Nanometer patterning of thin CoSi 2-films by application of local stress

Abstract

We have developed a self-assembly method for patterning thin CoSi 2 layers on Si(100) during their formation in a solid state reaction. This technique is based on anisotropic diffusion in a local stress field during rapid thermal processing. The stress is induced by a layer structure consisting of 30 nm SiO 2 and 300 nm Si 3N 4 which is patterned with conventional optical lithography. We have investigated two different silicide formation processes. Firstly, we deposited Co on Si in a UHV MBE chamber. Rapid thermal annealing leads to the formation of polycrystalline CoSi 2. Secondly, we used a titanium oxide mediated epitaxy process. For both processes we observed nanostructures with dimensions of about 100 nm showing wave-like separation edges in the first case and good uniformity in the second case.