A novel approach for modeling threshold voltage of MOSFET using CV characteristics

In this paper, a new threshold voltage model of a MOSFET (metal oxide semiconductor field effect transistor) based on MOS capacitance property has been presented. The MOS capacitance variation in the depletion ragion is taken as the basis for the threshold voltage modeling. A change in the space charge width brings a change in the voltage across the depletion layer and also the input capacitance. Dividing the whole space charge width into smaller depleted layers, then summation of the individual voltages of each depleted layers at the maximum width gives the threshold voltage of the MOSFET. For the sake of simplicity ideal MOS capacitor has been considered. The accuracy of the model is verified by numerical calculations taken for a range of dopant concentrations from 10¹³ to 10²⁰ atoms/cm³, and the results are found to be in reasonable agreement with the value obtained using the Shockley´s model.