Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Bending Fatigue Reliability Improvements of Cu Interconnects on Flexible Substrates through Mo-Ti Alloy Adhesion Layer

Mo-Ti 합금 접착층을 통한 유연 기판 위 구리 배선의 기계적 신뢰성 향상 연구

  • Lee, Young-Joo (Department of Materials Science & Engineering, Seoul National University) ;
  • Shin, Hae-A-Seul (Department of Materials Science & Engineering, Seoul National University) ;
  • Nam, Dae-Hyun (Department of Materials Science & Engineering, Seoul National University) ;
  • Yeon, Han-Wool (Department of Materials Science & Engineering, Seoul National University) ;
  • Nam, Boae (LG Display Research and Development Center, LG Display Co. Ltd.) ;
  • Woo, Kyoohee (Advanced Manufacturing Systems Research Division, Korea Institute of Machinery and Materials) ;
  • Joo, Young-Chang (Department of Materials Science & Engineering, Seoul National University)
  • Received : 2014.12.01
  • Accepted : 2015.01.26
  • Published : 2015.03.30
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Abstract

Bending fatigue characteristics of Cu films and $8{\mu}m$ width Cu interconnects on flexible substrates were investigated, and fatigue reliability improvement was achieved through Mo-Ti alloy adhesion layer. Tensile bending fatigue reliability of Cu interconnects is 3 times lower than that of Cu films, and even compressive bending fatigue reliability of Cu interconnects is 6 times lower than that of Cu films. From these results, mechanical crack formation could be fatal in Cu interconnects. With Mo-Ti adhesion layer, fatigue reliability of Cu films and interconnects were enhanced due to the increase of adhesion strength and the suppression of slip induced crack initiation.

유연 기판에 증착된 구리 박막과 구리 배선의 기계적 피로 현상에 대해 조사하고, 몰리브덴-티타늄 합금 접착 층을 이용해 피로 신뢰성을 향상시키는 연구를 진행하였다. 구리 배선의 경우 구리 박막에 비해 인장 굽힘 피로수명이 약 3배, 압축 굽힘 피로수명은 약 6배 가량 감소하는 것으로 측정되었으며, 기계적 균열 생성에 의한 파괴가 더욱 치명적으로 작용할 수 있다. 몰리브덴-티타늄 접착층이 있을 경우, 구리 배선의 피로수명이 인장과 압축 굽힘 조건 모두 향상되는 결과를 나타냈으며, 이는 접착층에 의한 계면 접착력 상승 효과와 더불어 구리층의 미끄럼 현상을 억제했기 때문으로 추측된다.

Keywords

References

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