Striations in a radio frequency planar inductively coupled plasma
- Univ. of Wisconsin, Madison, WI (United States)
Cylindrical planar radio frequency (RF) inductively coupled plasmas (ICP) as used in commercial reactors for materials processing are generally considered both experimentally and theoretically as two-dimensional (2-D) (r-z) systems, with symmetry in the azimuthal coordinate. Here, photographic evidence is presented for azimuthal structure in cylindrical radio frequency (RF) planar inductively coupled plasmas. Observations made in a high aspect ratio chamber (antenna radius large compared to height of plasma volume) show azimuthal striations (periodic modulations in emitted light intensity) in an argon discharge. These striations, reported here for the first time, have serious implications for discharge uniformity under some conditions (discharge shown at 300 W RF power, 85 mtorr). A comparison to positive column striations in dc glow discharges shows some similarities, although a complete explanation will require consideration of RF effects.
- OSTI ID:
- 244947
- Journal Information:
- IEEE Transactions on Plasma Science, Journal Name: IEEE Transactions on Plasma Science Journal Issue: 1 Vol. 24; ISSN ITPSBD; ISSN 0093-3813
- Country of Publication:
- United States
- Language:
- English
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