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• Methodology for fracture energy estimation of pores located at bonded interface is proposed. • Extended J-integral approach with proper integral path is utilized and demonstrated. • Several porosity levels and distribution of porous materials are modeled by Monte Carlo approach. • Semiconductor low-k stacked films are given as an example by using the present estimation. • Important factors of interfacial fracture are found by the response surface methodology. In view of the fracture failure mechanism induced by low interfacial strength in porous low-dielectric materials, this study establishes an approach based on fracture mechanics theory and finite element simulation to analyze different pore distribution scenarios and interfacial cracks. The study investigates the estimation method of energy release rate for the fracture tip on concerned interfaces with pores and cracks in porous stacked thin films. By incorporating the proposed finite element simulation into J-integral calculations for fracture energy release rate and comparing with previous research, the approach is reliably verified. Subsequently, using the developed simulation approach, cracks and pores in porous materials are analyzed to understand the variations of energy release rates under different structural parameters. Finally, a Monte Carlo method is considered to model porous materials and analyze the fracture energy between dissimilar material interfaces under varying porosity levels. The simulation methodology developed in this study can be applied to estimate the critical value of interfacial fracture energy for corresponding porous materials and heterogeneous material interfaces under external loads. It can serve as a criterion for structural failure assessment. [ABSTRACT FROM AUTHOR]

The embedded interposer carrier (EIC) technology for 3D-integrated circuits (3D-ICs) play an important role as a promising candidate to deal with the assembly/bonding processes of thin stacked chip and substrate. However, peeling stress of the interface between stacked via holes and copper-filled through silicon via silicon-based interposer may cause a thermomechanical reliability issue among multi-stacked film EIC architectures. For dealing with this situation, we propose a process-oriented finite element analysis method considering material nonlinear behaviors as well as process flows including process temperature and steps. This method is able to analyze systematically the effect of cycling temperature loads induced during the bonding process. From the result of simulations, it indicates that the curing process of laminated material is the critical step among the entire bonding process. In addition, the material about a compliant interposer is recommend to be a suitable solution for EIC architecture enhancing operational reliability. Furthermore, the thermal stress of each thin film stacked inside EIC structure can be relieved by means of the flexible of the carrier laminate design. [ABSTRACT FROM AUTHOR]

Abstract Multi-element nitride films of AlCrNbSiTiV high-entropy alloy (HEAs) are deposited on a cermet cutter (T1200A) and glass substrates using reactive direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HIPIMS) with a single equimolar AlCrNbSiTiV HEA target. This study determines the effect of the ratio of the nitrogen flow (varying from 0 to 40%) on the chemical composition, microstructure, mechanical properties and cutting tool performance of the (AlCrNbSiTiV)N film. The films are found to have increased hardness and elastic recovery when the nitrogen flow ratio is increased. The (AlCrNbSiTiV)N film adheres well to the substrate and the Rockwell indentation results are HF1. (AlCrNbSiTiV)N films that are grown using DCMS and HIPIMS feature only a simple face-center-cubic structure. The samples that are deposited using HIPIMS exhibit a higher film density, a smoother surface and excellent hardness and elastic recovery, compared to coatings that are deposited using DCMS. The (AlCrNbSiTiV)N films are coated onto cutters for the dry turning of a SCM440 steel work-piece. The machining surface of a coated tool that is deposited using a HIPIMS system exhibits fewer surface defects and the tool flank wear is decreased. Highlights • TEM pattern of (AlCrNbSiTiV)N film shows a simple NaCl-type FCC phase. • Nitride films shows good adhesion strength to the substrate be classified as HF1. • The distribution of elements is homogeneous through the depth of the nitride film. • The films deposited with the HIPIMS are smoother, better crystallized and good mechanical property. [ABSTRACT FROM AUTHOR]

The intrinsic stress of thin films has become an important resource as advanced strain engineering is introduced into nanoscaled semiconductor devices. The performance of preferred device infrastructure can be studied by estimating stress-induced mobility gain. However, traditional simulation approaches for device stress typically do not consider the eventual consequence of the stress gradient of strained thin films on nanoscaled transistor stress prediction. Thus, the actual operating characteristic of concerned devices can be easily misunderstood. To resolve this issue, this research presents a fabrication-oriented simulation methodology for device stress and combines it with a multi-layered deposition model for thin film. This study aims to explore stress-induced effects on the performance of a Ge-based testing vehicle for 20 nm n-type metal-oxide-semiconductor field-effect transistors (nMOSFETs) with Ge 1−x Si x alloys embedded into the source/drain regions of the device. Intrinsic stress is introduced via a 1.0 GPa tensile contact etch stop layer (CESL). Analysis results indicate that stress contours adjacent to the top of the device gate are different from those obtained using the conventional simulation method. Moreover, greater CESL stress passes through the spacer and reaches the device channel. Furthermore, a relationship between the stress components and piezoresistivity coefficients of the Ge material is adopted to estimate the width dependence of the Ge-based nMOSFET on its mobility gain. A maximum mobility gain of up to 60.87% is acquired from the estimated results, and a channel width of 200 nm is preserved. [ABSTRACT FROM AUTHOR]

The defect structures for Co 2+ in ZnO microwires, thin films and bulks are theoretically investigated by analyzing the electron paramagnetic resonance (EPR) parameters (zero-field splitting D, g factors g // and g ⊥ and hyperfine structure constants A // and A ⊥ ) for trigonally distorted tetrahedral 3d 7 clusters in a consistent way. The impurities Co 2+ are found to suffer the displacements (≈0.046, 0.044 and 0.045 Å) away from the ligand triangles along the C 3 axis in ZnO microwires, thin films and bulks, respectively, which considerably reduce the trigonal distortions of the Zn 2+ sites in the hosts. Apart from the contributions from the conventional crystal-field (CF) mechanism, those from the charge-transfer (CT) mechanism are important and should be included in the EPR analysis. The defect structures and spectral properties of the three ZnO:Co 2+ systems are discussed. [ABSTRACT FROM AUTHOR]

The suitability of stacked thin films for next-generation display technology was analyzed based on their properties and geometrical designs to evaluate the mechanical reliability of transparent conducting thin films utilized in flexural displays. In general, the high bending stress induced by various operation conditions is a major concern regarding the mechanical reliability of indium-tin-oxide (ITO) films deposited on polyethylene terephthalate (PET) substrates; mechanical reliability is commonly used to estimate the flexibility of displays. However, the pattern effect is rarely investigated to estimate the mechanical reliability of ITO/PET films. Thus, this study examined the flexible content of patterned ITO/PET films with two different line widths by conducting bending tests and sheet resistance measurements. Moreover, a stress-strain simulation enabled by finite element analysis was performed on the patterned ITO/PET to explore the stress impact of stacked film structures under various levels of flexural load. Results show that the design of the ITO/PET film can be applied in developing mechanically reliable flexible electronics. [ABSTRACT FROM AUTHOR]

This study employed the four-point bending test (4-PBT) to measure the interfacial strength of pressure-sensitive adhesive (PSA)/SiN passivation stacked thin films. Finite element analysis (FEA) is combined with the J integral approach and the modified virtual crack closure technique to validate the results of 4-PBT. The FEA simulation results verify the measurement results. The stress status and energy release rate of the delaminated tip are also determined at different elevations of stacked thin films of 4-PBT specimens adjacent to the PSA/SiN interface. The crack in the PSA parallel to the foregoing interface with a slight span occurs on the fractured interface. This behavior is confirmed by observing the scanning electron micrographs of the specimens after 4-PBT. [ABSTRACT FROM AUTHOR]

Abstract: Developing a robust predicting methodology on the interfacial fracture energy of dissimilar materials is urgently needed to meet the mechanical strength requirements for investigating novel materials and subsequent device structures with the bonded types of multi thin films. Thus, this paper provides an overview of useful approaches according to linear-elastic interfacial fracture mechanics, such as J-integral method, modified virtual crack closure technique (MVCCT), and analytical solutions derived from the relationship between the stress field of delaminated tip and crack tip opening displacements to compare their estimated capability of cracking energy. A popular technique for determining the interface adhesion of thin coatings is the four-point bending test (4-PBT). The testing vehicles of 4-PBT allow a more thorough validation of the foregoing predicted approaches based on finite element analysis compared with the simulated results with related experimental data. The critical energies of 18J/m2, 78.53J/m2, 52.01J/m2, and 71.02J/m2 for the bonded interfaces of SiO2/SiLK, Ta/SiLK, TaN/SiLK, and Si3N4/SiLK stacked nano-scaled thin films are precisely judged, respectively. The predicted results of the J-integral method match well with the MVCCT estimation. The results reveal that the opening fractured mode is dominant at the beginning of the crack advances along the bonded interface of Ta/SiLK, TaN/SiLK, and Si3N4/SiLK stacked films as the interfacial crack length increases. Moreover, the essential trends of dependences for the modulus ratio and thickness ratio of stacked thin films on interfacial energy release rate are logically identified and investigated. Therefore, this paper could be regarded as a design guideline of interfacial fracture behavior for stacked films utilized in the development of advanced device technologies. [Copyright &y& Elsevier]

Abstract: The integration of thin film technology into the fabrication of semiconductor transistors has given rise to significant challenges in the design of multi-level back-end-of-line interconnects. The interfacial adhesion between Al metal and TiN barrier is one of the major factors that affect interconnect reliability. Analyzing the effect of the interconnect structures of Al/TiN barriers on interfacial cracking energy under flexural loading is an interesting research direction. This work proposes a robust estimation of interfacial cracks by simulation-based methods to satisfy the mechanical design requirements for multi-level interconnect systems. A constant bending moment can be generated with the framework of the four-point bending test (4-PBT). A 4-PBT simulation model can be used in finite element analysis, combined with the J-integral method and the modified virtual crack closure technique, to accurately predict the interfacial fracture energy of Al/TiN films. Preliminary results indicate a considerable increase in energy release rate. Energy is released as a crack along the interface of the Al/TiN films passes through the region above the parallel metal lines of patterned interconnects, especially for a Cu/SiLK material system. The results also show that dielectrics can serve as stress buffer layers that inhibit crack growth. [Copyright &y& Elsevier]

Abstract: Organic electronic devices with multi-stacked thin films based on polymeric substrates are proposed for use in mainstream flexible organic light-emitting diode displays. To achieve the above-mentioned requirements, indium tin oxide (ITO) thin film, a brittle, inorganic material, is necessary to be utilized as a transparent electrode in flexible electronics. The failure rate of ITO films is of concern when introducing harsh flexural load in terms of reliability. This study utilizes a simulation-based factorial-design approach to determine a suitable combination of mechanical characteristics of ITO film stacked with other films to reduce the neutral plane (NP) impact of stacked films. The results indicate that both Young's modulus and cover plate thickness are major factors that alter the stress magnitude of ITO films. Moreover, the simulated results for stacked structures reveal that the distance between the ITO film and NP is significantly reduced when polyimide materials, rather than steel metal, are used for the cover plate. In the meanwhile, ITO film stress drops in virtue of lower mechanical stiffness and lesser thickness direction between the NP and ITO films in a multi-stacked film structure. [Copyright &y& Elsevier]

Abstract: The interfacial adhesion of thin films between Al metal and TiN barrier is one of the major concerns dominating the mechanical reliability of semiconductor devices. The measured accuracy of cracking energy for stacked films with a nanoscale order is arduous to preserve because of the uncertainty in specimen preparations and instrumental operations. Consequently, the present research proposes a robust estimation of interfacial cracks using simulation-based methodologies to meet the requirement for mechanical designs in multi-level interconnected systems of electronic devices. According to the framework of the four-point bending test (4-PBT), the interfacial fracture energy of Al/TiN films is predicted via finite element analysis (FEA), combined with the J-integral method and modified virtual crack closure technique (VCCT). The foregoing simulated approaches are also verified by related analytical solutions and experimental data. Moreover, the effects of several patterned types of metal lines underneath the Al/TiN interface with various embedded cracks are analyzed. The primary results highlight a significant increase in the energy release rate (G) induced by the passing of a crack along the interface of Al/TiN films through the region below a metal line with a high degree of hardness. Dielectrics with a lower modulus would have the capacity to restrain progressive crack growth. Thus, a high G is expected to drop, as simultaneously demonstrated by the present simulated methodologies. [Copyright &y& Elsevier]

Abstract: Formation and composition analyses of titanium oxinitride nanocrystals (NCs) fabricated via treating a magnetron co-sputtered thin film of titanium and silicon dioxide with a rapid thermal annealing in nitrogen ambient were demonstrated for nonvolatile memory applications. Phase separation characteristics with different annealing conditions were examined by transmission electron microscopy and chemical bonding characteristics were confirmed by X-ray photon emission spectra. It was observed that a blanket layer composed mainly of titanium oxide was still present as annealing temperature was increased to 700°C, associated with the thermodynamically stable phase of titanium oxide. Furthermore, a higher thermal treatment of 900°C induced formation of a well-separated NC structure and caused simultaneously partial nitridation of the titanium oxide, thereby forming titanium oxinitride NCs. A significant capacitance–voltage hysteresis in threshold voltage shift at 1V was easily achieved under a small sweeping voltage range of +2V/−2V, and a memory window retention of 2.2V was obtained after 107 s by extrapolation under a 1s initial-program/erase condition of +5V/−5V, respectively. [Copyright &y& Elsevier]

Abstract: The main problem of printed carbon nanotube film (CNTF) is that emitters do not have distributed uniformity. CNT was buried in leftover binding materials, which needs to be removed by fitted sintering and post-treatment. A new paste for printed CNTF was developed. Tunneling coefficients of leftover potential barrier were calculated respectively by the numerical method. The electrons translocation results through potential barrier between CNTs in calculated CNTF were tested by an experiment. A novel post-treatment, including high-temperature sintering and mechanical shearing and blowing, was performed to evidently improve the electron translocation and field emission current density of CNTF. Excellent emission prosperities were exhibited: stable current density, distributed uniformity emitters and long lifetime. The treatment of high-temperature sintering and mechanical shearing and blowing, may be an important prerequisite for future field emission display. [Copyright &y& Elsevier]

In order to resolve the issues of RC time delay and high power consumption, IC chips with Cu/low-k interconnects are developed to meet the foregoing requirements. However, there is a high potential that in doing so it may contribute to interfacial cracks occurring or propagating between the copper metal and the low-k dielectric material as a result of poor adhesion and lower fracture toughness, which results from the inherent mechanical imperfection of low-k materials. This fracturing problem is one of the most urgent issues for the thermomechanical reliability of Cu/low-k interconnects, and it needs to be resolved urgently. For this reason, we propose a prediction methodology of finite-element analysis (FEA) based on J-integral value estimation to investigate the interfacial fracture opportunity of low-k packages. However, the J-integral calculation is path dependent and so crucial in FEA for a crack on an interface between dissimilar materials. Therefore, various paths with an integral contour surrounding the crack tip are considered to avoid a misunderstanding of the cracking energy. All the analytic results indicate that a rectangular contour with a proper ratio of length/width, and multilayers of element close to the delaminating surfaces, is suggested for obtaining a stable J-integral value. On the other hand, the proposed methodology has been validated by a four-point bending test and compared with the relative experimental data of multi-low-k dielectric films. Moreover, under a reliable integral contour path that crack driving force predicted using the type of interfacial crack constructed by means of the element death technique, it shows good agreement with the simulated results of embedding actual crack. [ABSTRACT FROM AUTHOR]

Based on wavelet transforms extracting characteristic features from experimental data, the wavelet neural network (WNN) is used as an elementary model to study the characteristics of field emission from thin films. The WNN model is trained with learning samples of thin film thickness. The function mappings that the trained WNN model contains are the very ones that thin film thickness varies with characteristic parameters of field emission. A predicting model on thin film thickness of field emission is obtained. The data of thickness of diamond thin films is used to test this model. The results show that the absolute value of the relative error is within 2.98%, and the well-trained WNN model possesses good forecasting characteristics. [Copyright &y& Elsevier]

ZnO nanocrystal thin films were fabricated on sapphire substrates by laser molecular beam epitaxy. The structure and optical properties of the films were investigated experimentally. The film having small nanocrystal size of about 50–200 nm shows optically pumped ultraviolet laser emission at room temperature. This paper discussed the theoretical mechanism of excitonic radiative recombination in relation with the nanocrystal structure on ZnO film ultraviolet laser research. It is concluded that the experimental results are consistent with the theoretical analysis. [Copyright &y& Elsevier]

The design of multicomponent materials has captured considerable attention due to its extraordinary ability to tailor functional properties. However, how a single element affects the behavior of the overall material has yet to be explored in depth. In this study, the heteroepitaxy of high entropy (Fe, Co, Ni, Cr, Mn)3O4 films with varying strain states are investigated in magnetic performance. It is discovered that the high entropy oxide thin film with compressive strain exhibits an effect of crystalline magnetic anisotropy. Diverse analyses provide a detailed understanding of high entropy magnetic oxide systems, including X‐ray diffraction, reciprocal space mapping, macroscopic magnetic characterization, X‐ray absorption spectroscopy (XAS), etc. Notably, the element‐specific XAS technique proves effective in uncovering the origin of the crystalline magnetic anisotropy. Due to the substrate‐induced epitaxial strain, the eg orbitals of Mn3+ form different energy levels, leading to different preferred electron occupancy. The exploration of magnetic properties in epitaxial high entropy oxide film is then raveled. By navigating the complexities introduced by the random atom distribution and intricate magnetic interactions, this study pioneers novel methodologies for probing the core physics of high entropy oxides. [ABSTRACT FROM AUTHOR]

The origin of insulating ferromagnetism in epitaxial LaCoO3 films under tensile strain remains elusive despite extensive research efforts are devoted. Surprisingly, the spin state of its Co ions, the main parameter of its ferromagnetism, is still to be determined. Here, the spin state in epitaxial LaCoO3 thin films is systematically investigated to clarify the mechanism of strain‐induced ferromagnetism using element‐specific X‐ray absorption spectroscopy and dichroism. Combining with the configuration interaction cluster calculations, it is unambiguously demonstrated that Co3+ in LaCoO3 films under compressive strain (on LaAlO3 substrate) is practically a low‐spin state, whereas Co3+ in LaCoO3 films under tensile strain (on SrTiO3 substrate) have mixed high‐spin and low‐spin states with a ratio close to 1:3. From the identification of this spin state ratio, it is inferred that the dark strips observed by high‐resolution scanning transmission electron microscopy indicate the position of Co3+ high‐spin state, i.e., an observation of a spin state disproportionation in tensile‐strained LaCoO3 films. This consequently explains the nature of ferromagnetism in LaCoO3 films. The study highlights the importance of spin state degrees of freedom, along with thin‐film strain engineering, in creating new physical properties that do not exist in bulk materials. [ABSTRACT FROM AUTHOR]

Deals with a study which investigated the deposition and properties of in situ boron-doped polycrystalline silicon films, using an ultrahigh vacuum chemical vapor deposition system. Details of polycrystalline silicon films deposited with low pressure chemical vapor deposition techniques; Methodology of the study; Results and discussion.

This work analyses the overall stress/strain characteristic of flexible encapsulations with organic light-emitting diode (OLED) devices. A robust methodology composed of a mechanical model of multi-thin film under bending loads and related stress simulations based on nonlinear finite element analysis (FEA) is proposed, and validated to be more reliable compared with related experimental data. With various geometrical combinations of cover plate, stacked thin films and plastic substrate, the position of the neutral axis (NA) plate, which is regarded as a key design parameter to minimize stress impact for the concerned OLED devices, is acquired using the present methodology. The results point out that both the thickness and mechanical properties of the cover plate help in determining the NA location. In addition, several concave and convex radii are applied to examine the reliable mechanical tolerance and to provide an insight into the estimated reliability of foldable OLED encapsulations. [ABSTRACT FROM AUTHOR]

Zr-based thin film metallic glass (TFMG), exhibiting the unique properties of good glass forming ability (GFA), corrosion resistance, and biocompatibility, can be applied in various novel fields of industries. An ultra-smooth surface is obtained with the TFMG coatings, which is beneficial to modify the work surface. Thus, TFMG can be extended to medical appliances, such as surgical blades and micro-surgery scissors. The aims of this study are to fabricate the Cu-containing Zr-based TFMG onto SUS304 plates and to investigate the surface physical properties and their antimicrobial effects. The chemical compositions of Zr–Cu–Ni–Al coatings are examined by a field emission electron probe micro-analyzer (FE-EPMA). The amorphous structures of all TFMG are characterized by the X-ray diffractometry. The surface properties are analyzed by an atomic force microscope (AFM) and a water contact angle goniometer for the 304 stainless steel substrate and Zr–Cu–Ni–Al TFMG. Liquid culture methods and plate counting methods are used to assess the antimicrobial performance of specimens. The antimicrobial rate against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) under the Japanese Industrial Standard JIS Z2801: 2000 is over 99%. The release of copper ion from TFMG specimen is determined by the inductively coupled plasma-mass spectrometer (ICP-MS) to evaluate the antimicrobial activity of Cu-containing Zr-based TFMG. The results show that the surface of SUS 304 stainless steel substrate can be modified with deposited Zr–Cu–Ni–Al TFMG, and their improved antimicrobial efficacy against those bacteria is attributed to their amorphous rough surface, hydrophobic properties and released copper ion. The TFMG developed in this study with adequate hardness, good adhesion ability and antimicrobial efficiencies can be used as a promising candidate to improve the surface properties of the medical appliances and also to reduce the possibility of nosocomial infection. [ABSTRACT FROM AUTHOR]

Presents a study which investigated the deposition of in situ boron-doped polycrystalline silicon-germanium films grown at low temperatures. Use of an ultrahigh-vacuum/chemical-vapor deposition system in the study; Description of the system; Experimental details.

Development of metallic thin films with comprehensive properties fulfilling the needs of modern Micro/Nano Electro Mechanical Systems (M/NEMS) devices remains challenging. Here, a fully amorphous Ta 90 Co 10 is screened out by combinatorial sputtering and atomic manufacturing technique, and the Ta 90 Co 10 thin film metallic glass exhibits simultaneously a super-high crystallization temperature of 1325 K, a high hardness of 16.3 GPa, a high strength of 5000 MPa, and a large plastic strain exceeding 50%, outperforming all existing thin film materials. The excellent properties can be attributed to the atomic-scale structural heterogeneity induced by formation of different configurations in amorphous structure. The present work provides an approach to develop new M/NEMS-based thin film materials with outstanding comprehensive properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Boron-doped ZnO (BZO) films deposited by metal organic chemical vapor deposition (MOCVD) generally act as transparent conductive oxide films in hydrogenated amorphous silicon (a-Si:H) solar cells and exhibit a high external quantum efficiency (EQE) performance in the short-wavelength region. They, therefore, facilitate efficient use of sunlight in solar cells. However, sharp surface features on the BZO film may result in nano-cracks and voids in the cells. In this study, we devised a process for modifying these sharp features. The BZO films were smoothened by performing a sputtering hydrogen-doped ZnO (HZO) layer using a magnetron sputtering system. The a-Si:H solar cells based on BZO films subjected to this treatment exhibited a higher open-circuit voltage ( V oc ), fill factor ( FF ), and efficiency; however, their short-circuit current density ( J sc ) decreased slightly. In an attempt to increase the J sc while maintaining a high electrical performance for the solar cells, we deposited an additional thin BZO film on the sputter-treated one to realize a micro- and nano-textured structure. This strategy succeeded in increasing J sc and also caused a further improvement in the V oc , FF , and efficiency. As a result, over 10% efficiency of a-Si:H solar cells based on BZO electrodes with a micro- and nano-textured structure was achieved. Moreover, the thickness of the cell is only 300 nm. [ABSTRACT FROM AUTHOR]

(WO3)100−XCX thin films (x \(=\) 0−9.3 at%) were cosputtered on indium-tin-oxide glass substrate with W and C targets by reactive dc magnetron sputtering at room temperature. The effects of doped C on the microstructure and optical properties of the (WO3)100−XCX thin film were examined by field emission scanning electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, and a spectrophotometer. It was found that all of the as-deposited films were amorphous. The average transmittances of bleaching and colored WO3 film in the 400–700 nm range were 75% and 65.9%, respectively. The variation in average transmittance of the bleaching and colored states of (WO3)90.7C9.3 film was 68.3%. The average transmittance of bleaching (WO3)100−XCX thin films did not vary with C doping. However, the average transmittance of colored (WO3)100−XCX film decreased to <48% after C doping. In addition, the optical transmittance contrast of (WO3)100−XCX thin films was found to be suitable for blue laser wavelength recording. [ABSTRACT FROM PUBLISHER]

Abstract: Photocatalytic TiO2 thin films were prepared via an electron beam-induced deposition (EBID) method. The effects of post-calcination treatment on the properties of the prepared TiO2 thin films were studied. X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectrometry (SEM-EDS), and UV–V is absorption spectrometry were performed to reveal the crystallinity, surface morphology, chemical composition, and light absorbance of the prepared TiO2 thin films. The photoelectrochemical characteristics of the TiO2 thin films were investigated with a potentiostat. Under UV irradiation, a photocurrent of ˜2.1 mA was observed for the TiO2 thin film with post-calcination at 500 °C. A water-splitting reaction was conducted over the TiO2 thin film with the best photoelectrochemical performance. The yields of hydrogen and oxygen were 59.8 and 30.6 μmole, respectively, after 8 h of reaction under UV irradiation. [ABSTRACT FROM AUTHOR]

The nanoindentation technique was used to measure the hardness and Young's modulus of semiconductor and metal thin films on a Si(100) substrate under cyclic loading. The results showed that in all instances and at a constant cyclic load that the loading curves overlapped the previous unloading curve and had a small displacement after each cyclic nanoindentation. It was observed that the plastic energies of metal materials from the first loading–unloading cycle were much larger than that observed in semiconductor materials. Furthermore, the hardness and Young's modulus of the thin films decreased when the number of cyclic nanoindentations was increased. The effect of the cyclic loading on the hardness and Young's modulus of semiconductor material was much larger than that of the metal material. Young's modulus, the hardness and the contact stiffness of thin films conform to the relationship that Young's modulus was proportional to the contact stiffness and the square root of the thin film's hardness. [ABSTRACT FROM AUTHOR]

This research explores the behavior of Co40Fe40W10B10 when it is sputtered onto Si(100) substrates with a thickness (tf) ranging from 10 nm to 100 nm, and then altered by an annealing process at temperatures of 200 °C, 250 °C, 300 °C, and 350 °C, respectively. The crystal structure and grain size of Co40Fe40W10B10 films with different thicknesses and annealing temperatures are observed and estimated by an X-ray diffractometer pattern (XRD) and full-width at half maximum (FWHM). The XRD of annealing Co40Fe40W10B10 films at 200 °C exhibited an amorphous status due to insufficient heating drive force. Moreover, the thicknesses and annealing temperatures of body-centered cubic (BCC) CoFe (110) peaks were detected when annealing at 250 °C with thicknesses ranging from 80 nm to 100 nm, annealing at 300 °C with thicknesses ranging from 50 nm to 100 nm, and annealing at 350 °C with thicknesses ranging from 10 nm to 100 nm. The FWHM of CoFe (110) decreased and the grain size increased when the thickness and annealing temperature increased. The CoFe (110) peak revealed magnetocrystalline anisotropy, which was related to strong low-frequency alternative-current magnetic susceptibility (χac) and induced an increasing trend in saturation magnetization (Ms) as the thickness and annealing temperature increased. The contact angles of all Co40Fe40W10B10 films were less than 90°, indicating the hydrophilic nature of Co40Fe40W10B10 films. Furthermore, the surface energy of Co40Fe40W10B10 presented an increased trend as the thickness and annealing temperature increased. According to the results, the optimal conditions are a thickness of 100 nm and an annealing temperature of 350 °C, owing to high χac, large Ms, and strong adhesion; this indicates that annealing Co40Fe40W10B10 at 350 °C and with a thickness of 100 nm exhibits good thermal stability and can become a free or pinned layer in a magnetic tunneling junction (MTJ) application. [ABSTRACT FROM AUTHOR]

Abstract: Polycrystalline silicon thin film transistors (poly-Si TFTs) with the ion implantation of fluorine elements were investigated in this study. The electrical performance and reliability were reported comprehensively. Experimental work has shown the electrical characteristics of excimer laser crystallized F-ions-implanted poly-Si TFTs are improved effectively, especially for field effect mobility. It is also found that the fluorine piled up at the poly-Si interface during thermal annealing, for the TFT fabricated without a prior deposition of pad oxide. The stronger Si–F bonds replace the Si–Si/Si–H, leading to the superior electrical reliability. However, the dose of F ions is critical in poly-Si, or the electrical characteristics of TFT devices will be degraded. [Copyright &y& Elsevier]

Abstract: Poly-Ge grown on SiO2 substrates by using one-step ultra-high vacuum chemical vapor deposition (UHVCVD) process with thin Si nucleation layers at very low deposition temperature (350 °C) was demonstrated. The results demonstrated that the polycrystalline silicon (poly-Si) nucleation layer is needed for the growth of polycrystalline germanium (poly-Ge) on SiO2 substrates at low growth temperature. SEM image presents the films with uniform grain size and uniform thickness occurring in the samples. The grain size of poly-Ge is about 100 nm. The Raman shift spectrum and XRD spectrum also identified that films are high quality poly-Ge by using this method. [Copyright &y& Elsevier]

Abstract: Influence of silane concentration (SC), substrate temperature (Ts) and substrates on the properties of materials deposited by very high frequency plasma enhanced chemical vapor deposition was studied. SC and Ts had a great impact on the structure of materials, especially changed from amorphous to microcrystalline silicon. The results of FTIR (flourier transform infrared) showed that material fabricated at higher temperature appeared a little oxygen peak located at 1017cm−1, which means that oxygen easily entered into the materials at higher Ts. However, microcrystalline silicon thin film prepared at low Ts easily adsorbed oxygen characterized with oxygen content increased largely with the prolong of time. The results of Raman evidently showed that crystalline volume fraction (Xc) also depended on the type and texture of substrate. Higher texture means higher volume crystalline fraction for the same type of substrate. [Copyright &y& Elsevier]

Abstract: The high purity ZnO ceramic target and the (MgO)0.1(ZnO)0.9 target were fabricated. The wurtzite-phase ZnO thin film and ternary MgxZn1-xO thin film were grown on sapphire (0001) substrates by laser molecular beam epitaxy (L-MBE) from the sintered ceramic targets separately. The films'' transmittance spectra at room temperature for the ZnO film and the MgxZn1-xO film were measured and compared while their room temperature photoluminescence spectra were done. The band-gap modulation is realized from 3.31eV for the ZnO film to 3.64eV for the MgxZn1-xO alloy film. The Mg content x in the MgxZn1-xO alloy film was determined to be 0.18. [Copyright &y& Elsevier]

We have fabricated a polycrystalline silicon thin-film transistor with self-aligned SiGe raised source/ drain (SiGe-RSD TFT). The SiGe-RSD regions were grown selectively by ultrahigh vacuum chemical vapor deposition at 550 °C. It was observed that, with SiH[sub 4] and GeH[sub 4] gas flow rates of 5 and 2 sccm, respectively, the poly-SiGe could be selectively grown up to 100 nm for source/drain regions. The resultant transistor structure features an ultrathin active channel region (20 nm) and a self-aligned thick source/drain region (120 nm), which is ideally suited for optimum performance. The significant improvements in electrical characteristics, such as higher turn-on current, lower leakage current, and higher drain breakdown voltage have been observed in the SiGe-RSD TFT, compared to the conventional TFT counterpart. These results indicate that TFTs with SiGe raised source/drain structure would be highly promising for ultrathin TFTs applications. [ABSTRACT FROM AUTHOR]