Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 68: Poster Session: GaN: devices & preparation & characterization; III-V semiconductors; Photonic crystals; Semiconductor lasers

HL 68.11: Poster

Mittwoch, 13. März 2013, 16:00–20:00, Poster A

Design of a high temperature Hall measurement setup — •Dominik Beck, Matthias Hocker, and Klaus Thonke — Institute of Quantum Matter / Semiconductor Physics Group, Ulm University, D-89081 Ulm, Germany

A Hall measurement setup is developed for the temperature dependent characterization of iron doped gallium nitride and other highly resistive materials. For this purpose the whole setup has to meet some special technical requirements.

The Hall chamber has to be vacuum tight to prevent samples from oxidation and other modifications due to reactions with environmental gases. For the thermal activation of deep impurities, the setup is designed to reach temperatures up to 800 ^∘C. Thermal isolation is realized with cascaded stainless steel shields, and water cooling of the outer walls keeps them at low temperature.

Another important point is the measurement of very small electrical currents due to the high resistivity of the samples. The whole setup is optimized for these low currents and high voltages up to 100 V for Hall and Van der Pauw measurements.

Furthermore, the whole setup is designed for minimal size to fit the given geometry of the magnetic pole pieces.