Quantitative measurements of atomic oxygen using hybrid fs/ps CARS
ORAL
Abstract
Atomic radicals play a key role in plasma-enhanced deposition and etching of materials in semiconductor processing. However, there are few alternatives to two-photon laser-induced fluorescence for quantifying atomic species in situ. Here, we present hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps CARS) measurements of atomic oxygen using Raman transitions between ground state spin-orbit split energy levels. We demonstrate localized 1-D spatial distributions of rotational temperature and atomic oxygen profiles of nanosecond-pulsed pin-to-pin discharges in O2/Ar mixtures. The use of hybrid fs/ps CARS enables the measurement of the Raman coherence decay times and associated linewidths of atomic oxygen. A strategy to enhance the relative signal-to-noise ratio of atomic oxygen by leveraging molecular oxygen electronic coherence beating will be discussed.
*This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under contract number DE-NA0003525. This research used resources of the Low Temperature Plasma Research Facility at Sandia National Laboratories, which is a collaborative research facility supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences. The views expressed in this paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government
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Presenters
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Timothy Chen
- Applied Materials, Inc.