Time-resolved plasma parameter measurements in a low-frequency rf glow discharge

A new approach to the use of Langmuir probes in a rf driven plasma is presented. The periodic nature of the rf is utilized to overcome the distortion of the probe characteristics caused by averaging over many rf cycles. Time-resolved measurements of the electron density, electron temperature, plasma potential, and floating potential in the negative portion of the rf cycle are obtained. The technique is used to characterize a low-pressure 100-kHz capacitively coupled rf argon discharge. The measured electron temperature is found to be approximately 0.5 eV.