Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Electroless Plating of Co-Alloy Thin Films using Alkali-Free Chemicals

Alkali 물질이 포함되지 않은 화학물질을 이용한 Co 합금박막의 무전해도금

  • Kim, Tae Ho (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University) ;
  • Yun, Hyeong Jin (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University) ;
  • Kim, Chang-Koo (Department of Chemical Engineering, Division of Energy Systems Research, Ajou University)
  • 김태호 (아주대학교 에너지시스템학부 화학공학전공) ;
  • 윤형진 (아주대학교 에너지시스템학부 화학공학전공) ;
  • 김창구 (아주대학교 에너지시스템학부 화학공학전공)
  • Received : 2007.06.13
  • Accepted : 2007.07.06
  • Published : 2007.12.31
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Abstract

Electroless plating of Co-alloy thin films as capping layers for Cu interconnection has been investigated using alkali-free precursors such as $(NH_4)_2Co(SO_4)_2{\cdot}6H_2O$, $(NH_4)_2WO_4$, $(NH_4)H_2PO_4$, etc. The characteristics of the Co-alloy thin films were discussed by analyses of the effects of pH, Co-precursor concentration, and deposition temperature on the thickness and surface morphology of the films. The thickness of the Co-alloy thin films increased with increasing pH, Co-precursor concentration, and deposition temperature, similarly to the results of electroless plating of Co-alloy thin films using alkali-containing chemicals. The SEM images of the surface of the Co-alloy thin films showed that the proper ranges of pH and deposition temperature were 8.5~9.5 and $75{\sim}85^{\circ}C$, respectively. This work found a feasibility that Co-alloy thin films as capping layers for Cu interconnection could be electroless plated using alkali-free chemicals.

Alkali 물질이 포함되지 않은 $(NH_4)_2Co(SO_4)_2{\cdot}6H_2O$, $(NH_4)_2WO_4$, $(NH_4)H_2PO_4$ 등의 전구체를 사용하여 구리배선의 보호막 제조를 위한 Co 합금박막의 무전해도금을 수행하였다. pH, Co 전구체 농도, 증착온도 등의 공정변수들의 변화에 대한 Co 합금박막의 두께와 표면형상을 살펴봄으로써 이들 공정변수가 alkali 물질이 포함되지 않은 화학물질로 무전해도금된 Co 합금박막의 특성에 끼치는 영향을 살펴보았다. pH, Co 전구체 농도, 증착온도가 증가할수록 Co 합금 박막의 두께가 증가하였고 이는 alkali 물질이 포함된 Co 합금박막의 무전해도금 결과와 비슷하다. SEM(scanning electron microscopy)을 이용한 Co 합금박막의 표면형상 관측 결과, 본 연구에서 사용된 공정조건에서 Co 합금박막의 무전해도금을 위한 적절한 pH와 온도의 범위가 각각 8.5~9.5와 $75{\sim}85^{\circ}C$임을 얻었다. 본 연구를 통하여 alkali 물질이 포함되지 않은 화학물질을 이용한 무전해도금으로 구리배선의 보호막 제조용 Co 합금박막의 증착이 가능함을 확인하였다.

Keywords

Acknowledgement

Supported by : 한국과학재단

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