Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses

In this study, the roughness effects of an Ajinomoto build-up film (ABF) on the crystallographic microstructure and corrosion characteristics of electroplated Cu were systematically investigated via scanning electron microscopy (SEM) in conjunction with electron backscatter diffraction (EBSD), trans...

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Main Authors: Pei-Chia Hsu, Zhao-Yu Yang, Chi Lee, Cheng-En Ho, Chih-Ming Chen, Yu-An Shen
Format: Article
Language:English
Published: Elsevier 2025-05-01
Series:Journal of Materials Research and Technology
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Online Access:http://www.sciencedirect.com/science/article/pii/S2238785425006106
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author Pei-Chia Hsu
Zhao-Yu Yang
Chi Lee
Cheng-En Ho
Chih-Ming Chen
Yu-An Shen
author_facet Pei-Chia Hsu
Zhao-Yu Yang
Chi Lee
Cheng-En Ho
Chih-Ming Chen
Yu-An Shen
author_sort Pei-Chia Hsu
collection DOAJ
description In this study, the roughness effects of an Ajinomoto build-up film (ABF) on the crystallographic microstructure and corrosion characteristics of electroplated Cu were systematically investigated via scanning electron microscopy (SEM) in conjunction with electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), X-ray diffraction (XRD), and focused ion beam (FIB) methods. The strong dependences of the Cu crystallographic microstructure and pinhole formation on the ABF roughness were revealed in these investigations. We found that smaller Cu grains with fewer twin boundaries (TBs) and more low-angle grain boundaries (LAGBs) were easily created in the Cu deposits over a low-roughness ABF substrate, which is closely related to pinhole formation because of poor corrosion resistance resulting from numerous grain boundaries (fined grains) and inferior grain boundary (GB) characteristics. Here, we proposed a method that enables the generation of larger Cu grains with more TBs through an appropriate annealing treatment combined with adjusting the plating current density, thereby preventing undesired pinhole formation over a low-roughness ABF substrate. These findings advanced our understanding of the effects of substrate roughness on the Cu microstructure and pinhole formation, which is very beneficial for the application of low-profile substrates for 5G/6G high-frequency signal transmission.
format Article
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institution DOAJ
issn 2238-7854
language English
publishDate 2025-05-01
publisher Elsevier
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series Journal of Materials Research and Technology
spelling doaj-art-8819d8f7262345fc8d61a7a91387ec792025-08-20T02:51:53ZengElsevierJournal of Materials Research and Technology2238-78542025-05-013619320210.1016/j.jmrt.2025.03.100Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnessesPei-Chia Hsu0Zhao-Yu Yang1Chi Lee2Cheng-En Ho3Chih-Ming Chen4Yu-An Shen5Department of Chemical Engineering & Materials Science, Yuan Ze University, Chungli Dist., Taoyuan City, 320, Taiwan, ROCDepartment of Chemical Engineering & Materials Science, Yuan Ze University, Chungli Dist., Taoyuan City, 320, Taiwan, ROCDepartment of Chemical Engineering & Materials Science, Yuan Ze University, Chungli Dist., Taoyuan City, 320, Taiwan, ROCDepartment of Chemical Engineering & Materials Science, Yuan Ze University, Chungli Dist., Taoyuan City, 320, Taiwan, ROC; Corresponding author.Department of Chemical Engineering, National Chung Hsing University, South Dist., Taichung City, 402, Taiwan, ROCDepartment of Materials Science & Engineering, Feng Chia University, Xitun Dist., Taichung City, 407, Taiwan, ROCIn this study, the roughness effects of an Ajinomoto build-up film (ABF) on the crystallographic microstructure and corrosion characteristics of electroplated Cu were systematically investigated via scanning electron microscopy (SEM) in conjunction with electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), X-ray diffraction (XRD), and focused ion beam (FIB) methods. The strong dependences of the Cu crystallographic microstructure and pinhole formation on the ABF roughness were revealed in these investigations. We found that smaller Cu grains with fewer twin boundaries (TBs) and more low-angle grain boundaries (LAGBs) were easily created in the Cu deposits over a low-roughness ABF substrate, which is closely related to pinhole formation because of poor corrosion resistance resulting from numerous grain boundaries (fined grains) and inferior grain boundary (GB) characteristics. Here, we proposed a method that enables the generation of larger Cu grains with more TBs through an appropriate annealing treatment combined with adjusting the plating current density, thereby preventing undesired pinhole formation over a low-roughness ABF substrate. These findings advanced our understanding of the effects of substrate roughness on the Cu microstructure and pinhole formation, which is very beneficial for the application of low-profile substrates for 5G/6G high-frequency signal transmission.http://www.sciencedirect.com/science/article/pii/S2238785425006106Electroplated CuPinholeABF roughnessTwin boundariesCu microstructure5G/6G
spellingShingle Pei-Chia Hsu
Zhao-Yu Yang
Chi Lee
Cheng-En Ho
Chih-Ming Chen
Yu-An Shen
Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
Journal of Materials Research and Technology
Electroplated Cu
Pinhole
ABF roughness
Twin boundaries
Cu microstructure
5G/6G
title Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
title_full Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
title_fullStr Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
title_full_unstemmed Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
title_short Pinhole formation and its mitigation for Cu electrodeposition on the Ajinomoto build-up film (ABF) with different surface roughnesses
title_sort pinhole formation and its mitigation for cu electrodeposition on the ajinomoto build up film abf with different surface roughnesses
topic Electroplated Cu
Pinhole
ABF roughness
Twin boundaries
Cu microstructure
5G/6G
url http://www.sciencedirect.com/science/article/pii/S2238785425006106
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