Scalable methods for ultra-smooth platinum in nanoscale devices

Abstract

Ultra-smooth metal structures are increasingly important in nanoscale device applications, from photonics to molecular electronics and 2D material growth. We describe three methods for achieving ultra-smooth platinum: patterned template stripping, chemical mechanical polishing and giant grain growth. Specifically, we demonstrate 1) the first use of spin-on glass as an adhesive for the transfer of a patterned platinum film via template stripping, enabling the film to be exposed to harsher solvents and at higher temperatures; 2) an updated CMP process for platinum with slurry materials that are currently available; 3) a giant grain growth process on a 4″ quartz substrate that uses a thinner Pt film than previously reported. Overall, root mean squared film roughness was decreased from ~14 Å for as-deposited platinum to <4 Å, while improving on scalability and compatibility subsequent processing of pre-existing techniques. Keywords: Nanofabrication, Nanotechnology, Molecular electronics, Planarization, Template stripping, Chemical mechanical polishing, Abnormal grain growth