Transport Coefficients in Mixtures Ar/H2

Ž. Nikitović and V. Stojanović Institute of Physics, University of Belgrade, POB 68, 11080 Belgrade, Serbia

Received: August 23, 2012; In final form: November 23, 2012

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In this work we present electron transport coefficients for electrons in Ar/H2 mixtures for the conditions used in plasma assisted technologies for semiconductor production i.e. in moderate to very high reduced electric field E/N (E - electric field, N - gas density). We used a two term numerical solution of the Boltzmann equation at the lowest E/N and mean energies and also Monte Carlo simulation technique at moderate and high E/N. We show that a good agreement with experimental data exists for low and moderate E/N and that based on the tests for pure H2 and Ar we can model properly the high E/N development. Results were obtained for abundances of H2 from 1% to 50%. Such data are required to test the sets of cross-section data which are necessary in kinetic models for this mixture and also to produce transport coefficients for fluid models. Hydrogen is used for etching of organic compounds, most importantly low k dielectrics, at the same time argon as a buffer gas is added to control the mean energy and distribution function. Besides, operation at high E/N allows the generation of fast neutrals for charging free etching on nanometer scales.

DOI: 10.12693/APhysPolA.123.73 PACS numbers: 51.10.+y, 52.20.Hv, 52.65.Pp, 52.77.-j