電漿製程中電漿密度之量測－傳輸線式微波干涉儀

Plasma Density Measurement in Plasma Process-A Transmission-Line Microwave Interferometer

10.29808/JVSROC.201203.0003

謝政宏(C. H. Hsieh)；張家豪(C. H. Chang)；鄭景元(J. Y. Jeng)；柳克強(K. C. Leou)

電漿製程 ； 電漿密度 ； 微波干涉儀 ； Plasma Processing ； Plasma Density ； Microwave Interferometer

真空科技

25卷1期（2012 / 03 / 01）

24 - 30

繁體中文

在本文中，我們介紹一種電漿製程中的電漿密度量測方式：傳輸線式微波干涉儀。此干涉儀的基本原理與傳統微波干涉儀的原理幾乎相同，差別只在於傳輸線式微波干涉儀的感測（Sensing）微波乃沿著一傳輸線結構傳遞，而非在真空中傳遞。本文中的傳輸線是以同軸介質波導的結構來傳遞2.4GHz的微波，此量測系統中的微波模組包含一微波源以及用以分析傳輸線上微波相位的相位偵檢器。此干涉儀系統的量測結果不僅即時，更可完整反映電漿源的狀態。此外，傳輸線式微波干涉儀的電漿密度量測與Langmuir探針之結果比較，兩者所得的趨勢一致。

In the article, we introduce both the theoretical analysis and proof-of-principle experimental results of a novel transmission-line microwave interferometer (TLMI) for measurements of plasma density. The principle of this technique is the same as conventional microwave interferometers except that the sensing microwave propagates along a transmission-line structure. For this study, the transmission-line is a circular coaxial dielectric waveguide operated at 2.4 GHz. A microwave module of the TLMI system, consisting of a microwave source and a phase detector, has also been developed for detecting the phase of the microwave propagating through the transmission-line. The measurement of the TLMI system shows a real-time and complete response to the plasma source. The result of plasma density measured by the interferometer is well consistent with that from a Langmuir probe.