Texture and columnar structure of evaporated cobalt films: I

Abstract

The geometric and crystallographic structures of crystallites in cobalt films about 6000 Å in thickness have been investigated. Films were evaporated at an angle of incidence of 70° and an evaporation rate of 1700 Å min -1. The temperature T s of the glass substrate was varied from 100 to 450°C. The crystallographic structure was analysed by plotting pole figures obtained using the Schulz X-ray method, and the geometric structure was observed by replica electron microscopy of the surfaces and of cross sections of the films. The results obtained can be summarized as follows. (1) There was a critical substrate temperature T sc of about 200–250°C, below which the texture was in the final orientation and above which it was in the initial orientation. (2) The development of columnar grains was clearly seen in films evaporated below T sc but this did not occur directly on the substrate in the case of evaporation near T sc. Above T sc, the observation of the columns became difficult and no grains were recognizable as T s was increased.