Spatially and temporally resolved absolute O‐atom concentrations in etching plasmas
A. Tserepi, T. Miller
Jan 15, 1995
Citations
49
Citations
Journal
Journal of Applied Physics
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Semantic Scholar
Key Takeaway Key Takeaway: Two-photon-allowed laser-induced fluorescence reveals uniform oxygen atom distribution in etching plasmas, with a time-dependent production rate and dependence on discharge pressure, power, and gas composition.
Abstract
The detection of atomic O by two‐photon‐allowed laser‐induced fluorescence is implemented to obtain the spatial distribution and the temporal evolution of oxygen atoms in a 10 MHz parallel‐plate rf discharge. Absolute concentrations are determined via a titration technique for intensities typically found in 20–100 W, 0.1–3 Torr O2 discharges, and are in the range 4–30×1014 atoms/cm3. The spatial O distribution after initial turn on of the discharge is rather uniform, indicative of a uniform production of O atoms throughout the interelectrode space. Furthermore, the decay of the O concentration reveals information about the reaction of O atoms with surface materials in the plasma environment, while the rise of the population indicates a time‐dependent production rate. The dependence of the O‐concentration rise and decay rates on discharge pressure, power, and gas composition is explored.