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Characterization of Interfacial Adhesion of Cu-Cu Bonding Fabricated by Thermo-Compression Bonding Process

열가압 접합 공정으로 제조된 Cu-Cu 접합의 계면 접합 특성 평가

  • Kim, Kwang-Seop (Nano Convergence and Manufacturing Systems Research Division, KIMM) ;
  • Lee, Hee-Jung (Nano Convergence and Manufacturing Systems Research Division, KIMM) ;
  • Kim, Hee-Yeoun (NEMS/Bio Team, National Nanofab Center) ;
  • Kim, Jae-Hyun (Nano Convergence and Manufacturing Systems Research Division, KIMM) ;
  • Hyun, Seung-Min (Nano Convergence and Manufacturing Systems Research Division, KIMM) ;
  • Lee, Hak-Joo (Nano Convergence and Manufacturing Systems Research Division, KIMM)
  • 김광섭 (한국기계연구원 나노융합.생산시스템 연구본부) ;
  • 이희정 (한국기계연구원 나노융합.생산시스템 연구본부) ;
  • 김희연 (국가나노종합팹센터 넴스바이오팀) ;
  • 김재현 (한국기계연구원 나노융합.생산시스템 연구본부) ;
  • 현승민 (한국기계연구원 나노융합.생산시스템 연구본부) ;
  • 이학주 (한국기계연구원 나노융합.생산시스템 연구본부)
  • Received : 2009.12.31
  • Accepted : 2010.06.01
  • Published : 2010.07.01

Abstract

Four-point bending tests were performed to investigate the interfacial adhesion of Cu-Cu bonding fabricated by thermo-compression process for three dimensional packaging. A pair of Cu-coated Si wafers was bonded under a pressure of 15 kN at $350^{\circ}C$ for 1 h, followed by post annealing at $350^{\circ}C$ for 1 h. The bonded wafers were diced into $30\;mm\;{\times}\;3\;mm$ pieces for the test. Each specimen had a $400-{\mu}m$-deep notch along the center. An optical inspection module was installed in the testing apparatus to observe crack initiation at the notch and crack propagation over the weak interface. The tests were performed under a fixed loading speed, and the corresponding load was measured. The measured interfacial adhesion energy of the Cu-to-Cu bonding was $9.75\;J/m^2$, and the delaminated interfaces were analyzed after the test. The surface analysis shows that the delamination occurred in the interface between $SiO_2$ and Ti.

Keywords

Adhesion;Four-Point Bending Test;Cu-Cu Bonding;Thermo-compression Bonding Process

Acknowledgement

Grant : 차세대 반도체 MCP 핵심기술 개발 사업

Supported by : 지식경제부, 산업기술연구회

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