Investigative characterization of delamination at TiW-Cu interface in low-temperature bonded interconnects

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Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2024-03
Major/Subject
Mcode
Degree programme
Language
en
Pages
Series
Materials Characterization, Volume 209
Abstract
The trend for heterogeneous integration has driven the need for a low-temperature bonding process. Cu-Sn-In based solid-liquid interdiffusion (SLID) bonding technology has been presented as a viable option. However, previous studies have also reported that issues might exist in the interconnect interface towards the substrate, leading to the formation of intermetallic layers at undesired locations. This study carried out a series of characterization methods to determine the root cause of this issue. Cross-sectional observations showed that the problem occurs particularly at the TiW-Cu interface. Examination of the adhesion layer showed possible impurities existing in the layers, compromising its adhesion to copper. Residual stress analyses displayed opposing loading conditions at the interface. The interplay of the two factors resulted in the delamination of the TiW-Cu interface, leading to a pathway for Sn–In atoms. Furthermore, several methods are proposed to mitigate this issue.
Description
Publisher Copyright: © 2024 The Authors
Keywords
Delamination, Interconnect, Interface, SLID
Other note
Citation
Golim, O, Vuorinen, V, Ross, G, Suihkonen, S & Paulasto-Kröckel, M 2024, ' Investigative characterization of delamination at TiW-Cu interface in low-temperature bonded interconnects ', Materials Characterization, vol. 209, 113772 . https://doi.org/10.1016/j.matchar.2024.113772