Statistical worst-case MOS parameter extraction

A method is presented by which realistic worst-case parameter sets can be calculated. The method uses a statistical model from which all main MOS parameter values are calculated from four independent parameters. The statistical model, which is derived from a large number of measurements, is used to account for the correlations between the model parameters. The calculated worst-case parameter sets have been verified against measurements and have been shown to be accurate in predicting the worst-case current levels for both n-channel and p-channel devices.