Epitaxy of 3d Metals on Semiconductors

Growth of fcc Mn on GaAs(001), as an example of the lattice-mismatched epitaxy of 3d metals on semiconductors, has been studied using reflection high energy electron diffraction (RHEED), X-ray photoelectron spectroscopy (XPS) and the high resolution transmission electron microscope (HRTEM). The result shows that the interface structure plays a critical role in the epitaxial growth of 3d metals on semiconductors. A new recipe is proposed to search for more epitaxially grown 3d metal phases.

A Model for Lattice-Mismatched Epitaxy: A Continuum View

To date, primarily only idealized equilibrium models for the growth mode and strain relaxation of elastically strained overlayers have been proposed. Here we present a general continuum model for lattice-mismatched epitaxy. As molecular beam epitaxy is inherently a nonequilibrium growth process, surface diffusion kinetics is incorporated in the model. Additionally, a new strain relaxation mechanism in a dislocation-free film is considered. Experimental support for our view is obtained from measurements made by reflection high energy electron diffraction, scanning tunneling microscopy, and transmission electron microscopy on the growth of InGaAs on GaAs(100). These results demonstrate the strong effects which strain, surface diffusion kinetics, and surface energy have on growth mode. From analytical and numerical analysis in 1 + 1 dimensions, the interrelationship of such physical factors is revealed. Our improved understanding enables control over the growth behavior of strained-layer superlattices and heterostructures.