Method of manufacturing ic comprising a bipolar transistor and ic

Abstract

Disclosed is a method of manufacturing an integrated circuit comprising a bipolar transistor, the method comprising providing a substrate () comprising a pair of first isolation regions () separated from each other by an active region () comprising a collector impurity said bipolar transistor; forming a base layer stack (') over said substrate; forming a further stack of a migration layer () having a first migration temperature and an etch stop layer () over said base layer stack (); forming a base contact layer () having a second migration temperature over the further stack, the second migration temperature being higher than the first migration temperature; etching an emitter window () in the base contact layer over the active region, said etching step terminating at the etch stop layer; at least partially removing the etch stop layer, thereby forming cavities () extending from the emitter window in between the base contact layer and the redistribution layer; and exposing the resultant structure to the first migration temperature in a hydrogen atmosphere, thereby filling the cavities with the migration layer material. An IC comprising such a bipolar transistor is also disclosed.