SUBSTRATE COMPRISING MULTILAYERED GROUP III-NITRIDE SEMICONDUCTOR BUFFER

摘要

A substrate (200) for group III-nitride devices comprises an initial substrate (102) and a buffer structure (204) of a stack of layer pairs (206, 207, 208, 210) located on the substrate. The material of the substrate is different from the materials of the layer pairs. Each layer pair includes a buffer layer of low-temperature-deposited nitride semiconductor material (212, 216, 220) preferably GaN or AlGan and a single-crystal layer of single-crystal GaN (214, 218, 222) grown directly on the buffer layer. At least one of the layer pairs (210) is structured to exhibit in-plane strain that is no more tensile that the in-plane strain in the single-crystal layer of another of the layer pairs on which the at least one of the layers is located.