Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 5: Transporteigenschaften
HL 5.1: Vortrag
Montag, 8. März 2004, 10:15–10:30, H14
Lateral tunneling spectroscopy in a two-dimensional electron gas — •Jean-Laurent Deborde1, Saskia F. Fischer1, Ulrich Kunze1, Dirk Reuter2, and Andreas D. Wieck2 — 1Lehrstuhl für Werkstoffe und Nanoelektronik, Ruhr-Universität Bochum, D-44780 Bochum — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum
A direct observation of lateral tunneling, via electron energy spectroscopy, in a two dimensional electron gas (2-DEG) is reported. A lateral tunneling field-effect transistor has been fabricated using a GaAs/AlGaAs heterostructure and atomic force microscope (AFM) lithography. This technique permits to form a groove with a low width to height aspect ratio (3.5 and less). A furrow is dynamically ploughed by the vibrating tip of the AFM into a 5 nm thick polymer layer on the surface of the semiconductor [1]. Wet chemical etching transfers the line pattern resulting in a 70 nm wide and 20 nm deep groove generating a tunneling barrier in the channel. A Schottky gate is deposited on the top of the device in order to control both the charge carrier density and the barrier height. The characteristic conductance vs. source-drain bias shows structures which indicate electron tunneling through the potential barrier. The 2-DEG Fermi energy of 13 meV is determined from the tunneling spectrum.
The realization of a lateral resonant tunneling field-effect transistor using this particular fabrication technique is further anticipated.
[1] U. Kunze, Superlatt. Microstruct. 31, 3 (2002).