论文部分内容阅读
用原子力显微镜和扫描电镜相结合的方法表征了KOH腐蚀后的Si掺杂GaN外延层中的位错腐蚀坑.根据腐蚀坑的不同形状和在表面的特定位置可将其分成三种类型,它们的起源可由一个关于腐蚀机制的模型加以解释.纯螺位错易于沿着由它结束的表面阶梯被腐蚀,形成一个小的Ga极性面以阻止进一步的纵向腐蚀,因而其腐蚀坑是位于两个表面阶梯交结处的截底倒六棱椎.纯刃位错易于沿位错线被腐蚀,因而其腐蚀坑是沿着表面阶梯分布的尖底倒六棱椎.极性在GaN的腐蚀过程中起了重要作用.
The dislocation corrosion pits in KOH-doped Si-doped GaN epitaxial layers were characterized by a combination of atomic force microscopy and scanning electron microscopy, which could be classified into three types according to the different shapes of the corrosion pits and their specific locations on the surface The origin can be explained by a model of the corrosion mechanism, which is apt to be eroded along the surface ladder from which it ends to form a small Ga polar surface to prevent further longitudinal erosion, so that its corrosion pits are located in two The surface of the junction of the ladder at the end of the inverted hexagonal cut.Single-edge dislocation easily along the dislocation line is corroded, and thus its corrosion pits are distributed along the surface of the bottom of the pointed inverted hexagonal vertebrae polarity in the GaN etching process Has played an important role.