Electron-induced X-ray emission spectroscopy (EXES) combined with a
semi-empirical electron scattering model, which describes the ionizations inside a
material under electron irradiation, is used to determine the depth profile of
shallow and ultra-shallow dopants in silicon. Two approaches are presented, depending
on whether the shape of the profile is known or not. To test the method, X-ray intensities
of implanted phosphorus atoms at various energies and doses in silicon are
measured at a wide range of incident electron energies. From the experimental data
combined with the model, the resulting profile parameters are determined. Comparison
of secondary ion mass spectrometry and EXES associated with the electron scattering
model shows that the proposed method is suitable for determining the shallow implant profiles
with a depth resolution of one nanometer.