A selective-epitaxial SiGe HBT with SMI electrodes featuring 9.3-ps ECL-gate delay

Abstract

A selective-epitaxial SiGe base heterojunction bipolar transistor (HBT) with self-aligned stacked metal/IDP (SMI) electrodes is proposed. The SiGe-base structure, self-aligned to the 0.1-/spl mu/m-wide emitter, effectively reduces collector capacitance and SMI electrodes provide low parasitic resistances. A BPSG/SiO/sub 2/-refilled trench was introduced to reduce the substrate capacitance. A 9.3-ps delay time in a differential ECL ring oscillator was achieved.