• Journal of the Korean Society for Precision Engineering
• /
• v.25 no.4
• /
• pp.53-60
• /
• 2008

Electron detectors used in scanning electron microscope accept electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. Electron detector is one of the key components dominating the performance of scanning electron microscope so that the development of electron detectors having high performance is indispensable to acquire high quality images using scanning electron microscope. In this paper, we designed and manufactured an electron detector and conducted a couple of image capture experiments using it. In particular, scintillator which generates light photons when it is struck by high-energy electrons was manufactured and experimental studies on the optimization of manufacturing condition was carried out. From experiments to evaluate the performance of our detector, it was verified that the performance of our detector is equivalent to or better than that of the conventional one.

• Applied Microscopy
• /
• v.33 no.2
• /
• pp.93-104
• /
• 2003

Since the Ptolemaeos' discovery that glass has magnifying power, human desire to see the unseen with naked eyes has lead to the inventions of a series of microscopes. Since the Janssen's first compound microscope in 1595, through the Abbe's non-aberration microscopy, various microscopes using different principles are now being used in various biomedical researches. The discovery of electron by Thompson in 1897 has lead to the first invention of microscope using electron as an illumination source, the electron microscope, in 1931. Now we can see the objects as close as 0.05 nm using 1 MV FE-TEM constructed in 2000. In this review, the authors reviewed the predecessors efforts to develop better microscopes.

• Carbon letters
• /
• v.7 no.3
• /
• pp.166-170
• /
• 2006

Silicon carbide whiskers ($SiC_w$) having the diameter in the range of 20-80 nm were synthesised from coconut fibres through sol-gel process. The coconut fibres were impregnated with tetraethoxysilane and methyltriethoxysilane derived sol and pyrolyzed at $1400^{\circ}C$ in argon. X-ray of the pyrolyzed samples showed the formation of ${\beta}$-SiC.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.9-14
• /
• 2005

The nature of the signals collected by an SEM(Scanning Electron Microscope) in order to form images are all dependent on the detector used to collect them, and the quality of an acquired image is strongly influenced by detector performance. Therefore, the development of detector with high performance is very important in pulling up the resolution of SEM This study presents the secondary electron detector for use in scanning electron microscope, electric circuit and I/V conversion circuit for driving that detector.

• Applied Microscopy
• /
• v.2 no.1
• /
• pp.39-46
• /
• 1972

There are many kinds of microscopes suitable for general studies; optical microscopes(OM), conventional transmission electron microscopes (TEM), and scanning electron microscopes(SEM). The optical microscopes and the conventional transmission electron microscopes are very familiar. The images of these microscopes are directly formed on an image plane with one or more image forming lenses. On the other hand, the image of the scanning electron microscope is formed on a fluorescent screen of a cathode ray tube using a scanning system similar to television technique. In this paper, the features and some applications of the scanning electron microscope will be discussed briefly. The recently available scanning electron microscope, combining a resolution of about $200{\AA}$ with great depth of field, is favorable when compared to the replica technique. It avoids the problem of specimen damage and the introduction of artifacts. In addition, it permits the examination of many samples that can not be replicated, and provides a broader range of information. The scanning electron microscope has found application in diverse fields of study including biology, chemistry, materials science, semiconductor technology, and many others. In scanning electron microscopy, the secondary electron method. the backscattererd electron method, and the electromotive force method are most widely used, and the transmitted electron method will become more useful. Change-over of magnification can be easily done by controlling the scanning width of the electron probe. It is possible. to continuously vary the magnification over the range from 100 times to 1.00,000 times without readjustment of focusing. Conclusion: With the development of a scanning. electron microscope, it is now possible to observe almost all-information produced through interactions between substances and electrons in the form of image. When the probe is properly focused on the specimen, changing magnification of specimen orientation does not require any change in focus. This is quite different from the conventional transmission electron microscope. It is worthwhile to note that the typical probe currents of $10^{-10}$ to $10^{-12}\;{\AA}$ are for below the $10^{-5}$ to $10^{-7}\;{\AA}$ of a conventional. transmission microscope. This reduces specimen contamination and specimen damage due to heatings. Outstanding features of the scanning electron microscope include the 'stereoscopic observation of a bulky or fiber specimen in high resolution' and 'observation of potential distribution and electromotive force in semiconductor devices'.

• 한국전자현미경학회:학술대회논문집
• /
• 1998.05a
• /
• pp.32-33
• /
• 1998

• Applied Microscopy
• /
• v.46 no.3
• /
• pp.155-159
• /
• 2016

This paper analyses the relationship between the distribution of a dielectric layer on the apex of a metal field electron emitter and the distribution of electron emission. Emitters were prepared by coating a tungsten emitter with a layer of epoxylite resin. A high-resolution scanning electron microscope was used to monitor the emitter profile and measure the coating thickness. Field electron microscope studies of the emission current distribution from these composite emitters (Tungsten-Clark Electromedical Instruments Epoxylite resin [Tungsten/CEI-resin emitter]) have been carried out. Two forms of image have been observed: bright single-spot images, thought to be associated with a smooth substrate and a uniform dielectric layer; and multi-spot images, though to be associated with irregularity in the substrate or the dielectric layer.

• Applied Microscopy
• /
• v.25 no.2
• /
• pp.80-87
• /
• 1995

An analytical electron microscope system has been widely used in biology, medicine, veterinary medicine, agriculture, and materials, etc. nowadays in Korea Market since mid of 1980's. How to install and to choose the equipments? The answers are which prerequisites are needed to us. The purpose is going to introduce the prerequisites of the pre-installation and installation of Philips analytical electron microscope(CM 12/STEM and SEM 515, Philips, The Netherlands) in the National Institute of Safety Research, Seoul and to discuss the check-subjects. The check-subjects in the pre-installation and installation are more than 24. The influence of magnetic fields, mechanical vibrations, earth is crucial factor for decision of installation site. The areas of our electron microscope center are $105.6m^2$ and have the Automatic Image Analyzer System(IBAS, Kontron Co., Germany) connecting to the SEM mode. Water temperature was controlled by the NESLAB recirculatory chillers(NESLAB Co., U.S.A.).

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.1875-1878
• /
• 2005

It is not efficient and scarcely out of the question to use commercial expensive electron beam lithography system widely used for semiconductor fabrication process for the manufacturing application field of various devices in the small business scope. Then scanning electron microscope based electron beam machining system is maybe regarded as a powerful model can be used for it simply. To get a complete suite of thus proper system, column unit build up with electron beam gun head unit is necessarily required more than anything else to modify scanning electron microscope. In this study, various components included ceramic isolation plate and main body which are essentially constructed for electron beam gun head unit are designed and manufactured. And this electron beam gun head unit will be used for next connected study in the development step of scanning electron microscope based electron beam machining system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.04a
• /
• pp.513-517
• /
• 2004

The nature of the signals collected by an SEM(Scanning Electron Microscope) in order to form images are all dependent on the detector used to collect them, and the quality of an acquired image is strongly influenced by detector performance. Therefore, the development of detector with high performance is very important in pulling up the resolution of SEM. In this article, electron beam-specimen interactions, the detection principle of secondary electrons and backscattered electrons, and the structure of a conventional detector are described. The structure of an experimental apparatus for the future study on our hopeful novel electron detector is presented as well.