Femtosecond pulsed laser deposition of highly oriented cerium (IV) oxide thin films with background oxygen gas
We report the femtosecond pulsed laser deposition (fs-PLD) of highly oriented cerium (IV) oxide (CeO2) thin films with background oxygen (O2) gas. The CeO2 films are deposited on Si(100) substrates at different O2 gas pressures of 30 to 90 mTorr and then annealed at 1000°C in ambient air. All films exhibit CeO2 reflections along with few cerium (III) oxide (Ce2O3) reflections. These Ce2O3 reflections are attributed to the post-deposition heat treatment due to their presence regardless of the O2 gas pressure. Moreover, although the films have lattice constants similar to that of the CeO2 target, a high O2 gas pressure results in smaller mean crystallite sizes and a different preferential orientation. Our findings suggest that using a lower background O2 gas pressure is sufficient for the fs-PLD of highly oriented CeO2 thin films.