Patent ID: 7009197
Filing Date: 2006-03-07
Classification: G01B,G03F

Abstract:
1. An apparatus for measuring a gap between a mask and a substrate, the apparatus comprising: a laser displacement sensor, which is placed on a mask and a substrate spaced apart from each other by a predetermined gap, emits laser beams while moving over the mask and the substrate in a horizontal direction and measures a gap between the mask and the substrate using a variation in distance values measured successively based on light-receiving positions of the laser beams that are reflected from the mask and the substrate, respectively; a Z-direction transferring unit, which adjusts a vertical distance (Z-direction distance) between the laser displacement, the mask, and the substrate; an X-direction transferring unit, which enables the laser displacement sensor to move in a widthwise direction (X direction) in the plane parallel to the mask or the substrate; and a Y-direction transferring unit, which enables the laser displacement sensor to move in a lengthwise direction (Y direction) in the plane parallel to the mask or the substrate.