Base-emitter voltage mismatch in a pair of self-aligned bipolar transistors

摘要

The base-emitter voltage mismatch. Delta V/sub BE/ for a pair of double polysilicon self-aligned bipolar transistors is studied. In the low emitter current range, the base peripheral effect is a dominant factor affecting Delta V/sub BE/. Since the base peripheral component caused by the lateral encroachment of the extrinsic base on the emitter region becomes important, Delta V/sub BE/ increases as sidewall spacer width decreases. On the other hand, in the high current range, the emitter contact resistance is dominant and Delta V/sub BE/ increases due to increased mismatch of emitter resistance.