“Interpretation of Micrographs from a Scanning Electron Microscope”

Author(s):  
E. Eichen ◽  
D. R. Fitchmun ◽  
L. R. Sefton

In the past two years, there has been a great increase in interest in the scanning electron microscope as a research tool. Coupled with this has been a large increase in the number of instruments being used throughout the world. The reasons for this popularity stems from the unique abilities of this form of in strumentation which include: (a) a large depth of field which allows one to view a very rough surface; (b) a minimal requirement of specimen preparation; and (c) its ability to make use of voltage contrast in the study of semiconductors.

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):  
Emil Bernstein

An interesting method for examining structures in g. pig skin has been developed. By modifying an existing technique for splitting skin into its two main components—epidermis and dermis—we can in effect create new surfaces which can be examined with the scanning electron microscope (SEM). Although this method is not offered as a complete substitute for sectioning, it provides the investigator with a means for examining certain structures such as hair follicles and glands intact. The great depth of field of the SEM complements the technique so that a very “realistic” picture of the organ is obtained.


Author(s):  
M. Osumi ◽  
N. Yamada ◽  
T. Nagatani

Even though many early workers had suggested the use of lower voltages to increase topographic contrast and to reduce specimen charging and beam damage, we did not usually operate in the conventional scanning electron microscope at low voltage because of the poor resolution, especially of bioligical specimens. However, the development of the “in-lens” field emission scanning electron microscope (FESEM) has led to marked inprovement in resolution, especially in the range of 1-5 kV, within the past year. The probe size has been cumulated to be 0.7nm in diameter at 30kV and about 3nm at 1kV. We have been trying to develop techniques to use this in-lens FESEM at low voltage (LVSEM) for direct observation of totally uncoated biological specimens and have developed the LVSEM method for the biological field.


Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Terrence W. Reilly

Although the first commercial scanning electron microscope (SEM) was introduced in 1965, the limited resolution and the lack of preparation techniques initially confined biological observations to relatively low magnification images showing anatomical surface features of samples that withstood the artifacts associated with air drying. As the design of instrumentation improved and the techniques for specimen preparation developed, the SEM allowed biologists to gain additional insights not only on the external features of samples but on the internal structure of tissues as well. By 1985, the resolution of the conventional SEM had reached 3 - 5 nm; however most biological samples still required a conductive coating of 20 - 30 nm that prevented investigators from approaching the level of information that was available with various TEM techniques. Recently, a new SEM design combined a condenser-objective lens system with a field emission electron source.


Author(s):  
Zhang zhaohua ◽  
Luo Dong ◽  
Guo Yisong

Since early 1970's the use of cold stage on SEM for observation of hydrated samples in their natural state has become more and more popular despite its high cost. Experiences gained from earlier experiments indicate that a successful design should incorporate thefollowing features:1. The specimen temperature should be below −135°C (the recrystallization point of water), lower the temperature, better the results.2. The frozen specimen, the cold block in the specimen preparation chamber, as well as the cold stage should be kept under vacuum at all times to keep them frost free.3. Different specimen preparation processes such as fracturing, coating and sublimation should be possible in one compact preparation chamber .


Author(s):  
Julien Goxe ◽  
Béatrice Vanhuffel ◽  
Marie Castignolles ◽  
Thomas Zirilli

Abstract Passive Voltage Contrast (PVC) in a Scanning Electron Microscope (SEM) or a Focused Ion Beam (FIB) is a key Failure Analysis (FA) technique to highlight a leaky gate. The introduction of Silicon On Insulator (SOI) substrate in our recent automotive analog mixed-signal technology highlighted a new challenge: the Bottom Oxide (BOX) layer, by isolating the Silicon Active Area from the bulk made PVC technique less effective in finding leaky MOSFET gates. A solution involving sample preparation performed with standard FA toolset is proposed to enhance PVC on SOI substrate.


Author(s):  
Hadi M. Hamza Al-Mayali ◽  
Hind A. Abdul Kadhim

Introduction: Echinococcosis and hydatidosis caused by the metacestode of Echinococcus granulosus are among the most important zoonotic diseases in the world. This study aims to study the ultrastructure of fertile hydatid cysts that infect humans using a scanning electron microscope (SEM). Materials and Methods: Twenty samples of human fertile hydatid cysts were collected from the human liver and lung after performing surgery operations and examined with an SEM. Results: The results of the electron microscopy with different magnifications revealed that the laminated layer (LL) consists of sheets that appeared more compact and aligned. The brood capsules appeared, consisting of a net of finger-shaped structures that emerged from bulges of various sizes and shapes. Conclusion: Under a transmission electron microscope, it was found that the LL had a coherent and flexible structure, settling on a three-dimensional microscopic network of hydrophilic fibers, with high humidity. These fibers were arranged irregularly and had a diameter of about 10 nm; therefore, the fibers adjacent to the germinal layer (GL) were possibly attached to microtriches of tegument, which reached a thickness of 1 mm in the LL.


2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.


Sign in / Sign up

Export Citation Format

Share Document