Evaluation of properties of Ta–Ni amorphous thin film for copper metallization in integrated circuits

TaxNi1−x (x=0.65 and 0.50) thin films were prepared on p-type (1 0 0) Si substrate by magnetron dc sputtering as a barrier film with a high crystallization temperature and a low resistivity for Cu metallization. The failure properties of the studied films were elucidated using a four-point probe, X-ray diffractometry, scanning electron microscopy and transmission electron microscopy. The results indicate that as-deposited thin films had a glassy structure. The resistivity and failure temperature of TaxNi1−x (x=0.65 and 0.50) thin films were about 240.4 μΩ cm and 700 °C and 170.3 μΩ cm and 700 °C, respectively. The experimental findings revealed that the failure mechanism of the studied films involved the initial dissociation of the barrier layer annealed at a specific elevated temperature, and further silicidation with the underlying Si substrate.