1998 Fiscal Year Final Research Report Summary
Spatiotemporal optical emission spectroscopy of atmospheric VHF plasma process
| Project/Area Number |
08405014
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
機械工作・生産工学
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| Research Institution | Osaka University |
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Principal Investigator |
KATAOKA Toshihiko Osaka University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (50029328)
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| Co-Investigator(Kenkyū-buntansha) |
OSHIKANE Yasushi Osaka University, Graduate School of Engineering, Assistant Professor, 大学院・工学研究科, 助手 (40263206)
ENDO Katsuyoshi Osaka University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (90152008)
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| Project Period (FY) |
1996 – 1998
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| Keywords | Atmospheric VHF plasma / Spatiotemporal optical emission spectroscopy / Mean free path / Sheath / Free radicals / Helium |
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| Research Abstract |
Capacitively coupled atmospheric VIF(Very High Frequency) helium plasma was investigated. The plasma chamber was consisted of a cavity resonator and vacuum chamber. VIIF electric power was amplified and is conducted to the vacuum chamber via the resonator.
The plasma was generated in 1 nun gap between the parallel plate electrodes with 150 MHz electric power. The spatiotemporal characteristics of the plasma was diagnosed by optical emission spectroscopy with streak camera.
The resultant spatiotemporal image of the plasma was compared with the exact VHF voltage waveform which appeared on the electrodes. The voltage waveform was indirectry observed as the temporal emission profile of the laser diode which was installed between the gap. As a result of comparison between the waveforms, the plasma emission was occured near the surface of the negative electrode. So the atmospheric VHF plasma was basically negative glow. The sheath width estimated with the spat iotemporal image of the plasma was about 30 micron.
The plasma spectrum of the sheath contained the strong line emission from the helium metastables. Use 388.8Cnm (3^3P*2^3P) line, the metastable number density was measured by absorption spectroscopy with hollow cathode lamp. In the sheath region, the density was about 1.1 * 10^<14> cm^3. This means that the activated region of the plasma could be formed near the surface of the electrode, i.e., semiconductor wafer. The disposition of the atmospheric VHF plasma is advantagious in plasma CVM and atmospheric plasma CVD processes.
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