Effect of the back gate conduction on 0.25 μm SOI devices

Abstract

This paper examines the off-state leakage current of 0.25 μm SOI devices for low-voltage and low-power applications. From both electrical measurements and two-dimension simulations (with impact ionization) the off-state leakage current is found to be due to the back gate conduction arising from the combined drain induced barrier lowering and floating body charging effects. Comparison between thin and thick buried oxides shows that the use of a thin buried oxide is limited by the presence of fixed charge density in the buried oxide, a high doping level is thus required to prevent any parasitic conduction at the back interface.