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The additive manufacturing (AM) of α + β titanium alloys using electron beam (EB) and laser directed energy deposition (DED) processes has been widely characterized in both the as-deposited and post processed conditions. Fine basket weave α lath structures are commonly observed in both the as-deposited and post processed hot isostatically pressed (HIP) conditions for both laser and EB DED processes, but more in-depth knowledge of the crystallographic texturing and variant selection of the α laths growing from the primary β-grains across the height of EB DED Ti-6Al-4V structures is not well established. At locations near the substrate in both conditions, microtexturing is weak, but EB DED builds exhibit a strong microtexture and pronounced variant selection with increasing build height. On the other hand, the laser DED builds displayed weak texturing and no prominent variant selection across all heights. With the addition of HIP post processing, there was no change in microtexturing of the coarsened α laths for both the laser and EB structures, and the same variant selection observed in the as-deposited EB DED builds was present. [ABSTRACT FROM AUTHOR]

Abstract Polyimide films are widely used in space with extreme environments, where high energy beam irradiation and corresponding coupling treatment could occur. The combined effect of high energy electrons (1.2 MeV) and high tensile stress (50 MPa) on the degradation behavior of polyimide films was studied by means of scanning electron microscopy, atomic force microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and mechanical testing. The degradation of polyimide films was evaluated by analyzing the microstructure and mechanical properties. The results indicated that the external tensile stress and irradiation coupling treatment resulted in the breakage of a larger number of chemical bonds and greater deterioration of the surface quality when compared with the irradiated polyimide samples. After irradiation-load coupling treatment, numerous micro-cracks were formed on the polyimide surface, facilitating the diffusion of oxygen into polyimide films and thus increasing the probability of free radical reactions. Moreover, the coupling treatment led to a more significant decrease in tensile strength and elongation of polyimide films by 10% and 35%, respectively. The mechanism of molecular chains' scission and crosslinking as well as correlations between molecular chains and mechanical performances were discussed. The obtained results indicated that the external tensile stress accelerates the degradation process during electron beam irradiation; thus, the tensile stress potentially seriously deteriorates polyimide film properties in irradiated environments. Highlights • The effects of irradiation-load coupling treatment on polyimide films are investigated by the self-design platform. • The surface roughness and defects increase significantly under irradiation-load coupling treatment. • C≡N bonds will form on polyimide films after the irradiation-load coupling treatment. • Tensile stress could induce the disorder of polyimide films from semi-crystalline into amorphous state. [ABSTRACT FROM AUTHOR]

The effect of thermal aging on the charging phenomena in cross-linked polyethylene (XLPE) has been studied under electron beam irradiation in scanning electron microscope (SEM). The dynamic variation of trapped charge represents the trapping process of XLPE under electron beam irradiation. We have found that the trapped charge variation can be approximated by a first order exponential function. The amount of trapped charge presents enhanced values at the beginning of aging at lower temperatures (80 °C and 100 °C). This suggests the diffusion of cross-linking by-products to the surface of sample that acts as traps for injected electrons. The oxidation which is a very important form of XLPE degradation has an effect at the advanced stage of the aging process. For higher temperatures (120 °C and 140 °C), the taken part process in the evolution of the trapped charge is the crystallinity increase at the beginning of aging leading to the trapped charge decreasing, and the polar groups generated by thermo-oxidation process at the end of aging leading to the trapped charge increase. Variations of leakage current according to the aging time have quite similar trends with the dielectric losses factor and consequently some correlations must be made between charging mechanisms and the electrical behaviour of XLPE under thermal aging. [ABSTRACT FROM AUTHOR]

Superconducting titanium thin films are good candidates for transition edge sensors. In this paper, we deposit titanium thin films on cooled silicon-on-insulator substrates by using electron-beam evaporation. The deposition rate dependence of the film stress, resistivity, and superconducting transition temperature are presented and analyzed. The relationship between film electrical properties and thickness is discussed. For investigating the heating influence on thin Ti films, a depth profile of oxygen diffusion in the films is also analyzed by X-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, a new strategy which blends low-density polyethylene (LDPE), magnesium hydroxide (MH) and lauryl acrylate by electron-beam radiation for production of LDPE-based composites with high performance was proposed. It was found that, MH played main roles in flame retardancy but reduced processing flow and mechanical properties of the composites. Meanwhile, melt flow rate (MFR) increased while viscosity of the composites decreased with lauryl acrylate content increased, facilitating LDPE composites processing. Electron beam radiation could prompt crosslinking of lauryl acrylate, which significantly enhanced the mechanical properties of LDPE composites. Meanwhile, lauryl acrylate addition only slightly decreased the flame retardancy, suggesting that LDPE composites could remain high flame retardancy even when lauryl acrylate content was high. The study highly demonstrated the feasibility to produce LDPE-based composites simultaneously with high flame retardancy and high mechanical properties by the blending strategy provided in this study. [ABSTRACT FROM AUTHOR]

In this study, the efficacy of electron beam irradiation versus chemical coupling for yielding polyethersulfone (PES) membranes with antibacterial properties was investigated. For the surface coating, a recently discovered lead compound, IL-KKA, comprising a short peptide sequence functionalized with imidazolium groups, was used. For better integration within the membrane, several novel variants of IL-KKA were generated. Membrane immobilization was achieved using different doses of electron beam irradiation and NHS/EDC chemical coupling. Physicochemical characterization of the coated membranes was performed by water contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy. Our results show that electron beam irradiation is as effective and gentle as chemical coupling using the NHS/EDC method. Moreover, it was demonstrated that the obtained membranes exhibit promising antibacterial activity against B. subtilis. In summary, the technique presented herein might be promising as a template for developing future anti-biofilm devices. [ABSTRACT FROM AUTHOR]

High-resolution imaging of electron beam–sensitive materials is one of the most difficult applications of transmission electron microscopy (TEM). The challenges are manifold, including the acquisition of images with extremely low beam doses, the time-constrained search for crystal zone axes, the precise image alignment, and the accurate determination of the defocus value. We develop a suite of methods to fulfill these requirements and acquire atomic-resolution TEM images of several metal organic frameworks that are generally recognized as highly sensitive to electron beams. The high image resolution allows us to identify individual metal atomic columns, various types of surface termination, and benzene rings in the organic linkers. We also apply our methods to other electron beam–sensitive materials, including the organic-inorganic hybrid perovskite CH3NH3PbBr3. [ABSTRACT FROM AUTHOR]

Protection of the molten pool from gaseous contamination has always been of prime importance in welding of titanium alloys. A vacuum environment in electron beam welding serves this purpose and eliminates the use of shielding gas during the joining process. However, this may lead to variation in microstructure, mechanical properties, residual stress distribution and distortions compared to the widely used laser and TIG welding operations. In the present work, EBW was used to weld Ti-5Al-2.5Sn alloy sheet with welding current ranging from 14 mA to 20 mA. Owing to vacuum environment, oxygen contents in the fusion zone were very low for all the welding currents. However, welding current had a significant influence on the weld pool width, micro-hardness and grain size in the FZ. A complete martensitic transformation was not observed in the FZ at any of the welding currents used. Furthermore, maximum residual stresses upto 280 MPa (compressive) and 320 MPa (tensile) were found in the longitudinal direction near the weld centerline. The measured high residual stresses, distortions and partial martensitic transformations in FZ were attributed to a reduced cooling rate due to the absence of shielding gas in electron beam welding. [ABSTRACT FROM AUTHOR]

This paper reports the effect of electron beam irradiation on CuO thin films synthesized by the successive ionic layer adsorption and reaction (SILAR) method on copper foil for supercapacitor and biocompatibility application. Pristine and irradiated samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and electrochemical study. Pristine and irradiated CuO films were pure monoclinic phase, with uniform nanostructures over the whole copper foil. After irradiation, CuO samples had formed innovative nanostructures. Biocompatibility of pristine and irradiated CuO samples suggest that CuO sample is non-toxic and ecofriendly. The specific capacitance of pristine and irradiated CuO strongly depends on surface morphology, and CuO electrodes after irradiation showed superior performance than pristine CuO. The highest specific capacitance of the 20 kGy irradiated CuO nanoflowers exceeded 511 F g −1 at 10 mV s −1 in 1 M KOH electrolyte. Irradiated CuO samples also showed lower ESR, and were superior to other report electrical energy storage materials. [ABSTRACT FROM AUTHOR]

The limiting parameters of an intense sub-millisecond electron beam generated in the source with a plasma cathode on the basis of a low-pressure multi-arc discharge with mesh stabilization of the cathode (emission) plasma boundary and mobile anode (beam) plasma boundary are investigated. It is demonstrated that the limiting parameters of the electron beam in the examined electrode system are limited by its energy content on a level of about 4 kJ the excess of which leads to an electric breakdown of the accelerating gap. The optimal pressures are determined at which the beam during its transportation in the longitudinal magnetic field with a preset configuration has maximal parameters for the given electrode system. Different mechanisms of electric breakdown initiation and methods for increasing the electric strength of the high-voltage accelerating gap in this electrode system are discussed. [ABSTRACT FROM AUTHOR]

We show that, in the Regge limit, beam asymmetries in η and η ′ photoproduction are sensitive to hidden strangeness components. Under reasonable assumptions about the couplings we estimate the contribution of the ϕ Regge pole, which is expected to be the dominant hidden strangeness contribution. The ratio of the asymmetries in η ′ and η production is estimated to be close to unity in the forward region 0 < − t / GeV 2 ≤ 1 at the photon energy E lab = 9 GeV , relevant for the upcoming measurements at Jefferson Lab. [ABSTRACT FROM AUTHOR]

The high heat flux test facility HELCZA (High Energy Load CZech Assembly) is in the commissioning phase in which the full range of operational parameters of the facility are being validated. HELCZA is designed for cyclic heat loading for testing ITER plasma-facing components with heat flux densities in the range of several MW/m 2 . The heat flux is ensured by an 800 kW electron beam gun emitting electrons at 55 kV acceleration voltage. The main parameters to be validated concern not only the maximum power of the electron beam but also the entire cooling system which enables to vary the inlet cooling water temperature in a range from room temperature up to 320 °C and water pressure up to 15 MPa. The design flow rate is adjustable up to 40 m 3 /h over the entire temperature and pressure range. The sample movement is ensured by three types of sample holders for: a) First Wall panels, b) divertor inner vertical target and c) antenna faraday screens as well as other test mock-ups and small-scale samples. All the above mentioned system parameters are currently being tested with the objective of a full validation of HELCZA facility during its commissioning phase, which is currently proceeding. The first part of the commissioning phase results are shown and described in detail. [ABSTRACT FROM AUTHOR]

The ITER first wall panels are exposed directly to thermonuclear plasma and must extract heat loads of approximately 2 MW/m 2 (normal heat flux) to 4.7 MW/m 2 (enhanced heat flux). The panels are qualified through high heat flux cyclic testing before installation in ITER. Initially, the first wall panel prototypes will undergo full-power tests, they will be followed by the pre-series panels and finally the series ones. The experimental complex HELCZA (High Energy Load CZech Assembly) has been completed and is currently in the commissioning phase. HELCZA shall be optimised to provide a cyclic heating of the ITER EU first wall panels with a heat flux in the multi-MW/m 2 range using an 800 kW electron beam. On a reduced area it is possible to reach GW/m 2 scale. Total available test area in HELCZA is 4 m 2 depending on the experimental setup. Operational conditions of the HELCZA facility enable the temperature of the cooling water to be set between 25 °C and 320 °C, within a pressure range up to 15 MPa. The cooling system provides an optimal flow rate up to 40 m 3 /h independent of the pressure. [ABSTRACT FROM AUTHOR]

Since the average power of a 0.42 THz s harmonic gyrotron with complex cavity is small, the laser calorimeter AC2500H is adopted to measure the pulsed output power. However, the optimal spectral response of AC2500H is far from the operating frequency of the designed gyrotron. Thus the reflection on the laser calorimeter would be large, which would affect the mode competition in the designed gyrotron. In this paper, the influence of reflections from the laser calorimeter and output window is investigated by a multi-mode, time-dependent nonlinear code. From numerical simulation results, it is shown that the output power of the designed gyrotron is greatly decreased by the reflection from AC2500H although it doesn't cause excitations of competing modes. And it is found that when the reflection phase on the output window θ r , n , 1 is 5 π / 11 , reflection magnitude on the laser calorimeter Γ r , n , 2 is 0.44 and the corresponding phase θ r , n , 2 is 3 π / 7 , the variation of the calculated output power is very similar with the experimental result. Moreover, if the beam quality and Ohmic loss in the cavity wall are both considered, the calculated power can fit perfectly with the measured one. [ABSTRACT FROM AUTHOR]

The evolution of residual stress and microstructure has been investigated in electron-beam welded Ti-6Al-4V alloy rings in order to develop an understanding of how the distribution of through-thickness residual stress correlates with microstructural evolution. A multiple technique approach to residual stress measurement was employed using a combination of different measurement techniques including X-ray diffraction (XRD), hole drilling method based on electronic speckle pattern interferometry (ESPI), and the contour method. It was found that there is a strong correlation between the change in residual stress and alpha phase morphology across the weld. The fusion zone exhibited highly tensile residual stress which was typified by an entirely acicular α′ microstructure formed by a displacive transformation within prior β grains on cooling. The tensile residual stress in the centre of the weld reduced towards the heat affected zone, transitioning to a compressive residual stress upon increasing distance from the weld centre. The transition from tensile to compressive residual stress correlates with a significant decrease in the volume fraction of α′ and an increase in the bimodal morphology of equiaxed primary alpha in a diffusional transformed beta matrix leading to elongated alpha in the base material. [ABSTRACT FROM AUTHOR]

The FERMI free-electron laser (FEL) of Elettra Sincrotrone Trieste, Italy, is a user facility driven by a 1.5 GeV 10–50 Hz S-band radiofrequency linear accelerator (linac), and it is based on an external laser seeding scheme that allows lasing at the shortest fundamental wavelength of 4 nm. An increase of the beam energy to 1.8 GeV at a tolerable breakdown rate, and an improvement of the final beam quality is desired in order to allow either lasing at 4 nm with a higher flux, or lasing at shorter wavelengths. This article presents the impedance analysis of newly designed S-band accelerating structures, for replacement of the existing backward travelling wave structures (BTWS) in the last portion of the FERMI linac. The new structure design promises higher accelerating gradient and lower impedance than those of the existing BTWS. Particle tracking simulations show that, with the linac upgrade, the beam relative energy spread, its linear and nonlinear z-correlation internal to the bunch, and the beam transverse emittances can be made smaller than the ones in the present configuration, with expected advantage to the FEL performance. The repercussion of the upgrade on the linac quadrupole magnets setting, for a pre-determined electron beam optics, is also considered. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO)-based polymers containing long PEO chains are one of the best materials for postcombustion processes, attending to their separation properties. Optimal conditions for the application of the membrane separation module are immediately after elimination of water vapor, NO x , SO2, and dust particles, where the temperature of the gas is between 25 and 40 °C. Materials with high contents and longer length of PEO are the ideal candidates for the application in terms of properties. Unfortunately, these materials are normally not applicable due to, at these temperatures, the high crystallinity of PEO chains, which leads to poor gas separation properties. Here, by electron beam irradiation, it has been possible to eliminate or substantially reduce the crystallinity of poly(ether-imide)s with high PEO content, which is confirmed by the positive effect in the separation properties. Optimal dosage to eliminate the crystallinity and to maximize permeability has been investigated. [ABSTRACT FROM AUTHOR]

The thermal annealing induced physical properties of electron beam vacuum evaporated CdZnTe thin films have been investigated in the present work. The films of thickness 300 nm were deposited on indium tin oxide coated glass substrates followed by thermal annealing at 100 °C, 200 °C and 300 °C. The pristine and annealed films were subjected to the X-ray diffraction, UV–Vis spectrophotometer, Fourier transform infrared (FTIR) spectroscopy, source meter and Energy-dispersive spectroscopy for structural, optical, electrical and elemental composition analysis respectively. The structural analysis revealed that the films have cubic oriented polycrystalline structure with preferred orientation (111). The optical absorbance is found to increase with annealing while optical energy band gap is observed to decrease. Different optical constants like absorption coefficient, refractive index, dielectric constants and energy loss functions have been calculated using Herve-Vandamme model, dielectric theory, Swanepoel model and discussed. The FTIR study indicates the absorption intensity is increased with annealing temperature. The elemental analysis revealed to the presence of Cd, Zn and Te elements in the deposited films. The current-voltage tests show that the electrical conductivity is increased with thermal annealing. The results revealed to a demanding behavior of annealed films for the solar cell applications. [ABSTRACT FROM AUTHOR]

This paper investigates the physical properties of 99.91% pure copper produced by Additive Manufacturing via selective electron beam melting (SEBM). Eddy current measurements and laser flash analyses are used to determine the electrical and the thermal conductivity. Electrical and thermal conductivity follow the Wiedemann-Franz law. The correlation of conductivities and porosity shows that 99.95 % dense components with nearly optimal conductivities (σ55.82 MS m-1 and λ=400.1Wm-1 K-1) can be fabricated with SEBM. The small deviation from the theoretical maximum of copper (59.7 MS m-1) can be explained by the characteristics of the raw material and chemical impurities. [ABSTRACT FROM AUTHOR]

The detection of 200–1000 MeV neutrons requires large amounts, ~ 100 cm , of detector material because of the long nuclear interaction length of these particles. In the example of the NeuLAND neutron time-of-flight detector at FAIR, this is accomplished by using 3000 monolithic scintillator bars of 270 × 5 × 5 cm 3 size made of a fast plastic. Each bar is read out on the two long ends, and the needed time resolution of σ t < 150 ps is reached with fast timing photomultipliers. In the present work, it is investigated whether silicon photomultiplier (SiPM) photosensors can be used instead. Experiments with a picosecond laser system were conducted to determine the timing response of the assembly made up of SiPM and preamplifier. The response of the full system including also the scintillator was studied using 30 MeV single electrons provided by the ELBE superconducting electron linac. The ELBE data were matched by a simple Monte Carlo simulation, and they were found to obey an inverse-square-root scaling law. In the electron beam tests, a time resolution of σ t = 136 ps was reached with a pure SiPM readout, well within the design parameters for NeuLAND. [ABSTRACT FROM AUTHOR]

Dissimilar joining of mild steel and Fe-7% Al alloy was carried out using electron beam welding (EBW) process under three different weld operating conditions such as with beam oscillations, without beam oscillations and at higher welding speeds. Laboratory based X-ray computed tomography (XCT) was used for three dimensional (3D) visualisation of porosity under various welding conditions. Quantitative analysis of porosity such as the average size and number of pores were evaluated from XCT results as a function of beam oscillation and welding speed. XCT results show that the application of beam oscillation results in decrease in average size of the pores as well as a decrease in number of pores in the welded joints. Further, it was observed that an increase in weld speed results in an increase in porosity in the weld joint. Raman spectroscopy analysis shows the presence of hydrogen gas which could be responsible for porosity formation in EBW dissimilar joints. This study shows that the application of beam oscillation improves the weld quality by decreasing the porosity in the weld joints. [ABSTRACT FROM AUTHOR]

The article focuses on the experimental study of exclusive neutral-pion electroproduction measured by applying 5.75-gigaelectronvolt electron beam with the help of the particle physics detector CEBAF Large Acceptance Spectrometer (CLAS). Topics include role of parton's orbital angular momenta in total spin of the nucleon, information on high-energy hadron collisions, study of inelastic scattering to analyse generalized parton distributions (GPDs) of longitudinal momentum and polarization.

A silicon nanowire field-effect transistor (SiNW FET) with local side-gates and Pd surface decoration is demonstrated for hydrogen (H2) detection. The SiNW FETs are fabricated by top-down method and functionalized with palladium nanoparticles (PdNPs) through electron beam evaporation for H2 detection. The drain current of the PdNP-decorated device reversibly responds to H2 at different concentrations. The local side-gates allow individual addressing of each sensor and enhance the sensitivity by adjusting the working region to the subthreshold regime. A control experiment using a non-functionalized device verifies that the hydrogen-sensitivity is originated from the PdNPs functionalized on the SiNW surface. [ABSTRACT FROM AUTHOR]

New sub-GeV gauge forces ("dark photons") that kinetically mix with the photon provide a promising scenario for MeV-GeV dark matter and are the subject of a program of searches at fixed-target and collider facilities around the world. In such models, dark photons produced in collisions may decay invisibly into dark-matter states, thereby evading current searches. We reexamine results of the SLAC mQ electron beam dump experiment designed to search for millicharged particles and find that it was strongly sensitive to any secondary beam of dark matter produced by electron-nucleus collisions in the target. The constraints are competitive for dark photon masses in the ~1-30 MeV range, covering part of the parameter space that can reconcile the apparent (g-2)μ anomaly. Simple adjustments to the original SLAC search for millicharges may extend sensitivity to cover a sizable portion of the remaining (g-2)μ anomaly-motivated region. The mQ sensitivity is therefore complementary to ongoing searches for visible decays of dark photons. Compared to existing direct-detection searches, mQ sensitivity to electron-dark-matter scattering cross sections is more than an order of magnitude better for a significant range of masses and couplings in simple models. [ABSTRACT FROM AUTHOR]

The present paper reports the influence of hot work (isothermal deformation accompanied with heat treatment) on microstructure and properties of electron beam welded dissimilar joint. Ti2AlNb alloy and TC11 alloy were used to fabricate the joints. Isothermal deformation and heat treatment were performed under certain conditions. The structures were analysed using optical microscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results show that the as welded metal of Ti2AlNb/TC11 joint is mainly composed of α2 and β phases. The metastable β phase transformed into α+β phases during deformation and heat treatment processes. There are no big differences in tensile strength of joints under different conditions. However, the impact toughness of the weld has improved 72% after hot work. [ABSTRACT FROM AUTHOR]

Electron-beam testing technique includes photoemissive probing; electrooptic sampling; charge density probing and photoexcitation are analyzed. Among these techniques an ideal contactless probing system is simple, inexpensive to operate and compatible with the existing test equipment. It will not perturb the circuit and would measure electric signals with minimum crosstalk. Experimental results demonstrate that multiple optical test vectors can be input on the periphery of a DUT (device under test) with negligible crosstalk using this technique. The bandwidth of the test system would be compatible with picosecond data pulses and it would not be limited to certain materials. The approach offers increased testability and measurement of the "chip under test". [ABSTRACT FROM PUBLISHER]

A novel nondestructive failure analysis technique to rapidly locate tiny voids in narrow metallization line covered with passivation is proposed, based on the simulation results. In this technique, the current alteration in a metal line under study is recorded continuously when it is subjected to electron beam scanning and biased by a small external voltage. Finite-element analysis is performed to simulate the temperature distribution and current alteration in the metal line. The electron-beam heating is demonstrated as the most important factor contributing to the current alteration. Reconstruction of voids with any shape (such as wedge or slit) is possible on the basis of the gradient of the current alteration. It is found that the minimum detectable void size can be as low as 50 nm. Experimental verification of the technique is underway. [ABSTRACT FROM PUBLISHER]

Electron-beam testing (EBT) is currently used at two stages in the development and manufacture of integrated circuits (ICs), namely for chip verification and failure analysis. These are explained with the aid of two examples. EBT is, however, only one of many diagnostic tools. In order to classify it more usefully, a scenario is described that takes account of trends in chip development and packaging, and the linking of EBT with CAD (computer-aided design) and CAT (computer-aided testing). The conclusion is reached that EBT will remain an indispensable diagnostic tool. In future, it will probably be used under increasingly more difficult conditions, however, due primarily to the greater complexity of specimen preparation and test stimuli generation. [ABSTRACT FROM AUTHOR]

A hierarchical VLSI fault tracing method is proposed which isapplicable to the case where only CAD layout data is available in theCAD-linked electron beam test system. The CAD layout data is assumedto be hierarchically structured. The method uses the expansion of apreviously proposed integrated algorithm which combines atransistor-level fault tracing algorithm and a successive circuitextraction from a non-hierarchically or a flat structured CAD layoutdata. The method allows us to trace a fault hierarchically from thetop level cell to the lowest primitive cell and from the primitivecell to the transistor-level circuit in a consistent mannerindependent of circuit functions even when the cell data and thetransistor-level circuit data exist in a level as a mixture. Anapplication of the method to a hierarchically structured CMOS modellayout with about 600 transistors shows its validity. [ABSTRACT FROM AUTHOR]

In order to display the voltage contrast images of integrated circuits (ICs) in the stroboscopic scanning electron microscope in pseudo-color, a point is to extract the voltage changes as precisely as possible from the noisy stroboscopic images. To achieve this, we propose a method in which all sampled voltage information data on each equipotential electrode in ICs are averaged. The method is composed of three stages: 1) extraction of electrode configuration pattern in ICs; 2) averaging all voltage contrast data on the equipotential electrode; 3) assignment of the color on the electrode according to the averaged data of voltage changes. Application to an IC is presented to demonstrate the effectiveness of the method. [ABSTRACT FROM PUBLISHER]

A fully computer-controlled scanning electron microscope (SEM) system is described. The system, which has feedback control loops for probe current and contrast of the secondary electron detector, allows program control of SEM electron optical parameters such as accelerating voltage, probe current, and beam diameter. As an example of program control, electron micrographs which demonstrate high controllability of the system are shown when the accelerating voltage is changed from 1 kV to 10 kV with the probe current maintained constant at 10 pA. [ABSTRACT FROM PUBLISHER]