Epitaxial substrate for semiconductor device, semiconductor device, and method of manufacturing epitaxial substrate for semiconductor device

摘要

An epitaxial substrate having preferable two dimensional electron gas characteristic and contact characteristic is provided in the present invention. A channel layer is formed on a base substrate with GaN. A spacer layer is formed on the channel layer with A1N. A barrier layer is formed on the spacer layer with group III nitride having a composition of In x Al y Ga z N (wherein x+y+z=1) and at least including In, Al, and Ga such that the composition of the barrier layer is within the range surrounded with four lines defined in accordance with the composition on a ternary phase diagram with InN, A1N, and GaN as vertexes.