Influence of post-deposition annealing on the microstructure and properties of Ga2O3:Mn thin films deposited by RF planar magnetron sputtering

Thin films of Ga2O3:Mn have been deposited on silicon (100) substrates without intentional heating by radio frequency (RF) planar magnetron sputtering from a Mn-doped Ga2O3 target in an oxygen-argon mixture atmosphere. Microstructure and properties of the deposited Ga2O3:Mn films were systematically investigated as a function of the post-deposition annealing temperature in the range between 500 A degrees C and 1200 A degrees C. X-ray diffraction (XRD) measurements showed that the as-deposited Ga2O3:Mn films were of an amorphous structure in nature. The Ga2O3:Mn films became crystalline by the post-deposition annealing above 800 A degrees C and the crystallinity of the films was continuously improved up to the annealing temperature of 1200 A degrees C. It was shown that the annealed Ga2O3:Mn films possessed a monoclinic beta-Ga2O3 phase having a textured structure with (400) and (-401) crystallographic planes oriented preferentially parallel to the substrate surface. The lattice parameters of the monoclinic beta-Ga2O3 phase in the 1200 A degrees C annealed Ga2O3:Mn films were measured to be a = 12.152 , b = 3.043 , and c = 5.785 .