利用MOCVD技术在斜切角度为0.3°的c面蓝宝石衬底上生长了非故意掺杂GaN薄膜,并采用透射电子显微镜对材料的质量和材料内部缺陷进行了分析.研究发现斜切蓝宝石衬底上外延的GaN材料中,位错在距离衬底0.8μm附近大量湮灭,同时位错扎堆出现.基于上述现象,提出了斜切衬底上GaN材料中位错的湮灭机制,解释了斜切衬底能够提高GaN晶体质量的原因. An unintentionally doped GaN film was grown on a c-plane sapphire substrate with a bevel angle of 0.3 ° by MOCVD technique and the quality of the material and the material internal defects were analyzed by transmission electron microscopy. It was found that the chamfered sapphire substrate In the epitaxial GaN material, the dislocations annihilate a great deal at 0.8μm away from the substrate, and the dislocations get together.Furthermore, the annihilation mechanism of dislocation in the GaN material on a beveled substrate is proposed, Bottom can improve the quality of GaN crystal.