+1 (202) 780-3397
Densities of active species in N2 RF and HF afterglows
5th International Conference on Plasam Chemistry and Plasma Processing
November 13-14, 2017 Paris, France
A Ricard, J P Sarrette, Y Wang and Y K Kim
University of Toulouse, France Ajou University, South Korea
Scientific Tracks Abstracts : J Biot Phyt
Abstract:
N2 flowing afterglow emissions have been analyzed by optical emission spectroscopy in tubes of 21 and 18 mm internal diameter connected to RF and HF sources available in Suwon and Toulouse, respectively. The N2 1st pos (580 nm), 2nd pos (316 nm) and N2+ 1st neg (391.4 nm) band system intensities were recorded across the tube diameters from the pink (early) to the late afterglows at pressure 6-8 Torr, total flow rate 0.5-0.6 slm and input power of 100 watt. After calibration of the N atom density by NO titration, the concentrations of N-atoms, O-atoms coming from gas impurities, N2(X, v>13), N2(A) metastable molecules and N2+ ions were determined in N2 afterglows. It is found that N–atom density nearly constant from the pink to the late afterglow. For similar afterglow times, active species densities are higher in HF than in RF: 2 and 0.4x1015 cm-3, respectively. Anatase nanocrystals and ALD (Atomic Layer Deposition) TiO2 samples were exposed to the RF and HF afterglows at room temperature. XPS analysis of samples submitted to the RF afterglow has shown that the best N/Ti coverage: 0.24 was obtained in the N2 late afterglow where the N atoms are the most populated active species. In the HF late afterglow, the N/Ti coverage was limited to 0.04 in spite of higher N-atom density: (1-2)x1015 cm-3. Such results are explained by higher O-atom impurity in HF: 2x1013 cm-3 in comparison to 8x1011 cm-3 in RF. Then, the N/O ratios in the RF and HF afterglows were respectively (0.5-1)x102 and 5x102 with the same variations as found for the N/Ti coverages.
Biography:
A Ricard worked at Ecole Polytechnique as a physicist from (1960-1962). Then form 1962-1964 he worked at Institut Optique as Engineer, from 19641967 worked at Sud-Aviation as Engineer, from 1967- 2007 he worked as a researcher in CNRS. He received his PhD in 1971 form University of Toulouse. He is expertise in the field of plasma spectroscopy, kinetics of plasma excited species, applications to surface treatments.
PDF HTML