Abstract
A mechanism for SiCl2 formation and desorption in the etching of Si(100 - (2 × 1) at low chlorine coverages is analyzed using first-principles calculations. We find that the two monochlorinated Si atoms of a surface dimer can rearrange into a metastable SiCl2(a) adsorbed species plus a Cl-free Si atom. Desorption of SiCl2 occurs via a two-step mechanism, in which the adsorbed species is preliminarily stabilized by the diffusion away of the free Si atom. The energy barrier to form SiCl2(a) is lower on a dimer next to a dimer vacancy than in an undamaged region of the surface, consistent with recent STM observation of preferential linear growth of etch pits along dimer rows.
Original language | English (US) |
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Pages (from-to) | 4877-4880 |
Number of pages | 4 |
Journal | Physical review letters |
Volume | 78 |
Issue number | 25 |
DOIs | |
State | Published - Jun 23 1997 |
Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)