X-ray crystal diffractometry has been used to assess the crystal quality of InGaAsP/InP single heterostructures grown by the liquid phase epitaxy. Diffraction profiles have been obtained in the parallel non-dispersive configuration, using Cu k?I radiation, 004 symmetric reflection and a perfect InP crystal as monochromator. Several structures, with different lattice mismatches, ranging from positive to negative values, have been investigated. The epilayer Bragg peak has been found as narrow as theoretically predicted, if thickness effects are taken into account. Pendelloesung fringes have observed at the low angle side of the peak, allowing the epilayer thickness to be measured. The sample curvature has been evaluated from the broadening of the substrate Bragg peak and agreement with calculations using elastic theory has been found, when the broadening was sufficiently large. Pendelloesung fringes have been observed on InGaAsP epilayers, demonstrating the high quality of the layers grown by liquid phase epitaxy.
X-ray characterization of LPE InGaAsP/ InP single heterostructures
Bocchi Claudio;Ferrari Claudio;
1988
Abstract
X-ray crystal diffractometry has been used to assess the crystal quality of InGaAsP/InP single heterostructures grown by the liquid phase epitaxy. Diffraction profiles have been obtained in the parallel non-dispersive configuration, using Cu k?I radiation, 004 symmetric reflection and a perfect InP crystal as monochromator. Several structures, with different lattice mismatches, ranging from positive to negative values, have been investigated. The epilayer Bragg peak has been found as narrow as theoretically predicted, if thickness effects are taken into account. Pendelloesung fringes have observed at the low angle side of the peak, allowing the epilayer thickness to be measured. The sample curvature has been evaluated from the broadening of the substrate Bragg peak and agreement with calculations using elastic theory has been found, when the broadening was sufficiently large. Pendelloesung fringes have been observed on InGaAsP epilayers, demonstrating the high quality of the layers grown by liquid phase epitaxy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
