1998 Fiscal Year Final Research Report Summary
Diagnostics of Processing Plasmas Using Optical Emission Spectroscopic and Mass Spectrometric Methods
| Project/Area Number |
09650338
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Muroran Institute of Technology |
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Principal Investigator |
ITOH Hidenori Muroran Institute of Technology, Professor, 工学部, 教授 (70136282)
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| Co-Investigator(Kenkyū-buntansha) |
SATOH Kohki Muroran Institute of Technology, A.Professor, 工学部, 助教授 (50235339)
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| Project Period (FY) |
1997 – 1998
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| Keywords | RF plasma / plasma diagnostics / optical emission spectroscopic method / mass spectrometric method / spatiotemporally resolved profile / excitation molecule / image intensifier / modeling(continue to next page) |
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| Research Abstract |
A plasma diagnostic system composed of optical emission spectroscopic equipment and mass spectrometric one has been developed. This system enables us to obtain time- and space-resolved optical emission spectra and measure ions incident on the grounded electrode simultaneously.
The characteristics of radio frequency (RF) plasmas as a function of driving frequency f, 0.1 - 13.56 MHz in nitrogen have been investigated by the developed system. The spatiotemporally resolved profiles of the net excitation rate of molecules and ions, for example C^3II_u, and B^2SIGMA_U^+ states have been deduced from time resolved optical emission profiles of the second positive band and the first negative band, respectively. The ions incident on the grounded electrode, have been also measured using a quadrupole mass spectrometer (QMS). It is found that ionizations due to the secondary electrons from the electrodes by ions play an important part in the maintaining mechanism at low frequency as f<1.5 MHz, while a discharge is maintained by bulk ionizations at high frequency as 10 MHz. The results also show that a discharge at middle frequency as 1.5<f<10 MHz, is explained from the point of view of the transition of the mechanism which maintain a discharge.
A self-consistent computer modeling of the plasma kinetics of RF plasmas in nitrogen has been also carried out parallel to the experimental work. The modeling is performed using a one-dimensional Propagator method coupled with Poisson's equation and external circuit equations. It is found that the profiles of spatio-temporal variations of excitation rate for C^3II_u state at 13.56 MHz qualitatively agree with those obtained from the optical emission spectroscopy measurements.
Our next subject of research is the application of the plasma diagnostic system developed in the present work to the investigation of various processing plasmas.
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