| 摘要 |
PROBLEM TO BE SOLVED: To raise the throughput of a blanking aperture array system of charged particle beam exposure system, by setting the current value of a constant current source so that the actual scan speed may come to the specified scan speed, using the one where the current value is variable, as the constant current source. SOLUTION: Defining that the output current of a digital-analog converter 46 for converting scan coefficient into an analog current signal is I, that the capacitance of a capacitor 47 is C, and that the time of one scan is T, the voltage of the capacitor 47 changes continuously accompanying the change of time, and the change of the voltage value during one scan is I×T/C. Accordingly, when the output current is set at a specified positive value, with the output voltage V1 of a current-voltage converting circuit 44, the voltage of the capacitor 47 increases gradually, and the voltage of an addition circuit 48 at the finish of the scan becomes V1+ΔV, and when the output current is set at a specified negative value, the voltage of the capacitor 47 decreases gradually, and at the finish of the scan, the voltage of the addition circuit 48 returns to V1.
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