Scanning tunneling microscopy and spectroscopy of wet-chemically prepared chlorinated Si(111) surfaces

Feigen Cao, Hongbin Yu, James R. Heath

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11 Scopus citations

Abstract

Chlorine-terminated Si(111) surfaces prepared through the wet-chemical treatment of H-terminated Si(111) surfaces with PCl5 (in chlorobenzene) were investigated using ultrahigh vacuum scanning tunneling microscopy (UHV cryo-STM) and tunneling spectroscopy. STM images, collected at 77 K, revealed an unreconstructed 1 × 1 structure for the chlorination layer, consistent with what has been observed for the gas phase chlorination of H-terminated Si(111). However, the wet-chemical chlorination is shown to generate etch pits in the Si-(111) surface, with an increase in etch pit density correlating with increasing PCl5 exposure temperatures. These etch pits were assumed to stabilize the edge structure through the partial removal of the 〈112̄〉 step edges. Tunneling spectroscopy revealed a nonzero density of states at zero bias. This is in contrast to the cases of H-, methyl-, or ethyl-terminated Si(111), in which similar measurements have revealed the presence of a large conductance gap.

Original languageEnglish (US)
Pages (from-to)23615-23618
Number of pages4
JournalJournal of Physical Chemistry B
Volume110
Issue number47
DOIs
StatePublished - Nov 30 2006

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films
  • Materials Chemistry

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