TRANSMISSION ELECTRON-MICROSCOPY OF INP STRANSKI-KRASTANOW ISLANDS BURIED IN GAINP

InP islands in a matrix of GaInP are investigated by transmission elec tron microscopy (TEM). The islands are uniform in size and shape, and are formed through self-organized Stranski-Krastanow growth. The intro duction of a 4 ML intermediate GaP layer eliminates the bimodal distri bution found in films where the InP was grown directly on the GaInP la yer. The achieved island density is around 2 x 10(9) cm(-2), and the b asal plane of the InP islands is around 40 x 50 nm(2). A model is sugg ested for the shape where the islands are in a truncated pyramidal for m, showing {111}, {110}, and {001} facets, with an island height of 10 to 15 nm. A fast and simple specimen preparation method is suggested, based on laser assisted chemical etching.