Semiconductor device having a vertical channel of carriers

A semiconductor device, comprising:

• an emitter layer of a semiconductor material having first and second opposing major surfaces, said second major surface comprising a plurality of stepped surfaces, said emitter layer releasing carriers,
• a base layer having first and second opposing major surfaces and provided on said emitter layer such that the first major surface of said base layer opposes the second major surface of said emitter layer, the first major surface of said base layer comprising a plurality of stepped surfaces corresponding to the stepped surfaces of the second major surface of said emitter layer, said base layer comprising a plurality of channels and a plurality of control regions, each of said channels passing the carriers released by said emitter layer therethrough and each of said control regions controlling the passage of the carriers through said channels in response to a base voltage applied thereto, said plurality of channels and said plurality of control regions being disposed alternately in each stepped surface of the first major surface of said base layer, to extend parallel with each other in an elongated direction of the stepped surface of the first major surface of said base layer such that at least one channel and at least one control region are formed adjacent with each other in correspondence to each stepped surface of the first major surface of said base layer;
• a collector layer of a semiconductor material having first and second opposing major surfaces and provided on said base layer such that the first major surface of said collector layer faces the second major surface of said base layer for collecting the carriers that have passed through said channels;
• emitter electrode means, provided in electrical connection to said emitter layer for causing said emitter layer to release the carriers when said emitter electrode means is supplied with an emitter current;
• base electrode means provided in electrical connection to said control regions for applying the base voltage thereto;
• and
• collector electrode means provided in electrical connection to said collector layer for producing a collector current in response to the carriers collected by said collector layer.