Method of manufacturing transistors

摘要

A method of manufacturing a semiconductor device is set forth to provide a high-frequency bipolar transistor with very fine emitter-base geometry. The method comprises the steps of forming a base region, forming an insulating layer on the base region, and implanting emitter zones and base contact zones in windows in the insulating layer. Only emitter windows are first formed, then the emitter zones are implanted and a masking layer is provided on the insulating layer and in the emitter windows so that the base contact windows can be etched through apertures in the masking layer. The base contact zones are then implanted to the base contact windows.