Damage production in semiconductor materials by a focused Ga+ ion beam

The semiconductor materials Si, SiC, GaP, InP, GaAs, and InAs were irradiat ed at normal incidence and room temperature with a focused Ga+ ion beam in order to investigate the damage production at high current densities on the order of some A cm(-2). The samples were irradiated with ion fluences betw een 2x10(13) and 2x10(15) Ga+ cm(-2) at an ion energy of 50 keV. The critic al ion fluences for amorphization were determined by Rutherford backscatter ing spectrometry and by Raman spectroscopy. It was found that for SiC, GaP, and InP the number of displacements per atom necessary for amorphization i s about the same one as that required for irradiation at low current densit ies, but in the cases of Si, GaAs, and InAs the high and low current densit y results differ remarkably. The reason for the different behavior of these materials is discussed. (C) 2000 American Institute of Physics. [S0021-897 9(00)00823-9].