Step morphologies on small-miscut Si(001) surfaces

The morphologies of single height atomic steps were studied on Si(001) samples with a miscut of ∼0°-0.05°using dark-field low-energy electron microscopy. In addition to the previously observed wavy step phase we identify a ''hilly'' phase at miscut angles <0.03°. This phase exhibits steps in excess of those required by the local miscut, but their morphology is qualitatively different from the straight steps predicted by theory. © 1993 The American Physical Society.