MORPHOLOGY AND DISTRIBUTION OF ATOMIC STEPS ON SI(001) STUDIED WITH SCANNING TUNNELING MICROSCOPY

We have studied the morphology and distribution of atomic steps on Si(001) with scanning tunneling microscopy. We find that native oxide removal at temperatures up to 1350 K leads to step pinning and bunching. Cleaning at temperatures above 1450 K leads to regular step distributions which reflect the macroscopic misorientation of the sample. Steps running parallel to the 2×1 dimer rows on the upper terrace are straight, whereas steps perpendicular to these rows are ragged.