The effects of rapid thermal reoxidation (RO) on the hot-carrier immunity of 0.6 μm MOSFETs with thin (∼13 nm) rapidly thermal nitrided (RTN) oxides is reported. The hot-carrier immunity is evaluated in terms of the threshold voltage shift, ΔVth, and the transconductance degradation, ΔGm/Gm(0), under worst case hot-carrier stress condition (with maximum substrate current Isub, max). It is found that subsequent in-situ RTO of RTN oxides enhances the hot-carrier immunity, and this enhacement increases with RTO temperature. In addition, the natures of hot-carrier-induced damages in MOSFETs with RTO/RTN gate oxides are different from that with thermal SiO2.