Atom counting at surfaces

David L. Pappas, David M. Hrubowchak, Matthew H. Ervin, Nicholas Winograd

Research output: Contribution to journalArticlepeer-review

62 Scopus citations


Multiphoton resonance ionization has been combined with energetic ion bombardment to examine dopant concentrations of indium on the surface of silicon. The results yield a linear relation between the indium concentration and the known bulk values and a detection limit of 9 parts per trillion, at a mass resolution exceeding 160. This measurement, which surpasses the limits of any previous surface analysis by a factor of 100, has been made possible with an experimental configuration that optimizes sampling and detection efficiency while reducing background noise to virtually zero. During the analysis, submonolayer quantities of the surface are removed, so that as few as 180 surface atoms may be counted.

Original languageEnglish (US)
Pages (from-to)64-66
Number of pages3
Issue number4887
StatePublished - 1989

All Science Journal Classification (ASJC) codes

  • General


Dive into the research topics of 'Atom counting at surfaces'. Together they form a unique fingerprint.

Cite this