Silver-based transparent conductive layers interfaced with copper traces and methods for forming the structures

Abstract

A method is described for method for patterning a metal layer interfaced with a transparent conductive film, in which the method comprises contacting a structure through a patterned mask with an etching solution comprising Fe+3 ions, wherein the structure comprises the metal layer comprising copper, nickel, aluminum or alloys thereof covering at least partially a transparent conductive film with conductive elements comprising silver, to expose a portion of the transparent conductive film. Etching solutions and the etched structures are also described.

What is claimed is: 
     
         1 . A method for patterning a metal layer interfaced with a transparent conductive film, the method comprising:
 contacting a structure through a patterned mask with an etching solution comprising Fe +3  ions, wherein the the structure comprises the metal layer comprising copper, nickel, aluminum or alloys thereof covering at least partially a transparent conductive film with conductive elements comprising silver, to expose a portion of the transparent conductive film.   
     
     
         2 . The method of  claim 1  wherein the etching solution comprises water and from about 0.001M to about 0.25M Fe +3 . 
     
     
         3 . The method of  claim 2  wherein the etching solution further comprises a strong acid at a concentration from about 0.0001M to about 0.1M. 
     
     
         4 . The method of  claim 2  wherein the etching solution further comprises from 0.001 to about 0.5 wt % non-ionic surfactant. 
     
     
         5 . The method of  claim 2  wherein the etching solution further comprises from 0.001M to about 0.25M Fe +2 . 
     
     
         6 . The method of  claim 1  wherein the etching solution has from about 0.005M to about 0.05M Fe +3 , from about 0.0025 wt % to about 0.1 wt % non-ionic surfactant, and the strong acid at a concentration from about 0.00025M to about 0.03M, wherein the strong acid is nitric acid and the anions balancing the iron cations are nitrate anions. 
     
     
         7 . The method of  claim 1  wherein the transparent conductive film comprises a fused metal nanostructured network with a polymer overcoat having an average thickness from about 25 nm to about 500 nm. 
     
     
         8 . The method of  claim 1  wherein the contacting comprises immersion of the structure in the etching solution for a selected period of time, and the method further comprising rising the structure following completion of the immersion. 
     
     
         9 . The method of  claim 1  wherein the contacting comprises depositing the etching solution over the patterned mask, and the method further comprising depositing a rinse solution over the patterned mask at the completion of the etching process. 
     
     
         10 . The method of  claim 1  wherein the patterned mask comprises photoresist and the pattern is formed using photolithography. 
     
     
         11 . The method of  claim 1  further comprising patterning the transparent conductive film after etching the metal layer. 
     
     
         12 . The method of  claim 11  wherein the patterning of the conductive film is performed using TCTF. 
     
     
         13 . The method of  claim 1  wherein the metal layer comprises a layer of copper covered with a layer of nickel or aluminum. 
     
     
         14 . The method of  claim 1  wherein following patterning the structure comprises a polymer substrate, a transparent conductive film covering at least part of a surface of the polymer substrate and metal traces confined to at least a portion of a bezel region along a border of the surface, wherein elements of the transparent conductive film are in electrical contact with portion of the metal trace to form a conduction pathway through the transparent conductive film, wherein the transparent conductive film has a sheet resistance of no more than 95 ohms/sq. 
     
     
         15 . A patterned film comprising a polymer substrate, a transparent conductive film covering at least part of a surface of the polymer substrate and metal traces confined to at least a portion of a bezel region along a border of the surface, wherein elements of the transparent conductive film are in electrical contact with portion of the metal trace to form a conduction pathway through the transparent conductive film, wherein the transparent conductive film has a sheet resistance of no more than 95 ohms/sq, and wherein the metal traces have a configuration of an etched material. 
     
     
         16 . The patterned film of  claim 15  wherein the metal traces comprise a layer of copper having a thickness from about 100 nm to about 1 micron and wherein the top surfaces of the copper traces have a layer of nickel, aluminum or an alloy thereof. 
     
     
         17 . The patterned film of  claim 15  wherein the copper traces have features with a resolution of no more than about 5 microns. 
     
     
         18 . An etching solution consisting essentially of water, from about 0.001M to about 0.25M Fe +3 , strong acid at a concentration from about 0.0001M to about 0.1M, optionally from 0.001 wt % to about 0.5 wt % surfactant, and optionally from 0 to about 0.25M Fe +2 , along with selected anions for charge balance of the listed cations. 
     
     
         19 . The etching solution of  claim 18  wherein the strong acid is nitric acid and the anions balancing the iron cations comprise nitrate anions. 
     
     
         20 . The etching solution of  claim 18  having from about 0.0025 wt % to about 0.1 wt % non-ionic surfactant. 
     
     
         21 . The etching solution of  claim 18  having from about 0.005M to about 0.05M Fe +3 . 
     
     
         22 . The etching solution of  claim 18  having from about 0.005M to about 0.05M Fe +3 , from about 0.0025 wt % to about 0.1 wt % non-ionic surfactant, and the strong acid at a concentration from about 0.00025M to about 0.03M, wherein the strong acid is nitric acid and the anions balancing the iron cations are nitrate anions.