Scanning electron microscopy (SEM) is currently widely employed in metrology applications, where nanoscale imaging in a liquid environment is in high demand; however, information regarding the nano-objects size measurement limitation of the SEM applications is lacking. In this thesis, we study the size measurement limit of nano gold particle by theoretical equation, Monte-Carlo Simulation and SEM. The size effect of the nanoparticles in the aqueous environment of the membrane based liquid devices measured by SEM was studied. The results of theoretical calculation and simulation show that the analytical capability of SEM decreases with the liquid depth. When the membrane thickness is less than 30 nm, the electron beam penetrates the membrane and reaches the depth of 100 nm below the membrane. The size of the smallest detectable particle is between 10 nm to 20 nm. The experimental results show that the measuring limit of nano gold particle size with 30 nm Si 3 N 4 membrane and 15 keV electron energy is 20 nm. The measuring of polystyrene particle size is not easy to image. We inferred that the reason should be related to the atomic weight and conductivity of the particles. The particle size measured by SEM has a certain error, so it is necessary to take an average after multiple measurements to increase the reliability of the particle size measurement result.
Main text The CCM.FF-K6.2017 comparison was organised for the purpose of determination of the degree of equivalence of the national standards for low-pressure gas flow measurement over the range 2 mL/min to 10 L/min. Four molbloc-L flow elements and a molbox1+ were used as the transfer standards. Ten laboratories from three RMOs participated between August 2017 and January 2020 - EURAMET: INRIM (Italy); LNE (France); PTB (Germany); METAS (Switzerland); CMI (Czech Republic); SIM: NIST (USA); APMP: NMIJ/AIST (Japan); KRISS (Korea); NMIA (Australia); CMS (Chinese Taipei). The measurements were provided at prescribed reference pressure and temperature conditions. All results were used in the determination of the key comparison reference value (KCRV) and the uncertainty of the KCRV. The reference value was determined at each flow separately following the procedure presented by M G Cox [1]. The degree of equivalence with the KCRV was calculated for each flow and laboratory. This KCRV can now be used in further regional comparisons. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Wafer fabrication is a critical part of the semiconductor process when the finest linewidth with the improvement of technology continues to decline. The nanoparticles contained in the slurry or ultrapure water used for cleaning have a large influence on the manufacturing process. Therefore, semiconductor industry is hoping to find a viable method for on-line detection of the nanoparticles size and concentration. Resistive pulse sensing technology is one of the methods that may cover this question. There were a lot of reports showing that nanoparticles properties of materials differ significantly from their properties at nano length scales. So, we want to clear the translocation dynamic and ion current changes in measurement of metal nanoparticles or non-metal nanoparticles in different concentration electrolytes through the nanopore when resistive pulse sensing technology has been used. In this study, we try to use a finite element method that contains three governing equations to do multiphysics coupling simulations. The Navier-Stokes equation describes the laminar motion, the Nernst-Planck equation describes the ion transport, and the Poisson equation describes the potential distribution in the flow channel. Then, the reliability of the simulation results was verified by resistive pulse sensing test. The existing results showed that the lower the ion concentration the greater the effect of resistive pulse sensing was. We investigated the effect of resistive pulse sensing on different materials by both simulations and experiments. The results are discussed in this article.
Scanning electron microscopy (SEM) and transmission electron microscopy (TEM), when applied in combination with a silicon chip, can be used to study the physical and chemical properties of nanoparticles in the liquid phase. However, these measurement approaches lack repeatability, accuracy, and reproducibility with regard to nanoparticle size and distribution estimates. We applied bootstrapping and the probability density function for our measurement estimates. Our results revealed that TEM outperformed SEM in terms of particle size and size distribution measurement. The effects of electron probe energy and position on the nanoparticle measurement results are outlined herein.
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