| 摘要 |
When the focal point of the objective lens of a charged-particle beam lithographic system is shifted according to the deflection position within a writing field, the image magnification of the objective lens will vary. In the present invention, the focal point of the objective lens is shifted in a corresponding manner to deflection positions in X- and Y-directions, respectively. Amounts of variations in the image magnification are previously measured, as well as the amounts of shifts. The results are stored in a memory. During lithographic writing, the focus of the objective lens is varied by referring to the memory according to the deflection positions. The size and position of a pattern to be written are corrected by controlling a shaping deflector and a positioning deflector.
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