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HL: Fachverband Halbleiterphysik
HL 25: Poster 1
HL 25.97: Poster
Mittwoch, 7. September 2022, 18:00–20:00, P2
In depth comparison of Raman and Hall measurements for the determination of the electrical transport parameters of N-doped 4H-SiC — •Hannes Hergert1,2, Matthias T. Elm1,2,3, and Peter J. Klar1 — 1Institute of Experimental Physics I, Giessen, Germany — 2Center for Materials Research, Giessen, Germany — 3Institute of Physical Chemistry, Justus Liebig University, 35392 Giessen, Germany
A precise characterisation of the impact of doping on the electronic transport properties is necessary for the application of silicon carbid (SiC) in semiconductor devices. Hall effect measurements yield reliable results for mobility and carrier density but electrical contacts are needed. These are often not desired. An alternative approach is the analysis of the longitudinal optical phonon electron plasma coupled (LOPC) mode using Raman spectroscopy. This approach also delivers non-invasively information about the charge carrier density and the electron mobility. In this work, we compare the results obtained by Hall and Raman measurements. We show that the effective carrier density and the mobility obtained by Hall measurements deviate from those determined using Raman spectroscopy. The deviations arise as only electrons in the conduction band couple to the LO mode, while electrons in the impurity band do not, but still contribute to the electrical transport. To extract the charge carrier density in the conduction band from Hall measurements, a three-band model is employed. In addition, the two measurement methods yield different values of the mobility due to its frequency-dependence.