Semiconductor device

摘要

A semiconductor device of the present invention has an insulating gate type field effect transistor portion having an n-type emitter region ( 3 ) and an n^- silicon substrate ( 1 ), which are opposed to each other sandwiching a p-type body region ( 2 ), as well as a gate electrode ( 5 a) which is opposed to p-type body region ( 2 ) sandwiching a gate insulating film ( 4 a), and also has a stabilizing plate ( 5 b). This stabilizing plate ( 5 b) is made of a conductor or a semiconductor, is opposed to n^- silicon substrate ( 1 ) sandwiching an insulating film ( 4, 4 b) for a plate, and forms together with n^- silicon substrate ( 1 ), a capacitor. This stabilizing plate capacitor formed between stabilizing plate ( 5 b) and n^- silicon substrate ( 1 ) has a capacitance greater than that of the gate-drain capacitor formed between gate electrode ( 5 a) and n^- silicon substrate ( 1 ).