Ma. Elkhakani et al., IRIDIUM THIN-FILMS DEPOSITED BY RADIOFREQUENCY MAGNETRON SPUTTERING, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 16(2), 1998, pp. 885-888
Citations number
19
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
Deposition of metallic iridium thin films has been achieved by sputter
ing an Ir target with argon. The deposition of the Ir films was invest
igated at argon gas pressures in the (10-40) mTorr range with various
rf power densities. The stress, resistivity, and structure of the Zr f
ilms were systematically determined as a function of both the Ar press
ure and the rf power density. While all the deposited Ir films are pol
ycrystalline with a preferred (111) orientation, not only their stress
but also their resistivity were found to be particularly sensitive to
the Ar gas pressure. As for many sputtered metal thin films, the stre
ss of Ir films, deposited at a power density of 5 W/cm(2), drastically
changes from highly compressive (-2 GPa) to highly tensile (+1.2 GPa)
in a relatively narrow range of Ar pressure (10.5-25.5 mTorr). Likewi
se, the room-temperature resistivity of Ir sputtered films changes by
a factor of about 5 when the Ar pressure is increased from 22.8 to 36.
0 mTorr. Deposition conditions yielding Ir films which combine the low
est resistivity (17 mu Ohm cm) and very low stress levels (few tens of
MPa) are identified. Finally, it is established that the stress of Ir
films scaled linearly with the lattice-parameter dilatation of the (1
11) preponderant phase. (C) 1998 American Vacuum Society. [S0734-2101(
98)04302-4].