Structural properties of compressive and tensile strained InGaAs/InP heterostructures

Different extended defects affect the InGaAs alloy when tensile or compressively stressed. In tensile stressed samples, grooves, planar defects and cracks are present in addition to the interfacial network of misfit dislocations. Here we report a systematic study of the structural properties of MOVPE grown InGaAs/InP tensile and compressively strained epilayers carried out by means of by TEM CL, RBS-Channeling, X-ray diffraction and SFM techniques. The correlation between the observed defects and the mechanisms of strain relaxation in both cases is discussed.