This study finds that the resistivity of Ta/TaNx films depends on both the Ar re-sputtering amount and the N2 flow of under-layer TaNx deposition. As the Ar re-sputtering amount of under-layer TaNx films increases, the resistivity of Ta/TaNx bi-layers decreases because Ar re-sputtering can provide a driving force to make the upper Ta metal phase transformation from a high-resistivity β-phase to a low-resisitivty α-phase. On the other hand, increasing the N2 flow of under-layer TaNx deposition also makes the Ta resistivity trend down. The behavior is because increasing the N2 flow can lower the energy barrier of phase transformation from β-phase Ta to α-phase Ta. A proposed model is provided to describe the effect of the Ar re-sputtering amount and the N2 flow of under-layer TaNx deposition on the phase transformation of upper Ta metals.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry