A 0.18-(mu)m RF SiGe BiCMOS technology with collector-epi-free double-poly selfaligned HBTs

This paper describes an RF SiGe BiCMOS technology based on a standard 0.18-(mu)m CMOS process. This technology has the following key points: 1) A double-poly self-aligned SiGe-HBT is produced by adding a four-mask process to the CMOS process flow-this HBT has an SiGe epitaxial base selectively grown on an epi-free collector; 2) two-step annealing of CMOS source/drain/gate activation is utilized to solve the thermal budget tradeoff between SiGe-HBTs and CMOS; and 3) a robust Ge profile design is studied to improve the thermal stability of the SiGe-base/Si-collector junction. This process yields 73-GHz f/sub T/, 61-GHz f/sub max/ SiGe HBTs without compromising 0.18-(mu)m p/sup +//n/sup +/ dual-gate CMOS characteristics.