Comparative Study of Double Gate and Silicon on Insulator MOSFET by Varying Device Parameters

Abstract

A comparative study of the single gate MOSFET (SG MOSFET), double-gate MOSFET (DG MOSFET) and silicon-on-insulator MOSFET (SOI MOSFET) is done using MOSFET simulation tool. Device simulation is done by varying different physical parameters of the device structure such as oxide thickness, channel length, temperature and different gate electrodes. Contour plots of SOI and DG MOSFET for electron concentration and potential at initial and final bias are simulated. The drain current vs gate voltage (Id-Vg) characteristics performance simulations show that DG MOSFET is better than SOI MOSFET for different oxide thickness and channel length. It was further noticed that with an increase in the oxide thickness, drain current decreases for DG and SOI MOSFETs. When oxide thickness is reduced from 10 to 7 nm keeping all other parameters same, in DG MOSFET drain current increased by 49.49 % and in SOI MOSFET drain current increased by 66.6 %. When channel length is reduced from 80 to 75 nm in DG MOSFET drain current increased by 1.35 % and in SOI MOSFET drain current increased by 2 %. The performance simulations show that aluminium (Al) gate electrode is better than n+ poly silicon (Si) and tungsten (W) for every MOSFET devices. With respect to aluminium gate electrode in DG MOSFET, for n+ poly Si and tungsten, drain current decreased by 3.89 and 30.5 %, respectively and in SOI MOSFET, for n+ poly Si and tungsten, drain current decreased by 3.84 and 34.61 %, respectively.