Energy distribution and yield measurement of secondary electrons to evaluate the equilibrium charging voltage of an isolated electrode during negative-ion implantation

Yoshitaka Toyota, Hiroshi Tsuji, Yasuhito Gotoh, Junzo Ishikawa

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9 Citations (Scopus)


The negative-ion implantation method has the advantage that the charging voltage of an isolated electrode, or electrically insulated conductive material, stays as low as at most +10 V during implantation without any charge neutralization. The significant parameters, the energy distribution and the yield of secondary electrons in negative-ion implantation, have been measured in the energy range below 40 keV. The results show that the energy distribution, which is independent of ion energy in shape, has a low energy peak together with a long tail extending toward the high-energy region, and that the yield increases with ion energy. Furthermore, the equilibrium charging-voltage equation of an isolated electrode during negative-ion implantation is presented. The charging voltages estimated according to the equation are found to be in good agreement with those measured directly with a high-input-impedance voltmeter. It is also demonstrated that the charging voltage is proportional to the yield and to ion velocity in the linear region of the kinetic electron emission.

Original languageEnglish
Pages (from-to)6487-6491
Number of pages5
JournalJapanese Journal of Applied Physics
Issue number12
Publication statusPublished - Dec 1995
Externally publishedYes



  • Charging
  • Energy distribution
  • Equilibrium charging-voltage equation
  • Isolated electrode
  • Negative-ion implantation
  • Secondary electron
  • Yield

ASJC Scopus subject areas

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

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