An efficient optical power splitter constructed by a metal-dielectric-metal plasmonic waveguide with a resonator structure has been analyzed. The method of solution is the finite difference time domain (FD-TD) method with the piecewise linear recursive convolution (PLRC) method. The resonator structure consists of input/output waveguides and a narrow waveguide with a T-junction. The power splitter with the resonator structure is expressed by an equivalent transmission-line circuit. We can find that the transmittance and reflectance calculated by the FD-TD method and the equivalent circuit are matched when the difference in width between the input/output waveguides and the narrow waveguide is small. It is also shown that the transmission wavelength can be adjusted by changing the narrow waveguide lengths that satisfy the impedance matching condition in the equivalent circuit.

The generation and reduction reaction of magnesium plasma were studied using a cylindrical transverse magnetic-mode applicator in magnetic and electric field modes. By heating Mg powder using the magnetic field mode, plasma was generated with the evaporation of Mg and stably sustained. When the Mg plasma sample was introduced into the reaction zone and exposed to microwave and lamp heating, a reduction reaction of scandium oxide also occurred. The results of this study provide prospects for the development of a larger microwave refining system.

In this research, we investigated the threshold voltage (VTH) control by partial polarization of metal-ferroelectric-semiconductor field-effect transistors (MFSFETs) with 5 nm-thick nondoped HfO2 gate insulator utilizing Kr-plasma sputtering for Pt gate electrode deposition. The remnant polarization (2Pr) of 7.2 μC/cm2 was realized by Kr-plasma sputtering for Pt gate electrode deposition. The memory window (MW) of 0.58 V was realized by the pulse amplitude and width of -5/5 V, 100 ms. Furthermore, the VTH of MFSFET was controllable by program/erase (P/E) input pulse even with the pulse width below 100 ns which may be caused by the reduction of leakage current with decreasing plasma damage.

An efficient bent waveguide and an optical power splitter with a resonator constructed by a metal-dielectric-metal plasmonic waveguide have been analyzed. The method of solution is the finite difference time domain (FD-TD) method with the piecewise linear recursive convolution (PLRC) method. The resonator can be realized by utilizing impedance mismatch at the connection between a narrow waveguide and an input/output waveguide. Numerical results for the bent waveguide show that transmission bands can be controlled by adjusting the length of the narrow waveguide. We have also shown that the optical power of the power splitter is entirely distributed into the output waveguide at the resonant wavelength and its distribution ratio can be controlled.

Low-temperature deposition of Y2O3 at 80°C is studied using an yttrium precursor of tris(butylcyclopentadienyl)yttrium (Y(BuCp)3) and plasma exited humidified argon oxidizer. The deposition is demonstrated using an atomic-layer-deposition sequence; the Y(BuCp)3 and the oxidizing gases are time separately introduced to the reaction chamber and these injections are repeated. To determine the gas introduction conditions, surface reactions of Y(BuCp)3 adsorption and its oxidization are observed by an in-situ IR absorption spectroscopy. The deposited film is confirmed as fully oxidized Y2O3 by X-ray photoelectron spectroscopy. The present deposition is applicable for the deposition of Y2O3 film on flexible polyethylene terephthalate films.

The low temperature deposition of AlN at 160 °C is examined by using trimethyl aluminum (TMA) and NH radicals from plasma excited Ar diluted ammonia. For the deposition, a plasma tube separated from the reaction chamber is used to introduce the neutral NH radicals on the growing surface without the direct impacts of high-speed species and UV photons, which might be effective in suppressing the plasma damage to the sample surfaces. To maximize the NH radical generation, the NH3 and Ar mixing ratio is optimized by plasma optical emission spectroscopy. To determine the saturated condition of TMA and NH radical irradiations, an in-situ surface observation of IR absorption spectroscopy (IRAS) with a multiple internal reflection geometry is utilized. The low temperature AlN deposition is performed with the TMA and NH radical exposures whose conditions are determined by the IRAS experiment. The spectroscopic ellipsometry indicates the all-round surface deposition in which the growth per cycles measured from front and backside surfaces of the Si sample are of the same range from 0.39∼0.41nm/cycle. It is confirmed that the deposited film contains impurities of C, O, N although we discuss the method to decrease them. X-ray diffraction suggests the AlN polycrystal deposition with crystal phases of AlN (100), (002) and (101). From the saturation curves of TMA adsorption and its nitridation, their chemical reactions are discussed in this paper. In the present paper, we discuss the possibility of the low temperature AlN deposition.

We fabricated Fe-silicide nanodots (NDs) on an ultrathin SiO2 layer and evaluated changes in electron transport properties with and without magnetic field application. High-density NDs with an areal density as high as ∼1011cm-2 were formed on thermally grown SiO2 by exposing ultrathin Fe/Si-NDs structures to a remote H2 plasma without external heating. In electron transport properties related to current-time characteristics for a diode with Fe electrode and charging energy to NDs, clear changes in current levels through NDs and electron injection modulation of NDs depending on intensity of magnetic fields were observed.

A periodic array of InSb spheres on a substrate is numerically analyzed at terahertz frequencies. The incident field is shown to be coupled to the substrate due to the guided-mode resonance. The effect of the background refractive index on the transmission characteristics is investigated for sensor applications.

A grating consisting of a periodic array of InSb-coated dielectric cylinders on a substrate is analyzed at THz frequencies using the frequency-dependent finite-difference time-domain method based on the trapezoidal recursive convolution technique. The transmission characteristics of an infinite periodic array are investigated not only at normal incidence but also at oblique incidence. The incident field is shown to be coupled to the substrate due to the guided-mode resonance (GMR), indicating the practical application of a grating coupler. For the sensor application, the frequency shift of the transmission dip is investigated with attention to the variation of the background refractive index. It is found that the shift of the dip involving the surface plasmon resonance is almost ten times as large as that of the dip only from the GMR. We finally analyze a finite periodic array of the cylinders. The field radiation from the array is discussed, when the field propagates through the substrate. It is shown that the radiation direction can be controlled with the frequency of the propagating field.

We have investigated the in-situ N2-plasma nitridation for high-k HfN gate insulator formed by electron cyclotron resonance (ECR) plasma sputtering to improve the electrical characteristics. It was found that the increase of nitridation gas pressure for the deposited HfN1.1 gate insulator, such as 98 mPa, decreased both the hysteresis width in C-V characteristics and leakage current. Furthermore, the 2-step nitiridation process with the nitridation gas pressure of 26 mPa followed by the nitridation at 98 mPa realized the decrease of equivalent oxide thickness (EOT) to 0.9 nm with decreasing the hysteresis width and leakage current. The fabricated metal-insulator-semiconductor field-effect transistor (MISFET) with 2-step nitridation showed a steep subthreshold swing of 87 mV/dec.

Photophysical properties of water-soluble porphyrin were studied in aqueous solutions with/without DNA and in DNA solid films. Ultrathin films were prepared from aqueous DNA solutions by a spin-coating method on glass or on gold nanoparticles (AuNPs). Remarkable enhancement of phosphorescence was observed for porphyrin immobilized in DNA films spin-coated on AuNPs, which was attributed to the electric field enhancement and the increased radiative rate by localized surface plasmon resonance of AuNPs.

In this work, we report the in situ growth of gold nanoparticles (AuNPs) for the improvement of a transmission surface plasmon resonance (T-SPR) sensor to detect human immunoglobulin G (IgG). Human IgG was immobilized on an activated self-assembled monolayer of 11-mercaptoundecanoic on a gold-coated grating substrate. The T-SPR system was also used to monitor the construction of sensor chips as well as the binding of IgG and anti-IgG conjugated with AuNPs. After specific adsorption with IgG, the T-SPR signal was further enhanced by the in situ growth of AuNPs bound with anti-IgG. Using AuNP conjugation and in situ growth of bound AuNPs, the sensitivity of the IgG immunosensor was improved by two orders of magnitude compared with that without conjugated AuNPs.

The locally one-dimensional finite-difference time-domain (FDTD) method in cylindrical coordinates is extended to a frequency-dependent version. The fundamental scheme is utilized to perform matrix-operator-free formulations in the right-hand sides. For the analysis of surface plasmon polaritons propagating along a plasmonic grating, the computation time is significantly reduced to less than 10%, compared with the explicit cylindrical FDTD method.

A plasmonic black pole (PBP) consisting of a series of touching spherical metal surfaces is analyzed using the finite-difference time-domain (FDTD) method with the periodic boundary condition. First, the wavelength characteristics of the PBP are studied under the assumption that the PBP is omnidirectionally illuminated. It is found that partial truncation of each metal sphere reduces the reflectivity over a wide wavelength range. Next, we consider the case where the PBP is illuminated with a cylindrical wave from a specific direction. It is shown that an absorptivity of more than 80% is obtained over a wavelength range of λ=500 nm to 1000 nm. Calculation regarding the Poynting vector distribution also shows that the incident wave is bent and absorbed towards the center axis of the PBP.

In this study, the effect of atomically flat Si(100) surface on Hf-based Metal-Oxide-Nitride-Oxide-Silicon (MONOS) structure was investigated. After the atomically flat Si(100) surface formation by annealing at 1050/60min in Ar/4%H2 ambient, HfO2(O)/HfN1.0(N)/HfO2(O) structure with thickness of 10/3/2nm, respectively, was in-situ deposited by electron cyclotron resonance (ECR) plasma sputtering. The memory window (MW) of Al/HfO2/HfN1.0/HfO2/p-Si(100) diodes was increased from 1.0V to 2.5V by flattening of Si(100) surface. The program and erase (P/E) voltage/time were set as 10V/5s and -8V/5s, respectively. Furthermore, it was found that the gate current density after the 103P/E cycles was decreased one order of magnitude by flattening of Si(100) surface in Ar/4.0%H2 ambient.

In this study, a plasma loop tube is presented as a tunable VHF-UHF band plasma antenna. In plasma medium, wave radiation mechanism is due to ionized gas instead of metal. Meanwhile, the most important advantage of plasma elements is electronic tunability rather than the rigid and fixed features of metals. Here, we employ an external magnetic field as a background to affect the plasma without any shape, gas or source manipulation. Finite difference time domain (FDTD) is performed for plasma antenna analysis. The FDTD formulation should be adapted to fluid modeling of plasma in the anisotropic zone in the presence of an external magnetic field. The bandwidth coverage of 700MHz is obtained by designing correctly. Parametric study in return loss, gain and radiation pattern are studied here and other new points are presented as well.

A plasma lighting system (PLS) using a solid-state (SS) radio frequency (RF) power amplifier (PA) is one of the promising lighting systems due to its excellent light characteristics and power efficiency. To improve the efficacy and reduce the adjacent channel interference of the PLS, a method to generate a band-limited pulsed-RF signal using the limited number of multi-tone signals is proposed. A 2.49 GHz PLS with a 300W gallium-nitride (GaN) SSPA is implemented, and it is used to verify the proposed method. The PLS using the proposed method shows better performance compared with those using conventional pulsed-RF signal.

This paper proposes an address power reduction method for plasma display panels (PDPs) using subfield data smoothing based on a visual masking effect. High-resolution, high-frame-rate PDPs have large address power loss caused by parasitic capacitance. Although the address power is reduced by smoothing the subfield data, noise is generated. The proposed method reduces the address power while maintaining the image quality by choosing the smoothing area of the address data based on the visual masking effect. The results of subjective assessment for the images based on smoothed address data indicate that image quality is maintained.

Two plasmonic band-bass filters are analyzed: one is a grating-type filter and the other is a slit-type filter. The former shows a band-pass characteristic with a high transmission for a two-dimensional structure, while the latter exhibits a high transmission even for a three-dimensional structure with a thin metal layer.

The optical properties of arrays of nanoholes and nanoslits in Al films were investigated both numerically and experimentally. The choice of Al was based on its low cost and ease of processing, in addition to the fact that it has a higher plasma frequency than gold or silver, leading to lower optical losses at wavelengths of 400 to 500nm.