A Silicon Spacer Self-Aligned Contact Bipolar Technology for High Speed Application

A high speed bipolar technology utilizing the silicon spacer as the self-aligned base contact is presented. The self-alignment techniques have significantly improved the high speed bipolar device performance by reducing the base parasitic capacitance Cbe and base resistance Rbx. Several self-aligned contact techniques have been proposed both for bipolar and MOSFET technologies. Many of the schemes are rather complicated for today's manufacturing environment. In this paper, we propose a new self-aligned contact process for the bipolar technology with very simple process steps and without involving non-conventional materials.