Titanium Nitride Plasmonic Nanohole Arrays for CMOS-Compatible Integrated Refractive Index Sensing: Influence of Layer Thickness on Optical Properties

Abstract The combination of nanohole arrays with photodetectors can be a strategy for the large-scale fabrication miniaturized and cost-effective refractive index sensors on Si platform. However, complementary metal–oxide–semiconductor (CMOS) processes place restrictions in particular material that used structures. Here, we focus using CMOS compatible transition metal nitride Titanium Nitride (TiN) (NHAs). We investigate optical properties TiN NHAs different thicknesses (50 nm, 100 150 nm) fabricated high-precision industrial possible applications integrated, plasmonic sensors. Reflectance measurements show pronounced Fano-shaped resonances, resonance wavelengths between 950 1200 attributed to extraordinary transmission (EOT) through NHAs. Using measured permittivity as an input, spectra are reproduced by simulations large degree accuracy: Simulated deviate less than 10 average deviation 4 nm observed at incidence angles 30° 40°. Our experimental results demonstrate increase thickness layer from 50 leads sensitivity 614.5 nm/RIU 765.4 nm/RIU, which attribute stronger coupling individual LSPRs hole edges spatially extended SPPs. performance on-chip