Surface roughness and in-plane texturing in sputtered thin films

Abstract

Real surfaces are not flat on an atomic scale. Studying the effects of roughness on microstructural evolution is of relevance because films are sputtered onto nonideal surfaces in many applications. To this end, amorphous rough substrates of two different morphologies, either elongated mounds or facets, were fabricated. The microstructural development of films deposited onto these surfaces was examined. In particular, the development of a preferred crystallographic orientation in the plane of growth in 400 nm thick Mo films grown on the rough substrates was studied using scanning electron microscopy, transmission electron diffraction, and high resolution x-ray diffraction ͑using scans in the symmetric grazing incidence x-ray scattering geometry with a synchrotron light source͒. It was found that the degree of texturing was dependent upon the type of roughness and its orientation during deposition. By limiting the average oblique angle of incident adatom flux, rough surfaces slowed the development of in-plane texture. Comparison between experimental data and theoretical predictions showed that a recent analytical model is able to reasonably predict the degree of texturing in films grown onto these surfaces.

Study of the origin of orientation ratio in high-density longitudinal magnetic recording media

“…Reason for this preference of growth in Cr is unclear, though, there were studies on Mo thin films that in-plane texture could happen due to self shadowing, anisotropic grain growth etc. for thicker films [12]. In the present case, we see a preference within the plane at much lower film thicknesses.…”

Perspectives on oblique angle deposition of thin films: From fundamentals to devices

“…The simplest version of OAD on a template uses a rough substrate surface; the elongated mounds or facets promoting the accumulation of deposited material onto the most prominent features, while at the same time preventing the arrival of vapor flux at the shadowed regions [97]. Expanding on this simple approach, the use of substrates with a well-defined lithographic pattern opens up a range of new and unexpected possibilities for the nano-structuring of OAD thin films.…”

Surface roughening and grain orientation dependence of the erosion of polycrystalline stainless steel by hydrogen irradiation

“…The creation of such mirco-relief is investigated for decades (e.g., [4][5][6]) and in recent studies nanostructuring was emphasised (e.g., [16]). Also several theoretical approaches describe this micro-roughening [17,18].…”