Method for manufacturing a bipolar junction transistor having a polysilicon emitter

摘要

A method for manufacturing a bipolar junction transistor which includes the steps of forming spaced-apart base and collector regions in a surface region of a semiconductor substrate, forming a first insulating film on the semiconductor substrate, forming an emitter contact hole in the first insulating film, to thereby expose a first portion of the base region, forming a first conductive layer on the first insulating film and the exposed first portion of said base region, the first conductive layer being comprised of a first conductive material such as polysilicon, ion- implanting impurities into the first conductive layer, forming base and collector contact holes in a first resultant structure comprised of the first insulating film and the first conductive layer, to thereby expose a second portion of the base region spaced-apart from the first portion of the base region, and a portion of the collector region, respectively, forming a second conductive layer on a second resultant structure obtained by the preceding steps, the second conductive layer being comprised of a second conductive material such as in-situ doped polysilicon, and, patterning a third resultant structure comprised of the first and second conductive layers in such a manner as to form an emitter comprised of the first conductive material, an emitter contact in contact with the emitter, a base contact in contact with the exposed second portion of the base region, and a collector contact in contact with the exposed portion of the collector region, the emitter, base, and collector contacts being comprised of the second conductive material and being spaced-apart from one another.