Improved Determination of Surface Mobility at Mosfets with Thin Gatl Oxide

We propose an extraction procedure to determine the surface mobility of MOSFE Is based on the drain current equation after Pao and Sah. This model is extended to consider short channel effects and the charge of interface states in nonequilibrium. At low drain voltage the calculated drain current is compared to two-dimensional simulation results. Excellent agreement is found for samples with oxide thickness dotn to 20 nm even for MOSFETs with channel length of submicron dimensions. Extracted mobility values are in good agreement with experimentl results of time-of-flight measurements and are found to be independent from oxide thickness. At low oxide thickness the surface mobility extraction using the charge sheet model leads to remarkable different values.