Defect transformations at low temperatures in ion implanted AlxGa1-xAs (0 l
ess than or equal to x less than or equal to 1) ternary compounds were stud
ied. Experiments consisted of ion implantation with 150 keV N or 200 keV Ar
ions with different doses at temperatures between 18 and 77 K, and in situ
RBS/channeling measurements at selected temperatures. An important recover
y stage attributed to the defect mobility in the Ga(Al) sublattice was reve
aled near 280 K. For x > 0.5 this stage was largely suppressed. Instead, a
continuous damage recovery at low temperatures was observed. It was noticed
that defect recombination can also be produced upon prolonged storage at t
he implantation temperature. For AlAs (x = 1) the 280 K stage disappeared c
ompletely and only a small defect recovery at low temperatures was noticed.
Upon N- or Ar-ion bombardment, after an incubation period, a sharp crystal
line-to-amorphous transition appeared. The amorphization dose increases wit
h increasing x and is a factor of 10 higher for x = 0.96 than that for x =
0. A further increase of the dose by a factor of 15 was required to amorphi
ze AlAs (x = 1). (C) 2001 Elsevier Science B.V. All rights reserved.