Oxynitridation using radical-oxygen and -nitrogen for high-performance and highly reliable n/pFETs

We report the importance of oxynitridation using radical-oxygen and -nitrogen to form a low-leakage and highly reliable 1.6-nm SiON gate-dielectric without performance degradation in n/pFETs. It was found that oxidation using radical-oxygen forms high-density 1.6-nm SiO₂, which is ten times more reliable than low-density SiO₂ formed by oxygen-ions in n/pFETs and is suitable for the base layer of nitridation. Nitrifying SiO₂ using radical-nitrogen facilitates surface nitridation of SiO₂, maintains an ideal SiON-Si substrate interface, and reduces the gate leakage current. The 1.6-nm SiON formed by radical-oxygen and -nitrogen produces comparable drivability in n/pFETs, has one and half orders of magnitude less gate leakage in nFETs, one order of magnitude less gate leakage in pFETs, and is ten times more reliable in n/pFETs than 1.6-nm SiO₂ formed by radical-oxygen.