RF-Compensated Langmuir Probe Measurements in an IPVD System
Abstract
The experimental apparatus consists of a commercial-scale magnetron with an RF coil between the target and substrate holder. This coil creates a secondary inductive plasma that ionizes a significant portion of the sputter flux en route from target to substrate. In order to understand and predict the ionization of the sputter flux arriving at the substrate, Langmuir probe measurements of this secondary inductive plasma were made under various combinations of powers (magnetron and RF), pressures, and working gas mixtures. The probe apparatus is RF-compensated in order to keep the voltage difference between the probe tip and plasma constant throughout the RF cycle. In order to yield accurate measurements in the dirty depositing environment of the IPVD system, the back of probe tip is recessed in a small ceramic tube, preventing shorting. Further, the potential on the probe tip is kept low except during the data-collecting voltage sweeps in order to continuously clean it and maintain stable electrical characterisitics.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 1998
- Bibcode:
- 1998APS..GECEMP404J