Strain relief by long line defects in tensile GaxIn1-xP layers grown on InP substrates

Fully strained layers of GaInP on InP significantly thicker than the theore tical critical thickness were grown by metalorganic molecular beam epitaxy. The excess strain energy of these layers is most probably accommodated by long line defects observed by atomic force microscopy. The thickness at whi ch the long line defects appear is about four times the Matthews and Blakes lee critical thickness [J. W. Matthews and A. E. Blakeslee, J. Cryst. Growt h 27, 118 (1974)]. Partial relaxation is measured by x-ray at about 14 time s the theoretical critical thickness. (C) 2001 American Institute of Physic s.