Analysis of 2D and 3D defects associated with precipitation of Cu in silicon

1991 ◽  
Vol 49 ◽  
pp. 870-871
Author(s):  
P.M. Rice ◽  
MJ. Kim ◽  
R.W. Carpenter
Keyword(s):  
Colony Growth ◽  
Dark Field ◽  
Dark Side ◽  
Silicide Phase ◽  
Strain Fields ◽  
Near Surface ◽  
Unknown Composition ◽  
Secondary Precipitates ◽  
20 Nm ◽  
2D And 3D

Extrinsic gettering of Cu on near-surface dislocations in Si has been the topic of recent investigation. It was shown that the Cu precipitated hetergeneously on dislocations as Cu silicide along with voids, and also with a secondary planar precipitate of unknown composition. Here we report the results of investigations of the sense of the strain fields about the large (~100 nm) silicide precipitates, and further analysis of the small (~10-20 nm) planar precipitates.Numerous dark field images were analyzed in accordance with Ashby and Brown's criteria for determining the sense of the strain fields about precipitates. While the situation is complicated by the presence of dislocations and secondary precipitates, micrographs like those shown in Fig. 1(a) and 1(b) tend to show anomalously wide strain fields with the dark side on the side of negative g, indicating the strain fields about the silicide precipitates are vacancy in nature. This is in conflict with information reported on the η'' phase (the Cu silicide phase presumed to precipitate within the bulk) whose interstitial strain field is considered responsible for the interstitial Si atoms which cause the bounding dislocation to expand during star colony growth.

In Z-contrast, not all that glistens is high-Z

1995 ◽  
Vol 53 ◽  
pp. 174-175
Author(s):  
M. M. J. Treacy ◽  
M. E. Bisher ◽  
A. J. Jacobson ◽  
J. M. Gibson
Keyword(s):  
Local Strain ◽  
Dark Field ◽  
Specimen Preparation ◽  
Average Intensity ◽  
Hollow Cone ◽  
Strain Fields ◽  
Nanophase Materials ◽  
Specimen Orientation ◽  
20 Nm ◽  
Z Contrast

It is by now a given that high resolution Z-contrast is a useful imaging technique for detecting high atomic number (Z) domains in nanophase materials. However, image intensity also depends on specimen orientation, electron-optical geometry, thickness and local strain fields, as well as local structural ordering. In this paper we will present examples from our materials studies where contrasts from strain and short-range order in hollow-cone dark-field images provide important structural insights. Strain fields were found to be responsible for the unusual "blister' contrasts observed in hollow-cone dark field images of delaminated sheets of calcium sodium niobate layered materials. Wherever two sheets overlap, the average intensity increases and dark disks of diameter ~20 nm, with bright central spots, appear (Fig. 1). For large hollow-cone angles, q1 > 20 nm-1, the blisters vanish, although faint fine-scale features persist. Elasticity analysis and image simulations (Fig. 2) reveal that the blisters are pockets of gas or liquid that became trapped between sheets during the drying stage of the specimen preparation process, when individual sheets come into contact at random mutual angles and reseal (Fig. 3).

Extrinsic Gettering of Copper in Silicon: Heterogeneous Precipitation on Near-Surface Dislocations

1990 ◽  
Vol 209 ◽  
Author(s):  
P.M. Rice ◽  
M.J. Kim ◽  
R.W. Carpenter
Keyword(s):  
Point Defects ◽  
Precipitation Reaction ◽  
Strain Fields ◽  
Near Surface ◽  
Heterogeneous Precipitation ◽  
Planar Arrays ◽  
Unknown Composition

ABSTRACTCopper was precipitated on extrinsic near-surface dislocations in {100} Si wafers. Several types of precipitates were heterogeneously nucleated on low index planar arrays. Large crystalline precipitates with visible strain fields proved to bea silicide. Large weakly diffracting precipitates without strain fields proved to be voids. Small, thin, partially crystalline particles of unknown composition also precipitated on the arrays. Point defects played an important role in the precipitation reaction.

Characteristic Geometry and Diffraction Contrast of Dispersed ThO2 Crystals

1969 ◽  
Vol 27 ◽  
pp. 168-169
Author(s):  
R. J. Horylev ◽  
L. E. Murr
Keyword(s):  
Dark Field ◽  
Particle Orientation ◽  
Contrast Effects ◽  
Strain Fields ◽  
Diffraction Contrast ◽  
Dispersed Particles ◽  
Field Electron Microscopy ◽  
Dark Field Electron ◽  
Particle Images ◽  
Diffraction Effects

Smith has shown by dark-field electron microscopy of extracted ThO2 particles from TD-nickel (2% ThO2) that they possess single crystal characteristics. It is generally assumed that these particle dispersions are incoherent. However, some diffraction effects associated with the particle images appeared to be similar to coherency strain fields. The present work will demonstrate conclusively that ThO2 dispersed particles in TD-nickel (2% ThO2) and TD-NiCr (2% ThO2, 20% Cr, Ni) are single crystals. Moreover, the diffraction contrast effects are extinction fringes. That is, these effects arise because of the particle orientation with respect to the electron beam and the extinction conditions for various operating reflections The particles are in fact incoherent.

Effect of strain on ADF-STEM high-resolution images

1991 ◽  
Vol 49 ◽  
pp. 666-667
Author(s):  
M. Kelly ◽  
D.M. Bird
Keyword(s):  
High Resolution ◽  
Strong Influence ◽  
Intensity Variation ◽  
Dark Field ◽  
Atomic Resolution ◽  
Strain Fields ◽  
High Resolution Image ◽  
Annular Dark Field ◽  
High Resolution Images ◽  
Interesting Alternative

It is well known that strain fields can have a strong influence on the details of HREM images. This, for example, can cause problems in the analysis of edge-on interfaces between lattice mismatched materials. An interesting alternative to conventional HREM imaging has recently been advanced by Pennycook and co-workers where the intensity variation in the annular dark field (ADF) detector is monitored as a STEM probe is scanned across the specimen. It is believed that the observed atomic-resolution contrast is correlated with the intensity of the STEM probe at the atomic sites and the way in which this varies as the probe moves from cell to cell. As well as providing a directly interpretable high-resolution image, there are reasons for believing that ADF-STEM images may be less suseptible to strain than conventional HREM. This is because HREM images arise from the interference of several diffracted beams, each of which is governed by all the excited Bloch waves in the crystal.

scholarly journals CONTRIBUTION OF DEEP ELECTRICAL RESISTIVITY TOMOGRAPHY TECHNIQUE TO HYDROGEOLOGICAL STUDIES: CASES FROM AREAS IN KAVALA (NORTH GREECE)

2017 ◽  
Vol 43 (4) ◽  
pp. 1962
Author(s):  
G. Vargemezis ◽  
P. Tsourlos ◽  
I. Mertzanides
Keyword(s):  
Electrical Resistivity ◽  
Electrical Resistivity Tomography ◽  
Geological Structure ◽  
Resistivity Tomography ◽  
Near Surface ◽  
Resistivity Method ◽  
Area Of Interest ◽  
Vertical Electric Sounding ◽  
Hydrogeological Studies ◽  
2D And 3D

The most common geophysical method widely used in hydrogeological surveys concerning deep investigations (150-300m of depth) is the resistivity method and particularly the Vertical Electric Sounding (VES) using the Schlumberger array. VES interpretations assume 1D geoelectrical structure yet it is obvious that such an interpretation assumption is not valid in many cases where 2D and 3D geological features exist. In such cases the application of geoelectrical techniques which can provide both vertical and lateral information concerning the resistivity variations is required. Techniques such as the electrical resistivity tomography, mostly used for the 2D and 3D geoelectrical mapping of near surface applications can be adapted to be used for larger investigation depths provided that modified equipment (viz. cables) is used. In the present paper, the application of deep electrical resistivity tomography (ERT) techniques is applied. ERT array of 21 electrodes, at a distance of 50 meters between them (total length 1000 meters) has been used in several studied areas located in the prefecture of Kavala (North Greece). In several cases near surface structure has been compared with VLF data. The aim of the survey was to study in detail the geological-hydrogeological structure the area of interest in order to suggest the best location for the construction of hydrowells with the most promising results. The 2D images of the geological structure down to the depth of at least 200 meters allowed the better understanding of the behaviour of layered geological formations, since in several cases resistivity values have been calibrated with data from pre-existing boreholes.

Coupling Strategies Between Asymptotic and Numerical Models with Application to Ultrasonic Non-Destructive Testing of Surface Flaws

2019 ◽  
Vol 27 (02) ◽  
pp. 1850052
Author(s):  
Alexandre Imperiale ◽  
Nicolas Leymarie ◽  
Thibaud Fortuna ◽  
Edouard Demaldent
Keyword(s):  
Ultrasonic Testing ◽  
Hybrid Methods ◽  
Numerical Models ◽  
Destructive Testing ◽  
Near Surface ◽  
Industrial Sectors ◽  
Reciprocity Relations ◽  
Surface Flaws ◽  
Coupling Strategy ◽  
2D And 3D

Modeling for ultrasonic testing is an important tool in industrial sectors concerned with advanced inspection methods. A significant amount of effort has been directed to building hybrid methods, which try to encompass advantages of both asymptotic and numerical methods. In our work, we consider a hybrid coupling method based upon reciprocity relations. By deriving specific formulations for the incident and diffracted fields, we apply this strategy to the case of surface and near-surface flaws. We illustrate this coupling strategy in some canonical 2D and 3D ultrasonic testing configurations.

RapidNano: Towards 20nm Particle Detection on EUV Mask Blanks

MRS Advances ◽  
2016 ◽  
Vol 1 (31) ◽  
pp. 2225-2236 ◽  
Author(s):  
Jacques van der Donck ◽  
Peter Bussink ◽  
Erik Fritz ◽  
Peter van der Walle
Keyword(s):  
Particle Size ◽  
Signal To Noise Ratio ◽  
Semiconductor Industry ◽  
Optical Design ◽  
Dark Field ◽  
Detection Methods ◽  
Next Generation ◽  
Large Area ◽  
Dark Field Imaging ◽  
20 Nm

ABSTRACTCleanliness is a prerequisite for obtaining economically feasible yield levels in the semiconductor industry. For the next generation of lithographic equipment, EUV lithography, the size of yield-loss inducing particles for the masks will be smaller than 20 nm. Consequently, equipment for handling EUV masks should not add particles larger than 20 nm. Detection methods for 20 nm particles on large area surfaces are needed to qualify the equipment for cleanliness. Detection of 20 nm particles is extremely challenging, not only because of the particle size, but also because of the large surface area and limited available time.In 2002 TNO developed the RapidNano, a platform that is capable of detecting nanoparticles on flat substrates. Over the last decade, the smallest detectable particle size was decreased while the inspection rate was increased. This effort has led to a stable and affordable detection platform that is capable of inspecting the full surface of a mask blank.The core of RapidNano is a dark-field imaging technique. Every substrate type has a typical background characteristic, which strongly affects the size of the smallest detectable particle. The noise level is induced by the speckle generated by the surface roughness of the mask. The signal-to-noise ratio can be improved by illuminating the inspection area from nine different angles. This improvement was first shown on test bench level and then applied in the RapidNano3. The RapidNano3 is capable of detecting 42nm latex sphere equivalents (and larger) on silicon surfaces. RapidNano4, the next generation, will use 193 nm light and the same nine angle illumination mode. Camera sensitivity and available laser power determine the achievable throughput. Therefore, special care was given to the optical design, particularly the optical path. With RapidNano4, TNO will push the detection limit of defects on EUV blanks to below 20nm.

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