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Effects of Wet Chemical Treatment and Thermal Cycle Conditions on the Interfacial Adhesion Energy of Cu/SiNx thin Film Interfaces

습식표면처리 및 열 사이클에 따른 Cu/SiNx 계면접착에너지 평가 및 분석

  • Jeong, Minsu (School of Materials Science and Engineering, Andong National University) ;
  • Kim, Jeong-Kyu (School of Materials Science and Engineering, Andong National University) ;
  • Kang, Hee-Oh (National Nanofab Center) ;
  • Hwang, Wook-Jung (National Nanofab Center) ;
  • Park, Young-Bae (School of Materials Science and Engineering, Andong National University)
  • 정민수 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 김정규 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 강희오 (나노종합기술원) ;
  • 황욱중 (나노종합기술원) ;
  • 박영배 (안동대학교 신소재공학부 청정에너지소재기술연구센터)
  • Received : 2014.02.18
  • Accepted : 2014.03.28
  • Published : 2014.03.30

Abstract

Effects of wet chemical treatment and thermal cycle conditions on the quantitative interfacial adhesion energy of $Cu/SiN_x$ thin film interfaces were evaluated by 4-point bending test method. The test samples were cleaned by chemical treatment after Cu chemical-mechanical polishing (CMP). The thermal cycle test between Cu and $SiN_x$ capping layer was experimented at the temperature, -45 to $175^{\circ}C$ for 250 cycles. The measured interfacial adhesion energy increased from 10.57 to $14.87J/m^2$ after surface chemical treatment. After 250 thermal cycles, the interfacial adhesion energy decreased to $5.64J/m^2$ and $7.34J/m^2$ for without chemical treatment and with chemical treatment, respectively. The delaminated interfaces were confirmed as $Cu/SiN_x$ interface by using the scanning electron microscope and energy dispersive spectroscopy. From X-ray photoelectron spectroscopy analysis results, the relative Cu oxide amounts between $SiN_x$ and Cu decreased by chemical treatment and increased after thermal cycle. The thermal stress due to the mismatch of thermal expansion coefficient during thermal cycle seemed to weaken the $Cu/SiN_x$ interface adhesion, which led to increased CuO amounts at Cu film surface.

반도체 미세구리배선 적용을 위하여 구리배선의 습식 표면처리 및 열 사이클에 따른 구리 박막과 실리콘질화막 도포층 사이의 계면접착에너지를 4점굽힘시험을 통해 정량적으로 평가하였다. 구리배선을 화학적 기계적 연마한 후 습식 표면처리를 통하여 구리 박막과 실리콘질화막의 계면접착에너지는 $10.57J/m^2$에서 $14.87J/m^2$로 증가하였다. $-45{\sim}175^{\circ}C$범위에서 250사이클 후, 표면처리를 하지 않은 시편의 계면접착에너지는 $5.64J/m^2$으로, 표면처리를 한 시편은 $7.34J/m^2$으로 감소하였으며, 모든 시편의 박리계면은 구리 박막과 실리콘질화막 계면으로 확인되었다. X-선 광전자 분광법으로 계면 결합 상태를 분석한 결과, 화학적 기계적 연마 공정 후 구리배선의 표면 산화물이 습식표면처리에 의해 효과적으로 제거된 것을 확인하였다. 또한, 열 사이클 처리동안, 구리 박막과 실리콘질화막의 큰 열 팽창 계수 차이로 인한 열응력으로 인하여 구리 박막과 실리콘질화막 계면이 취약해지고, 계면을 통한 산소유입에 따른 구리 산화층이 증가하여 계면접착에너지가 저하된 것으로 판단된다.

Keywords

References

  1. T. C. Wang, Y. L. Cheng, Y. L. Wang, T. E. Hsieh, G. J. Hwang, 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. Eun-Jung Jang, Seungmin Hyun, Hak-Joo Lee, and Young-Bae 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
  3. M.H. Lin, Y.L. Lin, K.P. Chang, K.C. Su, Tahui 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
  4. S. M. Yi, C. M. Shim, H. C. Lee, J. W. Han, K. H. Kim, and Y. C. Joo, "Effect of capping layer and post-CMP surface treatments on adhesion between damascene Cu and capping layer for ULSI interconnects", Microelectron. Eng., 85, 621 (2008). https://doi.org/10.1016/j.mee.2007.11.006
  5. Ryan P. Birringer, Roey Shaviv, Paul R. Besser, and Reinhold H. Dauskardt, "Environmentally assisted debonding of copper/ barrier interfaces" Acta Mater., 60, 2219 (2012). https://doi.org/10.1016/j.actamat.2012.01.007
  6. Wu ZhenYu, Yang YinTang, Chai ChangChun, Li YueJin, Wang JiaYou, Liu Jing, Liu Bin, "Temperature-dependent stress-induced voiding in dual-damascene Cu interconnects" Microelectron. Reliab., 48, 578 (2008). https://doi.org/10.1016/j.microrel.2007.12.001
  7. Jong-Min Paik, Hyun Park, Young-Chang Joo, "Effect of low-k dielectric on stress and stress-induced damage in Cu interconnects", Microelectron. Eng., 71, 348 (2004). https://doi.org/10.1016/j.mee.2004.02.094
  8. P. Agrawal, K. Conlon, K.J. Bowman, C.T. Sun, F.R. Cichocki JR, K.P, "Thermal residual stresses in co-continuous composites", Acta Mater., 51, 1143 (2003). https://doi.org/10.1016/S1359-6454(02)00519-0
  9. E.J. Cheng, Y.-L. Shen, "Thermal expansion behavior of through-silicon-via structures in three-dimensional microelectronic packaging", Microelectron. Reliab., 52, 534 (2012). https://doi.org/10.1016/j.microrel.2011.11.001
  10. Jeong-Kyu Kim, Hee-Oh Kang, Wook-Jung Hwang, Jun-Mo Yang, and Young-Bae 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
  11. Jesu's Carrillo-Lo'pez and Arturo Morales-Acevedo, "Characterization of the oxidation rate of densified SiN thin films by Auger and infrared absorption spectroscopies", Thin Solid Films, 311, 38 (1997). https://doi.org/10.1016/S0040-6090(97)00442-2
  12. R. H. Dauskardt, M. Lane, Q. Ma and N. Krishna, "Adhesion and debonding of multi-layer thin film structures", Eng Fract. Mech., 61, 141 (1998). https://doi.org/10.1016/S0013-7944(98)00052-6
  13. J. W. Kim, K. S. Kim, H. J. Lee, H. Y. Kim, Y. B. Park and S. M. Hyun, "Characterization and observation of Cu-Cu Thermo-Compression Bonding using 4-point bending test system", J. Microelectron. Packag. Soc., 18 (4), 11 (2011).
  14. J. K. Kim, E. K. Lee, M. S. Kim, J. H. Lim, K. H. Lee and Y. B. Park, "Interfacial Adhesion Energy of Ni-P Electrolessplating Contact for Buried Contact Silicon Solar Cell using 4-point Bending Test System", J. Microelectron. Packag. Soc. 19(1), 55 (2012). https://doi.org/10.6117/kmeps.2012.19.1.055
  15. P. G. Charalambides, J. Lund, A. G. Evans and R. M. McMeeking, "A Test Specimen for Determining the Fracture Resistance of Bimaterial Interfaces", J. Appl. Mech., 111, 77 (1989).
  16. T. Scherban. Sun, J. Blaine. Block. Jin and Adideh, "Interfacial Adhesion of Copper-Low k Interconnects", Proc. International Interconnect Tech. conference(IITC), Burlingame, 257, IEEE Components (2001).
  17. 정민수, 김정규, 강희오, 양준모, 황욱중, 박영배, "미세구리배선 적용을 위한 열처리 및 고온다습조건에서의 Cu capping layer 계면신뢰성 평가" (in Korean), 한국반도체학술대회, 20 (2013).
  18. I. Platzman, R. Brener, H. Haick, and R. Tannenbaum, "Oxidation of Polycrystalline Copper Thin Films at Ambient Conditions", J. Phys. Chem., C112, 1101 (2008).
  19. L. De Los Santos Valladares, D. Hurtado Salinas, A. Bustamante Dominguez, D. Acosta Najarro, S.I. Khondaker, T. Mitrelias, C.H.W. Barnes, J. Albino Aguiar, and Y. Majima, "Crystallization and electrical resistivity of Cu2O and CuO obtained by thermal oxidation of Cu thin films on SiO2/Si substrates", Thin Solid Films, 520, 6368 (2012). https://doi.org/10.1016/j.tsf.2012.06.043
  20. Laura Frisk and Kati Kokko, "The effects of chip and substrate thickness on the reliability of ACA bonded flip chip joints", Soldering & Surface Mount Tech., 18(4) 28 (2006). https://doi.org/10.1108/09540910610717884
  21. Xu Chen, Jun Zhang, Chunlei Jiao, Yanmin Liu, "Effects of different bonding parameters on the electrical performance and peeling strengths of ACF interconnection", Microelectron. Reliab., 46, 774 (2006). https://doi.org/10.1016/j.microrel.2005.07.115

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