NEW SHORT-CHANNEL N-MOSFET CURRENT-VOLTAGE MODEL IN STRONG INVERSION AND UNIFIED PARAMETER EXTRACTION METHOD

Abstract

We propose a new semi-empirical strong inversion current-voltage (I-V) model for submicrometer n-channel MOSFET's which is suitable for circuit simulation and rapid process characterization. Our model is based on a more accurate velocity-field relationship in the linear region and finite drain conductance due to channel length modulation effect in the saturation region. Our parameter extraction starts from the experimental determination of the MOSFET saturation current and saturation voltage by differentiating the output characteristics in a unified and unambiguous way. We use these results in order to extract the device and process parameters such as the effective electron saturation velocity and mobility, drain and source series resistances, effective gate length and characteristic length for channel length modulation, and short-channel effects systematically. The deduced values agree well with other independent measurements. We report the results of experimental studies of wide n-MOSFET's with nominal gate lengths of 0.8, 1.0, and 1.2-mu-m fabricated by n-well CMOS process. The calculated I-V characteristics using the extracted parameters show excellent agreement with the measurement results. The salient feature of our approach is that it allows the automatic parameter extraction in a systematic and unified manner, which is extremely versatile for statistical yield analysis due to parameter variation.