Study of the effect of temperature on optical and topographical properties of RF ‎Magnetron Sputtered ZrO2 thin films‎

Abstract

In this paper, ZrO2 thin films were grown on glass substrates using RF magnetic sputtering method. In ‎three separate experiments, three samples of ZrO2 film were prepared at various temperatures. Three ‎temperatures of 25 ̊C (laboratory temperature), 150 ̊C and 250 ̊C were selected for three samples, respectively. Except for temperature, other parameters ‎such as pressure, film growth rate, substrate to target distance and deposition time were the same for all ‎three samples. Optical properties and morphology of the samples were investigated. The morphology of ‎the samples was determined by atomic force microscopy (AFM) images and the ‎transmittance was measured using optical spectroscopy. The optical constants of the films were also ‎calculated using their spectrum. The results show that the effect of temperature is especially evident on ‎the optical properties of the films. As the temperature increases from the ambient temperature to ‎‎250 ̊C, the refractive index changes from n = 2.11 to n = 2.18. Moreover, increasing the ‎temperature, causes the absorption of the layer to increase. The morphology of the films also changes slightly ‎by changing temperature. The average roughness of all three samples is less than half a nanometer.‎.‎‎