High resolution measurement of the step distribution at the Si/SiO2 interface

Abstract

With a recently developed high resolution LEED instrument spot profiles of the 00–beam of Si/SiO2 interfaces have been taken after the removal of the oxide. It is demonstrated, that beyond the half-width the full profile down to a hundredth of peak intensity gives valuable information. The distribution of terraces up to more than 50 nm contribute essentially to a sharp central spike, which is only visible with a high resolution system. Whereas with usual LEED optics only terraces up to about 20 nm are evaluated from spot profile, the present data for the first time allow an evaluation in an extended range of terrace widths besides step atom density. Model calculations show the influence of instrument response and of details of the terrace width distribution on the spot profile.