Patent ID: 7005723

Claim:
A method of producing a bipolar transistor, comprising: providing a semiconductor substrate having a substrate surface; forming a base-terminal layer on the substrate surface for providing a base terminal without a sacrificial layer therebetween; forming an emitter window, comprising a wall area, in the base-terminal layer; forming a first spacing layer on the wall area of the emitter window; etching a recess in the semiconductor substrate within a window specified by the first spacing layer; forming a base layer in the recess of the emitter window; forming a second spacing layer on the first spacing layer and on the base layer; structuring the second spacing layer for the purpose of specifying a planar terminal pad on the base layer; forming an emitter layer on the planar terminal pad, wherein a conductive connection between the base layer and the base-terminal layer is produced by diffusing a dopant out of the base-terminal layer into the semiconductor substrate.