This work was supported by National High Technology Research and Development Program of PRC (No. 2002AA420040);National 973 Program of PRC (No. 2002CB312200).
In this paper, a new pre-alignment approach based on Four-Quadrant-Photo-Detector (FQPD) for IC mask is presented. The voltage outputs from FQPDs are the functions of alignment mark's position offsets with respect ...