AVS 47th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS2-ThM

Paper PS2-ThM8
Electron Temperature and Ion Energy Measurements with A High-resolution, Sub-micron, Retarding Field Analyzer

Thursday, October 5, 2000, 10:40 am, Room 311

Session: Plasma Diagnostics II
Presenter: M.J. Sowa, Sandia National Laboratories
Authors: M.J. Sowa, Sandia National Laboratories
M.G. Blain, Sandia National Laboratories
R.L. Jarecki, Sandia National Laboratories
J.E. Stevens, Sandia National Laboratories
Correspondent: Click to Email
A silicon wafer-based, submicron, high-resolution, retarding field analyzer (RFA)@footnote 1@ was used to measure ion energy and infer electron temperature (Te) in an inductively coupled plasma. RFA ion energy measurements are expected to have a resolution of < 0.1 eV based on simulations. By monitoring the flux of ions to the collector of the RFA while allowing the shield to float, we are able to measure the local difference between the plasma and floating potentials. From this difference, the electron temperature can be calculated directly from sheath theory. Experimental conditions include 10, 20, and 40 mTorr Ar at 100, 200, and 300 W of plasma source power at axial positions of 42-217 mm from the source dielectric window. RFA Te values were compared to those obtained with single and double probes. Excellent agreement was observed between the single probe and RFA over all conditions. Double probe measurements matched the other measurement techniques at 20 and 40 mTorr, and gave 5-30% higher Te values at 10 mTorr. The ion energy spreads measured with the RFA are close to Gaussian with standard deviations from 1.8-2.2 eV. The ion energy spread increased weakly with pressure but showed little dependence on the position or the measured Te value, which ranged from 1.3 - 2.7 eV.@footnote 2@ @FootnoteText@ @footnote 1@ M.G. Blain, J.E. Stevens, J.R. Woodworth, Appl. Phys. Lett., v.75, n.25, p.3923, 1999. @footnote 2@ Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000.