ORIGIN OF RIPPLED STRUCTURES FORMED DURING GROWTH OF SI ON SI(001) WITH MBE

During epitaxial growth of silicon on Si(001) with MBE a rippled struc ture is formed on the surface. This rippled structure is akin to rippl es observed in sand when water has flown over it. Experiments combinin g X-ray crystallography, optical microscopy and atomic force microscop y have been used to determine the microscopic details of the rippled s tructure. We find that the rippled structure is caused by correlated k ink bunching and not by step bunching. A model is presented for the mi croscopic mechanism yielding deviations of the kink distribution from the equilibrium distribution, which are large enough to cause step-ste p interactions.