Seedless Cu Electroplating on Ru-W Thin Films for Metallisation of Advanced Interconnects
Abstract
:1. Introduction
2. Results and Discussion
3. Experimental
3.1. Ru-W Thin Film Deposition
3.2. Cu Electroplating
3.3. Structural and Chemical Characterisation of Substrate and Cu Films
4. Conclusions
- ▪
- Thin Cu films can be directly electroplated on near equimolar Ru-W thin films using a conventional acidic electrolyte.
- ▪
- Under the flat substrate configuration and electroplating conditions herein utilised, a minimum average current density between 3 and 5 mA·cm−2 was required to achieve substrate coverage, regardless of the current application mode.
- ▪
- A wide range of particle sizes formed on the substrate. A variable thickness, compact Cu film was partially interrupted by large star-like/dendritic Cu particles that prevented substrate coverage in their vicinity.
- ▪
- A pulse-reverse current effectively reduced the particle size, which contributed to a smoother film but appeared unable to eliminate large Cu particles. Hydrogen evolution was noticeable above 6 mA·cm−2.
- ▪
- Substrate coverage was not complete, and this requires improvement; however, a continuous interface between Cu and Ru-W was formed.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Condition | mA·cm−2 | s | mC | mA·cm−2 | mA·cm−2 | ms | ms |
---|---|---|---|---|---|---|---|
DC-2 | 2 | 150 | 300 | - | - | - | - |
DC-5 | 5 | 60 | 300 | - | - | - | - |
DC-10 | 10 | 30 | 300 | - | - | - | - |
PRC-5 | 3 | 100 | 300 | 5 | 5 | 20 | 5 |
PRC-10 | 6 | 50 | 300 | 10 | 10 | 20 | 5 |
PRC-20 | 12 | 25 | 300 | 20 | 20 | 20 | 5 |
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Santos, R.F.; Oliveira, B.M.C.; Savaris, L.C.G.; Ferreira, P.J.; Vieira, M.F. Seedless Cu Electroplating on Ru-W Thin Films for Metallisation of Advanced Interconnects. Int. J. Mol. Sci. 2022, 23, 1891. https://doi.org/10.3390/ijms23031891
Santos RF, Oliveira BMC, Savaris LCG, Ferreira PJ, Vieira MF. Seedless Cu Electroplating on Ru-W Thin Films for Metallisation of Advanced Interconnects. International Journal of Molecular Sciences. 2022; 23(3):1891. https://doi.org/10.3390/ijms23031891
Chicago/Turabian StyleSantos, Rúben F., Bruno M. C. Oliveira, Liliane C. G. Savaris, Paulo J. Ferreira, and Manuel F. Vieira. 2022. "Seedless Cu Electroplating on Ru-W Thin Films for Metallisation of Advanced Interconnects" International Journal of Molecular Sciences 23, no. 3: 1891. https://doi.org/10.3390/ijms23031891