16 April 1993 Electrical measurements for monitoring and control of rf plasma processing
Author Affiliations +
Proceedings Volume 1803, Advanced Techniques for Integrated Circuit Processing II; (1993) https://doi.org/10.1117/12.142926
Event: Microelectronic Processing '92, 1992, San Jose, CA, United States
We have investigated the possibility of using current and voltage measurements for real-time monitoring and control of radio-frequency discharges. Specifically, we have equipped a gaseous electronics conference (GEC) rf reference cell with a computer-controlled measurement system that samples the voltage and current waveforms at the cell power input and Fourier analyzes these waveforms to obtain the amplitude and phase of their fundamental and harmonic components. The system accounts for errors introduced by the stray impedance of the cell, yielding corrected values that more accurately reflect the values of voltage and current at electrode surfaces in contact with the plasma. These corrected values are monitored to reveal changes in fundamental plasma parameters such as sheath voltages, sheath fields, and sheath (dark space) thicknesses. Furthermore, the corrected values serve as better control parameters than the raw values of voltage, current or power, measured externally. The time required for the acquisition and analysis of a pair of current and voltage waveforms is approximately one second, making these measurements suitable for real-time sensing and control applications.
© (1993) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mark A. Sobolewski, Mark A. Sobolewski, James R. Whetstone, James R. Whetstone, } "Electrical measurements for monitoring and control of rf plasma processing", Proc. SPIE 1803, Advanced Techniques for Integrated Circuit Processing II, (16 April 1993); doi: 10.1117/12.142926; https://doi.org/10.1117/12.142926

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