Argon gas pressure dependence of the columnar grain structure in iron films deposited obliquely by sputtering

Abstract

The columnar grain structure of iron films obliquely deposited by sputtering at various argon gas pressures (5–20 Pa) was investigated by measuring the optical constants, the magnetic anisotropy and the {110} pole distribution and compared with that of iron films evaporated in argon gas atmospheres (8 × 10 −2−2 Pa). The geometrical incidence angle was 45° and the substrate temperatures T S were 393, 483 and 553 K. The results obtained were as follows. (1) At T s = 393 K with increasing pressure the packing of columnar grains becomes sparse and the bundling of columnar grains disapears. The change in the columnar grain structure is similar to that in evaporated films in spite of the different pressure range. (2) With increasing T S the change in the columnar grain structure with pressure becomes small and the similarity between sputtered and evaporated films diminishes. Replica electron microscopy provided visual evidence of these results.