Line scan

Fig. 4.3 Left A-scan of the field variation above the test sample. Right Test sample with different sawcuts. Right below line scan at positions indicated by white arrows.

Fig. 5 Experimental setup (left) and result (right) of mean (line scan) refraction intensities of polystyrene and polystyrene blend (right).

Fig. 9.9. How single-crystal films are grown from polysilicon. The electron beam is line-scanned in a direction at right angles to the plane of the drawing.

There are three modes of analysis commonly used spectrum acquisition spatial distribution, or dot, mapping of the elements and elemental line scans. 

The results shown in Figure 6 above are an example of this mode of analysis, but include additional information on the chemical states of the Si. The third most frequently used mode of analysis is the Auger mapping mode, in which an Auger peak of a particular element is monitored while the primary electron beam is raster scanned over an area. This mode determines the spatial distribution, across the surface, of the element of interest, rather than in depth, as depth profiling does. Of course, the second and third modes can be combined to produce a three-dimensional spatial distribution of the element. The fourth operational mode is just a subset of the third mode a line scan of the primary beam is done across a region of interest, instead of rastering over an area. 

Figure 3 shows an optical profiler trace of the same portion of the wafer sample analyzed by the mechanical profiler. The resulting line scan in Figure 3a is similar to that for the mechanical system. The average and root-mean-square roughness are... 

Figure 3 Optical profiler measurements of a region on the unpolished back of a silicon wafer line scan (a) and 3D display (b) (Courtesy of WYCO Corp.).

Fig. 46. Schematic drawing of the failure surface of a lap joint prepared from hot-dipped galvanized steel substrates (top) and TOF-SIMS line scans showing the distribution of several mass numbers as a function of distance from the edge of the overlap (bottom). Reproduced by permission of John Wiley and Sons from Ref. [57].

Visually, failure was mostly eohesive within the adhesive (see Figs. 34 and 46). However, there was a small area of apparent interfacial failure ( initiation zone ) located at one end of each substrate. Line scans were eondueted aeross the initiation zone, from the edge of the substrate to the area of cohesive failure within the adhesive. From the line scans, it was apparent that there were patehes of polymer present in the initiation zone, even when failure appeared to be interfaeial (see Fig. 46). SIMS images of the initiation zone were constructed for various mass numbers (see Figs. 47-49). The images showed well-defined cation-rieh... 

Figure 12 AES spectra of the W-SiC composite sample, (a) Schematic diagram of the sample (the shaded regions represent the reaction zone), (b) C and O line-scan profiles. The maximum PE noise is indicated by an error bar. (From Ref. 74.)...

Fig. 7.88 Scanning electron micrographs of cross-sections through interaction layers with superimposed Fe and Zn K, line scans across the layers (

Figure 9. Phase reconstruction of image reported in Figure 6 using the reference of image reported in Figure 8. The phase map is shown in (a), which includes a laterally averaged line-scan of 15 pixels, (b) A surface map of the two particles shape is displayed. The surface plot has been heavily noise filtered through Gaussian smoothing to better display the particles shape.

Figure 8.6 STM image of Ni (11 l)-c(4 x 2) CO structure with (a) (4 x 2) (white) and c(4 x 2) (black) unit cells shown with corresponding corrugation line scan (0.2 A full scale) (b) similar to (a) under different tunnelling conditions and corresponding line scan (0.3 A full scale). (Reproduced from Ref. 20).

Figure 9.11 Thiophene adsorbed at 500 K on an H-atom pretreated MoS2 cluster (50 x 54 A2). Beam-like features at the metallic edge [scan line (i)] and the shifted intensity of the outermost edge protrusions relative to the clean edge (triangles refer to the clean edge). These shifts in intensity [line scan (ii)] are associated with changes in the local electronic structure after adsorption of thiophene observed with STM. All the images were taken at room temperature subsequent to thiophene adsorption at 500 K. (Reproduced from Ref. 34).

Line Scanning. In order to examine the variation of chemical composition within a sample, one approach is to select the X-ray signal from the element of interest and to display its intensity as the point of incidence of the electron beam is moved along a chosen path (by moving either the beam or the specimen). The instantaneous count rate is measured, and a trace of composition versus beam position is obtained, as illustrated in Figure 5.9. 

This EPMA line scan was analysed by wavelength dispersive spectroscopy, being part of a study by Horz and Kallfass of ornamental and ceremonial artifacts dated to approximately AD 50-300, recovered from the Royal Tombs of Sipan, Peru. 

It is possible to extend the line scanning method to two-dimensional scanning. In its simplest form, the display is made bright every time an X-ray photon is counted, thus generating a image of bright dots. The dot density provides a qualitative measure of the concentration of the element of interest. 

Zieba et al. (1997) also made measurements of the W concentration within individual qo lamellae, by making analysis line scans as close as possible to the reaction front (usually within 50-100 nm), Figure 5.23(A). The data shown in Figure 5.23(B) are the average of three line scans. 

Figure 5.23. (A) TEM micrograph of Co-32 wt%W alloy aged 5h at 975 K. (B) Line scan within sCo...

The Physical Electronics 680 Nanoprobe employs a field emission electron gun, and this results in a spatial resolution of less than lOnm. Ion bombardment for depth profiling is available in the SAM, and both the electron beam and the ion beam are computer controlled so that depth profiles can be run automatically, and maps and line scan of Auger electron distributions can be generated. 

Figure 5.36 shows a line scan obtained for these elements, as well as for oxygen, zinc and sulphur. 

Figure 5.36. SAM line scan across an intergranular corrosion trace in bronze belt of Figure 5.35. (Courtesy Dr Scott Lea, Pacific Northwest Laboratories.)...

Analysis by the Detection of X-rays or y rays. EPMA is a fully qualitative and quantitative method of non-destructive analysis of micrometre-sized volumes at the surface of materials, with sensitivity at the level of ppm. All elements from Be to U can be analysed, either in the form of point analysis, from line scans and also as X-ray distribution maps. Current software allows the combination of elemental data in the latter, so that, for example, the digital data for those elements that corresponds to a selected phase will produce an X-ray map of the distribution of that phase in a given microstructure. 

Figure 3. Calculated CBED rocking curves within the (000) disk. The calculations were made for a Si[l 10] zone axis, a primary beam energy of 193.35 keV and a crystal thickness of 1000 nm. The curves shown in the figure correspond to the line scan A-B of Figure 1.

Figure 9. Energy-filtered experimental and fitted Si[l 10] CBED rocking curves for (a) a line scan along the [111] direction and (b) a line scan along the [002] direction (see Figure 1). The calculations were made for a primary beam energy of 195.35keV and a crystal thickness of 369 nm.

Time-dependent analytical measurements, which give three-dimensional information of the type y = f(zy t) as shown schematically in Fig. 3.11a. The same characteristic holds for distribution analysis in one spatial direction, i.e., line scans, y = f(zylx). Such signal functions are frequently represented in form of multiple diagrams as shown in Fig. 3.11b. 

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