AN ANALYTICAL BACK GATE BIAS DEPENDENT SUBTHRESHOLD SWING MODEL FOR ACCUMULATION-MODE P-CHANNEL SOI MOSFETS

An analytical back gate bias dependent subthreshold swing model of the accumulation-mode p-channel SOI MOSFETs is derived using the exponent ial dependence of the carrier concentrations on the potential through the silicon film. The subthreshold swing is shown to be proportional t o the reciprocal of the derivative of the minimum potential through th e silicon film with respect to the front gate voltage. The subthreshol d swing is compared to that in the enhancement-mode devices, and its d ependencies on device parameters and back gate bias are studied. Based on the model, a method of extraction of front and back interface trap densities in these devices from subthreshhold swing is suggested.