Ultrasmooth ultrathin Ag films by AlN seeding and Ar/N2 sputtering for transparent conductive and heating applications

Abstract

We report on the fabrication of 15-nm Ag films with 0.6 nm RMS roughness and only 3 times the bulk electrical resistivity using a transparent AlN seed layer and Ar/N2 (60% N2) based sputtering of Ag. Either AlN-seeding or Ar/N2 sputtering alone reduces the percolation threshold of Ag thin films and smoothens their surface. However, significant reduction in localized surface plasmon resonance was observed only through the use of Ar/N2 sputtering. As a demonstration of its application as a transparent conductive film, we construct a transparent heat-regulating metallo-dielectric coating using our ultrathin ultrasmooth Ag films with minimal optical absorption loss.