20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates

Modern power devices face harsh conditions in automotive applications due to high current densities during overload pulses, leading to temperature spikes of up to 300°C at ultra-fast heating rates of up to 106 K/s. This study investigated thermal stresses in 20 µm thick Cu films on Si(100) substrate...

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Main Authors: T. Ziegelwanger, M. Reisinger, B. Vedad, K. Hlushko, S. Van Petegem, J. Todt, M. Meindlhumer, J. Keckes
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Materials & Design
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Online Access:http://www.sciencedirect.com/science/article/pii/S026412752500084X
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author T. Ziegelwanger
M. Reisinger
B. Vedad
K. Hlushko
S. Van Petegem
J. Todt
M. Meindlhumer
J. Keckes
author_facet T. Ziegelwanger
M. Reisinger
B. Vedad
K. Hlushko
S. Van Petegem
J. Todt
M. Meindlhumer
J. Keckes
author_sort T. Ziegelwanger
collection DOAJ
description Modern power devices face harsh conditions in automotive applications due to high current densities during overload pulses, leading to temperature spikes of up to 300°C at ultra-fast heating rates of up to 106 K/s. This study investigated thermal stresses in 20 µm thick Cu films on Si(100) substrates over timescales of 3.2 ms. Heating the Cu film for 500°C at the rapid heating rate of 106 K/s induced a compressive stress of up to –276 MPa, which is almost five times higher than the values measured using the wafer curvature method at the heating rate of 10−1 K/s. Repeated heating pulses between 100–400°C, with a pulse length of 200 µs, led to thermomechanical fatigue in the Cu thin films. On the intergranular scale, voids and cracks formed along high-angle grain boundaries. Whereas on the intragranular scale, Cu exhibited ductile dynamic recovery, where accumulated dislocations formed cell structures and low-angle grain boundaries, helping to relieve part of the tensile stress. Overall, this study underscores the importance of characterizing thin film properties at the timescales encountered in practical applications. Understanding the governing deformation mechanism will lead to enhanced material designs for improved device reliability.
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institution Kabale University
issn 0264-1275
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publishDate 2025-03-01
publisher Elsevier
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spelling doaj-art-c9bc78c9e89841b9b090720bcbe3ffb32025-02-05T04:31:05ZengElsevierMaterials & Design0264-12752025-03-0125111366420 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-ratesT. Ziegelwanger0M. Reisinger1B. Vedad2K. Hlushko3S. Van Petegem4J. Todt5M. Meindlhumer6J. Keckes7Department of Materials Science, Montanuniversität Leoben, Franz Josef Straße 18, 8700 Leoben, Austria; Corresponding author.KAI – Kompetenzzentrum Automobil- und Industrieelektronik GmbH, Europastraße 8, 95245 Villach, AustriaKAI – Kompetenzzentrum Automobil- und Industrieelektronik GmbH, Europastraße 8, 95245 Villach, AustriaDepartment of Materials Science, Montanuniversität Leoben, Franz Josef Straße 18, 8700 Leoben, AustriaStructure and Mechanics of Advanced Materials, PSI Center for Photon Science, Paul Scherrer Institute, Forschungsstrasse 111, 5232 Villigen, SwitzerlandDepartment of Materials Science, Montanuniversität Leoben, Franz Josef Straße 18, 8700 Leoben, AustriaDepartment of Materials Science, Montanuniversität Leoben, Franz Josef Straße 18, 8700 Leoben, AustriaDepartment of Materials Science, Montanuniversität Leoben, Franz Josef Straße 18, 8700 Leoben, AustriaModern power devices face harsh conditions in automotive applications due to high current densities during overload pulses, leading to temperature spikes of up to 300°C at ultra-fast heating rates of up to 106 K/s. This study investigated thermal stresses in 20 µm thick Cu films on Si(100) substrates over timescales of 3.2 ms. Heating the Cu film for 500°C at the rapid heating rate of 106 K/s induced a compressive stress of up to –276 MPa, which is almost five times higher than the values measured using the wafer curvature method at the heating rate of 10−1 K/s. Repeated heating pulses between 100–400°C, with a pulse length of 200 µs, led to thermomechanical fatigue in the Cu thin films. On the intergranular scale, voids and cracks formed along high-angle grain boundaries. Whereas on the intragranular scale, Cu exhibited ductile dynamic recovery, where accumulated dislocations formed cell structures and low-angle grain boundaries, helping to relieve part of the tensile stress. Overall, this study underscores the importance of characterizing thin film properties at the timescales encountered in practical applications. Understanding the governing deformation mechanism will lead to enhanced material designs for improved device reliability.http://www.sciencedirect.com/science/article/pii/S026412752500084XSynchrotron X-ray DiffractionThermomechanical FatigueHigh Strain-RateResidual StressesCu Thin FilmMicroelectronics
spellingShingle T. Ziegelwanger
M. Reisinger
B. Vedad
K. Hlushko
S. Van Petegem
J. Todt
M. Meindlhumer
J. Keckes
20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
Materials & Design
Synchrotron X-ray Diffraction
Thermomechanical Fatigue
High Strain-Rate
Residual Stresses
Cu Thin Film
Microelectronics
title 20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
title_full 20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
title_fullStr 20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
title_full_unstemmed 20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
title_short 20 kHz X-ray diffraction on Cu thin films explores thermomechanical fatigue at high strain-rates
title_sort 20 khz x ray diffraction on cu thin films explores thermomechanical fatigue at high strain rates
topic Synchrotron X-ray Diffraction
Thermomechanical Fatigue
High Strain-Rate
Residual Stresses
Cu Thin Film
Microelectronics
url http://www.sciencedirect.com/science/article/pii/S026412752500084X
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