The effects of rapid thermal annealing upon deep-level defects were studied for epitaxial layers of (Al0.25Ga0.75)0.52In0.48P, doped with Si and Be, and grown onto (100) GaAs substrates via solid-source molecular beam epitaxy. It appeared that rapid thermal annealing significantly affected the net carrier concentrations at temperatures above 700C. Several deep levels were found. It was also found that rapid thermal annealing induced a new deep level, with an activation energy of about 0.5eV, into n-type AlGaInP and another level, with activation energy of 0.75eV, into p-type AlGaInP. Annealing caused a change in the trap parameters of the DX-center. Such behaviour was believed to be due to a change in the defect configuration, or defect clustering. Rapid thermal annealing also increased the concentration of another Si-related defect. An increase in net acceptor concentration, observed for p-type AlGaInP, was related to a decrease in the concentration of a deep level with an activation energy of 1.30eV.

Characterization of Deep Levels in Rapid-Thermal-Annealed AlGaInP. A.Tukiainen, J.Dekker, T.Leinonen, M.Pessa: Materials Science and Engineering B, 2002, 91-92, 389-92