Berlin 2008 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 17: Poster I

HL 17.41: Poster

Monday, February 25, 2008, 16:30–19:00, Poster D

High mobility GaN based 2DEG heterostructures by MBE — •D. Broxtermann, M. Sivis, A. Bedoya Pinto, J. Malindretos, and A. Rizzi — IV. Physikalisches Institut and Virtual Institute of Spin Electronics (VISel), Georg-August Universität Göttingen, D-37077 Göttingen, Germany

In order to realize spin electronic devices using GaN diluted magnetic semiconductors as spin injectors or detectors, well-matched GaN-based semiconductor heterostructures for spin control are required. The Al_xGa_1−xN/In_yGa_1−yN heterostrucutures for x,y = 0 ... 0.2 are considered here. In our work we first optimize the MBE process of AlGaN/GaN heterostructures on MOCVD GaN templates. Thereby the GaN flux as well as the pretreatment of the substrates have been found to be crucial for good crystal quality. To obtain state of the art high mobility structures, we vary the AlGaN barrier width, the GaN cap layer thickness as well as the Al composition. The electrical properties are analyzed by magneto transport experiments and corresponding calculations of a self-consisting Schrödinger-Poisson solver.