Journal of the Microelectronics and Packaging Society (마이크로전자및패키징학회지)

The Korean Microelectronics and Packaging Society (한국마이크로전자및패키징학회)
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Cu Thickness Effects on Bonding Characteristics in Cu-Cu Direct Bonds

Cu 두께에 따른 Cu-Cu 열 압착 웨이퍼 접합부의 접합 특성 평가

  • 김재원 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • 정명혁 (안동대학교 신소재공학부 청정에너지소재기술연구센터) ;
  • ;
  • ;
  • ;
  • 이학주 (한국기계연구원 나노융합기계연구본부) ;
  • 현승민 (한국기계연구원 나노융합기계연구본부) ;
  • 박영배 (안동대학교 신소재공학부 청정에너지소재기술연구센터)
  • Received : 2010.12.10
  • Accepted : 2010.12.23
  • Published : 2010.12.30
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Abstract

Cu-Cu thermo-compression bonding process was successfully developed as functions of the deposited Cu thickness and $Ar+H_2$ forming gas annealing conditions before and after bonding step in order to find the low temperature bonding conditions of 3-D integrated technology where the interfacial toughness was measured by 4-point bending test. Pre-annealing with $Ar+H_2$ gas at $300^{\circ}C$ is effective to achieve enough interfacial adhesion energy irrespective of Cu film thickness. Successful Cu-Cu bonding process achieved in this study results in delamination at $Ta/SiO_2$ interface rather than Cu/Cu interface.

3차원 TSV 접합 시접합 두께 및 전, 후 추가 공정 처리가 Cu-Cu 열 압착 접합에 미치는 영향을 알아보기 위해 0.25, 0.5, 1.5, 3.0 um 두께로 Cu 박막을 제작한 후 접합 전 $300^{\circ}C$에서 15분간 $Ar+H_2$, 분위기에서 열처리 후 $300^{\circ}C$에서 30분 접합 후 후속 열처리 효과를 실시하여 계면접착에너지를 4점굽힘 시험법을 통해 평가하였다. FIB 이미지 확인 결과 Cu 두께에 상관없이 열 압착 접합이 잘 이루어져 있었다. 계면접착에너지 역시 두께에 상관없이 $4.34{\pm}0.17J/m^2$ 값을 얻었으며, 파괴된 계면을 분석 한 결과 $Ta/SiO_2$의 약한 계면에서 파괴가 일어났음을 확인하였다.

Keywords

References

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