Patent ID: 6627972
Filing Date: 2003-09-30
Classification: H01L

Abstract:
A vertical bi-polar transistor with an emitter and a collector, said transistor comprising:a collector terminal; and a base connection zone; at least one inner sub-zone of the base connection zone being designed in the form of a narrow layer combination surrounding the emitter in a ring-like formation, the inner subzone consisting of a highly doped monocrystalline semi-conductor zone and an overlaying highly conductive metal silicide that covers and has contact with the entire highly doped monocrystalline semi-conductor zone with the exception of very narrow peripheral areas that are located under insulating spacers, which serve for peripheral termination of the highly doped monocrystal semi-conductor zone; an outer sub-zone of the base connection zone, consisting of a metal silicide on a highly doped polycrystalline layer of the same material and of the same doping type as a corresponding monocrystalline sub-layer of the inner sub-zone of the base connection zone, and which is separated from the collector or an underlying monocrystalline semiconductor substrate by a thick insulation layer, and which has a low capacity to the collector or the substrate as compared with the inner sub-zone of the base zone; and wherein the inner monocrystalline sub-zone of the base connection zone is adjacent, on three sides thereof, to the collector terminal, and wherein the collector terminal is equally covered and in contact with a highly conductive metal silicide on its entire surface with the exception of narrow peripheral areas covered with a spacer.