A three-dimensional CMOS design methodology

A technology-updatable design methodology for three-dimensional (3-D) CMOS circuits has been developed. Four levels of abstraction have been implemented with topographical congruence: 1) technology level, 2) mask level, 3) transistor level, and 4) logic level. A novel transistor level symbolic representation is introduced which emphasizes the three-dimensional nature of the circuits. A number of design examples is presented.