No abstract

No abstract

No abstract

A ruthenium film on a NiSi/Si substrate was evaluated for barrier performance in Cu contact metallization. The films were deposited by magnetron sputtering using Ni, Ru, and Cu targets. The low-resistivity NiSi film was initially produced from an Ni/Si substrate, and Ru and Cu films were sequentially deposited on the NiSi/Si substrate so that barrier performance could be studied. Barrier properties were elucidated by four-point probe measurement, x-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy, and transmission electron microscopy. The stability temperatures of 600°C (Cu/NiSi/Si) and 650°C (Cu/Ru/NiSi/Si) were systematically verified and are discussed. Structural analysis indicated that the failure mechanism involved penetration of the Cu through the Ru/NiSi stacked film at a specific temperature, which induced the accelerated dissociation of the NiSi. Interposition of an Ru layer between the Cu and the NiSi/Si effectively prevented intermixing and substantially improved the thermal stability in the Cu/NiSi/Si stack films.

No abstract