Improvement of the reliability of thin-film interconnections based on the control of the crystallinity of the thin films

Osamu Asai, Ryosuke Furuya, Chuanhong Fan, Ken Suzuki, Hideo Miura

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

6 Citations (Scopus)

Abstract

Electroplated copper thin films have started to be applied to not only interconnections in printed wiring boards, but also thin film interconnections and TSV (Through Silicon Via) in semiconductor devices because of its low electric resistivity and high thermal conductivity. Thus, the electrical reliability of the electroplated copper interconnections was discussed experimentally. The relationship between the electrical properties and crystallographic quality (crystallinity) of electroplated copper thin-film interconnections was investigated. The crystallinity of the grains and grain boundaries of the interconnections was evaluated on the basis of the image quality (IQ) value obtained by electron back-scatter diffraction (EBSD) analysis. The electrical properties of the interconnections vary significantly depending on their crystallinity. The crystallinity also changed drastically as functions of electroplating conditions and the annealing temperature after electroplating. Although the electro migration (EM) resistance of the annealed interconnection is improved, the stress-induced migration (SM) is activated by a high residual tensile stress after annealing caused by the strong constraint of the shrinkage of the film during recrystallization. To improve its electrical reliability without heat treatment after the electroplating, the effects of the seed layer under the interconnections on the crystallinity of the electroplated film was investigated. As a result, the crystallinity was improved by changing the seed layer from Cu to Ru. In addition, the decrease in current density during electroplating also improves the crystallinity. Therefore, both introducing the Ru seed layer in addition to decreasing the current density during electroplating is effective for developing highly reliable copper interconnections.

Original languageEnglish
Title of host publicationASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013
DOIs
Publication statusPublished - 2013 Dec 1
EventASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013 - Burlingame, CA, United States
Duration: 2013 Jul 162013 Jul 18

Publication series

NameASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013
Volume1

Other

OtherASME 2013 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2013
CountryUnited States
CityBurlingame, CA
Period13/7/1613/7/18

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Computer Networks and Communications
  • Computer Science Applications
  • Hardware and Architecture
  • Information Systems
  • Electronic, Optical and Magnetic Materials

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