Patent ID: 9069266
Filing Date: 2015-06-30
Classification: G03F

Abstract:
1. An alignment method for aligning a photomask with an object to be exposed with uniform patterns arranged in a matrix and being conveyed in a direction, the alignment method comprising the steps of: detecting positions of brightness changes in an arrangement direction of a plurality of light receiving elements by sequentially processing a plurality of images captured at regular time intervals by an imaging device having a plurality of light receiving elements arranged in a straight line in a direction perpendicular to a conveying direction of the object to be exposed; obtaining a plurality of edge count data arranged corresponding to the detected positions of the brightness changes by adding up, in the conveying direction of the object to be exposed, the number of brightness changes detected at the same position in the arrangement direction of the light receiving elements while the object to be exposed moves by a certain distance; obtaining a plurality of correlation value data by performing a correlation operation for the plurality of calculated edge count data while moving a template, on which a unit edge count data is preset for a pattern having the same shape as the pattern, from one end toward the other end in the arrangement direction of the plurality of calculated edge count data; identifying the positions of the plurality of patterns based on a plurality of correlation value data exceeding a predetermined threshold value in the plurality of correlation value data; selecting the position of the closest pattern to a target position preset in the imaging device from the identified positions of the plurality of patterns; calculating the amount of a position displacement between the selected position of the pattern and the target position of the imaging device; and relatively moving at least the photomask in the direction perpendicular to the conveying direction of the object to be exposed so that the amount of the position displacement is a predetermined value to perform alignment between the photomask and the object to be exposed.