Patent ID: 8609474

Claim:
A method for manufacturing a semiconductor device, comprising: forming a source electrode and a drain electrode on a substrate; forming an insulating film by depositing silicon oxide or silicon nitride on the substrate with the source electrode and the drain electrode; forming a field plate electrode on the insulating film; and forming a gate electrode in contact with the field electrode, wherein the formation of the gate electrode includes: applying a third photoresist film of a single layer on the insulating film with the field plate electrode; developing the third photoresist film so as to expose a part of each of the insulating film and the field plate electrode and etching the insulating film using the developed third photoresist film as a mask; forming an outer profile of a first support part by removing an unetched portion of the third photoresist film; applying a first photoresist film of the triple layer onto the insulating film where the outer profile of the first support part is formed; forming outer profiles of a second support part and a head part connected with the first support part by removing a part of the first photoresist film; and vacuum-depositing a gate electrode metal into a void formed by the outer profiles of the first support part, the second support part, and the head part using electron beams and removing an unremoved portion of the first photoresist film, wherein the width W 3 of the second support part is larger than the width W 2 of the first support part.