Extraction of experimental mobility data for MOS devices

MOS surface mobility is a fundamental material and device property which has been extensively studied both theoretically and experimentally. This work reports on a new technique for extracting surface mobility data from experimentally measured I-V data on large area MOS devices. The approach employs a least squares curve fitting technique for combining theoretical models of inversion layer charge and surface mobility to obtain an accurate value of surface threshold voltage. An accurate model of inversion layer charge is then used to calculate the experimental mobility. The extraction technique gives high field values of mobility which compare very closely with previously reported extraction approaches but gives more accurate low field values due to an improved model for inversion layer charge. A very important feature of the technique is the ability to obtain data on individual components of surface scattering such as interface scattering density and surface roughness coefficient. These individual parameters are very valuable when comparing the effects of changes in surface preparation techniques on MOS surface mobility.