Cargando…

The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model

Thin metal films deposited on polymer substrates are used in flexible electronic devices such as flexible displays or printed memories. They are often fabricated as complicated multilayer structures. Understanding the mechanical behavior of the interface between the metal film and the substrate as w...

Descripción completa

Detalles Bibliográficos
Autores principales: Marx, Vera M., Toth, Florian, Wiesinger, Andreas, Berger, Julia, Kirchlechner, Christoph, Cordill, Megan J., Fischer, Franz D., Rammerstorfer, Franz G., Dehm, Gerhard
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394140/
https://www.ncbi.nlm.nih.gov/pubmed/25937805
http://dx.doi.org/10.1016/j.actamat.2015.01.047
_version_ 1782366257331306496
author Marx, Vera M.
Toth, Florian
Wiesinger, Andreas
Berger, Julia
Kirchlechner, Christoph
Cordill, Megan J.
Fischer, Franz D.
Rammerstorfer, Franz G.
Dehm, Gerhard
author_facet Marx, Vera M.
Toth, Florian
Wiesinger, Andreas
Berger, Julia
Kirchlechner, Christoph
Cordill, Megan J.
Fischer, Franz D.
Rammerstorfer, Franz G.
Dehm, Gerhard
author_sort Marx, Vera M.
collection PubMed
description Thin metal films deposited on polymer substrates are used in flexible electronic devices such as flexible displays or printed memories. They are often fabricated as complicated multilayer structures. Understanding the mechanical behavior of the interface between the metal film and the substrate as well as the process of crack formation under global tension is important for producing reliable devices. In the present work, the deformation behavior of copper films (50–200 nm thick), bonded to polyimide directly or via a 10 nm chromium interlayer, is investigated by experimental analysis and computational simulations. The influence of the various copper film thicknesses and the usage of a brittle interlayer on the crack density as well as on the stress magnitude in the copper after saturation of the cracking process are studied with in situ tensile tests in a synchrotron and under an atomic force microscope. From the computational point of view, the evolution of the crack pattern is modeled as a stochastic process via finite element based cohesive zone simulations. Both, experiments and simulations show that the chromium interlayer dominates the deformation behavior. The interlayer forms cracks that induce a stress concentration in the overlying copper film. This behavior is more pronounced in the 50 nm than in the 200 nm copper films.
format Online
Article
Text
id pubmed-4394140
institution National Center for Biotechnology Information
language English
publishDate 2015
publisher Elsevier Science
record_format MEDLINE/PubMed
spelling pubmed-43941402015-05-01 The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model Marx, Vera M. Toth, Florian Wiesinger, Andreas Berger, Julia Kirchlechner, Christoph Cordill, Megan J. Fischer, Franz D. Rammerstorfer, Franz G. Dehm, Gerhard Acta Mater Article Thin metal films deposited on polymer substrates are used in flexible electronic devices such as flexible displays or printed memories. They are often fabricated as complicated multilayer structures. Understanding the mechanical behavior of the interface between the metal film and the substrate as well as the process of crack formation under global tension is important for producing reliable devices. In the present work, the deformation behavior of copper films (50–200 nm thick), bonded to polyimide directly or via a 10 nm chromium interlayer, is investigated by experimental analysis and computational simulations. The influence of the various copper film thicknesses and the usage of a brittle interlayer on the crack density as well as on the stress magnitude in the copper after saturation of the cracking process are studied with in situ tensile tests in a synchrotron and under an atomic force microscope. From the computational point of view, the evolution of the crack pattern is modeled as a stochastic process via finite element based cohesive zone simulations. Both, experiments and simulations show that the chromium interlayer dominates the deformation behavior. The interlayer forms cracks that induce a stress concentration in the overlying copper film. This behavior is more pronounced in the 50 nm than in the 200 nm copper films. Elsevier Science 2015-05-01 /pmc/articles/PMC4394140/ /pubmed/25937805 http://dx.doi.org/10.1016/j.actamat.2015.01.047 Text en © 2015 Acta Materialia Inc. Elsevier Ltd. All rights reserved. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Marx, Vera M.
Toth, Florian
Wiesinger, Andreas
Berger, Julia
Kirchlechner, Christoph
Cordill, Megan J.
Fischer, Franz D.
Rammerstorfer, Franz G.
Dehm, Gerhard
The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title_full The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title_fullStr The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title_full_unstemmed The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title_short The influence of a brittle Cr interlayer on the deformation behavior of thin Cu films on flexible substrates: Experiment and model
title_sort influence of a brittle cr interlayer on the deformation behavior of thin cu films on flexible substrates: experiment and model
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394140/
https://www.ncbi.nlm.nih.gov/pubmed/25937805
http://dx.doi.org/10.1016/j.actamat.2015.01.047
work_keys_str_mv AT marxveram theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT tothflorian theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT wiesingerandreas theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT bergerjulia theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT kirchlechnerchristoph theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT cordillmeganj theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT fischerfranzd theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT rammerstorferfranzg theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT dehmgerhard theinfluenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT marxveram influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT tothflorian influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT wiesingerandreas influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT bergerjulia influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT kirchlechnerchristoph influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT cordillmeganj influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT fischerfranzd influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT rammerstorferfranzg influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel
AT dehmgerhard influenceofabrittlecrinterlayeronthedeformationbehaviorofthincufilmsonflexiblesubstratesexperimentandmodel