Variation of the strength and fracture mode of a grain and a grain boundary in polycrystalline copper thin films

Guoxiong Zheng, Yifan Luo, Ken Suzuki, Hideo Miura

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In this study, variation of the strength of electroplated copper thin films depending on the crystallinity was quantitatively evaluated by EBSD (electron back scatter diffraction) and a micro tensile test using FIB (focused ion beam) technologies. For the crystallinity evaluation, the order of the atomic arrangement was numerically evaluated by using the IQ (image quality) value obtained from the EBSD method. For the strength evaluation, tensile strength, yield stress and CRSS (critical resolved shear stress) were measured by the micro tensile test on bicrystal specimens fabricated from electroplated copper thin films. From the results of these experiments, both the intergranular fracture and the transgranular fracture were observed in the bicrystal specimens. It was also found that there is a critical IQ value at which the fracture mode of the bicrystal specimen changes from brittle intergranular fracture at the grain boundary to ductile transgranular fracture within the grain. The intergranular strength monotonically decreases with decreasing the IQ value because the total number of atomic bonds decreases in the grain boundary with low IQ value where the lattice mismatch occurs and the atomic density is relatively low, and thus, the bonding strength between grains decreases. On the other hand, as the order of the atomic arrangement increases, dislocation movement occurs easily, so that the transgranular strength monotonically decreases as the IQ value increases. It is clarified that the strength and the fracture modes of a grain boundary and a grain drastically change as a function of crystallinity.

Original languageEnglish
Title of host publication13th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2018
PublisherIEEE Computer Society
Pages119-122
Number of pages4
ISBN (Electronic)9781538656150
DOIs
Publication statusPublished - 2019 Jan 24
Event13th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2018 - Taipei, Taiwan, Province of China
Duration: 2018 Oct 242018 Oct 26

Publication series

NameProceedings of Technical Papers - International Microsystems, Packaging, Assembly, and Circuits Technology Conference, IMPACT
Volume2018-October
ISSN (Print)2150-5934
ISSN (Electronic)2150-5942

Conference

Conference13th International Microsystems, Packaging, Assembly and Circuits Technology Conference, IMPACT 2018
CountryTaiwan, Province of China
CityTaipei
Period18/10/2418/10/26

ASJC Scopus subject areas

  • Hardware and Architecture
  • Control and Systems Engineering
  • Electrical and Electronic Engineering

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