Highly oriented crystalline Ga2O3 thin films were fabricated at room temperature (RT) by excimer laser annealing. Amorphous Ga2O3 thin films were grown on alpha-Al2O3 (0001) substrates at RT by the pulsed laser deposition method using a focused KrF excimer laser and a sintered beta-Ga2O3 target. Amorphous precursor films were irradiated by a non-focused KrF excimer laser (100-250 mJ/cm(2)) at RT. The results of x-ray and reflection high-energy electron diffraction measurements indicated that highly (101)-oriented crystalline beta-Ga2O3 thin films were obtained after RT laser annealing. The optical bandgaps of the crystalline thin films were approximately 4.7-4.9 eV, as determined from the UV/Vis transmittance. The film surfaces after laser annealing revealed slight planar grain growth, indicating a high degree of crystallinity and showed the root mean square roughnesses of 0.28-0.48 nm. (C) 2015 Elsevier B.V. All rights reserved.