Patent ID: 6815301
Filing Date: 2004-11-09
Classification: H01L

Abstract:
A method for fabricating a bipolar transistor, comprising:a first step of implanting, along the normal direction of the principle surface of a first-conductive-type semiconductor single crystalline substrate, ions of a second-conductive-type first impurity into the semiconductor single crystalline substrate to form a second-conductive-type collector layer; a second step of implanting, along a direction tilted from the normal direction, ions of a second-conductive-type second impurity into the semiconductor single crystalline substrate at a higher injection energy than that in the ion implantation of the first step to form a second-conductive-type buried collector layer in a lower portion of the collector layer; and a third step of forming each of a first-conductive-type base layer and a second-conductive-type emitter layer in a predetermined region of a surface portion of the collector layer.