Abstract Hexagonal V-pits with an inverted pyramid shape appear on the surface of a GaN film after etching by hot H 3 PO 4 . A regular structure that is different from the V-pit morphology is observed in the cathodoluminescence image. The carrier concentration and stress distributions are nonuniform inside the V-pit. Furthermore, no dominant dislocations or defects are observed in the facets or bottom area of the V-pits. An island coalescence process is considered to contribute to the formation of such V-pits, with the coalesced island facets changing from {1 0 1 m} to {1 1 2 m} at a concave state for the different growth velocities.

中文翻译：

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HVPE 生长 GaN 薄膜中特殊 V 凹坑的性质和形成过程研究

摘要 GaN薄膜经热H 3 PO 4 刻蚀后，表面出现倒金字塔形状的六边形V型凹坑。在阴极发光图像中观察到不同于 V 凹坑形态的规则结构。V 坑内的载流子浓度和应力分布不均匀。此外，在 V 坑的小平面或底部区域中没有观察到显性位错或缺陷。岛合并过程被认为有助于形成这种 V 凹坑，对于不同的生长速度，合并的岛面从 {1 0 1 m} 变为 {1 1 2 m} 处于凹状态。