Columnar grain structure in cobalt films deposited obliquely by introducing oxygen during sputtering

In order to clarify the effect of oxidization on the columnar grains aligned parallel to the incidence plane, which is peculiar to the sputtered films, sputtered cobalt films were prepared by introducing oxygen. Partial pressure of O-2 gas ranged from 0 to 0.6 Pa and total pressure of Ar and O-2 gasses during deposition was 20 Pa. The incidence angle was 45degrees and the substrate temperatures were 332 and 492K. At 332K with oxidizing the degree of the parallel alignment of columnar grains decreases and the {10 (1) over bar1} pole distribution becomes broad gradually. This result is consistent with our model for the formation mechanism of the parallel alignment of columnar grains. At 492 K with oxidizing the parallel alignment and the crystallographic preferred orientation disappear. However the magnetic anisotropy, which is considered to be caused by them, increases monotonically. The cause of this increase has been unclear so far. (C) 2002 Elsevier Science B.V. All rights reserved.