Physical insight into fractional power dependence of saturation current on gate voltage in advanced short channel MOSFETs (alpha-power law model)

The physical origin of the fractional power dependence of MOSFET drain current on gate voltage, namely the α-power law model that has been considered as a fully empirical model, is analytically investigated. For this purpose, we have developed a new physics-based analytical drain current model. Using this model, we prove that the saturation current can be simplified in the form of B·(V_g-V_TH)^α, α-power law model. The physical interpretations of α, B, V_TH are elucidated, and their analytical expressions are given in terms of MOSFET parameters. Since the α-power model is compact and physics-based, it allows circuit designers to easily estimate the power dissipation and the gate delay time in a predictable manner.