Low-temperature growth and post-growth annealing of GaAsSb

For the first time, low-temperature (LT) growth of GaAs1−ySby with y=0.4 and 0.85, as well as the influence of a post-growth annealing is investigated and compared to LT-GaAs. The wafers were characterized by X-ray diffraction (XRD), Hall, and I-U characteristic measurements. The electrical resistance of the LT-GaAs0.6Sb0.4 wafer increases with increasing annealing temperature, similar to LT-GaAs. XRD measurements of unannealed and 600 °C annealed samples show a lattice constant shift of LT-GaAs0.6Sb0.4 which is more than twice as large as for LT-GaAs. The LT-GaAs0.15Sb0.85 wafer does not exhibit the typical dependencies of a non-stoichiometric layer on an annealing process: no monotonic increase in the resistance and no significant reduction of the lattice constant is observed. Hall measurements on this wafer show a change from n- to p-type conductivity for high annealing temperatures. Hence, there is a certain Sb concentration where the effects observed in LT-GaAs vanish.