Self-aligned bipolar fabrication process.

摘要

Bipolar transistors are made by: forming a substitute emitter on a substrate; depositing polysilicon about the substitute emitter; removing the substitute emitter, and implanting the base through the resulting gap; forming dielectric spacers on the sidewalls of the opening; depositing polysilicon in the remains of the opening; and diffusing dopant from the polysilicon into the substrate to form a shallow emitter.