Direct Observation of Lattice Arrangement in MBE Grown GaAs–AlGaAs Superlattices

Observation is made of a cross section including the growth direction of an MBE grown GaAs–Al0.28Ga0.72As superlattice structure by a transmission electron microscope with a resolution of 1.4 Å. Relevant atoms are observed to be regularly aligned even across the heterointerface. There is no alloy clustering observed in the ternary alloy layer. Dislocation is clearly observed as a local disorder in lattice alignment for the first time in the MBE grown layer.