We have used reflection high‐energy electron diffraction to characterize the surface step structure of Si(001) vicinal surfaces tilted from 0.5° to 4° toward the [110] azimuth. The surface of small misorientation (0.5°, 1°) after a high‐temperature anneal was double‐domain with monolayer steps, while that of a large misorientation (4°) was single‐domain with bilayer steps. The single‐domain structure appeared for all samples during homoepitaxial growth. For surfaces tilted by 0.5° or 1°, the selective growth of the first half of a monolayer was observed which changed the surface from double‐domain with monolayer steps to single‐domain with bilayer steps.