Quantitative analysis of helium by post-ionization method using femtosecond laser technique

Hisayoshi Yurimoto, Ken ichi Bajo, Isao Sakaguchi, Taku T. Suzuki, Amy Jurewicz, Satoru Itose, Kiichiro Uchino, Morio Ishihara

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Helium has the largest ionization potential of all elements; thus, it is difficult to ionize for measurement by mass spectrometry. In order to analyze He, a tunnel-ionization time-of-flight sputtered neutral mass spectrometry system (called LIMAS) has recently been developed. LIMAS uses a femtosecond laser technique and can ionize He. We quantified the effectiveness of this method for He analysis from a 2.5 × 4 µm2 area of He-implanted silicon. The amount of He in an implant was quantified by measuring the ion current, giving a nominal implant fluence per unit area. Thus, the fraction of total He measured by LIMAS during depth profiling could be quantified by comparison with the He concentration of the reference implant. The He+ intensities normalized by host ions of Si linearly correlated with the known He concentrations with a reproducibility of 10% at concentrations less than 1021 cm−3. The detection limit was down to 1018 He cm−3 (20 ppm). For concentrations exceeding 1021 cm−3, the He intensities are smaller than those expected from the lower concentration range. This non-linearity may reflect the limit of retention of He in the Si lattice, because He is chemically inert.

Original languageEnglish (US)
Pages (from-to)1181-1184
Number of pages4
JournalSurface and Interface Analysis
Volume48
Issue number11
DOIs
StatePublished - Nov 1 2016

Fingerprint

Helium
Ultrashort pulses
quantitative analysis
Ionization
Mass spectrometry
helium
Ions
ionization
Depth profiling
Ionization potential
Silicon
Chemical analysis
lasers
Tunnels
mass spectroscopy
ionization potentials
ion currents
tunnels
low concentrations
fluence

Keywords

  • femtosecond laser
  • helium
  • mass spectrometry
  • post-ionization
  • quantitative analysis
  • tunnel-ionization

ASJC Scopus subject areas

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

Cite this

Yurimoto, H., Bajo, K. I., Sakaguchi, I., Suzuki, T. T., Jurewicz, A., Itose, S., ... Ishihara, M. (2016). Quantitative analysis of helium by post-ionization method using femtosecond laser technique. Surface and Interface Analysis, 48(11), 1181-1184. https://doi.org/10.1002/sia.6119

Quantitative analysis of helium by post-ionization method using femtosecond laser technique. / Yurimoto, Hisayoshi; Bajo, Ken ichi; Sakaguchi, Isao; Suzuki, Taku T.; Jurewicz, Amy; Itose, Satoru; Uchino, Kiichiro; Ishihara, Morio.

In: Surface and Interface Analysis, Vol. 48, No. 11, 01.11.2016, p. 1181-1184.

Research output: Contribution to journalArticle

Yurimoto, H, Bajo, KI, Sakaguchi, I, Suzuki, TT, Jurewicz, A, Itose, S, Uchino, K & Ishihara, M 2016, 'Quantitative analysis of helium by post-ionization method using femtosecond laser technique', Surface and Interface Analysis, vol. 48, no. 11, pp. 1181-1184. https://doi.org/10.1002/sia.6119
Yurimoto, Hisayoshi ; Bajo, Ken ichi ; Sakaguchi, Isao ; Suzuki, Taku T. ; Jurewicz, Amy ; Itose, Satoru ; Uchino, Kiichiro ; Ishihara, Morio. / Quantitative analysis of helium by post-ionization method using femtosecond laser technique. In: Surface and Interface Analysis. 2016 ; Vol. 48, No. 11. pp. 1181-1184.
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