Oxygen behavior in liquid phase epitaxial GaAs

The oxygen activity in the gallium solvent was controlled and measured by an electrochemical method, during the liquid phase epitaxy of GaAs. This technique, in combination with SIMS analysis of GaAs grown from O¹⁸ saturated melts, was used to determine the oxygen distribution coefficient at 840°C. In this temperature region, the low solubility of oxygen in liquid gallium combined with a distribution coefficient ? 10^?3 leads to maximum oxygen levels in the ? 10¹⁶ cm^?3 range. The behavior of oxygen in three layers, with significant differences in oxygen concentration, was evaluated by photoluminescence and deep level transient spectroscopy, and no direct relationship was observed between the energy levels in the PL or DLTS spectra and the oxygen concentration in epitaxial GaAs.