Plasmonic materials for metal-insulator-semiconductor-insulator- metal nanoplasmonic waveguides on silicon-on-insulator platform

摘要

The use of various plasmonic metals and insulators in silicon based metal-insulator-semiconductor-insulator-metal (MISIM) nanoplasmonic waveguides are investigated for use in waveguiding applications at 1.55 μm. Sputtered Au, Ag, and Cu as the metal cladding with thermally grown SiO_2 and ALD grown HfO_2 insulating dielectric spacer layers are examined to determine how their fabrication affects the crucial metal-dielectric interface. The experimental propagation lengths and coupling efficiencies to silicon-on-insulator waveguides are compared to theoretical values, with the Au/SiO_2 MISIM nanoplasmonic waveguide showing a propagation length of 7.25 μm. The effect of including an adhesion layer for Au is shown to significantly increase losses.