BIPOLAR SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

An n-type buried layer is selectively formed in a surface region of a p-type semiconductor substrate. At least one insulating film is formed on the semiconductor substrate. A first opening is formed on the buried layer in the insulating film. An n-type polycrystalline silicon layer is formed in the first opening connected to the buried layer. A second opening is formed on the buried layer of the insulating film. An n-type monocrystalline silicon layer is formed in the second opening connected to the buried layer. A p-type base region is formed in the monocrystalline silicon layer and a collector region is formed in the remaining portion of the monocrystalline silicon layer. An emitter region is selectively formed in the base region.