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A combination of a gliding arc discharge and a spouted catalytic bed was used to investigate a plasma–catalytic hybrid system using CH4 reforming as a model reaction. Alumina-supported catalysts that contained 0.5 wt% of Pt, Pd, Rh, and Ru (denoted as Pt/Al2O3, Pd/Al2O3, Rh/Al2O3 and Ru/Al2O3, respectively) were used. For comparison, active Al2O3 particles were also examined. The conversion of CH4 and the selectivity of the product were investigated by changing the feed flow rate and reaction time. The production of C2H2, H2 and soot was observed in the gliding arc discharge without a catalyst. Using Pt/Al2O3 and Pd/Al2O3with the gliding arc discharge, C2H4, C2H6 and C2H2 were produced. It is considered that C2H4 and C2H6 were formed by the hydrogenation of C2H2 on the active site of Pt/Al2O3 and Pd/Al2O3. A stronger resistance to deactivation was shown in the presence of Pd/Al2O3 than in the presence of Pt/Al2O3, whereas the selectivity of hydrocarbon using Rh/Al2O3 and Ru/Al2O3 showed a tendency similar to that in active Al2O3 and non-catalytic experiments. The proposed reactor has a potential to improve the selectivity of the plasma process.

A novel absorption structure for the capacitive infrared (IR) detectors is proposed. By attaching an IR mirror under the absorber at a distance of λ/4, the resonant cavity structure is established, providing a consistent absorptance of 78% regardless of the absorber position and the device temperature.

A high power flashlamp-pumped Nd:YAG laser at 1123 nm with a repetition rate of 40 Hz is investigated. Simple but specially coated resonator mirrors are adopted to suppress the parasitic oscillation at gain transition lines higher than 1123 nm. A maximum average output power of 40 W with an electrical pumping energy of 45.7 J and pumping pulse duration of 150 µs is achieved. To the best of our knowledge, the output power of 40 W at a wavelength of 1123 nm is the highest record up to now.

Nanoscale domain growth dynamics of ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) thin films were investigated by piezoresponse force microscopy. A 90 nm thick ferroelectric polymer thin films were fabricated on Au substrate by spin-coating method. The domain size of nanoscale dot pattern was linearly proportional to logarithmic value of the pulse width. However there was a significant asymmetry in nucleation and lateral domain growth depending on the voltage polarity, which implies the existence of the preferred polarization states. The obtained activation field indicates the nucleation-limited domain switching behaviors of ferroelectric polymer thin films.

In this study, resistance fluctuation or 1/ f noise was measured in thin films of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The 1/ f noise of thin films is much larger than what is typical uncooled type microbolometer sensing material such as vanadium oxide films and amorphous silicon films. To use PEDOT:PSS thin films for a bolometric application, the 1/ f noise should be reduced. This study discusses the effect of passivation for reducing the 1/ f noise.

We report a general methodology for producing focused arrays of nanoparticles via electrodynamic focusing approach and controlling the inertial effect of charged aerosols. An important effect of particle inertia is identified and verified by performing detailed calculations of electric field induced particle motion and experimenting with electrosprayed nanoparticles. The controllability of focusing is demonstrated by changing the curvature of electric field lines.

Purpose:Congenital muscular torticollis (CMT), a common musculoskeletal disorder in infants, is characterized by the rotation and flexion deformity of the neck caused by sternocleidomastoid muscle shortening. We investigated the clinical courses and perinatal risk factors of CMT. Methods:Less than 6-month-old patients (98; M:F = 60:38) diagnosed with CMT between February 2007 and August 2008 were classified into 2 clinical subgroups, namely, SMT (sternocleidomastoid tumor) and POST (postural torticollis). All the patients were physically and neurologically examined prospectively and their cervical X-rays and ultrasonographies were obtained. Their medical histories about perinatal problems were recorded. Of the 98 patients, 45 with normal range of motion were taught passive physical exercises and 43 were referred to the Department of Rehabilitation for undergoing manual stretching therapy. Results:The mean age at initial assessment was 2.2 months (SMT: 1.41.0, POST: 2.71.6). SMT presented earlier than POST. All ophthalmologic examinations and cervical X-rays were normal. SMT was associated with higher incidence of caput succedaneum and cephalhematoma. POST was highly associated with plagiocephaly. Mean duration of rehabilitative physical therapy was 3.7 months (SMT: 4.62.5, POST: 2.61.9). POST resolved earlier than SMT. Of the 88 patients with follow-up, 87 had total resolution and only 1 had residual torticollis. Conclusion:All the patients received early treatment with passive stretching exercises. CMT was associated with perinatal problems and had various risk factors such as obstetrical problems.

In this work we demonstrated a tunable planar inverted-F antenna (PIFA) for the correction of impedance mismatch resulting from the resonant frequency shift in the usage of mobile phones due to human hand effects. The tunable PIFA has a tuning line with electrical path to the ground plate through an RF MEMS switch and loading capacitor. By changing the switch status, the resonant frequency of the PIFA can be tuned with the loading capacitance value. The characteristics of the tunable PIFA with different positions of tuning line and value of loading capacitance have been evaluated. A metal-to-metal direct-contact-type RF MEMS switch has been used for tuning the resonant frequency of the capacitor-loaded PIFA, which is piezoelectrically actuated with low actuation voltage. The insertion loss of the RF MEMS switch was measured to be −0.23 dB at 2 GHz with an applied DC bias of 2.5 V. The isolation of the switch was −42.5 dB at 2 GHz. The resonant frequency of the PIFA shifted from 842 to 762 MHz by turning the switch on. The characteristics of the tunable PIFA were measured in the presence of a phantom hand, to show the feasibility of correcting the resonant frequency shift by human hand effects. When the switch was on, the resonant frequency of the PIFA shifted from 762 to 690 MHz, and this was attributed to the phantom hand effect. Turning the switch off caused the PIFA to recover its original resonant frequency with the phantom hand. The measured resonant frequency of the PIFA with the switch off was 760 MHz with the phantom hand and the return loss at the resonant frequency was −22 dB.

Calculated chemical equations using thermodynamics suggest that elemental Te0 is easily induced during bromine-based etching process on the HgCdTe surface and the induced elemental Te0 can be removed by chemical reaction with hydrazine, forming volatile H2Te. X-ray photoelectron spectroscopy (XPS) confirmed these chemical reactions. The induced elemental Te0 is believed to play a role as surface generation-recombination centers in CdTe∕HgCdTe interface, which was confirmed by XPS, ideality factor, and energy-dispersive interface trap density (Dit) analyses.

In this letter, the effect of annealing in plasma-induced-type converted HgCdTe was observed. The Hg deficient annealing process reconverts the type converted n-HgCdTe into p-type. The activation energy of the process was determined to be 0.99eV regardless to the gas species used for the type conversion process. However, the absorption edge moved toward short-wave direction for hydrogen-plasma-treated sample. The absorption edge shift was observed even after the annealing process, which means the passivation and junction formation are separate phenomena.

In this study, the effects of hydrazine treatment on the surface of HgCdTe were investigated by X-ray photoelectron spectropscopy (XPS) and metal–insulator–semiconductor (MIS) capacitance–voltage (C–V) analyses. By the XPS analysis, it was found that the Te4+ oxide peak at 576.2 eV disappeared clearly from the surface of HgCdTe after hydrazine treatment. The hydrazine-treated sample showed a near-flatband condition, small hysteresis, and a high-frequency characteristic in C–V measurements. The photodiodes fabricated on hydrazine-treated HgCdTe showed dynamic resistance-area product values at zero bias (R 0 A) of ∼2.54 Ω cm2 for a junction area of 30×30 µm2, which are about ten times larger than those on Br-treated HgCdTe.

We first report the feasibility of using large-grain polycrystalline silicon films as a sensing material for infrared bolometers. To increase the average grain size of polysilicon films, we used seed selection through ion channeling, which resulted in a large grain size of 1670 Å. The temperature coefficient of resistance (TCR) at 20°C and the grain boundary defect density of the film were as high as -2.46%/K for a resistivity of 30 Ω cm and about 1.752×1012/cm2, respectively. From the measurement of noise characteristics of the film, the value of k, 1/ f noise parameter, was calculated to be 1.35×10-9. As a result, the estimated detectivity was found to approach 5.6×108 cm Hz1/2/W.

(Ba0.5Sr0.5)TiO3 thin films were deposited on Pt/TiO2/SiO2/Si substrates with various TiO2 adhesion layer thicknesses. The crystallinity of Pt thin films with (111) direction and the electrical properties of BST thin films strongly depend on the TiO2 adhesion layer thickness. TiO2 adhesion layers between the Pt and SiO2 layers with thicknesses smaller than 5 nm show good adhesion properties and a low leakage current density of BST thin films deposited on the Pt/TiO2/SiO2/Si substrate, which is lower than 8.8×10-8 A/cm2 at an applied voltage of 1 V. The optimal thickness of the TiO2 adhesion layer in the Pt/TiO2/SiO2/Si structure is very important to obtain good electrical properties of BST thin films as well as good adhesion properties.

A new readout circuit involving two-step current-mode background suppression is studied for two-dimensional long wavelength infrared (2D LWIR) focal plane arrays. The simple pixel circuit has a very small skimming error of less than 0.3%, low noise characteristics for an adequate calibration range, and a long integration time of 2 ms.

A readout circuit involving a time-based pixel-level ADC is studied for two-dimensional long wavelength infrared focal plane arrays (2-D LWIR FPAs). The integration time of each pixel can be optimised individually and automatically. Using a time-based pixel-level ADC with two-step background suppression, the signal-to-noise ratio and dynamic range can be improved to 88.8 and 95.1 dB, respectively.

A new CMOS readout circuit that controls the non-uniformity of microbolometer arrays as a function of operating temperature change is described. This circuit provides a nonlinear bias current for operating temperature using a MOS transistor that is operated in the subthreshold region. This approach allows microbolometer arrays to operate without temperature stabilisation up to an operating temperature change of approximately 40K.

Structural and electrical characteristics of Pb(Zr, Ti)O3 (PZT) ferroelectric thin films deposited on various Ir-based electrodes (Ir, IrO2, and Pt/IrO2) using electron cyclotron resonance plasma enhanced chemical vapor deposition were investigated. On the Ir electrode, stoichiometric PZT films with pure perovskite phase could be obtained over a very wide range of processing conditions. However, PZT films prepared on the IrO2 electrode contain a large amount of PbOx phases and exhibited high Pb-excess composition. The deposition characteristics were dependent on the behavior of PbO molecules on the electrode surface. The PZT thin film capacitors prepared on the Ir bottom electrode showed different electrical properties depending on top electrode materials. The PZT capacitors with Ir, IrO2, and Pt top electrodes showed good leakage current characteristics, whereas those with the Ru top electrode showed a very high leakage current density. The PZT capacitor exhibited the best fatigue endurance with an IrO2 ...

A smart time delay and integration (TDI) readout circuit is suggested which performs background suppression, cell-to-cell non-uniformity compensation, and dead pixel correction. Using the smart TDI readout circuit, the integration capacitor area occupying almost the whole area of a unit-cell can be reduced to one-fifth and transimpedance gain can increase by five times. From measurement results, it is found that the skimming current error for a few hundred nA background current is

A new noise reduction circuit that suppresses noise bandwidth of the output stage is proposed for the readout circuit of an infrared detector operating at a high pixel rate. Using this circuit, it is found that the rms noise voltage of the output stage is effectively reduced from 87 to 52 /spl mu/V at a pixel rate of 10 pixel//spl mu/s.

Polycrystalline Pb(Zr,Ti)O3 (PZT) films were fabricated at a low temperature of 450°C by the electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR PECVD) method. Stoichiometric PZT films with the pure perovskite phase could be obtained over a wider range of deposition conditions on Pt/RuO2 hybrid electrodes than on RuO2 electrodes. PZT capacitors fabricated on Pt/RuO2 hybrid electrodes showed low leakage current and superior polarization characteristics compared with those on RuO2 electrodes. PZT capacitors fabricated on Pt/RuO2 were not as fatigue-free as those on RuO2 but had higher resistance to fatigue than those on Pt. The introduction of a PbTiO3 buffer layer prior to PZT film deposition on Pt/RuO2 improved the fatigue characteristics by suppressing the formation of nonstoichiometric interfacial layers. Good leakage current property (J: 5.8 ×10-7 A/cm2 at 200 kV/cm) and fatigue characteristic (P * - P ∧: 9% drop after 4 ×109 fatigue cycles) could be obtained for the 110-nm-thick PZT film using Pt/RuO2 hybrid top and bottom electrodes. This electrode structure is thought to be promising for use as a capacitor of high-density ferroelectric random access memory (FRAM) devices. The fatigue model that can explain the fatigue characteristics of PECVD-PZT capacitors with various hybrid electrode configurations is also suggested.

A precise condition on the spatial resolution of the IR collimator for testing thermal imaging systems is presented. The condition can be used even if only the spatial resolution of the IR collimator and that of the system under test, measured using popular definitions, are known. It is shown that when the condition is fulfilled, the thermal image degradation caused by the IR collimator is negligible.

A four-terminal gate-controlled diode structure has been used to characterize the surface recombination velocity of HgCdTe. The electrical performance of the gate-controlled diode fabricated using x=0.3 HgCdTe was characterized by capacitance-gate voltage and current-gate voltage measurements. A theoretical model was developed for the total dark current in the gate-controlled diode structure and used to fit the experimental data. Data fitting when the experimental device was operated in depletion mode allowed the simultaneous extraction of the surface recombination velocity, 170 cm/s, the generation lifetime in the n-p junction depletion region, 12 ns, and the generation lifetime in the gate induced junction depletion region, 500 ns.

The etching and ferroelectric properties of SrBi2Ta2O9 (SBT) thin films prepared by metal organic decomposition (MOD) were investigated. It was observed that the etching rates of SBT thin films varied with the etch parameters. The etching rate of SBT in gases with Ar added is higher, which indicates that the physical bombardment could be more efficient in SBT etching. We also investigated the influence of etching damage in SBT films during the reactive ion etching (RIE) process on the electrical properties of ferroelectric materials.

Deoxidization phenomenon of iridium oxide (IrO2) film, which has been used as a diffusion barrier for ferroelectric capacitors, is investigated changing the temperature and oxygen pressure during the post process. The deoxidization is well understood by explaining the relationship between the temperature and dissociation pressure according to the thermodynamics. A simple thermodynamic calculation for the deoxidization of IrO2 gives a guideline for successive process condition at which the stability of IrO2 films can be maintained.

The effects of an iridium (Ir) electrode on the properties of Ba0.5Sr0.5TiO3 (BST) films were studied, in comparison with a conventional platinum (Pt) electrode. It was found that the dielectric constant of BST films is strongly dependent on the electrode material. The BST films deposited on an Ir bottom electrode were preferentially oriented and showed higher dielectric constants than those on Pt. Higher dielectric constants of the BST films could also be obtained by using Ir instead of Pt as a top electrode material, which was explained as being due to the compressive stress in the BST film induced by the Ir top electrode.

A new input circuit, called the current mirroring direct injection (CMDI) circuit, is proposed for infra-red detector readouts. This new input circuit leads to almost 100% injection efficiency even in the case of low diode dynamic resistance. In addition, it can provide a stable detector bias and can be implemented with a small unit cell area and low power consumption.

In this study, the rapid thermal diffusion (RTD) of indium and its activation as a donor in p-Hg0.70Cd0.30Te/CdTe were investigated using atomic indium and electron concentration profiles obtained by secondary ion mass spectroscopy (SIMS) and differential Hall measurements, respectively. Photodiodes with a junction formed by the RTD of indium were also demonstrated. There are two diffusion components, a complementary error function fitted atomic diffusion component and an exponentially fitted fast diffusion component. The diffusion coefficients of atomic indium into p-Hg0.70Cd0.30Te by RTD can be fitted as D(T)( cm2/s)=1.45×10-2exp (-0.772(eV)/kT) in the temperature range of 100–200°C. It is observed that diffused indium atoms are partially activated as donors and that the ratio of electron to diffused indium concentration is increased with increased diffusion depth from the surface. For photodiodes with an indium RTD junction, trap-assisted tunneling current is markedly suppressed. The origin of suppression of trap-assisted tunneling current can be explained by suppression of defect generation in the depletion region during junction formation by the RTD process.

A new method is reported for estimating the steady-state effective minority carrier diffusion length. The diffusion length is determined by measuring photocurrents which decrease exponentially with the distance between the junction edge and the region into which environmental infrared light penetrates. The region exposed to infrared radiation can be defined using an optical shadow mask. Using this method, the steady-state effective minority carrier diffusion length of photodiodes fabricated on p-type bulk Hg0.7Cd0.3Te was determined to be 19 µ m at all points on the wafer.

Platinum (Pt) bottom electrodes have been prepared on SiO2/Si substrates at various deposition temperatures by electron-beam evaporation. Subsequently, (Ba0.5Sr0.5)TiO3 (BST) films were grown under identical conditions by rf magnetron sputtering. It was found that the crystallinity of BST thin films on the Pt bottom layers was strongly dependent on that of Pt films. The surface morphology of BST films appeared to be closely related to the change in the stress of Pt films during BST deposition. In addition, the stress of Pt film has been proven to affect the electrical properties such as current-voltage characteristic and capacitance-voltage characteristic.