Dresden 2017 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 36: Postersession I
DS 36.20: Poster
Mittwoch, 22. März 2017, 17:00–19:00, P2-EG
Modeling of current voltage characteristics of Schottky contacts on Ga2O3 and In2O3 — •Daniel Splith, Holger von Wenckstern, and Marius Grundmann — Universität Leipzig, Institut für Experimentelle Physik II, Leipzig, Germany
We present a model for the calculation of current voltage characteristics of Schottky contacts (SCs) taking into account barrier height inhomogeneities and variations of the net doping density in growth direction determining the spatial dependence of band bending. For each barrier height the band diagram was calculated using the finite element method. Subsequently, thermionic and thermionic field emission (TE and TFE) currents were calculated using the transfer matrix method. Additionally, charging currents were taken into account.
The model was used to calculate the IV characteristics of SCs on β-Ga2O3 and In2O3, utilizing the barrier parameters determined from temperature dependent IV measurements. Using a homogeneous doping profile for the β-Ga2O3, the modeled and measured temperature dependent characteristics are in good agreement. The modeled data shows that in the reverse direction, charging and TFE currents are dominant. For SCs on In2O3 the influence of the thickness of a Mg-doped layer on top of a nominally undoped thin film was investigated. Assuming a step-like doping profile and using the barrier parameters of the contact with the thickest Mg-doped layer, the modeled characteristics show a good agreement to the measured data for different layer thicknesses. The TFE current, while dominant for thin Mg-doped layers, is reduced with increasing layer thickness.