COLUMNAR STRUCTURE OF OBLIQUELY DEPOSITED COBALT FILMS PREPARED AT LOW SUBSTRATE TEMPERATURES

The columnar grain structure of obliquely deposited cobalt films prepared at low substrate temperatures (213 and 273 K) was investigated. The incidence angle was 60° and the pressure during deposition was 4.0×10-3 Pa. In films prepared at 213 K the direction of the column axis and the bundling of columns strongly depend on the vapour beam density. At high densities the column axis deviates from the beam direction towards the film normal and a well-defined bundle along the direction perpendicular to the incidence plane is formed. At low densities the column axis is close to the beam direction and no bundle is formed. In films prepared at 273 K, on the contrary, the change in the deviation of column axis with beam density is small and bundle formation is scarcely observed, irrespective of beam density. On the basis of these results the movement of adatoms due to their momenta is discussed. © 1990.