COLUMNAR GRAIN-STRUCTURE OF IRON FILMS DEPOSITED OBLIQUELY BY SPUTTERING

The substrate temperature dependence of columnar grain structure was investigated in iron films deposited obliquely by rf sputtering. The geometrical incidence angle was 45° and the substrate temperature Ts ranged from 337 to 672 K. In all the films the column axis deviates from the beam direction towards the film normal. With increasing Ts the deviation angle αD of the column axis from the beam direction increases up to 45°. Above Ts = 460 K, αD = 45°, the column axis is perpendicular to the film plane. Only in the Ts range 460-530 K do columnar grains align along the direction perpendicular to the incidence plane and form a bundle. Comparing these results with those of evaporated films the formation mechanism of the columnar grain structure in sputtered films is discussed. © 1990.