Surface roughness of sputter-deposited gold films: a combined X-ray technique and AFM study

Citation
C. Schug et al., Surface roughness of sputter-deposited gold films: a combined X-ray technique and AFM study, SURF INT AN, 27(7), 1999, pp. 670-677
Citations number
23
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
SURFACE AND INTERFACE ANALYSIS
ISSN journal
01422421 → ACNP
Volume
27
Issue
7
Year of publication
1999
Pages
670 - 677
Database
ISI
SICI code
0142-2421(199907)27:7<670:SROSGF>2.0.ZU;2-W
Abstract
We applied grazing incidence x-ray specular and non-specular reflectivity ( GIXR) and small-angle x-ray scattering (SAXS) to study the surface roughnes s of gold films on quartz glass substrates. Two model systems were prepared : one series of Au films was sputtered in Ar at 3 x 10(-3)mbar (Au1 films) and one in residual air at 3 x 10(-1) mbar (Au2). The combined x-ray experi ments showed that the Aul films are compact and smooth, with-mean-square (r ms) roughness values too low to be quantified by means of atomic force micr oscopy (AFM) or SAXS. The surfaces of film and substrate exhibit a strong c ross correlation that is gradually lost with increasing film thickness. The surface height-height correlation functions are well described by a self-a ffine model. In contrast, as directly proved via AFM, the Au2 films consist of islands that are coarsening with increasing film thickness. The film su rface showed no cross-correlation with the substrate surface at all. The SA XS curves from the Au2 films were attributed to a volume scattering effect, by interpreting the films in terms of a two-dimensional array of hard hemi spheres. Copyright (C) 1999 John Wiley & Sons, Ltd.