Improvement of the long-term reliability of interconnection by controlling the crystallinity of grain boundaries

Takahiro Nakanishi, Ken Suzuki, Hideo Miura

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

4 Citations (Scopus)

Abstract

Electroplated copper thin films have started to be employed as the interconnection material in TSV structures of 3D semiconductor modules because of its low electric resistivity and high thermal conductivity. However, electrical and mechanical properties of electroplated copper thin-films have been found to vary drastically depending on their microtexture. In particular, the crystallographic quality (crystallinity) of grain boundaries in the electroplated copper thin-films plays an important role on the variations of these properties and the long-term reliability of the interconnections. This is because grain boundaries are the area where the atomic alignment of mateerials is disordered and thus, various defects such as vacancies, dislocations, impurities, and strain easily concentrate around them. This disorder of the atomic alignment causes the increase in the electrical resistivity, diffusion constant along the grain boundaries, and the brittleness of the material. Therefore, it is very important to evaluate the characteristics of a grain boundary quantitatively in order to control and assure the properties of the electroplated copper thin films. In this study, a novel tensile test method that can measure the strength of a grain boundary has been developed by using a focused ion beam system. In order to investigate the effect of the crystallinity of grain boundaries on their strength, an electron back-scatter diffraction method (EBSD) was employed for the quantitative characterization of grain boundaries. It was confirmed that the strength of grain boundaries with low crystallinity was much lower than that with high crystallinity.

Original languageEnglish
Title of host publicationAdvanced Electronics and Photonics, Packaging Materials and Processing; Advanced Electronics and Photonics
Subtitle of host publicationPackaging, Interconnect and Reliability; Fundamentals of Thermal and Fluid Transport in Nano, Micro, and Mini Scales
PublisherAmerican Society of Mechanical Engineers
ISBN (Electronic)9780791856895
DOIs
Publication statusPublished - 2015 Jan 1
EventASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2015, collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels - San Francisco, United States
Duration: 2015 Jul 62015 Jul 9

Publication series

NameASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2015, collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels
Volume2

Other

OtherASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2015, collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels
CountryUnited States
CitySan Francisco
Period15/7/615/7/9

ASJC Scopus subject areas

  • Process Chemistry and Technology

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