Nickel electroless deposition process on chemically pretreated Si(100) wafers in aqueous alkaline solution

Daisuke Niwa, Nao Takano, Taro Yamada, Tetsuya Osaka

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33 Citations (Scopus)

Abstract

Pretreating Si wafer surfaces with hydrochloric acid and hydrogen peroxide mixture (HPM) or ethanol was found to enhance the reactivity of chemical Ni deposition on Si(100) wafers in a simple bath of NiSO4-(NH4)2SO4 at pH 9.0. This phenomenon was identified as the acceleration of anodic reaction involved in chemical Ni deposition reaction on Si wafer surfaces, namely oxidation process of surface Si. Just after immersing into the alkaline bath, a reactive surface where oxidation reaction of Si was accelerated was formed on Si wafer surface with HPM or ethanol pretreatment. On the reactive surface, uniform and glossy Ni deposition film was obtained. In order to clarify the effects of HPM- or ethanol-pretreatment on anodic reaction, the pretreated Si(100) wafers were immersed into aqueous alkaline solution excluding NiSO4, resulting acceleration of Si oxidation compared to the unpretreated Si(100) surface. The progress of surface reactivity was also clarified by open circuit potentials (OCP), XPS, and ex-situ ATR FTIR. Moreover, by using this pretreatment, selective deposition onto nano-patterned Si substrate was performed. A two-dimensional array of fine Ni dots (diameter ca. 80 nm) was successfully fabricated.

Original languageEnglish
Pages (from-to)1295-1300
Number of pages6
JournalElectrochimica Acta
Volume48
Issue number9 SPEC.
DOIs
Publication statusPublished - 2003 Apr 20

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Keywords

  • Chemical pretreatment
  • Electroless deposition
  • Metallic nano-dot arrays
  • Silicon

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Analytical Chemistry
  • Electrochemistry

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