STM study of fractal scaling in evaporated gold films

Fractal characterization of vacuum-evaporated gold films on glass substrates with thicknesses (h) comprised between 30 and 850 nm is made from STM data by using the dynamic scaling approach for surface growth. The rms roughness (ξ) and the scan length (L) obey a ξ versus Lα relationship with α depending on h. For h ⪰ 500 nm and L >ds, the averag e column diameter, α≌13 in agreement with the predictions of ballistic deposition models without restructing. For L s, α ≌ 0.9 approaching a euclidean value. The STM method is verified through its application to several computer-generated surfaces, leading to a good agreement with the theoretical values.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada