Subwavelength Defect Characterization Using Guided Wave Scattering Matrix

2013 ◽  
Vol 330 ◽  
pp. 504-509
Author(s):  
Yang Zheng ◽  
Jin Jie Zhou ◽  
Hui Zheng
Keyword(s):  
Wave Scattering ◽  
Scattering Matrix ◽  
Guided Wave ◽  
Defect Characterization ◽  
Challenging Problem ◽  
Recognition Method ◽  
Quantitative Characterization ◽  
S Matrix ◽  
Imaging Algorithms

Although many imaging algorithms such as ellipse and hyperbola algorithm can roughly locate defects in large plate-like structures with sparse guided wave arrays, quantitative characterization of them is still a challenging problem, especially for those small defects known as subwavelength defects. Scattering signals of defects contain abundant information so that can be used to evaluate defects. A defects recognition method using the S-matrix (scattering matrix) was presented. S-matrices of hole and crack with S0 mode incident were experimentally measured. The results show that defects can be recognized from the morphology of 2D S-matrix chart. This method has great potential to achieve more specific parameters of small defects with sparse guided wave arrays.

Oxygen and Carbon Defect Characterization In Silicon by Sims

1985 ◽  
Vol 59 ◽  
Author(s):  
R. S. Hockett ◽  
P. B. Fraundorf ◽  
D. A. Reed ◽  
D. H. Wayne ◽  
G. K. Fraundorf
Keyword(s):  
Computer Program ◽  
Image Enhancement ◽  
Thermal Processing ◽  
Precipitate Size ◽  
Defect Characterization ◽  
Interstitial Oxygen ◽  
Quantitative Characterization ◽  
Czochralski Silicon ◽  
Thermally Processed

ABSTRACTOxygen and carbon aggregation in silicon after thermal processing can be characterized using SIMS profiles and SIMS imaging. Fluctuations in the oxygen SIMS signal during the profile have been correlated with the change in interstitial oxygen after thermal processing as measured by FTIR and the precipitate size as measured by TEM. In cases where precipitation is known to be the cause of impurity clustering, a computer program for simulating the profiling process allows semi-quantitative characterization of precipitates as a function of depth. The use of a Resistive Anode Encoder on a CAMECA IMS-3f coupled with image enhancement can be used to image oxygen and carbon related defects. Examples of this technique are given by imaging oxygen aggregation and the co-aggregation of oxygen and carbon in thermally-processed Czochralski-silicon.

Guided wave scattering by geometrical change or damage: Application to characterization of fatigue crack and machined notch

Ultrasonics ◽  
2017 ◽  
Vol 73 ◽  
pp. 187-195 ◽  
Author(s):  
Nicolas Quaegebeur ◽  
Nidhal Bouslama ◽  
Maxime Bilodeau ◽  
Robin Guitel ◽  
Patrice Masson ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Wave Scattering ◽  
Guided Wave ◽  
Geometrical Change

Sensors Distribution Strategies in Guided Wave Sparse Arrays Based on Defects Scattering Properties

2013 ◽  
Vol 330 ◽  
pp. 510-516
Author(s):  
Bin Wu ◽  
Ye Chi Zhang ◽  
Yang Zheng ◽  
Cun Fu He
Keyword(s):  
Circular Hole ◽  
Guided Wave ◽  
Fe Model ◽  
Imaging Methods ◽  
Sparse Arrays ◽  
Sensor Arrangement ◽  
Piezoelectric Elements ◽  
Imaging Algorithms ◽  
Through Hole

Most of imaging algorithms used in guided wave arrays share the same assumption that the signal scattered from defects will propagate uniformly in all directions. However, some recent researches on scattering properties of guided wave in defects demonstrate that the scattered signal is un-uniform even for a circular hole. Scattering properties of defects were studied and effects of sensors distribution strategies were presented in this paper. A 3D FE model was employed to study the sensor arrangement method and two basic imaging methods ellipse and hyperbola algorithm was used. Experiment was implemented in a 3mm aluminum plate with piezoelectric elements. Results show that for crack-like defects and through-hole, both ellipse and hyperbola imaging algorithms were valid. The number and position of transducers affect the accuracy of crack imaging. To detecting different kinds of defect the preferable array arrangement should be set according to the scattering characterization of defect.

Solution of the Single-Site Aspherical Scattering Problem for the Dirac Equation

1991 ◽  
Vol 253 ◽  
Author(s):  
Stephen C. Lovatt ◽  
B.L. Gyorffy ◽  
Guang-Yu Guo
Keyword(s):  
Dirac Equation ◽  
Partial Wave ◽  
Wave Scattering ◽  
Crystalline Silicon ◽  
Scattering Problem ◽  
Scattering Matrix ◽  
Single Site ◽  
Finite Range ◽  
S Matrix

ABSTRACTWe study the scattering solutions of the Dirac equation numerically for anisotropic, finite range (warped muffin-tin), potentials. In particular, we calculate the partial-wave scattering matrix, ƒAA'(ε) and S-matrix SAA′(ε), for a potential characteristic of crystalline Silicon. We illustrate the consequences of aspherical scattering with reference to Silicon.

Local strain and defects in silicon wafers due to nanoindentation revealed by full-field X-ray microdiffraction imaging

2015 ◽  
Vol 22 (4) ◽  
pp. 1083-1090 ◽  
Author(s):  
Z. J. Li ◽  
A. N. Danilewsky ◽  
L. Helfen ◽  
P. Mikulik ◽  
D. Haenschke ◽  
...  
Keyword(s):  
Local Strain ◽  
Strain Engineering ◽  
Silicon Wafers ◽  
Defect Characterization ◽  
Quantitative Characterization ◽  
Strain Fields ◽  
Full Field ◽  
X Ray ◽  
Quantitative Mapping

Quantitative characterization of local strain in silicon wafers is critical in view of issues such as wafer handling during manufacturing and strain engineering. In this work, full-field X-ray microdiffraction imaging using synchrotron radiation is employed to investigate the long-range distribution of strain fields in silicon wafers induced by indents under different conditions in order to simulate wafer fabrication damage. The technique provides a detailed quantitative mapping of strain and defect characterization at the micrometer spatial resolution and holds some advantages over conventional methods.

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