Self-forming AlOx layer as Cu diffusion barrier on porous low-k film

Dung Ching Perng, Jia Bin Yeh, Kuo Chung Hsu, Shuo Wen Tsai

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19 Citations (Scopus)

Abstract

The copper diffusion barrier properties of an ultrathin self-forming AlOx layer on a porous low-k film have been investigated. Cu-3 at.% Al alloy films were directly deposited onto porous low-k films by co-sputtering, followed by annealing at various temperatures. Transmission electron microscopy micrographs showed that a ∼ 5 nm layer self-formed at the interface after annealing. X-ray photoelectron spectroscopy analysis showed that this self-formed layer was Al2O3. Sharp declines of the Cu and Si concentrations at the interface indicated a lack of interdiffusion between Cu and the porous low-k film for annealing up to 600 °C for 30 min. The leakage currents from Cu(Al)/porous low-k/Si structures were similar to as-deposited films even after a 700 °C, 5 min anneal while a Cu sample without Al doping failed at lower temperatures. Adding small amounts of Al to bulk Cu is an effective way to self-form copper diffusion layer for advanced copper interconnects.

Original languageEnglish
Pages (from-to)1648-1652
Number of pages5
JournalThin Solid Films
Volume518
Issue number6
DOIs
Publication statusPublished - 2010 Jan 1

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

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