N-drive, p-common light-emitting devices fabricated on an n-type substrate and method of making same

摘要

A substantially n-type substrate structure having a p-type surface for use in semiconductor devices as a substitute for a p-type semiconductor substrate. The substrate structure comprises a substrate region and a buffer region. The substrate region is a region of n-type compound semiconductor, and includes a degeneratively n-doped portion adjacent its first surface. The buffer region is a region of compound semiconductor doped with a p-type dopant. The buffer region is located on the first surface of the substrate region and includes a surface remote from the substrate region that provides the p-type surface of the substrate structure. The buffer region also includes a degeneratively p-doped portion adjacent the degeneratively n-doped portion of the substrate region. The substrate structure includes a tunnel junction between the degeneratively n-doped portion of the substrate region and the degeneratively p-doped portion of the buffer region. The substrate structure is made by degeneratively doping a substrate region of n-type compound semiconductor material adjacent its first surface with an n-type impurity, and depositing a layer of compound semiconductor material doped with a p-type impurity on the first surface of the substrate region to form a buffer region that includes a surface remote from the substrate region. In the course of depositing the compound semiconductor material to form the buffer region, the compound semiconductor material is degeneratively doped with the p-type impurity at least in a portion adjacent the substrate region to form a tunnel junction between the substrate region and the buffer region.