Platinum thin films were grown at 300 °C by atomic layer deposition (ALD) using (methylcyclopentadienyl)trimethylplatinum (MeCpPtMe3) and oxygen as precursors. The films had excellent uniformity, low resistivity, and low-impurity contents. Structural studies by X-ray diffraction showed that the films were strongly (111) oriented. Growth rates of 0.45 Å cycle-1 were obtained with 4 s total cycle times. The film thickness was found to linearly depend on the number of the reaction cycles. Also, the possible reaction mechanism is discussed.

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Thin films of metallic ruthenium were grown by atomic layer deposition (ALD) in the temperature range 275±400 C using bis(cyclopentadienyl)ruthenium (RuCp 2 ) and oxygen as precursors. The ruthenium films were grown on thin Al 2 O 3 and TiO 2 films on glass. X-ray diffraction (XRD) analysis indicated that the films were polycrystalline metallic ruthenium and scanning electron microscopy (SEM) studies showed that the films had excellent conformality. The impurity content of the films, as measured by time-of-flight elastic recoil detection analysis (TOF-ERDA), were very low. All the films had resistivities below 20 lX cm.

The low limit of the deposition temperature for atomic layer deposition (ALD) of noble metals has been studied. Two approaches were taken; using pure oxygen instead of air and using a noble metal starting surface instead of Al2O3. Platinum thin films were obtained by ALD from MeCpPtMe3 and pure oxygen at deposition temperature as low as 200 °C, which is significantly lower than the low-temperature limit of300 °C previously reported for the platinum ALD process in which air was used as the oxygen source. The platinum films grown in this study had smooth surfaces, adhered well to the substrate, and had low impurity contents. ALD of ruthenium, on the other hand, took place at lower deposition temperatures on an iridium seed layer than on an Al2O3 layer. On iridium surface, ruthenium films were obtained from RuCp2 and oxygen at 225 °C and from Ru(thd)3 and oxygen at 250 °C, whereas no films were obtained on Al2O3 at temperatures lower than 275 and 325 °C, respectively. The crystal orientation of the ruthenium films was found to depend on the precursor. ALD of palladium from a palladium β-ketoiminate precursor and oxygen at 250 and 275 °C was also studied. However, the film-growth rate did not saturate to a constant level when the precursor pulse times were increased.