Diploma Thesis - Erich Schmid Institute

8. Deposition of Thin Films
Deposition of Thin Films
8.1. Magnetron sputtering of polycrystalline Al thin films on Si(1 0 0)
Magnetron sputtering of polycrystalline thin films is a widely used deposition
technique. Thin layers of chromium, gold, titanium, aluminium and many other
materials can be produced using the technique in a deposition chamber
schematically depicted in Fig. 8.1. In the evacuated chamber, ionized gas atoms
(usually argon ions) are accelerated under influence of an electrical field towards a
target. The high kinetic energy enables the ions to strike out surface bound atoms
which are leaving, with rather low kinetic energy (some keV), the target’s surface in
all possible directions. A substrate, fixed usually on the opposited side of the
chamber, is covered by a thin film of the sputtered atoms. The advantages of the
magnetron sputtering process are a good control of process parameters, high purity
of the films and a possibility to use low process temperatures.
For the production of polycrystalline Al thin films on monocrystalline Si(1 0 0) wafers,
magnetron sputtering device installed at the “Institute of Physics, Technical University
Wien” was used. As a substrate for the specimen preparation, a 1 mm thick Si(1 0 0)
wafer cleaned using isopropanol and acetone was used. On this native-oxidized
silicon wafer, a polycrystalline aluminium thin film with a thickness of 2 µm was
deposited using magnetron sputtering. The deposition was performed at 150 °C
applying a pressure of 4 x 10 -3 mbar.
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Figure 8.1: A schematic view of a sputtering reactor
1 Vacuum chamber, 2 upper electrode, 3 plasma,
4 lower electrode, 5 gas inlet, 6 vacuum pump connection
7 substrate, 8 high frequency voltage, 9 target
10 plasma ion, 11 target atom
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