Ultra-thin ultra-smooth and low-loss silver films on a germanium wetting layer

作者：Chen Weiqiang^*; Thoreson Mark D; Ishii Satoshi; Kildishev Alexander V; Shalaev Vladimir M

来源：Optics Express, 2010, 18(5): 5124-5134.

DOI：10.1364/OE.18.005124

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.

• 出版日期2010-3-1