Method and apparatus for a reticle with purged pellicle-to-reticle gap

Abstract

A method and apparatus for maintaining a purged optical gap between a pellicle and a reticle in a photolithography system. A frame between a reticle and a pellicle maintains the purged optical gap. The frame defines first and second opposing surfaces. The first opposing surface defines a first opening, and is configured to mate with the pellicle. The second opposing surface defines a second opening, and is configured to mate with the reticle to enclose the optical gap between the pellicle and the reticle. At least one edge of the frame has an opening therethrough. A porous sintered material fills each opening through an edge of the frame.

1 - 20 . (canceled)  
   
   
       21 . An apparatus for maintaining a gap between a pellicle and a reticle in a photolithography system, comprising: 
 a frame having first and second opposing surfaces, said first opposing surface being configured to mate with the pellicle and said second opposing surface being configured to mate with the reticle, wherein said frame encloses the gap between the pellicle and the reticle, wherein at least one edge of said frame has an opening therethrough; and    a porous sintered material that fills said opening in said at least one edge of said frame.    
   
   
       22 . The apparatus of  claim 21 , wherein said porous sintered material filters gas passing into said gap through said at least one edge of said frame.  
   
   
       23 . The apparatus of  claim 21 , further comprising: 
 a gas supply interface for infusing a purge gas through said porous sintered material into said gap.    
   
   
       24 . The apparatus of  claim 23 , further comprising a vacuum source interface for evacuating said purge gas from said gap.  
   
   
       25 . The apparatus of  claim 24 , wherein said vacuum source interface evacuates said purge gas from said gap through said porous sintered material.  
   
   
       26 . The apparatus of  claim 21 , further comprising: 
 a gas supply interface for infusing a purge gas through said frame, wherein said gas supply interface comprises a hole in an edge of said frame through which purge gas enters into said gap.    
   
   
       27 . The apparatus of  claim 21 , wherein said porous sintered material comprises at least one of iron, copper, nickel, and titanium.  
   
   
       28 . The apparatus of  claim 21 , wherein said porous sintered material is in the form of at least one insert that is positioned in said opening in said at least one edge of said frame.  
   
   
       29 . The apparatus of  claim 21 , wherein said opening in said at least one edge of said frame is rectangular shaped.  
   
   
       30 . The apparatus of  claim 21 , wherein said opening in said at least one edge of said frame is substantially round shaped.  
   
   
       31 . The apparatus of  claim 21 , wherein said opening in said at least one edge of said frame is substantially elliptical shaped.  
   
   
       32 . A photolithography system, comprising: 
 a pellicle;    a reticle in optical alignment with said pellicle;    a frame disposed between said pellicle and said reticle to enclose a gap therebetween, wherein at least one edge of said frame has an opening therethrough; and    a porous sintered material that fills said opening in said at least one edge of said frame.    
   
   
       33 . The system of  claim 32 , further comprising: 
 a gas supply interface coupled to said frame for infusing a purge gas through said frame and into said gap.    
   
   
       34 . The system of  claim 32 , further comprising a vacuum source interface coupled to said frame for evacuating said purge gas from said gap through said frame.  
   
   
       35 . The system of  claim 32 , wherein said porous sintered material comprises at least one of iron, copper, nickel, and titanium.  
   
   
       36 . The system of  claim 32 , wherein said porous sintered material is in the form of at least one rectangular insert that is positioned in said opening in said at least one edge of said frame.  
   
   
       37 . The system of  claim 32 , wherein said opening in said at least one edge of said frame is rectangular shaped.  
   
   
       38 . A method for maintaining a filtered pellicle-to-reticle gap in a photolithography system, comprising: 
 (a) forming a gap within a frame between a reticle and pellicle;    (b) positioning a porous sintered material insert into an opening in at least one edge of the frame; and    (c) passing a purge gas into the gap through the frame.    
   
   
       39 . The method of  claim 38 , wherein step (a) comprises the steps of: 
 (1) attaching a pellicle to a first open surface of the frame; and    (2) attaching a reticle to a second open surface of the frame to form the gap within the frame between the reticle and the pellicle.    
   
   
       40 . The method of  claim 38 , further comprising the step of: 
 (c) filtering the purge gas passed through the frame with the porous sintered material insert positioned in the opening in at least one edge of the frame.    
   
   
       41 . An apparatus for maintaining a gap between a pellicle and a reticle in a photolithography system, comprising: 
 a frame having first and second opposing surfaces, said first opposing surface being configured to mate with the pellicle and said second opposing surface being configured to mate with the reticle, wherein said frame encloses the gap between the pellicle and the reticle, wherein at least one edge of said frame has an opening therethrough; and    a porous material that fills said opening in said at least one edge of said frame;    wherein said porous material has a coefficient of thermal expansion (CTE) equal or substantially equal to that of Invar.    
   
   
       42 . The apparatus of  claim 41 , wherein said porous material is a porous sintered material.  
   
   
       43 . The apparatus of  claim 42 , wherein said porous sintered material comprises at least one of iron, copper, nickel, and titanium.