| 摘要 |
PURPOSE:To prevent crossover position from shifting when changing the beam dimension, by controlling deflecting quantity due to two sets of beam shaping deflectors. CONSTITUTION:Beam paths are made as shown with the solid hold line in the figure when changing the beam dimension. To attain this purpose, each deflecting quantity due to each of first and second deflectors 8, 9 is set so that the deflecting direction of the second deflector 9 can be opposite to that of the first deflector 8 and the deflecting quantity of the second deflector 9 can be larger than that of the first deflector 8. In this way, displacement of the crossover position on the side of the target 7 can be prevented by means of the apertures 3, 4 and the first and second deflectors 8, 9. |
