Reliability retention in in situ pyrolytic-gas passivated ultrathin silicon oxide gate films oxidized at 700 °C

Abstract

The oxidation temperature dependence of the reliability of in situ pyrolytic-gas passivated (PGP) ultrathin silicon oxide gate films was investigated. PGP uses a little pyrolytic N2O gas during ultradry oxidation with pure O2 at less than 1 ppb humidity. The reliability of the PGP films oxidized at 700–900 °C was evaluated by measuring the time-dependent dielectric breakdown (TDDB) lifetime (TTDDB) and interface state density (Dit). It was found that the reliability for the PGP films oxidized at the low temperature of 700 °C is much like the others. That is, TTDDB of the 700 °C PGP films barely decrease in comparison with those of the 800–900 °C PGP ones and their Dit are less than 7×1010 eV−1 cm−2. This indicates that PGP has a potential for application to future low-temperature processes for fabricating nanometer-scale electronic and optoelectronic devices.