Changes in electrical and structural properties of indium oxide thin films through post-deposition annealing

Abstract The annealing effects on the electrical properties and microstructures of indium oxide (In 2 O 3 ) thin films were investigated. The In 2 O 3 thin films with the thickness of about 150 nm were annealed at various temperatures ranging from 100 to 600 °C in air after the sputtering deposition. It was found that the carrier density of the In 2 O 3 thin films decreased with increasing in the annealing temperature and then started to increase at a certain temperature. This indicated that the reduction of the In 2 O 3 thin films was promoted at high annealing temperature. The Hall mobility of the In 2 O 3 thin films increased through the reduction; furthermore, the d -spacing of the In 2 O 3 crystal lattice plane tended toward ideal value. It can be believed from these results that one of the principal electron scattering in the In 2 O 3 thin films is attributed to excess oxygen atoms that expand the d -spacing.