Influence of laser treatment on the electrical properties of plasma-enhanced-atomic-layer-deposited TiO2 thin films

TiO2 dielectric films with 3 8 nm thickness were grown on Si (100) substrates at 200 degrees C by plasma-enhancedatomic-layer deposition. Laser-irradiated TiO2 films maintained an amorphous phase similar to as-grown films and showed an increase in permittivity and leakage current density with increasing laser powers and the number of laser shots at constant laser power. Laser-irradiation of TiO2 films at room temperature produced oxygen vacancies at the film surface and new Ti3+ valences. The electrons and space charges produced through the defect chemistry increased the leakage current density and permittivity in laser-irradiated TiO2 films, respectively. The dielectric and electrical properties of the laser-irradiated TiO2 films were completely recovered to correspond with those of as-grown films by post-annealing at 300 degrees C for 5 min in O-2 ambient.