Crystal quality investigation of InGaAs/InP and InGaAlAs/InP single heterostructures grown by molecular-beam epitaxy

X-ray double-crystal diffractometry has been used to assess the crystal quality of InGaAs/InP single heterostructures grown by molecular-beam epitaxy. Experiments performed on step etched samples have indeed shown that the width of the epilayer Bragg peak as a function of the epilayer thickness is in good agreement with the theoretical predictions for perfect crystals. Finally, preliminary observations of InGaAlAs/InP heterostructures have shown very narrow Bragg peaks and this demonstrates the good crystal quality of the quaternary layers.