Strain Measurements and Laue Diffraction with Microbeams

1994 ◽  
Vol 375 ◽  
Author(s):  
P.-C. Wang ◽  
G. S. Cargill ◽  
I. C. Noyan

AbstractWe describe a system being developed to use x-rays for spatially resolved measurements of strain, microstructure and composition in thin films. These capabilities are particularly important for improved understanding of electromigration, stress relaxation, and associated reliability issues in microelectronics. The system uses white radiation collimated and focused with a tapered glass capillary, an area CCD detector for measuring Laue patterns, and an energy sensitive Si detector for measuring lattice spacings. Examples are shown of strain measurements for a 4 μm thick Al film on a Si substrate with 300 μm and 30 μm x-ray beams; of Laue diffraction from a single grain for a 40 μm thick Al foil with a 0.3 μm x-ray beam; and of x-ray fluorescence mapping for a patterned Cu film with a 30 μm x-ray beam.

Author(s):  
D. A. Carpenter ◽  
M. A. Taylor

The development of intense sources of x rays has led to renewed interest in the use of microbeams of x rays in x-ray fluorescence analysis. Sparks pointed out that the use of x rays as a probe offered the advantages of high sensitivity, low detection limits, low beam damage, and large penetration depths with minimal specimen preparation or perturbation. In addition, the option of air operation provided special advantages for examination of hydrated systems or for nondestructive microanalysis of large specimens.The disadvantages of synchrotron sources prompted the development of laboratory-based instrumentation with various schemes to maximize the beam flux while maintaining small point-to-point resolution. Nichols and Ryon developed a microprobe using a rotating anode source and a modified microdiffractometer. Cross and Wherry showed that by close-coupling the x-ray source, specimen, and detector, good intensities could be obtained for beam sizes between 30 and 100μm. More importantly, both groups combined specimen scanning with modern imaging techniques for rapid element mapping.


2012 ◽  
Vol 472-475 ◽  
pp. 1451-1454
Author(s):  
Xue Hui Wang ◽  
Wu Tang ◽  
Ji Jun Yang

The porous Cu film was deposited on soft PVDF substrate by magnetron sputtering at different sputtering pressure. The microstructure and electrical properties of Cu films were investigated as a function of sputtering pressure by X-ray diffraction XRD and Hall effect method. The results show that the surface morphology of Cu film is porous, and the XRD revealed that there are Cu diffraction peaks with highly textured having a Cu-(220) or a mixture of Cu-(111) and Cu-(220) at sputtering pressure 0.5 Pa. The electrical properties are also severely influenced by sputtering pressure, the resistivity of the porous Cu film is much larger than that fabricated on Si substrate. Furthermore, the resistivity increases simultaneously with the increasing of Cu film surface aperture, but the resistivity of Cu film still decreases with the increasing grain size. It can be concluded that the crystal structure is still the most important factor for the porous Cu film resistivity.


1988 ◽  
Vol 32 ◽  
pp. 115-120 ◽  
Author(s):  
D. A. Carpenter ◽  
M. A. Taylor ◽  
C. E. Holcombe

A laboratory-based X-ray microprobe, composed of a high-brilliance microfocus X-ray tube, coupled with a small glass capillary, has been developed for materials applications. Because of total external reflectance of X rays from the smooth inside bore of the glass capillary, the microprobe has a high sensitivity as well as a high spatial resolution. The use of X rays to excite elemental fluorescence offers the advantages of good peak-to-background, the ability to operate in air, and minimal specimen preparation. In addition, the development of laboratory-based instrumentation has been of Interest recently because of greater accessibility when compared with synchrotron X-ray microprobes.


1995 ◽  
Vol 403 ◽  
Author(s):  
P.-C. Wang ◽  
G. S. Cargill ◽  
I. C. Noyan ◽  
E. G. Liniger

AbstractWe describe spatially resolved grain orientation mapping of polycrystalline films using a synchrotron-based x-ray microdiffraction system. The system consists of a tapered glass capillary as a white x-ray concentrator, an energy-dispersive solid state detector and an x-y-z sample stage. Two mapping modes are discussed: reciprocal-space mapping and real-space mapping. Information about the orientations of grains within the irradiated volume is determined by reciprocal-space mapping. The locations of grains having a specified orientation are determined by real-space mapping. Examples are shown for blanket films of AI(4 wt.% Cu) 4μm-thick and 0.5μm thick. Results are also shown for 10μm-wide and μm-wide pure lines. X-ray beams of 10inm diameter were used for these measurements. Spatially resolved thermal strain measurements were made for a single 10μm-wide, 200μm-long passivated Al line, and they were found to be consistent with calculations based on equi-biaxial thermal stress within the line.


2008 ◽  
Vol 93 (7) ◽  
pp. 071904 ◽  
Author(s):  
H. Bei ◽  
R. I. Barabash ◽  
G. E. Ice ◽  
W. Liu ◽  
J. Tischler ◽  
...  

Author(s):  
A. G. Nassiopoulos ◽  
E. Valamontes ◽  
T. Travlos ◽  
C. Tsamis

The total enhancement factor in X-ray Microanalysis of thin overlayers has been measured at different primary beam energies by comparing the signal from a thin film deposited on a bulk material to that from a thin unsupported film of the same composition. This enhancement factor contains the contribution of both backscattered electrons and characteristic and bremsstrahlung X-rays created in the bulk by the primary beam , which ionize the film in their way out of the sample.The experimental results from a Cu film on different substrates ( Si, Ni and Au ) are compared to Monte-Carlo calculations, performed by the authors. In these calculations [1,2] all three correction factors cited above (backscattering, characteristic and continuous X-rays from the bulk) are taken into account. It is thus demonstated that the contribution of continuous X-rays from the bulk take important values (as high as 12-14%) in cases where the substrate is of a high Z material at high primary beam energies (40 keV).


Author(s):  
D. X. Balaic ◽  
Z. Barnea ◽  
K. A. Nugent ◽  
R. F. Garrett ◽  
J. N. Varghese ◽  
...  

Tapered glass capillaries for X-ray beam concentration have been a topic of much interest for the synchrotron X-ray community in recent years. These optics have long held the promise of high-intensity microbeam generation for the “hard” X-ray energies used in crystallography and fluorescence analysis.X-ray concentration is achieved by exploiting the total external reflection property of glass surfaces for glancing angles of incidence. X-rays directed into the entrance aperture of the capillary are reflected toward an exit aperture of smaller dimensions, resulting in an increased X-ray flux per unit area at the exit aperture. Capillary designs with a true geometrical focus beyond the capillary exit are also possible.Our group has recently demonstrated a paraboloidally-tapered glass capillary optic which produced a focused X-ray beam using a monochromatised synchrotron source. The optic was designed to produce a focal region for singly-reflected X-rays at a point 40 mm from the end of the capillary. Such a focal region was observed, with a FWHM intensity gain of two orders of magnitude over the incident X-ray intensity from the channel-cut monochromator. Moreover, this gain was achieved for X-ray energies from 5 to 20 keV. We subsequently used a similar optic to obtain X-ray diffraction patterns from a crystal of hen egg-white lysozyme on image plates. The use of the capillary-focused beam yielded diffraction patterns 70 to 100 times faster than using an unfocused beam from the channel-cut monochromator alone. Placement of the crystal at different positions in the capillary-focused beam demonstrated the focusing of Bragg reflections and diffraction from a small volume of crystal.


2021 ◽  
Vol 54 (2) ◽  
pp. 588-596
Author(s):  
Andrey A. Lomov ◽  
Vasily I. Punegov ◽  
Boris M. Seredin

Si(111) wafers patterned with an array of vertical 100 µm-wide Al-doped (1 × 1019 cm−3) p-channels extending through the whole wafer were studied by X-ray Laue diffraction techniques. The X-ray techniques included projection topography, and measurement of rocking curves and cross sections in the vicinity of the 02\overline 2 reciprocal space node in the double- and triple-crystal geometry, respectively. The channels are uniform along the depth of the wafer, and their structural perfection is comparable to that of the silicon matrix between the channels. Simulation of the rocking curves was performed using the methods of the dynamical theory of X-ray diffraction. The rocking-curve calculations both taking into account and neglecting the effect of the instrumental function were carried out using the Takagi–Taupin equations. The calculated angular dependences of intensities of both diffracted and transmitted X-rays correspond well to the experimentally obtained rocking curves and demonstrate their high sensitivity to the structural distortions in the channel. An unambiguous reconstruction of strain and structural distortions in the Si(Al) channel using the Laue diffraction data requires further development of the theoretical model.


1997 ◽  
Vol 473 ◽  
Author(s):  
P.-C. Wang ◽  
G. S. Cargill ◽  
I. C. Noyan ◽  
E. G. Liniger ◽  
C.-K. Hu ◽  
...  

ABSTRACTX-ray microdiffraction was applied to study the thermal and electromigration strains in 10 μm-wide Al conductor lines with 10 μm spatial resolution. X-rays were collimated either by pinholes or by tapered glass capillaries to form x-ray microbeams. Measurements were made in a symmetric-reflection geometry so that the strains normal to the sample surface could be examined at different positions along the conductor lines. Results of thermal strain measurements show that the SiO2 passivation plays an important role in limiting relaxation of in-plane compressive thermal stresses in the Al lines, but that the passivation is not effective in confining the overall thermal expansion of the Al line along the film normal. Electromigration strain measurements show that a linear stress gradient developed within the first hour of electromigration. The magnitude of the stress gradient changed little until fast stress relaxations occurred near the anode end of the line. Possible mechanisms are discussed in light of these observations.


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