Characterization of nanolaminate thickness using multi-parametric surface plasmon resonance

Abstract

Nanolaminates play a significant role in the precision optical components, and protective barrier coatings. We present a new non-destructive method for characterization of nanolaminates in terms of thickness and refractive index based on Multi-Parametric Surface Plasmon Resonance (MP-SPR). In this paper, we briefly compare novel MP-SPR technology and traditional ellipsometry approach and then show MP-SPR on three examples that would be difficult-to-measure with ellipsometry. In the first case, MP-SPR is used to measure thickness of Langmuir-Blodgett multilayer film of Cr-Au-SACd, where each SACd layer can be measured individually without averaging. In the second case, vacuum deposited Cr-Au-TaC (tetragonal amorphous carbon) is measured. In the third case, alternating nanolayers of Al2O3-Pt deposited by Atomic Layer Deposition are measured. This shows that Multi-Parametric Surface Plasmon Resonance (MP-SPR) overcomes drawbacks of traditional optical methods and enables measurements of metal (light absorbing) nanolaminates and of ultrathin nanolayers.