The impact of electric field strength on the accuracy of boron dopant quantification in silicon using atom probe tomography.

This study investigates the impact of the surface electric field on the quantification accuracy of boron (B) implanted silicon (Si) using atom probe tomography (APT). The Si Charge-State Ratio (CSR(Si) = Si/Si) was used as an indirect measure of the average apex electric field during analysis. For a range of electric fields, the accuracy of the total implanted dose and the depth profile shape determined by APT was evaluated against the National Institute of Standards and Technology Standard Reference Material 2137.

Significant Oxygen Underestimation When Quantifying Barium-Doped SrTiO Layers by Atom Probe Tomography.

In this paper, the capability for quantifying the composition of Ba-doped SrTiO layers from an atom probe measurement was explored. Rutherford backscattering spectrometry and time-of-flight/energy elastic recoil detection were used to benchmark the composition where the amount of titanium was intentionally varied between samples. The atom probe results showed a significant divergence from the benchmarked composition.

Field dependent study on the impact of co-evaporated multihits and ion pile-up for the apparent stoichiometric quantification of GaN and AlN.

For atom probe tomography, multihits and any associated ion pile-up are viewed as an "Achilles" heel when trying to establish accurate stoichiometric quantification. A significant reason for multihits and ion pile-up is credited to co-evaporation events. The impact is the underestimation of one or more elements present due to detector inadequacies when the field evaporated ions are spatially and temporally close.

Potential sources of compositional inaccuracy in the atom probe tomography of InGaAs.

With the objective of applying laser-assisted atom probe tomography to compositional analysis within nanoscale InGaAs devices, experimental conditions that may provide an accurate composition estimate were sought by extensively studying an InGaAs blanket film. Overall, the determined arsenic atomic fraction was found to exhibit an electric field dependent deficiency, which was more pronounced at low field conditions. Although the determined group III site-fraction also showed a (weak) field-dependent deficiency at low field conditions, it remained invariant with analysis conditions and in close agreement with the nominal value at higher field.

Atom probe of GaN/AlGaN heterostructures: The role of electric field, sample crystallography and laser excitation on quantification.

Scaling and non-planar architectures are key factors helping to advance the semiconductor field. Accurate 3-dimensional atomic scale information is therefore sought but this presents a significant metrology challenge. Atom probe tomography has emerged as a strong candidate to fulfill this role, but before it can be considered an accurate and precise metrology method, numerous difficulties need to be overcome.

Overcoming low Ge ionization and erosion rate variation for quantitative ultralow energy secondary ion mass spectrometry depth profiles of Si(1-x)Ge(x)/Ge quantum well structures.

We specify the O(2)(+) probe conditions and subsequent data analysis required to obtain high depth resolution secondary ion mass spectrometry profiles from multiple Ge/Si(1-x)Ge(x) quantum well structures (0.6 ≤ x ≤ 1). Using an O(2)(+) beam at normal incidence and with energies >500 eV, we show that the measured Ge signal is not monotonic with concentration, the net result being an unrepresentative and unquantifiable depth profile.