Improved Diffusion Barrier Properties and NiSi Thermal Stability for the Cu Contact with the Ru/TaSiN Stack on NiSi/Si

The thermal stability and electrical properties of Cu contact on NiSi/Si with diffusion barrier of Ru/TaN and Ru/TaSiN stacks were compared. The Cu/Ru/TaSiN system has better barrier performance and NiSi thermal stability than the Cu/Ru/TaN system does on the NiSi/Si substrate. It is found that Cu diffusing into NiSi/Si would cause formation of not only Cu 3 Si but also NiSi 2 . The thermal expansion of Cu is less on the Ru/TaSiN/NiSi system than on the other systems. The results show that good interface adhesion and thermal expansion between NiSi and the barrier are very important in the Cu on NiSi contact technology.