| 摘要 |
PURPOSE: A method for measuring overlay accuracy is provided to shorten a time interval for measuring the interlayer alignment and perform a stable photolithography process by performing an image filtering process several times so that a pattern for measuring overlay accuracy is recognized in a measuring apparatus. CONSTITUTION: A target pattern(10) for measuring the interlayer alignment and a reference pattern(20) stored in the measuring apparatus are image-filtered. The filtered image patterns are compared to automatically recognize whether the measuring apparatus is a measuring pattern. An image processing method for measuring overlay accuracy is carried out only when the measuring apparatus is recognized as the target pattern for measuring overlay accuracy. The image filtering process is performed at least twice according to different image filtering method to compare the filtered images.
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