Step bunching, step wandering and faceting: self-organization at Si surfaces

Step bunching, in-phase step wandering and faceting are new morphological evolutions from smooth vicinal surfaces. They are formed by giving changes of externally controlled parameters on surfaces. Two cases on Si surfaces are presented in detail. One is caused by unidirectional drift forces on adatoms on the surfaces, i.e., surface electromigration due to direct current specimen heating. Newly formed step instabilities are due to a change of a kinetic parameter on the surface. The other case is caused by adsorption of foreign metal atoms on the Si surfaces. In this case step instabilities are due to changes of thermodynamic parameters on the surface. Step bunching, in-phase step wandering and faceting processes in two cases are interesting dynamics of self-organization at surfaces and can be useful for microfabrication of surfaces. Recent results of these dynamic processes on vicinal surfaces of Si(1 1 1) and (0 0 1) surfaces and high index Si surfaces studied by real space and reciprocal space observation methods mainly done by our group are reviewed.