Evolution of microstructural and electrical properties of sputtered HfO2 ceramic thin films with RF power and substrate temperature

Hafnium oxide (HfO2) ceramic thin films were deposited on p-type silicon substrate by radio frequency magnetron sputtering at various RF powers and substrate temperatures. The morphological and electrical properties of the sputtered films were investigated and a correlation between the surface and interface properties of the HfO2 films was established with the variation of sputtering parameters. The evolution of monoclinic structure of the hafnium oxide thin films was observed by XRD studies. The surface of the HfO2 ceramic thin films became smooth with the decrease in grain size for higher power and growth temperature. The characteristic FTIR absorption peaks in the range from 550 cm−1 to 900 cm−1 depicted the formation of Hf–O bond for all the samples. The oxide charge density and leakage current density was found to be increased with the increase in RF power and substrate temperature, which was mainly due to the evolution of smaller grains. HfO2 thin films, grown at room temperature with a RF power of 150 W, have shown better electrical properties.