PROCESS FOR PRODUCING A BIPOLAR VERTICAL TRANSISTOR STRUCTURE

摘要

A method for making a high performance bipolar transistor characterized by self-aligned emitter and base regions and minimized base and emitter contact spacing. The disclosed method comprises forming a recessed oxide-isolated structure having opposite conductivity epitaxial layer and substrate. Multiple layered mass of alternating silicon nitride and silicon dioxide layers are placed over the base region and over the collector reach-through region. Polycrystalline silicon is deposited between the mesas. The mesas are undercut-etched to expose the extrinsic base region which is ion implanted. Then, the mesas are removed to expose the emitter and intrinsic base regions as well as the collector reach-through regions. The latter exposed regions are ion implanted appropriately. Contacts are made directly to the emitter and collector reach-through regions and indirectly via the polysilicon to the base region.