BSA Technology for sub-100nm deep base bipolar transistors

This paper will describe a novel self-aligned technology, BSA (BSG Self-Aligned) technology. The BSA technology makes it possible to realize the self-aligned bipolar transistors having sub- 100nm deep base junction and to solve the problems in lateral and vertical scaling down of self-aligned transistors. The BSA technology is featured by the use of BSG film not only as a sidewall spacer but also as a diffusion source to form both the intrinsic base and p⁺-link regions by rapid thermal annealing (RTA), simultaneously. The typical BSA transistor having sub-100nm deep base junction showed 70 of hFE, 7V of BVCEOand 3V of BVEBO, respectively.