Preparation and characterization of Al₂O₃ film deposited by RF sputtering and plasma enhanced atomic layer deposition

In this paper, the authors have investigated the structural and electrical properties of thin film of Al₂O₃ deposited by radio-frequency sputtering and plasma enhanced atomic layer deposition (PEALD) technique. Different deposition and process parameters for the sputtered and PEALD Al₂O₃ films were chosen to investigate their effect on the structural and electrical characteristics of the film. X-ray diffraction result shows the dominant peak of Al₂O₃ in both the cases at 2θ = 56° indicating (312) film orientation. Multiple angle analysis of sputtered and PEALD Al₂O₃ film shows a refractive index in the range of 1.70–1.74 and 1.65–1.69, respectively. Electrical characteristics indicate that the device fabricated by PEALD and annealed at 425 °C shows the positive flatband voltage of 3.5 V and improved leakage behavior as compared to the film deposited by sputtering.