Holographic Optical Processing For Submicrometer Defect Detection

A holographic optical processor has been built for efficient, fast, wide-field detection of submicrometer defects in repetitive subject formats such as integrated circuit photomasks. This paper describes the advantages gained by combining holography with standard optical processing techniques and presents results obtained on a 2 in. field-of-view prototype and 7 in. field-of-view fully automated mask inspection system.