On the effective mobility for electrons in MOS inversion channels

The results of this paper are twofold. First, the relation between the local mobility model /spl mu//sub 1/(E/spl I.oarr/) and the long channel measured effective mobility /spl mu//sub eff/(V/sub gs/) is investigated. This allows one to find a mathematical condition which any /spl mu//sub 1/ model in a 2D numerical device simulator should fulfil. Here, we extend our previous work by using this condition to find the model parameters of a MEDICI /spl mu//sub 1/ model. We reach very good quantitative agreement with an experiment for a complete L-array, even for poly lengths down to 0.08 /spl mu/m. Secondly, it is advocated that the long channel effective mobility cannot be used to model short channel devices. We show experimentally and theoretically that the short channel effective mobility depends on the channel length due to the high internal drain-channel built-in field.