Patent ID: 6600561
Filing Date: 2003-07-29
Classification: G03F

Abstract:
An apparatus for measuring an error of alignment between a first pattern and a second pattern overlappingly formed on a same substrate, a first alignment reference mark of a predetermined symmetric shape being formed at a predetermined position of the substrate during formation of said first pattern, a second alignment reference mark of a predetermined symmetric shape being formed, in predetermined positional relationship to said first alignment reference mark, at a predetermined position of the substrate during formation of said second pattern, said apparatus comprising:a detector that optically detects said first alignment reference mark and said second alignment reference mark formed on the substrate and thereby obtains dimension detection data of said first alignment reference mark or said second alignment reference mark as well as respective position detection data of said first and second alignment reference marks; a determination section that determines respective symmetry centers of said first and second alignment reference marks on the basis of the respective position detection data of said first and second alignment reference marks and determines an error of the alignment between said first and second patterns on the basis of a positional deviation between the determined respective symmetry centers of said first and second alignment reference marks; and an evaluation section that determines whether the dimension detection data of said first alignment reference mark or said second alignment reference mark is within a predetermined reference value range and, if the dimension detection data is within the predetermined reference value range, judges the determination, by said determination section, of the error of the alignment between said first and second patterns to be accurate.