Misorientation, Inhomogeneous Lattice Distortion and Strain of InP Grown on Si by Metalorganic Chemical Vapor Deposition

Inhomogeneous lattice deformation, misorientation and strain of InP epitaxial layers grown on Si substrates by an MOCVD two-step method are obtained from high resolution X-ray diffraction measurements. The InP films were grown simultaneously on Si (001) and on Si (001) misoriented 3° towards [110]. In the latter, we observe a tilt of the InP [001] axis of 0.1° respect to the Si [001] in the direction of the substrate normal, and the coexistence of weakly and strongly strained domains. The misorientation of the substrate surface from (001) planes results in an uneven distribution of 60° dislocations which gives rise to an extra component of the Burgers vectors perpendicular to the interface causing the observed tilt. The local stress perpendicular to the interface, thus generated explains the existence of the strongly strained domains.