Patent ID: 6365477
Filing Date: 2002-04-02
Classification: H01L

Abstract:
A method for producing a heterobipolar transistor arranged on a substrate of semiconductor material, including:growing a semiconductor layer sequence for a collector, a base and an emitter on the surface of the substrate; configuring the transistor in a mesa design with the outer surface of the base layer being entirely covered by a protective layer of at least one adjacent emitter layer, thereafter carrying out a first planarizing step by forming an insulating layer on the upper surface of the substrate to the outer limit of the base layer; thereafter partially removing a portion of the at least one adjacent emitter layer to expose the outer surface of the base layer; forming a base contact on the exposed surface of the base layer; carrying out a second planarizing step by forming a second insulating layer on the upper surface of the substrate to at least the outer surface of the emitter layer; and, forming surface contacts for the emitter, base and collector by forming openings in the insulating layers where necessary and then depositing a final coating of the metal.