Patent ID: 8482030

Claim:
An insulated gate bipolar transistor comprising: a buffer layer of a first conductivity type; a first drift layer formed on a first main surface of said buffer layer; a second drift layer of the first conductivity type formed on said first drift layer; a base layer of a second conductivity type formed on said second drift layer; an emitter layer of the first conductivity type selectively formed in a surface of said base layer; a gate electrode buried from a surface of said emitter layer through into said second drift layer with a gate insulating film therebetween; an emitter electrode conducting to said emitter layer; a collector layer of the second conductivity type formed on a second main surface of said buffer layer; and a collector electrode formed on said collector layer, said first drift layer having a structure in which a first layer of the first conductivity type and a second layer of the second conductivity type are repeated in a horizontal direction.