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Wang F, Sun Y, Cao M, Nishi R. The influence of structure depth on image blurring of micrometres-thick specimens in MeV transmission electron imaging. Micron 2016; 83:54-61. [PMID: 26897587 DOI: 10.1016/j.micron.2016.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 02/05/2016] [Accepted: 02/05/2016] [Indexed: 11/18/2022]
Abstract
This study investigates the influence of structure depth on image blurring of micrometres-thick films by experiment and simulation with a conventional transmission electron microscope (TEM). First, ultra-high-voltage electron microscope (ultra-HVEM) images of nanometer gold particles embedded in thick epoxy-resin films were acquired in the experiment and compared with simulated images. Then, variations of image blurring of gold particles at different depths were evaluated by calculating the particle diameter. The results showed that with a decrease in depth, image blurring increased. This depth-related property was more apparent for thicker specimens. Fortunately, larger particle depth involves less image blurring, even for a 10-μm-thick epoxy-resin film. The quality dependence on depth of a 3D reconstruction of particle structures in thick specimens was revealed by electron tomography. The evolution of image blurring with structure depth is determined mainly by multiple elastic scattering effects. Thick specimens of heavier materials produced more blurring due to a larger lateral spread of electrons after scattering from the structure. Nevertheless, increasing electron energy to 2MeV can reduce blurring and produce an acceptable image quality for thick specimens in the TEM.
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Affiliation(s)
- Fang Wang
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Ying Sun
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
| | - Meng Cao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China.
| | - Ryuji Nishi
- Research Center for Ultrahigh Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Yamasaki J, Mutoh M, Ohta S, Yuasa S, Arai S, Sasaki K, Tanaka N. Analysis of nonlinear intensity attenuation in bright-field TEM images for correct 3D reconstruction of the density in micron-sized materials. Microscopy (Oxf) 2014; 63:345-55. [PMID: 24891385 DOI: 10.1093/jmicro/dfu020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To obtain the correct tomographic reconstruction of micron-sized materials, the nonlinear intensity attenuation of bright-field transmission electron microscopy (BF-TEM) images was analyzed as a function of the sample thickness using a high-voltage electron microscope. The intensity attenuation was precisely measured relative to the projection thickness of carbon microcoils (CMCs) at acceleration voltages of 400-1000 kV using objective apertures (OAs) with radii of 2.1-28 nm(-1). The results show that the nonlinearity is strongly dependent on the OA size and the acceleration voltage. The influence of nonlinearity on tomographic reconstructions was also examined using a specially developed 360°-tilt sample holder. Sliced images of the reconstructed volumes indicated that an increase in the nonlinearity caused artificial fluctuations in the internal density of materials and inaccurate shapes of the objects in more significant cases. Conditions sufficient for reconstruction with the correct density have been estimated to be 0.67 of the minimum electron transmittance, and for reconstructions with correct shapes, 0.4. This information enables foreseeing the quality of the reconstruction from a single BF-TEM image prior to the tilt-series acquisition. As a result to demonstrate the appropriateness of these conditions, a CMC with a diameter of 3.7 µm was reconstructed successfully; i.e. not only the shape but also the internal density were correctly reproduced using electron tomography.
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Affiliation(s)
- Jun Yamasaki
- Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Michihiro Mutoh
- Department of Crystalline Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Shigemasa Ohta
- JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Syuichi Yuasa
- JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Shigeo Arai
- EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Katsuhiro Sasaki
- Department of Quantum Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
| | - Nobuo Tanaka
- EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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Cao M, Wang F, Qiao ZW, Zhang HB, Nishi R. Electron tomographic resolution of microns-thick specimens in the ultrahigh voltage electron microscope. Micron 2013; 49:71-4. [PMID: 23528481 DOI: 10.1016/j.micron.2013.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 11/29/2022]
Abstract
In this study, we determine the electron tomography (ET) resolution for microns-thick specimens by experiment in the ultra-high voltage electron microscope. A tilt series of projection images of a tilted 8μm thick epoxy-resin film are first acquired. Tomographic reconstructions are then calculated and the resolution is evaluated with the Fourier shell correlation method. The ET resolution of 32nm is achieved under the condition of 2MV accelerating voltage. We also demonstrate that some high tilt angle projections may be little useful for improving the final ET resolution because of the corresponding poor image qualities. These results are helpful to understand the possibility and limitation of ET applications in microns-thick specimens.
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Affiliation(s)
- Meng Cao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
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Wang F, Zhang HB, Cao M, Nishi R, Takaoka A. Determination of the linear attenuation range of electron transmission through film specimens. Micron 2010; 41:769-74. [PMID: 20558075 DOI: 10.1016/j.micron.2010.05.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/19/2010] [Accepted: 05/22/2010] [Indexed: 11/26/2022]
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Wang F, Zhang HB, Cao M, Nishi R, Takaoka A. Image quality of microns-thick specimens in the ultra-high voltage electron microscope. Micron 2010; 41:490-7. [DOI: 10.1016/j.micron.2010.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/18/2010] [Accepted: 01/19/2010] [Indexed: 11/25/2022]
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6
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Abstract
We have analysed the formation of streak artefacts in the reconstruction based on the filtered back projection algorithm in electron tomography (ET) and accordingly applied an adaptive interpolation technique to artefact reduction. In the adaptive interpolation to recover the missing information, the edge positions in a projection curve were tracked to reduce the interpolation error. A simulation was used to demonstrate the effectiveness of the artefact reduction. Furthermore, image reconstruction of integrated circuit specimens in the ET experiments with the ultra-high voltage electron microscope show that the strong streak artefacts can be reduced effectively by our artefact reduction technique.
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Affiliation(s)
- M Cao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
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Wang F, Zhang HB, Cao M, Nishi R, Takaoka A. Multiple scattering effects of MeV electrons in very thick amorphous specimens. Ultramicroscopy 2010; 110:259-68. [DOI: 10.1016/j.ultramic.2009.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 12/08/2009] [Accepted: 12/22/2009] [Indexed: 10/20/2022]
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Ercius P, Gignac LM, Hu CK, Muller DA. Three-dimensional measurement of line edge roughness in copper wires using electron tomography. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2009; 15:244-250. [PMID: 19460181 DOI: 10.1017/s143192760909028x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Electrical interconnects in integrated circuits have shrunk to sizes in the range of 20-100 nm. Accurate measurements of the dimensions of these nanowires are essential for identifying the dominant electron scattering mechanisms affecting wire resistivity as they continue to shrink. We report a systematic study of the effect of line edge roughness on the apparent cross-sectional area of 90 nm Cu wires with a TaN/Ta barrier measured by conventional two-dimensional projection imaging and three-dimensional electron tomography. Discrepancies in area measurements due to the overlap of defects along the wire's length lead to a 5% difference in the resistivities predicted by the two methods. Tomography of thick cross sections is shown to give a more accurate representation of the original structure and allows more efficient sampling of the wire's cross-sectional area. The effect of roughness on measurements from projection images is minimized for cross-section thicknesses less than 50 nm, or approximately half the spatial frequency of the roughness variations along the length of the investigated wires.
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Affiliation(s)
- Peter Ercius
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853, USA.
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Friedrich H, de Jongh PE, Verkleij AJ, de Jong KP. Electron Tomography for Heterogeneous Catalysts and Related Nanostructured Materials. Chem Rev 2009; 109:1613-29. [DOI: 10.1021/cr800434t] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Heiner Friedrich
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Molecular Cell Biology, Utrecht University, Padualaan 8, 2584 CH, Utrecht, The Netherlands
| | - Petra E. de Jongh
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Molecular Cell Biology, Utrecht University, Padualaan 8, 2584 CH, Utrecht, The Netherlands
| | - Arie J. Verkleij
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Molecular Cell Biology, Utrecht University, Padualaan 8, 2584 CH, Utrecht, The Netherlands
| | - Krijn P. de Jong
- Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA, Utrecht, The Netherlands, and Molecular Cell Biology, Utrecht University, Padualaan 8, 2584 CH, Utrecht, The Netherlands
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Cao M, Zhang HB, Li C, Nishi R. Effect of sample structure on reconstruction quality in computed tomography. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:026104. [PMID: 19256680 DOI: 10.1063/1.3077940] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have investigated the effect of a sample structure on reconstruction quality in computed tomography (CT). A power spectrum with respect to a projection angle is used to represent the sample structure. The condition for high quality reconstruction is then analyzed with the simulation and the electron tomography experiment based on an ultrahigh voltage electron microscope. The truncated terms in the power spectrum are suggested to be less than 10(-3) for high quality reconstruction. The effect of the sample structure is believed to be an important factor for high quality reconstruction of complex samples in various CT techniques.
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Affiliation(s)
- Meng Cao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Department of Electronic Science and Technology, Xi'an Jiaotong University, Xi'an 710049, People's Republic of China
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