Patent ID: 8964173
Filing Date: 2015-02-24
Classification: G01B

Abstract:
1. A method of measuring spot beam positions of an optical maskless exposure system, the method comprising: measuring positions of a plurality of fiducial marks (FMs) engraved on a fiducial beam measurement system (BMS) mark array (FBA) installed on a movable table using spot beams irradiated from a plurality of optical systems and a plurality of BMSs installed on the movable table; calculating central position coordinates of the BMSs using position information of the FMs of the FBA and displacements of the FMs measured by the respective BMSs; acquiring image information of spot beams irradiated from the optical systems using the BMSs; and measuring positions of the spot beams using a position of the movable table, positions of the plurality of BMSs and the image information acquired by the BMSs.