Generation kinetics of pyramidal hillock and crystallographic defect on Si(111) vicinal surfaces grown with SiH₂Cl₂

The generation kinetics and surface morphology of crystallographic defects were investigated on Si(111) vicinal surfaces grown with SiH₂Cl₂. By chemical etching observation, it was found that on the Si(111) 0° off surface with a small misorientation angle the crystallographic defect always develops as a pyramidal hillock with different apex morphology depending on the type of defect. Dislocations, stacking faults and polycrystalline Si are associated with hillocks with sharp and flat apexes and bright particles, respectively. On the other hand, no hillocks were observed on the Si(111) 4° off surface with a large step density irrespective of the existence of such defects. This drastic change of the surface morphology of the crystallographic defect indicates that the crystallographic defect can play the role of growth nucleus of the hillock with a large growth rate on the Si(111) 0° off surface, leading to the growth of a triangular hillock independent of the type of defect. Therefore, without chemical etching of the as-grown surface, the pyramidal hillock can be employed as a finger print of a crystallographic defect, whose type is distinguished by giving attention to its apex morphology. Furthermore, the crystallographic defect generation was observed to be hardly affected by increasing step density in spite of the drastic disappearance of the corresponding hillock.