Influence Of V/Iii Ratio Of Low Temperature Grown Ain Interlayer On The Growth Of Gan On Si < 111 > Substrate

In this work, the influence of the V/III ratios of the low temperature (LT) AIN interlayer on GaN grown on Si < 111 > substrate have been investigated. It was found that V/III ratio of LT-AIN interlayer is another important growth parameter, which the crystalline quality of GaN was strongly dependent on. By optimizing the V/III ratio of LT-AIN, the high quality crack-free GaN epilayer with lower dislocation density on Si substrate have been obtained. We attribute it to the different LT-AIN surface morphology originated from optimizing the V/III ratio. Different V/III ratios could result in different GaN growth rates in vertical and lateral direction, which could effectively prevent the threading dislocation from penetrating through the LT-AIN interlayer. (C) 2011 The Japan Society of Applied Physics