Patent ID: 6797580
Filing Date: 2004-09-28
Classification: H01L

Abstract:
A method for fabricating a bipolar transistor in a BiCMOS process, said method comprising steps of:forming an emitter window stack by sequentially depositing a base oxide layer and an antireflective coating layer on a top surface of a base of said bipolar transistor, said emitter window stack not comprising a polysilicon layer; etching an emitter window opening in said emitter window stack; depositing an emitter layer in said emitter window opening and over said antireflective coating layer; etching said emitter layer to form an emitter of said bipolar transistor; etching a first portion of said base oxide layer not covered by said emitter using a first etchant so as to cause said first portion of said base oxide layer to have a thickness less than a thickness of a second portion of said base oxide layer covered by said emitter.