Dresden 2006 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 3: III-V semiconductors I
HL 3.4: Vortrag
Montag, 27. März 2006, 11:00–11:15, POT 51
Evidence of material mixing during local anodic oxidation nanolithography — •S. Heun1, G. Mori1, M. Lazzarino1, D. Ercolani1, G. Biasiol1, A. Locatelli2, and L. Sorba1 — 1Laboratorio Nazionale TASC INFM-CNR, 34012 Trieste, Italy — 2Sincrotrone Trieste, 34012 Trieste, Italy
We investigated the chemical properties of nanostructures fabricated by local anodic oxidation (LAO) on epitaxial GaAs/AlAs/GaAs layers by means of laterally-resolved photoemission spectroscopy. We find evidence for the unexpected presence of Al compounds located in the topmost surface layers of the LAO structures. We studied the evolution of the surface chemical composition of these nanostructures as a function of x-ray exposure time (photon energy hv=130 eV), and we found a reduction in the amount of the surface Ga oxide compounds with respect to the Al compounds [1]. Our results cannot be explained within the framework of the commonly accepted mechanism that describes the growth of the LAO oxides in terms of diffusion of oxygen-rich ions through the growing oxide. A more general mechanism that explains our experimental findings is proposed [2].
[1] G. Mori, M. Lazzarino, D. Ercolani, G. Biasiol, A. Locatelli, L. Sorba, and S. Heun, Nucl. Instrum. Methods Phys. Res. B, in press.
[2] G. Mori, M. Lazzarino, D. Ercolani, G. Biasiol, L. Sorba, S. Heun, and A. Locatelli, J. Appl. Phys., in press.