In-line holographic mask for micromachining

Abstract

A method of patterning a workpiece comprises providing a source of illumination, a workpiece, a holographic mask and an optical element. The optical element is positioned in the optical path between the source of illumination and the workpiece. The holographic mask is positioned in the optical path between between the source of illumination and the optical element. The holographic mask is illuminated with the source of illumination to form a first real image. The method includes projecting the first real image with the optical element to form a second real image on at least one from the group consisting of the workpiece, a surface of the workpiece, and a location near a surface of said workpiece. A method of patterning a workpiece also includes providing a source of illumination, a holographic mask and a workpiece. The holographic mask is illuminated with the source of illumination to form a three-dimensional real image on the workpiece. The method includes patterning the workpiece based on the three-dimensional real image.

1 . A method of patterning a workpiece, comprising: 
 a) providing a source of illumination;    b) providing a workpiece;    c) providing an optical element in an optical path between said source of illumination and said workpiece;    d) providing a holographic mask, in said optical path between said source of illumination and said optical element;    e) illuminating said holographic mask with said source of illumination to form a first real image; and    f) projecting said first real image with said optical element to form a second real image on at least one from the group consisting of said workpiece, a surface of said workpiece, and a location near a surface of said workpiece.    
   
   
       2 . A method of patterning a workpiece as recited in  claim 1 , wherein said source of illumination includes a laser.  
   
   
       3 . A method of patterning a workpiece as recited in  claim 1 , wherein said source of illumination provides at least one from the group consisting of infra-red, visible, ultraviolet, deep ultra-violet, and x-ray.  
   
   
       4 . A method of patterning a workpiece as recited in  claim 1 , further comprising using said second real image for patterning the workpiece.  
   
   
       5 . A method of patterning a workpiece as recited in  claim 1 , wherein workpiece includes a layer of photosensitive material.  
   
   
       6 . A method of patterning a workpiece as recited in  claim 4 , further comprising using said second real image for exposing said layer of photosensitive material.  
   
   
       7 . A method of patterning a workpiece as recited in  claim 1 , further comprising using said second real image for ablating a pattern in said workpiece.  
   
   
       8 . A method of patterning a workpiece as recited in  claim 1 , wherein said optical element includes a lens.  
   
   
       9 . A method of patterning a workpiece as recited in  claim 1 , wherein said optical element includes at least one from the group including a curved reflector, a fresnel zone plate, a computer-generated hologram, a diffractive optical element, and a binary phase grating.  
   
   
       10 . A method of patterning a workpiece as recited in  claim 1 , wherein said holographic mask includes an in-line holographic mask.  
   
   
       11 . A method of patterning a workpiece as recited in  claim 1 , further comprising an optical axis, wherein said source of illumination, said optical element, said in-line holographic mask and said workpiece are all on said optical axis.  
   
   
       12 . A method of patterning a workpiece as recited in  claim 1 , wherein said source of illumination and said optical element are portions of a photo patterning tool.  
   
   
       13 . A method of patterning a workpiece as recited in  claim 1 , further comprising forming said second real image focused at multiple distances from said optical element.  
   
   
       14 . A method of patterning a workpiece as recited in  claim 1 , wherein said second real image includes a three-dimensional real image.  
   
   
       15 . A method of patterning a workpiece as recited in  claim 14 , further comprising using said three-dimensional real image to form a three-dimensional structure.  
   
   
       16 . A method of patterning a workpiece as recited in  claim 15 , further comprising forming a three-dimensional structure having a high aspect ratio.  
   
   
       17 . A method of patterning a workpiece as recited in  claim 14 , wherein portions of said three-dimensional image that are at different distances from said optical element are in focus.  
   
   
       18 . A method of patterning a workpiece as recited in  claim 14 , further comprising forming a plurality of said three-dimensional real images.  
   
   
       19 . A method of patterning a workpiece as recited in  claim 18 , further comprising using said plurality of three-dimensional real images to form a plurality of three-dimensional structures.  
   
   
       20 . A method of patterning a workpiece as recited in  claim 1 , further comprising fabricating said holographic mask at a construction wavelength, wherein said construction wavelength is different from said source of illumination associated wavelength.  
   
   
       21 . A method of patterning a workpiece as recited in  claim 1 , wherein said in-line holographic mask includes a transparent relief hologram formed in a substrate capable of transmitting electromagnetic energy having a wavelength in the range from IR to x-ray.  
   
   
       22 . A method of patterning a workpiece as recited in  claim 1 , wherein said source of illumination is capable of generating a reconstruction beam extending along an axis and said workpiece holder and said mask are positioned on said axis.  
   
   
       23 . A method of patterning a workpiece, comprising: 
 a) providing a source of illumination;    b) providing a holographic mask;    c) illuminating said holographic mask with said source of illumination to form a three-dimensional real image on said workpiece; and    d) patterning said workpiece based on said three-dimensional real image.    
   
   
       24 . A method of patterning a workpiece, as recited in  claim 23 , wherein said patterning involves providing a three dimensional pattern in a photosensitive material.  
   
   
       25 . A method of patterning a workpiece, as recited in  claim 23 , wherein said patterning involves ablating said workpiece.