Dynamic blanking control of single column multi-electron-beam system

Dynamic individual beam control in a multi-electron-beam system was demonstrated. In a multi-beam system, individual beam blanking and accurate correction of each beam position and irradiation dose are essential. In this paper, 16 beams in a 1024-beam system were individually blanked at 100-MHz frequency. Individual beam blanking was verified by pattern delineation. The beam position was corrected by the data shift through the feedback from the positions of formerly delineated patterns. The irradiation dose was corrected by measuring the dose of each beam and calibrating the irradiation time. Moreover, a movable blanking aperture was installed to improve the uniformity of blanking control. Finally, these corrections were evaluated by measuring the line widths in delineated patterns smaller than 65 nm. As a result, positioning accuracy within 1 pixel and dose deviation within 2.4% were achieved. In conclusion, it was clarified that our multi-beam-system has potential applications in