Visualisation of Electrically Active Areas Using Electron Holography

2002 ◽  
Author(s):  
U. Muehle ◽  
A. Lenk ◽  
M. Lehmann ◽  
H. Lichte
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Electron Holography ◽  
Transmission Electron ◽  
Structural Details ◽  
Different Types ◽  
High Level ◽  
Technical Solutions

Abstract In accordance with the predictions of the International Semiconductor Association, a further decrease in the structural widths of semiconductor devices is expected. For an in-depth characterization of actual structural details, the transmission electron microscopy (TEM)-technique is becoming more and more significant. An urgent requirement is in the visualization of dimensions of the doped regions and estimation of p-n-junctions profile with a high level spatial resolution. The off-axis electron holography, a special TEM-technique, is able to visualize electrically active areas in semiconductors. This article describes a way to achieve sample preparation for TEM-holography from actual memory products and also provides an idea of the potential of this technique for semiconductor failure analysis. It shows that different types and sizes of FET's and testing structures could be visualized by focusing on the physical basics, technical solutions, and sample preparation.

Characterization of cellular development and fatty acid accumulation in thraustochytrid Aurantiochytrium strains of Taiwan

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Natarajan Velmurugan ◽  
Yesupatham Sathishkumar ◽  
Shashanka Sonowal ◽  
Ka-Lai Pang ◽  
Yang Soo Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Flow Cytometry ◽  
Cell Growth ◽  
Intracellular Lipid ◽  
Fatty Acid Accumulation ◽  
Transmission Electron ◽  
Intracellular Lipid Accumulation ◽  
High Level

Abstract Long-chain saturated and polyunsaturated fatty acids of two new thraustochytrid isolates cultured from Taiwan mangroves, Aurantiochytrium sp. IMB169 and Aurantiochytrium sp. IMB171, were characterized through their cell growth and development in relation to their intracellular lipid accumulation using transmission electron microscopy. Flow cytometry in combination with the lipophilic fluorescent dye BODIPY 505/515 was used to stain and characterize intracellular lipid bodies in the two isolates. The transmission electron microscopy and flow cytometry analyses revealed a progressive accumulation of lipid products in IMB169 and IMB171. Further, selective BODIPY stained cells were successfully separated and enriched using flow cytometry at single cell level. Among the two isolates, IMB169 was found to produce a high level of docosahexaenoic acid. The qualitative and analytical results obtained using electron microscopy and flow cytometry studies were validated by gas chromatography (GC). In addition, a quantitative baseline was established using cell growth, flow cytometry and GC analyses for developing an efficient bioprocessing methodology to selectively enrich thraustochytrids phenotypes with desirable characteristics.

scholarly journals Characterization of mouse spermatogonia by transmission electron microscopy

Reproduction ◽  
2002 ◽  
pp. 567-577 ◽  
Author(s):  
H Chiarini-Garcia ◽  
LD Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
B Cells ◽  
Nuclear Envelope ◽  
Type B ◽  
Intermediate Type ◽  
Functional Studies ◽  
Transmission Electron ◽  
Different Types

Characteristics of the various type A, intermediate (In) and B spermatogonia were determined in C57BL/6J mice using transmission electron microscopy. Spermatogonia were photographed at all stages of the cycle of the seminiferous epithelium. Over 450 images were taken. Spermatogonia could be classified into As, Apr, Aal, A1 cells, A2 cells, A3 cells, A4 cells, intermediate type and type B cells primarily on the basis of nuclear and nucleolar characteristics. The most primitive spermatogonia (As, Apr, Aal) had mottled chromatin; A1 cells contained homogeneously finely granular chromatin throughout the nucleus; A2, A3, A4 and intermediate type spermatogonia had progressively increasing amounts of chromatin encrusting the nuclear envelope; type B spermatogonia had less heterochromatin along the nuclear envelope, although the particles were more dense and rounded than in intermediate type spermatogonia. Mitochondrial size and position of Golgi complexes varied in different types of spermatogonia. These data show that types of spermatogonia can be differentiated such that these characteristics can be used in functional studies.

Improving transmission electron microscopy characterization of semiconductors by minimizing sample preparation artifacts

1992 ◽  
Vol 70 (10-11) ◽  
pp. 875-880 ◽  
Author(s):  
J. P. McCaffrey ◽  
G. I. Sproule ◽  
R. Sargent
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Ion Milling ◽  
Transmission Electron ◽  
Transmission Electron Microscopy Characterization ◽  
Silicon Based ◽  
Microscopy Characterization ◽  
Preparation Techniques

Techniques employed for the preparation of transmission electron microscopy (TEM) samples can introduce artifacts that obscure subtle detail in the materials being studied. Traditional semiconductor sample preparation techniques rely heavily on ion milling, which leaves amorphous layers on ion milled surfaces and some intermixing across interfaces, thus degrading the TEM images of these samples. Experimental results of the extent of this amorphization and intermixing are presented for silicon-based semiconductor samples, and methods to minimize these effects are suggested. These methods include variations in ion milling parameters that reduce the extent of the artifacts, and improvements in the small-angle cleavage technique that eliminate these artifacts completely.

scholarly journals TEM Sample Preparation: An Interdisciplinary Website

2009 ◽  
Vol 17 (2) ◽  
pp. 38-41 ◽  
Author(s):  
Jeanne Ayache ◽  
Luc Beaunier ◽  
Jacqueline Boumendil ◽  
Gabrielle Ehret ◽  
Danièle Laub
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Material Science ◽  
International Community ◽  
Central Importance ◽  
Transmission Electron ◽  
Characterization Of Materials ◽  
Preparation Techniques

Sample preparation is of central importance for the characterization of materials by transmission electron microscopy (TEM). As a guide to researchers seeking practical help on the use of all types of TEM sample preparation techniques, we have created an Internet website. This website has been designed in French and is now translated into English. The website is accessible free of charge.The TEMSAMPREP website, figure 1 http://temsamprep.in2p3.fr/, is the result of a synergistic effort of an atypical team of five electron microscopy scientists having different research specialties in physics, mineralogy, material science, and biology. They shared five years of human adventure in creating the website to transmit their 30 years of TEM experience to the international community.

Transmission Electron Microscopy of the Retina: A Method for Sample Preparation and Evaluation

2020 ◽  
pp. 019262332095412
Author(s):  
Christopher M. Hayden ◽  
Emily K. Meseck
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Sample Preparation ◽  
Clinical Examination ◽  
Spherical Shape ◽  
Disease Models ◽  
Posterior Aspect ◽  
Orientation Imaging ◽  
Transmission Electron

Ultrastructural pathology is critical in the morphologic evaluation and characterization of subcellular structures in nonclinical toxicity and efficacy studies. In murine models of ophthalmologic disease, clinical examination is typically paired with other techniques like electroretinography (ERG) and/or optical coherence tomography (OCT) to more fully characterize a finding. High-quality transmission electron microscopy (TEM) can provide a critical, image-based link between these approaches, providing greater confidence in interpretation of ERG or OCT results. In addition to characterization of disease models, TEM can provide detailed visualization of retinal changes identified by clinical examination or light microscopy in nonclinical toxicity studies. The spherical shape of the eye presents unique challenges for trimming, orientation, imaging, and evaluation by TEM. The varied components of the eye require specialized approaches for embedding to facilitate successful sectioning. Controlling for the orientation of the retina is critical to consistent evaluation, driving the need for an improved method of embedding this unique and complex organ. The authors describe a method of sample preparation resulting in optimal orientation of the posterior aspect of murine eyes (rat and mouse) for TEM of the neural retina, Bruch’s membrane and/or choroid, with examples from mouse ophthalmic disease models.

scholarly journals Towards Cellular Ultrastructural Characterization in Organ-on-a-Chip by Transmission Electron Microscopy

Applied Nano ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 289-302
Author(s):  
Adrianna Glinkowska Mares ◽  
Natalia Feiner-Gracia ◽  
Yolanda Muela ◽  
Gema Martínez ◽  
Lidia Delgado ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endothelial Cells ◽  
Sample Preparation ◽  
Preparation Method ◽  
Sample Preparation Method ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Organ On A Chip

Organ-on-a-chip technology is a 3D cell culture breakthrough of the last decade. This rapidly developing field of bioengineering intertwined with microfluidics provides new insights into disease development and preclinical drug screening. So far, optical and fluorescence microscopy are the most widely used methods to monitor and extract information from these models. Meanwhile transmission electron microscopy (TEM), despite its wide use for the characterization of nanomaterials and biological samples, remains unexplored in this area. In our work we propose a TEM sample preparation method, that allows to process a microfluidic chip without its prior deconstruction, into TEM-compatible specimens. We demonstrated preparation of tumor blood vessel-on-a-chip model and consecutive steps to preserve the endothelial cells lining microfluidic channel, for the chip’s further transformation into ultrathin sections. This approach allowed us to obtain cross-sections of the microchannel with cells cultured inside, and to observe cell adaptation to the channel geometry, as well as the characteristic for endothelial cells tight junctions. The proposed sample preparation method facilitates the electron microscopy ultrastructural characterization of biological samples cultured in organ-on-a-chip device.

scholarly journals Characterization of Localized Degradation in Reverse-Biased GaN HEMTs by Scanning Transmission Electron Microscopy and Electron Holography

2010 ◽  
Vol 16 (S2) ◽  
pp. 800-801
Author(s):  
DA Cullen ◽  
DJ Smith ◽  
A Stocco ◽  
G Meneghesso ◽  
E Zanoni ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Electron Holography ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Gan Hemts

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

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