Si(001) vicinal surfaces heated with a sine wave of 10⁴ Hz AC are investigated by using scanning reflection electron microscopy. Surfaces of 1×2 that consist of wide 1×2 terraces (the 1×2 dimer is perpendicular to the direction of the heating current) and narrow 2×1 terraces (the 2×1 dimer is parallel to the direction of the heating current) terraces were obtained at temperatures below 850^oC. At temperatures between 850^oC and 1100^oC, on the other hand, double-domain surfaces where 2×1 and 1×2 terraces are arranged regularly with approximately equal widths were formed. The driving force for growth changes from thermal effect to evaporation effect at about 850^oC. At temperatures above 1100^oC, the surfaces are composed of mosaic domains due to the evaporation of the atoms.