Negative ion formation in the scattering of CF3+ from graphite

The scattering of CF3+ from highly oriented pyrolytic graphite results in t he formation of CF3-. Comparison is made with CF3+ scattering from a metal and from an insulator surface, which do not yield negative molecular ions. The outcome of the charge transfer processes that occur as CF3+ approaches a surface is critically dependent on the electronic properties of that surf ace. The ability to produce a stable negative ion close to a surface may be an important factor in the etching efficiency of the CF3 molecule. (C) 200 0 American Institute of Physics. [S0003-6951(00)05534-0].