Influence of AlN buffer layer thickness on the properties of GaN epilayer on Si(111) by MOCVD

The effect of thickness of the high-temperature (HT) AlN buffer layer on the properties of GaN grown on Si(111) has been investigated. Optical microscopy (OM), atomic force microscopy (AFM) and X-ray diffraction (XRD) are employed to characterize these samples grown by metal-organic chemical vapor deposition (MOCVD). The results demonstrate that the morphology and crystalline properties of the GaN epilayer strongly depend on the thickness of HT AlN buffer layer, and the optimized thickness of the HT AlN buffer layer is about 110 nm. Together with the low-temperature (LT) AlN interlayer, high-quality GaN epilayer with low crack density can be obtained. (C) 2008 Elsevier Ltd. All rights reserved.

Key Innovation Program of Chinese Academy of Sciences KGCX2-SW-107-1 National Natural Science Foundation of China 60606002 Special Funds for Major State Basic Research 2002CB311903 2006CB604905 513270605This work has been supported by Key Innovation Program of Chinese Academy of Sciences (No. KGCX2-SW-107-1), National Natural Science Foundation of China (No. 60606002); Special Funds for Major State Basic Research Projects (No. 2002CB311903, 2006CB604905 and 513270605).