ALIGNMENT KEY SEARCH APPARATUS AND SEARCHING METHOD USING THE SAME FOR EASE SEARCH

摘要

PURPOSE: An alignment key search apparatus and a searching method using the same are provided to search easily an alignment key by using a position value of a center point. CONSTITUTION: A work stage(WS) includes a chuck on which a substrate is loaded. A position detection optic system(100) detects a position of an alignment key formed on the substrate. A stage driver(WF) is used for driving a work stage. A plurality of light emitting units(200) irradiates detecting beams to four places of the edge part of the substrate. A plurality of light receiving units(300) are installed to the substrate corresponding to the light emitting units. A control unit(400) calculates a position value of a center point of the substrate and outputs a position correction signal by using an offset value between the calculated position value and a position value of a center point of the chuck.