X‐Ray diffraction microstrain characterization is a technique which enables the quantification of threading dislocations by measuring the radial microstrain field surrounding these defects. This work ...demonstrates how to accurately perform these measurements on a broad range of GaN samples. In particular, for GaN grown on Si substrates with large stress gradient through the layer, the measurements need to be performed on the (20–25) reflection to avoid being affected by a macrostrain influence. A comparison of this characterization with cathodoluminescence and X‐ray diffraction lattice misorientations measurements shows differences in the measurement depth, so the results are affected by the various evolutions of dislocations densities through the layers of the different samples. Independently of the measurement depth, the analysis also highlights a dependence of the X‐ray measurements results on the type of sample, in particular the starting substrate. Microstrain measurements appear therefore as being well suited for the comparison of threading dislocations densities between similar GaN layers. It can be used to replace lattice misorientations measurements, or be associated with them to obtain an edge versus screw dislocations ratio.
This work presents an X‐ray diffraction measurement of threading dislocations densities, based on the surrounding microstrain field analysis. It demonstrates how to accurately characterize different gallium nitride samples, including specimens grown on silicon substrates with large stress gradient through the layer. A comparison between microstrain, lattice misorientations, and cathodoluminescence measurements highlights the potential and the issues of this technique.
The cover image is based on the ECASIA Special Issue Paper Accelerating the development of phase‐change random access memory with in‐fab plasma profiling time‐of‐flight mass spectrometry by Emmanuel ...Nolot et al., https://doi.org/10.1002/sia.6823.
The cover image is based on the ECASIA Special Issue Paper Accelerating the development of phase‐change random access memory with in‐fab plasma profiling time‐of‐flight mass spectrometry by Emmanuel ...Nolot et al., https://doi.org/10.1002/sia.6823.
Abstract
The combination of X‐ray reflectivity (XRR) and grazing incidence X‐ray fluorescence (GIXRF) is a surface sensitive analytical method, which can be used for the characterization of thin ...films and multilayered materials. Both of these techniques are implemented on the same experimental setup and make use of similar mechanical processes and the same fundamental physical concept required for a combined data analysis. The combination of these techniques removes ambiguous results for the characterization of nanometer layers, as well as nanometer depth profiles, resulting in more accurate characterization of thickness, roughness, density, and elemental composition. Due to the vast number of fitting parameters, the estimation of the thin film sample structure is a challenging task. In this paper, we propose a recursive method for estimating the uncertainties of data from GIXRF‐XRR analysis, based on a Bootstrap statistical method. This approach relies on re‐sampling a dataset to estimate statistics on a population by applying random weights. We applied this method on an as‐deposited chalcogenide germanium, antimony, and tellurium (GST) thin film with a carbon‐capping layer. We found good agreement between the experimental and the theoretical XRR‐GIXRF values for a sample structure model, of which the parameters were determined within a confidence interval using the bootstrap method. We also propose an approach for calculating the uncertainty on the solid angle of detection based on Monte Carlo simulations.
In this article, we investigate the influence of germanium content in GeSbSeN-based ovonic threshold switching (OTS) selector devices. We performed physico-chemical analyses on five different ...Gex(SbSe)1–xN alloys to understand how the germanium content influences the material structure and its integrity once submitted to temperatures up to 400 °C. Thanks to the electrical characterization of Gex(SbSe)1–xN OTS devices, we analyze the evolution of the electrical parameters along cycling up to 108 cycles and before and after annealing at 400 °C. Cycle -to -cycle variability and drift phenomenon are also investigated. Finally, we demonstrate how Ge content should be properly tuned to improve the thermal stability of the alloy without affecting the leakage current and the electrical parameters’ variability.
In this article, we investigate the influence of germanium content in GeSbSeN-based ovonic threshold switching (OTS) selector devices. We performed physicochemical analyses on five different ...Ge<inline-formula> <tex-math notation="LaTeX">_{\textsf{\textit{x}}}</tex-math> </inline-formula>(SbSe)<inline-formula> <tex-math notation="LaTeX">_{1-{\textsf{\textit{x}}}</tex-math> </inline-formula>N alloys to understand how the germanium content influences the material structure and its integrity once submitted to temperatures up to 400. Thanks to the electrical characterization of Ge<inline-formula> <tex-math notation="LaTeX">_{\textsf{\textit{x}}}</tex-math> </inline-formula>(SbSe)<inline-formula> <tex-math notation="LaTeX">_{1-{\textsf{\textit{x}}}</tex-math> </inline-formula>N OTS devices, we analyze the evolution of the electrical parameters along cycling up to cycles and before and after annealing at 400. Cycletocycle variability and drift phenomenon are also investigated. Finally, we demonstrate how Ge content should be properly tuned to improve the thermal stability of the alloy without affecting the leakage current and the electrical parameters' variability.
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