Method for producing group iii nitride compound semiconductor and group iii nitride compound semiconductor device

Abstract

By using a mask , a first Group III nitride compound semiconductor layer is etched, to thereby form an island-like structure such as a dot-like, striped-shaped, or grid-like structure, so as to provide a trench/post. Thus, without removing the mask formed on a top surface of the upper layer of the post, a second Group III nitride compound layer can be epitaxially grown, vertically and laterally, with a sidewall/sidewalls of the trench serving as a nucleus, to thereby bury the trench and also grow the layer in the vertical direction. The second Group III nitride compound layer does not grow epitaxially on the mask . In this case, propagation of threading dislocations contained in the first Group III nitride compound semiconductor layer can be prevented in the upper portion of the second Group III nitride compound semiconductor that is formed through lateral epitaxial growth and a region having less threading dislocations can be formed in the buried portion of the trench.