A 30-GHz f/sub T/ quasi-self-aligned single-poly bipolar technology

In this paper, we report the state-of-the-art results obtained in quasi-self-aligned (QSA) single polysilicon NPN bipolar transistors fabricated within a low-complexity 0.5-/spl mu/m CMOS process. Our devices demonstrate nearly ideal static characteristics and very good frequency performance. In fact, the obtained 30-GHz maximum f/sub T/ and 4.1 V breakdown voltage are comparable to the best reported results for single-poly self-aligned (SA) transistors. Some details of the technological process as well as statistical measurements performed on the different optimization splits are presented. The f/sub T/ and f/sub max/ on-wafer high-frequency measurements are discussed in terms of reproducibility, sensitivity to process parameters, and device geometry.