mos device modelling

Modeling the MOS device consists in writing a set of equations that link voltages and currents, in order to
simulate and predict the behavior of the single device [Shockley] and consequently the behavior of a
complete circuit. A considerable research and development effort has been dedicated in the past years to
modeling MOS devices in an accurate way. Many books have been published over the years about the
semiconductor physics and semiconductor device modeling. The most common references are [Tsividis],
[Sze], [Lee] and recently [Liu]. For MOS devices, one of the key objectives of the model is to evaluate the
current Ids which flows between the drain and the source, depending on the supply voltages Vd,Vg,Vs and