| 摘要 |
A photomask inspection apparatus includes a photoelectric converting portion, a first comparator, buffer memories, a design data converting portion, and second and third comparators. The photoelectric converting portion converts the respective beams of light having separately scanned adjoining identical unit patterns formed on a photomask into electrical signals. The first comparator compares these electrical signals with each other to find whether there is any inconformity between the unit patterns, and when any inconformity is found, the first comparator outputs coordinate information of the inconformity. The buffer memories store the electrical signals respectively when the inconformity is found by the first comparator. The design data converting portion converts only design data of peripheral coordinates of the coordinate information in the design data stored in the external memory into an inspection signal. The second and third comparators compare the electrical signals from the buffer memories with the inspection signal to identify a photomask pattern having a defect. |
