Group III nitride semiconductor growth substrate, III-nitride semiconductor epitaxial substrate, III-nitride semiconductor device and a III nitride semiconductor free-standing substrate, as well as methods for their preparation

摘要

PROBLEM TO BE SOLVED: To provide an epitaxial substrate for group-III nitride semiconductors, a group-III nitride semiconductor element, and a stand-alone substrate for group-III nitride semiconductors, which produce good crystallinity not only for AlGaN, GaN, and GaInN compositions having growth temperatures at or below 1,050°C but also Al_xGa_1-xN compositions for high-Al having high growth temperatures; a substrate for growing group-III nitride semiconductors for fabricating the same, and to provide a method of efficient fabrication thereof.;SOLUTION: At least a surface region 2 includes a crystal growth substrate 3 made of an aluminum-containing group-III nitride semiconductor, a single metal layer 4 formed on the surface region 2 and made of crystallized Zr or Hf, and an initial growth layer 5 formed on the single metal layer 4 and formed by at least one buffer layer made of Al_xGa_1-xN (0≤x≤1).;COPYRIGHT: (C)2011,JPO&INPIT