STRUCTURES OF CLEAN AND NICKEL-CONTAINING HIGH MILLER INDEX SURFACES OF SILICON

There are some discrepancies in the literature concerning the structur e of clean silicon surfaces with different orientations and the explan ation of the nature of phase transitions on such surfaces. Clean high Miller index surfaces of silicon and the effect of nickel adsorption o n their structure and stability have been studied by LEED and AES. We have found that the multitude of surface structures and phase transiti ons on these surfaces are due to nickel impurities, which may lead to the formation of surface structures on silicon at concentrations below the threshold sensitivity of the Auger spectrometer. A correlation ha s been founded between the surface nickel concentrations and the struc ture of silicon surfaces with different orientations. A number of prev iously unknown structures on silicon surfaces has been discovered.