Mass and energy distribution of negatively and positively charged small cluster ions sputtered from GaAs(100) by 150keV Ar+ bombardment

Mass and energy distribution of positively and negatively charged small ${\text{Ga}}_x{\text{As}}_y$ cluster ions consisting of up to six atoms sputtered from a GaAs(100) surface after 150 keV Ar⁺ ion bombardment are reported. Positively charged ions contain a larger fraction of Ga atoms while negatively charged ions are rich in As. Measured energy distributions display a maximum at low kinetic energies of a few eV followed by a steep decrease with increasing energy which is more pronounced for larger ions.