Aperture masks for circuit fabrication

Abstract

Aperture masks and deposition techniques for using aperture masks are described. In addition, techniques for creating aperture masks and other techniques for using the aperture masks are described. The various techniques can be particularly useful in creating circuit elements for electronic displays and low-cost integrated circuits such as radio frequency identification (RFID) circuits. In addition, the techniques can be advantageous in the fabrication of integrated circuits incorporating organic semiconductors, which typically are not compatible with wet processes.

1 . A polymeric aperture mask, the polymeric aperture mask comprising: 
 a polymer, and    a magnetic material.    
     
     
         2 . The polymeric aperture mask of  claim 1 , wherein the magnetic material is impregnated into the polymer.  
     
     
         3 . The polymeric aperture mask of  claim 1 , wherein the magnetic material is coated on the polymer.  
     
     
         4 . The polymeric aperture mask of  claim 1 , wherein the magnetic material is laminated to the polymer.  
     
     
         5 . A method comprising: 
 positioning a flexible repositionable polymeric aperture mask in proximity to a deposition substrate;    controlling sag in the flexible aperture mask; and    depositing material through the flexible aperture mask to form a layer on the deposition substrate that defines at least a portion of an integrated circuit.    
     
     
         6 . The method of  claim 5 , wherein the flexible aperture mask includes a pressure sensitive adhesive on one side, wherein controlling sag comprises adhering the flexible aperture mask to the deposition substrate via the pressure sensitive adhesive.  
     
     
         7 . The method of  claim 5 , wherein controlling sag comprises stretching the flexible aperture mask.  
     
     
         8 . A method comprising: 
 ablating a polymeric film formed with a material layer on a first side of the polymeric film from a side opposite the material layer to define a pattern in the polymeric film, wherein the pattern defines deposition apertures that extend through the polymeric film; and    removing the material to form a polymeric aperture mask.    
     
     
         9 . The method of  claim 8 , wherein ablating the polymeric film comprises ablating a polyimide film.  
     
     
         10 . The method of  claim 8 , wherein the material layer comprises a metal layer.  
     
     
         11 . The method of  claim 10 , wherein the metal layer comprises a copper layer.  
     
     
         12 . The method of  claim 10 , wherein removing the material layer comprises etching the metal layer from the polymeric film.  
     
     
         13 . A method comprising: 
 forming a repositionable polymeric aperture mask;    using the polymeric aperture mask as a pattern in an etching process to etch at least one layer of a thin film transistor.    
     
     
         14 . The method of  claim 13 , further comprising reusing the polymeric aperture mask as a pattern in another etching process.  
     
     
         15 . A repositionable polymeric aperture mask comprising a pattern of deposition apertures that define at least a portion of an integrated circuit, wherein the pattern has a dimension greater than a centimeter, wherein at least one deposition aperture has a width less than approximately 1000 microns and wherein the portion of the integrated circuit comprises at least a portion of a thin film transistor.  
     
     
         16 . A repositionable polymeric aperture mask comprising: 
 a polyimide; and    a pattern of deposition apertures, wherein the pattern has a dimension greater than a centimeter, and wherein at least one deposition aperture has a width less than approximately 1000 microns.    
     
     
         17 . A method comprising: 
 ablating a pattern in a polymeric film to create a repositionable polymeric aperture mask, wherein the pattern defines at least one deposition aperture that corresponds to an element of an integrated circuit.    
     
     
         18 . The method of  claim 17 , further comprising depositing material on a deposition substrate through the polymeric aperture mask to define a patterned layer of an integrated circuit.  
     
     
         19 . The method of  claim 17 , wherein ablating comprises laser ablating.  
     
     
         20 . The method of  claim 19 , further comprising controlling the laser ablation to create an acceptable wall-angle of one or more of the deposition apertures.