High-Voltage Scanning Transmission Electron Microscopy: A Tool for Structural Characterization of Micrometer-Thick Specimens

Abstract

Herein, the advantages of high-voltage scanning transmission electron microscopy (STEM) as a tool for structural characterization of micrometer-thick specimens are reported. Dislocations introduced in a wedge-shaped Si crystal were clearly observed by bright-field STEM operating at 1 MV. Many of the dislocations were straight and parallel to the ©110ª, ©112ª or ©113ª directions. The widths of the dislocations in the STEM images were almost constant at 1316 nm (i.e., 45 pixels) in the thickness range between 1 and 7.5 µm. The latest high-voltage STEM instrumentation is thus useful for imaging crystal defects in micrometer-thick materials, and enables multi-scale fields of view from a few nanometers squared to over 100 µm 2 . [

Athermal Crystal Defect Dynamics in Si Revealed by Cryo-High-Voltage Electron Microscopy

“…Regarding lattice defects characterization of a thick specimen, the authors recently demonstrated that bright-field scanning transmission electron microscopy (BF-STEM) mode in the HVEM shows extreme penetration power . In fact, it has been demonstrated that dislocations in Si can be observed even at a thickness of 14 μm using the 1 MV-STEM. , In this study, we focused on HREM imaging using the cryo-HVEM, while in the future, STEM in cryo-HVEM has potential to reveal crystal defects in a thicker specimen that can be regarded as a bulk.…”

“…6 In fact, it has been demonstrated that dislocations in Si can be observed even at a thickness of 14 μm using the 1 MV-STEM. 28,29 In this study, we focused on HREM imaging using the cryo-HVEM, while in the future, STEM in cryo-HVEM has potential to reveal crystal defects in a thicker specimen that can be regarded as a bulk.…”

Review of “12th Japanese-Polish Joint Seminar on Micro and Nano Analysis (August 29–September 1, 2018)”

“…Figure 1 shows a bright-field STEM image of a wedge-shaped Si specimen with a thickness from 1 µm (leftside) to 9 µm (right-side). 2) The width of the dislocation lines is almost constant at 1316 nm in the region with a thickness of 1 to 7.5 µm, suggesting that a wedge-shaped specimen with a thickness up to 7.5 µm can be observed in focus using STEM operated at an acceleration voltage of 1 MV. This is because STEM is less susceptible to the effect of resolution reduction due to chromatic aberration than TEM.…”

“…Sadamatsu et al 11) examined a single crystalline Si including artificially introduced high-density dislocations using energy-filtered UHVEM in combination with electron energy-loss spectroscopy, and demonstrated that the dislocations are clearly visible even in bulk specimens over 10 µm-thick. On the other hand, Sato et al 2,12) observed the dislocations in thick specimens by STEM using UHVEM installed at the Research Center for Ultra-High Voltage Electron Microscopy, Osaka University. Figure 1 shows a bright-field STEM image of a wedge-shaped Si specimen with a thickness from 1 µm (leftside) to 9 µm (right-side).…”