Epitaxial growth of GaInAsBi thin films on Si (001) substrate using pulsed laser deposition

Abstract

The results of a comprehensive study of growing a Ga1-yInyAs1-xBix quaternary alloy on a Si (001) substrate, determining the composition, studying structural properties, relaxation mechanisms and surface morphology are presented. Using pulsed laser deposition, epitaxial growth of the Ga1-yInyAs1-xBix thin film was carried out on the Si (001) substrate. Using X-ray diffraction, it was established that the Ga1-yInyAs1-xBix film was grown with a large lattice mismatch (Δa/a = 7.838 %). It is shown that the film has a well-pronounced texture in the [001] growth direction, a lattice parameter of 5.856 Å. Using Medium Energy Ion Scattering, a decrease in the In concentration after a layer thickness ≈15 nm from 0.5 to 0.4 mol frac. was detected. An important result is the homogeneous distribution of Bi throughout the layer thickness. Structural studies allow for the conclusion that stress relaxation occurred because of shears by means of a nucleation of dislocations and a slip close-packed {111} planes, as well as twinning, which led to a change in composition after a thickness of ≈15 nm from the substrate and an increase in the surface roughness of the layer.