Characteristics of a cluster-ion beam of Os3(CO) n+ (n = 7 or 8) for low-damage sputtering

Yukio Fujiwara, Kouji Kondou, Yoshikazu Teranishi, Hidehiko Nonaka, Toshiyuki Fujimoto, Akira Kurokawa, Shingo Ichimura, Mitsuhiro Tomita

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Abstract

A cluster-ion source has been developed to produce stable ion beams of metal-cluster-complex ions. As a metal cluster complex, triosmium dodecacarbonyl, Os3(CO)12, was used, which has a molecular weight of 906.7. Using the ion source, energy dependence of beam current and sputtering yield of silicon bombarded with Os3(CO)n + (n = 7-8) were investigated at beam energies from 2 to 10 keV under the normal incidence condition. By high-resolution Rutherford backscattering spectrometry (HR-RBS), a silicon target bombarded with the normally incident Os3(CO)7-8+ ions at 10 keV with oxygen flooding at 5 × 10-4 Pa was analyzed. The experimental results showed that the ion-beam current increased almost linearly with the acceleration voltage. It was found that the sputtering yields of silicon with Os 3(CO)7-8+ ions varied substantially with beam energy. The sputtering yield with Os3(CO)7-8+ at 10 keV was higher than that with SF5+ or Ar+ by a factor of 3-20, whereas the yield at 3 keV was lower than that with Ar+. In the case of 2 keV, deposition was found to occur on the silicon surface. The substantial variation in the sputtering yield with beam energy would arise from the lower kinetic energy of each atom constituting the metal-cluster-complex ions. From HR-RBS results, it was confirmed that the constituent atoms of the Os3(CO)7-8+ ions, Os, C, and O, were implanted into the silicon target. The observed depth profiles of Os and C atoms were in good agreement with results of TRIM simulation, while that of the O atom was significantly different from the simulation results. The depth profile of the O atom was examined in terms of oxygen diffusion and implantation.

Original languageEnglish
Pages (from-to)1539-1544
Number of pages6
JournalSurface and Interface Analysis
Volume38
Issue number12-13
DOIs
Publication statusPublished - 2006 Dec 1

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Keywords

  • Deposition
  • Ion beam
  • Metal cluster complex
  • Os(CO)
  • RBS
  • SIMS
  • Sputtering
  • TRIM

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Materials Chemistry

Cite this

Fujiwara, Y., Kondou, K., Teranishi, Y., Nonaka, H., Fujimoto, T., Kurokawa, A., Ichimura, S., & Tomita, M. (2006). Characteristics of a cluster-ion beam of Os3(CO) n+ (n = 7 or 8) for low-damage sputtering. Surface and Interface Analysis, 38(12-13), 1539-1544. https://doi.org/10.1002/sia.2423