Nondestructive and Nonpreparative Chemical Nanometrology of Internal Material Interfaces at Tunable High Information Depths

Abstract

Improvement in the performance of functional nanoscaled devices involves novel materials, more complex structures, and advanced technological processes. The transitions to heavier elements and to thicker layers restrict access to the chemical and physical characterization of the internal material interfaces. Conventional nondestructive characterization techniques such as X-ray photoelectron spectroscopy suffer from sensitivity and quantification restrictions whereas destructive techniques such as ion mass spectrometry may modify the chemical properties of internal interfaces. Thus, novel methods providing sufficient sensitivity, reliable quantification, and high information depths to reveal interfacial parameters are needed for R&D challenges on the nanoscale. Measurement strategies adapted to nanoscaled samples enable the combination of Near-Edge X-ray Absorption Fine Structure and Grazing Incidence X-ray Fluorescence to allow for chemical nanometrology of internal material interfaces. Their validation has been performed at nanolayered model structures consisting of a silicon substrate, a physically vapor deposited Ni metal layer, and, on top, a chemically vapor deposited B(x)C(y)N(z) light element layer.

Chemical speciation at buried interfaces in high-temperature processed polycrystalline silicon thin-film solar cells on ZnO:Al

“…The detailed procedure for interface speciation is discussed elsewhere. 27 Hence, the binding state of Zn and Al can be concluded depending on the depth. The angle-dependent measurements can be qualitatively interpreted as depth-profiles.…”

Chemical and physical properties in layers and interfaces of nanolayered Si(100)/Ni/BCxNy stacks

“…Therefore, this effect may originate from the presence of a Ni–C bond in the interface between the BCN and the Ni layer. This assumption is confirmed by the results of grazing incidence X‐ray scattering (GIXRS)‐near edge X‐ray absorption fine structure (NEXAFS) measurements …”

“…In the spectra for sample 274 (500 °C), the feature for metallic Ni disappears almost completely, whereas the signal for Ni–O remains nearly constant. XPS signals for Ni–C and Ni–Si, both identified by NEXAFS, are not observed as possibly; they are hidden by the more intensive spectral distribution. A Ni–Si signal (at about 853.0–853.5 eV), if present, is superimposed by the feature for Ni met .…”

“…A Ni–Si signal (at about 853.0–853.5 eV), if present, is superimposed by the feature for Ni met . The low‐energy shoulder of the Ni–O signal observed at low temperatures, which disappears at higher temperatures, could be attributed to a Ni–C bond …”

Interaction of nanoparticle properties and X-ray analytical techniques

“…In this work, both aspects have been combined. In the first step, complementary information about very monodispersed Pt-Ti coreshell nanoparticles with respect to their mass deposition (being the mass per unit area of a specific element of the NPs), surface coverage and chemical binding state using SI-traceable X-ray spectrometry (XRS) [22,23,24,25] methods are provided. The main part of the characterization is to determine the mass deposition and surface coverage using reference-free XRF.…”