Small Signal Modeling of Scaled Double-Gate MOSFET for GHz Applications

The limits on scaling suggest the technology advancement for the solid-state devices. The double-gate (DG) MOSFET has emerged as an alternative device structure due to the certain significant advantages, i.e. increase in mobility, ideal sub-threshold slope, higher drain current, reduced power consumption and screening of source end of the channel by drain electric field (due to proximity to the channel of the second gate, which reduces the short channel effects). In this work, we have analyzed the double-gate MOSFET (undoped body because the doping rapidly varies the threshold voltage). The analytical expressions has been derived on the basis of surface potential model, which has been further used to yield the potential distribution, drain current, conductance and trans-capacitance. This illustrate the volume inversion effect is quite significant in this device upto the certain range of dimensions. In addition to this, we have analyzed the performance of symmetric DG MOSFET based on the circuit design prospective using S-parameters.