1990 Fiscal Year Final Research Report Summary
Development of Hollow Cathode Type Refractory Metal Ion Source
| Project/Area Number |
63880003
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
プラズマ理工学
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| Research Institution | Tokai University |
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Principal Investigator |
TAKAYAMA Kazuo R&D Institute, Tokai Univ. Prof., 開発技術研究所, 教授 (20023690)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUI Ryota ULVAC O-Project, Oプロジェクト, 主任
YAMAKAWA Hiroyuki ULVAC R&D Division, 技術開発部, 部長
TONEGAWA Akira Dept. of Physics, Tokai Univ. Assist., 理学部物理学科, 助手 (90197905)
SUNAKO Katsuhiko Dept. of Physics, Tokai Univ. Prof., 理学部物理学科, 教授 (50056016)
YABE Eiji R&D Institute, Tokai Univ. Prof., 開発技術研究所, 教授 (70056018)
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| Project Period (FY) |
1988 – 1990
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| Keywords | ion source / double hollow cathode / refractory metal / new sputter mode / metal ion production ratio / high current / ion beam |
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| Research Abstract |
Achievements fo our three-year research project on hollow cathode metal ion source are summarized below. We have developed a double hollow refractory metal ion source in order to increase the metal ion ratio and the ion beam current for new material productions and plasma processing. This ion source consists of two hollow cathode tubes with different diameters, connected inseries and made of refractory materials. The discharge path becomes narrow in the second hollow cathode, which is located between the first hollow cathode and an anode. An axial magnetic field serves to further compress the narrowed discharge path. The role of these structures of the ion source are as follows.
1. A high density plasma is formed inside the narrow canal of the second hollow cathode.
2. A negative high voltage (-800V) is applied to the second hollow cathode with respect to the anode, resulting in sputtering of the refractory material of this cathode.
3. The sputtering efficiency can be increased by increasing the negative voltage without affecting the main discharge conditions.
4. The sputtered refractory materials of the second hollow cathode can be effectively ionized by this high density plasma and a new discharge mode : hollow cathode discharge with inverse magnetron and return motions of beam electron the second hollow cathode. The results of our experiment are as follows.
1. Refractory materials (Mo or Ta) of the second hollow cathode can be effectively sputtered and ionized by this new discharge mode by changing its diameter from 4 to 8 mm.
2. At the sputter voltage from 400 to 700V, the metal ion ratio is -30-50% at the discharge current of 0.8A and magnetic field of 1kG.
3. In this conditions, the total ion beam current obtained is -9mA for a 20kV extracted voltage.
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