Patent ID: 6043554
Filing Date: 2000-03-28
Classification: H01L

Abstract:
A bipolar transistor comprising:a first semiconductor layer of first conduction type used as a collector;a first insulating film formed on said first semiconductor layer and provided with a base opening in an area where a base layer is formed;an epitaxial layer of second conduction type formed both inside said base opening and on said first insulating film, said epitaxial layer being a base layer inside said base opening and a base output electrode on said first insulating film;an offset insulating film pattern formed on said epitaxial layer in said base opening, away from the edge of said base opening;a graft base layer of second conduction type formed both in said epitaxial layer and on said first semiconductor layer near the edge of said base opening;a second insulating film formed to cover said epitaxial layer and said offset insulating film pattern;an emitter opening formed so that it reaches the surface of said epitaxial layer through both said second insulating film and said offset insulating film pattern;an emitter output electrode of first conduction type formed in said emitter opening so as to be connected to said epitaxial layer; andan emitter layer of first conduction type formed on an upper layer of said epitaxial layer to which said emitter output electrode is connected.