Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
권호 표지
DOI QR코드

DOI QR Code

Effect of Co Interlayer on the Interfacial Reliability of SiNx/Co/Cu Thin Film Structure for Advanced Cu Interconnects

미세 Cu 배선 적용을 위한 SiNx/Co/Cu 박막구조에서 Co층이 계면 신뢰성에 미치는 영향 분석

  • Lee, Hyeonchul (JCET STATS ChipPAC Korea LTD.) ;
  • Jeong, Minsu (Amkor Technology Korea Inc.) ;
  • Kim, Gahui (School of Materials Science and Engineering, Andong National University) ;
  • Son, Kirak (School of Materials Science and Engineering, Andong National University) ;
  • Park, Young-Bae (School of Materials Science and Engineering, Andong National University)
  • 이현철 ((주)제이셋스태츠칩팩코리아) ;
  • 정민수 ((주)앰코테크놀로지 코리아) ;
  • 김가희 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 손기락 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 박영배 (안동대학교 신소재공학부 청정에너지소재기술연구센터)
  • Received : 2020.08.06
  • Accepted : 2020.09.25
  • Published : 2020.09.30
Download PDF
⟨ Previous Next ⟩

Abstract

The effect of Co interlayer on the interfacial reliability of SiNx/Co/Cu thin film structure for advanced Cu interconnects was systematically evaluated by using a double cantilever beam test. The interfacial adhesion energy of the SiNx/Cu thin film structure was 0.90 J/㎡. This value of the SiNx/Co/Cu thin film structure increased to 9.59 J/㎡.Measured interfacial adhesion energy of SiNx/Co/Cu structure was around 10 times higher than SiNx/Cu structure due to CoSi2 reaction layer formation at SiNx/Co interface, which was confirmed by X-ray photoelectron spectroscopy analysis. The interfacial adhesion energy of SiNx/Co/Cu structure decreased sharply after post-annealing at 200℃ for 24 h due to Co oxidation at SiNx/Co interface. Therefore, it is required to control the CoO and Co3O4 formation during the environmental storage of the SiNx/Co/Cu thin film to achieve interfacial reliability for advanced Cu interconnections.

비메모리 반도체 미세 Cu배선의 전기적 신뢰성 향상을 위해 SiNx 피복층(capping layer)과 Cu 배선 사이 50 nm 두께의 Co 박막층 삽입이 계면 신뢰성에 미치는 영향을 double-cantilever beam (DCB) 접착력 측정법으로 평가하였다. DCB 평가 결과 SiNx/Cu 구조는 계면접착에너지가 0.90 J/㎡이었으나 SiNx/Co/Cu 구조에서는 9.59 J/㎡으로 SiNx/Cu 구조보다 약 10배 높게 측정되었다. 대기중에서 200℃, 24시간 동안 후속 열처리 진행한 결과 SiNx/Cu 구조는 0.93 J/㎡으로 계면접착에너지의 변화가 거의 없는 것으로 확인되었으나 SiNx/Co/Cu 구조에서는 2.41 J/㎡으로 열처리 전보다 크게 감소한 것을 확인하였다. X-선 광전자 분광법 분석 결과 SiNx/Cu 도금층 사이에 Co를 증착 시킴으로써 SiNx/Co 계면에 CoSi2 반응층이 형성되어 SiNx/Co/Cu 구조의 계면접착에너지가 매우 높은 것으로 판단된다. 또한 대기중 고온에서 장시간 후속 열처리에 의해 SiNx/Co 계면에 지속적으로 유입된 산소로 인한 Co 산화막 형성이 계면접착에너지 저하의 주요인으로 판단된다.

Keywords

References

  1. T. C. Wang, Y. L. Cheng, Y. L. Wang, T. E. Hsieh, G. J. Hwang, and C. F. Chen, "Comparison of characteristics and integration of copper diffusion-barrier dielectrics", Thin Solid Films, 498, 36 (2006). https://doi.org/10.1016/j.tsf.2005.07.059
  2. J. K. Kim, H. O. Kang, W. J. Hwang, J. M. Yang, and Y. B. Park, "Effect of Post-Chemical-Mechanical Polishing Surface Treatments on the Interfacial Adhesion Energy between Cu and a Capping Layer", Jpn. J. Appl. Phys., 52, 10MC05 (2013). https://doi.org/10.7567/JJAP.52.10MC05
  3. M. S. Jeong, J. K. Kim, H. O. Kang, W. J. Hwang, and Y. B. Park, "Effects of Wet Chemical Treatment and Thermal Cycle Conditions on the Interfacial Adhesion Energy of Cu/$SiN_x$ thin Film Interfaces", J. Microelectric. Pack. Soc., 21(1), 45 (2014).
  4. E. J. Jang, S. Hyun, H. J. Lee, and Y. B. Park, "Effect of Wet Pretreatment on Interfacial Adhesion Energy of Cu-Cu Thermocompression Bond for 3D IC Packages", J. Electron. Mater., 38(12), 2449 (2009). https://doi.org/10.1007/s11664-009-0942-9
  5. M. H. Lin, Y. L. Lin, K. P. Chang, K. C. Su, and T. Wang, "Copper interconnect electromigration behaviors in various structures and lifetime improvement by cap/dielectric interface treatment", Microelectron. Reliab., 45, 1061 (2005). https://doi.org/10.1016/j.microrel.2004.11.055
  6. H. W. Yao, K. Y. Yiang, P. Justison, M. Rayasam, O. Aubel, and J. Poppe, "Stress migration model for Cu interconnect reliability analysis", J. Appl. Physic., 110, 073504 (2001). https://doi.org/10.1063/1.3644972
  7. C. K. Hu and R. Rosenberg, "Capping Layer Effects on Electromigration in Narrow Cu Lines", AIP Conference Proceedings, 741(1), 97 (2004).
  8. J. R. Lloyd, M. W. Lane, E. G. Liniger, C. K. Hu, T. M. Shaw, and R. Rosenberg, "Electromigration and adhesion", IEEE Transactions on Dev. & Mater. Reliab., 5(1), 113 (2005). https://doi.org/10.1109/TDMR.2005.846308
  9. C. C. Yang, P. Flaitz, B. Li, F. Chen, C. Christiansen, S. Y. Lee, P. Ma, and D. Edelstein, "Co capping layer Cu/low-k interconnect", Microelectronic Enginnering, 92, 79 (2012). https://doi.org/10.1016/j.mee.2011.04.017
  10. C. C. Yang, B. Li, H. Shobha, S. Nguyen, A. Grill, W. Ye, J. AuBuchon, M. Shek, and D. Edelstein, "In Situ Co/SiC(N,H) Capping Layers for Cu/Low-k Interconnects", Electron. Dev. Lett., 33(4), 588 (2012). https://doi.org/10.1109/LED.2012.2183850
  11. M. W. Lane, E. G. Liniger, and J. R. Lloyd, "Relationship between interfacial adhesion and electromigration in Cu metallization", J. Appl. Phys., 98, 1417 (2003).
  12. D. Priyadarshini, S. Nguyen, H. Shobha, S. Cohen, T. Shaw, E. Liniger, C. K. Hu, C. Parks, E. Adams, J. Burnham, A. H. Simon, G. Bonilla, A. Grill, D. Canaperi, D. Edelstein, D. Collins, M. Balseanu, M. Stolfi, and J. Ren, K. Shah, "Advanced metal and dielectric barrier cap films for Cu low k interconnects", Proc. IEEE International interconnect Technology Conference Advanced Metallization Conference, San Jose, CA, USA, 185 (2014).
  13. M. Lane, "Interface fracture", Annu. Rev. Mater. Res., 33, 29 (2003). https://doi.org/10.1146/annurev.matsci.33.012202.130440
  14. I. Lee, S. Kim, J. Yun, I. Park, and T. S. Kim, "Interfacial toughening of solute on processed Ag nanoparticle thin films by organic residuals", Nanotechnology, 23, 485704 (2012). https://doi.org/10.1088/0957-4484/23/48/485704
  15. S. I. Raider, R. Flitsch, J. A. Aboaf, and W. A. Pliskin, "Surface Oxidation of Silicon Nitride Film", J. Electrochem. Soc., 123(4), 560 (1976). https://doi.org/10.1149/1.2132877
  16. H. H. Kim, W. Han, H. S. Lee, B. G. Min, and B. J. Kim, "Preparation and characterization of silicon nitride (Si N)-coatedcarbon fibers and their effects on thermal properties in composites", Materials Science and Engineering: B, 200, 132 (2015). https://doi.org/10.1016/j.mseb.2015.07.001
  17. I. Platzman, R. Brener, H. Haick, and R. Tannenbaum, "Oxidation of Polycrystalline Copper Thin Films at Ambient Conditions", J. Phys. Chem., C112, 1101 (2008).
  18. L. D. L. S. Valladares, D. H. Salinas, A. B. Dominguez, D. A. Najarro, S. I. Khondaker, T. Mitrelias, C. H. W. Barnes, J. A. Aguiar, and Y. Majima, "Crystallization and electrical resistivity of $Cu_2$O and CuO obtained by thermal oxidation of Cu thin films on $SiO_2$/Si substrates", Thin Solid Films, 520, 6368 (2012). https://doi.org/10.1016/j.tsf.2012.06.043
  19. J. J. Chang, C. P. Liu, T. E. Hsieh, and Y. L. Wang, "The study of diffusion and nucleation for $CoSi_2$ formation by oxidemediated cobalt silicidation", Surf. Coat. Technol., 200, 3314 (2006). https://doi.org/10.1016/j.surfcoat.2005.07.044
  20. A. Sharma, S. Tripathi, and T. Shripathi, "X-ray photoelectron study of annealed Co thin film on Si surface", Applied Surface Science, 256, 530 (2009). https://doi.org/10.1016/j.apsusc.2009.08.007
  21. T. Nguyen, H. L. Ho, D. E. Kotecki, and T. D. Nguyen, "Reaction study of cobalt and silicon nitride", J. Mater. Res., 8(9), 2354 (1993). https://doi.org/10.1557/JMR.1993.2354