| 摘要 |
<P>PROBLEM TO BE SOLVED: To expand a variable range of a beam current of an ion beam. <P>SOLUTION: This ion source 65 has: a microwave power control device 13, a microwave transmitter 15, a discharge vessel 19, and electrodes 21a, 21b and 21c. The control device 13 is connected to the transmitter 15 through a cable 14. Plasma is generated by entering microwaves into the discharge vessel 19, and ions in the plasma are changed into an ion beam 23 and emitted from the ion source 65. The control device 13 controls the transmitter 15 and reduces the power of the microwaves 16 in the middle of pulses lower than the lowest power P<SB>C</SB>capable of igniting discharge. Thereby, a pulse ion beam having an ion beam current lower than a current value corresponding to the lowest power P<SB>C</SB>for igniting discharge is obtained. <P>COPYRIGHT: (C)2004,JPO |
