Technology for Fundamental Improvement of an Extremely Low-Quality Video Signal for Use in Fine Focusing and Astigmatism Correction in Scanning Electron Microscopy

Figure 2

Confirmation of the quality of the just-focused images and graphs for focusing evaluation in the case without use of noise reduction technologies. (a) Flat specimen and its specimen stub, which were coated with a thick Au film. (b) SEM image of the flat thick film acquired at 26 pA. (c) Image of the specimen stub acquired at 26 pA. (d) Image of the film acquired at 8 pA. (e) Image of the film acquired at 2 pA. (b–e) Graphs showing the changes in the SNR during the focusing operation corresponding to each condition. The bar represents 0.7 μm.