Impact of technology scaling on the 1∕f noise of thin and thick gate oxide deep submicron NMOS transistors

Abstract

This study discusses the composite effect of channel length and gate oxide thickness scaling, coupled with the effect of gate dielectric nitridation on the 1/f noise of minimum channel length NMOS transistors. These transistors have been taken from four advance CMOS technologies with dual gate oxide thickness. The result shows that the current noise spectral density SId of a thin gate oxide transistor increases by approximately 1.5 orders of magnitude when scaling from 350 nm to 130 nm. This increase is closely correlated to the changeover from thermal oxides to nitrided oxides from 250 nm and below. This work also investigates the effect of nitridation on thick gate oxide transistors and compares them to their architecturally equivalent thin gate oxide non-nitrided counterpart from 350 nm technology. The comparison reveals that nitridation has increased the SId of architecturally equivalent thick gate oxide transistors from 250 nm to 130 nm technologies by a maximum of 1.25 orders of magnitude. The experimental 1/f noise trends have been verified with simulations using the BSIM3v3 flicker noise model.