Design and Simulation of Langmuir Probe in Plasma Diagnostic System

• Main Authors: Wen-Chieh Li, 李文傑
• Other Authors: Bing-Hung Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/60557035098846968335

碩士 === 國立東華大學 === 電機工程學系 === 90 === The electrical probe is called Langmuir probe, which is immersed in a plasma system to get important plasma information. Generally, the probe is connected by an adjustable voltage source (-50~+50 DC). The measured current collected by the probe is a function of the applied voltage. This resulting relationship between the probe current and probe voltage is the current voltage characteristic（I-V characteristic）. From the I-V characteristic we can derive the plasma parameter such as：plasma potential、floating potential、plasma density、electron temperatureand electron energy distribution function（EEDF）etc. The purpose of this study is to establish a plasma measurement system using electrical probe technique. Probe technique has been applied in DC plasma measurement, but it is a suffering to directly use in RF plasma because of the RF interference which will distort the I-V characteristic. In this research, we design the probe measurement system with wider frequency compatibility and present the simulation results with different plasma conditions to verify RF interference has been diminished in I-V characteristic.