Method for making micro lenses

Abstract

A micro lens, or an array of micro lenses, can be formed without requiring the etching of a mesa into the substrate by deposited directly on the substrate, without any mesa each of the individual portions of the substance to be melted. The whole substrate and the portions are then conformally coated with a very thin layer of a substance, typically an adhesion promoter, e.g., hexamethyldisilazane (HMDS). The entire coated wafer is then subject to conditions which cause each of the individual substance portions to flow into a lens shape. A lens shape is achieved without requiring a mesa because the layer of adhesion promoter prevents the flowing substance from spilling in an undesired manner over the surface of the substrate.

1 - 20 . (canceled)  
   
   
       21 . A micro lens array formed on a substrate, each micro lens of said array being characterized in that it has no visible mesa after its manufacture.  
   
   
       22 . A method for making at least one micro lens comprising the steps of: 
 depositing at least one individual portion of a substance to be flowed on a substrate so that said at least one individual portion of said substance to be flowed has a prescribed footprint; and    pinning, with a conformal coating of a prescribed coating material, said at least one individual portion of said substance to be flowed substantially to said footprint so that when said substance to be flowed is exposed to conditions which cause it to flow said substance to be flowed is formed into a lens shape having said footprint.    
   
   
       23 . The invention as defined in  claim 22  wherein said prescribed coating material comprises an adhesion promoter.  
   
   
       24 . The invention as defined in  claim 22  wherein said conformal coating is a coating of hexamethyldisilazane (HMDS).  
   
   
       25 . A micro lens which was formed from a portion of a substance which was flowed, said substance which was flowed having been contained in at least an initial footprint substantially only by a conformal coating of a prescribed coating material at least traces of which are detectable in the immediate vicinity of said micro lens.  
   
   
       26 . The invention as defined in  claim 25  wherein said substance which was flowed comprises a positive photoresist.  
   
   
       27 . The invention as defined in  claim 25  wherein said initial footprint is modified by further etching said at least one micro lens.  
   
   
       28 . The invention as defined in  claim 25  wherein said at lest one micro lens is a member of an array of a plurality of micro lenses.  
   
   
       29 . The invention as defined in  claim 25  wherein said conformal coating is a mono layer.  
   
   
       30 . At least one micro lens manufactured by a process which comprises the steps of: 
 depositing at least one individual portion of a substance to be flowed on a substrate;    coating with a prescribed coating material said at least one individual portion of said substance to be flowed and at least the immediate surrounds on said substrate of said at least one individual portion;    exposing said coated substrate and coated portions of said substance to be flowed to conditions which cause said substance to be flowed to flow; and    whereby said substance to be flowed forms a lens shape without requiring formation of a mesa for said portion of substance to be flowed.    
   
   
       31 . The invention as defined in  claim 30  wherein said prescribed coating material is an adhesion promoter.  
   
   
       32 . The invention as defined in  claim 30  wherein said prescribed coating material is hexamethyldisilazane (HMDS).  
   
   
       33 . The invention as defined in  claim 30  wherein said portion of a substance to be flowed is photoresist.  
   
   
       34 . The invention as defined in  claim 30  wherein said at least one micro lens is an array of a plurality of micro lenses each originating from its own respective individual portion of said substance to be flowed.  
   
   
       35 . The invention as defined in  claim 30  wherein said at least one micro lens is an array of a plurality of micro lenses at least one two of which originate from a single individual portion of said substance to be flowed.  
   
   
       36 . The invention as defined in  claim 21  wherein said micro lens array is manufactured by a process comprising the steps of: 
 depositing a plurality of individual portions of a substance to be flowed on a substrate;    coating with a prescribed coating material each of said individual portions of said substance to be flowed and at least the immediate surroundings on said substrate of said individual portions;    exposing said coated substrate and coated portions of said substance to be flowed to conditions which cause said substance to be flowed to flow; and    whereby each of said individual portions of said substance to be flowed forms a lens shape without requiring formation of a mesa for each of said individual portions of substance to be flowed.    
   
   
       37 . The invention as defined in  claim 21  wherein said micro lens array is manufactured by a process comprising the steps of: 
 depositing a plurality of individual portions of a substance to be flowed on a substrate so that said each of said individual portions of said substance to be flowed has a respective prescribed footprint at the location at which it was deposited; and    pinning, with a conformal coating of a prescribed coating material, each of said individual portions of said substance to be flowed substantially to its respective prescribed footprint so that when said substance to be flowed is exposed to conditions which cause it to flow said substance to be flowed at each respective location is formed into a lens shape having its respective prescribed footprint.