Negative ion production by surface ionization at aluminum-nitride surfaces

S. Jans, P. Wurz, R. Schletti, and T. Frohlich


In this article, we report on the observation of the formation of negatively
charged ions upon reflection from an aluminum-nitride surface. Positive H2 and
O2 ions are scattered at small angles of incidence off a single-crystal surface.
Charge exchange at the surface yields neutral particles and negative ions in the
reflected particle flux. The negative ion fractions are about 15% and 1% for
oxygen and hydrogen, respectively. The particle reflection probability is only
2%, which is attributed to the roughness of the surface. 

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Journal of Applied Physics, 85 (1), 2587-2592, 2000