Effect of Substrate Misorientation on Heteroepitaxy with Large Lattice Mismatch: Ag/Si(111)

Abstract

AbstractEpitaxial films of Ag(111) were grown by Molecular Beam Epitaxy (MBE) on small angle misoriented Si(111) substrates. The surface normal was tilted 0 to 6° away from the Si(111) axis toward the [112] direction. The structure of the films was analyzed by x-ray diffraction and MeV He+ ion channeling. Despite a large lattice mismatch, good quality epitaxial films, 600–1200 Å thick, were grown on the misoriented Si substrates. Interestingly, the angle between the Si(111) axis of the substrate and the Ag(111) axis of the film (the misalignment angle) is not zero. In contrast to the perfect alignment on a flat substrate, the Ag(111) axis is tilted away from the Si(111) axis toward the surface normal. Axial MeV He+ ion channeling shows the misalignment angle (up to .6°) increases with substrate misorientation angle (~1/10 substrate misorientation angle).