Engineering › Electrical and Electronic Engineering

Integrated Circuits and Semiconductor Failure Analysis

Works Count: 51222

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Description

This cluster of papers focuses on advanced techniques and methodologies for failure analysis of integrated circuits. It covers a wide range of topics including photon emission microscopy, laser voltage probing, backside analysis, nanoprobing, fault localization, time-resolved imaging, and electrical characterization. The papers explore innovative approaches to identify and analyze failures in CMOS circuits and other semiconductor devices.

Keywords

Failure Analysis; Integrated Circuits; Photon Emission Microscopy; Laser Voltage Probing; Backside Analysis; Nanoprobing; CMOS Circuits; Fault Localization; Time-Resolved Imaging; Electrical Characterization

High-resolution depth profiling in ultrathin Al2O3 films on Si

2000-01-10

E. P. Gusev , M. Copel , E. Cartier +3 more

A combination of two complementary depth profiling techniques with sub-nm depth resolution, nuclear resonance profiling and medium energy ion scattering, and cross-sectional high-resolution transmission electron microscopy were used to study … A combination of two complementary depth profiling techniques with sub-nm depth resolution, nuclear resonance profiling and medium energy ion scattering, and cross-sectional high-resolution transmission electron microscopy were used to study compositional and microstructural aspects of ultrathin (sub-10 nm) Al2O3 films on silicon. All three techniques demonstrate uniform continuous films of stoichiometric Al2O3 with abrupt interfaces. These film properties lead to the ability of making metal-oxide semiconductor devices with Al2O3 gate dielectric with equivalent electrical thickness in the sub-2 nm range.

The troponin complex and regulation of muscle contraction

1995-06-01

Chuck S. Farah , Fernando C. Reinach

In a wide variety of cellular settings, from organelle transport to muscle contraction, Ca2+ binding to members of the EF hand family of proteins controls the interaction between actin and … In a wide variety of cellular settings, from organelle transport to muscle contraction, Ca2+ binding to members of the EF hand family of proteins controls the interaction between actin and different myosins that are responsible for generating movement. In vertebrate skeletal and cardiac muscle the Ca2+ -binding protein troponin C (TnC) is one summit of the ternary troponin complex which, through its association with actin and tropomyosin on the thin filament, inhibits the actomyosin interaction at sub-micromolar Ca2+ concentrations and stimulates the interaction at micromolar Ca2+ concentrations. Because TnC does not interact directly with actin or tropomyosin, the Ca2+-binding signal must be transmitted to the thin filament via the other two troponin summits: troponin I (TnI), the inhibitory subunit, and troponin T (TnT), the tropomyosin-binding subunit. Thus, the troponin complex is a Ca2+ -sensitive molecular switch and the structures of and interactions between its components have been of great interest for many years. Although the crystal structure of TnC has been known for almost a decade, the molecular structures of TnI and TnT are not known and therefore convincing models of the organization of the troponin complex and the Ca2+-induced changes in its structure have not been forthcoming. Recent advances on a wide variety of fronts including 1) the bacterial expression and characterization of mutants of TnC, TnI, and TnT; 2) cross-linking and fluorescence studies; and 3) the determination of the crystal and nuclear magnetic resonance structures of synthetic and recombinant troponin fragments and complexes between EF hand proteins and their target peptides have provided new insights into the nature of the interactions between troponin subunits. This review discusses these recent advances with the aim of critically assessing molecular models of the nature of the Ca2+-induced structural transition in troponin.—Farah, C. S., Reinach, F. C. The troponin complex and regulation of muscle contraction. FASEB J. 9, 755-767 (1995)

Troponin

1968-10-01

Setsuro Ebashi , Ayako Kodama , FUMIKO EBASHI

1. A method for isolation of troponin from native tropomyosin was described. 2. Troponin in combination with tropomyosin restored the whole activity of native tropomyosin in sensitizing the interaction of … 1. A method for isolation of troponin from native tropomyosin was described. 2. Troponin in combination with tropomyosin restored the whole activity of native tropomyosin in sensitizing the interaction of myosin and actin to Ca ion. 3. Troponin was found to bind nearly 4 moles of Ca per 105 g, of which most were exchangeable. The result of the experiment to determine the binding constant of these Ca binding sites was explained by assuming that half of the binding sites possessed a binding constant of 1.3 × 106 M−1and the remaining half 5×104 M−1. 4. The amount of exchangeable Ca in the contractile system was mainly accounted for by the Ca-binding capacity of troponin, which was not influenced by other contractile proteins or ATP. 5. Cardiac troponin showed a much higher affinity for Sr ion than skeletal troponin. The ratio of the former affinity to the latter was in good agreement with the ratio of the sensitivity to Sr ion of a reconstituted contractile system containing cardiac troponin to that containing skeletal troponin. Based on these findings and the results described above, it was concluded that the sensitivity of a contractile system to Ca ion is solely dependent upon the affinity for Ca ion of the troponin molecule present. 6. The mechanism of troponin regulation of the interaction of actin and myosin was discussed.

Chemical Mapping of Semiconductor Interfaces at Near-Atomic Resolution

1989-02-20

A. Ourmazd , Derek W. Taylor , J. E. Cunningham +1 more

We combine chemical lattice imaging with digital pattern recognition to map, at near-atomic resolution, the compositional change across GaAs/AlGaAs interfaces of the highest optical quality. These maps quantify the information … We combine chemical lattice imaging with digital pattern recognition to map, at near-atomic resolution, the compositional change across GaAs/AlGaAs interfaces of the highest optical quality. These maps quantify the information content of each unit cell of the lattice image. Our results show that state-of-the-art GaAs/AlGaAs interfaces contain substantial atomic roughness on scales finer than suggested by optical measurements.

An overview of nitinol medical applications

1999-12-01

T.W. Duerig , Alan R. Pelton , D. Stöckel

Laser Conditions in Semiconductors

1961-01-01

Maurice Bernard , G. Duraffourg

Abstract The possibility of obtaining stimulated emissions in semiconductors has been considered for transitions between the conduction band and the valence band, or between one band and an impurity level. … Abstract The possibility of obtaining stimulated emissions in semiconductors has been considered for transitions between the conduction band and the valence band, or between one band and an impurity level. If the occupation of the bands and of the impurity levels is taken into account by quasi‐Fermi levels, the necessary condition for stimulated emission to be possible turns out to be simply: Δ F > hv where Δ F is the difference of the quasi‐Fermi levels of the initial and final state, and v is the emitted frequency. The existence of such quasi‐Fermi levels is discussed, and it is shown that the above condition is due to the second law of thermodynamics. Direct interband transitions in InAs or InSb, and transitions between the conduction band and Zn and In acceptor levels, respectively, in Ge and Si are thought to be sufficiently attractive to be studied experimentally.

Research Techniques in Nondestructive Testing

1984-06-01

R.S. Sharpe , J. D. Achenbach

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Probing ultrafast carrier and phonon dynamics in semiconductors

1998-02-15

Andreas Othonos

Over the past 2 decades there has been tremendous advancements in the field of ultrafast carrier dynamics in semiconductors. The driving force behind this movement other than the basic fundamental … Over the past 2 decades there has been tremendous advancements in the field of ultrafast carrier dynamics in semiconductors. The driving force behind this movement other than the basic fundamental interest is the direct application of semiconductor devices and the endless need for faster response and faster processing of information. To improve and develop microelectronics devices and address these needs, there must be a basic understanding of the various dynamical processes in the semiconductors which have to be studied in detail. Therefore, the excitation of semiconductors out of their equilibrium and the subsequent relaxation processes with various rates has become a key area of semiconductor research. With the development of lasers that can generate pulses as short as a few femtoseconds the excitation and subsequent probing of semiconductors on an ultrashort timescale have become routine. Processes such as carrier momentum randomization, carrier thermalization, and energy relaxation have been studied in detail using excite-and-probe novel techniques. This article reviews the status of ultrafast carrier and phonon dynamics in semiconductors. Experimental techniques such as excite-and-probe transmission, time-resolved up-conversion luminescence, and pump-probe Raman scattering along with some of the significant experimental findings from probing semiconductors are discussed. Finally, a selfconsistent theoretical model, which correlates the carrier and phonon dynamics in germanium on an ultrashort time scale, is described in detail.

Physical Versus Logical Fault Models MOS LSI Circuits: Impact on Their Testability

1980-06-01

Galiay , Crouzet , Vergniault

At the end of an IC production line, integrated circuits are generally submitted to three kinds of tests: 1) parametric tests to check electrical characteristics (voltage, current, power consumption), 2) … At the end of an IC production line, integrated circuits are generally submitted to three kinds of tests: 1) parametric tests to check electrical characteristics (voltage, current, power consumption), 2) dynamic tests to check response times under nominal operating conditions, and 3) functional tests to check its logical behavior.

Subpicosecond electrooptic sampling: Principles and applications

1986-01-01

J. A. Valdmanis , G. Mourou

This paper reviews the principles and applications of electrooptic sampling for the characterization of repetitive ultrafast electrical transients. Electrooptic sampling is an electric field sensitive technique that utilizes ultrashort optical … This paper reviews the principles and applications of electrooptic sampling for the characterization of repetitive ultrafast electrical transients. Electrooptic sampling is an electric field sensitive technique that utilizes ultrashort optical pulses as "sampling gates" via the Pockels effect in electrooptic media and has demonstrated subpicosecond temporal resolution and microvolt sensitivity. The technique can be adapted to characterize a wide variety of picosecond electronic devices such as field-effect transistors and photodetectors as well as probe complete integrated circuits with high temporal and spatial resolution.

Picosecond electro-optic sampling system

1982-08-01

J. A. Valdmanis , G. Mourou , C. W. Gabel

We report the construction of a sensitive electro-optic sampling system for the measurement of ultrafast electrical transients. This system has a temporal resolution of lessthan 4 ps (over 100- GHz … We report the construction of a sensitive electro-optic sampling system for the measurement of ultrafast electrical transients. This system has a temporal resolution of lessthan 4 ps (over 100- GHz bandwidth), better than 50-μV sensitivity and potential for a temporal resolution reaching the single picosecond. Demonstrated applications are ultrafast photodetector response characterization and time resolved photoconductivity.

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Trends and challenges in VLSI circuit reliability

2003-07-01

Cris S. Constantinescu

Deep-submicron technology is having a significant impact on permanent, intermittent, and transient classes of faults. This article discusses the main trends and challenges in circuit reliability, and explains evolving techniques … Deep-submicron technology is having a significant impact on permanent, intermittent, and transient classes of faults. This article discusses the main trends and challenges in circuit reliability, and explains evolving techniques for dealing with them.

Collection of Charge on Junction Nodes from Ion Tracks

1982-12-01

George C. Messenger

The collection of charge from ion tracks can produce logic upset and memory change in high density integrated circuits. It has been experimentally observed that drift conduction usually plays a … The collection of charge from ion tracks can produce logic upset and memory change in high density integrated circuits. It has been experimentally observed that drift conduction usually plays a dominant role when the ion track penetrates a junction. The first charge collection analysis concentrated on the diffusion conduction process. A recent analysis emphasizes drift conduction and describes the "funnel" which produces drift collection from the substrate. The funneling phenomenon has been modelled using two-dimensional computer simulations. It is extremely desirable to develop analytical solutions tp better understand the problem and to provide the basis for modelling the effect in circuit and system analysis computer codes such as SYSCAP. This paper develops an approximate analytic solution expressed as I(t) = Io [exp(-αt) - exp (-ßt)] (1) where Io is approximately the maximum current, 1/β is the collection time constant of the junction, and 1/ß is the time constant for initially establishing the ion track. The junction time constant is shown to be Kεo/qμND, and it increases slowly with funnel length when a funnel is present. The analysis shows that the excess carriers move almost exclusively by ambipolar diffusion for very early times, and that the fields present in semiconductor devices, including p-n junction fields, collapse. Ambipolar diffusion proceeds until the excess carrier concentration is reduced to approximately the background doping density at which time the junction field is restored and the carriers move by drift.

Noise in solid-state microstructures: A new perspective on individual defects, interface states and low-frequency (1/<i>ƒ</i>) noise

1989-01-01

M. J. Kirton , Michael J. Uren

Abstract In very small electronic devices the alternate capture and emission of carriers at an individual defect site generates discrete switching in the device resistance—referred to as a random telegraph … Abstract In very small electronic devices the alternate capture and emission of carriers at an individual defect site generates discrete switching in the device resistance—referred to as a random telegraph signal (RTS). The study of RTSs has provided a powerful means of investigating the capture and emission kinetics of single defects, has demonstrated the defect origins of low-frequency (1/ƒ) noise in these devices, and has provided new insight into the nature of defects at the Si/SiO2 interface.

Stress measurements in silicon devices through Raman spectroscopy: Bridging the gap between theory and experiment

1996-05-01

Ingrid De Wolf , H.E. Maes , Stephen Jones

The different steps that have to be taken in order to derive information about local mechanical stress in silicon using micro-Raman spectroscopy experiments, including theoretical and experimental aspects, are discussed. … The different steps that have to be taken in order to derive information about local mechanical stress in silicon using micro-Raman spectroscopy experiments, including theoretical and experimental aspects, are discussed. It is shown that the calculations are in general less complicated when they are done in the axes system of the sample. For that purpose, the secular equation is calculated in the axes system [110], [−110], [001], which is important for microelectronics structures. The theory relating Raman mode shift with stress tensor components is applied using two analytical stress models: uniaxial stress and planar stress. The results of these models are fitted to data from micro-Raman spectroscopy experiments on Si3N4/poly-Si lines on silicon substrate. In this fit procedure, the dimensions of the laser spot and its penetration depth in the substrate are also taken into account.

Picosecond photoconducting Hertzian dipoles

1984-08-01

D. H. Auston , K. P. Cheung , P. R. Smith

The generation transmission, and detection of extremely rapid electromagnetic pulses have been achieved using fast photoconducting materials as time-varying Hertzian dipoles. This approach, which has a measured time response of … The generation transmission, and detection of extremely rapid electromagnetic pulses have been achieved using fast photoconducting materials as time-varying Hertzian dipoles. This approach, which has a measured time response of 1.6 ps, overcomes many of the limitations imposed by transmission line structures, and due to its jitter-free behavior and open geometry is ideally suited for transient electromagnetic measurements of materials.

Integrated circuit yield statistics

1983-01-01

C.H. Stapper , F.M. Armstrong , K. Saji

The random failure statistics for the yield of mass-produced semiconductor integrated circuits are derived by considering defect and fault formation during the manufacturing process. This approach allows the development of … The random failure statistics for the yield of mass-produced semiconductor integrated circuits are derived by considering defect and fault formation during the manufacturing process. This approach allows the development of a yield theory that includes many models that have been used previously and also results in a practical control model for integrated circuit manufacturing. Some simpler formulations of yield theory that have been described in the literature are compared to the model. Application of the model to yield management are discussed and examples given.

Structural analysis of Si(111)-7×7 by UHV-transmission electron diffraction and microscopy

1985-05-01

K. Takayanagi , Y. Tanishiro , Masaetsu Takahashi +1 more

Structural analysis of the surface reconstructions investigated by ultrahigh vacuum (UHV) transmission electron microscopy (TEM) and diffraction (TED) is shown. By TED intensity analysis a new structural model of Si(111)-7×7 … Structural analysis of the surface reconstructions investigated by ultrahigh vacuum (UHV) transmission electron microscopy (TEM) and diffraction (TED) is shown. By TED intensity analysis a new structural model of Si(111)-7×7 is derived. The model basically consists of 12 adatoms arranged locally in the 2×2 structure, nine dimers on the sides of the triangular subunits of the 7×7 unit cell and a stacking fault layer. UHV–HREM of Si (111)-7×7 surface is commented.

Theory and application of electron channelling contrast imaging under controlled diffraction conditions

2014-05-24

Stefan Zaefferer , Nahid-Nora Elhami

Large-Signal Behavior of Junction Transistors

1954-12-01

J. Ebers , J.L. Moll

In the consideration of the junction transistor as a switch there are three characteristics of primary interest, the open impedance, the closed impedance, and the switching-time. A generalized two-terminal-pair theory … In the consideration of the junction transistor as a switch there are three characteristics of primary interest, the open impedance, the closed impedance, and the switching-time. A generalized two-terminal-pair theory of junction transistors is presented which is applicable, on a dc basis, in all regions of operation. Using this theory, the open and closed impedances of the transistor switch are expressible in terms of easily measurable transistor parameters. For the ideal transistor these parameters are the saturation currents of the emitter and collector junctions and the normal and inverted alphas. The transition of the transistor switch from open to closed, or vice versa, is discussed, including the effects of minority carrier storage. This transition can be expressed in analytic form in terms of the alphas and the normal and inverted alpha cut-off frequencies.

A method for location of the peaks in step-scan measured Bragg reflexions

1974-07-01

M. S. Lehmann , Finn Larsen

A method for location of the peak in a step-scan-measured Bragg reflexion profile is described. It leads to a ratio between the standard deviation of the intensity and the intensity, … A method for location of the peak in a step-scan-measured Bragg reflexion profile is described. It leads to a ratio between the standard deviation of the intensity and the intensity, σ(I)/I, which is near minimum. The method is based on the observation that if σ(I)/I is calculated for all possible peak widths for a given profile then σ(I)/I is minimum near the true value of the peak width, and minimal σ(I)/I can thus be used as a criterion for correct location of the peak. The intensity determined this way is however in general slightly underestimated, and the bias as well as possible corrections are discussed. In addition a simple function resembling σ(I)/I, which has proved to be useful for practical applications, is given.

Picosecond optical sampling of GaAs integrated circuits

1988-02-01

K. J. Weingarten , M.J.W. Rodwel , D. M. Bloom

Direct electrooptic sampling is a noncontact optical-probing technique for measuring with picosecond time resolution the voltage waveforms at internal nodes within GaAs integrated circuits. The factors contributing to system bandwidth, … Direct electrooptic sampling is a noncontact optical-probing technique for measuring with picosecond time resolution the voltage waveforms at internal nodes within GaAs integrated circuits. The factors contributing to system bandwidth, sensitivity, spatial resolution, and circuit perturbation are discussed, as are the circuit requirements for realistic testing of analog and digital devices. Measurements of high-speed GaAs integrated circuits are presented, including time-domain waveform and timing measurements of digital and analog circuits and frequency-domain transfer function measurements of microwave circuits and transmission structures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>

Low frequency noise in MOS transistors—I Theory

1968-09-01

S. Christensson , Ingemar Lundström , C. Svensson

Photon Emission from Avalanche Breakdown in Silicon

1956-04-15

A. G. Chynoweth , K. G. McKay

Visible light is emitted from reverse-biased silicon $p\ensuremath{-}n$ junctions at highly localized regions where avalanche breakdown is taking place. The emission occurs in both grown and diffused junctions. By using … Visible light is emitted from reverse-biased silicon $p\ensuremath{-}n$ junctions at highly localized regions where avalanche breakdown is taking place. The emission occurs in both grown and diffused junctions. By using junctions diffused to a depth of only 2 microns below the crystal surface, it was established that the light sources are randomly spaced over the whole area of the junction as well as around the periphery where the junction intercepts the surface. The light sources are too small to be resolved under a high-power microscope. Their sites are reproducible with current cycling and their intensity and color are relatively insensitive to the field distribution, to the junction width, and to temperature. The number of light spots increases with the current rather than individual spots growing brighter. It is concluded that all the breakdown current is carried through the junction by these localized light-emitting spots.The spectral distribution of the light is continuous with a long tail extending to photon energies greater than 3.3 ev. It is concluded that recombination between free electrons and free holes within the junction region is responsible for the light at the shorter wavelengths, the carrier energies in excess of the energy gap being supplied by the field. At longer wavelengths there appears to be a considerable contribution to the emission from intraband transitions.A tentative figure for the emission efficiency over the visible spectrum is one photon for every ${10}^{8}$ electrons crossing the junction. The recombination cross section required is reasonable, being about ${10}^{\ensuremath{-}22}$ ${\mathrm{cm}}^{2}$.

Metal-semiconductor Contacts

2005-12-19

E. H. Rhoderick

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Photoluminescence imaging of silicon wafers

2006-07-24

Thorsten Trupke , R.A. Bardos , Martin C. Schubert +1 more

Photoluminescence imaging is demonstrated to be an extremely fast spatially resolved characterization technique for large silicon wafers. The spatial variation of the effective minority carrier lifetime is measured without being … Photoluminescence imaging is demonstrated to be an extremely fast spatially resolved characterization technique for large silicon wafers. The spatial variation of the effective minority carrier lifetime is measured without being affected by minority carrier trapping or by excess carriers in space charge regions, effects that lead to experimental artifacts in other techniques. Photoluminescence imaging is contactless and can therefore be used for process monitoring before and after individual processing stages, for example, in photovoltaics research. Photoluminescence imaging is also demonstrated to be fast enough to be used as an in-line tool for spatially resolved characterization in an industrial environment.

A review of focused ion beam applications in microsystem technology

2001-07-01

Steve Reyntjens , Robert Puers

In this paper the possibilities of focused ion beam (FIB) applications in microsystem technology are reviewed. After an introduction to the technology and the operating principles of FIB, two classes … In this paper the possibilities of focused ion beam (FIB) applications in microsystem technology are reviewed. After an introduction to the technology and the operating principles of FIB, two classes of applications are described. First the subject of FIB for microsystem technology inspection, metrology and failure analysis is outlined. A procedure for cross sectioning on samples is presented, as well as some examples of how this technique can be applied to study processing results. The second part of the paper is on the use of FIB as a tool for maskless micromachining. Both subtractive (etching) and additive (deposition) techniques are discussed, as well as the combination of FIB implantation of silicon with subsequent wet etching. We will show the possibility to fabricate three-dimensional structures on a micrometre scale, and give examples of recent realizations thereof.

Inductive Fault Analysis of MOS Integrated Circuits

1985-01-01

John Paul Shen , W. Maly , Frances Ferguson

Inductive Fault Analysis (IFA) is a systematic Procedure to predict all the faults that are likely to occur in MOS integrated circuit or subcircuit The three major steps of the … Inductive Fault Analysis (IFA) is a systematic Procedure to predict all the faults that are likely to occur in MOS integrated circuit or subcircuit The three major steps of the IFA procedure are: (1) generation of Physical defects using statistical data from the fabrication process; (2) extraction of circuit-level faults caused by these defects; and (3) classification of faults types and ranking of faults based on their likelihood of occurrence Hence, given the layout of an IC, a fault model and a ranked fault list can be automatically generated which take into account the technology, layout, and process characteristics. The IFA procedure is illustrated by its applications to an example circuit. The results from this sample led to some very interesting observations regarding nonclassical faults.

Techniques for minimizing power dissipation in scan and combinational circuits during test application

1998-01-01

V. Dabholkar , S. Chakravarty , Irith Pomeranz +1 more

Reduction of power dissipation during test application is studied for scan designs and for combinational circuits tested using built-in self-test (BIST). The problems are shown to be intractable. Heuristics to … Reduction of power dissipation during test application is studied for scan designs and for combinational circuits tested using built-in self-test (BIST). The problems are shown to be intractable. Heuristics to solve these problems are discussed. We show that heuristics with good performance bounds can be derived for combinational circuits tested using BIST. Experimental results show that considerable reduction in power dissipation can be obtained using the proposed techniques.

Recent Developments in Nanofabrication Using Focused Ion Beams

2005-08-18

Ampere A. Tseng

Focused ion beam (FIB) technology has become increasingly popular in the fabrication of nanoscale structures. In this paper, the recent developments of the FIB technology are examined with emphasis on … Focused ion beam (FIB) technology has become increasingly popular in the fabrication of nanoscale structures. In this paper, the recent developments of the FIB technology are examined with emphasis on its ability to fabricate a wide variety of nanostructures. FIB-based nanofabrication involves four major approaches: milling, implantation, ion-induced deposition, and ion-assisted etching of materials; all these approaches are reviewed separately. Following an introduction of the uniqueness and strength of the technology, the ion source and systems used for FIB are presented. The principle and specific techniques underlying each of the four approaches are subsequently studied with emphasis on their abilities of writing structures with nanoscale accuracy. The differences and uniqueness among these techniques are also discussed. Finally, concluding remarks are provided where the strength and weakness of the techniques studied are summarized and the scopes for technological improvement and future research are recommended.

Noise as a diagnostic tool for quality and reliability of electronic devices

1994-01-01

L.K.J. Vandamme

Experimental facts about noise are presented which help us to understand the correlation between noise in a device and its reliability. The main advantages of noise measurements are that the … Experimental facts about noise are presented which help us to understand the correlation between noise in a device and its reliability. The main advantages of noise measurements are that the tests are less destructive, faster and more sensitive than DC measurements after accelerated life tests. The following topics are addressed: 1) the kind of noise spectra in view of reliability diagnostics such as thermal noise, shot noise, the typical poor-device indicators like burst noise and generation-recombination noise and the 1/f/sup 2/ and 1/f noise; 2) why conduction noise is a quality indicator; 3) the quality of electrical contacts and vias; 4) electromigration damage; 5) the reliability in diode type devices like solar cells, laser diodes, and bipolar transistors; and 6) the series resistance in modern short channel MESFET, MODFET, and MOST devices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>

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Micro-Raman spectroscopy to study local mechanical stress in silicon integrated circuits

1996-02-01

Ingrid De Wolf

Local mechanical stress is currently an important topic of concern in microelectronics processing. A technique that has become increasingly popular for local mechanical stress measurements is micro-Raman spectroscopy. In this … Local mechanical stress is currently an important topic of concern in microelectronics processing. A technique that has become increasingly popular for local mechanical stress measurements is micro-Raman spectroscopy. In this paper, the theoretical background of Raman spectroscopy, with special attention to its sensitivity for mechanical stress, is discussed, and practical information is given for the application of this technique to stress measurements in silicon integrated circuits. An overview is given of some important applications of the technique, illustrated with examples from the literature: the first studies of the influence of external stress on the Si Raman modes are reviewed; the application of this technique to measure stress in silicon-on-insulator films is discussed; results of measurements of local stress in isolation structures and trenches are reviewed; and the use of micro-Raman spectroscopy to obtain more information on stress in metals, by measuring the stress in the surrounding Si substrate is explained.

Skin Cancer Identification Using Multifrequency Electrical Impedance—A Potential Screening Tool

2004-11-22

Peter Åberg , Ingrid Nicander , Johan Hansson +3 more

Electrical bio-impedance can be used to assess skin cancers and other cutaneous lesions. The aim of this study was to distinguish skin cancer from benign nevi using multifrequency impedance spectra. … Electrical bio-impedance can be used to assess skin cancers and other cutaneous lesions. The aim of this study was to distinguish skin cancer from benign nevi using multifrequency impedance spectra. Electrical impedance spectra of about 100 skin cancers and 511 benign nevi were measured. Impedance of reference skin was measured ipsi-laterally to the lesions. The impedance relation between lesion and reference skin was used to distinguish the cancers from the nevi. It was found that it is possible to separate malignant melanoma from benign nevi with 75% specificity at 100% sensitivity, and to distinguish nonmelanoma skin cancer from benign nevi with 87% specificity at 100% sensitivity. The power of skin cancer detection using electrical impedance is as good as, or better than, conventional visual screening made by general practitioners.

Survey of low-power testing of VLSI circuits

2002-05-01

Patrick Girard

The author reviews low-power testing techniques for VLSI circuits. He prefaces this with a discussion of power consumption that gives reasons for and consequences of increased power during test. He … The author reviews low-power testing techniques for VLSI circuits. He prefaces this with a discussion of power consumption that gives reasons for and consequences of increased power during test. He ends with a discussion of the opportunity to use such techniques in varying situations.

Analysis of Single-Molecule FRET Trajectories Using Hidden Markov Modeling

2006-06-10

Sean McKinney , Chirlmin Joo , Taekjip Ha

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Improved troponin T ELISA specific for cardiac troponin T isoform: assay development and analytical and clinical validation

1997-03-01

Margit Müller-Bardorff , Klaus Hallermayer , Angelika Schröder +6 more

Abstract The first generation of troponin T ELISA (TnT 1) can yield false-positive results in patients with severe skeletal muscle injury. Therefore, a cardiac-specific second-generation troponin T ELISA (TnT 2) … Abstract The first generation of troponin T ELISA (TnT 1) can yield false-positive results in patients with severe skeletal muscle injury. Therefore, a cardiac-specific second-generation troponin T ELISA (TnT 2) was developed, in which the cross-reactive antibody 1B10 has been replaced by a high-affinity cardiac-specific antibody M11.7. No cross-reactivity of TnT 2 was observed with purified skeletal muscle troponin T (1000 μg/L) or in test samples from 43 marathon runners and 24 patients with rhabdomyolysis and highly increased creatine kinase. TnT 2 was increased &gt;0.2 μg/L in 5 of 40 patients with renal failure and in 4 of 20 muscular dystrophy patients. The detection limit is 0.012 μg/L. Day-to-day imprecision (CV) within the range 0.19–14.89 μg/L was &lt;5.8%. In 4955 patients without myocardial damage, 99.6% had TnT &lt;0.10 μg/L. Assay comparison (TnT 1 vs TnT 2) over the whole concentration range (i.e., in 323 samples from AMI-suspected patients) showed a slope, intercept, and standard error of estimate (Sey) of 1.18, 0.01 μg/L, and 0.81 μg/L, respectively.

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Metal-semiconductor surface barriers

1966-11-01

Carver Mead

Ion implantation in semiconductors—Part II: Damage production and annealing

1972-01-01

J. F. Gibbons

Radiation damage is produced in a crystalline target whenever a moving ion transfers sufficient energy to a target atom to displace it from its lattice site. For conditions of practical … Radiation damage is produced in a crystalline target whenever a moving ion transfers sufficient energy to a target atom to displace it from its lattice site. For conditions of practical importance in ion implantation, the radiation damage produced by the injected ions is severe, and the crystal must be carefully Annealed if the chemical effects of the implanted ions are to dominate the residual damage. The purpose of this paper is to review work that has been performed over the past several years in an effort to understand implantation-produced damage and its annealing characteristics, especially in silicon. The subject is developed as follows. A qualitative description of the damage produced by an implanted ion is presented in Section I, followed by a partial inventory of the basic defects that are found in ion-implanted silicon (Section II). The structure of individual damage clusters produced by both heavy and light ions is then described in Section III, where theoretical predictions are compared to a variety of experimental data. This is followed with a section on the depth distribution of defects and damage clusters (Section IV); and the paper is then concluded with a section on the annealing characteristics of implantation-produced damage (Section V). The development is organized to give primary emphasis to those facts and ideas that are essential for applications of ion implantation in the fabrication of MOS and junction devices in silicon. A future paper will review the state of the art in compound semiconductors.

MOS capacitance measurements for high-leakage thin dielectrics

1999-07-01

Kevin Yang , Chenming Hu

As oxide thickness is reduced below 2.5 nm in MOS devices, both series and shunt parasitic resistances become significant in capacitance-voltage (C-V) measurements. A new technique is presented which allows … As oxide thickness is reduced below 2.5 nm in MOS devices, both series and shunt parasitic resistances become significant in capacitance-voltage (C-V) measurements. A new technique is presented which allows the frequency-independent device capacitance to be accurately extracted from impedance measurements at two frequencies. This technique is demonstrated for a 1.7 nm SiO/sub 2/ capacitor.

RideNN: A New Rider Optimization Algorithm-Based Neural Network for Fault Diagnosis in Analog Circuits

2018-05-31

D. Binu , B. S. Kariyappa

Fault diagnosis in electronic circuits is an emerging area of research, where fully automated diagnosis systems are being developed for the investigation of the circuits. Developing test methods for the … Fault diagnosis in electronic circuits is an emerging area of research, where fully automated diagnosis systems are being developed for the investigation of the circuits. Developing test methods for the diagnosis of faults in analog circuits is still a complex task. Consequently, a technique for the fault diagnosis in analog circuits is designed by proposing a new optimization algorithm, named, rider optimization algorithm (ROA). The development of ROA is based on a group of riders, racing toward a target location. Moreover, a classifier, termed RideNN, is developed by including the proposed algorithm as the training algorithm for the neural network (NN). RideNN, along with the orthogonal transformation and Bhattacharyya coefficient, is applied for the fault diagnosis of analog circuits. The proposed technique is experimented using three basic circuits, such as triangular wave generator (TWG), low noise bipolar transistor amplifier (BTA), and differentiator (DIF) and an application circuit, solar power converter (SPC). The performance is evaluated using two evaluation metrics, namely, accuracy (ACC) and false alarm ratio (FAR). The analysis results show that the proposed technique attains an ACC of 99.9% in TWG, 99.9% in BTA, 99% in DIF, and 95% in SPC without noise.

Metrology for the next generation of semiconductor devices

2018-10-08

Ndubuisi G. Orji , Mustafa Badaroglu , Brian M. Barnes +7 more

Radiation damage to organic and inorganic specimens in the TEM

2019-01-21

R.F. Egerton

Measurement of the emitter saturation current by a contactless photoconductivity decay method.

1985-01-01

D.E. Kane , R.M. Swanson

Solder Joint Reliability

1991-01-01

Nanoleakage:Leakage Within the Hybrid Layer

1994-01-01

Hidehiko Sano

On the photoionization of deep impurity centers in semiconductors

1965-09-01

G. Lucovsky

Physical Aspects of Electron Microscopy and Microbeam Analysis

1976-04-01

Timothy K. Maugel , Benjamin M. Siegel , D. R. Beaman

Comparison of CT Imaging Methods for Defect Detection in a Multi-Material 7-Pin Power Connector

2025-06-24

Jochen Butzer , Thomas Riedel , C. Woelk +5 more | e-Journal of Nondestructive Testing

This paper explores industrial computed tomography (CT) for detection of anomalies such as voids and gaps in power connectors for automotive application. Such defects can lead to leakage paths which … This paper explores industrial computed tomography (CT) for detection of anomalies such as voids and gaps in power connectors for automotive application. Such defects can lead to leakage paths which can cause electrical malfunction or short circuits. A primary challenge in CT analysis arises from the proximity of dense metal parts next to plastic material, which induces strong imaging artifacts that hinder the evaluation of such defects. This study evaluates three imaging methods - standard Filtered Back Projection reconstruction (FBP), Quantum Reconstruction Technique (QRT), and dual-energy combination (DE) - to mitigate these artifacts and improve defect visualization. Each method's efficacy is assessed by analyzing the accuracy in detecting and characterizing gaps and voids. Results are compared to a target preparation and cross-section analysis with optical microscopy, providing a benchmark for reliability and accuracy. Full experimental findings and comparisons are detailed in the complete paper.

Signal integrity analysis in mixed CNT bundle interconnects using EM-RA

2025-06-21

Ashish Singh , Ajay Kumar , Amit Kumar | Journal of Computational Electronics

Improving Stem EBIC Specimen Quality with Argon Ion Beam Milling

2025-06-21

Cecile S. Bonifacio , William A. Hubbard , R. Li +2 more | Journal of Failure Analysis and Prevention

Physically constrained two-stage residual network for defect sizing using capacitive imaging technique

2025-06-21

Guojun Fan , Xiaokang Yin , Mingzhen Zhao +5 more | Mechanical Systems and Signal Processing

Quantum-enhanced electric field mapping within semiconductor devices

2025-06-20

NULL AUTHOR_ID | Physical Review Applied

Contact hole metrology study: understand the electron beam interaction with photoresist and how to minimize its impact

2025-06-18

Mohamed Zidan , Gian F. Lorusso , Danilo De Simone +6 more | Journal of Micro/Nanopatterning Materials and Metrology

Re-examination of important defect complexes in silicon: From microelectronics to quantum computing

2025-06-17

Petros-Panagis Filippatos , A. Chroneos , C. A. Londos | Journal of Applied Physics

The physical properties of silicon can be controlled by defects and impurities present in the lattice, with carbon, hydrogen, and oxygen being the most important impurities. During material processing, these … The physical properties of silicon can be controlled by defects and impurities present in the lattice, with carbon, hydrogen, and oxygen being the most important impurities. During material processing, these impurities interact with each other leading to the formation of clusters. The T-center contains two inequivalent C atoms with one of the two linked to an H interstitial atom. The I-center contains at least one C, one H, and one O atom in its structure. The M-center contains at least two C atoms and an H atom, but its exact structure has not been definitely determined. The G-center contains a C substitutional and C interstitial pair, whereas the W-center is composed of three silicon self-interstitials. Here, we re-examine the structure and the electronic properties of carbon–hydrogen and carbon–hydrogen–oxygen defects (T, M, I, G, and W-centers) as these are presently important for emerging quantum technologies. We discuss experimental work and how recent theoretical calculations have furthered our knowledge of these important centers.

GAN-Based Super-Resolution in Linear R-SAM Imaging for Enhanced Non-Destructive Semiconductor Measurement

2025-06-17

Thi Thu Ha Vu , Tan Hung Vo , T.N. Nguyen +7 more | Applied Sciences

The precise identification and non-destructive measurement of structural features and defects in semiconductor wafers are essential for ensuring process integrity and sustaining high yield in advanced manufacturing environments. Unlike conventional … The precise identification and non-destructive measurement of structural features and defects in semiconductor wafers are essential for ensuring process integrity and sustaining high yield in advanced manufacturing environments. Unlike conventional measurement techniques, scanning acoustic microscopy (SAM) is an advanced method that provides detailed visualizations of both surface and internal wafer structures. However, in practical industrial applications, the scanning time and image quality of SAM significantly impact its overall performance and utility. Prolonged scanning durations can lead to production bottlenecks, while suboptimal image quality can compromise the accuracy of defect detection. To address these challenges, this study proposes LinearTGAN, an improved generative adversarial network (GAN)-based model specifically designed to improve the resolution of linear acoustic wafer images acquired by the breakthrough rotary scanning acoustic microscopy (R-SAM) system. Empirical evaluations demonstrate that the proposed model significantly outperforms conventional GAN-based approaches, achieving a Peak Signal-to-Noise Ratio (PSNR) of 29.479 dB, a Structural Similarity Index Measure (SSIM) of 0.874, a Learned Perceptual Image Patch Similarity (LPIPS) of 0.095, and a Fréchet Inception Distance (FID) of 0.445. To assess the measurement aspect of LinearTGAN, a lightweight defect segmentation module was integrated and tested on annotated wafer datasets. The super-resolved images produced by LinearTGAN significantly enhanced segmentation accuracy and improved the sensitivity of microcrack detection. Furthermore, the deployment of LinearTGAN within the R-SAM system yielded a 92% improvement in scanning performance for 12-inch wafers while simultaneously enhancing image fidelity. The integration of super-resolution techniques into R-SAM significantly advances the precision, robustness, and efficiency of non-destructive measurements, highlighting their potential to have a transformative impact in semiconductor metrology and quality assurance.

Reflectometric Determination of Residual Oxides in Through-Silicon Vias for 3D Chip Integration - A Novel Approach

2025-06-17

Joachim Bauer , F. Heinrich , Francesco Villasmunta +7 more | Optics Express

A Novel 24 h × 7 Days Broken Wire Detection and Segmentation Framework Based on Dynamic Multi-Window Attention and Meta-Transfer Learning

2025-06-13

Han Wu , Shiyu Xiong , Yunhan Lin | Sensors

Detecting and segmenting damaged wires in substations is challenging due to varying lighting conditions and limited annotated data, which degrade model accuracy and robustness. In this paper, a novel 24 … Detecting and segmenting damaged wires in substations is challenging due to varying lighting conditions and limited annotated data, which degrade model accuracy and robustness. In this paper, a novel 24 h × 7 days broken wire detection and segmentation framework based on dynamic multi-window attention and meta-transfer learning is proposed, comprising a low-light image enhancement module, an improved detection and segmentation network with dynamic multi-scale window attention (DMWA) based on YOLOv11n, and a multi-stage meta-transfer learning strategy to support small-sample training while mitigating negative transfer. An RGB dataset of 3760 images is constructed, and performance is evaluated under six lighting conditions ranging from 10 to 200,000 lux. Experimental results demonstrate that the proposed framework markedly improves detection and segmentation performance, as well as robustness across varying lighting conditions.

Evolution of water layers on wafer surfaces during bond chamber evacuation

2025-06-12

Max Huber , Andreas Zienert , Jörg Schuster | Journal of Vacuum Science & Technology B Nanotechnology and Microelectronics Materials Processing Measurement and Phenomena

We present a model to predict the evolution of water layers on wafer surfaces in a bond chamber during isothermal evacuation. A previously published evaporation model is implemented in comsol … We present a model to predict the evolution of water layers on wafer surfaces in a bond chamber during isothermal evacuation. A previously published evaporation model is implemented in comsol multiphysics® and coupled to the gas flow emerging from decreasing total pressure at the chamber outlet, which simulates an attached vacuum pump. We show that a 2D (two-dimensional) axisymmetric model of the space between the wafers, when they are already aligned in the bond chamber, is sufficient to describe the evaporation and evacuation process. Hence, much computational cost and time can be saved compared to simulations, including a 3D geometry. The behavior of ultrathin water layers on SiO2 is described by disjoining pressure parameters extracted from measured equilibrium layer thicknesses provided by the literature. Depending on the relative humidity between the wafers, a decrease and buildup of the layer across the whole wafer takes place, respectively. Afterward, the water-air interface moves from the edge toward the center of the wafer as evacuation continues resulting in an equilibrium water layer evolving from the edge of the wafer toward its center.

A Particle-Based Field Ionization Algorithm in Quasi-Static PIC Codes

2025-06-12

Tang Rong , Weiming An , Jianzhao Wang +7 more | Plasma Physics and Controlled Fusion

Abstract Particle-in-cell simulation code, especially the quasi-static Particle-In-Cell code, has been an indispensable tool to the development of the plasma wake field accelerator. Such an advanced accelerator scheme uses a … Abstract Particle-in-cell simulation code, especially the quasi-static Particle-In-Cell code, has been an indispensable tool to the development of the plasma wake field accelerator. Such an advanced accelerator scheme uses a drive particle beam or a laser pulse to generate wake fields inside a plasma for accelerating another particle beam. The acceleration gradient can be 10 GeV/m or higher in the plasma wake field accelerator, which makes it a promising candidate as the main acceleration method in the future high energy electron-positron colliders or X-ray free electron laser facilities. In the plasma wake field acceleration, the plasma can be generated by ionizing the neutral gas with the Coulomb field around the particle beam or the electric field of the laser pulse. Therefore, the field ionization process plays a key role in the plasma wake field acceleration experiments. The 3D PIC code QuickPIC, which is based on the quasi-static approximation, has been widely used for efficiently modeling the plasma wake field accelerator problems including the field ionization process. However, the current field ionization algorithm in QuickPIC cannot simulate mobile ions. In this work, we developed a particle-based ionization method in order to track the motion of ions that generated during the ionization process. We also implement the new algorithm in another quasi-static PIC code QPAD, which additionally applied the azimuthal Fourier decomposition method compared with QuickPIC. The comparison of simulation results between the old and new algorithm and between QuickPIC and QPAD are presented. The comparison shows that for the plasma wake field acceleration simulation without the plasma ion motion, the particle-based method works as well as the old algorithm in both codes of QuickPIC and QPAD. When including the mobile ions in the field ionized plasma, QuickPIC and QPAD with the particle-based method show a well agreement with each other.

Parasitic RC estimation and defect prediction for embedded memory using machine learning

2025-06-12

Venkatesham Maddela , Sanjeet Kumar Sinha , M. Parvathi +1 more | Analog Integrated Circuits and Signal Processing

Momentum-resolved spectroscopic evidence of a metal-insulator transition in Si(111) <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msqrt><mml:mn>3</mml:mn></mml:msqrt><mml:mo>×</mml:mo><mml:msqrt><mml:mn>3</mml:mn></mml:msqrt></mml:mrow></mml:math> -Sn

2025-06-06

NULL AUTHOR_ID | Physical review. B./Physical review. B

Enhanced analog circuit fault diagnosis via continuous wavelet transform and dual-stream convolutional fusion

2025-06-05

Zhiwen Hou , Jiangtao Liu , Shoou-I Yu | Scientific Reports

PQ improvement with TLBO FOPID based SHAF

2025-06-04

Alok Kumar Mishra , Jeevan Jyoti Mahakud , Shekharesh Barik +3 more | CRC Press eBooks

Physical Correlation Between Stochasticity and Process-Induced Damage in Ferroelectric Memory Devices

2025-06-03

Ryun‐Han Koo , Seung Whan Kim , Jiseong Im +7 more | Research Square (Research Square)

<title>Abstract</title> This study investigates the influence of sputtering plasma-induced damage on stochastic characteristics in HfZrO₂ (HZO)-based ferroelectric tunnel junctions (FTJs), with an emphasis on memory and neuromorphic device optimization. Variation … <title>Abstract</title> This study investigates the influence of sputtering plasma-induced damage on stochastic characteristics in HfZrO₂ (HZO)-based ferroelectric tunnel junctions (FTJs), with an emphasis on memory and neuromorphic device optimization. Variation of the sputtering plasma power during top electrode deposition introduces distinct levels of trap within the HZO layer. Low-frequency noise (LFN) spectroscopy and temperature-dependent electrical measurements confirm that higher plasma power generates additional shallow-level traps, thereby promoting Poole-Frenkel conduction while simultaneously increasing current noise magnitude. Although the resulting enhancements in on-current density and ferroelectric tunnel electroresistance (TER) ratio are beneficial for high-density memory integration, these conditions also elevate stochastic fluctuations, potentially degrading read margins and long-term endurance. Furthermore, the observed increase in stochasticity negatively affects neuromorphic inference accuracy, particularly after endurance cycling stress. These results demonstrate the critical interplay among plasma process conditions, trap density, and LFN in FTJs. By systematically engineering sputtering process parameters, we optimize the electrical performance with minimized stochastic noise. This approach provides guidelines for the development of next-generation ferroelectric-based memories and neuromorphic systems with consideration of stochasticity, where robust performance and reliability are imperative for large-scale integration.

FPGA acceleration and IC mask optimization based on deep learning

2025-06-02

Yuzhang Liu | Journal of Computational Methods in Sciences and Engineering

Aiming at the low efficiency and accuracy of traditional methods in mask optimization of integrated circuits, a mask optimization algorithm based on deep learning is proposed. Firstly, an improved generation … Aiming at the low efficiency and accuracy of traditional methods in mask optimization of integrated circuits, a mask optimization algorithm based on deep learning is proposed. Firstly, an improved generation countermeasure network (GAN) model is designed. By introducing multi-scale feature fusion module and attention mechanism, the detail generation ability of mask pattern in lithography proximity effect correction is improved. Secondly, a dynamic weight adjustment strategy is proposed to adaptively balance the optimal weights in different regions during the training process. In the aspect of FPGA acceleration, a customized hardware architecture is designed for the computing bottleneck of the optimization algorithm. The experimental results show that, compared with the traditional OPC algorithm, this method significantly shortens the optimization time, improves the speedup ratio on the FPGA platform, and maintains a low edge placement error (EPE).

Statistical insights into time resolution of Resistive Plate Chambers

2025-06-01

M. Abbrescia | Journal of Instrumentation

Abstract The pursuit of the best possible time resolution remains one of the most critical areas of ongoing research on Resistive Plate Chambers (RPCs). Achieving top-tier time resolution is vital … Abstract The pursuit of the best possible time resolution remains one of the most critical areas of ongoing research on Resistive Plate Chambers (RPCs). Achieving top-tier time resolution is vital for numerous applications, ranging from high-energy physics experiments to medical imaging technologies. Various technological solutions are being proposed, each aiming to improve RPC performance, but their effectiveness must be validated through experimentation. Yet, in addition to technological progress, there are fundamental statistical factors inherent in the signal formation process within RPCs that impose theoretical limits on the time resolution that can be achieved. These limits arise from the random nature of particle interactions and signal generation in the chamber. A clear understanding of these statistical constraints is essential for setting realistic goals and guiding the development of new technologies. This paper will focus on these statistical limitations, providing an overview of how they affect RPC time resolution. We will examine the key factors contributing to these limits, as well as explore potential solutions and strategies to enhance time resolution within these statistical boundaries.

Micromanaging the Nuclear Lamina

2025-06-01

Alişya A. Anlaş | Biophysical Journal

The Hidden Dangers of Calcium Morphology During PCI

2025-06-01

Tieci Yi , Ching‐Lin Hsieh , J. K. Yeh | JACC Case Reports

The management of calcified coronary artery disease (CAD) during percutaneous coronary intervention (PCI) can lead to complications. A 72-year-old man had exertional dyspnea and severe calcified coronary artery disease (CAD) … The management of calcified coronary artery disease (CAD) during percutaneous coronary intervention (PCI) can lead to complications. A 72-year-old man had exertional dyspnea and severe calcified coronary artery disease (CAD) identified by means of coronary computed tomographic angiography (CTA). During PCI, a burr became entrapped in the mid left anterior descending artery (LAD) and was retrieved with the use of the push-and-pull technique. The procedure was further complicated by coronary perforation in the distal LAD during balloon angioplasty. Imaging review revealed eccentric calcification with a "nutcracker" appearance in the mid-LAD, indicating a risk for burr entrapment, and a "waning crescent" calcium nodule in the distal LAD, which warranted a higher risk of perforation. This case emphasizes the importance of early identification of high-risk calcium morphology with the use of imaging, including CTA and intravascular ultrasound to prevent procedural complications during PCI.

Broadband Nonlinear RAPID: a Baseline-free Probabilistic Imaging Approach for Single-Defect Localization using a Sparse Sensor Network

2025-06-01

Yusheng Ma , Saeid Hedayatrasa , Koen Van Den Abeele +1 more | NDT & E International

A unified system for high aspect ratio non-line-of-sight wet etching of silicon carbide via two-photon absorption

2025-06-01

Jared E. Payne , Hunter R. J. Stevenson , Gregory N. Nielson +1 more | Review of Scientific Instruments

This paper presents the technique and equipment that enable the creation of arbitrary high aspect ratio, non-line-of-sight 3D features in SiC. The technique is a combination of two-photon absorption and … This paper presents the technique and equipment that enable the creation of arbitrary high aspect ratio, non-line-of-sight 3D features in SiC. The technique is a combination of two-photon absorption and photo-electrochemical etching. SiC etches in hydrofluoric acid when holes are present. The holes are generated at an arbitrary location in the SiC substrate by using sub-bandgap light to transmit light through the substrate and then using two-photon absorption to produce holes at the focus of the laser. The basic equipment consists of an optical subsystem capable of producing high-intensity light at the focus, a motion control subsystem with accurate surface detection, and a fluid chamber that allows for incident light and etch solution to reach the etching surface. The technique and equipment are demonstrated by fabricating a non-line-of-sight through-wafer via completely through a SiC wafer.