Patent ID: 6894347

Claim:
A semiconductor element, comprising: a first base layer of a first conductivity type; a second base layer of a second conductivity type formed selectively in one surface region of said first base layer; an emitter layer or a source layer of the first conductivity type formed selectively in a surface region of said second base layer; a gate electrode formed on said second base layer positioned between said emitter layer or source layer and said first base layer with a gate insulating film interposed between said gate electrode and said second base layer; a collector layer or a drain layer formed on the other surface region of said first base layer or formed selectively on one surface region of the first base layer; a first main electrode formed on said collector layer or on said drain layer; a second main electrode formed on said emitter layer or source layer and on said second base layer; and a channel region formed in contact with said gate insulating film to permit the carrier to migrate between said emitter layer or source layer and said first base layer, said channel region having an impurity concentration profile along the gate insulating film which is constant substantially between said emitter layer or source layer and said first base layer.