Effect of thickness scaling on the permeability and thermal stability of Ta(N) diffusion barrier
2019
Abstract Molecular and atomic permeability, thermal stability and interfacial reactions of ultrathin Ta, TaN and Ta/TaN stack as barrier to Cu/low - k interconnects have been studied. It is shown the barrier layers containing TaN and Ta/TaN have good thermal stability and barrier properties when their thickness is >3.5 nm while Ta cannot withstand 450 °C annealing. The thinner barriers are permeable for neutral molecules like heptane and demonstrate degradation of resistivity during the thermal anneal at 450 °C. Penetration of Ta precursors into low-k and formation of TaO/TaC type of bonds increase the dielectric function of low-k dielectric. Our results show that, on the low-k material with 23% porosity and 0.9 nm pore radius, the PVD deposited Ta(N) films
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
42
References
5
Citations
NaN
KQI