Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Bonding Strength Evaluation of Copper Bonding Using Copper Nitride Layer

구리 질화막을 이용한 구리 접합 구조의 접합강도 연구

  • Seo, Hankyeol (Nano-IT Convergence Engineering, Graduate School of Nano-IT-Design Convergence, Seoul National University of Science and Technology) ;
  • Park, Haesung (Department of Mechanical Engineering, Seoul National University of Science and Technology) ;
  • Kim, Gahui (School of Materials Science and Engineering, Andong National University) ;
  • Park, Young-Bae (School of Materials Science and Engineering, Andong National University) ;
  • Kim, Sarah Eunkyung (Nano-IT Convergence Engineering, Graduate School of Nano-IT-Design Convergence, Seoul National University of Science and Technology)
  • 서한결 (서울과학기술대학교 나노IT디자인융합대학원 나노IT융합공학전공) ;
  • 박해성 (서울과학기술대학교 일반대학원 기계공학과) ;
  • 김가희 (안동대학교 신소재공학부) ;
  • 박영배 (안동대학교 신소재공학부) ;
  • 김사라은경 (서울과학기술대학교 나노IT디자인융합대학원 나노IT융합공학전공)
  • Received : 2020.08.05
  • Accepted : 2020.08.31
  • Published : 2020.09.30
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Abstract

The recent semiconductor packaging technology is evolving into a high-performance system-in-packaging (SIP) structure, and copper-to-copper bonding process becomes an important core technology to realize SIP. Copper-to-copper bonding process faces challenges such as copper oxidation and high temperature and high pressure process conditions. In this study, the bonding interface quality of low-temperature copper-to-copper bonding using a two-step plasma treatment was investigated through quantitative bonding strength measurements. Our two-step plasma treatment formed copper nitride layer on copper surface which enables low-temperature copper bonding. The bonding strength was evaluated by the four-point bending test method and the shear test method, and the average bonding shear strength was 30.40 MPa, showing that the copper-to-copper bonding process using a two-step plasma process had excellent bonding strength.

최근 참단 반도체 패키징 기술은 고성능 SIP(system in packaging) 구조로 발전해 가고 있고, 이를 실현시키기 위해서 구리 대 구리 접합은 가장 핵심적인 기술로 대두되고 있다. 구리 대 구리 접합 기술은 아직 구리의 산화 특성과 고온 및 고압력 공정 조건, 등 해결해야 할 문제점들이 남아 있다. 본 연구에서는 아르곤과 질소를 이용한 2단계 플라즈마 공정을 이용한 저온 구리 접합 공정의 접합 계면 품질을 정량적 접합 강도 측정을 통하여 확인하였다. 2단계 플라즈마 공정은 구리 표면에 구리 질화막을 형성하여 저온 구리 접합을 가능하게 한다. 구리 접합 후 접합 강도 측정은 4점 굽힘 시험법과 전단 시험법으로 수행하였으며, 평균 접합 전단 강도는 30.40 MPa로 우수한 접합 강도를 보였다.

Keywords

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