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Detection of angular distribution of the signal electrons in VLESEM
Horáček, Miroslav
The aim of this work is to design a detector for the angle and energy-selective detection of signal electrons in very low energy scanning electron microscopy (VLESEM), based on the directly electron-bombarded CCD sensor (EBCCD). The planar CCD sensor is very suitable for conversion of the area information carried by impinging electrons of the signal beam into the electrical signal that can be further processed.
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Performance of detector elements for electron microscopes
Schauer, Petr ; Autrata, Rudolf
Signal processing in scanning and transmission elecrtron microscopes is analysed in this paper. Distinguished are criteria of principal and commercial significance, and problematic parameters of different systems are highlighted. The most important properties of scintillation detection systems and imaging screens are discussed more in detail. For the scintillation detector, the analysis of conversion of the signal to photons, their transport from emission centres to PMT photocathode, and their conversion to photoelectrons is carried out. For the imaging screen, attention is focused on the spectral matching and spatial resolution.
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Test Specimens for SEM
Matějka, František ; Ryzí, Z.
In most applications SEM devices are utilized in the area of magnification quite far from the high limit. For such cases we prepare objects interesting for SEM by using special techniques of microfabrication. Those objects can be called test patterns. Compared with natural objects, they have an advantage: their geometry and dimensions are determined with high precision. Another advantage may be that the test pattern can be created from materials with well known properties. In our laboratories we prepare test specimens using electron-beam lithography and the anisotropic etching of silicon and using holographic techniques. We have designed the topography of anisotropically etched measuring test specimen ".mu.-scale".In most applications SEM devices are utilized in the area of magnification quite far from the high limit. For such cases we prepare objects interesting for SEM by using special techniques of microfabrication. Those objects can be called test patterns. Compared with natural objects, they have an advantage: their geometry and dimensions are determined with high precision. Another advantage may be that the test pattern can be created from materials with well known properties. In our laboratories we prepare test specimens using electron-beam lithography and the anisotropic etching of silicon and using holographic techniques. We have designed the topography of anisotropically etched measuring test specimen ".mu.-scale".
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Imaging of semiconductor structures in environmental SEM
Romanovský, Vladimír ; Hutař, Otakar
The charging effects are encountered very often when the semiconductor specimens are observed. There are several possibilities how to eliminate these undesirable phenomena. One of the newest methods how to suppress charging of specimens is environmental scanning electron microscopy (ESEM). Ionisation of gas molecules caused by impacts of primary beam electrons and signal electrons in the close vicinity of the specimen surface removes the surface charge. The ionisation detectors used in ESEM enable one to obtain similar information as in classical SEM.
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Combined scintillation and ionisation detectors for environmental scanning electron microscopes
Romanovský, Vladimír ; Autrata, Rudolf
One of the recent directions in the field of scanning electron microscopy deals with observation of specimens at higher pressures in the specimen chamber. Owing to the presence of the gaseous medium, charging effects are suppressed for specimens of insulation character, and at the same time the observation of biological specimens without their prior treatment is made possible. The constructed combined scintillation and ionisation detector extends the applications of these microscopes and enables copmarison of behaviour and properties of both detectors.
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