Method and system for forming a pattern on a surface using multi-beam charged particle beam lithography

Abstract

A method for fracturing or mask data preparation is disclosed in which a plurality of single-beam charged particle beam shots is used to create a plurality of multi-beam shots, where multi-beam exposure information is determined for each of the single-beam shots, and then the resulting multi-beam exposure information is used to generate a set of multi-beam shots. Additionally, a method for fracturing or mask data preparation is disclosed in which a plurality of single-beam shots is used to generate a set of multi-beam shots by calculating an image which the single-beam shots would form on a surface.

What is claimed is: 
     
         1 . A method for fracturing or mask data preparation of a pattern to be formed on a surface using multi-beam charged particle beam lithography, the method comprising:
 inputting a set of single-beam charged particle beam shots;   calculating a calculated image using the set of single-beam charged particle beam shots; and   generating a set of multi-beam shots based on the calculated image, to convert the set of single-beam charged particle beam shots to the set of multi-beam shots which will produce a surface image on the surface, wherein the surface image matches the calculated image, within a pre-determined tolerance, and wherein the generating is performed using a computing hardware processor.   
     
     
         2 . The method of  claim 1  wherein the pattern comprises one or more patterns, and wherein the calculated image comprises contour information for the one or more patterns. 
     
     
         3 . The method of  claim 2  wherein the calculated image comprises dose margin information for the one or more patterns. 
     
     
         4 . The method of  claim 1  wherein the calculated image comprises an aerial image. 
     
     
         5 . The method of  claim 1  wherein each multi-beam shot comprises a plurality of beamlets. 
     
     
         6 . The method of  claim 1  wherein shots in the set of single-beam charged particle beam shots comprise assigned dosages. 
     
     
         7 . The method of  claim 1  wherein shots in the set of single-beam charged particle beam shots have no assigned dosages. 
     
     
         8 . The method of  claim 1  wherein shots in the set of single-beam charged particle beam shots overlap. 
     
     
         9 . The method of  claim 1  wherein shots in the set of single-beam charged particle beam shots comprise variable shaped beam (VSB) shots. 
     
     
         10 . The method of  claim 1  wherein the calculating comprises charged particle beam simulation. 
     
     
         11 . The method of  claim 10  wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, fogging, loading and resist charging. 
     
     
         12 . The method of  claim 1  wherein the pattern comprises one or more patterns, wherein the multi-beam charged particle beam lithography comprises exposing a plurality of pixels or beamlets, and wherein the step of generating comprises:
 determining pixel or beamlet dosage information for each of the patterns in the one or more patterns; and 
 generating the set of multi-beam shots from the pixel or beamlet dosage information for the one or more patterns. 
 
     
     
         13 . A method for fracturing or mask data preparation of a pattern to be formed on a surface using multi-beam charged particle beam lithography, the method comprising:
 inputting a set of single-beam charged particle beam shots;   selecting a first single-beam shot in the set of single-beam charged particle beam shots;   determining, based on the first single-beam shot, a first multi-beam exposure information which will produce an exposure which matches the first single-beam shot, within a pre-determined tolerance;   selecting a second single-beam shot in the set of single-beam charged particle beam shots;   determining, based on the second single-beam shot, a second multi-beam exposure information which will produce an exposure which matches the second single-beam shot, within the pre-determined tolerance; and   generating a set of multi-beam shots using the first multi-beam exposure information and the second multi-beam exposure information, to convert the set of single-beam charged particle beam shots to the set of multi-beam shots, wherein the set of multi-beam shots is to be used to form the pattern on the surface, wherein the generating is performed using a computing hardware processor.   
     
     
         14 . The method of  claim 13 , wherein the first multi-beam exposure information and the second multi-beam exposure information each comprise a dosage for each of a plurality of beamlets or pixels. 
     
     
         15 . The method of  claim 13  wherein the generating comprises:
 combining the first multi-beam exposure information and the second multi-beam exposure information to create a combined multi-beam exposure information; and 
 determining one or more multi-beam shots which together produce the combined multi-beam exposure information. 
 
     
     
         16 . The method of  claim 15  wherein the first multi-beam exposure information and the second multi-beam exposure information each comprise a dosage for each of a plurality of beamlets or pixels, and wherein the combining comprises combining dosages on a pixel-by-pixel or beamlet-by-beamlet basis. 
     
     
         17 . The method of  claim 16  wherein dosages are combined by addition. 
     
     
         18 . The method of  claim 13  wherein each multi-beam shot comprises a plurality of beamlets. 
     
     
         19 . The method of  claim 13  wherein shots in the set of single-beam charged particle beam shots comprise assigned dosages. 
     
     
         20 . The method of  claim 13  wherein shots in the set of single-beam charged particle beam shots overlap. 
     
     
         21 . The method of  claim 13  wherein shots in the set of single-beam charged particle beam shots comprise variable shaped beam (VSB) shots.