Mass transport mechanism of Cu species at the metal/dielectric interfaces with a graphene barrier

Yuda Zhao, Zhaojun Liu, Tieyu Sun, Ling Zhang, Wenjing Jie, Xinsheng Wang, Yizhu Xie, Yuen Hong Tsang, Hui Long, Yang Chai

Research output: Journal article publicationJournal articleAcademic researchpeer-review

42 Citations (Scopus)

Abstract

The interface between the metal and dielectric is an indispensable part in various electronic devices. The migration of metallic species into the dielectric can adversely affect the reliability of the insulating dielectric and can also form a functional solid-state electrolyte device. In this work, we insert graphene between Cu and SiO2as a barrier layer and investigate the mass transport mechanism of Cu species through the graphene barrier using density functional theory calculations, second-ion mass spectroscopy (SIMS), capacitance-voltage measurement, and cyclic voltammetry. Our theoretical calculations suggest that the major migration path for Cu species to penetrate through the multiple-layered graphene is the overlapped defects larger than 0.25 nm2. The depth-profile SIMS characterizations indicate that the "critical" thickness of the graphene barrier for completely blocking the Cu migration is 5 times smaller than that of the conventional TaN barrier. Capacitance-voltage and cyclic voltammetry measurement reveal that the electrochemical reactions at the Cu/SiO2interface become a rate-limiting factor during the bias-temperature stressing process with the use of a graphene barrier. These studies provide a distinct roadmap for designing controllable mass transport in solid-state electrolyte devices with the use of a graphene barrier.
Original languageEnglish
Pages (from-to)12601-12611
Number of pages11
JournalACS Nano
Volume8
Issue number12
DOIs
Publication statusPublished - 1 Jan 2014

Keywords

  • barrier
  • Cu interconnect
  • graphene
  • mass transport

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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