Annealing effects on properties of Ga_2O_3 films deposited by plasma-enhanced atomic layer deposition

摘要

We investigated annealing effects on the Ga2O3 thin films deposited on c-sapphire by plasma-enhanced atomic layer deposition. A metastable Ga2O3 films was deposited on c-sapphire substrate by PEALD with high plasma power at 250 degrees C. The ((2) over bar 01) preferred orientation beta-Ga2O3 films were obtained after annealing in oxygen atmosphere. Structure and surface analysis revealed that the annealed films had more fine-grained surface features. The film annealed for 2 h exhibited the best crystallinity. The bandgap of the as-deposited and annealed films for 2 h were 4.56 and 4.97 eV, respectively. The process of high-temperature annealing contributed gallium, oxygen atoms to obtain enough energy to migrate to the suitable location and increased the vigilance of crystallinity. (C) 2018 Elsevier B.V. All rights reserved.