Effect of substrate bias voltage on the thermal stability of Cu/Ta/Si structures deposited by ion beam deposition

Jae Won Lim, Kouji Mimura, Kiyoshi Miyake, Mutsuo Yamashita, Minoru Isshiki

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The interfacial reactions of the Cu (100nm)/Ta (50nm)/Si structures and their relationship with the microstructure of Ta diffusion barrier are investigated. Ta films were deposited on Si (100) substrates using a non-mass separated ion beam deposition system at various bias voltages ranging from 0 to - 200V. An optimum applied substrate bias voltage of - 125V was found to yield a dominant α-Ta film with a noncolumnar structure, low electrical resistivity (about 40 μΩcm) and smooth surface. A Ta diffusion barrier which was deposited at the optimum bias voltage prevented Cu-Si interaction up to 600°C for 60 min in flowing purified H2, whereas a Ta layer with a columnar structure, deposited at zero bias voltage, degraded at 300°C. Two different reactions of the Cu/Ta (0 V)/Si and the Cu/Ta (-125 V)/Si structures concerning the thermal stability were investigated and discussed on the basis of the experimental results.

Original languageEnglish
Pages (from-to)2780-2785
Number of pages6
JournalJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers
Volume42
Issue number5 A
DOIs
Publication statusPublished - 2003 May

Keywords

  • Bias voltage
  • Diffusion barrier
  • Ion bombardment
  • Resistivity
  • Tantalum

ASJC Scopus subject areas

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

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