Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 14: Poster I
HL 14.82: Poster
Montag, 24. März 2003, 17:00–19:30, HSZ/P2
Direct patterning of GaN-heterostructures using an AFM with diamond tip — •A. Mühle1, U. F. Keyser1, R. J. Haug1, E. Oesterschulze2, and W. Knap3 — 1Institut für Festkörperphysik, Universität Hannover — 2Institut für Technische Physik, Universität Kassel — 3G.E.S.-Université Montpellier, France
We use an atomic force microscope equipped with an all-diamond tip to directly manipulate the surface of a GaN-heterostructure. Our heterostructure contains a two-dimensional electron gas (2DEG) only 20 nm below the surface. For the first time we are able to directly influence the 2DEG with an AFM-based lithographic process.
By applying an extremely high contact force of several mN we fabricate shallow grooves on the surface of the GaN. This leads to a depletion of the 2DEG underneath the groove and thus a tunneling barrier is created.
We analyse the transport properties of these barriers by magneto-transport experiments in a perpendicular magnetic field and at variable temperatures. With a simple model calculation we are able to estimate the height and width of the tunneling barriers.