| 摘要 |
PROBLEM TO BE SOLVED: To prevent the leak of a microwave from an ion source, when the size of a plasma chamber is made larger than a critical value, by providing a specific member, in the ion source having constitution where sputter voltage is applied between the plasma chamber and an ion drawing part. SOLUTION: This ion source is provided with a conductive waveguide member 13 and a conductive choke groove member 16. The member 13 abuts on an ion drawing part 2 at one end part to be provided so as to surround the outer wall surface of a plasma chamber (P) 1 main body to transmit a microwave, passed through an insulating member 7, along the outer wall surface of the P:1 main body. The member 16 is provided on the outer surface of the P:1 main body to be connected to the member 13 at a given interval with the other end part of the member 13 in between to reflect the microwave, guided by the member 13 to be transmitted along the outer wall surface of the Pal main body, by a bottom surface 16a. The depth L1 of the groove of the member 16 is set so that the wave lengthλg can be (1/4+N/2)λg, (n: 0, an positive integer), where L1 : the depth of the groove of the member 16,λg: the frequency length of microwave to be transmitted.
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