Characterization of thermally stable Ir–Ta alloy thin films deposited by sputtering

Abstract

Ir–Ta alloy thin films were deposited on SiO 2/Si substrates by a magnetron sputtering system using pure Ar as sputtering gas. The Ir/Ta composition ratio of the alloy films was varied by changing the number of Ta chips on an Ir target. The crystal structure of the alloy films changed from fcc-Ir to Ir 3Ta, α-(Ir,Ta), Ta 3Ir, and bcc-Ta with increasing Ta content. Post-deposition annealing of the alloy films was carried out in oxygen at temperatures from 300°C to 800°C for 1 h. The alloy films with Ta contents of 10–50 at% indicated low electrical resistivities below 220 μΩ cm and the low resistivities remained after annealing up to 600°C.