TY - JOUR
T1 - Atom counting at surfaces
AU - Pappas, David L.
AU - Hrubowchak, David M.
AU - Ervin, Matthew H.
AU - Winograd, Nicholas
PY - 1989
Y1 - 1989
N2 - 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.
AB - 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.
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U2 - 10.1126/science.243.4887.64
DO - 10.1126/science.243.4887.64
M3 - Article
AN - SCOPUS:0040242489
SN - 0036-8075
VL - 243
SP - 64
EP - 66
JO - Science
JF - Science
IS - 4887
ER -