Electrical characteristics of ruthenium lines with a cross-sectional area less than 1000 nm2

Cover Page

Cite item

Full Text

Open Access Open Access
Restricted Access Access granted
Restricted Access Subscription Access

Abstract

As the IC scales, it becomes necessary to form lines with a width of less than 20 nm at the lower levels of the metallization system. Copper at such sizes ceases to meet the requirements for RC delays and resistance to electromigration. Therefore, it is necessary to look for alternative materials to replace copper, which will provide higher resistance to electromigration and lower resistance of the lines. The most promising candidate is Ru. In this study, test structures with ruthenium lines were obtained. For this purpose, such methods of creating structures as plasma-stimulated deposition from the gas phase, plasma-stimulated atomic layer deposition, magnetron sputtering, electron beam lithography, and plasma chemical etching were used. Spectroscopic ellipsometry and scanning electron microscopy were used to control the creation and investigation of the resulting structures. The electrical characteristics of the structures were measured and tested.

Full Text

Restricted Access

About the authors

O. G. Glaz

Kurchatov Institute; Moscow Power Engineering Institute

Author for correspondence.
Email: glaz@ftian.ru
Russian Federation, Moscow; Moscow

A. E. Rogozhin

Kurchatov Institute

Email: rogozhin@ftian.ru
Russian Federation, Moscow

References

  1. Kapur P., McVittie J.P., Saraswat K.C. Technology and reliability constrained future copper interconnects. I. Resistance modeling // IEEE Transactions on Electron Devices. – 2002. – Т. 49. – № 4. – С. 590–597.
  2. Gall D. The search for the most conductive metal for narrow interconnect lines // Journal of Applied Physics. – 2020. – Т. 127. – № 5.
  3. Kamineni V., Raymond M., Siddiqui S., Mont F., Tsai S., Niu C., L’Herron B. IEEE International Interconnect Technology Conference / Advanced Metallization Conference (IITC, AMC) // IEEE International Interconnect Technology Conference IITC. – Ieee, 2016. – С. 105.
  4. Wen L.G., Cui Y., Kuwahara Y., Mori K., Yamashita H. Atomic layer deposition of ruthenium with TiN interface for sub-10 nm advanced interconnects beyond copper // ACS applied materials & interfaces. – 2016. – Т. 8. – № 39. – С. 26119–26125.
  5. Fan S.S.C., Chen J.H.C., Kamineni V.K., Zhang X., Raymond M., and Labelle C. IEEE International Interconnect Technology Conference (IITC) // IEEE. – 2017. – Т. 2017. – С. 1–3.
  6. Nogami T., Patlolla R., Kelly J., Briggs B., Huang H., Demarest J., Paruchuri V. Cobalt/copper composite interconnects for line resistance reduction in both fine and wide lines // 2017 IEEE International Interconnect Technology Conference (IITC). – IEEE, 2017. – С. 1–3.
  7. Wan D., Paolillo S., Rassoul N., Kotowska B.K., Blanco V., Adelmann C., Lazzarino F., Ercken M. Subtractive etch of ruthenium for sub-5nm interconnect // 2018 IEEE International Interconnect Technology Conference (IITC). – IEEE, 2018. – С. 10–12.
  8. Van der Veen M.H., Heylen N., Varela Pedreira O., Ciofi I., Decoster S., Gonzalez V. Vega, Jourdan N., Struyf H., Croes K., Wilson C.J., Tőkei Zs. Damascene benchmark of Ru, Co and Cu in scaled dimensions // 2018 IEEE International Interconnect Technology Conference (IITC). – IEEE, 2018. – С. 172–174.

Supplementary files

Supplementary Files
Action
1. JATS XML
2. Fig. 1. Schematic representation of test structures for resistance measurement

Download (71KB)
3. Fig. 2. Resistive mask after thermal drying (left) and vacuum evacuation (right)

Download (317KB)
4. Fig. 3. Dimensions of the final structure

Download (264KB)
5. Fig. 4. SEM image of the structure at an angle. The thickness of the lines is 30 nm taking into account the 45° tilt angle correction

Download (180KB)
6. Fig. 5. General view of the structure with lines from above

Download (444KB)
7. Fig. 6. Image of the structure lines with a width of 10 nm

Download (363KB)
8. Fig. 7. Image of the structure lines with a width of 15 nm

Download (416KB)
9. Fig. 8. Places where lines join the sites

Download (331KB)
10. Fig. 9. Image of the structure lines with a width of 20 nm

Download (240KB)
11. Fig. 10. Cross sections of 20 nm wide lines

Download (170KB)
12. Fig. 11. SEM images of the resist lithographic mask (left) and ruthenium lines after etching (right)

Download (156KB)
13. Fig. 12. Process of ruthenium structure SAC acquisition

Download (154KB)
14. Fig. 13. SAC of ruthenium structure with 15 nm wide lines

Download (234KB)
15. Fig. 14. Dependence of the average resistivity of the line on the cross-sectional area

Download (73KB)
16. Fig. 15. Dependence of the average line resistivity on the line width for different ruthenium thicknesses [7]. The obtained results are marked with black dots

Download (204KB)
17. Fig. 16. Dependence of the average resistivity of the line on the cross-sectional area [8]. The obtained results are marked with black dots

Download (203KB)
18. Fig. 17. Cross-section of the original sample. The ruthenium layer has a columnar structure, which has a bad effect on its electrical conductivity

Download (317KB)

Copyright (c) 2025 Russian Academy of Sciences