Structural Change of Si(001) Surfaces after Alternating Current Heating

摘要

Si(001) vicinal surfaces heated with a sine wave of 10~4 Hz AC are investigated by using scanning reflection electron microscopy. Surfaces of 1X2 that consist of wide 1X2 terraces (the 1X2 dimer is perpendicular to the direction of the heating current) and narrow 2X1 terraces (the 2X1 dimer is parallel to the direction of the heating current) terraces were obtained at temperatures below 850 deg C. At temperatures between 850 deg C and 1100 deg C, on the other hand, double-domain surfaces where 2X1 and 1X2 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 deg C. At temperatures above 1100 deg C, the surfaces are composed of mosaic domains due to the evaporation of the atoms.