S. Arpiainen et al., Effect of lithium diffusion on the native defects in GaAs studied by positron annihilation spectroscopy, PHYSICA B, 274, 1999, pp. 701-704
The influence of Li diffusion on GaAs was studied by means of positron anni
hilation spectroscopy. Positron trapping at both gallium vacancy (V-Ga) and
antisite (Ga-As) defects were found to increase after the in-diffusion, an
d increase further after the out-diffusion of Li. This indicates an increas
e in the concentrations of negative and neutral defects in both phases. Maj
ority of the Ga vacancy and antisite defects is, however, supposed to be fo
rmed already during the in-diffusion phase at 800 degrees C, but to remain
passivated by Li prior to the out-diffusion phase at 400 degrees C. The As
antisite (EL2) and the As vacancy (V-As) defects were not detected after th
e incorporation of Li. All these results can be explained by a simple set o
f defect formation and reduction processes. (C) 1999 Elsevier Science B.V.
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