Patent ID: 7491984
Filing Date: 2009-02-17
Classification: H01L

Abstract:
1. A Group III nitride compound semiconductor comprising: a substrate; an underlying layer comprising at least one layer of a Group III nitride compound semiconductor, an uppermost layer of said underlying layer being a first Group III nitride compound semiconductor layer, said underlying layer being formed into an island structure including a trench and mesa structure, wherein an area of a horizontal cross section of said mesa is reduced to substantially zero with respect to an increase in a distance between said cross section and said substrate; a mask formed on and covering said first Group III nitride compound semiconductor layer except for a top portion thereof, said mask exposing the top portion of said first Group III nitride compound semiconductor layer; and a second Group III nitride compound semiconductor layer on said mask, being epitaxially grown vertically and laterally from said top portion of said first Group III nitride compound semiconductor layer, said upper surface of said second Group III nitride compound semiconductor being parallel to a surface of said substrate.