Energy distributions of Ga~+ and In~+ secondary ions sputtered from A~ⅢB~Ⅴ compound semiconductors by noble gas ions: Mass-dependence of the high-energy yield on the second component (P, As, Sb) of the compounds

摘要

Experimental and simulated energy distributions of Ga~+ and In~+ secondary ions produced by 4 keV Ne~+, Ar~+ and Kr~+ bombardment of the A~ⅢB~Ⅴ semiconductors (GaP, GaAs, GaSb, InP, InAs and InSb) are reported. The measurements were carried out for a wide range of initial energy (up to 1000 eV) in a small solid angle along the surface normal, without applying electric field to extract the ions into the mass-energy analyser. It is shown that the energy spectra are complex, with evident high-energy hump, whose relative intensity increases with the mass of the second component (P, As, Sb) of the compound. The Sigmund―Thompson distribution cannot fit reliably these data, and a satisfactory approximation of the measured spectra was obtained with a sum of two decaying exponential functions to describe the contribution of both, the isotropic linear collision cascades and the outward knock-on atoms. The experimental results are compared with simulations based on the MARLOWE computer code.