Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1657363 | Surface and Coatings Technology | 2014 | 6 Pages |
Abstract
Electrolytic Cu deposits in a through hole (TH) structure are a critical reliability issue for the high density interconnection (HDI) technologies of three-dimensional packaging. In this study, we investigated the butterfly deposition of electrolytic Cu fillings via optical microscopy (OM) and field-emission scanning electron microscopy (FE-SEM) in combination with electron backscatter diffraction (EBSD). The Cu TH filling proceeds through three distinct regimes relative to the plating time (t): (1) the conformal deposition regime (t = 30-40 min), (2) fast deposition regime (t = 40-55 min), and (3) final deposition regime (t = 55-110 min). The EBSD analyses showed that the Cu grains were predominantly oriented with [111]âTD (TD: transverse direction) in the conformal and fast deposition regimes; however, the [111]âRD (RD: rolling direction) orientation became dominant in the final deposition regime. Additionally, a large number of high angle grain boundaries (HAGBs) with strong coincidence site lattices (CSLs) existed at Σ3 (60° rotation at ã111ã) and Σ9 (38.9° rotation at ã101ã) in the Cu fillings. The microstructural/crystallographic evolutions of the butterfly and other deposition modes (i.e., dogbonding) were compared.
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Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
C.E. Ho, W.Z. Hsieh, C.C. Chen, M.K. Lu,