TY - JOUR
T1 - Transmission scanning electron microscopy
T2 - Defect observations and image simulations
AU - Callahan, Patrick G.
AU - Stinville, Jean Charles
AU - Yao, Eric R.
AU - Echlin, McLean P.
AU - Titus, Michael S.
AU - De Graef, Marc
AU - Gianola, Daniel S.
AU - Pollock, Tresa M.
N1 - Funding Information:
The authors gratefully acknowledge the support of ONR Grant N00014-16-1-2982 and GE Global Research and appreciate useful discussions with J. Laflen, A. Loghin and J. Marte. MDG acknowledges financial support from an ONR Vannevar Bush Faculty Fellowship grant # N00014-16-1-2821. The research reported here made use of shared facilities of the UCSB MRSEC (NSF DMR 1720256), a member of the Materials Research Facilities Network ( www.mrfn.org ).
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/3
Y1 - 2018/3
N2 - The new capabilities of a FEG scanning electron microscope (SEM) equipped with a scanning transmission electron microscopy (STEM) detector for defect characterization have been studied in parallel with transmission electron microscopy (TEM) imaging. Stacking faults and dislocations have been characterized in strontium titanate, a polycrystalline nickel-base superalloy and a single crystal cobalt-base material. Imaging modes that are similar to conventional TEM (CTEM) bright field (BF) and dark field (DF) and STEM are explored, and some of the differences due to the different accelerating voltages highlighted. Defect images have been simulated for the transmission scanning electron microscopy (TSEM) configuration using a scattering matrix formulation, and diffraction contrast in the SEM is discussed in comparison to TEM. Interference effects associated with conventional TEM, such as thickness fringes and bending contours are significantly reduced in TSEM by using a convergent probe, similar to a STEM imaging modality, enabling individual defects to be imaged clearly even in high dislocation density regions. Beyond this, TSEM provides significant advantages for high throughput and dynamic in-situ characterization.
AB - The new capabilities of a FEG scanning electron microscope (SEM) equipped with a scanning transmission electron microscopy (STEM) detector for defect characterization have been studied in parallel with transmission electron microscopy (TEM) imaging. Stacking faults and dislocations have been characterized in strontium titanate, a polycrystalline nickel-base superalloy and a single crystal cobalt-base material. Imaging modes that are similar to conventional TEM (CTEM) bright field (BF) and dark field (DF) and STEM are explored, and some of the differences due to the different accelerating voltages highlighted. Defect images have been simulated for the transmission scanning electron microscopy (TSEM) configuration using a scattering matrix formulation, and diffraction contrast in the SEM is discussed in comparison to TEM. Interference effects associated with conventional TEM, such as thickness fringes and bending contours are significantly reduced in TSEM by using a convergent probe, similar to a STEM imaging modality, enabling individual defects to be imaged clearly even in high dislocation density regions. Beyond this, TSEM provides significant advantages for high throughput and dynamic in-situ characterization.
KW - STEM
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U2 - 10.1016/j.ultramic.2017.11.004
DO - 10.1016/j.ultramic.2017.11.004
M3 - Article
C2 - 29268135
AN - SCOPUS:85038214329
SN - 0304-3991
VL - 186
SP - 49
EP - 61
JO - Ultramicroscopy
JF - Ultramicroscopy
ER -