HOLOGRAPHY WITH KIKUCHI ELECTRONS - DIRECT IMAGING OF ORDERED TRIMERSON AU SI(111)(ROOT-3X-ROOT-3)R30-DEGREES AND SB/SI(111)(ROOT-3X-ROOT-3)R30-DEGREES INTERFACES/

The structural bases on the metal/semiconductor interfaces, such as go ld trimers on the Au/Si (111)(root 3 x root 3)R30 degrees surface and antimony trimers on the Sb/Si(111)(root 3 x root 3)R30 degrees surface , can be imaged directly with a simple inversion of low-energy (<600 e V) Kikuchi-electron patterns (Kikuchi-electron holography-KEH). The re lative positions of the building blocks (trimers) on the adsorbates to the substrate atoms are also determined. This short-range-order KEH t ool, which provides the 3D Patterson function, can be viewed as a twin of grazing-incidence X-ray diffraction. Using direct structural infor mation obtained by KEH, one can greatly reduce the tested models in a complete trial-and-error structural-determination process.