异质外延GaN薄膜中缺陷对表面形貌的影响

Effect of Structural Defects in GaN Epitaxial Layer on Its Surface Morphology

通过对异质外延GaN薄膜中各类结构缺陷进行系统的研究,发现材料内部的各种体、面和线缺陷,包括沉淀物、裂纹、反向边界、局部立方相、小角晶界和位错,都会对表面形貌产生影响,并具有对应的特征形貌。GaN薄膜中缺陷与表面形貌的这种对应关系,可以通过MOCVD生长机理和缺陷间相互作用机制加以解释,同时也提供了一种简单而有效的研究与检测GaN材料内部缺陷的方法。

A systematical observation of several structural defects in GaN layer grown by MOCVD is reported, including precipitate, crack, inversion domain, local cubic phase, low angle grain boundary and dislocations. It is found that each type of these defects will affect the surface morphology of the epilayer, and hence has its own corre- sponding morphology characteristic. This correlation between defects and surface morphology can be interpreted by the growth mechanisms and defect interactions, and also provide an easy and effective way to research and detect defects inside GaN material.