Plasma density information measuring method, probe used for measuring plasma density information, and plasma density information measuring apparatus
First Claim
1. A plasma density information measuring method, comprising the steps of:
- supplying high-frequency power to plasma;
measuring a physical amount indicative of reflection or absorption state of said high-frequency power by plasma load; and
obtaining a plasma absorption frequency which is a frequency in which strong absorption of high frequency power occurs attributed to the plasma density based on the result of measurement of the physical amount as above.
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Abstract
A plasma density information measuring method capable of easily measuring the plasma density information over the long term, a probe for measuring the plasma density information, and a plasma density information measuring apparatus are disclosed. A measuring probe is set such that a tip end of a glass tube of the measuring probe is brought into contact with plasma PM to be measured. High-frequency power sent through a coaxial cable is supplied to the plasma PM from a loop antenna through a wall of the tube, and reflection power of the high-frequency power is received by the loop antenna to obtain a counter frequency variation of reflection coefficient of the high-frequency power. In the obtained reflection coefficient, a portion thereof in which the reflection coefficient is largely reduced is a peak at which strong absorption of high-frequency power is caused due to the plasma density. The plasma density can be obtained from the plasma absorption frequency.
111 Citations
7 Claims
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1. A plasma density information measuring method, comprising the steps of:
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supplying high-frequency power to plasma;
measuring a physical amount indicative of reflection or absorption state of said high-frequency power by plasma load; and
obtaining a plasma absorption frequency which is a frequency in which strong absorption of high frequency power occurs attributed to the plasma density based on the result of measurement of the physical amount as above. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification
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- Resources
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Current AssigneeNissin Company Limited, The President of Nagoya University
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Original AssigneeNissin Company Limited, The President of Nagoya University
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InventorsSugai, Hideo, Toyoda, Naoki, Takasuga, Seiichi
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Primary Examiner(s)Wong, Don
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Assistant Examiner(s)Vu, Jimmy T.
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Application NumberUS09/357,773Time in Patent Office909 DaysField of Search315/111.21, 315/111.51, 315/111.41, 324/576, 156/345US Class Current315/111.21CPC Class CodesH01J 37/32082 Radio frequency generated d...H01J 37/32935 Monitoring and controlling ...H05H 1/0062 by using microwaves
