Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1589474 | Micron | 2010 | 8 Pages |
Abstract
Image quality of MeV transmission electrons is an important factor for both observation and electron tomography of microns-thick specimens with the high voltage electron microscope (HVEM) and the ultra-HVEM. In this work, we have investigated image quality of a tilted thick specimen by experiment and analysis. In a 3 MV ultra-HVEM, we obtained transmission electron images in amplitude contrast of 100 nm gold particles on the top surface of a tilted 5 μm thick amorphous epoxy-resin film. From line profiles of the images, we then measured and evaluated image blurring, contrast, and the signal-to-noise ratio (SNR) under different effective thicknesses of the tilted specimen and accelerating voltages of electrons. The variation of imaging blurring was consistent with the analysis based on multiple elastic scattering. When the effective thickness almost tripled, image blurring increased from â¼3 to â¼20 nm at the accelerating voltage of 3 MV. For the increase of accelerating voltage from 1 to 3 MV in the condition of the 14.6 μm effective thickness, due to the reduction of multiple scattering effects, image blurring decreased from â¼54 to â¼20 nm, and image contrast and SNR were both obviously enhanced by a factor of â¼3 to preferable values. The specimen thickness was shown to influence image quality more than the accelerating voltage. Moreover, improvement on image quality of thick specimens due to increasing the accelerating voltage would become less when it was further increased from 2 to 3 MV in this work.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Fang Wang, Hai-Bo Zhang, Meng Cao, Ryuji Nishi, Akio Takaoka,