Method for creating a color microlens

Abstract

The making and use of color microlenses in color image sensors and color display devices is described and claimed. The color microlenses combine the function of a colorless microlens and a color filter into a single structure simplifying the fabrication of, and increasing the reliability of display devices and image sensors using the described color microlenses.

1 . A method for manufacturing a color microlens array comprising: 
 forming a first colored microlens resist layer on a surface, over a plurality of photodetecting regions that will define an image sensing area of an integrated circuit die;    patterning the first colored microlens resist layer; and    baking the patterned first colored microlens resist layer to cause flowing of the patterned layer resulting in a microlens, with a curved top surface, being formed above each of the plurality of photodetecting regions.    
     
     
         2 . The method of  claim 1  further comprising: 
 repeating the forming, patterning, and baking operations using a second colored microlens resist layer, the second resist layer to filter a different color than the first resist layer.  
 
     
     
         3 . The method of  claim 1  further comprising: 
 fixing the patterned first colored microlens resist layer by deep ultraviolet exposure to cause cross-linking, prior to baking.  
 
     
     
         4 . The method of  claim 1  further comprising: 
 stabilizing a surface of the microlens using silylation.  
 
     
     
         5 . The method of  claim 1  further comprising: 
 exposing the microlens to deep ultra-violet bleaching to improve transparency.  
 
     
     
         6 . The method of  claim 1  wherein the depositing, patterning, and baking operations are repeated three times, each time on a different colored polymer resist layer.  
     
     
         7 . The method of  claim 1  wherein the patterning operation is performed using a photolithographic process.  
     
     
         8 . The method of  claim 1  further comprising planarizing the surface prior to forming the first colored microlens resist layer.  
     
     
         9 . The method of  claim 8  wherein the surface is planarized by spin coating a planarization layer and then baking the spin coated planarization layer.  
     
     
         10 . The method of  claim 9  wherein the planarization layer is of a photo-definable material.  
     
     
         11 . The method of  claim 1  wherein the first microlens resist layer is soft baked prior to being patterned.  
     
     
         12 . The method of  claim 1  wherein the patterning includes exposing the resist layer to ultraviolet light, developing the exposed resist layer, and removing excess resist material from the exposed resist layer.  
     
     
         13 . A method for manufacturing a color microlens array comprising: 
 forming a first colored microlens resist layer on a surface, over a plurality of pixel regions in a color display layer;    patterning the first colored microlens resist layer; and    baking the patterned first colored microlens resist layer to cause flowing of the patterned layer resulting in a microlens, with a curved top surface, being formed above each of the plurality of pixel regions.    
     
     
         14 . The method of  claim 13  further comprising: 
 repeating the forming, patterning, and baking operations using a second colored microlens resist layer, the second resist layer to filter a different color than the first resist layer.  
 
     
     
         15 . The method of  claim 13  further comprising: 
 fixing the patterned first colored microlens resist layer by deep ultraviolet exposure to cause cross-linking, prior to baking.  
 
     
     
         16 . The method of  claim 13  further comprising: 
 stabilizing a surface of the microlens using silylation.  
 
     
     
         17 . The method of  claim 13  further comprising: 
 exposing the microlens to deep ultra-violet bleaching to improve transparency.  
 
     
     
         18 . The method of  claim 13  wherein the depositing, patterning, and baking operations are repeated three times, each time on a different colored polymer resist layer.  
     
     
         19 . The method of  claim 13  wherein the patterning operation is performed using a photolithographic process.  
     
     
         20 . The method of  claim 13  further comprising planarizing the surface prior to forming the first colored microlens resist layer.  
     
     
         21 . The method of  claim 20  wherein the surface is planarized by spin coating a planarization layer and then baking the spin coated planarization layer.  
     
     
         22 . The method of  claim 21  wherein the planarization layer is of a photo-definable material.  
     
     
         23 . The method of  claim 13  wherein the first microlens resist layer is soft baked prior to being patterned.  
     
     
         24 . The method of  claim 13  wherein the patterning includes exposing the resist layer to ultraviolet light, developing the exposed resist layer, and removing excess resist material from the exposed resist layer.