InAs/InP(0 0 1) quantum wire formation due to anisotropic stress relaxation: in situ stress measurements

We report in situ and in real time quantitative measurements of stress along [1 1 0] and directions during the formation of InAs/InP(0 0 1) quantum wires (QWr) and consequent stress relaxation. Results show a strong stress anisotropy due to the distortion of As–In bonds along [1 1 0] and As–As dimerization along [1 1 0]. This anisotropy is claimed to be the origin of QWr formation instead of self-assembled quantum dots. Anisotropic stress relaxation associated to QWr formation is shown to be characteristic of heteroepitaxial systems involving different group V elements grown by MBE under group V stabilized surface (2×4 reconstruction).