| 摘要 |
<p>PURPOSE:To repair the white and black defects of a mask precisely by correcting the repair range of a repair pattern on a memory at every scan based on movement information on a reference pattern image resulting from a shift in ion beam spot position with the change with the lapse of time. CONSTITUTION:The repair range is inputted to a repair range specifying circuit 22 and an optional pattern on the mask is inputted as a reference pattern to a circuit 25. Then, the indexes I and K of a counter 26 are initialized and set to 1 respectively. In this case, I specifies a reference interval and K specifies the number of times of frame specification for repair scans. The reference pattern specified range is scanned with an ion beams to store image information in a memory 20. Further, the repair range is stored as a bit map in a storage circuit 23. Then I and K are increased at every one frame scan and repairing operation is repeated. Obtained image information is stored in a storage circuit 19 and compared with image information in the memory 20 to calculate the quantity of reference pattern movement, and the bit map in the circuit 23 is corrected based on it.</p> |
