Negative ion production by surface ionization at aluminum-nitride surfaces

Abstract

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.