  We demonstrate an atomic force microscopy based method for estimation of
defect density by identification of threading dislocations on a non-flat
surface resulting from metamorphic growth. The discussed technique can be
applied as an everyday evaluation tool for the quality of epitaxial structures
and allow for cost reduction, as it lessens the amount of the transmission
electron microscopy analysis required at the early stages of projects.
Metamorphic structures with low surface defectivities (below 106) were
developed successfully with the application of the technique, proving its
usefulness in process optimisation.
