Group III nitride semiconductor device

摘要

A group III nitride semiconductor device is disclosed which has a reduced number of threading dislocations adversely affecting characteristics of the group III nitride semiconductor device. A method for manufacturing the group III nitride semiconductor device controls pit formation in a GaN layer formed on a sapphire substrate. First, a low temperature buffer layer is formed on a sapphire substrate_by MOCVD. An undoped GaN layer having a predetermined thickness is then grown on the low temperature buffer layer. Next, a GaN layer containing magnesium as a dopant is formed on the layer at a lower pressure than that of depositing the GaN layer, which results in filling pits generated on the GaN layer to flatten the surface of another GaN layer.