PURPOSE: To reduce the maintainance and inspection work for an ion source by providing a plasma-generating electrode for high-frequency discharge.
CONSTITUTION: A discharge chamber 1 is formed by a cylindrical side plate 2 and a side-plate blocking lid plate 3. A plasma-generating electrode 4 is provided at approximately the center of the chamber 1 in such a manner as passing the center of the lid plate 3. A radiation shield 22 is located immediately in front of the plasma electrode 8 of a take out electrode system 11 and a columnar space is defined by a radiation shield 5 located on the inner periphery of the chamber 1 and by an intermediate radiation shield 6. Plasma is generated within the space. A cathode filament 7 heats the plasma space. The side shield 5 and the intermediate shield 6 are at the same anode potential as the chamber 1. High-frequency power is fed among the chamber 1, the electrode 4 and the shields 5,6 and thereby high-frequency discharge is generated between the electrode 4 and each of the shields 6,5 and excites and converts a vapor into plasma.
YAMASHITA TAKATOSHI
FUJIWARA SHUICHI
MATSUDA YASUHIRO
MATSUNAGA KOJI
INAI YUTAKA
