| 摘要 |
PURPOSE:To make it possible to suppress an occurrence of an impurity as much as possible and to stably generate main discharge by providing intermediate electrodes disposed between two adjacent main electrodes and a voltage applying circuit for applying a voltage to these intermediate electrodes and attracting charged particles discharged from a charged-particle supply source. CONSTITUTION:If a switch 16 is open, a capacitor 14 for charging/discharging is charged from high-voltage power supplies H, V through a charging resistor 15. In a voltage applying circuit 24, a capacitor 26 is charged from high-voltage power supplies H, V through a charging resistor 25. In this case, the charging is performed at a speed determined by the time constant determined by the charging resistor 25, the capacitor 26 and a coil 27. As a result of charging this capacitor 26, this charged voltage is applied to an intermediate electrode 23. Furthermore, in a charged-particle supply source 18, a high frequency power is supplied to both electrodes 20, 21 from a high-frequency AC power supply 22. As a result, charged particles -e are emitted from an insulator 19. |
