BIPOLAR TRANSISTOR HAVING A COLLECTOR REGION WITH SELECTIVE DOPING PROFILE AND PROCESS FOR MANUFACTURING THE SAME

摘要

Parts of the emitter (70) and base (76) of a vertical bipolar transistor adjoin a field-isolation region to form a walled-emitter structure. The transistor is furnished with extra doping in the collector (86) and, optionally, in the base (76). The extra collector doping is provided along collector-base junction below the intrinsic base (76A) to create a special collector zone (88) spaced laterally apart from the field-isolation region (64). The presence of the special collector zone (88) causes the intrinsic base (76A) to be thinner, thereby raising the cutoff frequency and overall current gain. The extra base doping is provided in the instrinsic base along the field-isolation region (64) to improve the transistor's breakdown voltage and leakage current characteristics.