Optical constants and roughness study of dc magnetron sputtered iridium films

Authors

Li Yan, University of Nebraska-Lincoln
John A. Woollam, University of Nebraska-LincolnFollow

Date of this Version

10-15-2002

Comments

Published in JOURNAL OF APPLIED PHYSICS VOLUME 92, NUMBER 8, 15 OCTOBER 2002. © 2002 American Institute of Physics. Used by permission.

Abstract

Extremely smooth thin films of iridium have been deposited onto superpolished fused silica substrates using dc magnetron sputtering in an argon plasma. The influence of deposition process parameters on film microroughness has been investigated. In addition, film optical constants have been determined using variable angle spectroscopic ellipsometry, over the spectral range from vacuum ultraviolet to middle infrared (140 nm–35 μm). Because the Ir films were optically thick and the surface roughnesses were measured by atomic force microscopy then accounted for in the optical model, the as-determined film optical constants are expected to be the best available for Ir bulk metals, minimally affected by surface overlayers or microstructure.