Patent ID: 8603871

Claim:
A method for manufacturing a compound semiconductor device comprising: (a) forming a current blocking layer on a top surface of a conductive semiconductor substrate, said current blocking layer being made of high resistance compound semiconductor, and having openings; (b) forming an active layer of compound semiconductor burying said openings and extending on an upper surface of said current blocking layer; (c) forming a gate electrode above said openings and above said active layer; (d) forming a source electrode laterally spaced from said gate electrode and above said active layer; and (e) forming a drain electrode on a bottom surface of said conductive semiconductor substrate; wherein: said conductive semiconductor substrate is made of SiC or GaN; said step (a) includes: (a-1) growing an AlN layer on said conductive semiconductor substrate; and (a-2) patterning said AlN layer to form said openings exposing said conductive semiconductor substrate, and said step (b) includes: (b-1) growing a doped GaN layer in an area including said openings; and (b-2) growing a non-doped GaN layer on said doped GaN layer.