Patent ID: 8587027
Filing Date: 2013-11-19
Classification: H01L

Abstract:
1. A field effect transistor, comprising: a channel layer of a first conductivity type formed above a semiconductor substrate; an upper semiconductor layer comprising at least one semiconductor layer and formed above the channel layer of the first conductivity type; a semiconductor layer of a second conductivity type formed in a recess made in the upper semiconductor, layer or formed above the upper semiconductor layer; a gate electrode placed above and in contact with the semiconductor layer of the second conductivity type; and a gate insulating film including a nitride film formed above and in direct contact with the at least one semiconductor a gate insulating film including a nitride film formed above and in direct contact with the at least one semiconductor layer and an oxide film formed above the nitride film and having a layer and an oxide film formed above the nitride film and having a larger thickness than a thickness of the nitride film, wherein the semiconductor layer of the second conductivity type is buried in an opening formed in the gate insulating film, and wherein a side surface of the oxide film projects towards the semiconductor layer of the second conductivity type as compared with a side surface of the nitride film.