Compositions and methods involving direct write optical lithography

Abstract

An improved optical photolithography system and method provides predetermined light patterns generated by a direct write system without the use of photomasks. The Direct Write System provides predetermined light patterns projected on the surface of a substrate (e.g., a wafer) by using a computer controlled means for dynamically generating the predetermined light pattern, e.g., a spatial light modulator. Image patterns are stored in a computer and through electronic control of the spatial light modulator directly illuminate the wafer to define a portion of the polymer array, rather than being defined by a pattern on a photomask. Thus, in the Direct Write System each pixel is illuminated with an optical beam of suitable intensity and the imaging (printing) of an individual feature is determined by computer control of the spatial light modulator at each photolithographic step without the use of a photomask. The Direct Write System including a spatial light modulator is particularly useful in the synthesis of DNA arrays and provides an efficient means for polymer array synthesis by using spatial light modulators to generate a predetermined light pattern that defines the image patterns of a polymer array to be deprotected.

What is claimed is:  
     
         1 . A method for deprotecting reaction sites on a substrate comprising the steps of: 
 providing a substrate having protected reaction sites;    modulating light direction with a spatial light modulator so as to generate a predetermined light pattern used for deprotecting selected portions of said protected reaction sites.    
     
     
         2 . The method of  claim 1 , further comprising the step of directing light from a light source to said spatial light modulator.  
     
     
         3 . The method of  claim 2 , further comprising the step of projecting said predetermined light pattern onto a surface of said substrate with a lens.  
     
     
         4 . The method of  claim 3 , further comprising the step of transmitting said predetermined light pattern from said lens through a micro-lens array.  
     
     
         5 . The method of  claim 2 , further comprising the step of transmitting said predetermined light pattern through an array of non-imaging light concentrators.  
     
     
         6 . The method of  claim 4 , further comprising the step of moving said substrate with a translation stage.  
     
     
         7 . The method of  claim 2 , wherein said spatial light modulator is a micro-mirror array.  
     
     
         8 . The method of  claim 7 , wherein said spatial light modulator is a DMD™.  
     
     
         9 . The method of  claim 2 , wherein said spatial light modulator is a GLV™.  
     
     
         10 . The method of  claim 4 , wherein said spatial light modulator is a SVGA DLP™.  
     
     
         11 . The method of  claim 1 , further comprising the step of generating a computer file that specifies, for each photolithography step, which portions of said spatial light modulator will operatively illuminate which portions of said protected reaction sites.  
     
     
         12 . The method of  claim 11 , further comprising the step of programming said spatial light modulator to a desired configuration with information contained in said computer file.  
     
     
         13 . A method of deprotecting reaction sites on a substrate comprising: 
 providing a substrate having protected reaction sites;    providing a light source;    providing a spatial light modulator;    orienting said substrate, said light source, and said spatial light modulator such that when said light source illuminates, intensity of illumination from said light source is modulated by said spatial light modulator and generates a predetermined light image pattern; and    illuminating said substrate with said predetermined light image pattern at said substrate so as to deprotect at least one of said protected reaction sites.    
     
     
         14 . The method of  claim 13 , further comprising the step of projecting said predetermined light pattern onto a surface of said substrate with a lens.  
     
     
         15 . The method of  claim 14 , further comprising the step of transmitting said predetermined light pattern from said lens through a micro-lens array.  
     
     
         16 . The method of  claim 13 , further comprising the step of transmitting said predetermined light pattern through an array of non-imaging light concentrators.  
     
     
         17 . The method of  claim 15 , further comprising the step of moving said substrate with a translation stage.  
     
     
         18 . The method of  claim 13 , wherein said spatial light modulator is a micro-mirror array.  
     
     
         19 . The method of  claim 18 , wherein said spatial light modulator is a DMD™.  
     
     
         20 . The method of  claim 13 , wherein said spatial light modulator is a GLV™.  
     
     
         21 . The method of  claim 15 , wherein said spatial light modulator is a SVGA DLP™.  
     
     
         22 . The method of  claim 13 , further comprising the step of generating a computer file that specifies, for each photolithography step, which portions of said spatial light modulator will operatively illuminate which portions of said protected reaction sites.  
     
     
         23 . The method of  claim 22 , further comprising the step of programming said spatial light modulator to a desired configuration with information contained in said computer file.  
     
     
         24 . An optical lithography system, consisting essentially of: 
 a light source;    a substrate mount; and    a means for dynamically defining a light pattern using unpatterned light from said light source without using a photomask.    
     
     
         25 . The optical lithography system of  claim 24 , wherein said means for dynamically defining a light pattern includes a spatial light modulator module modulating light direction or light intensity to generate a predetermined light image.  
     
     
         26 . The optical lithography system of  claim 24 , wherein said means for dynamically defining a light pattern includes a micro-mirror array modulating light by changing angular position of micro-mirrors in said micro-mirror array.  
     
     
         27 . The optical lithography system of  claim 25 , wherein said spatial light modulator is a DMD™.  
     
     
         28 . The optical lithography system of  claim 25 , wherein said spatial light modulator is a GLV™.  
     
     
         29 . The optical lithography system of  claim 25 , wherein said spatial light modulator is a SVGA DLP™.  
     
     
         30 . The optical lithography system of  claim 29 , wherein said light source includes an arc lamp.  
     
     
         31 . The optical lithography system of  claim 26 , wherein said micro-mirror array includes a plurality of micro-mirrors, each of said micro-mirrors selectively illuminate a single feature on a substrate using specular reflection of light directed toward said substrate (turn on), and selectively not illuminating of said single feature by specular reflection of light directed away from said substrate (turn off).  
     
     
         32 . An optical lithography system, comprising: 
 a spatial light modulator which provides a predetermined two dimensional light pattern on a substrate without use of a photomask and holographic image.    
     
     
         33 . The optical lithography system of  claim 32 , wherein said predetermined two dimensional light image is used for deprotecting reaction sites of a polymer array.  
     
     
         34 . The optical lithography system of  claim 33 , further comprising a light source.  
     
     
         35 . The optical lithography system of  claim 34 , wherein said light source includes an arc lamp.  
     
     
         36 . The optical lithography system of  claim 35 , wherein said spatial light modulator includes a micro-mirror array modulating light by changing angular position of micro-mirrors in said micro-mirror array.