Alignment method, alignment apparatus, and exposure apparatus

An alignment apparatus 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 apparatus comprising:

• an image processing section which detects 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 imaging device having the light receiving elements arranged in a straight line in a direction perpendicular to a conveying direction of the object to be exposed, adds 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, obtains a plurality of edge count data arranged corresponding to the detected positions of the brightness changes, obtains 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, and identifies 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;
• an arithmetic section which selects a position of the closest pattern to a target position preset in the imaging device from the identified positions of the plurality of patterns and calculates the amount of a position displacement between the selected position of the pattern and the target position of the imaging device;
• and
• an alignment apparatus which relatively moves 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.

An exposure apparatus for exposing an object to be exposed with uniform patterns arranged in a matrix and being conveyed in a direction with a photomask aligned with the object to be exposed, the exposure apparatus comprising:

• a light source which emits an ultraviolet light;
• a mask stage which holds the photomask so as to be opposite to and close to a surface of the object to be exposed being conveyed;
• an imaging device which has 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 and captures an image of the object at a position spaced apart a certain distance in the opposite direction of the conveying direction of the exposure position with the photomask;
• and
• an alignment apparatus which detects positions of brightness changes in an arrangement direction of the light receiving elements by sequentially processing a plurality of images captured at regular time intervals by the imaging device, adds 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, obtains a plurality of edge count data arranged corresponding to the detected positions of the brightness changes, obtains 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, and identifies 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, selects a position of the closest pattern to a target position preset in the imaging device from the identified positions of the plurality of patterns, calculates the amount of a position displacement between the selected position of the pattern and the target position of the imaging device, and relatively moves at least the mask stage 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.