Effect of tensile strain on B-type step energy on Si(001)-(2x1) surfaces determined by switch-kink counting

Scanning tunneling microscopy (STM) images of unstrained Si(001) and Si(001 ) grown tinder tensile strain have been analyzed to determine whether the S g step energy increases with applied tensile strain, as predicted by Xie et al. [Phys. Rev. Lett. 73, 3006 (1994)]. We did this using "kink counting" of STM images, using a new "switch-kink" counting method that is better sui ted for analysis of STM images in which the local azimuthal miscut angle ch anges. Our measurements indicate that the S-B step energy does increase wit h tensile strain, in qualitative agreement with the predictions of Xie et a l., although not as strongly as their calculations suggested. (C) 1999 Amer ican Vacuum Society. [S0734-2101(99)06204-1].