IN-SITU OR EX-SITU PROFILE MONITORING OF PHASE OPENINGS ON ALTERNATING PHASE SHIFTING MASKS BY SCATTEROMETRY

摘要

A system for monitoring and controlling aperture etching in an alternating aperture phase shift mask (170, 270, 370, 722) is provided. The system includes one or more light sources (744, 762, 844), each light source (744, 762, 844) directing light to one or more apertures (150, 160, 250, 260, 350, 360, 430, 504, 506, 508, 604, 610, 612, 724, 824, 924) etched on a mask (420, 922). Light reflected from the apertures (150, 160, 250, 260, 350, 360, 430, 504, 506, 508, 604, 610, 612, 724, 824, 924) is collected by a measuring system (750, 850), which processes the collected light. The collected light is indicative of properties including the depth, width and/or profile of the openings on the mask (420, 922). The measuring system (750, 850) provides such depth, width and/or profile related data to a processor (760, 860, 1210) that determines the acceptability of the aperture (150, 160, 250, 260, 350, 360, 430, 504, 506, 508, 604, 610, 612, 724, 824, 924) and/or the mask (420, 922). The system also includes a plurality of etching devices (150, 160, 250, 260, 350, 360, 430, 504, 506, 508, 604, 610, 612, 724, 824, 924) in the mask (420, 922). The processor (760, 860, 1210) may selectively control the etching devices (450, 480) so as to regulate aperture etching.