title: Ultra-thin ultra-smooth and low-loss silver films on a germanium wetting layer.
abstract: We demonstrate a method to fabricate ultra-thin, ultra-smooth and low-loss silver (Ag) films using a very thin germanium (Ge) layer as a wetting material and a rapid post-annealing treatment. The addition of a Ge wetting layer greatly reduces the surface roughness of Ag films deposited on a glass substrate by electron-beam evaporation. The percolation threshold of Ag films and the minimal thickness of a uniformly continuous Ag film were significantly reduced using a Ge wetting layer in the fabrication. A rapid post-annealing treatment is demonstrated to reduce the loss of the ultra-thin Ag film to the ideal values allowed by the quantum size effect in smaller grains. Using the same wetting method, we have also extended our studies to ultra-smooth silver-silica lamellar composite films with ultra-thin Ag sublayers.
authors.affiliation: Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Chen
authors.forename: Mark D
authors.initials: MD
authors.lastname: Thoreson
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ishii
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Kildishev
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Shalaev