In this letter, we report on the reaction between Si and N2 in the temperature range of 760-1050°C, in a rapid thermal processing chamber. Gas phase impurities such as H2O, O2, and H2, which can outgas from the cold walls of the chamber, mediate the Si/N2 reaction, resulting in the formation of SiOxNy. The oxynitridation can be explained by equilibrium chemical thermodynamics, in contrast to the case of oxynitridation using N2O or NO, where the nitrogen is incorporated under nonequilibrium conditions. Using nuclear reaction analysis, we have measured nitrogen contents as high as 2.5×1015 N/cm2 (the equivalent of more than 3 monolayers) in these new dielectrics. They can be reoxidized to form ultrathin (2 to 3 nm) dielectrics.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)