衬底氮化时间对玻璃衬底上低温沉积GaN薄膜结晶性的影响

Effect of substrate nitriding time on the crystalline characteristics of GaN flim deposited on glass substrate at low temperature

采用电子回旋共振-等离子体增强金属有机物化学气相沉积(ECR-PEMOCVD)方法,在康宁7101型普通玻璃衬底上低温沉积氮化镓(GaN)薄膜。利用反射高能电子衍射(RHEED)、X射线衍射(XRD)、原子力显微镜(AFM)和霍尔测量系统检测样品,研究了衬底氮化时间对GaN薄膜质量的影响。结果表明,氮化时间为5min时,得到的GaN薄膜呈高度c轴择优取向,结晶性较好,薄膜表面是由许多亚微米量级的表面岛按一致的取向规则堆砌而成的,薄膜表面较为平整且呈n型导电;氮化时间增加,薄膜结晶性反而变差。

GaN films have been deposited on corning 7101 glass substrate by electron cyclotron resonance plasma enhanced metal organic chemical vapor deposition （ECR-PEMOCVD） system at low temperature. The effect of substrate nitriding time on the quality of GaN flim is studied using reflection high energy electron diffraction （RHEED）, X-ray diffraction （XRD）, atomic force microscope （AFM） and Hall measurements. The results show that GaN film deposited with substrate nitrided for 5min is of high c-axis preferred orientation and highly Crystallined, its surface is composed of many submicron grains piled in the consistent orientation and the film shows the n-type electrical behavior. The crystallization of GaN film degrades as the substrate nitriding time increased.