Method of manufacturing a semiconductor device

摘要

A semiconductor device is manufactured by a process comprising the steps of forming a cover film on a surface of a semiconductor substrate such that the cover film exposes a portion of the surface, covers a remaining portion thereof and has an edge along a boundary between the exposed portion and the covered portion, forming a first conductor film in a range from the cover film formed in the cover film forming step through the edge to the exposed surface portion of the semiconductor substrate, removing the first conductor film formed in the first conductor film forming step other than a portion formed along the edge such that the first conductor film is left along the edge, forming an insulating film on the opposite sides of the first conductor film left along the edge in the removing step such that a top edge of the left first conductor film is exposed, and forming a second conductor film on the surface of the insulating film formed in the insulating film forming step along the exposed top edge of the first conductor film. In this method, the gate electrode or the base electrode is formed by a side wall process. It is thus possible to reduce the electrode length/width and improve the response of the element.