Dielectric properties of nitric oxide-annealed gate oxides grown on nitrogen-implanted silicon substrates

Abstract

The characteristics of nitric oxide (NO)-annealed nitrided gate oxides grown on nitrogen-implanted silicon substrates (NIS) were studied in this paper. It was found that nitrogen accumulation occurred near the interface after NO-annealing, while NIS-grown nitrided oxide produced a uniform nitrogen distribution in the dielectric bulk. Moreover, it was found that the dielectric reliability is strongly dependent on the dosages used for NIS preparation. NIS with dosages smaller than 10(14) cm(-2) was found not to suppress the oxidation rate and to degrade the dielectric reliability. On the other hand, the samples with a dosage of 10(15) cm(-2) not only exhibited a significantly reduced oxidation rate, making it suitable for growing oxides of multiple thicknesses in sub-3 nm technologies meeting the Systems on Chip requirement, but also improved the dielectric reliability. NO-annealed NIS-grown nitrided oxides depict superior dielectric reliability and this technique appears to be suitable to replace the traditional SiO2 at 0.13 mu m technology node and beyond. (c) 2006 Elsevier B.V. All rights reserved.