Ultraviolet annealing of thin Y_2O_3 films grown by pulsed laser deposition

摘要

We report on the results of ultraviolet (UV)-assisted annealing of thin Y_2O_3 films produced by pulsed laser deposition. An excimer XeCl laser was used for ablation of Y_2O_3 ceramic target. The films were grown on (001) SiO_2 substrates at 500 ℃ and oxygen pressure of 0.05 mbar. The effect of UV-assisted laser annealing on the structure, morphology, and optical properties was investigated. The UV-assisted annealing was performed by the same laser. The beam was directed parallel or toward the surface of the as-deposited films. The influence of the ambient gas (O_2 or N_2O) is explored. The ambient atmosphere has an influence on the preferential (cubic or monoclinic) phase of growth while it has no significant effect on the surface morphology. The absorption coefficient in the VIS range has a lower value for the films annealed with laser directed parallel to the surface independently on the gas environment. Annealing of the films with laser beam directed at the film surface slightly increases the refractive index, independently of the gas ambient.