Semiconductor device production

摘要

A process for forming two bipolar transistors with different properties on a semiconductor substrate (1) involves simultaneously forming a connecting base layer (5), for connecting an extrinsic (graft) base layer of one bipolar transistor and an epitaxially grown intrinsic base layer (12), and at least part of a base layer (6) of the other bipolar transistor. Also claimed is a similar process comprising (a) forming a first insulating layer on the semiconductor substrate (1); (b) opening the layer above regions in which the bipolar transistor base layers are to be formed and simultaneously doping impurities into the regions; and (c) annealing to form the connecting base layer of one bipolar transistor and the base layer of the other bipolar transistor.