Nitrogen engineering of ultrathin oxynitrides by a thermal NO/O2/NO process

Abstract
The paper discusses nitrogen engineering of ultrathin (<5 nm) oxynitride gate dielectrics. The dielectric film that we have aimed for has two nitrogen enhanced layers: one at the SiO2/polysilicon interface to retard boron diffusion from the gate, and a smaller one peaked at the Si/SiO2 interface to increase the hot electron degradation resistance. We were able to produce this dielectric by a thermal (NO/O2/NO) process, aided by an understanding of the kinetics and thermodynamics of nitrogen incorporation in SiO2.