Patent ID: 6396085
Filing Date: 2002-05-28
Classification: H01L

Abstract:
A field effect transistor having a vertical structure including a source electrode formed on the top of a semiconductor multilayer film of GaN type and a drain electrode formed on the bottom of said semiconductor multilayer film,said semiconductor multilayer film of GaN type including first through fifth semiconductor layers, wherein: said first semiconductor layer is composed of a GaN-type semiconductor having a low impurity concentration, and constitutes a current path between said source electrode and drain electrode, said first semiconductor layer being provided with a groove portion; said second semiconductor is a high-resistance semiconductor layer composed of an undoped GaN-type semiconductor, and is arranged in said groove portion; said third semiconductor layer is composed a GaN-type semiconductor having conductivity reverse to that of said first semiconductor layer, and is arranged in said groove portion via said second semiconductor layer; said fourth semiconductor layer is composed of a GaN-type semiconductor having conductivity identical to that of said first semiconductor layer, and is buried in said third semiconductor layer to constitute a source region; a source electrode is arranged on the top surface of said source region in said fourth semiconductor layer, and a gate electrode is arranged so as to be insulated from said source electrode; and said fifth semiconductor layer is composed of a GaN-type semiconductor having conductivity identical to that of said first semiconductor layer, and is formed to extend from the top of said first semiconductor layer beneath said gate electrode to said fourth semiconductor layer to constitute a channel layer.