Berlin 2005 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Halbleiterphysik

HL 17: Poster Ib

HL 17.30: Poster

Freitag, 4. März 2005, 16:30–19:00, Poster TU F

Scanning Tunneling Microscopy of Substitutional Phosphorus Atoms on different Lattice Sites in the Si(111)-(2×1) Surface — •J. K. Garleff¹, M. Wenderoth¹, R. G. Ulbrich¹, C. Sürgers², and H. v. Löhneysen² — ¹IV. Physikalisches Institut, Universität Göttingen, D-37077 Göttingen — ²Physikalisches Institut and DFG Center for Functional Nanostrcutures (CFN), Universität Karlsruhe, D-76128 Karlsruhe

Substitutional phosphorus (P) atoms (N_D ≈ 6 × 10¹⁸cm⁻³) at the Si(111)-(2×1) surface were investigated by scanning tunneling microscopy (STM). The samples were prepared by in situ cleavage under ultra-high vacuum (UHV) conditions. The measurements were performed at low temperature (8 K) in a custom build STM. The P atoms were identified by their well-known characteristic voltage-dependent contrast [1]. At −0.5 V, the STM image exhibits an additional anisotropic protrusion that extends up to 10 nm along the individual π-bonded chains affected by the P atom. Four site-specific contrast patterns induced by the presence of P are observed in agreement with the four non-equivalent lattice sites for substitutional P atoms at the Si(111)-(2×1) surface [2]. The individual features are attributed to the local electronic properties of P atoms at the different lattice sites.

[1] T. Trappmann, C. Sürgers, and H. v. Löhneysen, Europhys. Lett. 38, 177 (1997)

[2] K. C. Pandey, Phys. Rev. Lett. 47, 1913 (1981)