Room-temperature grain growth in sputtered nanoscale Pd thin films: Dynamic scaling behaviour on SiO2

Dynamic scaling behavior has been observed during the room-temperature growth of sputtered Pd films on SiO2 using the scanning electron microscopy technique. By the analyses of the dependence of the Pd grain size and surface density on the film thickness, the dynamical growth exponent z=4.2±0.3 was obtained, suggesting a conservative growth process. The analysis of the fraction of surface covered by Pd as a function of film thickness (up to a maximum of 8.5×1016atoms∕cm2, corresponding to 125nm) allowed us to identify two different growth regimes in the investigated range: films thinner than 1.8×1016atoms∕cm2 (26.5nm) that grow as an outside-cluster system and thicker film that exhibit an islandlike growth.