Patent ID: 7038273

Claim:
A semiconductor device including a trench gate IGBT, comprising: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type which is formed on one surface of said first semiconductor layer; a base layer of the first conductivity type which is formed in a surface portion of the second semiconductor layer; emitter layers of the second conductivity type which are selectively formed in a surface portion of said base layer; a plurality of trenches which extend through said emitter layers and said base layer and are formed to a predetermined depth in the second semiconductor layer; gate electrodes which are formed on gate insulating films in the trenches; an emitter electrode which is formed on said emitter layers and said base layer; a collector electrode which is formed on the other surface of said first semiconductor layer; an auxiliary base layer of the first conductivity type which is formed in an arbitrary region between two adjacent trenches and is insulated from said emitter electrode; and a carrier discharge electrode which contacts a surface of said auxiliary base layer of the first conductivity type; further comprising a MISFET including a channel region of the first conductivity type; wherein a source of said MISFET is connected to said carrier discharge electrode of the trench gate IGBT, and a drain of said MISFET is connected to said emitter electrode of the trench gate IGBT; wherein said MISFET is mounted in the same package as a package of the trench gate IGBT; wherein said MISFET is formed on a third semiconductor layer which is formed on said second semiconductor layer and insulated from said second semiconductor layer.