Symbolic Layout for Bipolar and MOS VLSI

VLSI design requires design methodologies which are tailored to the implementation technology. Symbolic layout has been addressed in the past for MOS technology, while bipolar technology has largely been ignored. This paper describes a novel symbolic design technique which addresses both bipolar and MOS technologies. The technique allows the designer to symbolically layout nMOS, CMOS, and bipolar circuit structures. The symbol set is used for both MOS and bipolar devices in an integrated and consistent way. It is closely related to the mask layout information rather than circuit schematics. Thus, it allows the creation of any circuit structure based on bipolar, MOS, CMOS, BIMOS, and BICMOS technologies. Design examples are given.