Robust ultra-thin RuMo alloy film as a seedless Cu diffusion barrier

Kuo Chung Hsu, Dung Ching Perng, Yi Chun Wang

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

This study investigated the properties of 5 nm-thick RuMo film as a Cu diffusion barrier. The sheet resistance variation and X-ray diffraction patterns show that the RuMo alloy film has excellent barrier performance and that it is stable upon annealing at 725 °C against Cu. The transmission electron microscopy micrograph and diffraction patterns show that the RuMo film is an amorphous-like structure, whereas pure Ru film is a nano-crystalline structure. The elements' depth profiles, analyzed by X-ray photoelectron spectroscopy, indicate no inter-diffusion behavior between the Cu and Si layer, even annealing at 700 °C. Lower leakage current has been achieved from the Cu/barrier/insulator/Si test structure using RuMo film as the barrier layer. A 5 nm ultrathin RuMo film provided two orders of magnitude improvement in leakage current and also exhibited a 175 °C improvement in thermal stability than that of the pure Ru film. It is a potential candidate as a seedless Cu diffusion barrier for advanced Cu interconnects.

Original languageEnglish
Pages (from-to)102-106
Number of pages5
JournalJournal of Alloys and Compounds
Volume516
DOIs
Publication statusPublished - 2012 Mar 5

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All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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