Time evolution of DC heating-induced in-phase step wandering on Si(1 1 1) vicinal surfaces

The time evolution of in-phase step wandering (IPSW) on Si(1 1 1) vicinal surfaces induced by direct current heating and its off-angle dependence were studied. The substrate temperature of 1100°C was chosen at which a wavelength of IPSW pattern is the maximum. The wavelength keeps nearly constant at approximately 7 μm as a function of annealing time and does not depend on off-angle. The amplitude of wandering steps in the IPSW pattern increases with annealing time and approaches its saturation value after 24 h, irrespective of off-angle. The saturation value depends on off-angle and decreases with increasing off-angle or decreasing mean step–step distance. This suggests that the amplitude of wandering steps is affected by step–step interaction.