Method For Fracturing And Forming A Pattern Using Shaped Beam Charged Particle Beam Lithography

Abstract

In the field of semiconductor production using shaped charged particle beam lithography, a method and system for fracturing or mask data preparation or proximity effect correction is disclosed, wherein a series of curvilinear character projection shots are determined for a charged particle beam writer system, such that the set of shots can form a continuous track, possibly of varying width, on a surface. A method for forming a continuous track on a surface using a series of curvilinear character projection shots is also disclosed. Methods for manufacturing a reticle and for manufacturing a substrate such as a silicon wafer by forming a continuous track on a surface using a series of curvilinear character projection shots is also disclosed.

1 . A method for fracturing or mask data preparation, the method comprising the steps of:
 inputting a non-circular target pattern to be formed on a surface; and   determining a plurality of shaped beam shots that form a pattern on the surface using charged particle beam lithography, wherein the plurality of shaped beam shots comprises a plurality of circular or nearly-circular character projection (CP) shots plus one or more non-circular shots, wherein at least two shots in the plurality of circular or nearly-circular shots overlap, and wherein the pattern on the surface matches the target pattern within a pre-determined tolerance.   
     
     
         2 . The method of  claim 1  wherein the plurality of circular or nearly-circular CP shots forms the perimeter of the pattern on the surface. 
     
     
         3 . The method of  claim 1  wherein the one or more non-circular shots comprises a variable shaped beam (VSB) shot. 
     
     
         4 . The method of  claim 1  wherein each shot in the plurality of shaped beam shots comprises an assigned dosage, and wherein the assigned dosages of shots in the plurality of shaped beam shots vary with respect to each other before dosage correction. 
     
     
         5 . The method of  claim 1  wherein the step of determining comprises calculating a calculated pattern that will be formed on the surface using the plurality of shaped beam shots. 
     
     
         6 . The method of  claim 5  wherein the calculating comprises charged particle beam simulation. 
     
     
         7 . The method of  claim 6  wherein the charged particle beam simulation includes at least one of a group consisting of forward scattering, backward scattering, resist diffusion, Coulomb effect, etching, fogging, loading and resist charging. 
     
     
         8 . The method of  claim 5  wherein the step of determining comprises using an optimization technique. 
     
     
         9 . The method of  claim 8  wherein the optimization technique reduces shot count or write time. 
     
     
         10 . The method of  claim 1  wherein the surface is a reticle to be used in an optical lithography process to manufacture a substrate. 
     
     
         11 . The method of  claim 1  wherein the non-circular target pattern is curvilinear. 
     
     
         12 . The method of  claim 1  wherein the step of determining uses a correct-by-construction technique. 
     
     
         13 . The method of  claim 1 , further comprising the step of inputting information about one or more circular or nearly-circular characters available on a stencil for the charged particle beam lithography. 
     
     
         14 - 35 . (canceled)