Preparation and characterization of magnetron sputtered, ultra-thin Cr0.63Mo0.37 films on MgO

Abstract

We report on the preparation of lattice matched heteroepitaxial films in a dc magnetron sputtering discharge. CrxMo1−x thin films were grown on MgO(1 0 0) substrate, choosing the composition of the binary metal alloy to be x=0.63, so that the film is lattice matched to the substrate when the 〈100〉 orientation of the film is parallel to the 〈110〉 orientation of the substrate. Ex situ x-ray diffraction and low angle x-ray reflectivity measurements were performed to determine the film structure, film thickness, as well as the surface and interface roughness. We determine the optimum growth temperature to be 200 °C. Using this temperature 0.4–15 nm thick films were prepared. The resistivity of the films was measured ex situ using a four-point-probe. The resistivity dropped rapidly with increasing thickness. The resistivity versus thickness data was found to be well described with Namba’s model, which includes film roughness as a parameter.