Nanoporous gan on p-type gan: a mg out-diffusion compensation layer for heavily mg-doped p-type gan

Abstract

Improved fabrication is provided for devices in the GaN material system that require an embedded p-type layer. The effect of Mg diffusion from the p-type layer is compensated for using an GaN interlayer that is etched to be nanoporous at its top surface. In addition to serving as a diffusion barrier, the GaN interlayer preferably has C and O impurities from the etch that tend to compensate unwanted Mg doping in layers above the GaN interlayer. Importantly, the entire structure can be grown at high temperatures, which desirably avoids low temperature growth steps that tend to reduce material quality.