SILICON MOS TRANSCONDUCTANCE SCALING INTO THE OVERSHOOT REGIME

Simulations incorporating velocity overshoot are used to derive the dependence of deep-submicrometer MOS transconductance on low-field mobility mu(eff) and channel length L(ch). In contrast to strict velocity saturation, saturated transconductance departs from a strict mu(eff)/L(ch) dependence when overshoot is considered. Constraints on mu(eff) derived from conventional scaling laws together with strong mu(eff) dependencies in these regimes emphasize the importance of low-field inversion layer control and optimization. Transconductance in saturation is shown to approach a well-defined limit for very high mu(eff), proportional to L(ch)-2/3.