Selective Sputtering of Impurity Hydrogen Atoms from a GaN(0001) Surface by Slow Multicharged Ion Impact

Abstract

Time-of-flight secondary ion mass spectrometry was conducted for slow multicharged Arq+ (q = 4, 6, or 8) impact on a GaN(0001) surface. Selective sputtering of protons from impurities was demonstrated. The relative intensity of protons increased with an increase in the charge state q, and it reached 92% in the case of Ar8+ incidence with scattering Ar+. The width of the proton spectrum measured in coincidence with scattering Ar+ ions was almost equal to that of Ar atoms in Ar8+ impacts. These facts suggest that the potential sputtering rather than the kinetic sputtering of impurities was dominant in the Ar8+ impact.