Patent ID: 7906417

Claim:
A method for manufacturing a compound semiconductor device comprising: (A) epitaxially growing layers including a channel layer and a resistance lowering cap layer in the order from a lower layer, above a compound semiconductor substrate by MOCVD; (B) forming source and drain electrodes in ohmic contact with said channel layer; (C) forming a first insulating film on said cap layer, said first insulating film covering said source and drain electrodes; (D) forming an electron beam resist layer on said first insulating film and performing electron beam exposure at different doses, at a high dose for a recess forming opening and at a low dose for an eaves portion removing opening; (E) developing said electron beam resist layer with low solubility developing liquid to form the recess forming opening, and etching said first insulating film; (F) selectively wet-etching said cap layer by using as a mask said electron beam resist layer formed with said recess forming opening and said first insulating film, to form a recess wider than said recess forming opening and leave eaves portions of said first insulating film protruding over said recess; (G) developing said electron beam resist layer with high solubility developing liquid to form the eaves portion removing opening, and etching said exposed first insulating film to extinguish the eaves portions of said first insulating film; (H) forming a second insulating film on an exposed semiconductor surface, said second insulating film covering said first insulating film; (I) forming a resist pattern having a gate electrode opening on said second insulating film; and (J) forming a gate electrode forming metal layer on said resist pattern to form a gate electrode by lift-off.