Shearing orientation dependence of cleavage step structures on GaAs(110)

Scanning tunneling microscopy has been used to evaluate surface roughness a nd step structures of cleaved GaAs(110) surfaces. It is found that they ape dependent on the direction of the force applied during cleaving. The flatt est surface having fairly straight [111]-type steps is obtained when cleavi ng samples toward the [110] direction. Cleaving samples toward [001] also l eads to smooth surfaces with [001]-, [112]-, and/or [114]-type steps. In co ntrast, when cleaving samples toward [112] or [114], the surfaces obtained have many fluctuated atomic steps. We will discuss the observed shearing or ientation dependence of the cleavage step structures in terms of configurat ions of As-Ga bonds. (C) 2000 Published by Elsevier Science B.V. All rights reserved.