The effects of injection current density and temperature on time-dependent dielectric breakdown (TDDB) of low-pressure thermally reoxidized-nitrided oxides (RNO's) and fluorinated oxides (FO's) with equivalent oxide thicknesses of 100 A were examined. Time to breakdown for RNO was found to be improved over that for thermal oxide while both the impact ionization coefficient and the activation energy of lifetime are comparable to those of control oxide. On the other hand, no obvious TDDB improvement was observed for FO. This observation, in conjunction with the results for charge trapping measurements at different temperatures, indicates that the lifetime improvement for RNO's might be due to the reduced charge traps in these films. I-V ramp tests have shown that RNO has a comparable defect density to that of control oxide.