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Deposition of ZnS thin films by electron beam evaporation technique, effect of thickness on the crystallographic and optical properties
摘要: Deposition of Zinc sulfide (ZnS) thin films on Si (100) and glass substrates has been performed using electron beam evaporation (EBE) method without annealing. Film structure has been analyzed by XRD, while SEM and AFM have been used to explore the films morphology. Raman spectroscopy has been used to confirm film composition. The stoichiometry has been verified by EDX and XPS techniques. XRD patterns indicated that the films possess a polycrystalline cubic structure with orientations along (111) and (220) planes. The crystallinity has been better with film thickness in the 350–1700 nm range while the RMS roughness increases. Optical properties of the grown films were characterized by optical transmittance measurements (UV–Vis). The deduced energy band gap of the films shows a clear reduction from 3.45 eV to 3.36 eV with increasing film thickness. The evolution of refractive index, extinction coefficient, and dielectric constants with thickness has been investigated from transmittance spectra in the 500–1000 nm wavelength range.
关键词: ZnS,optical characteristics,Thin films,electron beam evaporation
更新于2025-09-23 15:22:29
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A Fuzzy Inference System for Unsupervised Deblurring of Motion Blur in Electron Beam Calibration
摘要: This paper presents a novel method of restoring the electron beam (EB) measurements that are degraded by linear motion blur. This is based on a fuzzy inference system (FIS) and Wiener inverse filter, together providing autonomy, reliability, flexibility, and real-time execution. This system is capable of restoring highly degraded signals without requiring the exact knowledge of EB probe size. The FIS is formed of three inputs, eight fuzzy rules, and one output. The FIS is responsible for monitoring the restoration results, grading their validity, and choosing the one that yields to a better grade. These grades are produced autonomously by analyzing results of a Wiener inverse filter. To benchmark the performance of the system, ground truth signals obtained using an 18 μm wire probe were compared with the restorations. Main aims are therefore: (a) Provide unsupervised deblurring for device independent EB measurement; (b) improve the reliability of the process; and (c) apply deblurring without knowing the probe size. These further facilitate the deployment and manufacturing of EB probes as well as facilitate accurate and probe-independent EB characterization. This paper’s findings also makes restoration of previously collected EB measurements easier where the probe sizes are not known nor recorded.
关键词: electron beam calibration,signal and image processing,fuzzy inference system,fuzzy deblurring,linear motion blur,fuzzy logics
更新于2025-09-23 15:22:29
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Apply DFT Integrated Enhanced EBAC Methodology on Defect Isolations
摘要: Design for test (DFT) has been widely applied to digital circuit failure analysis (FA) in semiconductor industries. The FA methods based on DFT involve layer-by-layer checks using a polisher and an SEM for defect identification and localization. Yet these methods have limitations with high risks of sample damages. Besides, they are highly dependent on the technical proficiencies of operators and, thus, they are not effective for precise defect isolations. This problem has been aggravated, especially at advanced nodes. The nano-probing electron beam absorbed current (EBAC) has significant advantages on precisely locating defects. This technique is to directly identify specific defects without layer-by-layer checks. Therefore, it can minimize sample damages during sample pretreatment. EBAC is an efficient technique to isolate the defects when the circuit is at the floating condition. Because the ground lines exist almost everywhere in a chip and they are for, e.g., electronic static discharge charge releases or connecting with sources for pickup, EBAC becomes a natural option for us. However, due to poor EBAC images, EBAC’s applications are restricted when the circuits under test have grounding paths. In this paper, we propose two enhanced EBAC analysis methods, based on the DFT and EBAC integrated system, for the defect isolations with grounded connections. It is the first time the DFT and EBAC integrated system is reported, and we successfully demonstrated EBAC applicability by real FA cases.
关键词: Design for test (DFT),Grounding line,Fault isolation,Electron beam absorbed current (EBAC),Failure analysis (FA)
更新于2025-09-23 15:21:21
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Liquid Phase Studies of Nanomaterials
摘要: Liquid cell transmission electron microscopy (LCTEM) is a relatively new technique enabling researchers to study dynamic phenomena in materials sciences, life sciences and electrochemistry. LCTEM has proved to be a remarkable tool for observing colloidal nanoparticle syntheses at fairly high temporal and spatial resolutions offered by transmission electron microscopy (TEM). Though the idea of observing syntheses in their native media is not new, a practical approach has only been made possible through massive improvements in microfabrication technology to fabricate liquid cells.[1] The idea is to use thin window materials such as SiN membranes (50 nm or less) to encapsulate tens of cubic nanometers of liquid in a stable thin profile suitable forTEM imaging considering the vacuum environment of the microscope (Fig. 1).
关键词: Radiolysis,Nanoparticles,Electron beam irradiation,Solvent,Liquid cell TEM
更新于2025-09-23 15:21:21
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[IEEE 2018 20th International Symposium on High-Current Electronics (ISHCE) - Tomsk, Russia (2018.9.16-2018.9.22)] 2018 20th International Symposium on High-Current Electronics (ISHCE) - Cherenkov Ka-Band Oscillator with 45% Efficiency of Beam-to-Microwave Power Conversion
摘要: The paper describes a study of a new relativistic microwave Cherenkov generator of millimeter wavelength range with the transverse dimension of the electrodynamic system D>2.5λ, where D is the average diameter of the slow wave structure, and λ is the radiation wavelength. The investigations were carried out with a high-current SINUS-200 electron accelerator at a voltage of 473 kV and an electron beam current of 3.8 kA. The use of several, complementing each other, mechanisms of suppression of parasitic waves provides stable microwave generation at a specified frequency of 36.4 GHz. The microwave power in the experiment 804 MW with 45% beam-to microwave power conversion.
关键词: amplitude modulation of high-current electron beam,slow wave structures,Cherenkov radiation,electromagnetic radiation
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - High performance carbon nanotube cold cathode for x-ray and UV devices
摘要: We developed high performance cold cathode electron beam fabrication technique with carbon nanotube(CNT) emitters. Properties of CNT emitters and its electron emission characteristics should be compatible with application devices. X-ray tubes require very high current with small cathode area and ultraviolet lamps require uniform electron emission on large area. So, we developed novel CNT electron beam with buffer and metal layer for sacrificing for structural rigidity and enhanced conductivity. We applied the novel CNT cold cathode electron beam for UV lamps and x-ray tubes for high performance UV light and x-ray image.
关键词: carbon nanotube,x-ray,electron beam,UV-C light
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Flat panel UV-C light source with CNT cold cathode electron beam (C-beam)
摘要: We developed flat panel UV-C light generation technique with the electron beam pumping technology using carbon nanotube (CNT) emitters. The wide bandgap anode material excited with high performance CNT based cold cathode electron beam (C-beam). Flat panel UV-C light generation efficiencies depend on the anode biases and current densities. With the optimized C-beam and anode, we could obtain UV-C with wavelength of 269.5 nm. Flat panel UV-C light source would be applied to many industries because advantages of flat areal light source.
关键词: carbon nanotube,UV-C light source,electron beam
更新于2025-09-23 15:21:21
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Investigation on annealing temperature-dependent optical properties of electron beam evaporated ZnSe thin films
摘要: This research work is devoted to studying optical properties of zinc selenide (ZnSe) thin films deposited by electron beam evaporation technique and annealed at different temperatures in a nitrogen environment. The structural analysis by X-ray diffraction confirmed that the obtained ZnSe films had cubic zinc-blende structure with preferred orientation along plane (111). Based on Swanepoel's envelope method, some important optical parameters such as absorption coefficient, extinction coefficient, refractive index and optical band gap, were evaluated through the transmission spectrum ranging from 300 to 1500 nm at room temperature. The optical band gap increased from 2.52 to 2.65 eV with the increasing annealing temperature. However, both the thickness and refractive index of the films decreased. In addition, the dispersion parameters of the refractive index and energy were also studied by using Wemple-DiDomenico single oscillator model.
关键词: Optical properties,Thin films,Electron beam evaporation,Zinc selenide,Thermal annealing
更新于2025-09-23 15:21:21
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Comparative Study on Microstructure and Aluminum Distribution Between Laser Beam Welding and Electron Beam Welding of Tia??6Ala??4V Alloy Plates
摘要: Ti–6Al–4V alloy plates with a thickness of 4 mm were joined by electron beam welding (EBW) and laser beam welding (LBW). The comparison of LBW and EBW was performed according to grain morphology, microstructure, aluminum distribution, and microhardness of the joints. Results indicate that compared with LBW joint, more equiaxed grains are observed around the central zone of the EBW joint. The microstructure in fusion zone (FZ) of EBW joint presents more uneven with obviously coarser acicular martensite α′. Moreover, the aluminum element content of EBW joint is substantially lower, which demonstrates a more significant burning loss behavior in EBW process. The lower aluminum content in the upper center areas of the joints is attributed to the more significant element burning loss caused by higher temperature, whereas more uniform aluminum distribution in the upper part of the joints is ascribed to stronger convection form within the upper part of the joint. In addition, the characteristics of convection and thermal field within the molten pool are recognized as vital factors influencing the aluminum distribution. The lower microhardness profile in FZ of the EBW joint is principally attributed to coarser acicular martensite α′ and lower aluminum element in EBW joint.
关键词: Electron beam welding,Microhardness,Microstructure,Burning loss,Titanium alloy,Laser beam welding
更新于2025-09-23 15:21:01
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[IEEE 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - HangZhou, China (2018.9.5-2018.9.7)] 2018 11th UK-Europe-China Workshop on Millimeter Waves and Terahertz Technologies (UCMMT) - Dispersion Characteristics of Surface Plasmon Polaritons of Graphene Loaded Three Dimensional Dielectric Gratings
摘要: Graphene has been used widely in optical and electronic devices due to its extraordinary electromagnetic characteristics. Recent theories and experiments prove that (SPPS) and graphene support surface plasmon polariton transform it into Terahertz (THz) radiation. In this paper, a dispersion and electric amplitude equations of SPPS of graphene loaded on the three dimensional dielectric gratings excited by parallel moving electron beam are derived by solving the Maxwell’s equations. The numerical results show that the frequency of amplified electric amplitude are same as the frequency point where electron beam and dispersion curve meet, which demonstrate theoretical analysis are right. The influence of dielectric gratings width is considered. It is found that the cutoff frequency occurs and rises on the dispersion curve as the width narrowing. The working point frequency is also higher compared with infinite width dielectric gratings. The SPPS of graphene loaded the three dimensional dielectric gratings whose work point is under cutoff frequency can’t be excited, even though it can be tuned. The numerical results show the electric amplitude becomes greater with width increasing.
关键词: Terahertz Radiation,Graphene,Electron Beam,Dielectric Gratings,Surface Plasmon Polariton
更新于2025-09-23 15:21:01