Ar-N2 플라즈마가 Cu 표면에 미치는 구조적 특성 분석
Structural Characteristics of Ar-N2 Plasma Treatment on Cu Surface
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Cu-Cu 웨이퍼 본딩 강도를 향상시키기 위한 Cu 박막의 표면처리 기술로 Ar-N2 플라즈마 처리 공정에 대해연구하였다. Ar-N2 플라즈마 처리가 Cu 표면의 구조적 특성에 미치는 영향을 X선 회절분석법, X선 광전자 분광법, 원자간력현미경을 이용하여 분석하였다. Ar 가스는 플라즈마 점화 및 이온 충격에 의한 Cu 표면의 활성화에 사용되고, N2 가스는 패시베이션(passivation) 층을 형성하여 -O 또는 -OH와 같은 오염으로부터 Cu 표면을 보호하기 위한 목적으로 사용되었다. Ar 분압이 높은 플라즈마로 처리한 시험편은 표면이 활성화되어 공정 이후 더 많은 산화가 진행되었고, N2 분압이 높은 플라즈마 시험편에서는 Cu-N 및 Cu-O-N과 같은 패시베이션 층과 함께 상대적으로 낮은 수치의 산화도가 관찰되었다. 본 연구에서는 Ar-N2 플라즈마 처리가 Cu 표면에서 Cu-O 형성 억제 반응에 기여하는 것을 확인할 수 있었으나 추가 연구를 통하여 질소 패시베이션 층이 Cu 웨이퍼 전면에 형성되기 위한 플라즈마 가스 분압 최적화를 진행하고자 한다.
Abstract
The effect of Ar-N2 plasma treatment on Cu surface as one of solutions to realize reliable Cu-Cu wafer bonding was investigated. Structural characteristic of Ar-N2 plasma treated Cu surface were analyzed using X-ray diffraction, X-ray photoelectron spectroscopy, atomic force microscope. Ar gas was used for a plasma ignition and to activate Cu surface by ion bombardment, and N2 gas was used to protect the Cu surface from contamination such as -O or -OH by forming a passivation layer. The Cu specimen under high Ar partial pressure plasma treatment showed more copper oxide due to the activation on Cu surface, while Cu surface after high N2 gas partial pressure plasma treatment showed less copper oxide due to the formation of Cu-N or Cu-O-N passivation layer. It was confirmed that nitrogen plasma can prohibit Cu-O formation on Cu surface, but nitrogen partial pressure in the Ar-N2 plasma should be optimized for the formation of nitrogen passivation layer on the entire surface of Cu wafer.
참고문헌 (18)
- C. S. Tan, "Wafer level 3-D ICs process technology", pp.1~11 (2009), Springer Science & Business Media, Springer
- C. T. Ko, "Low temperature bonding technology for 3D integration", Microelectronics Reliability, 52(2), pp.302~ (2012)
- S. E. Kim, "Wafer level Cu-Cu direct bonding for 3D integration", Microelectronic Engineering, 137(1), pp.158~ (2015)
- J. H. Lau, "Fan-out wafer-level packaging for Heterogenous Integration", IEEE Transactions on Components, Packaging and Manufacturing Technology, 8(9), pp.1544~ (2018)
- P. Gagnon, "Thermo-compression bonding and mass reflow assembly process of 3D logic die stacks", Proc. 67th Electronic Components and Techology Conference (ECTC) (2017), IEEE
- S. Yang, "Development of Low-temperature, Presssureless Copper-to-Copper Bonding by Microfluidic Electroless Interconnection Process", Proc. 68th Electronic Components and Technology Conference (ECTC) (2018), IEEE
- J. Fan, "Effects of surface treatment on the bonding quality of wafer-level Cu-to-Cu thermo-compression bonding for 3D integration", Journal of Micromechanics and Microengineering, 23(4), pp.045025~ (2013)
- E. J. Jang, "Measurement and Improvement of Quantitative Interfacial Adhesion Energy of Cu-Cu Bonding of 3-D Integration", Proc. Journal of the Korean society of machine tool engineers (2009)
- L. Peng, "High-density 3-D interconnect of Cu-Cu contacts with enhanced contact resistance by self-assembled monolayer (SAM) passivation", IEEE Transactions on Electron Devices, 58(8), pp.2500~ (2011)
- E. J. Jang, "Effect of Wet Pretreatment on Interfacial Adhesion Energy of Cu-Cu Thermocompression Bond for 3D IC Packages", Journal of Electronic Materials, 38(12), pp.2449~ (2009)
- W. Yang, "Study of Cu Film Surface Treatment Using Formic Acid Vapor", Solution for Low Temperature Bonding, 2018, pp.165(4), 3080~
- M. S. Park, "Argon Plasma Treatment on Cu surface for Cu bonding in 3D integration and Their Characteristics", Applied Surface Science, 324(1), pp.168~ (2015)
- I. Platzman, "Oxidation of Polycrystalline Copper Thin Films at Ambient Conditions", The Journal of Physical Chemistry C, 112(4), pp.1101~ (2008)
- A. Miura, "Synthesis of Cu3N from CuO and NaNH2", Journal of Asian Ceramic Societies, 2(4), pp.326~ (2014)
- G. Soto, "Copper nitride films produced by reactive pulsed laser deposition", Materials Letters, 57(26-27), pp.4130~ (2003)
- C. Navío, "Intrinsic surface band bending in Cu3N(100) ultrathin films", The American Physical Society, 76(8), pp.085105~ (2007)
- M. C. Biesinger, "Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn", Applied Surface Science, 257(3), pp.887~ (2010)
- X. Y. Fan, "Study on the structure, morphology and properties of Fe-doped Cu3N films", Journal of Physics D: Applied Physics, 47(18), pp.185304~ (2014)