Patent ID: 8569800
Filing Date: 2013-10-29
Classification: H01L

Abstract:
1. A field effect transistor made of a nitride compound semiconductor, the field effect transistor comprising: a substrate; a buffer layer that is formed on the substrate; a high resistance layer or a foundation layer that is formed on the buffer layer; a carrier concentration controlling layer containing carbon that is formed on the high resistance layer or the foundation layer; a carrier traveling layer that is formed on the carrier concentration controlling layer; a carrier supplying layer that is formed on the carrier traveling layer; a recess that extends from the carrier supplying layer into the high resistance layer or the foundation layer; a source electrode and a drain electrode that are formed on the carrier supplying layer with the recess intervening therebetween; a gate insulating film that is formed on the carrier supplying layer so as to cover the recess; and a gate electrode that is formed on the gate insulating film in the recess, wherein the carrier traveling layer includes a two-dimensional electron gas generated therein due to a difference of bandgap energy between the carrier traveling layer and the carrier supplying layer.