Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
HL: Halbleiterphysik
HL 9: Poster I
HL 9.6: Poster
Montag, 27. März 2006, 15:15–17:45, P3
Spatial fluctuations of the local potential in Silicon doped GaAs — •K. Teichmann1, S. Loth1, M. Wenderoth1, R. G. Ulbrich1, and U. Kretzer2 — 1Universität Göttingen, IV. Physikalisches Institut, Germany — 2Freiberger Compound Materials GmbH, Freiberg, Germany
We investigated highly Silicon doped GaAs (10+19 cm−3). Silicon is typically incorporated as a shallow donor, and is known to show strong autocompensation at high doping concentrations [1]. In our measurement we used UHV scanning tunneling microscopy at 8K. We prepared our sample as {110} cleavage plane. In particular we investigated distribution of dopants. In addition constant current topographies reveal a large amount of dopant induced defects. Both are not statistically distributed and show significant clustering on a length scale of several nanometers. By scanning the same region of the sample with different voltages (multibias spectroscopy) and by performing dI/dz spectroscopy we studied the correlation between the local dopant distribution and the electrostatic potential (φel.stat.(x,y)) as well as the local apparent barrier height.
[1] C. Domke et al., Phys. Rev. B 54, 10288 (1996).