Electrophysical characteristics of accidental-doping defects in epitaxial n-type gallium arsenide

The Hall effect and electrical conductivity in the temperature range 10–900?K were used to investigate the electrophysical parameters of accidental defects in epitaxial n-type gallium arsenide. The experimentally determined parameters of the shallow donor impurity found in n-type gallium arsenide are similar to those of silicon. The anomalous behavior of the Hall constant at T>500?K can be accounted for by the hypothesis of thermal conversion of oxygen-containing defects (complexes of intrinsic and extrinsic defects) from a neutral state to an electrically active state. The kinetic parameters of this process are evaluated. The deviation of the experimental behavior of the electron mobility at temperature above 500?K can be attributed largely to the nonuniformity of the electrophysical parameters over the thickness of the gallium arsenide films and to the presence of accidental oxygen-containing defects in the investigated material.