Gate oxides in 50 nm devices: thickness uniformity improves projected reliability

Abstract

We demonstrate that reliability projections can be improved significantly if oxide thickness uniformity is improved. Our results include a Weibull slope of 1.38 for an extremely uniform 1.6 nm oxide, and also a steeper voltage scaling factor than has been used in the past. Transistors with 50 nm gate-length and /spl sim/1.5 nm oxides exhibit soft breakdown, suggesting that it may be possible to relax current reliability specifications.