Patent ID: 7407859

Claim:
A method of manufacturing a compound semiconductor device comprising the steps of: (a) epitaxially laminating above a substrate a channel layer consisting essentially of GaN, an electron supply layer consisting essentially of n-type AlqGal-qN (0<q (1) and a cap layer consisting essentially of n-type GaN, in this order recited; (b) forming a gate electrode on said cap layer, said gate electrode having a Schottky contact; (c) etching at least part of the cap layer to form recesses on both sides of said gate electrode on source and drain sides, in such a manner that a bottom surfaces of said recesses have a roughness larger than a roughness of a surface of said cap layer under said gate electrode; and (d) forming a source electrode and a drain electrode on the bottom surfaces of said recesses on the source and drain sides.