In this work, electron beam lithography proximity effect correction (PEC) was experimentally studied for patterning of Si photonic waveguides with a relatively thick resist mask. Beam’s energy density distribution (EDD) was experimentally extracted by the line exposure method; however, exposure lines in this work were developed after cleavage with a high-contrast process to reduce developer-related

Using non-equilibrium Green’s function (NEGF) combined with the density functional theory (DFT) first-principles method, we perform a theoretical study for oligomeric phenylene ethynylenes (OPE) molecule sandwiched between different C 2 N- h 2D nanoribbon electrodes. The results point to the conclusion that the electronic transport properties of the devices depend greatly on the edge and width of the

We have introduced a correlating synthesis (CS) method for high-resolution terahertz (THz) imaging. The efficiency of the CS method was verified by imaging experiment of metal cylinders using a pulse reflection mode terahertz time-domain-spectrometry system. In this paper, we study the influence of layered dielectric in the propagation path of THz wave. A method of propagation time correction by ray

The influence of high-intensity focused ultrasound (HIFU) reflected from a soft-tissue/bone interface on the temperature rise and lesion formation was theoretically and experimentally investigated in a soft-tissue/bone phantom. The acoustic intensities and the HIFU-induced temperature rises at the focal and the pre-focal regions were numerically simulated without and with the bone. Thermal ablation

In this study, the influence of thermal budget on preparing hafnium silicate (HfSiO) and metal–insulator–semiconductor (MIS) structures with tetragonal hafnium oxide (HfO 2 ) films was investigated. Amorphous silicon (a-Si) was used as a sacrificial layer for HfSiO formation. Rapid thermal annealing (RTA) could efficiently drive the oxidation of a-Si with HfO 2 . The RTA-produced HfSiO film thicker

The interface condition between the graphene channel and aluminum oxide (Al 2 O 3 ) gate insulator in a graphene field-effect transistor (FET) has been analyzed. The hard X-ray photoelectron spectroscopy technique was employed to analyze the interface. In the obtained C1s spectra, a small peak was found at 284.2 eV, which was considered to be derived from a covalent bond between the graphene and Al

The ablation threshold fluence and crater morphology of amorphous and crystalline SiO 2 glass were analyzed in the regime of an extreme ultraviolet femtosecond pulse. Despite the difference between the densities (or optical penetration depths) of amorphous and crystalline SiO 2 glass, the ablation threshold fluences and crater morphologies were found to be comparable. In addition, we compared our experimental

We investigated the detection limit of carbon in Si for the photoluminescence (PL) method after electron irradiation. The detection limit was obtained from the intensity ratio of the G-line to the free exciton line with the G-line intensity twice as high as the noise level and was estimated at 4 × 10 13 cm −3 under the measurement condition in accordance with the standard [JIS H0615] for quantification

Highly crystalline c -axis oriented ZnO thin films with ultra-flat surfaces were fabricated by pulsed laser deposition at RT on 0.3 nm high atomically stepped cyclo-olefin polymer (COP) substrates whose surfaces were thermally nanoimprinted using atomically stepped sapphire molds. X-ray diffraction and atomic force microscopy measurements showed that the atomically-controlled surfaces of COP substrates

In magnetic field confinement plasma devices such as the International Thermonuclear Experimental Reactor (ITER), hydrogen atoms and molecules are emitted from plasma-facing materials by hydrogen recycling. The effect of the recycled hydrogen in edge plasma can be investigated by neutral transport analysis. In this paper, in order to obtain the boundary condition at the tungsten divertor for neutral

Operando detection of various physical quantities in electronic devices under operation has been demonstrated by optically detected magnetic resonance (ODMR) using nitrogen vacancy (NV) centers in diamond. However, the ODMR spectrum may also be affected by the existence of the metal electrodes and wirings of the electronic device, which limits the accurate measurement of the objective physical quantity

The effect of hydrogen on Pt/GaN Schottky diodes was studied using current–voltage ( I – V ), capacitance–voltage ( C – V ), and impedance spectroscopy measurements. The results showed that hydrogen exposure reduced the Schottky barrier height and the resistance of the semiconductor space-charge region but did not affect the ideality factor, carrier concentration, or capacitance of the semiconductor

First-principles molecular dynamics (FPMD) simulation is a powerful tool for studying the mechanical, chemical, and thermal properties of materials. However, because of the fundamental time-scale limitation of molecular dynamics and the high computational cost of density functional theory, many of the rare events that dominate these properties cannot be directly investigated. Several methods of accelerating

Recent developments in sources of low-temperature atmospheric plasma have expanded their applications in medicine, leading to the establishment of the field of “plasma medicine”. In the first half of this paper, the clinical studies conducted to date on wound treatments using low-temperature atmospheric plasmas are summarized. In the second half, several issues in plasma medicine are discussed from

Dislocations and their arrays in a {010}-oriented β -Ga 2 O 3 substrate were observed using synchrotron X-ray diffraction (XRD) and X-ray topography (XRT). The XRD measurements used spatially-resolved ω -rocking curves to show that dislocation arrays have a linear contrast with a lower diffraction intensity and a broader full-width at half maximum. Further XRT observations at three different ##IMG##

In this paper, we investigate the fabrication of graphene oxide (GO) films on copper substrates by means of an electrophoretic technique, with the aim of realizing conductive thin films that could be applied as reliable electrical contacts for use in various applications. Uniform films were fabricated, and the film thickness measured using atomic force microscopy. The graphene oxide film thickness

This paper demonstrates a 1 V pp low-driving-voltage silicon electro-absorption modulator (EAM) utilizing a Schottky diode. Optical modulation using a Schottky diode was achieved through the intensity change of the guiding light due to free-carrier absorption in the semiconductor to change its absorption coefficient, not through conventional interference effects. The proposed EAM consists of a lateral

The optical constants and bandgap energy ( E g ) of semiconductors, characterized by spectroscopic ellipsometry (SE), are highly affected by the applied model dielectric function (MDF). In this study, we investigated the optical constants and E g in low indium content ( x ) Al 1- x In x N alloys grown on a c -plane freestanding GaN substrate by using SE, and their applied MDF dependence was investigated

The reduction in the density of SiO 2 /Si interface state ( D it ) in the isolation region and transfer transistor gate oxide is necessary to improve the performance of complementary metal-oxide semiconductor (CMOS) image sensors. In this study, we demonstrated that a hydrocarbon-molecular-ion-implanted epitaxial silicon wafer can reduce the D it and Pb 0 center density in SiO 2 /Si interface regions

In the author’s last paper [Ikeda, Appl. Phys. Express 13 , 015508 (2020)], it was suggested that the number of molecules that constitute a critical nucleus of pentacene is about ten based on the results of molecular dynamics (MD) simulations performed to investigate the stability of clusters comprising standing pentacene molecules on substrate surfaces. In this study, the author carried out additional

We demonstrate control of all the three transitions among the ground state sublevels of NV centers by applying magnetic driving fields. To address the states of a specific NV axis among the four axes, we apply a magnetic field orthogonal to the NV axis. We control two transitions by microwave pulses and the remaining transition by radio frequency (RF) pulses. In particular, we investigate the dependence

In order to clarify the principle of oscillation in a two-phase fluid thermoacoustic engine, energy generation in a moisturized stack is theoretically investigated. Theoretical equations to express the energy generation are derived first using Raspet’s theory. The validity of derived equations was suggested by comparing the calculated value and the measured value. Furthermore, on the basis of derived

We report on the pulsed laser-induced dewetting (LID) process of Co/sapphire(0001) thin films in water environment. In contrast to LID in a vacuum, where only Co nanoparticles (NPs) are formed, a 12 nm thick Co film was dewetted into a mixture of crystalline CoO NPs and nanowalls (NWs). The formation of the CoO NPs can be explained by the grooving model occurring concurrent with the oxidation of Co

Reactive oxygen species (ROS) supplied into liquids by plasma irradiation must be identified and controlled for the safe and effective use of plasmas in biomedical applications. This study aims to obtain information on the key ROS regarding ROS transportation through a liquid layer for realization of spatial ROS identification. Two-dimensional distributions of ROS after passing through liquids with

Chemically amplified resists have been used in the state-of-the-art extreme ultraviolet (EUV) lithography. A basic additive has been added to the resist formula as a quencher to control acid diffusion. In this study, the effects of photodecomposable quencher (PDQ) concentration on the chemical gradient (an indicator of line edge roughness) in chemically amplified EUV resist processes were investigated

Hematite iron oxide (Fe 2 O 3 ), which is an n-type semiconductor with a bandgap of 2.0 ∼ 2.2 eV, is harmless to humans and extremely abundant on the Earth. In this work, Cu-doped p-type iron oxide thin films were fabricated by two-step pulse electrochemical deposition (ECD) from aqueous solutions containing FeSO 4 and CuSO 4 . Composition uniformity was improved, and surface roughness was reduced

The Ce-substituted (Ce x , Pr 1- x ) 2 Si 2 O 7 bulk single crystals were synthesized by the floating zone method, and their photoluminescence (PL) and scintillation properties were evaluated. The X-ray diffraction patterns showed that all the synthesized samples were a single-phase of monoclinic Pr 2 Si 2 O 7 . In PL and scintillation, an emission peak was observed at around 370–390 nm due to the

Ultra-fine bubbles (UFBs) have been used in successful applications in a wide variety of fields, such as healthcare, agriculture, fisheries, food engineering, and chemical engineering. In this study, we investigated the nucleation rate of protein crystals in the presence of UFBs. It was found that UFBs induced the nucleation of trypsin and lysozyme basic proteins and reduced that of glucose isomerase

This study investigates the effect of corrosion of the metallization containing lead tellurite glass frit used in solar cells due to acetic acid. When the c-Si photovoltaic (PV) module is operating in the new degradation mode, the electroluminescence (EL) dark area showed an increase in the series resistance that spreads around the bus bars. To understand metallization corrosion, a high-temperature

We report on the relationship between carrier lifetime degradation of floating-zone silicon (FZ Si) and the guard ring formation process for silicon integrated gate bipolar transistor (Si-IGBT). A clear carrier lifetime degradation was observed through the guard ring oxidation and annealing processes for Si-IGBT and showed interstitial oxygen (O i ) concentration dependence, which was obtained by Fourier

Yttrium aluminum perovskite (YAP), or YAlO 3 , shows promising potential as an up-conversion (UC) host material due to its excellent fluorescence properties and relatively lower phonon energy as compared to those of the other complex-oxide host materials. Herein, YAlO 3 was synthesized using the convenient co-precipitation technique, and single-phase YAP powder was successfully developed; it was characterized

Positron annihilation lifetime measurements were performed on polyethylene films [low-density polyethylene and ultra-high molecular weight polyethylene (UHMWPE)] with a thickness of15–2000 μ m using a Na-22 positron source enclosed in a Kapton film. For thin films, some positrons will pass through the film and annihilate behind it. Using a single film in a commercial anti-coincidence system, by placing

The uniformity of polycrystalline silicon (poly-Si) thin-film transistors (TFTs) over a large scale is an important element in their application. Characteristics of poly-Si thin films are the key factors influencing the performance of TFTs. In this area, we developed void-free (100)-surface oriented poly-Si thin films over large areas using multiline beam continuous-wave laser lateral crystallization

We aimed to improve the calculation accuracy by focusing on the neutral radical Ar * and electron density in a dual-frequency excited Ar plasma. The neutral radical Ar * has a long lifetime and becomes exhausted without actually disappearing. The coupled calculation of plasma and gas flow simulation was performed, and confirmed that Ar * in the coupled calculation spreads around, which was not shown

Polydimethylsiloxane microfluidic devices have become standard tools in cell engineering research. However, through-holes where cells access the microchannels are usually fabricated manually using biopsy punches, making it difficult to create a large array of sub-mm sized through-holes. Here, we present a fabrication process for a thin-film microfluidic device containing an array of through-holes,

Electrical properties of the wafer bonding p-GaAs/n-GaN, p-GaAs/n-Si and p-GaAs/ITO//ITO/n-Si are investigated systematically by scanning Kelvin probe force microscopy (KPFM), capacitance–voltage ( C – V ) and current–voltage ( I – V ) measurements. By using KPFM, the contact potential distributions and contact barrier differences of these bonding heterojunctions with Schottky-like characteristics

A copper film with the well arrays structure is prepared by magnetron sputtering in an anodic aluminum oxide (AAO) template. The ultraviolet–visible absorption spectra indicate that the light absorbance of the film is as high as 99.6% in the wavelength range of 200–2500 nm. The copper nanowell-array film exhibits a strong absorptance at the spectral range of 200–2500 nm owing to light trapped in the

We investigated the influence of the deposition rate on structural and magnetic properties of inverse-spinel ferrimagnet NiCo 2 O 4 epitaxial films grown by pulsed laser deposition. While films’ lattice constants are insensitive to the deposition rate, saturation magnetization, and perpendicular magnetic anisotropy for the film grown with a high deposition rate are reduced. These results imply that

ZnO and MgZnO nanowires were grown by mist chemical vapor deposition at a high growth temperature of approximately 950 °C–960 °C on a c -plane GaN layer sputtered with a thin Au layer with a designed thickness of 3 nm. The longitudinal axis growth of the ZnO nanowires was strongly enhanced, and some of the nanowires grown for 30 min were longer than6 μ m. Photoluminescence UV peaks were clearly observed

N-type bifacial interdigitated-back-contact (IBC) crystalline silicon solar cells were processed with screen-printed electrodes. The bifacial IBC cells resulted in a drastic decrease of the electrical shading loss at the finger region with decreasing pitch on the rear side. This loss was dominated by the width of the base region. In addition, passivation properties also affected carrier recombination

Ta-N thin films were prepared on glass and Al 2 O 3 substrates using high-power impulse reactive magnetron sputtering. A Ta target was used and sputtered using Ar/N 2 two gasses mixture. The phase structures, microstructures and electrical properties of Ta-N thin film with different powers and annealing temperatures were investigated. The results showed that an amorphous structure existed in the as-deposited

A novel optical waveguide sensor utilizing surface plasmon resonance (SPR) that enables the measurement of optical absorption and the thickness of a thin film was proposed. A BK-7 glass slide was used as a waveguide core, and an Ag/Au film of 5 mm width and transparent polymethyl methacrylate-co-methacrylic acid (PMMA-co-PMAA) were consecutively deposited to develop the sensor. The PMMA-co-PMAA film

Energy harvesting technology is attracting attention as “enabling technology” that expands the use and opportunities of IoT utilization, enriches lives and enhances social resilience. This technology harvests energy that dissipates around us, in the form of electromagnetic waves, heat, vibration, etc. and converts it into easy-to-use electric energy. This paper describes the features of these technologies

Surface sterilization using LF-microwave hybrid plasma, which is a low-frequency (LF) plasma jet assisted by a microwave discharge, was investigated. Hybrid plasma is an atmospheric pressure non-thermal plasma and has a large number of reactive species. To improve the performance of surface sterilization using LF-microwave hybrid plasma, two types of discharge gas supply systems were employed. The

Thermoelectric (TE) materials can convert any kind of heat into electricity through the Seebeck effect. Harvesting body heat and generating electricity by TE wearable devices can provide a convenient charge service for electrical equipment, even in the case of emergency or disaster. As a high-temperature excellent TE material, silicon also exhibits promising room temperature (RT) potential for wearable

In this paper, a two-dimensional (2D) kinetic modeling on the ion extraction process in a decaying barium plasma with a Π-type electrode configuration is performed using an open-source particle-in-cell computer code, WARP. An important phenomenon predicted by the 2D simulation is that the electric potential at the plasma bulk is lower than that of the anode after the transient sheath forms. This is

Thermochromic VO 2 thin films are fabricated by using high power impulse magnetron sputtering at room temperature. In order to increase the crystallinity and transparency of VO 2 thin films, a barrier layer of TiO 2 is deposited on the glass substrate. Then TiO 2 /VO 2 stacks are post-annealed at a temperature of 500 °C for 3 min. The transmittance properties as functions of TiO 2 and VO 2 thicknesses

Hollow copper(I) oxide (Cu 2 O) nanoparticles (NPs) with a diameter of 7.0 ± 1.3 nm were synthesized by sputter deposition of Cu in a room-temperature ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4), followed by the oxidation of Cu NPs in EMI-BF4 by prompt heating at 373 K in air. The void space was 2.3 ± 0.7 nm in size, and the shell thickness was estimated to be 2.4 nm. The

We performed a size-controlled synthesis of Pd nanoparticles (NPs) by changing the initial concentration of Pd in a solution. The correlation between the hydrogen absorption isotherm (denoted as pressure–composition–temperature (PCT)) and the Pd particle size was examined by focusing on sizes between 5 and 10 nm in diameter. The PCT curves confirmed the characteristics of Pd NPs less than 10 nm in

We have studied the energy band diagram for the Si surface and SiO 2 /Si system by using ultraviolet photoelectron spectroscopy (UPS) measurements. In the UPS measurements, monochromatized vacuum ultraviolet with variable incident photon energies below 10.50 eV was used in order to increase the detection limit of the depth from the surface and to understand the electronic states not only at the surface

A normally-off hybrid-gate p-GaN high-electron-mobility transistor (HEMT) is presented in this paper. The gate region is designed as a parallel connection between the Schottky-gate and the metal–insulator–semiconductor gate by inserting a dielectric layer under part of the gate metal. Compared to the conventional Schottky-gate p-GaN HEMT, the fabricated hybrid-gate p-GaN HEMT showed a higher threshold

The development of a full-color micro-display at the Industrial Technology Research Institute (ITRI) was reviewed in this study. The blue micro-display with 960 × 540 pixel arrays and 1984 PPI resolution is demonstrated on a CMOS active matrix addressing circuit. Different methods of fabricating such a micro-panel are developed to overcome the limitation in mass transfer. For the device size ranging

The establishment of economical and eco-friendly technologies for water treatment is a crucial issue for the realization of a sustainable society. Plasma-based treatments are promising methods for the decomposition of persistent organic compounds. This progress report summarizes recent improvements to plasma-based water treatment technologies by focusing on two types of contaminated solutions: solutions

The stress distribution of the two-dimensional (2D) horseshoe-shaped interconnect in the flexible electronic composite film under thermal load is reported, and the effect of substrate nano-SiO 2 hybridization on this stress distribution is studied. Experimental results show that when the temperature rises, stress concentration gradually occurs at the edge of the 2D horseshoe-shaped interconnect. After

Nanostructure emitters are an alternative low-power approach to generate electrons and provide control of the electron energy, digital control, and a small device size compared to that of conventional thermal emitters. Carbon nanotubes (CNTs) have been intensively investigated and reported to have excellent properties due to their high aspect ratio, high thermal conductivity, and chemical inertness

The aim of this research is to evaluate quantum yield (QY) values in radiophotoluminescence (RPL) centers and thermally stimulated luminescence (TSL) properties of the Ag-doped phosphate glass. After X-ray irradiation to the Ag-doped phosphate glass, a luminescence center of Ag 2+ newly appeared at 650 nm of which QY value was 17.8% when the irradiation dose was 10 Gy. It indicates a monotonic increase

Vapor phase growth of c -plane κ -Ga 2 O 3 films has been reported on various substrates such as sapphire, GaN, and AlN. However, these films are not single crystalline, but rather a mixture of nanometer-sized in-plane 120° rotational domains. We demonstrate a technique that solves the in-plane rotational domain problem. κ -Ga 2 O 3 was grown by epitaxial lateral overgrowth. A SiO x mask with a striped

The study found that homoepitaxial Na-flux GaN has a large stress at the interface, and the stress is released to a certain extent within 50 μ m in the growth direction of the Na-flux GaN. After passing through the columnar growth region, the Na-flux GaN tends to a stress-free state finally. The columnar growth mode is produced by GaN island growth, the islands nucleate and coalescence to produce tensile

Confocal differential interference contrast microscopy detected dots and line contrasts on the surface of epi-ready (0001) GaN wafers. Large and small dots consisted of pits,∼1.4 μ m in width and ∼7 nm in depth, and∼0.5 μ m in width and ∼2.7 nm in depth, respectively; the pits mainly formed on the outcrops of dislocations, with Burgers vectors ##IMG## [http://ej.iop.org/images/1347-4065/59/10/100907/jjapabbb23ieqn1

Carbon nanoparticles (CNPs) incorporated diamond-like carbon (DLC) films have been fabricated by a combination of rf sputtering and plasma chemical vapor deposition. Spherical CNPs with a mean size of 21.2 nm are sandwiched between DLC layers with a mass density of 1.7 g cm −3 . The film stress is decreased to 119 MPa, by depositing the CNPs over the base DLC layer at a surface coverage of 10.7%. This