Abstract
The pile-up of arsenic at the Si/SiO2 interface after As implantation and annealing was investigated
by high resolution Z-contrast imaging, electron energy-loss spectroscopy EELS, grazing incidence
x-ray fluorescence spectroscopy GI-XRF, secondary ion mass spectrometry, x-ray photoelectron
spectroscopy, Rutherford backscattering spectrometry, as well as Hall mobility and four-point probe
resistivity measurements. After properly taking into account their respective artifacts, the results of
all methods are compatible with each other, with EELS and GI-XRF combined with etching
providing similar spatial resolution on the nanometer scale for the dopant profile. The sheet
concentration of the piled-up As at the interface was found to be 11015 cm−2 for an implanted
dose of 11016 cm−2 with a maximum concentration of 10 at. %. The strain observed in the
Z-contrast images also suggests a significant concentration of local distortions within 3 nm from the
interface, which, however, do not seem to involve intrinsic point defects.