Self-compensated standing wave probe for characterization of radio-frequency plasmas

Ta-Lun Sung; Shosaku Matsumura; Kungen Teii; Shinriki Teii

doi:10.1063/1.4884025

Self-compensated standing wave probe for characterization of radio-frequency plasmas

Rev Sci Instrum. 2014 Jun;85(6):063507. doi: 10.1063/1.4884025.

Authors

Ta-Lun Sung¹, Shosaku Matsumura², Kungen Teii³, Shinriki Teii¹

Affiliations

¹ Department of Chemical and Materials Engineering, Lunghwa University of Science and Technology, Taoyuan 33306, Taiwan.
² Department of Electrical and Electronic Engineering, Tokyo City University, Tokyo 158-8557, Japan.
³ Department of Applied Science for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580, Japan.

PMID: 24985819
DOI: 10.1063/1.4884025

Abstract

A simple self-compensated Langmuir probe using the character of a standing wave is developed for characterization of radio-frequency (RF) discharge plasmas. This probe is based on a concept that the interference of RF field is eliminated at the node of a standing wave which exists ideally at one-fourth of the RF wavelength (λ/4) away from the probe tip in the plasma. The fluctuation of plasma space potential is suppressed as confirmed by comparison with a non-compensated probe and a self-compensated probe using an inductor-capacitor (LC) resonant circuit. The plasma parameters obtained with the standing wave probe are in agreement with those with the LC resonant probe within discrepancy of 15% indicating high reliability of the results.