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CVD Co film was investigated as an alternative barrier layer to the conventional PVD TaN\Ta in V1\M2 structure for 32nm node. We improved via filling performance and upstream (V1→M2) electromigration (EM) lifetime by more than three times. Excellent step coverage of CVD barrier makes it possible to reduce the thickness of the barrier metal by 30% and to increase the volume of Cu in metal lines. RC delay also reduced with decrease in resistance. Since adhesion at the interface between the barrier-Co and Cu also is strong, migration of Cu atoms is dramatically slowed down. EM in the via is finally deterred due to absence of pre-existing voids, consequently lifetime increases. This CVD Co process is expected to be beneficial for the next technology generation beyond 20nm node.

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Pure and conducting RuO2 thin films were deposited on a Si substrate at 250–450 °C using Ru(C11H19O2)3 as a precursor by low pressure metal organic chemical vapor deposition (MOCVD). At a lower deposition temperature, the smoother and denser RuO2 thin films were deposited. The amount of O2 addition did not seriously affect the properties of the RuO2 thin film. The RuO2 thin films which were crack free and well adhered onto the substrates showed very low resistivity of 45–60 μΩ cm. At a lower deposition temperature and a smaller amount of O2 addition, RuO2 thin films showed better step coverage, indicating that MOCVD RuO2 thin films from Ru(C11H19O2)3 can be applied for an electrode of high dielectric thin films for a capacitor of ultralarge scale integrated dynamic random access memory.

Platinum thin films were deposited on Si02/Si substrates at a deposition temperature of 325°C by metallorganic chemical vapor deposition using Pt-hexafluoroacetylacetonate as a precursor. It was found that the addition of the proper amount of 02 gas was essential to deposit high-quality Pt thin films. Dense Pt thin films with smooth surfaces and high electrical conductivity were deposited above a critical 02 flow rate of 50 sccm. The introduction of 02 gas made the Pt films partially oxidized, resulting in the reduction of their surface and grain boundary energy. Therefore, wettability of the Pt thin films on 5i02/Si was improved and the grain growth of the films by a postdeposition annealing was suppressed as the addition of 02 was increased during the deposition.