Very-high fT and fmax silicon bipolar transistors using ultra-high-performance super self-aligned process technology for low-energy and ultra-high-speed LSI´s

Very-high f_T (up to 50 GHz) and f_max (up to 70 GHz) silicon bipolar transistors have been developed using Ultra-high-performance Super Self-aligned process Technology (USST). This technology is characterized by drastically-scaled lateral dimensions and shallow, heavily-doped extrinsic base structures. USST greatly reduces base-collector junction capacitance and base resistance, and hence makes f_max about twice as large as SST1C technology without vertical scaling. The fabricated ECL circuits show a minimum gate delay of 16.5 ps at a switching current of I_CS=1.0 mA/G