Effect of 79 MeV Br ion irradiation on the surface features of rutile TiO2 thin film.

In this study, rutile titanium dioxide thin films deposited on Si (100) substrates by DC magnetron sputtering are irradiated by 79 MeV Br ions. Though each Br ion is expected to amorphize the medium along its path, the film remains crystalline even at the highest fluence of irradiation. The evolution of surface of the films with Br ion fluence is studied using atomicforce microscopy. The films were found to smoothen under dense electronic excitation of Br ions. The irregular shape grain of the pristine films convert to circular shape at a fluence of 1 × 1013 Br ions cm-2. Power spectral density (PSD) analysis of the AFM images indicates that irradiation induced smoothing of the surfaces is governed by the surface diffusion process. [ABSTRACT FROM AUTHOR]