A comparison of the amorphization induced in Al<i>x</i>Ga1−<i>x</i>As and GaAs by heavy-ion irradiation

Abstract

The response of AlxGa1−xAs/GaAs samples to bombardment with heavy ions (50 keV Kr+, 50 keV and 1.5 MeV Xe+) was studied as a function of ion dose at temperatures of 30 and 300 K using transmission electron microscopy. Samples with x=0.2 and 0.85 were used. Under all irradiation temperature and ion combinations, the AlGaAs was more resistant to amorphization than GaAs. The resistance increased with increasing Al content and decreased with decreasing irradiation temperature. This difference in the response may be attributed to differences either in the mechanisms by which a region is rendered amorphous (i.e., by direct impact amorphization or by the buildup of point defects) or to differences in the inherent stability (recrystallization temperature and rate) of individual amorphous zones in AlGaAs and GaAs.