COMPARATIVE SCANNING PROBE MICROSCOPY STUDY OF THE SURFACE-MORPHOLOGY OF AU FILMS GROWN FROM THE VAPOR ONTO GLASS, FUSED-SILICA, AND MUSCOVITE MICA

In a previous paper [J. A. DeRose, T. Thundat, L. A. Nagahara, and S. M. Lindsay, Surf. Sci. 256, 102 (1991)], the conditions which can be used to grow Au films epitaxially on muscovite mica to obtain large area, flat faces are reported. Since then, it has been reported that Au films grown on an amorphous substrate [J. Hwang and M. A. Dubson, J. Appl. Phys. 72, 1852 (1992)] (nonepitaxy) have shown to be at least as smooth as those on mica. In this article, the results from scanning tunneling microscopy analysis of Au films grown on mica, glass cover slips, and fused silica are compared. By comparing the rms surface roughness (z data standard deviation, SD) values for each film type, we find that the mica films show the smoothest surfaces, i.e., smallest rms surface roughness values. We then attempt to explain these results by taking into account the accepted model of film growth from the vapor (physical vapor deposition) and the surface structure of bare mica, glass (optical microscope slide cover slip), and fused silica as shown with atomic force microscopy.