III-NITRIDE SEMICONDUCTOR GROWTH SUBSTRATE, III-NITRIDE SEMICONDUCTOR EPITAXIAL SUBSTRATE, III-NITRIDE SEMICONDUCTOR ELEMENT, III-NITRIDE SEMICONDUCTOR FREESTANDING SUBSTRATE, AND METHOD FOR FABRICATING THESE

摘要

An object of the present invention is to address the problems described herein and to provide a III-nitride semiconductor epitaxial substrate, a III-nitride semiconductor element, and a III-nitride semiconductor freestanding substrate, which have good crystallinity, not only with AlGaN, GaN, or GaInN, the growth temperature of which is at or below 1050 °C, but also with Al x Ga 1-x N, the growth temperature of which is high and which has a high Al composition, as well as a III-nitride semiconductor growth substrate for fabricating these and a method for efficiently fabricating these. The invention is characterized by being equipped with: a crystal growth substrate, at least the surface portion of which substrate includes a III-nitride semiconductor containing Al; and a single metallic layer formed on the surface portion, the single metallic layer being made from Zr or Hf.