Method for producing semiconductor integrated circuit device

Claim 1

A method for manufacturing a semiconductor device including at least one MOSFET and at least one bipolar transistor, comprising the steps of: (a) providing a semiconductor body having a main surface, said body including a first semiconductor region of a first conductivity type in which a MOSFET is to be formed, and a second semiconductor region of a second conductivity type opposite to said first conductivity type, in which a bipolar transistor is to be formed, in said main surface; (b) forming a gate electrode of said MOSFET on said first semiconductor region through a gate insulating film; (c) introducing a first impurity of said second conductivity type into a surface of said first semiconductor region at both sides of said gate electrode, and also introducing simultaneously said first impurity into a surface of said second semiconductor region, whereby there are formed a pair of third semiconductor regions serving as part of source and drain regions of said MOSFET in said first semiconductor region and a fourth semiconductor region in said second semiconductor region; (d) introducing a second impurity of a higher concentration that than of said fourth semiconductor region, of said first conductivity type, into said second semiconductor region, whereby there is formed a fifth semiconductor region of said first conductivity type serving as a base region of said fourth semiconductor region, so as to overlap with said fourth semiconductor region; and (e) introducing a third impurity of said second conductivity type having a concentration higher than that of said first impurity into said fifth semiconductor region, whereby there is formed a sixth semiconductor region serving as an emitter region of said bipolar transistor.

Claim 2

A method for manufacturing a semiconductor device including at least one MOSFET and at least one bipolar transistor, comprising the steps of: (a) providing a semiconductor body having a main surface, said body including a first semiconductor region of a first conductivity type in which a MOSFET is to be formed, and a second semiconductor region of a second conductivity type opposite to said first conductivity type, in which a bipolar transistor is to be formed, in said main surface; (b) forming a gate electrode of said MOSFET on said first semiconductor region through a gate insulating film; (c) introducing a first impurity of said second conductivity type into a surface of said first semiconductor region at both sides of said gate electrode, and also introducing simultaneously said first impurity into a surface of said second semiconductor region, whereby there are formed a pair of third semiconductor regions serving as part of source and drain regions of said MOSFET in said first semiconductor region and a fourth semiconductor region in said second semiconductor region; (d) introducing a second impurity of a higher concentration that than of said fourth semiconductor region, of said first conductivity type, into said second semiconductor region, whereby there is formed a fifth semiconductor region of said first conductivity type serving as a base region of said fourth semiconductor region, so as to overlap with said fourth semiconductor region; and (e) introducing a third impurity of said second conductivity type having a concentration higher than that of said first impurity into said fifth semiconductor region, whereby there is formed a sixth semiconductor region serving as an emitter region of said bipolar transistor.