Threshold Voltage Extraction of nMOSFET Devices in Photovoltaic Inverters

Abstract

Abstract In this paper, the electrical characteristics of nMOSFET devices at room temperature are measured, and the threshold voltage is extracted by three different methods according to the I-V transfer characteristic curve of the nMOSFTE devices. The applicability of the three methods and the extraction results are analyzed and compared. The conclusions indicate that: (1) the maximum transconductance extraction method is similar to the tangential extrapolation extraction method, both of which eliminate the influence of mobility degradation and parasitic capacitance effect. The second order derivative extraction methods include the fluctuation factors in the measured results, and has a larger error on the extracted threshold voltage; (2) Compared with the maximum transconductance extraction method, the errors of extracting threshold voltage using tangential extrapolation method is larger because mobility attenuation, sourcing-drain series resistance and tangential point is difficult to determine accurately are ignored. (3) In comparison, the threshold voltage extracted by the maximum transconductance method is more accurate and easy to achieve.