International Journal of Physics | Vol. 6, No. 4, April 2015 | pp. 25–32
DOI: 10.46882/2015/IJP/000060
Research Article
Title: Kinetic Modelling of Electron Transport Parameters and Ionization Coefficients in Silane-Hydrogen Plasmas
Names of Authors: D. L. Santos¹, K. N. Gupta²
Authors’ Affiliations: ¹Department of Physics, University of Coimbra, Coimbra, Portugal; ²Department of Physics, Indian Institute of Technology, New Delhi, India
Abstract: Silane-hydrogen (SiH4-H2) gas discharges are widely used in the solar industry to deposit high-quality amorphous silicon thin films for photovoltaic panels. This paper develops a self-consistent kinetic model to evaluate electron transport parameters and calculate ionization coefficients in low-pressure silane-hydrogen mixtures. We solved the electron Boltzmann equation using a multi-term spherical harmonic expansion framework across a wide reduced electric field range (E/N) from 5.0 Td to 600.0 Td. The cross-section dataset included elastic momentum transfer, rotational, vibrational excitation, dissociative attachment, and direct impact ionization processes. Our modeling results show that adding small fractions of silane (from 2.0% to 10.0% by volume) drastically distorts the electron energy distribution function. At E/N = 50.0 Td, the total dissociation rate coefficient increases by an order of magnitude due to the low threshold energy of silane vibrational modes. The calculated electron drift velocities and diffusion coefficients match independent swarm experimental measurements within a tight ±5.0% variance. These kinetic parameters provide essential input data for optimizing industrial plasma-enhanced chemical vapor deposition reactors.
Keywords: Silane plasmas; Boltzmann equation; electron transport; ionization coefficient; chemical vapor deposition; cross-section
Manuscript Timeline: Received: January 04, 2015; Revised: February 18, 2015; Accepted: March 05, 2015; Published: April 10, 2015
Citation: Santos, D. L., & Gupta, K. N. (2015). Kinetic Modelling of Electron Transport Parameters and Ionization Coefficients in Silane-Hydrogen Plasmas. International Journal of Physics, 6(4), 25–32.
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