Microscopic mobility of electrons in weakly inverted MOSFETs

The apparent drop-off in measured mobility that occurs in MOS transistors near threshold is shown to be due a reduction in extracted conductance in the device. The reduction in conducatance is explained in terms of an increased drain to source channel resistance arising from lateral inhomogeneities in the gate oxide. It is shown that by correcting for the effect of inhomogeneity in the measured (average) mobility, no reduction is observed to occur in the microscopic mobility.