J. Phys. IV France
Volume 12, Numéro 3, May 2002
Page(s) 97 - 101

J. Phys. IV France
12 (2002) Pr3-97
DOI: 10.1051/jp420020044

Electron transport in silicon nanostructures based on ultra-thin SOI

A. Pouydebasque1, 2, L. Montes1, J. Zimmermann1, F. Balestra1, D. Fraboulet3, D. Mariolle3, J. Gautier3, F. Schopfer2, V. Bouchiat2 and L. Saminadayar2

1  Institut de Microélectronique, Électromagnétisme et Photonique, 23 avenue des Martyrs, 38016 Grenoble cedex 1, France
2  Centre de Recherche sur les Très Basses Températures, 25 avenue des Martyrs, 38042 Grenoble cedex 9, France
3  LETI/DMEL, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble cedex 9, France

We present an experimental study of ultra-thin SOI-based nanostructures. The systems have a van der Pauw geometry, with a radius of 2  $\mu$m. The resistance per square $R_{\square}$ is first analyzed in the temperature range 300 K - 4.2 K, and for different conditions of back gate voltages ( ${\rm0 V}< V_g < {\rm 4 V}$). The magnetoresistance was measured at very low temperatures ( ${\rm 10~mK} < T < 900$ mK), for magnetic fields ${\rm -2500 G}< B < 2500$ G. The experimental results exhibit a negative magnetoresistance that we attribute to quantum interference effects due to time reversed electron paths and known as weak localization. Fundamental properties of the material at low temperatures such as the electron phase coherence length $l_\phi$, the elastic mean free path  l, and the mobility $\mu$ are then estimated throughout the obtained results.

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