Reflectance difference spectroscopy of highly oriented (2×1) reconstructed Si(001) surfaces

We report on reflectance difference spectroscopy (RDS) from highly oriented, single-domain (2×{}1) reconstructed Si(001) surfaces. It is much closer to the ``ideal'' surface than the vicinal one commonly used in RDS. It was prepared using electromigration technique which resulted in large terraces (5 {μ}m). Certain features that are attributed to 2×{}1 and 2×{}2 structures are significantly changed in spectra obtained from vicinal surfaces. This indicates that the steps suppress formation of the 2×{}2 structures. The vicinal surfaces may have limited practical utility in RDS studies of the Si(001) surface.