Variable gain transistor structure employing base zones of various thicknesses and resistivities

Claim 1

A BIPOLAR TRANSISTOR COMPRISING A SEMICONDUCTOR BODY HAVING EMITTER, BASE, AND COLLECTOR ZONES OF ALTERNATE CONDUCTIVITY TYPE FORMING AT LEAST TWO P-N JUNCTIONS, SAID EMITTER, BASE, AND COLLECTOR ZONES BEING ARRANGED IN SERIES WITH THE BASE ZONE CONTIGUOUS WITH AND UNDERNEATH THE EMITTER ZONE AND THE COLLECTOR ZONE UNDERNEATH THE BASE ZONE, THE THICKNESS OF THE BASE ZONE BEING DEFINED AS ITS SMALLEST DIMENSION BETWEEN THE JUNCTIONS IN THE SERIES DIRECTION OF THE ZONES, THE PORTION OF SAID BASE ZONE LYING UNDERNEATH THE EMITTER ZONE BEING DIVIDED INTO AT LEAST TWO TRANSVERSE REGIONS OF DIFFERENT THICKNESS WITH EACH OF SAID REGIONS HAVING A UNIFORM THICKNESS AND BEING CONTIGUOUS WITH THE BASE ZONE, CONNECTIONS TO THE EMITTER AND COLLECTOR ZONES, A FIRST BASE CONNECTION TO THE THICKER REGION OF THE BASE PORTION, A SECOND BASE CONNECTION TO THE THINNER REGION OF THE BASE PORTION, MEANS FOR BIASING THE EMITTER ZONE TO INJECT CARRIERS INTO THE BASE ZONE, MEANS FOR BIASING THE COLLECTOR ZONE TO COLLECT CARRIERS FROM THE BASE ZONE, AND MEANS FOR APPLYING A BIAS VOLTAGE BETWEEN THE FIRST AND SECOND BASE CONNECTIONS TO ESTABLISH A TRANSVERSE ELECTRICAL FIELD IN THE BASE PORTION AND SELECTIVELY CONTROL THE INJECTED CARRIER FLOW PRINCIPALLY THROUGH THE THICKER OR THINNER BASE REGIONS.