NITRIDE SEMICONDUCTOR ELEMENT

摘要

A field effect transistor (1) is provided with: a first insulating film (11) that is formed on the surface of a nitride semiconductor and has an opening (11a); a second insulating film (12) that is formed on the surface of the first insulating film (11) in regions other than the region of the opening (11a) and the region within a certain distance from the edge of the opening (11a); a third insulating film (13) that is formed on the surfaces of the first insulating film (11) and the second insulating film (12); a gate electrode (6) that is formed on the surface of the third insulating film (13); and a field plate part (6a) that protrudes from the gate electrode (6) toward the drain electrode. The two-dimensional electron gas concentration is set to 6.5 × 1012 /cm2 or less, and the length (L) from the edge of the opening (11a) to the end of the field plate part (6a) that protrudes from the gate electrode (6) toward the drain electrode is set to 1.8-2.2μm (inclusive).