Capacitor for a BiCMOS device

摘要

The invention provides an improved BiCMOS device and a method of fabricating such a BiCMOS device which requires fewer process steps than known fabrication methods. In one embodiment, the invention provides a method of forming an interpoly capacitor in a BiCMOS device which maintains the thickness of the interpoly dielectric in the capacitor while a window is etched for the emitter in a bipolar transistor. The method includes the use of a thin polysilicon layer overlying the oxide layer, which protects the oxide from etching while the emitter window is etched.