2000 Fiscal Year Final Research Report Summary
Development of High- speed Infrared Ellipsometer for Industrial Use
| Project/Area Number |
10650420
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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 |
Measurement engineering
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| Research Institution | Tsuruoka National College of Technology |
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Principal Investigator |
MIYAZAKI Takao Tsuruoka National College of Technology Control & Information Engineering, Professor, 制御情報工学科, 教授 (80280337)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Infrared / Ellipsometry / Thin-film, thermopile / Pyro-electric sensor / CO_2 laser / Polarization Analysis / Infrared sensor / Film thickness measurement |
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| Research Abstract |
It is crucial to use an infrared sensor with, the characteristics of good linearity, fast response to develop the fast infrared ellipsometer for industrial use. A pyro-electric sensor is investigated at first to verify the possibility for an infrared sensor of the fast infrared ellipsometer. It is demonstrated, however, that a pyro-electric sensor is inappropriate for the purpose because they begin to show the hysterisis if infrared source (CO_2 laser) power exceed 10mW, resulting poor repeatability and accuracy. Next, the thin-film thermopile sensor manufactured by Fortech Inc. Germany is investigated.
This sensor shows good linearity from mW to W levels and has fast response time of order of 1micro-second simultaneously. It needs no cooling apparatus and inexpensive compared to HgCdTe sensor. The prototype of 3 channel fast infrared ellipsometer with the use of three thin-film thermopile sensors is developed. So far following facts are confirmed through the study and experiment carried by the prototype of the ellipsometer.
1) Instability of polarization state and high frequency output noise of the CO_2 laser used as an infrared source is experimentally demonstrated.
2) This ellipsometer can be applied to diffusive surfaces which are hard for a visible ellipsometer.
3) Each ellipsometric parameter, phase difference Δ and angle of amplitude ratio Ψ, has almost same value, where Δ nearly equals to π and Ψ to π/4, regardless of kind of metals.
This information can be utilized to improve sensitivity or minimize errors of the ellipsometer.
4) Evaluation of 3 channel fast infrared ellipsometer has not been completed and the investigations are planned to be continued
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