Post-Etch Cleaning after Dry Etching the Emitter Windows to Improve the Bipolar Characteristics in a 0.5μm BiCMOS Process

The opening of 0.5μm wide emitter windows in the base oxide to fabricate quasiselfaligned poly emitter bipolar transistors involves a dry oxide etching. This paper shows how appropriate post-etch cleaning substantially improves the base current characteristics and the emitter resistance of poly emitter bipolar transistors of a 0.5μm BiCMOS process.