There are disclosed herein various implementations of a semiconductor structure and method. The semiconductor structure comprises a substrate, a transition body over the substrate, and a group III-V intermediate body having a bottom surface over the transition body. The semiconductor structure also includes a group III-V device layer over a top surface of the group III-V intermediate body. The group III-V intermediate body has a continuously reduced impurity concentration wherein a higher impurity concentration at the bottom surface is continuously reduced to a lower impurity concentration at the top surface.
STATEMENT OF GOVERNMENT INTEREST
This invention was made with Government support under Contract No. DE-AR0000016 awarded by Advanced Research Projects Agency-Energy (ARPA-E). The Government has certain rights in this invention.