A method for manufacturing a semiconductor apparatus is disclosed. The apparatus comprises double poly bipolar transistors and double poly metal oxide semiconductor (MOS) transistors. The bipolar transistors and the MOS transistors are manufactured in a unified process in which a first polysilicon layer (Poly1) is doped to form the extrinsic bases in the bipolar transistors and to form the gates in the MOS transistors. A second polysilicon layer (Poly2) is doped to form emitters in the bipolar transistors and to form the sources and drains in the MOS transistors. The method of the invention minimizes the number of manufacturing process steps.