Ionization mechanism of H+ sputtered from hydrogenated silicon

The emission of H+ sputtered from hydrogenated amorphous silicon has been studied for 3- to 30-keV noble-gas-ion bombardment. The results suggest that excited silicon atoms can be emitted as (Si2pH)+ molecules. Auger deexcitation in vacuum results in (SiH)2+ which disintegrates into Si+ and H+ with a corresponding gain in kinetic energy due to Coulomb explosion. Direct emission of H+ is important only at H+ energies > 30 eV or at bombardment energies <3 keV. © 1979 The American Physical Society.