摘要
利用LP-MOCVD技术在Si(111)衬底上,用不同温度生长AlN缓冲层,再在缓冲层上外延GaN薄膜.采用高分辨率双晶X射线衍射(DCXRD)技术和扫描电子显微镜(SEM)分析这些样品,比较缓冲层生长温度对缓冲层和外延层的影响,并提出利用动力学模型解释这种温度的影响.进一步解释了GaN外延层表面形貌中“凹坑”的形成及“凹坑”与缓冲层生长温度的关系.结果表明,温度的高低通过影响缓冲层初始成核密度和成核尺寸来影响外延层表面形貌.
Hexagonal GaN layers are grown on Si（111） substrates using an AlN buffer layer by a vertical LP-MOCVD reactor. DCXRD and SEM are used to characterize the GaN films. The dependence of GaN morphology on the growth temperature of the AlN buffer layer is analyzed. Furthermore,a kinetics model is used to explain the “cave” formation mechanism. It is suggested that growth temperature of the AlN buffer layer influences GaN morphology by forming different AlN seed size and density on the Si（ 111 ） substrate during the initial growth of the buffer layer.
基金
广东省关键领域重点突破基金资助项目(批准号:2B2003A107)~~
