Structure of Ultrathin Epitaxial CeO₂Films Grown on Si(111)

Abstract

The structure of ultrathin epitaxial CeO 2 films grown on Si(111) by molecular beam epitaxy was investigated using highresolution Rutherford backscattering spectroscopy. The observed elemental depth profiles showed that there were oxygen defects in the CeO 2 films and the amount of oxygen defects was about 10%. The strain distribution in the CeO 2 film was measured using a channeling technique. It was found that the [100] axis of CeO 2 was tilted toward the ½2 1 1 1 1 direction by $0:7 . The observed tilt angle was more than twice larger than the expected tilt angle calculated from the lattice mismatch by assuming a pseudomorphic growth of CeO 2 . The present results suggest that the crystal structure of the CeO 2 film was changed from a cubic structure due to the oxygen defects.

Sol–gel deposited ceria thin films as gate dielectric for CMOS technology

“…The film's structure and interface properties depend upon deposition processes. Several deposition techniques have been reported in literature for the preparation of CeO 2 films on Si for CMOS devices, including sputtering (Wang et al 2001), vacuum evaporation (Inoue et al 1990), MBE (Joumori et al 2004), PLD (Karakaya et al 2006), MOCVD (Ami and Suzuki 1998), and E-beam evaporation (Inoue et al 1999), etc. All these techniques require high temperature treatments which usually induces a deterioration of the device performance and reliability.…”