| AVS 54th International Symposium | |
| Surface Science | Monday Sessions |
| Session SS2-MoM |
| Session: | Surface Structure, Growth, and Etching of Silicon and Germanium |
| Presenter: | A. Agrawal, University of Illinois at Urbana-Champaign |
| Authors: | A. Agrawal, University of Illinois at Urbana-Champaign R.E. Butera, University of Illinois at Urbana-Champaign J.H. Weaver, University of Illinois at Urbana-Champaign |
| Correspondent: | Click to Email |
We use scanning tunneling microscopy to show that Cl2 dosing of Cl-saturated Si(100)-(2x1) at elevated temperature leads to uptake beyond "saturation". The surface then evolves along a new etching pathway that involves insertion of extra Cl, denoted Cl(i), in Si-Si dimer bonds or back-bonds, diffusion of Cl(i) to form the volatile precursor, and pairwise desorption of SiCl2. Insertion is made possible by chemisorption that is mediated by dangling bond sites. Upon dissociation, one Cl atom adsorbs at the dangling bond while the other inserts with ~10% probability. The dangling bonds required for insertion are produced by phonon-activated electron-stimulated desorption of atomic Cl from the surface. These studies establish a novel form of Cl2 dissociative chemisorption, and this should stimulate further investigations into surface dynamics.