VERFAHREN ZUM HERSTELLEN VON SELBSTJUSTIERTEN BIPOLAR-TRANSISTORSTRUKSTUREN MIT REDUZIERTEM BASISBAHNWIDERSTAND.

摘要

A process is claimed for prodn. of bipolar transistor structures with self-adjusting emitter-base regions, in which both the emitter and the base regions are produced in the silicon semiconductor substrate by diffusion from structures which consist of doped polysilicon layers deposited directly on the substrate and which form the subsequent connections. SiO2 layers are used as masking and insulation layers to produce first the base region and then the central emitter region so that symmetrical active and inactive base zones are formed below the emitter region. Dry etching processes are used to produce vertical etch profiles during structuring of the SiO2 and polysilicon layers. The novelty is that, after prodn. of the polysilicon layer structure forming the emitter connection, the polysilicon layer structure forming the base connection is exposed by etching using the emitter layer structure as mask and that, after prodn. of flank insulation layers on both layer structures, the exposed silicon surface is selectively provided with a metallic conductive layer. Also claimed is prodn. of bipolar transistors with buried collector regions and deep-lying collector connections.