Alignment method and apparatus and exposure apparatus

Abstract

A method for detecting disposition of plurality of exposure shot areas of an object that is to be exposed includes a first detection step of detecting the alignment marks on the object, an evaluation step of evaluating randomness of the alignment marks based on the detection result by the first detection step, a determination step of determining a number smaller than the total number of alignment marks on the object based on the evaluation result by the evaluation step, and a second detection step of detecting the disposition of the plurality of exposure shot areas by detecting alignment marks corresponding to the number determined by the determination step.

1 . A method of detecting disposition of a plurality of shot areas on an object, the plurality of shot areas being exposed to a pattern in accordance with the detected disposition, said method comprising: 
 a first detection step of detecting an alignment mark in the plurality of shot areas, the alignment mark including elements that have an interval therebetween;    an evaluation step of evaluating reproducibility of the interval of the detected alignment mark;    a determination step of determining a number of alignment marks in the plurality of shot areas based on the evaluated reproducibility; and    a second detection step of detecting the disposition of the plurality of shot areas by detecting a plurality of alignment marks in the plurality of shot areas, a number of the plurality of alignment marks having been determined by said determination step.    
   
   
       2 . A method according to  claim 1 , wherein said evaluation step evaluates the reproducibility based on a standard deviation of a plurality of the interval of a plurality of the detected alignment mark.  
   
   
       3 . An apparatus for detecting disposition of a plurality of shot areas on an object, the plurality of shot areas being exposed to a pattern in accordance with the detected disposition, said apparatus comprising: 
 a detector configured to detect alignment mark in the plurality of shot areas, the alignment mark including elements that have an interval therebetween;    a processor configured to evaluate reproducibility of the interval of the detected alignment mark, to determine a number of alignment marks in the plurality of shot areas based on the evaluated reproducibility, to cause said detector to detect the determined number of alignment marks in the plurality of shot areas, and to detect the disposition of the plurality of shot areas based on the detection of the determined number of alignment marks.    
   
   
       4 . An exposure apparatus for exposing an object to a pattern, said apparatus comprising an apparatus as defined in  claim 3  for detecting disposition of a plurality of shot areas on the object.  
   
   
       5 . A method of inspecting an overlay state between a first mark and a second mark in each of a plurality of shot areas on an object, a film being formed on the first mark, the second mark formed on the film, each of the plurality of shot areas having been formed through an exposure of the object to a pattern, said method comprising: 
 a first detection step of detecting the first mark in the plurality of shot areas, the first mark including elements that have an interval therebetween;    an evaluation step of evaluating reproducibility of the interval of the detected first mark;    a determination step of determining based on the evaluated reproducibility of the plurality of shot areas with respect to each of which the overlay state is to be inspected; and    a second detection step of detecting the overlay state in each of the plurality of shot areas, a number of which having been determined by said determination step.    
   
   
       6 . An apparatus for inspecting an overlay state between a first mark and a second mark in each of a plurality of shot areas on an object, a film being formed on the first mark, the second mark formed on the film, each of the plurality of shot areas having been formed through an exposure of the object to a pattern, said apparatus comprising: 
 a detector configured to detect the first mark in the plurality of shot areas, the first mark including elements that have an interval therebetween; a processor configured to evaluate reproducibility of the interval of the detected first mark, to determine, based on the evaluated reproducibility, a number of the plurality of shot areas with respect to each of which the overlay state is to be inspected, to cause said detector to detect the first mark and the second mark in each of the determined number of shot area, and to detect the overlay state with respect to each of the determined number of shot areas based on the detection of the first mark and the second mark in each of the determined number of shot areas.