Introduction of the electron microscope

Abstract

This short book mainly describes the ultrahigh-vacuum (UHV) technology in JEOL electron microscopes. There are two types of electron microscopes, one the transmission electron microscope (TEM) and the other scanning electron microscope, accurately speaking, scanning secondary-electron microscope (SEM). From the view point of vacuum technology, it is much difficult to evacuate the complex column of TEM to UHV, compared in the case of SEM. Therefore, we, the engineers engaging in vacuum technology, mainly made efforts in improving the vacuum in TEMs. At the same time, we naturally engaged in improving the vacuum systems of SEM and other scientific instruments such as X-ray microanalyzer (XMA) and Auger-electron spectrometer (AES). Additionally speaking, SEM equipped with the field emission (FE) electron source earlier than TEM did, and AES was a UHV instrument from its birth. The large sputter ion pump (SIP) for the AES chamber must pump Argon gas stably for depth-profile analysis. The TEM has been developing to the analytical EM (AEM) by having an X-ray analysis function, and to the scanning EM (STEM) by having a scanning function. It would be better to introduce the principle of EM and the construction of the microscope column briefly. The principles SEM, XMA, and AES are also presented briefly.