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Damascene-Patterned Metal-Adhesive (Cu-BCB) Redistribution Layers

Published online by Cambridge University Press:  26 February 2011

Ronald J. Gutmann ,
J. Jay McMahon  and
Jian-Qiang Lu
Ronald J. Gutmann
Affiliation:
gutmar@rpi.edu, RPI, CIE, 6015 CII, 110 8th st, Troy, NY, 12180, United States
J. Jay McMahon
Affiliation:
mcmahj@rpi.edu, Rensselaer Polytechnic Institute, Center for Integrated Electronics, CII 6015, 110 8th St, Troy, NY, 12180, United States
Jian-Qiang Lu
Affiliation:
luj@rpi.edu, Rensselaer Polytechnic Institute, Center for Integrated Electronics, CII 6015, 110 8th St, Troy, NY, 12180, United States
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Abstract

A monolithic, wafer-level three-dimensional (3D) technology platform is described that is compatible with next-generation wafer level packaging (WLP) processes. The platform combines the advantages of both (1) high bonding strength and adaptability to IC wafer topography variations with spin-on dielectric adhesive bonding and (2) process integration and via-area advantages of metal-metal bonding. A copper-benzocyclobutene (Cu-BCB) process is described that incorporates single-level damascene-patterned Cu vias with partially-cured BCB as the bonding adhesive layer. A demonstration vehicle consisting of a two-wafer stack of 2-4 μm diameter vias has shown the bondability of both Cu-to-Cu and BCB-to-BCB. Planarization conditions to achieve BCB-BCB bonding with low-resistance Cu-Cu contacts have been examined, with wafer-scale planarization requirements compared to other 3D platforms. Concerns about stress induced at the tantalum (Ta) liner-to-BCB interface resulting in partial delamination are discussed. While across-wafer uniformity has not been demonstrated, the viability of this WLP-compatible 3D platform has been shown.

Keywords

adhesivebondingmetal
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 970: Symposium Y – Enabling Technologies for 3-D Integration , 2006 , 0970-Y04-02
Copyright
Copyright © Materials Research Society 2007

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References

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