Thin-film SOI p-MOSFET from epitaxial lateral overgrowth (ELO) with a 200 /spl Aring/ nitrided SiO/sub 2/ backgate and large /spl Delta/V/sub T,top/ Vs V/sub G,back/ for ultra low power

To achieve faster circuits with increased circuit density and reduced power, fully depleted (FD) dual-gated (DG) thin-film SOI-MOSFETs with an isolated buried backgate have been fabricated by using epitaxial lateral overgrowth (ELO) into SOI islands. Situated in an SOI island the fully depleted DG SOI MOSFET allows independent operation of both topgate and backgate, which is buried and totally isolated from all other devices. This provides a method to control the threshold voltage change of the top MOSFET with a bias on the backgate for fully-depleted devices. For example, the backgate can switch the top MOSFET to more 'on' for larger drive currents and to more 'off' for lower subthreshold leakage currents.