Morphological evolution of pulsed laser deposited ZrO2 thin films

Abstract

Morphological evolution of ZrO2 thin films deposited during pulsed laser deposition of Zr in O2 atmosphere has been experimentally studied at two different film deposition temperatures, 300 and 873 K. The roughness exponent, α, the growth exponent, β, the coarsening exponent, 1/z, and the exponent defining the evolution of the characteristic wavelength of the surface, p, for depositions at 300 K amounted to β=1.0±0.1, α=0.4±0.1, 1/z=0.34±0.03, and p=0.49±0.03, whereas for depositions carried out at 873 K amounted to β=0.3±0.3, α=0.4±0.2, and 1/z=0.0±0.2. Experimental error becomes important due to the flat morphology of the films inherent to the deposition technique. The change in the surface topography with the film temperature has been studied with the help of a simple Monte Carlo model which indicates the existence of two different growth regimes: a shadowing dominated growth, occurring at low temperatures, characterized by calculated values β=1.00±0.04, α=0.50±0.04, p=0.46±0.01, and 1/z=0.35±0.02 and a diffusion dominated growth that takes place at high temperatures as well as at low deposition rates, characterized by calculated values β=0.15±0.08, α=0.33±0.04, and 1/z=0.33±0.07. The good agreement obtained between the experimental and simulated parameters is discussed within the frame of the general characteristics of the deposition method.