AVS 57th International Symposium & Exhibition | |
Plasma Science and Technology | Thursday Sessions |
Session PS-ThP |
Session: | Plasma Science and Technology Poster Session |
Presenter: | M.B. Hopkins, Impedans Ltd., Ireland |
Authors: | M.B. Hopkins, Impedans Ltd., Ireland D.M. O'Sullivan, Impedans Ltd., Ireland |
Correspondent: | Click to Email |
Current- voltage probes monitor power parameters, such as the voltage, current and phase angle of an RF power used to generate the plasma (source) or to bias a substrate. A number of commercial systems are available and a key feature is that the sensors work in non-50Ω environment. This allows the sensor be placed either pre-match or post-match and still make accurate measurements.
The most important plasma parameters in a capacitively coupled plasma source or bias configurations are the flux and energy of ions arriving at the substrate. The ion flux is difficult to establish in deposition tools as the plasma often deposits insulating layers, such as in the manufacture of solar panels.
We report on a novel IV sensor, which is placed post-match in series with a capacitively coupled RF biased plasma electrode. The sensor integrates the current into voltage bins. We show that the resulting characteristic represents the real current-voltage (IV) characteristic of the electrode. The measured IV trace is similar to a DC Langmuir probe IV trace and we determine the ion flux to the biased electrode. We compare ion flux measured by the IV probe with the ion flux determined by a retarding field analyzer placed on the electrode.