CHARACTERIZATION OF LOW-TEMPERATURE ALXGA1-XAS LATTICE PROPERTIES USING HIGH-RESOLUTION X-RAY-DIFFRACTION

Using high resolution x-ray diffraction techniques, we have studied the lattice parameter behavior of low-temperature (LT) AlxGa 1-xAs as a function of annealing temperature and aluminum content. Similar to LT GaAs, the as-grown LT AlxGa1-xAs layers exhibit a dilated lattice constant which, upon annealing, contracts to that of "normal" material. The onset of this contraction in LT Al 0.3Ga0.7As, however, is found to occur at an annealing temperature nearly 100 °C higher than that required for LT GaAs. In addition, the relative lattice expansion in the as-grown LT layer is found to be a decreasing function of Al content, ranging from 0.099% for LT GaAs to 0.059% for LT Al0.3Ga0.7As. This is attributed to lower than expected As incorporation in the LT AlxGa1-xAs during growth. © 1995 American Institute of Physics.