Fabrication of Wire Grid Polarized Film with Trench Fill Silver Electrodeposition

Abstract

Wire-grid polarizing films have been used intensively as parts of the displays of liquid crystal TVs, liquid crystal projectors, and personal computers. Wire-grid polarizing films have metal wires and whose width is less than the wave length of light. The incident light having perpendicular polarization to the wire pass through the wire-grid polarizing films and the light of parallel polarization reflects, Since silver has the highest reflectance in metal, the efficiency of recycle use of reflected light on the Ag-WGPOLARIZER is expected to be the highest among other metals.
With a cyanide-free bath, we damascene electrodeposited silver into trenches 145 nm wide and 175 nm deep. The silver deposited on the film was then partly removed using ion milling and metal wires were fabricated. The reflectance of S-polarization is inversely related to the amount of voids in the trenches. Smaller current density and a larger amount of Na₂S₂O₃ decrease the amount of voids and hence increase the reflectance of S-polarization.