Short-channel effects on MOS transistor capacitances

A high-precision capacitance measurement method was applied to long-channel and short-channel MOS transistors. The capacitance characteristics of short-channel transistors were found to deviate significantly from their long-channel counterparts. The velocity saturation effect, vertical-field mobility- degradation effect, channel-length modulation effect, source-and-drain series resistance effect, and channel-side fringingfield have to be taken into account in modeling the small-geometry transistors. Modeled results including the short-channel effects showed good agreement with the measured results.