Method of manufacturing a semiconductor device

Claim 1

A method of manufacturing a semiconductor device having a bipolar transistor and a field effect transistor formed on the same semiconductor substrate, comprising the steps of: forming sequentially a gate insulating film, a first conductor film, and a first film only in a region to form said field effect transistor; forming an external base electrode having a second film formed thereon in a region to form said bipolar transistor; forming an external base region and an intrinsic base region in the region to form said bipolar transistor; forming a first sidewall spacer on a sidewall of said external base electrode in connection with said second film, using said first film as an etching-stopper which prevents said first conductor film from being etched; removing said first film on said first conductor film completely; forming a second conductor film on said semiconductor substrate in contact with said intrinsic base region and said first conductor film; patterning said second conductor film together with said first conductor film to form an emitter electrode in the region to form said bipolar transistor and a gate electrode in the region to form said field effect transistor; forming a third film on the entire surface of said semiconductor substrate so as to cover said gate electrode; etching selectively said third film to form a second sidewall spacer on a sidewall of said gate electrode; forming a protective insulating film on said semiconductor substrate so as to cover said gate electrode, said external base electrode, and said emitter electrode; forming a contact hole for electrical connection to said bipolar transistor and said field effect transistor in said protective insulating film; and forming an electrode interconnection electrically connected to said field effect transistor and said bipolar transistor through said contact hole.

Claim 2

A method of manufacturing a semiconductor device having a bipolar transistor and a field effect transistor formed on the same semiconductor substrate, comprising the steps of: forming sequentially a gate insulating film, a first conductor film, and a first film only in a region to form said field effect transistor; forming an external base electrode having a second film formed thereon in a region to form said bipolar transistor; forming an external base region and an intrinsic base region in the region to form said bipolar transistor; forming a first sidewall spacer on a sidewall of said external base electrode in connection with said second film, using said first film as an etching-stopper which prevents said first conductor film from being etched; removing said first film on said first conductor film completely; forming a second conductor film on said semiconductor substrate in contact with said intrinsic base region and said first conductor film; patterning said second conductor film together with said first conductor film to form an emitter electrode in the region to form said bipolar transistor and a gate electrode in the region to form said field effect transistor; forming a third film on the entire surface of said semiconductor substrate so as to cover said gate electrode; etching selectively said third film to form a second sidewall spacer on a sidewall of said gate electrode; forming a protective insulating film on said semiconductor substrate so as to cover said gate electrode, said external base electrode, and said emitter electrode; forming a contact hole for electrical connection to said bipolar transistor and said field effect transistor in said protective insulating film; and forming an electrode interconnection electrically connected to said field effect transistor and said bipolar transistor through said contact hole.