|
|
Kontrast zrn na velmi nízkých energiích v REM
Pokorná, Zuzana ; Frank, Luděk
When lowering energy of incident electrons to 100 eV and less, the elastic scattering becomes heavily anisotropic while the inelastic scattering progressively drops off. Energy dependence of the reflected signal becomes then specific to the crystal orientation. The experiments with the imaging of the metal polycrystals were done in the SEM equipped by the cathode lens.
|
|
|
Metody přímého zobrazování hustoty stavů pomocí elektronů
Pokorná, Zuzana ; Frank, Luděk
Applicability of the SLEEM method for direct mapping of LDOS is the topic of the present study. The main issues include managing of the non-negligible angular aperture of the incident beam and even of the rocking connected with beam scanning over the field of view. These conditions require the contrast forming model to be reconsidered.
|
|
| |
|
|
Kontrast dopantu – otázka pro elektronovou mikroskopii
Frank, Luděk
Results obtained when imaging doped areas in silicon by means of various electron microscopical methods are reviewed. These include secondary electron imaging in the conventional SEM and SEM equipped with the cathode lens, imaging with very slow backscattered electrons by means of the cathode lens, and imaging in a photoelectron emission microscope. It is suggested that important role in the contrast formation plays local differences in the absorption of excited hot electrons on their trajectories toward surface.
|
|
|
Local density of states mapping using the reflection of very slow electrons
Pokorná, Zuzana
The aim of the work is performing a series of experiments in an ultra high vacuum electron microscope, demonstrating the inverse proportionality between the reflectance of very slow electrons and the local density of electron states bound to the incident wave. The work also aims to describe quantitatively the imaging of a doped region in the semiconductor surface layer.
|
|
|
Elektrostatický nízkoenergiový rastrovací elektronový mikroskop pro Augerovu analýzu
Romanovský, V. ; El Gomati, M. M. ; Frank, Luděk ; Müllerová, Ilona
A scanning low energy electron microscope (SLEEM) was realized with a cathode lens in which the negatively biased specimen is used as the cathode. In this arrangement, electrons pass through the microscope at high energy and are decelerated to low energy before landing on the sample. This design brings plenty of signal even in the landing energy range of tens or units of eV. However, the use of the primary electrons with low energy brings some problems e.g. low source brightness, increased aberrations and sensitivity to stray fields. The scanning Auger microscopy (SAM) is well-established experimental method. A combination of SAM and SLEEM in one device would therefore provide a sufficient tool to solve the problems inherent in these individual methods. Although much has already been achieved in the area of detection of slow electrons, none of the methods currently known is suitable to be built into a scanning illumination column for Auger microprobe analysis
|
guest ::
