Defects in LEC-grown Indium Phosphide Crystals Doped with Tin

Crystalline defects in Sn-doped LEC indium phosphide have been revealed by chemical etching and analyzed by TEM. Grown-in dislocations, various kinds of defect clusters and colonies of microdefects were found. The symmetrical defect clusters are shown to equate mostly with larger dislocation loops exhibiting shear components and/or other dislocation arrangements generated by a stress source which is positioned in the centre of the dislocation cluster. Those centres are often formed by a plate-like agglomeration composited of tiny inclusions and very small faulted dislocation loops. Such planarly arranged accumulations of microdefects lie on {111} planes. The direct vicinity of single threading grown-in dislocations is always enriched with tiny perfect dislocation loops and precipitates. Additionally, very large isolated interstitial-type perfect dislocation loops with b = a₀/2 〈110〉 have been found by TEM experiments. Mostly, the {110} habit plane of such loops is decorated with an high number of small dislocation loops and precipitates as a consequence of dislocation climb.