Thermal- and acoustic-wave techniques in scanning electron microscopy

1986 ◽  
Vol 64 (9) ◽  
pp. 1238-1246 ◽  
Author(s):  
Ludwig Josef Balk

Since their introduction in 1980, thermal- and acoustic-wave techniques utilizing electron-beam excitation, denoted in the following as scanning electron acoustic microscopy (SEAM), have developed to include methods in the realm of scanning electron microscopy (SEM), giving additional and important information on material parameters compared with other SEM techniques. However, the SEAM method still has shortcomings, both theoretically and experimentally. New theories have to consider various principal sound-generation mechanisms, especially for semiconductors, ceramics, and ferromagnets. Furthermore, they must include three-dimensional and time-resolved calculations. From experimental evidence there is obviously the need for additional consideration of nonlinear signal generation. The theoretical discussion has to be supported by experiments; both phase analysis of the SEAM signal with respect to the electron-beam wave form and evaluation of the temporal SEAM behaviour are important for revealing information about the specimen. With special detectors, in situ experiments can be carried out for varying process parameters, as shown for the investigation of steel sheets. The SEAM performance has to be compared to other SEM modes by simultaneous experiments, especially for applications to semiconductors. Finally, extension to gigahertz frequencies and use of tomographic methods should increase the importance of SEAM in future.

Author(s):  
S. Cargill

Electron-acoustic microscopy is a mode of ultrasonic imaging in scanning electron microscopy for which image contrast arises primarily from spatial variations in the elastic and thermal properties of a specimen, e.g., its resistance to bending, resistance to heat flow, and volume expansion on heating. Electron-acoustic (EA) microscopy differs from conventional scanning electron microscopy in that the electron beam is chopped at kHz or MHz rates, and a piezoelectric transducer bonded to the specimen is used to detect ultrasonic signals which are generated thermoelastically within the specimen. A scanned, magnified image of the specimen is formed using the rectified output of this transducer, in place of the usual secondary or back scattered electron signal. This technique provides near-surface and subsurface information which is not accessible in other modes of SEM imaging. The experiments described here were performed with a Cambridge Stereoscan S4-10 SEM in which the electron beam was chopped electrostatically by deflector plates located below the second condenser lens.


Author(s):  
Linda C. Sawyer

Scanning electron microscopy (SEM) has become an analytical tool widely used in universities, industrial laboratories and modern plants in applications ranging from fundamental research and applied research to quality control. The SEM provides important and insightful observations, in the form of three dimensional images of bulk materials and surfaces, which provide input to conduct process-structure-properties studies of polymer materials. SEM analysis requires knowledge of the instruments, image formation and specimen preparation methods.Consideration must be given to the interaction of the electron beam with the specimen, image formation and the effect of the electron beam on the specimen, e.g. beam damage. Scanning electron microscopy has been described and SEM of polymers has been reviewed. The essential feature of a scanning microscope is that the image is formed point by point, by scanning a probe across the specimen. The probe of an SEM is a focused electron beam and a detected signal is displayed as a TV type image.


Author(s):  
Valerio Sanna Valle ◽  
Guy Perez ◽  
Guillaume Bascoul ◽  
Helene Chauvin ◽  
Benoît Viallet ◽  
...  

Abstract Electron Beam Induced Current is a powerful tool for Scanning Electron Microscopy (SEM) imaging mode. In this paper, the history and evolution of this technique are discussed. Some important defects are presented as well as their technological interpretation. A new custom amplifier is presented and its implementation in Time Resolved EBIC (TREBIC) is also proposed, the main differences with EBIC are pointed out.


Author(s):  
Jane A. Westfall ◽  
S. Yamataka ◽  
Paul D. Enos

Scanning electron microscopy (SEM) provides three dimensional details of external surface structures and supplements ultrastructural information provided by transmission electron microscopy (TEM). Animals composed of watery jellylike tissues such as hydras and other coelenterates have not been considered suitable for SEM studies because of the difficulty in preserving such organisms in a normal state. This study demonstrates 1) the successful use of SEM on such tissue, and 2) the unique arrangement of batteries of nematocysts within large epitheliomuscular cells on tentacles of Hydra littoralis.Whole specimens of Hydra were prepared for SEM (Figs. 1 and 2) by the fix, freeze-dry, coat technique of Small and Màrszalek. The specimens were fixed in osmium tetroxide and mercuric chloride, freeze-dried in vacuo on a prechilled 1 Kg brass block, and coated with gold-palladium. Tissues for TEM (Figs. 3 and 4) were fixed in glutaraldehyde followed by osmium tetroxide. Scanning micrographs were taken on a Cambridge Stereoscan Mark II A microscope at 10 KV and transmission micrographs were taken on an RCA EMU 3G microscope (Fig. 3) or on a Hitachi HU 11B microscope (Fig. 4).


Author(s):  
R. I. Johnsson-Hegyeli ◽  
A. F. Hegyeli ◽  
D. K. Landstrom ◽  
W. C. Lane

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).


Author(s):  
David Joy ◽  
James Pawley

The scanning electron microscope (SEM) builds up an image by sampling contiguous sub-volumes near the surface of the specimen. A fine electron beam selectively excites each sub-volume and then the intensity of some resulting signal is measured. The spatial resolution of images made using such a process is limited by at least three factors. Two of these determine the size of the interaction volume: the size of the electron probe and the extent to which detectable signal is excited from locations remote from the beam impact point. A third limitation emerges from the fact that the probing beam is composed of a finite number of discrete particles and therefore that the accuracy with which any detectable signal can be measured is limited by Poisson statistics applied to this number (or to the number of events actually detected if this is smaller).


2018 ◽  
Author(s):  
Lo Chea Wee ◽  
Tan Sze Yee ◽  
Gan Sue Yin ◽  
Goh Cin Sheng

Abstract Advanced package technology often includes multi-chips in one package to accommodate the technology demand on size & functionality. Die tilting leads to poor device performance for all kinds of multi-chip packages such as chip by chip (CbC), chip on chip (CoC), and the package with both CbC and CoC. Traditional die tilting measured by optical microscopy and scanning electron microscopy has capability issue due to wave or electron beam blocking at area of interest by electronic components nearby. In this paper, the feasibility of using profilemeter to investigate die tilting in single and multi-chips is demonstrated. Our results validate that the profilemeter is the most profound metrology for die tilting analysis especially on multi-chip packages, and can achieve an accuracy of <2μm comparable to SEM.


1994 ◽  
Vol 42 (5) ◽  
pp. 681-686 ◽  
Author(s):  
V Rummelt ◽  
L M Gardner ◽  
R Folberg ◽  
S Beck ◽  
B Knosp ◽  
...  

The morphology of the microcirculation of uveal melanomas is a reliable market of tumor progression. Scanning electron microscopy of cast corrosion preparations can generate three-dimensional views of these vascular patterns, but this technique sacrifices the tumor parenchyma. Formalin-fixed wet tissue sections 100-150 microns thick from uveal melanomas were stained with the lectin Ulex europaeus agglutinin I (UEAI) and proliferating cell nuclear antigen (PCNA) to demonstrate simultaneously the tumor blood vessels and proliferating tumor cells. Indocarbocyanine (Cy3) was used as a fluorophore for UEAI and indodicarbocyanine (Cy5) was used for PCNA. Double labeled sections were examined with a laser scanning confocal microscope. Images of both stains were digitized at the same 5-microns intervals and each of the two images per interval was combined digitally to form one image. These combined images were visualized through voxel processing to study the relationship between melanoma cells expressing PCNA and various microcirculatory patterns. This technique produces images comparable to scanning electron microscopy of cast corrosion preparations while permitting simultaneous localization of melanoma cells expressing PCNA. The microcirculatory tree can be viewed from any perspective and the relationship between tumor cells and the tumor blood vessels can be studied concurrently in three dimensions. This technique is an alternative to cast corrosion preparations.


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