New method for verification of analytical device models using transistor parameter fluctuations [MOSFETs]

In this work device parameter fluctuations are considered for verification of analytical device models. We focus on the (WL)/sup -1/2/-dependence of the standard deviation of the threshold voltage /spl sigma//sub Vt/ [1-6]. Besides the known contribution from doping variations, an explicit channel length dependence enhances substantially the (WL)/sup -1/2/-curve. Oxide thickness variation is shown to have minor influence on the V/sub T/-fluctuation and the contribution of mobility fluctuation is completely negligible for a 0.5 /spl mu/m process. It has been found that a percolation model for the current paths through the device can give full account of the experimentally measured values of /spl sigma//sub Vt/.