In situ measurements of InAs and InP (0 0 1) surface stress changes induced by surface reconstruction transitions

Abstract

The anisotropic surface stress changes associated with the transition between different surface reconstructions of InAs and InP (0 0 1) surfaces are measured in situ and in real time in a molecular beam epitaxy (MBE) system. Reflectivity anisotropy of the surface measured at 1.96 eV, together with reflection high energy electron diffraction (RHEED) pattern, are used in order to identify the surface reconstructions, and the monitoring of the substrate curvature evolution to determine the variations in surface stress. Our results show the important contribution to the surface stress of the dimers present in these reconstructed surfaces. Furthermore, we provide for the first time quantitative values of the surface stress changes due to the transition between surface reconstructions for these III–V semiconductors compounds. We obtain values for these changes up to 0.7 Nm−1, that is, of the same magnitude as the stress induced by deposition of one monolayer during growth of lattice-mismatched III–V semiconductor heteroepitaxial systems. This points out the great importance of surface stress evolution in this kind of processes.