The effect of Ti and ITO adhesion layers on gold split-ring resonators

Ultrathin adhesion layers serve a well-documented fabrication purpose while its influence on the optical properties of gold nanostructures is often neglected. Gold split-ring resonators are fabricated with two commonly used adhesion layers: titanium and indium tin oxide. When compared to all-gold reference samples, a spectral shift of the ground mode resonance is observed. For the titanium sample the spectral shift is accompanied by a resonance broadening, which is less profound for indium tin oxide. The mutual correlation between the shift and the broadening is shown to be qualitatively consistent with perturbative considerations. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3532096]