Improvement of structural and electrical properties of RF sputtered CCTO thin films by post-deposition annealing

Abstract

Calcium copper titanate (CCTO) sputtering target was fabricated by adopting solid state route. CCTO thin films were deposited on p-Si (100) substrates by RF magnetron sputtering technique at room temperature with RF power and deposition pressure of 105 W and 5 × 10-3 mbar, respectively. Post deposition annealing was carried out for the sputtered samples at different temperature ranging from 650 °C to 950 °C in air atmosphere. From X-ray diffraction, evolution of CCTO crystalline peaks was observed for thin film annealed at 950 °C. The surface morphology of the annealed thin film was found to be modulated with annealing temperature. Uniform distribution of microstructures was observed for the films annealed at higher temperature. Electrical properties of the annealed thin films were studied by fabricating Al/CCTO/Si MOS structures. The interface trap density (Dit) was calculated as 7.9 × 1010 eV-1cm-2 for the films annealed at 950 °C. Non-linear current-voltage characteristics have been observed for all the samples.