2-DIMENSIONAL ORDERING OF SELF-ASSEMBLED GE ISLANDS ON VICINAL SI(001) SURFACES WITH REGULAR RIPPLES

Two-dimensional ordering is achieved in a single layer of self-assembl ed Ge islands fabricated by molecular beam epitaxy on vicinal Si(001) surfaces with regular ripples caused by step bunching. The ripples wit h a typical period of about 120 nm lead to the long-range lineup of th e Ge islands along their directions, while the strong repulsive intera ction between the dense Ge islands determines their relative arrangeme nt on different step bunches of a ripple. The ordering pattern can be tuned by the Ge coverage and the direction of the ripples. The orderin g also helps to improve the size homogeneity of the Ge islands. (C) 19 98 American Institute of Physics.