Bipolar transistor in bipolar-CMOS technology

A process of forming an integrated circuit containing a bipolar transistor and an MOS transistor, by forming a base layer of the bipolar transistor using a non-selective epitaxial process so that the base layer has a single crystalline region on a collector active area and a polycrystalline region on adjacent field oxide, and concurrently implanting the MOS gate layer and the polycrystalline region of the base layer, so that the base-collector junction extends into the substrate less than one-third of the depth of the field oxide, and vertically cumulative doping density of the polycrystalline region of the base layer is between 80 percent and 125 percent of a vertically cumulative doping density of the MOS gate. An integrated circuit containing a bipolar transistor and an MOS transistor formed by the described process.