DC-Resistive-Heating-Induced Step Bunching on Vicinal Si (111)

Step bunching on a 1°-misoriented Si (111) surface induced by DC resistive heating is observed by ultrahigh-vacuum scanning electron microscopy. Step band regions of the DC-heating-induced bunching surface break up into finer step bands (subbands) and (111) facets below the (7×7)↔(1×1) phase transition temperature (T c=830°C). The temperature dependence of bunching-inducing current direction on the vicinal surface is the same as that of nearly flat (111) surfaces previously reported, except that bunching is induced for the opposite current direction to nearly flat (111) surfaces below T c.