APPARATUS AND METHODS FOR OVERLAY, ALIGNMENT MARK, AND CRITICAL DIMENSION METROLOGIES BASED ON OPTICAL INTERFEROMETRY

摘要

Methods and apparatus (100, 110) are disclosed for measurement of critical dimensions (CD) of features and detection of defects in reflecting UV, VUV, and EUV lithography masks and in transmitting UV and VUV lithography masks. The measured CD's may be used in the determination of optical proximity corrections (OPC) and/or in mask fabrication process control. The transmitting masks may comprise binary and various types of phase shift masks.