3차원 적층 패키지를 위한 Cu/Ni/Au/Sn-Ag/Cu 미세 범프 구조의 열처리에 따른 금속간 화합물 성장 거동 분석
Intermetallic Compound Growth Characteristics of Cu/Ni/Au/Sn-Ag/Cu Micro-bump for 3-D IC Packages
0
조회
0
다운로드
7
인용
0
참고문헌
키워드
초록
3차원 적층 패키지를 위한Cu/Ni/Au/Sn-Ag/Cu 미세 범프의 열처리에 따른 금속간 화합물 성장 거동을 분석하기 위하여 in-situ SEM에서 135oC, 150oC, 170oC의 온도에서 실시간 열처리 실험을 진행하였다. 실험 결과 금속간 화합물의 성장 거동은 열처리시간이 경과함에 따라 시간의 제곱근에 직선 형태로 증가하였고, 확산에 의한 성장이 지배적인것을 확인 할 수 있었다. Ni/Au 층의 존재로 인해 Au의 확산으로 복잡한 구조의 금속간 화합물이 생성 된 것을 확인 할수 있다. 활성화 에너지는 Cu3Sn의 경우 0.69eV, (Cu,Ni,Au)6Sn5경우 0.84 eV로 Ni이 포함된 금속간 화합물이 더 높은것을 확인 하였으며, 확산 방지층 역할을 하는 Ni층에 의해 금속간 화합물 성장이 억제됨에 따라 신뢰성이 향상 될 것으로 사료된다.
Abstract
In-situ annealing tests of Cu/Ni/Au/Sn-Ag/Cu micro-bump for 3D IC package were performed in an scanning electron microscope chamber at 135-170oC in order to investigate the growth kinetics of intermetallic compound (IMC). The IMC growth behaviors of both Cu3Sn and (Cu,Ni,Au)6Sn5 follow linear relationship with the square root of the annealing time, which could be understood by the dominant diffusion mechanism. Two IMC phases with slightly different compositions, that is, (Cu,Aua)6Sn5 and (Cu,Aub)6Sn5 formed at Cu/solder interface after bonding and grew with increased annealing time. By the way, Cu3Sn and (Cu,Ni,Au)6Sn5 phases formed at the interfaces between Cu/(Cu,Au)6Sn5 and Ni/Sn, respectively, and both grew with increased annealing time. The activation energies for Cu3Sn and (Cu,Ni,Au)6Sn5 IMC growths during annealing were 0.69 and 0.84 eV, respectively, where Ni layer seems to serve as diffusion barrier for extensive Cu-Sn IMC formation which is expected to contribute to the improvement of electrical reliability of micro-bump.
참고문헌 (22)
- 이대현, "팔라듐 표면처리를 통한 Massive Spalling 현상의 억제", 대한금속·재료학회지, 48(11), pp.1041~1046 (2010), 대한금속·재료학회
- Sung-Cheol Park, "Effect of Annealing on the Interfacial Adhesion Energy between Electroless-Plated Ni and Polyimide", Metals and Materials International, 17(1), pp.111~115 (2011), 대한금속·재료학회
- Eun-Jung Jang, "Annealing Temperature Effect on the Cu-Cu Bonding Energy for 3D-IC Integration", Metals and Materials International, 17(1), pp.105~109 (2011), 대한금속·재료학회
- K. N. Chen, "Abnormal contact resistance reduction of bonded copper interconnects in threedimensional integration during current stressing", Appl.Phys. Lett, 86, pp.011903~ (2005)
- B. J. Kim, "Intermetallic Compound Growth and Reliability of Cu Pillar Bumps Under Current Stressing", J. Electron. Mater, 39, pp.2281~ (2010)
- G. T. Lim, "Temperature Effect on Intermetallic Compound Growth Kinetics of Cu Pillar", Sn Bumps, 2009, pp.38, 2228~
- M. H. Jeong, "Interfacial Reaction Effect on Electrical Reliability of Cu Pillar", Sn Bumps, 2010, pp.39, 2368~
- 김병준, "Microstructure Evolution in Cu Pillar", Eutectic SnPb Solder System during Isothermal Annealing, 2009, pp.15(5), 815~818[DOI]
- 임기태, "Cu pillar 범프 내의 금속간화합물 성장거동에 미치는 시효처리의 영향", 마이크로전자 및 패키징학회지, 14(4), pp.15~20 (2007), 한국마이크로전자및패키징학회
- 정명혁, "3차원 적층 패키지를 위한 Cu", thin Sn, 대한금속·재료학회지, pp.2011, 49(2)[DOI]
- J. W. Nah, "Electromigration in flip chip solder joints having a thick Cu column bump and a shallow solder interconnect", J. Appl. Phys., 100, pp.123513~ (2006)
- 김종웅, "Failure Mechanism of Pb-Bearing and Pb-Free Solder Joints under High-Speed Shear Loading", Metals and Materials International, 16(1), pp.7~12 (2010), 대한금속·재료학회
- 김정민, "Electrical Conductivity and Tensile Properties of Severely Cold-Worked Cu-P Based Alloy Sheets", Metals and Materials International, 16(4), pp.657~661 (2010), 대한금속·재료학회
- 김영민, "Mechanism of the Delayed Growth of Intermetallic Compound at the Interface between Sn-4.0Ag-0.5Cu and Cu-Zn Substrate", Electronic Materials Letters, 6(4), pp.151~154 (2010), 대한금속·재료학회
- B. H. Lee, "A Study on the Bonding Process of Cu Bump", Sn, J. Electrochem. Soc, pp.2010, 157[DOI]
- Y. S. Lai, "Electromigration Reliability and Morphologies of Cu Pillar Flip-Chip Solder Joints with Cu Substrate Pad Metallization", J. Elecron. Mater, 37, pp.1624~ (2008)
- 김성혁, "PCB 표면처리에 따른 Sn-1.2Ag-0.7Cu-0.4In 무연솔더 접합부의 기계적 신뢰성에 관한 연구", 마이크로전자 및 패키징학회지, 19(4), pp.57~64 (2012), 한국마이크로전자및패키징학회[DOI]
- C. W. Chang, "Kinetics of AuSn4 Migration in Lead-Free Solders", J. Elecron. Mater, 35, pp.11~ (2006)
- Y. Wang, "Effect of Intermetallic Formation on Electromigration Reliability of TSV-Microbump Joints in 3D Interconnect", 62th Electronic Components and Technology Conference(ECTC), San Diego, 319, IEEE CPMT (2012)
- H. T. Chen, "Cross-Interaction of Interfacial Reactions in Ni (Au", Ni, J. Elecron. Mater, pp.2007, 36[DOI]
- K. N. Tu, "Interdiffusion and Reaction in Bimetallic Cu-Sn Thin Films", Acta Metall, 21, pp.347~ (1973)
- M. H. Jeong, "Effects of annealing and current stressing on the intermetallic compounds growth kinetics of Cu", thin Sn, Microelectron. Eng, pp.2009, 89[DOI]