Direct Observation of a β -SiC(100)- c ( 4 × 2 ) Surface Reconstruction
Résumé
We provide the first direct observation of a b-SiCs100d-cs4 3 2d surface reconstruction. The experiments are performed using high-resolution scanning tunneling microscopy (STM). Flat surfaces having a long range order are grown. Individual Si dimers are identified and form a centered pseudohexagonal pattern give a cs4 3 2d array. Further support for Si-dimer identification is provided by theoretical STM image calculations. The results suggest a model of dimer rows having alternatively up and down dimers (AUDD) within the row, in an “undulating” type of arrangement reducing the surface stress. Hence the b-SiCs100d- and Sis100d-cs4 3 2d surface reconstructions are very different.