亚洲AV日韩AV无码污污网站_亚洲欧美国产精品久久久久久久_欧美日韩一区二区视频不卡_丰满无码人妻束缚无码区_久爱WWW成人网免费视频


首頁 -> 登錄 -> 注冊(cè) -> 回復(fù)主題 -> 發(fā)表主題
光行天下 -> 光電資訊及信息發(fā)布 -> 掃描電鏡SEM [點(diǎn)此返回論壇查看本帖完整版本] [打印本頁]

探針臺(tái) 2019-09-27 10:56

掃描電鏡SEM

掃描電鏡SEM (Scanning Electron Microscope) was designed for inspecting the topographies of specimens at very high magnifications. Currently the advanced FESEM (Field Emission Scanning Microscopes) can go to magnifications as high as 300,000X. Due to the operation flexibilities and good imaging capabilities, SEM has been widely used to inspect sample Topographies and Morphologies. >Q\Kc=Q|  
+1!iwmch>  
During SEM inspection, the focused energetic electron beam is scanning on sample surface being inspected, resulting in the transfer of energy to the spot focused. These injected bombarding electrons, also referred to as primary electrons, dislodge electrons from the specimen itself. The dislodged electrons, also known as secondary electrons, are attracted and collected by a positively biased grid or detector, and then translated into a signal. After signal amplification and system analysis, these signals will be transmitted into images of sample topography, and revealed on the screen. `.W2t5 Y  
V}#X'~Ob  
With assistance of EDX, SEM can also do elemental composition analysis with spot size as small as 1um. EDX analysis is useful in identifying materials and contaminants, as well as estimating their relative concentrations on the surface of the specimen. $