Effects of substrate pretreatment and buffer layers on GaN epilayers grown by hydride vapor phase epitaxy

We have studied the effects of substrate nitridation and buffer layers on the structural quality of GaN grown by HVPE. Our work shows that, at certain process conditions, both substrate nitridation and buffer layers can improve the crystalline quality of GaN grown by HVPE. This indicates that the two techniques are transferable to the HVPE growth of high quality GaN.