Defect transformations at low temperatures in ion-implanted AlxGa1-xAs ternary compounds were studied (where x ranged from 0 to 1). The samples were implanted with 150keV N or 200keV Ar ions to various doses, at 18 to 77K, and in situ Rutherford back-scattering/channeling measurements were performed as a function of temperature. A marked recovery stage, which was attributed to defect mobility in the Ga(Al) sub-lattice was detected near to 280K. At x-values of above 0.5, this stage was largely suppressed. Instead, continuous damage recovery at low temperature was observed. It was noted that defect recombination could also be produced during prolonged storage at the implantation temperature. For AlAs, the 280K stage disappeared completely and only limited defect recovery at low temperatures was found. Upon N- or Ar-ion bombardment, a sharp crystalline-to-amorphous transition appeared after an incubation period. The amorphization dose increased with increasing x-value, and was a factor-of-10 higher for x = 0.96 than that for x = 0. A further increase in dose, by a factor of 15, was required to amorphize AlAs.

Compositional Dependence of Defect Mobility and Damage Buildup in AlxGa1-xAs. A.Stonert, A.Turos, L.Nowicki, B.Breeger, E.Wendler, W.Wesch: Nuclear Instruments and Methods in Physics Research B, 2001, 175-177, 219-23