Classical electron trajectory in scanning electron microscope mirror image method

1994 ◽  
Vol 76 (2) ◽  
pp. 806-809 ◽  
Author(s):  
H. Chen ◽  
H. Gong ◽  
C. K. Ong
2009 ◽  
Vol 87 (9) ◽  
pp. 973-980
Author(s):  
O. Hachicha ◽  
N. Ghorbel ◽  
A. Kallel ◽  
Z. Fakhfakh

For a better understanding of the physical mechanisms involved in insulators submitted to electron irradiation inside a scanning electron microscope, it is important to investigate charge trapping and detrapping. The commonly used technique to deduce the trapping ability and the motion process of electric charges is based on two complementary experimental methods: the scanning electron microscope mirror effect (SEMME) and the induced current measurement (ICM). In this paper, our study is devoted to the influence of temperature on the behavior of porcelain materials during electron injection time. To evaluate the geometry of the trapped charge distribution, a detailed analysis using the mirror image formation and its evolution is developed.


Author(s):  
Hassan N. Al-Obaidi ◽  
Imad H. Khaleel

A theoretical investigation have been presented to exploring the influence of electrons beam current on the electron mirror image deduced inside the scanning electron microscope (SEM). A rough mathematical expression for the electric potential that associated with electron beam is derived. The results clearly shows that the beam current could be used to enhance or conversely deteriorate the phenomena of mirror effect. So this work procedure may consider to be tool controllable of this phenomena for investigation purposes.


Author(s):  
Hiroshi Suga ◽  
Takafumi Fujiwara ◽  
Nobuhiro Kanai ◽  
Masatoshi Kotera

An image contrast given in the scanning electron microscope(SEM) is due to differences in a detected number of secondary electrons (SE) coming from the specimen surface. The difference arises from the topographic, compositional and voltage features at the specimen surface. Two kinds of approaches have been taken for the quantification of SE images. One is to simulate electron trajectories in vacuum toward the detector, assuming the typical angular and energy distributions of electrons emitted from the specimen surface. However, the typical angular and energy distributions are not always applicable if a topographic or a compositional feature is present at the surface. The other is to simulate electron trajectory in the specimen. It is possible to obtain angular, energy, and spatial distributions of electrons emitted from the specimen surface. However, in order to discuss the SEM contrast based on these data, one has to assume that, for example, all slow electrons (<50eV) may be collected by the SE detector, or fast electrons ((>50eV) electrons may take a straight trajectory in the vacuum specimen chamber of the SEM. In a practical SEM picture of, for example, an etch-pit, different crystallographic plane surface shows different contrast even if the angle of the primary electron incidence toward all those surfaces is the same. This is because of the acceptance of the signal detection system. In a present study we combined two electron trajectory simulations mentioned above and calculated electron trajectories both in and out of the specimen, to simulate the trajectory from the point of the signal generated until the signal is detected.Although several simulation models of electron scatterings in a specimen have been reported to estimate the SE intensity at the surface, the model should be available to trace low energy (<50eV) electron trajectories. The model used here is basically the same as that reported in previous papers, and only a brief explanation is given in the following. Here, we made several assumptions as; [l]the energy loss of the primary and excited fast electrons is proportion to the number of SEs generated in the specimen, [2]the generated SE has an energy distribution as described by the Streitwolf equation, [3]the energy of the generated SEs are transferred to free electrons of the atom by the elastic-binary-collision, then one SE excited by the primary electron produces a ternary electron after the collision, and each one of the SE and the ternary electron produces higher order electrons in a cascade fashion. The simulation continues until the energy of each electron is less than the surface potential barrier. Angular and energy distributions and number of electrons emitted at the surface agree quite well with each experimental result in a typical case.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


Author(s):  
C. T. Nightingale ◽  
S. E. Summers ◽  
T. P. Turnbull

The ease of operation of the scanning electron microscope has insured its wide application in medicine and industry. The micrographs are pictorial representations of surface topography obtained directly from the specimen. The need to replicate is eliminated. The great depth of field and the high resolving power provide far more information than light microscopy.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


Author(s):  
S. Takashima ◽  
H. Hashimoto ◽  
S. Kimoto

The resolution of a conventional transmission electron microscope (TEM) deteriorates as the specimen thickness increases, because chromatic aberration of the objective lens is caused by the energy loss of electrons). In the case of a scanning electron microscope (SEM), chromatic aberration does not exist as the restrictive factor for the resolution of the transmitted electron image, for the SEM has no imageforming lens. It is not sure, however, that the equal resolution to the probe diameter can be obtained in the case of a thick specimen. To study the relation between the specimen thickness and the resolution of the trans-mitted electron image obtained by the SEM, the following experiment was carried out.


Author(s):  
R. F. Schneidmiller ◽  
W. F. Thrower ◽  
C. Ang

Solid state materials in the form of thin films have found increasing structural and electronic applications. Among the multitude of thin film deposition techniques, the radio frequency induced plasma sputtering has gained considerable utilization in recent years through advances in equipment design and process improvement, as well as the discovery of the versatility of the process to control film properties. In our laboratory we have used the scanning electron microscope extensively in the direct and indirect characterization of sputtered films for correlation with their physical and electrical properties.Scanning electron microscopy is a powerful tool for the examination of surfaces of solids and for the failure analysis of structural components and microelectronic devices.


Sign in / Sign up

Export Citation Format

Share Document