A 1.5µm high-energy ion implanted BiCMOS process is proposed. This process offers NMOS, PMOS, vertical npn transistors and VIPMOS-EPROM devices. The process structure is modular in order to achieve CMOS and bipolar transistors in uncompromised forms. Consequently, the N-well and collector regions are defined separately. Conflicting requirements for the collector doping profile have been optimized towards practical electrical device characteristics