Using density functional calculations, we clarify the oxygen incorporation mechanism in vicinal m-GaN growth by metal-organic vapor-phase epitaxy. We first identify reconstructed structures of 5° off m-GaN toward the ±c directions. Next, we explore preferable sites for oxygen substitution near step edges. We find that oxygen prefers the lower nitrogen site of the step edge on the +c 5° off m-GaN substrate compared with that on the –c 5° off m-GaN substrate. This tendency agrees with recent experimental findings that the oxygen concentration in −c 5° off m-GaN epilayers is lower than that in +c 5° off m-GaN epilayers.

中文翻译：

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MOVPE对邻位m(10−10)-GaN生长氧稳定性的计算研究

使用密度泛函计算，我们阐明了金属有机气相外延在邻位 m-GaN 生长中的氧掺入机制。我们首先确定了朝向±c 方向偏离m-GaN 5° 的重构结构。接下来，我们探索台阶边缘附近氧取代的优选位点。我们发现，与 -c 5° off m-GaN 衬底上的相比，氧更喜欢在 +c 5° off m-GaN 衬底上的台阶边缘的较低氮位点。这种趋势与最近的实验结果一致，即 -c 5° off m-GaN 外延层中的氧浓度低于 +c 5° off m-GaN 外延层中的氧浓度。