AVS 45th International Symposium
    Nanometer-scale Science and Technology Division Monday Sessions
       Session NS+EM+SS-MoA

Paper NS+EM+SS-MoA8
Cross Sectional STM Study on MBE-grown Si/Ge(111) Interface

Monday, November 2, 1998, 4:20 pm, Room 321/322/323

Session: Cross-sectional Scanning Tunneling Microscopy of Semiconductors
Presenter: H. Hirayama, Tokyo Institute of Technology, Japan
Authors: H. Hirayama, Tokyo Institute of Technology, Japan
M. Ohmori, Tokyo Institute of Technology, Japan
K. Takayanagi, Tokyo Institute of Technology, Japan
Correspondent: Click to Email
We studied the (111) cross sectional surface of MBE grown Si/Ge(111) samples. Samples were cleaved in ultra-high vacuum, and their (111) cross s ection were investigated in-situ by using STM. On the as-cleaved surface, 2x1 reconstruction were observed at both Si and Ge side. After annealing, 2x1 reconstruction changed to 7x7 and c(2x8) on the Si and Ge layer, respec tively. At around the interface, 7x7 reconstruction changed to c(2x8) reco nstruction in moving from Si to Ge side. But, the transition from 7x7 to c( 2x8) was not abrupt. The transient region of the width of c.a.200nm was obs erved. In the transient region, adatoms arranged with 2x2 and c(2x4) shor t range orderings. Patchy domains of 7x7 reconstruction, which was accompa nied with (110)- oriented grooves and non-double layer height steps, were a lso observed in the sea of 2x2 and c(2x8) arrangement of adatoms. In a det ailed analysis of adatom arrangement, we found that the non-double layer hei ght step was caused by the glide in the (111) plane parallel to the substr ate. The groove was triggered by partial dislocations at the edge of the gild region. The strain field with the glide-induced step and grooves modifi ed the surface strain locally, and caused patchy 7x7 domains.