Performance analysis of vertical super-thin body (VSTB) FET and its characteristics in presence of noise

Abstract

In this work, a simulation-based performance study of vertical super-thin body (VSTB) MOSFET vis-a-vis various other MOS devices was presented. Use of appropriate doping profile greatly improves on to off current ratio (ION/IOFF) and subthreshold swing (SS). Improvement in input characteristics (ID–VGS) by gate–source (G/S) and gate–drain (G/D) overlap technique was explained with the help of electron density, mobility, and velocity of the device in off and on-states. Device performance shows negligible deviations in presence of different effects like stress, strain, tunneling, and velocity saturation. VSTB FET supports the downscaling of device size by offering excellent electrostatic integrity and low supply voltage operation. Values of off-current (IOFF), peak on-current (ION), peak transconductance (gm), SS, and DIBL for channel length (L) of 20 nm are 0.00145 nA/µm, 327.85 µA/µm, 974 µS/µm, 65.1 mV/dec, and 39.6 mV/V, respectively. Noise impact on device performance for three different noise sources (diffusion, generation–recombination/G–R, and flicker noise) was studied at two different frequencies (f = 1 MHz and 10 GHz). Maximum values of unit-gain cut-off frequencies (fTmax) obtained for channel lengths (L) of 20, 25, and 30 nm are 86.26, 80.47, and 76.22 GHz, respectively.