Method of Making a Microelectronic and/or Optoelectronic Circuitry Sheet

Abstract

A circuitry sheet comprising an electronic device layer stack containing electronic devices, e.g., thin-film transistors, or portions thereof, formed by removing material from both sides of the device layer stack. The circuitry sheet may be made by an electronic/optoelectronic device manufacturing method that includes the steps of forming the device layer stack on a temporary substrate removing material from both sides of the device layer stack, and then attaching a permanent substrate to the device layer stack. The method uses one or more resist layers that may be activated simultaneously and independently to impart distinct circuit pattern images into each of a plurality of image levels within each resist layer, thereby obviating repetitive sequential exposure, registration and alignment steps.

1 . A method of defining at least one defined feature in a substrate, comprising: 
 a) providing a substrate;    b) applying a first lower photoresist layer on said substrate;    c) applying a first upper photoresist layer on said first lower photoresist layer so as to form a first photoresist stack;    d) exposing said first upper photoresist layer through a first mask;    e) exposing said first lower photoresist layer through a second mask and through said first upper photoresist layer simultaneously with said exposing of said first upper photoresist layer with said first mask so as to impart a first image of at least one first structure into said first photoresist stack;    f) developing said first upper photoresist layer and said first lower photoresist layer so that openings form in each of said first upper photoresist layer and said first lower photoresist layer to define said at least one first structure in said first photoresist stack; and    g) performing an etch to transfer said at least one first structure formed in said first photoresist stack into said substrate so as to form a first defined feature in said substrate.    
     
     
         2 . A method according to  claim 1 , wherein step a) includes providing a substrate having a device coatings stack and step b) includes applying said first lower photoresist layer over said device coatings stack.  
     
     
         3 . A method according to  claim 1 , wherein said first mask has a first pattern and step e) includes exposing said first lower photoresist layer through a second mask having a second pattern differing from said first pattern.  
     
     
         4 . A method according to  claim 1 , wherein step b) includes applying a first lower photoresist layer that is responsive to light of a first wavelength and step c) includes applying a first upper photoresist layer that is responsive to light of a second wavelength differing from said first wavelength.  
     
     
         5 . A method according to  claim 4 , wherein said first lower photoresist layer is substantially unresponsive to said light of said second wavelength.  
     
     
         6 . A method according to  claim 4 , wherein said first upper photoresist layer is substantially unresponsive to said light of said first wavelength.  
     
     
         7 . A method according to  claim 1 , wherein step b) includes applying a first lower photoresist layer that is responsive to light of a first wavelength and step c) includes applying a first upper photoresist layer that is also responsive to said light of said first wavelength.  
     
     
         8 . A method according to  claim 1 , wherein said substrate has a first side and a second side spaced from said first surface, and the method further comprises: 
 performing steps b) through f) relative to said first side of said substrate;    applying a second photoresist layer on said second side of said substrate;    exposing said second photoresist layer through at least one mask so as to define in said second photoresist layer at least one second structure;    developing said second photoresist layer so that openings form in said second photoresist layer to define said at least one second structure in said second photoresist layer; and    performing an etch to transfer said at least one second structure formed in said second photoresist layer into said substrate so as to form a second defined feature in said substrate.    
     
     
         9 . A method according to  claim 8 , wherein the step of exposing said second photoresist layer through said at least one mask is performed simultaneously with step d).  
     
     
         10 . A method according to  claim 9 , further comprising performing in a roll-to-roll process steps a) through f) and the step of exposing said second photoresist layer.  
     
     
         11 . A method according to  claim 10 , further comprising performing steps a) through f) and the step of exposing said second photoresist layer in forming at least parts of a plurality of corresponding respective thin film transistors.  
     
     
         12 . A method according to  claim 9 , wherein step a) includes forming a device layer stack on a temporary substrate.  
     
     
         13 . A method according to  claim 9 , further comprising, prior to each of step b) and the step of exposing said second photoresist layer, removing said temporary substrate.  
     
     
         14 . A method according to  claim 8 , wherein the step of applying said second photoresist layer comprises: 
 applying a second lower photoresist layer on said second side of said substrate; and    applying a second upper photoresist layer on said second lower photoresist layer so as to form a second photoresist stack; and    the step of exposing said second photoresist layer through at least one mask comprises: 
 exposing said second upper photoresist layer through a third mask; and  
 exposing said second lower photoresist layer through a fourth mask and through said second upper photoresist layer simultaneously with said exposing of said second upper photoresist layer with said third mask so as to impart a second image of at least one second structure into said second photoresist stack.  
   
     
     
         15 . A method according to  claim 14 , wherein said first mask has a first pattern, said third mask has a third pattern and step e) includes exposing said first lower photoresist layer through a second mask having a second pattern differing from said first pattern and the step of exposing said second lower photoresist layer includes exposing said second lower photoresist layer through a fourth mask having a fourth pattern differing from said third pattern.  
     
     
         16 . A method according to  claim 14 , wherein steps d) and e) include exposing said first upper photoresist layer and said first lower photoresist layer with corresponding respective differing wavelengths of light.  
     
     
         17 . A method according to  claim 14 , wherein the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with corresponding respective different wavelengths of light.  
     
     
         18 . A method according to  claim 14 , wherein the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with the same wavelength of light.  
     
     
         19 . A method according to  claim 14 , wherein steps d) and e) include exposing said first upper photoresist layer and said first lower photoresist layer with the same wavelength of light and the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with the same wavelength of light.  
     
     
         20 . A method according to  claim 14 , wherein steps d) and e) include exposing said first upper photoresist layer and said first lower photoresist layer with differing wavelengths of light and the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with differing wavelengths of light.  
     
     
         21 . A method of defining at least one defined feature in a substrate, comprising: 
 a) providing a substrate;    b) applying a first unitary photoresist layer on said substrate;    c) exposing said first unitary photoresist layer through a first mask;    d) exposing said first unitary photoresist layer through a second mask simultaneously with said exposing of said first unitary photoresist layer with said first mask so as to impart an image of at least one first structure into said first unitary photoresist layer;    e) developing said first unitary photoresist layer to define said at least one first structure; and    f) performing an etch to transfer said at least one first structure formed in said first unitary photoresist layer into said substrate so as to form a first defined feature in said substrate.    
     
     
         22 . A method according to  claim 21 , wherein step a) includes providing a substrate having a device coatings stack and step b) includes applying said first unitary photoresist layer over said device coatings stack.  
     
     
         23 . A method according to  claim 21 , wherein said first mask has a first pattern and step d) includes exposing said first photoresist layer through a second mask having a second pattern differing from said first pattern.  
     
     
         24 . A method according to  claim 21 , further including performing steps c) and d) using the same wavelength of light.  
     
     
         25 . A method according to  claim 21 , further including performing step c) using a first wavelength of light and step d) using a second wavelength of light different from said first wavelength.  
     
     
         26 . A method according to  claim 21 , wherein said substrate has a first side and a second side spaced from said first surface, and the method further comprises: 
 performing steps b) through f) relative to said first side of said substrate;    applying a second photoresist layer on said second side of said substrate;    exposing said second photoresist layer through at least one mask so as to define in said second photoresist layer at least one second structure;    developing said second photoresist layer to define said at least one second structure; and    performing an etch to transfer said at least one second structure formed in said second photoresist layer into said substrate so as to form a second defined feature in said substrate.    
     
     
         27 . A method according to  claim 26 , wherein the step of exposing said second photoresist layer through said at least one mask is performed simultaneously with step d).  
     
     
         28 . A method according to  claim 27 , further comprising performing in a roll-to-roll process steps a) through f) and the step of exposing said second upper photoresist layer.  
     
     
         29 . A method according to  claim 28 , further comprising performing steps a) through f) and the step of exposing said second photoresist layer in forming at least parts of a plurality of corresponding respective thin film transistors.  
     
     
         30 . A method according to  claim 26 , wherein step a) includes forming a device layer stack on a temporary substrate.  
     
     
         31 . A method according to  claim 30 , further comprising, prior to step b) and the step of exposing said second photoresist layer, removing said temporary substrate.  
     
     
         32 . A method according to  claim 26 , wherein the step of exposing said second photoresist layer through at least one mask comprises: 
 exposing said second photoresist layer through a third mask; and    exposing said second photoresist layer through a fourth mask simultaneously with said exposing of said second photoresist layer with said third mask so as to impart an image of at least one second structure into said first unitary photoresist layer.    
     
     
         33 . A method according to  claim 26 , wherein the step of applying said second photoresist layer comprises: 
 applying a second lower photoresist layer on said second side of said substrate; and    applying a second upper photoresist layer on said second lower photoresist layer so as to form a second photoresist stack; and    the step of exposing said second photoresist layer through at least one mask comprises:    exposing said second upper photoresist layer through a third mask; and    exposing said second lower photoresist layer through a fourth mask and through said second upper photoresist layer simultaneously with said exposing of said second upper photoresist layer with said third mask so as to impart a second image of at least one second structure into said second photoresist stack.    
     
     
         34 . A method according to  claim 33 , wherein the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with corresponding respective different wavelengths of light.  
     
     
         35 . A method according to  claim 33 , wherein the steps of exposing each of said second upper photoresist layer and said second lower photoresist layer include exposing said second upper photoresist layer and said second lower photoresist layer with the same wavelength of light.  
     
     
         36 . A method according to  claim 33 , wherein the step of exposing said second photoresist layer is performed simultaneously with step d).  
     
     
         37 . A method according to  claim 33 , wherein step d) and the step of exposing said second photoresist layer together include exposing said first unitary photoresist layer and said second photoresist layer with corresponding respective differing wavelengths of light.  
     
     
         38 . A method according to  claim 33 , wherein each of step d) and the step of exposing said second photoresist layer includes exposing said first unitary photoresist layer and said second photoresist layer with the same wavelength of light.