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Scanning Electron Microscopy (SEM)

概要

Source: Laboratory of Dr. Andrew J. Steckl — University of Cincinnati

A scanning electron microscope, or SEM, is a powerful microscope that uses electrons to form an image. It allows for imaging of conductive samples at magnifications that cannot be achieved using traditional microscopes. Modern light microscopes can achieve a magnification of ~1,000X, while typical SEM can reach magnifications of more than 30,000X. Because the SEM doesn’t use light to create images, the resulting pictures it forms are in black and white.

Conductive samples are loaded onto the SEM’s sample stage. Once the sample chamber reaches vacuum, the user will proceed to align the electron gun in the system to the proper location. The electron gun shoots out a beam of high-energy electrons, which travel through a combination of lenses and apertures and eventually hit the sample. As the electron gun continues to shoot electrons at a precise position on the sample, secondary electrons will bounce off of the sample. These secondary electrons are identified by the detector. The signal found from the secondary electrons is amplified and sent to the monitor, creating a 3D image. This video will demonstrate SEM sample preparation, operation, and imaging capabilities.

手順

1. Preparation of the Sample

Place sample onto sample stub. If necessary, carbon tape may be used to adhesively bond the sample to the stub.
Place the sample into a gold sputtering system. Using a mini-gold sputter, sputter gold for 30 s at ~ 70 mTorr pressure. A different gold layer thickness may be necessary depending on the geometry of the sample. More rough or porous surface requires a longer sputtering time.
Remove stub from gold sputtering system.

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結果

The SEM, seen in Figure 2a, has been used for making measurements and acquiring sample photos. The sample consisted of sodium chloride (NaCl) salt. It was placed onto the stub as seen in Figure 2b, then a few nanometers of gold was sputtered onto it to make it conductive. The conductive sample was then placed into the SEM sample area as seen in Figure 2c.

SEM images were obtained at 50X, 200X, 500X, 1,000X, and 5,000X magnification levels as s

申請書と概要

The SEM is a very powerful tool that is common in most research institutions because of its ability to image any object that is conductive, or has been treated with a conductive coating. The SEM has been used to image objects such as semiconductor devices,² biological membranes,³ and insects,⁴ among others. We have also used the SEM to analyze nanofibers and paper-based materials, biomaterials, micropatterned structures. Of course, there are materials, such as liquids, that can’t be

参考文献

Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L., Michael, J. Scanning Electron Microscopy and X-ray Microanalysis. 3^rd Ed. Springer, New York, NY. (2003).
Purandare, S., Gomez, E.F., Steckl, A.J. High brightness phosphorescent organic light emitting diodes on transparent and flexible cellulose films. Nanotechnology. 25, 094012 (2014).
Masuda, Y., Yamanaka, N., Ishikawa, A., Kataoka, M., Aral, T., Wakamatsu, K., Kuwahara, N., Nagahama, K., Ichikawa, K., Shimizu, A. Glomerular basement membrane injuries in IgA nephropathy evaluated by double immunostaining for a5(IV) and a2(IV) chains of type IV collagen and low-vacuum scanning electron microscopy. Clinical and Experimental Nephrology. 1-9. (2014).
Kang, J.H., Lee, Y.J., Oh, B.K., Lee, S.K. Hyun, B.R. Lee, B.W, Choi, Y.G., Nam, K.S., Lim, J.D. Microstructure of the water spider (Argyroneta aquatic) using the scanning electron microscope Journal of Asia-Pacific Biodiversity. 7 484-488 (2014).

タグ

Scanning Electron Microscopy SEM SEM Technique Electron Beam Surface Structure Analysis Chemical Composition Analysis Light Microscopy Limitations Diffraction Lateral Resolution Magnification Sub nanometer Resolution Depth Of Field SEM In Chemistry And Material Analysis Nanoscale Analysis SEM Sample Preparation SEM Operation Conductive Samples

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