METHOD FOR DETECTING ALIGN MARK USING INVARIANT MOMENT AND APPARATUS THEREOF

摘要

PURPOSE: Alignment mark detection method and device using an invariable moment are provided to detect an alignment mark regardless of the movement, rotation and distortion of the alignment mark by calculating a specific invariable moment using an image on a specific point of a wafer. CONSTITUTION: An alignment mark detection method using an invariable moment is as follows. A specific invariable moment is calculated using an image on a specific point of a wafer(130). The specific invariable moment is compared with the reference-invariable moment which is previously calculated and stored from the image of an alignment mark(140). As a result of the comparison, a specific point of the wafer is established as the location of the alignment mark in case the specific invariable moment is the same to the reference-invariable moment(150).