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R. Zawrel:
"Four-Point Probe Resistivity Measurements on Polycrystalline Thin Films and Complex Metallic Alloy Coatings";
Betreuer/in(nen): C. Eisenmenger-Sittner; Institut für Festkörperphysik, 2011; Abschlussprüfung: 17.02.2011.

ABSTRACT

The resistivity of thin Cu, Al, AlCu and AlCuFeB films with varying thickness was measured using a tungsten carbide tipped four-point probe from Jandel, a Keithley nanovoltmeter, a Keithley current source and a computer data collection program. The resistivity was obtained through a correction factor dependent on the sample geometry.
The thin AlCu and AlCuFeB films were coated on glass substrates, which were heated to 400°C and 500°C before and during coating.
The thin Al and Cu films deposited at room temperature were also coated on glass substrates. The resistivity measurements showed that sheet resistance and resistivity increased with decreasing film thickness. As soon as the thickness reaches the electron mean free path, the electrons are scattered more often and so the resistivity increases. Furthermore, the experiments showed a big difference in resistivity between AlCu films deposited at room temperature and AlCu films deposited at 400°C. A crystalline structure was formed because of the heating during the sputter process. This led to a lower resistivity of AlCu films that were deposited at 400°C.
Additionally, with the help of a resistivity simulation program the grain sizes of Cu, Al and AlCu films were determined to use the Mayadas-Shatzke Fuchs-Sondheimer fit to find out how the electrons are scattered at grain boundaries.