ORDERING IN INGAAS INALAS LAYERS

The structure of InGaAs/InAlAs layers lattice matched to an InP substr ate, grown on either (100) or on (11O) with a 4 degrees tilt toward [1 1 $$($) over bar 1] at 500 and 300 degrees C has been investigated by transmission electron microscopy. High perfection resulted for the lay ers grown on [001] oriented substrates whereas growth on the near [110 ] substrates resulted in compositional nonuniformities, macrosteps for mation, and ordering of the group III elements. This difference in str uctural perfection between the two sets of samples was also reflected in differences in electrical properties.