Abstract: A method of forming a bipolar junction transistor using a CMOS process that includes performing a high voltage deep well and drive-in process in a semiconductor substrate having a predetermined substructure; performing a local oxidation of silicon (LOCOS) process; performing an Nbase and Pbase process on the resulting structure; forming logic N well and P well and annealing the logic wells; forming a poly gate and sequentially forming NMOS/PMOS LDD source/drain; and forming N+/P+ source/drain, annealing the source/drain and sequentially performing a CONT˜PAD process.