Alignment of thin films by glancing angle ion bombardment during deposition

Abstract

Glancing angle ion bombardment during thin-film deposition is shown to have a pronounced alignment effect on crystallographic orientation. Restricted fiber texture is achieved in Nb films deposited at room temperature onto amorphous silica substrates by Ar ion beam sputtering, with simultaneous bombardment by 200 eV Ar+ ions at 20° from glancing angle. The alignment direction corresponds to a channeling direction for the incident ions between (110) planes, for which a low sputtering yield is expected. The degree of alignment is measured as a function of ion/atom arrival rate ratio up to 1.3 Ar+ ions per Nb film atom, and is shown to increase monotonically with the fraction resputtered.