Potential barrier for oxidation of HfSi₂/Si(111) surface studied with super sonic O₂ molecular beam

Abstract

The oxidation processes of Hf disilicide on Si(111) substrate [HfSi₂/Si(111)] after supersonic O₂ molecular beam (SOMB) irradiation were investigated with synchrotron radiation soft X-ray photoelectron spectroscopies of Hf 4f, Si 2p, and O 1s core-levels. A direct dissociation process of the impinging O₂ will be discussed from the oxidation progression depending on SOMB kinetic energy (KE) increase. In addition, the potential barrier for oxidation of HfSi₂/Si(111) will be also demonstrated from a stepwise growth of the total area of Hf oxide species depending on KE of SOMB.