| 摘要 |
PURPOSE:To enhance both turning off capacity and reverse dielectric strength and to reduce the manufacturing cost of a semiconductor device by partly increasing the htickness of an N-type base layer at a position corresponding to an N-type emitter of a GTO, and partly reducing the thickness of a P-type emitter layer at the same position. CONSTITUTION:A P-type emitter 1 is partly used as a first semiconductor substrate, and a residue including other layer is separately formed on both substrates as a second semiconductor substrate, and both the substrates are then bonded and integrated. The thickness of a N-type base 2 at a position directly under the center of the N-type emitter is partly increased, while the thickness of the emitter 1 at the same position is decreased. Accordingly, the base 2 has a projection 2a overhung to the emitter 1 side at a bonding surface to the emitter 1, while the emitter 1 has a recess coincident to the projection 2a on the bonding surface. Since the projection 2a has a high resistance different from an N-type high density layer 5 of GTO, its dielectric strength might not be decreased, and a current concentration to an N-type emitter 4 can be prevented at turning off time. |
