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

Weiqiang Chen, Purdue University - Main Campus
Mark D. Thoreson, Purdue University - Main Campus
Satoshi Ishii, Purdue University - Main Campus
Alexander V. Kildishev, Birck Nanotechnology Center, School of ECE
V. M. Shalaev, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University

Date of this Version



ISSN: 1094-4087

This document has been peer-reviewed.



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. (C) 2010 Optical Society of America


Engineering | Nanoscience and Nanotechnology