Neutral Heating and Neutral Temperature Measurement in Inductively Coupled Fluorocarbon Discharges
Abstract
Over the past few years, large neutral temperatures ( 600-1500 K) have been measured in inductively coupled discharges. Maintaining these high temperatures requires significant power dissipation into neutral heating, thereby reducing the attainable electron density. Consequently, it becomes very important to characterize the neutral temperature in an inductively coupled plasma before performing a quantitative analysis. This paper will review work characterizing neutral heating phenomena as they pertain to inductively coupled fluorocarbon plasmas, including mechanisms, modeling, and experimental measurements. In addition, our results on optical characterization of neutral temperatures in CF4 and CF4/O2/Ar mixtures will be presented. The disparity between different optical measurement techniques will be examined. Absorption techniques are shown to underpredict neutral temperature due to spatial averaging of temperatures. Temperature measurements through the fit of emission spectra are examined for several species. It is found that the temperature measurements can vary widely depending on the species chosen for measurement. Pressure dependencies of temperature indicate that some species are not well equilibrated with other species in the plasma.
- Publication:
-
APS Annual Gaseous Electronics Meeting Abstracts
- Pub Date:
- October 2002
- Bibcode:
- 2002APS..GECNW1002C