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Oxygen vacancy is crucial to the optical properties in In 2 O 3 , however, the single oxygen vacancy model fails to explain the observed multi-peak emission in the experiment. Herein, we have theoretically investigated the diversity of oxygen vacancy distribution, revealing the relationship between the defect configurations and the optical properties. Combining the first-principles calculations and bayesian regularized artificial neural networks, we demonstrate that the structural stability can be remarkably enhanced by multi-oxygen vacancy aggregation, which will evolve with the defect concentration and temperature. Notably, our results indicate that the single oxygen vacancy will induce the emission peaks centered at 1.35 eV, while multi-peak emission near 2.35 eV will be attributed to the distribution of aggregated double oxygen vacancies. Our findings provide a comprehensive understanding of multi-peak emission observed in In 2 O 3 , and the rules of the vacancy distribution may be extended for other metal oxides to modulate the optical properties in practice. [ABSTRACT FROM AUTHOR]

Water balloons and water drops are different objects, yet the work by Chang ["On the similarities between the resonance behaviors of water balloons and water drops," Phys. Fluids 32, 124113 (2020)] reveals the similarities between their resonance behaviors. Chang's work focuses on the balloons with pinning angles beyond 90° (superhemispherical balloons), and the results are based on a limited number of modes. In this study, the resonance of balloons with pinning angles below 90° (subhemispherical balloons) is examined. The setup is similar to that for Chang's work, except each balloon is enlarged to possess a larger inertia, and a correlation-based method is adopted to visualize the balloon's oscillation. With these improvements, this study successfully discovers more than 37 modes, many of them have not been reported in the literature. For these modes, a catalogue is constructed to demonstrate their one-to-one correspondence to the modes of drops. Additionally, a scaling scheme is proposed to assimilate the resonance frequencies of subhemispherical balloons and drops. With these, this study provides a simple framework for predicting a subhemispherical water balloon's resonance with a theory for the resonance of sessile drops on a flat plate. [ABSTRACT FROM AUTHOR]

Tangled magnetic fields, often coexisting with an ordered mean field, have a major impact on turbulence and momentum transport in many plasmas, including those found in the solar tachocline and magnetic confinement devices. We present a novel mean field theory of potential vorticity mixing in β-plane magnetohydrodynamic (MHD) and drift wave turbulence. Our results show that mean square stochastic fields strongly reduce Reynolds stress coherence. This decoherence of potential vorticity flux due to stochastic field scattering leads to suppression of momentum transport and zonal flow formation. A simple calculation suggests that the breaking of the shear-eddy tilting feedback loop by stochastic fields is the key underlying physics mechanism. A dimensionless parameter that quantifies the increment in power threshold is identified and used to assess the impact of stochastic field on the L-H transition. We discuss a model of stochastic fields as a resisto-elastic network. [ABSTRACT FROM AUTHOR]

In this study, the resonance of water balloons is examined, and an understanding of their dynamics in terms of our knowledge about resonating sessile drops is reported. The focus is the regime in which the competition between surface and inertial forces dominates the dynamics of the balloon. In experiments, water balloons are mechanically oscillated along their axes of symmetry, and their responses are observed through optical imaging. The observations are compared to the resonance of sessile drops. Balloons differ from drops for having elasticity in place of surface tension. Different as balloons and drops may seem, this study reveals great similarities between them: a resemblance of their normalized pressure–volume curves, a one-to-one shape correspondence between their eigenmodes, and a close approximation of their normalized resonance frequencies. Based on these, turning a drop into a balloon preserves the drop's mechanical response to a large extent. In fact, as a first approximation, the water balloons respond mechanically as water drops with a much higher surface tension. [ABSTRACT FROM AUTHOR]

The Fourier transform Coulomb (FTC) method has been shown to be effective for the fast and accurate calculation of long-range Coulomb interactions between diffuse (low-energy cutoff) densities in quantum mechanical (QM) systems. In this work, we split the potential of a compact (high-energy cutoff) density into short-range and long-range components, similarly to how point charges are handled in the Ewald mesh methods in molecular mechanics simulations. With this linear scaling QM Ewald mesh method, the long-range potential of compact densities can be represented on the same grid as the diffuse densities that are treated by the FTC method. The new method is accurate and significantly reduces the amount of computational time on short-range interactions, especially when it is compared to the continuous fast multipole method. [ABSTRACT FROM AUTHOR]

We report super-resolution imaging in a metamaterial system comprising spherical silver nanoparticle chain arrays, where each chain consists of nanoparticles with a smaller particle added to the end. Our simulations reveal that silver nanoparticale chains have subwavelength resolution capability at visible wavelengths and that the field intensity in the imaging plane varies with the number of layers of nanoparticles, their polarization, and their coupling. By adding a smaller nanoparticle at the end of each chain, the resolution capability is significantly enhanced, and high-quality super-resolution imaging can be realized for incident waves polarized along the chain direction. [ABSTRACT FROM AUTHOR]

The coarse-grained configurational-bias Monte Carlo simulation was used to investigate structural behaviors of methyl methacrylate (MMA)-oligomers adsorbed on grooved substrates with different aspect ratios. In this study, three types of chains are classified according to their positions relative to the groove. Types 1, 2, and 3 represent the entire MMA-oligomer within the groove, the MMA-oligomer partially within the groove, and the oligomer outside the groove, respectively. The orientational order parameters of types 1 and 2 oligomers decrease with the increase of groove width, but the orientational order parameter of type 3 oligomers is approximately equal to 0.1. In addition, observation of the orientational order parameters of type 1 oligomers interacting with the grooved substrate at different interaction strengths decrease with increasing the groove width. Furthermore, the orientational order parameters of type 1 oligomers within the narrowest (20 Å) and the widest (35 Å) groove with different depths were determined. For the narrowest groove, the arrangement of type 1 oligomers will be influenced by the groove width. However, in the case of the widest groove, the orientational order parameter of type 1 oligomers is approximately equal to 0.2. [ABSTRACT FROM AUTHOR]

The acoustic pseudospin edge states characterized by backscattering immunity and unidirectional transport provide a basis for designing devices with unconventional functions. In this Letter, we report pseudospin-layer coupled acoustic topological edge states realized by two layers of coupled honeycomb sonic crystals. With the additional layer degree of freedom, we define two distinctly different topological invariants that collectively determine the direction of the acoustic vortex and the layer polarization. We achieve an interesting phase diagram and explore the edge states between different phases. Additionally, we extend the topological edge states to the heterostructure and experimentally verify its capability to focus acoustic waves and convert layer polarization. Our work may provide a feasible platform for the manipulation of acoustic waves and could have promising applications in various areas, such as acoustic signal transmission and splitting. [ABSTRACT FROM AUTHOR]

The Ce3+/Eu2+ coactivated Sr3B2O6 phosphors exhibit varied hues from blue through white and eventually to yellow-orange by resonance-type energy transfer from Ce3+ to Eu2+ and tuning the relative proportion of Ce3+/Eu2+ properly. The authors have demonstrated that electric dipole-dipole interaction dominates the energy transfer mechanism in Sr3B2O6:Ce3+,Eu2+ phosphor, and the critical distance of energy transfer has been estimated to be about 30 Å by both spectral overlap and concentration quenching methods. They have also shown that under the excitation of UV radiation, white light is generated by coupling 434 and 574 nm emission bands attributed to Ce3+ and Eu2+ radiations, respectively. [ABSTRACT FROM AUTHOR]

The authors report experiments with a diffraction-based biosensor based on self-assembly of target-containing nanobeads that form optical diffraction gratings. They demonstrate that the diffraction signal is a function of the bead size, and that noise is minimized by normalizing the intensities of the diffraction modes. They characterize the dependence of the diffraction signal on equivalent bead size and demonstrate the potential of the scheme in detecting biologically significant molecules. [ABSTRACT FROM AUTHOR]

Yellowish green-to-orange red emission can be generated by energy transfer from Eu2+ to Mn2+ in the Ca2MgSi2O7 host matrix. Eu2+-doped Ca2MgSi2O7 shows a broad green emission band centering at 528 nm and Mn2+-doped Ca2MgSi2O7 exhibits a red emission at around 602 nm. The authors have demonstrated that the mechanism of energy transfer from Eu2+ to Mn2+ in Ca2MgSi2O7:Eu,Mn phosphor is a resonant type via a dipole-quadrupole mechanism. They have also shown that the white light with varied hue, depending on contents of Mn2+, is generated by combination of predesigned emission wavelength-tunable Ca2MgSi2O7:Eu,Mn phosphors and violet-blue light source. [ABSTRACT FROM AUTHOR]

The UV spectrum of CH³CHOO was measured by transient absorption in a flow cell at 295 K. The absolute absorption cross sections of CH³CHOO were measured by laser depletion in a molecular beam to be (1.06 ± 0.09) × 10-17 cm² molecule-1 at 308 nm and (9.7 ± 0.6) × 10² molecule-1 at 352 nm. After scaling the UV spectrum of CH³CHOO to the absolute cross section at 308 nm, the peak UV cross section is (1.27 ± 0.11) × 10-17 cm² molecule-1 at 328 nm. Compared to the simplest Criegee intermediate CH2OO, the UV absorption band of CH³CHOO is similar in intensity but blue shifted by 14 nm, resulting in a 20% slower photolysis rate estimated for CH³CHOO in the atmosphere. [ABSTRACT FROM AUTHOR]

We investigated multilevel resistance switching characteristics of the thin FeOx transition layer in a TiN/SiO2/FeOx/Fe structure by controlling the current compliance and stopped voltage during the set and reset processes, respectively. It is observed that the resistive state could be easily tunable by controlling external electric conditions. The multilevel memristive mechanism was characterized by distinguishing the electrical behaviors statistically, inferring that the reset process is associated with the mobile-ion-assisted electrochemical redox. Moreover, the set process is also modeled by power dissipation behaviors. The presented mathematical and physical model provides a possibility to elucidate a universal mechanism for bipolar multilevel memristor. [ABSTRACT FROM AUTHOR]

The characteristics and reliability of laser-activated polycrystalline silicon thin-film transistors (poly-Si TFTs) under the stress condition of drain voltage (V[sub d]) = 12V and gate voltage (V[sub g]) = 15 V have been investigated. In spite of reducing the source/drain resistivity by using laser activation method, the leakage current (V[sub g] < 0) is larger for laser-activated poly-Si TFTs in comparison with traditional furnace-activated counterparts. It is also found that the post-stress leakage and on/off current ratio degrade much faster for laser-activated poly-Si TFTs, while the degradation rates of threshold voltage and subthreshold swing are comparable to those of traditional furnace-activated TFTs. The laser activation modifies the grain structure between drain and channel region and causes grain discontinuity extending from the drain side to the channel region. The grain discontinuity near drain side in the polysilicon film has been investigated by transmission electron microscopy analysis. The effective trap state density calculated from typical I-V curve has been compared for laser-activated and furnace-activated TFTs. As a result, an inferior reliability with extra trap state density and larger leakage current was observed in the laser-activated poly-Si TFTs. [ABSTRACT FROM AUTHOR]

Strained boron-doped Si[sub 1-x]Ge[sub x] layers with different Ge mole fractions were selectively deposited by ultrahigh vacuum chemical molecular epitaxy to form shallow p[sup +]-n junction suitable for raised source/drain metal-oxide-semiconductor field effect transistor applications. Detailed electrical characterizations were performed. Our results show that the reverse leakage current could be optimized by a rapid thermal annealing at 950 °C for 20 s, and a near perfect forward ideality factor (i.e., <1.01) is obtained for the p[sup +]-n Si[sub 1-x]Ge[sub x]/Si junction. By analyzing the periphery and area leakage current components of p[sup +]-n Si[sub 1-x]Ge[sub x]/Si junctions with various perimeter lengths and areas, the degree of misfit dislocations and undercut effect were studied. The specific contact resistance was found to decrease as Ge mole fraction increases. Junction depth measurements also show that the junction depth decreases monotonically with increasing Ge mole fraction. The reduced B diffusion constant is attributed to the increasing Ge gradient in the transition region. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The development of a single-atom iron catalyst (Fe©SiO2) for the direct conversion of methane to olefins, aromatics, and hydrogen is a breakthrough in the field of nonoxidative conversion of methane (NCM). However, the optimization of the catalyst remains desirable for industrial applications. Herein, 25 transition metals, including Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Hf, Ta, W, Re, Os, Ir, Pt, and Au, are selected to replace the central Fe atom for screening out better single-atom catalysts for the NCM. Using the performance on the activation of methane, such as the adsorption energy of methane, the dissociation energy, and the barrier of methane as the screening descriptors, Mn©SiO2, Fe©SiO2, W©SiO2, and Re©SiO2 are first screened out. The remarkable performance of the four catalysts on methane activation is attributed to the unique geometric structure and the d z 2 orbitals of the central metal crossing over the Fermi level, which can benefit the interaction between methane and the catalysts. By considering the catalytic performance on the whole pathway of methane to ethylene, W©SiO2 is finally selected as the most active catalyst for the NCM, which has the lowest rate-determining barrier of 1.62 eV and the smallest free energy span (1.06 eV) of the overall catalytic cycle. [ABSTRACT FROM AUTHOR]

Focuses on a study which analyzed high-field hole transport in strained silicon-germanium alloys using a Monte Carlo technique. Description of a bond orbital model; Calculation of the valence-band structure in the simulation; Computation of the steady-state hole drift velocity and the impact ionization rate; Comparison between experimental and simulation results.

Presents a study which calculated the structural dependence of infrared absorption in p-type strained layer silicon germanium/silicon quantum wells. Physical models; Results and discussion.

Provides information on a study that calculated hole mobility in strained Si[sub1-x]Ge[subx]/Si(001) layers as functions of temperature and doping concentrations for various germanium contents using a Monte Carlo technique. Description on the Monte Carlo model; Results and discussion on the study.

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.

Reports on the experimental results of a bidirectional bistability switching device using gallium arsenide double triangular barrier structures prepared by molecular beam epitaxy. Previous studies on negative differential resistance; Device growth and fabrication; Discussion on the results of the experiment.

A novel, low-cost, and simple circuit for driving a laser diode with low supply voltage was demonstrated. A laser diode was driven with a supplied voltage as low as 1.5 V using only two transistors and minimum passive components. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Ion implantation is used to create nanodiamonds (NDs) with embedded magnetic ions for use in a wide range of biological and medical applications; however, the effectiveness of this process depends heavily on separating magnetic NDs from nonmagnetic ones. In this study, we use secondary ion mass spectrometry to verify the implantation of magnetic ions in NDs and the success of separation. When applied to a series of NDs with embedded iron or manganese ions, the sorting tool used in this study proved highly effective in selecting magnetic NDs. Besides, multienergy ion implantation and precise thickness control of NDs coating on the silicon wafer were suggested to improve this technology. [ABSTRACT FROM AUTHOR]

This letter proposes an efficient parameterization of the three-dimensional room transfer function (RTF) which is robust for the position variations of source and receiver in respective horizontal planes. Based on azimuth harmonic analysis, the proposed method exploits the underlying properties of the associated Legendre functions to remove a portion of the spherical harmonic coefficients of RTF which have no contribution in the horizontal plane. This reduction leads to a flexible measuring-point structure consisting of practical concentric circular arrays to extract horizontal plane RTF coefficients. The accuracy of the above parameterization is verified through numerical simulations. [ABSTRACT FROM AUTHOR]

Actinide mononitrides as a promising advanced nuclear fuel have recently earned much attention. We herein studied the electronic and mechanical properties of the ternary actinide mixed mononitrides A0.5B0.5N (A, B=U, Np, and Pu) using the density functional theory +U method. It is found that in the studied ternary mixed mononitrides, the 5f electronic states of all actinide atoms maintain the local electronic character and do not overlap with each other. Compared with their corresponding binary mononitrides, the U-N bond becomes more ionic, where the Np-N and Pu-N bonds become more covalent in ternary actinide mixed mononitrides. The mechanical properties (such as bulk and shear moduli, Young’s modulus, and Poisson’s ratio) of three ternary actinide (U-Pu) mononitrides are found to be similar to that of their corresponding binary actinide mononitrides and thus are expected not to misbehave with actinide mononitrides in respect of mechanics. In addition, all the three ternary actinide mononitrides have no imaginary frequencies in their vibration curves and correspondingly satisfy the stability criteria for elastic constants of tetragonal structures. [ABSTRACT FROM AUTHOR]

The authors provided the formation and memory effects of nonvolatile multilayer nickel-silicide nanocrystal memory in this study. This proposed structure can efficiently improve the drawbacks of current floating gate and single-layer nanocrystal memories for the next-generation nonvolatile memory application. The charge trapping layer of multilayer structure was deposited by sputtering a commixed target (Ni0.3Si0.7) in the argon and nitrogen ambiance, and then used a low temperature rapid thermal annealing to form uniform nanocrystals. Transmission electron microscope images clearly show the multilayer and single-layer nanocrystal structures embedded in SiNx. X-ray photoelectron spectroscopy and x-ray diffraction also present the chemical states and crystallization of nanocrystals under different annealing temperature treatments. The capacitor with different memory structures was also studied and exhibited hysteresis characteristics after electrical operation. In addition, the multilayer nanocrystals revealed better charge storage ability and reliability than the single-layer nanocrystals. [ABSTRACT FROM AUTHOR]

In this study we investigated the interfacial chemistry occurring between an atomic-layer-deposited Al2O3 high-k film and a GaAs substrate and the impact of sulfidization and thermal annealing on the properties of the resultant capacitor. We observed that sulfide passivation of the Al2O3/GaAs structure improved the effect of Fermi level pinning on the electrical characteristics, thereby providing a higher oxide capacitance, smaller frequency dispersion, and reduced surface states, as well as decreased interfacial charge trapping and gate leakage currents. Photoemission analysis indicated that the (NH4)2S-treated GaAs improved the quality of the as-deposited Al2O3 thin film and preserved the stoichiometry of the dielectric during subsequent high-temperature annealing. This behavior was closely correlated to the diminution of GaAs native oxides and elemental arsenic defects and their unwanted diffusion. In addition, thermal processing under an O2 atmosphere, relative to that under N2, decreased the thickness of the Al2O3 gate dielectric and relieved the gate leakage degradation induced by metallic arsenic; as a result, superior dielectric reliability was attained. We discuss the underlying thermochemical reactions that account for these experimental observations. [ABSTRACT FROM AUTHOR]

In this study we used a low-pressure metal organic vapor phase epitaxy method to investigate the growth of GaAs metal gate semiconductor field effect transistor (MESFET) structures on a Si substrate. The buffer layer between the Si substrate and the grown GaAs epitaxial layers was a composite Ge/Si0.05Ge0.95/Si0.1Ge0.9 metamorphic layer. We used transmission electron microscopy to observe the microstructures formed in the grown GaAs/Ge/SixGe1-x/Si material and atomic force microscopy to analyze the surface morphology and the formation of antiphase domains in the GaAs epitaxial layers. The measured Hall electron mobility in the channel layer of a MESFET structure grown on a 6° misoriented Si substrate was 2015 cm2 V-1 s-1 with a carrier concentration of 5.0×1017 cm-3. The MESFET device fabricated on this sample exhibited good current-voltage characteristics. [ABSTRACT FROM AUTHOR]

We report a class of poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] copolymers synthesized via reductive dechlorination from P(VDF-CTFE) [termed as the reduced P(VDF-TrFE) copolymer], which exhibit ferroelectric relaxor behavior at high temperature (∼100 °C). It was found that the reduced P(VDF-TrFE) 66/34 mol % copolymer has very high content of head-to-head and tail-to-tail defects, which may act as random defects, leading to the observed ferroelectric relaxor at high temperature. Furthermore, the reduced copolymer also exhibits a high melting point (∼200 °C), which also makes it attractive for high-temperature dielectric applications. [ABSTRACT FROM AUTHOR]

To determine the relevance of current crowding to electromigration in the SnAg3.0Cu0.5 solder bump, a three-dimensional dual bumps simulation model was designed to demonstrate how current crowding can enhance the local atomic flux along the electron flow path. The finding of void formation occurred at the entrance points to the cathode sides and the enhancement of the growth and clustering of the intermetallic compound at the outgoing points of the anode sides along the electron flow path were verified experimentally. The tilting effect is obvious at the anode/chip side. The experimental mean-time-to-failure was observed, and Black’s equation with Joule heating effect were investigated as well. [ABSTRACT FROM AUTHOR]

A correction is noted to the online edition of the article “Investigation statistics of bipolar multilevel memristive mechanism and characterizations in a thin FeOx transition layer of TiN/SiO2/FeOx/Fe structure” which was first published on September 1, 2011.

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.

Presents a study which investigated the Schottky contacts on Ga[sub0.51]In[0.49]P epitaxial layer. Methodology used to determine the barrier heights of the Schottky diodes; Current-voltage characteristics of the Schottky diodes; Results of the study.

Focuses on a study which observed the growth and electrical characterization of silicon delta-doped GaInP grown by metalorganic chemical vapor deposition. Experimental details; Results and discussion; Conclusion.

The small-sized herringbone groove journal bearing (HGJB), i.e., so-called “magnetic bearing,” filled with Newtonian ferrofluid lubrication is investigated via finite difference analysis (FDA), with consideration of cavitation zones in HGJB. The FDA starts with constructing the mass flux equations of the HGJB filled with ferrofluid. Discretization for FDA is next performed over the bearing clearance domain, from which algebraic finite difference equations based on the mass flow balance over the clearance domain are derived. Solving the equations, rotordynamic coefficients, cavitation zones, and side leakage rate are successfully predicted to show effectiveness in enhancing bearing performance by ferrofluid. [ABSTRACT FROM AUTHOR]

This study demonstrates a room-temperature ultraviolet GaN/Al nanorod (NR) metal laser with an optimized sidewall. A wet-chemical etching process with potassium hydroxide was used to control the GaN NR sidewall angle and polish the NR surface. The lasing action was observed near a wavelength of 365 nm with a low threshold power density of 5.2 mJ/cm2. The high-quality factor (Q) surface plasmon lasing modes were characterized with experiments and three-dimensional finite-element method simulations. We also studied the optical modes in GaN metal-coated NR with and without an Al layer and verified the metal layer is necessary for high-Q resonant modes. [ABSTRACT FROM AUTHOR]

A low-cost and simple circuit for driving blue light emitting diodes with ultralow supply voltage is demonstrated. By using only three transistors and two voltage multipliers, a blue light emitting diode was driven with a supplied voltage as low as 0.8 V. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A current mode Schmitt trigger for a phototransistor/resistor detector is presented. It can be successfully operated with a 1.5 V power supply. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

A low-cost and simple circuit for driving light-emitting diodes with low supply voltage was demonstrated. By using only three transistors, a light emitting diode was drived with supplied voltage as low as 0.85 voltage. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The breakdown voltage (VBD) and breakdown mechanism of junctionless (JL) poly-Si thin film transistor (TFT) were compared to the conventional inversion-mode (IM) TFT using fabricated devices and 3D quantum-corrected hydrodynamic transport device simulation. The simulated results are correspondent with experimental ones. The analyses of electric field distributions in on-state show that the channel of JL devices can equally share the voltage like a resistor, because there are no junctions formed between channel and source/drain. The JL TFT shows excellent breakdown characteristics; the off-state VBD of 53.4 V is several times larger than VBD of 9.5 V in IM TFT with same device size. JL devices have large potential for high voltage power metal-oxide-semiconductor devices and circuit applications. [ABSTRACT FROM AUTHOR]

The formation of Ni–Si and Ni–N nanocrystals by sputtering a Ni0.3Si0.7 target in argon and nitrogen environment were proposed in this paper. A transmission electron microscope analysis shows the nanocrystals embedded in the nitride layer. X-ray photoelectron spectroscopy and x-ray diffraction also offer the chemical material analysis of nanocrystals with surrounding dielectric and the crystallization of nanocrystals for different thermal annealing treatments. Nonvolatile Ni–Si nanocrystal memories reveal superior electrical characteristics for charge storage capacity and reliability due to the improvement of thermal annealing treatment. In addition, we used energy band diagrams to explain the significance of surrounding dielectric for reliability. [ABSTRACT FROM AUTHOR]

This study reveals the formation of nickel-oxygen-silicon nanoparticles with nonvolatile memory effect by sputtering a commixed target in argon and oxygen ambiance. A transmission electron microscope clearly shows the embedded nanoparticles in the silicon oxide and the constituent was examined by x-ray photoelectron spectroscopy. The capacitor structure with embedded nickel-oxygen-silicon nanoparticles was also studied and it exhibited hysteresis characteristics after electrical operation. The memory window and retention of nickel-oxygen-silicon nanoparticles were enough to apply on nonvolatile memory. In addition, a physical mechanism was deduced to expound the role of oxygen in the formation of nickel-oxygen-silicon nanoparticles. [ABSTRACT FROM AUTHOR]

In this work, we studied a pi-shape gate polycrystalline silicon thin-film transistor (poly-Si TFT) with silicon-oxide-nitride-oxide-silicon (SONOS) layers and nanowire channels for the application of electric driver and nonvolatile memory. The proposed pi-gate TFT-SONOS has superior transfer characteristics and its output characteristic also exhibits the high driving current and the suppression of the kink effect. For memory application, the device can provide high program/erase efficiency and large threshold voltage shift under adequate bias operation. The enhanced performance for the pi-gate TFT-SONOS is attributed to the larger effective channel width and the number of channel corners. [ABSTRACT FROM AUTHOR]

A silicon-oxide-nitride-oxide-silicon type polycrystalline silicon thin-film transistor (poly-Si TFT) with nanowire channels was investigated for both transistor and memory applications. The poly-Si TFT memory device has superior electrical characteristics, such as higher drain current, smaller threshold voltage, and steeper subthreshold slope. Also, the simulation result on electrical field reveals that the electrical field across the tunnel oxide is enhanced and that across the blocking oxide is reduced at the corner regions. This will lead to the parasitic gate injection activity and the erasing speed can be apparently improved in the memory device due to the pronounced corner effect and narrow channel width. [ABSTRACT FROM AUTHOR]

The authors proposed a formation mechanism of Ge nanocrystals embedded in the dielectric by using Si1.33Ge0.67O2 and Si2.67Ge1.33N2 films for nonvolatile memory application in this study. Because of internal competition reaction, this formation process reduced the thermal budget and eliminated the use of high pressure H2 treatment or steam process. In this research, the preannealing capping oxide step is a critical process for nonvolatile memory effect. Transmission electron microscope shows the shape and density of nanocrystals in the dielectric. Moreover, the memory structure with Ge nanocrystal embedded in SiNx has better charge storage ability and data retention than Ge nanocrystal embedded in SiOx. [ABSTRACT FROM AUTHOR]

The formation of nickel-silicon-nitride nanocrystals by sputtering a comixed target in the argon and nitrogen environment is proposed in this letter. High resolution transmission electron microscope analysis clearly shows the nanocrystals embedded in the silicon nitride and x-ray photoelectron spectroscopy also shows the chemical material analysis of nanocrystals. The memory window of nickel-silicon-nitride nanocrystals enough to define 1 and 0 states is obviously observed, and a good data retention characteristic to get up to 10 years is exhibited for the nonvolatile memory application. [ABSTRACT FROM AUTHOR]

In this work, the authors study a polycrystalline silicon thin-film transistor (poly-Si TFT) with oxide/nitride/oxide (ONO) stack gate dielectrics and multiple nanowire channels for the applications of both nonvolatile silicon-oxide-nitride-oxide-silicon (SONOS) memory and switch transistor. The proposed device named as nanowire SONOS-TFT has superior electrical characteristics of a transistor such as on/off current ratio, threshold voltage (Vth), and subthreshold slope due to the good gate control ability originated from fringing electrical field effects. Moreover, the proposed device under adequate operation scheme can exhibit high program/erase efficiency and good retention time characteristics at high temperature. [ABSTRACT FROM AUTHOR]