Scanning-tunneling-microscope study on the {111} cross-sectional surface of Si/Ge layered material

We studied the {111} cross-sectional surface; bf epitaxially grown Si/Ge(111) samples. We cleaved the samples in an ultrahigh vacuum, and investigated their (111) cross sections in situ by using a scanning tunneling microscope. After annealing, 7x7 and c(2x8) reconstructions appeared, the first: at the Si side and the latter at the GE: side. In the transient region between the 7x7 and the c(2x8) reconstructions, the adatoms were arranged with 2x2 and c(2x4) short-range orderings. We also observed small 7x7 domains. These 7x7 domains adjoined to{110}-oriented steps. In a detailed analysis of the terrace height and adatom sites, we related these steps to the dissociation of the misfit dislocation with b = a/2[101]. We found the origin of the local 7x7 domains to be compressive stress with. dislocations. [S0163-1829(99)00908-X].