High resolution imaging of the CdTe/(100)InSb interface: a lattice-matched hetero-epitaxial structure

SUMMARY This paper reviews techniques available for obtaining images which can distinguish the two components in lattice-matched, hetero-epitaxial structures. From series of computer simulations it is shown that in the case of CdTe/(100)InSb the usual criteria for ‘good’ high resolution imaging (i.e. thin crystal, Scherzer focus) do not give images which differentiate the two materials. Conditions which do show different contrast features for both CdTe and InSb are found; under these conditions images are obtained which reveal the interfacial structure clearly, and show it to be essentially flat, and free of defects within the regions examined. Prospects for obtaining true ‘atomic’ images using a new 400 kV HREM are outlined.