利用金属有机物化学气相沉积技术在具有斜切角度的蓝宝石衬底(0~0.3°)上生长了非故意掺杂GaN薄膜,并采用显微镜、X射线双晶衍射、光荧光及霍尔技术对外延薄膜的表面形貌、晶体质量、光学及电学特性进行了分析。结果表明,采用具有斜切角度的衬底,可以有效改善GaN外延薄膜的表面形貌、降低位错密度、提高GaN的晶体质量及其光电特性,并且存在一个衬底最优斜切角度0.2°,此时外延生长出的GaN薄膜的表面形貌和晶体质量最好。
The undoped GaN films were grown on mis-eut sapphire substrates with different angle (0-0.3°) by MOCVD. Samples were investigated by microscopy, double crystal X-ray diffractometry (DCXRD), photolumineseence (PL), hall technique to character their morphological, crystal properties. The results revealed that the dislocation density of the GaN films decreased by using a suitable angle of mis-cut sapphire substrate. With an angle of 0.2°, the best surface morphological and crystal quality of the GaN films can be obtained.