INFLUENCE OF ELECTRON SCATTERING FROM MORPHOLOGICAL GRANULARITY AND SURFACE ROUGHNESS ON THIN FILM ELECTRICAL RESISTIVITY

We report electrical resistivity measurements of platinum and gold thin films over a range of film thickness d (1.3 ≤ d ≤ 11.7nm), together with associated measurements of the film morphological and crystallographic grain size. The resistivity results are compared to predictions of the Fuchs–Sondheimer and the Mayadas–Shatzkes models, based on the electron mean free path and crystallographic grain size, and the agreement is not satisfactory. We describe an alternative model based on elastic electron scattering with morphological granularity (grain structure as measured on the film surface) and film surface roughness, and good agreement is obtained with the experimental results. This suggests that electron scattering by morphological granularity and surface roughness plays an important role in determining the electrical resistivity of thin metal films.