Complimentary Metal-Oxide-Semiconductor compatible deposition of nanoscale transition-metal nitride thin films for plasmonic applications

Transition metal nitrides have received significant interest for use within plasmonic and optoelectronic devices due to their tunability and environmental stability. However, deposition temperature remains a significant barrier to widespread adoption through the integration of transition metal nitrides as plasmonic materials within CMOS fabrication processes. Binary, ternary and layered plasmonic transition metal nitride thin films based on titanium and niobium nitride are deposited using High Power Impulse Magnetron Sputtering (HIPIMS) technology. The increased plasma densities achieved in the HIPIMS process allow thin films with high plasmonic quality to be deposited at CMOS compatible temperatures of less than 300°C. Thin films are deposited on a range of industrially relevant substrates and display tunable plasma frequencies in the ultraviolet to visible spectral ranges. Strain mediated tunability is discovered in layered films compared to ternary films. The thin film quality, combined with the scalability of the deposition process, indicates that HIPIMS deposition of nitride films is an industrially viable technique and can pave the way towards the fabrication of next-generation plasmonic and optoelectronic devices.