Liquid phase epitaxial layers of InxGa1−xAsyP1−y grown lattice matched to InP〈001〉 substrates, in the concentration range 0.53⩽x⩽0.88, have been studied by transmission electron microscopy. For the usual growth temperatures, solid instability was predicted for compositions in the range 0.55≲x≲0.75. Indeed a quasiperiodic variation of a strain contrast, though very light in some cases, is always observed in the 〈100〉 and 〈010〉 directions in that composition range, and never outside. The pseudoperiodicity is of the order of 1000 Å. Local concentration measurements have been performed on one sample using a scanning transmission electron microscope. They show that the strain contrast, quite strong in that sample, is related to a concentration modulation. The measured variations on x and y are as high as 0.1, and they keep the ratio x/y constant, which is consistent with phase separation observed on nucleated InxGa1−xAsyP1−y.

Damage evolution and dopant distribution during nanosecond laser thermal annealing of ion implanted silicon have been investigated by means of transmission electron microscopy, secondary ion mass spectrometry, and atom probe tomography. Different melting front positions were realized and studied: nonmelt, partial melt, and full melt with respect to the as-implanted dopant profile. In both boron and silicon implanted silicon samples, the most stable form among the observed defects is that of dislocation loops lying close to (001) and with Burgers vector parallel to the [001] direction, instead of conventional {111} dislocation loops or {311} rod-like defects, which are known to be more energetically favorable and are typically observed in ion implanted silicon. The observed results are explained in terms of a possible modification of the defect formation energy induced by the compressive stress developed in the nonmelted regions during laser annealing.

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It is now well admitted that most quaternary III–V compounds show unstable regions in the temperature range commonly used in epitaxy. For instance, according to these authors, the InGaAsP alloy, lattice matched to InP and with emitting wavelength 1.3 μm should be unstable at temperatures below 700 °C. Liquid phase epitaxy, however, is commonly performed down to 600 °C. As this growth technique occurs close to thermodynamical equilibrium, such growth should not take place. It was clearly demonstrated that the substrate stabilizing effect is responsible for this paradoxical behavior. Another LPE substrate effect pointed out by Stringfellow is known as the ‘‘pulling effect.’’ Results will be presented showing the connection between these effects in the system InGaAsP/InP and particularly InGaAs/InP. ‘‘Stabilized’’ GaAsSb was also successfully epitaxially grown on InP, in the immiscibility region, from the liquid phase. Microscopic compositional periodical modulations are observed in standard InGaAsP epilayers, if growths are performed below a critical temperature. This phenomena, also related to solid instability, can be interpreted in terms of liquid–solid interfacial spinodal decomposition.

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