The influence of ion bombardment intensity during deposition on nickel films microstructure

Abstract

Nickel films were deposited from a vapour phase (e-gun source) onto amorphous glass substrates at room temperature during a simultaneous bombardment with nitrogen ions at low pressure (4 x 10(-2) Pa). Under a constant partial pressure of nitrogen and negative substrate bias voltages the effect of bombardment intensity on the texture and morphology of Ni films (about 1 mu m) has been investigated by XRD and STM methods. The films under investigation exhibit a Variable degree of (200) preferred orientation by changing the ion to atom flux ratio (IAR) from 0.03 to 0.3. It was found that complete (200) texture was achieved for an IAR of about 0.1 and that further increase of IAR induces the decrease of preferred orientation. X-ray diffraction in combination with profiling by a 1 keV argon ion beam bombardment has been used for in depth texture and grain size analysis. It has been shown that oriented growth, grain size and morphology correlate with changes of bombardment intensity during the deposition as well as with the substrate bias potential. (C) 1999 Elsevier Science S.A. All rights reserved.