Method of Measuring a Characteristic

Abstract

During a multiple patterning process every n th element of the pattern is removed. The removal of the elements of the patterns happens after the pattern has been printed into the radiation sensitive material or etched into substrate. Advantageously, the original mask is not varied, and another exposure step is used to remove the elements of the pattern.

What is claimed is: 
     
         1 . A method comprising:
 exposing a repeating pattern in a layer of resist on a substrate;   transferring the pattern into the substrate;   modifying an element of the pattern;   projecting a beam of radiation onto the pattern; and   measuring the intensity distribution of the reflected radiation beam.   
     
     
         2 . The method of  claim 1 , wherein the modifying comprises removing an element of the pattern. 
     
     
         3 . The method of  claim 1 , wherein the modifying comprises removing every nth element of the pattern. 
     
     
         4 . The method of  claim 1 , wherein the modifying comprises removing a contiguous series of features. 
     
     
         5 . The method of either  claim 1 , wherein the transferring comprises etching the pattern into the substrate. 
     
     
         6 . The method of  claim 1 , wherein the removing comprises:
 covering the substrate with a resist;   covering every nth element of the pattern;   exposing the rest of the substrate to radiation; and   etching the unexposed portions of resist.