Evidence that N2O is a stronger oxidizing agent than O2 for both Ta2O5 and bare Si below 1000 °C and temperature for minimum low-K interfacial oxide for high-K dielectric on Si

N2O is known to be the stronger oxidizing agent than O2 for the post-deposition annealing of Ta2O5·N2O should also be stronger than O2 for Si oxidation. However, NO released from N2O is also a nitridation agent which can produce silicon oxynitride at a temperature above 1000 °C and silicon oxynitride can be a diffusion barrier for oxygen. Below 1000 °C, SiO sublimation can make the comparison of N2O oxidation and O2 oxidation of Si difficult. Below 750 °C, N2O is obviously the faster oxidizing agent than O2 for bare Si. Furthermore, our results show that minimum interfacial SiOx, which has a low dielectric constant, occurs at about 800 °C or 950 °C for high-K metallic oxide gate insulator for future generations of CMOS because rapid thermal oxidation at these two temperatures can help to reduce leakage current or charge trapping by suppressing oxygen vacancies without too much low-K interfacial SiOx formation.