Spatial structure of a slot-antenna excited microwave N2-Ar plasma source

The spatial structure of a large-scale, slot-antenna excited (2.45 GHz) surface wave plasma source operating in N-2-Ar mixtures is investigated. A self-consistent theoretical model is developed in the local approximation to investigate the entire spatial structure of the system, including the discharge zone sustained by the field of the TM140 surface mode and the remote plasma zone. Maxwell's equations and the rate balance equations for the most important excited species-vibrationally and electronically excited states, ions, and N(S-4) atoms-and the electron Boltzmann are consistently solved. The pumping of the higher nu th levels of N-2(X (1)Sigma(+)(g),nu) molecules is shown to be very effective and to strongly influence the remote plasma kinetics. Collisions of N-2(X (1)Sigma(+)(g),nu) molecules with N(S-4) atoms are responsible for the increase in the number densities of electrons and electronically excited states N-2(A (3)Sigma(+)(u),B (3)Pi(g),C (3)Pi(u),a' (1)Sigma(-)(u)) in the far remote plasma zone. (C) 2008 American Institute of Physics.