‐substrate have been used to reduce the TD density in GaN. The bending of TDs through 90° is essential in order to reduce their numbers in the upper growing layer. The bending of TDs is facilitated by a change in growth mode, i.e. predominantly 2D to 3D and then 3D to 2D. A new mechanism is tentatively proposed which can explain the bending of all types of TDs (edge, screw, and mixed). This new mechanism is based on first, step formation at 3D island side facets when TDs terminate there, following which, depending on the subsequent change in growth mode (3D to 2D) and the direction of the atomic ledge movement, the TDs will bend over. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)