Self-Aligned Technology for Sub-100nm Deep Base Junction Transistors

The problems in scalling down of modern advanced polysilicon self-aligned transistors are brief1y discussed. Then, a novel self-aligned technology is proposed to solve the problems. The newly developed BSA (BSG Self-Aligned ) technology is featured by the use of CVD-BSG Film as a sidewall spacer as well as a diffusion source to form both intrinsic base and p⁺-connecting regions, simultaneousely. The fabricated transistor having 40nm deep emitter-base junction and sub-100nm collector-base junction shows 70 of hFE and 7V of BVCEO, respectively.