Analytic Description of Short-Channel Effects in Fully-Depleted Double-Gate and Cylindrical, Surrounding-Gate MOSFETs

Short-channel effects in fully-depleted double-gate (DG) and cylindrical, surrounding-gate (SG) MOSFETs are governed by the electrostatic potential as confined by the gates, and thus by the device dimensions. The simple but powerful evanescent-mode analysis shows that the length lambda, over which the source and drain perturb the channel potential, is 1/pi of the effective device thickness for DG, and 1/4.810 of the effective diameter for SG, in excellent agreement with PADRE device simulations. Thus for equivalent silicon and gate oxide thicknesses, evanescent-mode analysis indicates that SG-MOSFETs can be scaled to 35% shorter channel lengths than DG-MOSFETs.