Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 70: Poster Session: Devices; Preparation and characterization; C/diamond; Si/Ge

HL 70.20: Poster

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

Thermoelectric measurements of strained silicon using electrical and optical methods — •Jiehong Jin, Markus Hagedorn, Beata Kardynal, Stephan Wirths, Dan Mihai Buca, Detlev Grützmacher, and Toma Stoica — Peter Grünberg Institut (PGI-9), Jülich-Aachen Research Alliance (JARA), Forschungszentrum Jülich, 52425 Jülich, Germany

Semiconductor nanowires (NWs) have been shown to greatly suppress phonon heat conduction without a significant decrease in the Seebeck coefficient or electrical conductivity. Variety of methods can be used for structure fabrication. Irrespective of the fabrication process the specific geometry of NWs renders the heat transport measurements difficult. In this work, NWs of strained silicon on insulator (SSOI) were defined using e-beam lithography with metallic lines for local heaters and thermoelectric contacts. Two different methods of measuring temperature along the NWs are compared. We measured the temperature as resistance change of the thin metal lines in contact with the NWs. We also used the temperature dependence of the Si-Si Raman vibration mode to measure the NWs temperature. Both techniques can be used as accurate thermometers. However, optical readout using micro-Raman scattering proved to be more flexible. Using this technique, the temperature change along the NWs can be monitored with a resolution of the order of laser wavelength. Importantly, since the Raman peaks of the strained Si NWs and the substrate are clearly separated, the parasitic heat transport into the substrate can be evaluated.