Drain Current Model Including Velocity Saturation for Symmetric Double-Gate MOSFETs

A drain current model is developed for a symmetrically driven undoped (or lightly doped) symmetric double-gate MOSFET (SDGFET) under the drift–diffusion transport mechanism, with velocity saturation effects being included as an integral part of the model derivation. Velocity saturation effects are modeled by using the Caughey–Thomas engineering model with exponent $n = \hbox{2}$ . $I_{d}$– $V_{d}$, $I_{d}$– $V_{g}$, $g_{m}$ –$V_{g}$, and $g_{\rm DS}$–$V_{d}$ comparisons are made with 2-D device simulation results, and a very good match is found all the way from subthreshold to strong inversion. Gummel symmetry compliance is also shown.