Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 14: Heterostructures
HL 14.4: Vortrag
Montag, 25. Februar 2008, 10:15–10:30, ER 164
Tunneling spectroscopy of a p-i-n diode interface — Sebastian Loth1, •Martin Wenderoth1, Karen Teichmann1, Jan Homoth1, Karolin Löser1, Rainer G. Ulbrich1, Stefan Malzer2, and Gottfried H. Döhler2 — 1IV. Physikalisches Institut, Georg-August-Universität Göttingen, Germany — 2Universität Erlangen-Nürnberg, Max-Planck-Research Group, Institute of Optics, Information, and Photonics, Germany
The performance of modern semiconductor devices is largely influenced by the spatial distribution of dopants in the device’s active region on the nanoscale. Since the late 80’s Scanning Tunneling Microscopy (STM) was employed to study the local properties of p-n interfaces [1]. Most studies were carried out on p-n superlattices allowing the investigation of intrinsic features accessible without applied bias across the diode.
Here, a single GaAs p-i-n diode heterostructure is investigated with Cross-Sectional STM (X-STM) in a three-terminal configuration. External source and drain contacts control the electric field across the junction. Then, the diode’s active region is mapped with atomic resolution. Local I(V)-spectroscopy (STS) directly resolves the band edge alignment from p to n for different diode bias conditions. The effect of the external electric field on the spatial and spectral images of individual dopant atoms in the active layer is discussed.
This work was supported by the DFG-SPP 1285 and the German National Academic Foundation.
[1] P. Muralt et al., Appl. Phys. Lett. 50, 1352 (1987).