"Universal" effective mobility of empirical local mobility models for n- and p-channel silicon MOSFETs

Abstract

Several experimental investigations have shown that the measured effective mobility falls on one common curve (the Universal Mobility Curve) independent of the substrate doping density and the source-to-substrate bias if the effective mobility is plotted vs the effective field. This paper reports on the relationship between the effective field (a non-local electric field mobility model) and the local mobility models employed in drift-diffusion device simulators. Using a drift-diffusion device simulator which implements several mobility models in the same simulator, we show that not all local mobility models agree with the empirical universal mobility behavior for both n-channel and p-channel MOSFETs when the simulated results are interpreted as "experimental" data. Furthermore, some local mobility models do not agree with the universal mobility behavior if the device has compensated channel doping (such as a typical CMOS p-channel device). © 1993.