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Insulating SiO x film was deposited with newly developed plasma source at low temperature for fabrication of flexible devices on plastic substrate. The plasma was generated with electromagnetic field by two facing electrodes including magnets inside and covered with SiO 2 targets. The higher deposition rate was achieved from 2.0 to 33 nm/min, with the mixture of tetramethylsilane and oxygen as source gases. The insulating properties were obtained as 3 × 10 −8 A/cm 2 at the electric field of 1 MV/cm, and the breakdown voltage of 5 MV/cm at 1 × 10 −6 A/cm 2 for the film deposition rate at 11.6 nm/min. High density plasma enhanced by magnetic field would be the hopeful solution for gate insulator deposited at high deposition rate with low temperature.

The multi-layered structure of thin diamond-like carbon (DLC) films was investigated by X-ray reflectivity (XRR) analysis. Thin DLC films were deposited on Si substrate by RF plasma chemical vapor deposition (CVD) from acetylene source gas with short duration of plasma operation from 0.08 to 4.99 s. It was confirmed from XRR analysis that the thin DLC film on Si substrate had 3 layers consisting of a subsurface layer on the grown surface, a mixing layer at the interface to Si substrate, and a bulk-DLC layer sandwiched between the 2 layers. The 3 layers had been formed in 0.08 s at beginning of deposition with distinctive bulk-DLC layer of 1.7 nm thick already appeared due to extremely higher deposition rate only at the initial stage of CVD. The thickness of bulk-DLC layer increased with increasing CVD duration while both the mixing layer of higher density and the sub-surface layer of extremely low density continuously existed. By oxygen plasma etching, it was confirmed by XRR analysis that the sub-surface layer was clearly removed and another layer of lower density than the bulk DLC appeared.

The trap densities (D t) in ZnO thin-film transistors (TFTs) with SiNx / SiOx stacked gate insulators fabricated using several N2O flow rate during SiOx deposition (R N2O) are extracted. It is found that the trap states consist of deep flat states and shallow tail states. The deep states are similar, whereas the tail states vary as R N2O varies. It is also found that the degree of the characteristic stability corresponds to D t of the tail states.

Density of 3 × 1011/cm2 and diameter of CNTs of 9–12 nm were successfully controlled by using the multi-layered catalyst film consisting of an additional Ni layer on Fe/Al catalyst film. EDS analysis for the annealed catalyst films revealed that the increase of the density of Fe catalyst particles corresponded with the decrease of Ni in the films, which strongly suggested that the additional thin Ni layer on the Fe/Al multi-layered catalyst films prevented the fine Fe catalyst particles from agglomeration, resulting in the growth of high-density, and uniform diameter of CNTs.

A long time operation of field electron emission over 45,000 h was achieved using the screen printing carbon nanotube (CNT) emitter fabricated on an ITO coated glass substrate. The measurement was carried out in an ultra-high vacuum chamber at around 3 × 10 − 7 Pa in pressure with continuously applying voltage of rectangular pulses at 743 V or 730 V peak, 60 Hz frequency and 10% duty ratio. The emission current corresponding to the voltage pulse at 1.27 mA/cm 2 density was repeatedly and reproducibly observed for more than 5 years. Because the operated condition was 10 times higher at the current density than that of the conventionally developed field emission lamps (FELs), the expected lifetime of the presented emitter will be 450,000 h though the vacuum level of the measurement was extremely higher than that of the actual operation of FELs. By investigating the morphology of the emitter after terminating the operation, it was found that sparse bundles of agglomerated CNTs were standing in the long lifetime CNT emitter.

The effect of oxidation, oxygenation, and de-oxygenation arising from He gas jet and He plasma jet treatments on the viability of skin cells cultured in vitro has been investigated. He gas jet treatment de-oxygenated cell culture medium in a process referred to as "sparging." He plasma jet treatments oxidized, as well as oxygenated or de-oxygenated cell culture medium depending on the dissolved oxygen concentration at the time of treatment. He gas and plasma jets were shown to have beneficial or deleterious effects on skin cells depending on the concentration of dissolved oxygen and other oxidative molecules at the time of treatment. Different combinations of treatments with He gas and plasma jets can be used to modulate the concentrations of dissolved oxygen and other oxidative molecules to influence cell viability. This study highlights the importance of a priori knowledge of the concentration of dissolved oxygen at the time of plasma jet treatment, given the potential for significant impact on the biological or medical outcome. Monitoring and controlling the dynamic changes in dissolved oxygen is essential in order to develop effective strategies for the use of cold atmospheric plasma jets in biology and medicine. Refereed/Peer-reviewed

The relationship between the physical structure of carbon nanotube (CNT) honeycomb structures and their total, diffuse, and specular reflectance is investigated for the first time. It is found that CNT honeycomb structures with average cell areas of smaller than 30 μm2 show a higher total reflectance. Particularly, a thinner, highly packed CNT (buckypaper) film, along with a larger wall height and higher ratio of wall height to cell area, markedly increase the total reflectance for cell areas smaller than 30 μm2, which means that a higher total area of buckypapers in CNT walls and bottom areas increases the total reflectance, including the diffuse reflectance. It is also found that the total reflection of non-absorbed light in CNT honeycomb structures consists primarily of diffuse reflectance.

The exceptional properties of carbon nanotube metamaterial — a synergy between CNT forest and electromagnetic circuits, is highly expected. In this work, infrared optical properties of patterned CNT forest for metamaterial will be presented. The bulk properties of patterned self-standing homogenous CNT forest in the infrared region were investigated. The influence of CNT metamaterial patterns on the IR absorbance was studied.

The plasma jet generation of reactive oxygen and nitrogen species (RONS) in solution is important in biology, medicine, and disinfection. Studies using a wide variety of plasma jet devices have been carried out for this purpose, making it difficult to compare the performance between devices. In this study, we compared the efficiency of RONS generation in deionized (DI) water between 3.7-mm- and 800-µm-sized helium (He) plasma jets (hereafter mm-jet and µm-jet, respectively) at different treatment distances and times. The efficiency of RONS generation was determined by considering the total amount of RONS generated in DI water with respect to the input energy and gas consumption. We found that the mm-jet generated 20% more RONS in the DI water than the µm-jet at the optimized distance. However, when the input power and He gas consumption were taken into account, we discovered that the µm-jet was 5 times more efficient in generating RONS in the DI water. Under the parameters investigated in this study, the concentration of RONS continued to increase as a function of treatment time (up to 30 min). However treatment distance had a marked effect on the efficiency of RONS generation: treatment distances of 25 and 30 mm were optimal for the mm-jet and µm-jet, respectively. Our method of comparing the efficiency of RONS generation in solution between plasma jets could be used as a reference protocol for the development of efficient plasma jet sources for use in medicine, biology, and agriculture.

The efficacy of helium (He) and argon (Ar) plasma jets are being investigated for different healthcare applications including wound and cancer therapy, sterilisation and surface disinfections. Current research points to a potential link between the generation of reactive oxygen and nitrogen species (RONS) and outcomes in a range of biological and medical applications. As new data accrue, further strengthening this link, it becomes important to understand the controlled delivery of RONS into solutions, tissue fluids and tissues. This paper investigates the use of He and Ar plasma jets to deliver three RONS (hydrogen peroxide—H2O2, nitrite—$\text{NO}_{2}^{-}$ and nitrate—$\text{NO}_{3}^{-}$ ) and molecular oxygen (O2) directly into deionised (DI) water, or indirectly into DI water through an agarose target. The DI water is used in place of tissue fluid and the agarose target serves as a surrogate of tissue. Direct plasma jet treatments deliver more RONS and O2 than the through-agarose treatments for equivalent treatments times. The former only deliver RONS whilst the plasma jets are ignited; the latter continues to deliver RONS into the DI water long after the plasmas are extinguished. The He plasma jet is more effective at delivering H2O2 and $\text{NO}_{2}^{-}$ directly into DI water, but the Ar plasma jet is more effective at nitrating the DI water in both direct and through-agarose treatments. DI water directly treated with the plasma jets is deoxygenated, with the He plasma jet purging more O2 than the Ar plasma jet. This effect is known as 'sparging'. In contrast, for through-agarose treatments both jets oxygenated the DI water. These results indicate that in the context of direct and indirect plasma jet treatments of real tissue fluids and tissue, the choice of process gas (He or Ar) could have a profound effect on the concentrations of RONS and O2. Irrespective of operating gas, sparging of tissue fluid (in an open wound) for long prolonged periods during direct plasma jet treatment, could have implications for healthy tissue function; whilst through-tissue plasma jet treatment may provide a method to reperfuse oxygen-starved tissue. The assays described in this paper can be readily adopted (by others) and may support the future development of plasma sources to deliver specific (metered) doses of RONS.

We have proposed a multi-scale Monte Carlo simulation method of neutron induced soft errors by linking a particle transport code PHITS and a 3-D TCAD simulator HyENEXSS. An interface tool between PHITS and HyENEXSS is developed to generate the mesh structure optimized for an event where multiple secondary ions extending to arbitrary directions are generated simultaneously by neutron incidence on device. Using the interface tool, we have made it possible to perform the Monte Carlo calculation of soft error rates (SERs) based on event-by-event device simulation. The PHITS-HyENEXSS code system has been successfully applied to SER analyses for 65 nm, 45 nm, and 32 nm technology MOSFETs.

Lean body mass decreases after a major operation such as open-heart surgery, which leads to postoperative complications, as a drastic loss of muscle mass is related to infections and longer hospital stays. The purpose of this study was to examine changes in lean body mass and muscle mass including body composition the perioperative phase until discharge in patients undergoing open-heart surgery. Body fluids, fat and lean body mass in 17 patients were determined before and 1 week after surgery, and at discharge using bioelectrical impedance analysis. In addition, the levels of hemoglobin, albumin, and C-reactive protein in blood were measured. Cardiac rehabilitation consisted of early mobilization and aerobic bicycle exercise was subsequently performed after confirmation of independent walking for 200 meters. Early mobilization after surgery was assisted by physical therapists experienced in cases of cardiovascular surgery. Early mobilization required no more than 3 delayed days and no major complications until discharge in any of the patients. Weight and body mass index were significantly lower at discharge than before and 1 week after surgery, while lean body mass, muscle mass, total body water, intracellular fluid, body protein, and body cell mass values were significantly lower at discharge than before surgery. The changes in body composition seen after cardiac surgery until discharge indicated continuous catabolic reactions in our patients and some cytokines have been suggested to influence this phenomenon. After receiving open-heart surgery, it is important for patients to receive nutritional therapy and begin resistance exercise as soon as possible. Aerobic exercise should produce muscle protein synthesis and increase muscle mass under adequate nutritional support including specific amino acid supplements. Our findings indicate that muscle mass and nutritional status should be monitored after discharge and followed consistently in patients after open-heart surgery.

Trap densities in the channel layers Dt of ZnO thin-film transistors have been extracted. First, the low-frequency (low-f) capacitance-voltage C-V characteristics are measured using the customized measurement system. Next, the surface potential is calculated from the low-f C-V characteristic, and the surface potential gradient is calculated by applying Gauss's law. Finally, the spatial profile of the electric potential is calculated by applying Poisson equation and carrier density equations, and Dt is extracted. It is found that, generally, the deep states are flatly distributed in the energy gap apart from the conduction band, and the shallow states seem to be the tail states. Moreover, the dependence on the oxygen partial pressure during the sputtering of ZnO films [p(O2)] has been analyzed. It is found that for p(O2) = 0.50 ~ 0.75 Pa, Dt changes little, whereas for p(O2) = 0.17 ~ 0.33 Pa, Dt increases. It is clarified that the abnormal shapes of the current-voltage and low-f C-V characteristics originate from the increase of Dt.

Micro-arc discharge plasma was generated in highly conductive seawater at high pressures up to 19 MPa. Using a microscaled rod-to-rod electrode system, a micro-arc discharge was ignited reproducibly using voltages below 850 V. Even at high pressure, the current and voltage characteristics showed the same scheme of micro-arc discharges as those at atmospheric pressure. The energy consumption for the preheating phase, in which bubbles were generated by joule heating and micro-arc discharges were consequently ignited in the bubbles, gradually increased from 5 to 36 mJ with an increase in pressure from 0.1 to 19 MPa. The micro-arc discharge plasma at high pressure exhibited high-luminance photo-emissions with distinctive spectra consisting of an intense flat continuum band and extremely broadened peaks.Micro-arc discharge plasma was generated in highly conductive seawater at high pressures up to 19 MPa. Using a microscaled rod-to-rod electrode system, a micro-arc discharge was ignited reproducibly using voltages below 850 V. Even at high pressure, the current and voltage characteristics showed the same scheme of micro-arc discharges as those at atmospheric pressure. The energy consumption for the preheating phase, in which bubbles were generated by joule heating and micro-arc discharges were consequently ignited in the bubbles, gradually increased from 5 to 36 mJ with an increase in pressure from 0.1 to 19 MPa. The micro-arc discharge plasma at high pressure exhibited high-luminance photo-emissions with distinctive spectra consisting of an intense flat continuum band and extremely broadened peaks.

Thermal stability of sputter deposited ZnO thin films was evaluated by thermal desorption spectroscopy (TDS). Desorption of Zn was mainly observed from the films deposited at low O 2 /Ar gas ratio and low RF power. In contrast, O 2 desorption was mainly observed from the films deposited at high O 2 /Ar gas ratio and high RF power. The amount of desorbed O 2 from the film increased with increasing the O 2 /Ar gas flow ratio and the RF power. Furthermore, the desorption temperature of O 2 increased with increasing the RF power during the deposition. Thermal stability of the ZnO films was controlled not only by the O 2 /Ar gas flow ratio, but also applied RF power to the target.

The field emissions of the in-plane-type triode carbon nanotube emitters for the field emission backlight lamps were investigated in simulation by the finite element method in order to indicate ideal high efficient field emission fluorescent lamps (FELs). The anode current are commonly controlled by the gate bias voltages for the FEL triode emitters. The simulation of the in-plane-type triode emitter indicated that the ON/OFF ratio of the anode current density for the gate bias voltage of 0 V/−100 V was increased by decreasing the cathode to gate spacing, by decreasing the cathode and gate electrode width, and by using the lower ratio of the cathode to the gate electrode width.

The activation behavior of boron (B) implanted poly-Si films on glass substrates has been investigated. The effect of B dose and annealing temperature on crystal defects and electrical properties of the films were evaluated by Raman spectroscopy and Hall measurement. It was found that the maximum activation ratio of the film with B dose of 1 × 10 15 cm − 2 was obtained when Raman peak associated with disordered amorphous silicon disappeared. However, reverse anneal was observed in the film when the annealing temperature further increased. The results from secondary ion mass spectrometry and Hall measurement revealed that B segregation at the top and bottom interface and deactivation of B substitutional occurred simultaneously in the high-dose specimens when the annealing temperature increased from 600 to 750 °C.

The circuit design, assembly, and operating tests of a high-frequency and high-voltage (HV) pulsed dc generator (PDG) for capacitively coupled plasma (CCP) discharge inside a vacuum chamber are reported. For capacitive loads, it is challenging to obtain sharp rectangular pulses with fast rising and falling edges, requiring intense current for quick charging and discharging. The requirement of intense current generally limits the pulse operation frequency. In this study, we present a new type of PDG consisting of a pair of half-resonant converters and a constant current-controller circuit connected with HV solid-state power switches that can deliver almost rectangular high voltage pulses with fast rising and falling edges for CCP discharge. A prototype of the PDG is assembled to modulate from a high-voltage direct current (HVdc) input into a pulsed HVdc output, while following an input pulse signal and a set current level. The pulse rise time and fall time are less than 500 ns and 800 ns, respectively, and the minimum pulse width is 1 µs. The maximum voltage for a negative pulse is 1000 V, and the maximum repetition frequency is 500 kHz. During the pulse on time, the plasma discharge current is controlled steadily at the set value. The half-resonant converters in the PDG perform recovery of the remaining energy from the capacitive load at every termination of pulse discharge. The PDG performed with a high energy efficiency of 85% from the HVdc input to the pulsed dc output at a repetition rate of 1 kHz and with stable plasma operation in various discharge conditions. The results suggest that the developed PDG can be considered to be more efficient for plasma processing by CCP.

63kA-50Hz 90% short line fault (L90) is severer than 50kA-60Hz L90 from the points of view of electric endurance and interruption window. Interruption criteria and an optimization method of the chamber design are discussed to improve thermal interruption capability with it. The combination of the SA (Simulated Annealing) and MMFD (Modified Method of Feasible Directions) is applied to the optimization procedure. The optimized chambers with superior electric reliability are designed at 63kA-50Hz to improve gas density at current zero in thermal volume. 63kA-50Hz L90 interruptions are performed with the new chamber. In addition, influence of gas blast angle of nozzle on L90 interruption is clarified.

Ion implantation experiments of indium (In) into sputter-deposited undoped ZnO films were carried out to control the resistivity for n+-ZnO layers of electronic device. Improvement of ZnO crystallinity after the ion implantation was revealed by x-ray diffraction patterns including a shift of lattice parameter, enhancement of peak intensity, and a decrease in full width at half maximum in 2θ. In-implanted ZnO crystallinity was greatly improved compared to results of the Ga and Al-implanted ZnO experiments. The resistivity of 1×1016ions∕cm2 implanted ZnO film was decreased with over 11 orders of magnitude to 5.1×10−2Ωcm with postimplantation annealing at 400°C. The ratio of resistivity between unimplanted ZnO and In-implanted one at 1×1015ions∕cm2 was seven orders of magnitude after annealing at 300°C. The In-implanted ZnO would be suitable for fabricating source and drain regions of ZnO thin film transistors.

Vertically aligned, high-density (4× 109 /cm2) carbon nanotubes (CNTs) with an average short height of 1.5 μm were grown directly on a Cr electrode patterned on a glass substrate at a substrate temperature below 550 °C by water-assisted chemical vapor deposition (CVD). Threshold field of the emission of the patterned grown CNT could be tuned with the pattern shape, and it was 1.8 V/μm at 1 μA/cm2 for the emitter with a hole spacing parameter of S = 20 μm. The stability of field emission of the patterned CNT emitter on glass was confirmed with continuously working more than 24 hours at a pulse current density of 70 μA/cm2 with the duty ratio of 7.5 %. [DOI: 10.1380/ejssnt.2010.336]

Transparent and conductive Al-doped ZnO (AZO) thin films were deposited on substrates including alkali-free glass, quartz glass, Si, and SiO 2 buffer layer on alkali-free glass by using radio frequency magnetron sputtering. The effects of different substrates on the structural, electrical and optical properties of the AZO films were investigated. It was found that the crystal structures were remarkably influenced by the type of the substrates due to their different thermal expansion coefficients, lattice mismatch and flatness. The AZO film (100 nm in thickness) deposited on the quartz glass exhibited the best crystallinity, followed sequentially by those deposited on the Si, the SiO 2 buffer layer, and the alkali-free glass. The film deposited on the quartz glass showed the lowest resistivity of 5.14 × 10 − 4 Ω cm among all the films, a carrier concentration of 1.97 × 10 21 cm − 3 and a Hall mobility of 6.14 cm 2 /v·s. The average transmittance of this film was above 90% in the visible light spectrum range. Investigation into the thickness-dependence of the AZO films revealed that the crystallinity was improved with increasing thickness and decreasing surface roughness, accompanied with a decrease in the film resistivity.

The ZnO films were deposited, respectively, in Ar and Ar/O 2 in order to investigate the effects of positive ions bombardment of argon and oxygen on both the crystallinity and thermal stability of sputtered ZnO films. The TEM and XRD results indicate that crystallite size of the ZnO film increased by the substrate bias as the film deposited in Ar. On the other hand, the preferred orientation of the film was changed from (0 0 2) to (1 0 0) and (1 0 1) by the substrate bias as the film deposited in Ar/O 2 . The thermal stabilities of zinc (Zn) and molecular oxygen (O 2 ) in the ZnO films were investigated by thermal desorption spectrometry. The Zn desorption was drastically suppressed by the P sub when the ZnO film deposited in Ar/O 2 . The substrate bias effectively suppressed the Zn desorption when the film deposited in Ar/O 2 . Grain boundaries play an important role in determining the Zn desorption from the films.

In this paper, high-performance bottom-gate thin-film transistors (TFTs) with transparent zinc oxide (ZnO) channels have been developed. The ZnO film for active channels was deposited by RF magnetron sputtering. The crystallinity of the ZnO film drastically improved when it was deposited on a doublelayer SiOx/SiNx gate insulator. In order to achieve a ZnO TFT back-plane for liquid-crystal display (LCD) with the required pattern accuracy, dry etching of the ZnO film in an Ar and CH4 chemistry has been developed. The etching rate and tapered profile of the ZnO film could be controlled by the Ar content in the etching gases of Ar and CH4. The saturation mobility (musat) of the ZnO TFT strongly depended on a gate voltage. A musat of 5.2 & cm2 .(V .s)-1 at VGS = 40 V and VDS = 10 V, and an on/off-current ratio of 2.7 x 107 were obtained. A drain-current uniformity of plusmn7% was achieved within a radius of 20 mm from the substrate center. A 1.46 -in diagonal LCD with 61 600 pixels has been driven by the ZnO-TFT back-plane. A moving picture image was available on fabricated LCD driven by the ZnO TFTs.

Zinc oxide (ZnO) film was deposited on a glass substrate by rf magnetron sputtering with O2/Ar as working gases. Structural properties of the films were characterized by XRD. Average crystallite size in the films was strongly dependent on both the gas flow ratio of O2/Ar and rf-power at a constant deposition pressure. During the deposition, energetic species in the plasma were in situ monitored using optical emission spectroscopy. An inverse correlation was observed between the average crystallite size and the emission intensity ratio of I O ∗ / I Ar . Bombardment of atomic oxygen to the growing surface played an important role in determining the average crystallite size in the films. The average crystallite size could be controlled by the emission intensity ratio of I O ∗ / I Ar .

Undoped ZnO films were deposited by radio frequency (RF) magnetron sputtering on amorphous buffer layers such as SiO x , SiO x N y , and SiN x prepared by plasma enhanced chemical vapor deposition (PECVD) for dielectric layer in thin film transistor (TFT) application. ZnO was also deposited directly on glass and quartz substrate for comparison. It was found that continuous films were formed in the thickness up to 10 nm on all buffer layers. The crystallinity of ZnO films was improved in the order on quartz>SiO x >SiO x N y >glass>SiN x according to the investigated intensities of (0 0 2) XRD peaks. The crystallite sizes of ZnO were in the order of SiO x ∼glass >SiN x . Stable XRD parameters of ZnO thin films were obtained to the thickness from 40 to 100 nm grown on SiO x insulator for TFT application. Investigation of the ZnO thin films by atomic force microscope (AFM) revealed that grain size and roughness obtained on SiN x were larger than those on SiO x and glass. Hence, both nucleation and crystallinity of sputtered ZnO thin films remarkably depended on amorphous buffer layers.

Zinc oxide (ZnO) films have been deposited on glass substrates by rf magnetron sputtering with Ar/O2 working gases. The crystallite size of the films was characterized by X-ray diffraction (XRD) analysis. At a deposition pressure of 1.0 Pa, the average crystallite size decreased with increasing O2 flow rate. Optical emission spectroscopy (OES) results showed that the average crystallite size can be controlled by the emission intensity ratio of O*/Ar. The XRD results of the ZnO deposited in both Ar/O2 and O2 working gases revealed that the bombardment of the energetic oxygen particles to the growing surface suppresses the surface migration of the sputtered adatoms and that of energetic argon particles enhances the surface migration of the adatoms. The crystallite size and total volume of the crystallite fraction in the film are affected by the flux of both energetic oxygen and argon particles present in the plasma, and are determined by the competition processes of the bombardment of energetic oxygen and argon under a constant deposition pressure.

The effects of postdeposition annealing at up to 350 °C on the crystallinity and thermal stability of sputter-deposited ZnO films have been investigated in terms of the deposition pressure. The average crystallite size and biaxial film stress of an as-deposited ZnO film is strongly related to the deposition pressure. A crystallization process during postdeposition annealing was only observed when the film was deposited under low pressure. Thermal desorption spectrometry (TDS) measurement revealed that Zn desorption from the ZnO film was suppressed with decreasing deposition pressure. Zn desorption from the films was correlated with rf plasma analysis results. It was found that oxygen was desorbed only from the films deposited at low pressure with annealing temperatures above 250 °C. This desorption of oxygen was strongly related to the crystallization process during postdeposition annealing.

SiO2 insulator films were deposited at the substrate temperature of 100 °C by the inductively coupled plasma chemical vapor deposition (ICP-CVD) method using an organic silicon source of tetramethylsilane (4MS) and a N2O precursor. Fourier transform infrared (FT-IR) absorption peaks of O–H stretch, Si–H stretch, and Si–CH3 stretch were not observed in these SiO2 films. The refractive index of SiO2 films at 100 °C was 1.480. These results indicate that typical SiO2 films can be obtained by ICP-CVD using 4MS and N2O by increasing the substrate temperature to 100 °C. Leakage currents of 1.6 nA/cm2 and 1 µA/cm2 at breakdown voltage of 1 and 7 MV/cm, respectively, were achieved.

Polycrystalline zinc oxide (ZnO) films were prepared by radio frequency (RF) magnetron sputtering under different powers. The XRD results showed that ZnO crystallite size along c-axis decreased by 43% with deposition power increased from 60 W to 300 W, increased 36% with annealing temperature rising to400∘C. TDS measurement revealed that the desorption peaks of both atomic Zn (60 W-deposited) and oxygen molecule (180 W and 300 W-deposited) obtained from ZnO films were originated from300∘C. When annealing temperature was higher than300∘C, the sheet resistance dramatically decreased, and compressive stress in the (002) plane changed to tensile stress as well. The comparison measurements of ZnO films crystallinity strongly suggested that both lower deposition power and certain thermal annealing temperature over300∘Cwould contribute to the formation of high quality ZnO films.

We demonstrated the efficacy of using a simple experimental approach, involving UV absorption spectroscopy, to monitor the transport of reactive oxygen and nitrogen species (RONS) through an agarose film (as surrogate for real tissue) into deionized (DI) water. The experiment involved placing a 4 mm thick agarose film over a quartz cuvette filled with DI water. The agarose film was exposed to a non-thermal, He atmospheric-pressure plasma jet (APPJ) and the UV absorption of the DI water was recorded in real-time. Our results indicate an accumulation of RONS within the agarose film during APPJ exposure and a subsequent time-lapsed release of RONS into the DI water. Curve fitting of the UV spectra suggested the APPJ transported and / or generated at least four RONS (NaNO2, HNO3, H2O2 and O2) through the 4 mm thick agarose film. Our approach of analyzing the delivery depth of RONS through synthetic tissue targets might find use in the future development of APPJ medical therapies and for improving our understanding of APPJ interactions with soft tissue. Refereed/Peer-reviewed

The helium (He) atmospheric-pressure plasma jet (APPJ) delivery of reactive oxygen and nitrogen species (RONS) and molecular oxygen (O2) in deionized (DI) water was monitored in real time using in situ UV absorption spectroscopy. The He APPJ was used to treat DI water directly and through an agarose target as a surrogate for tissue (e.g., a skin barrier). For direct treatment, the RONS were generated immediately in the DI water, and the concentration of RONS continued to increase during the He APPJ treatment. But there was only a very minor increase in the total RONS concentration detected after the plasma and gas flow were switched off. The agarose target delayed the generation of RONS into the DI water, but the total RONS concentration continued to increase long after (25 min) the plasma and gas flow were switched off. Direct treatment deoxygenated the DI water, whereas treatment through agarose resulted in oxygenation of the DI water. A dynamic change in the ratio of H2O2, NO2-, NO3-, and O2 was detected in the DI water during He APPJ treatment and 25 min after the He and gas flow were switched off for both direct and through-agarose treatment. These results have implications for the plasma treatment of real tissue where the dynamic changes in the RONS and O2 concentrations within the tissue and tissue fluid could affect cellular and physiological processes. Refereed/Peer-reviewed

An array of very sharp emitter tips, whose top curvatures were less than 10 nm, was fabricated at the surfaces of boron (B)doped high-pressure high-temperature synthetic diamond by reactive ion etching.Electron emission from the emitter arrays was measured using a planar-diode-type I–V measurement system that can also observe a 2D mapping of emission sites by scanning an anode with a 20-mmf pinhole.The shape of each emitter was carefully observed by scanning electron microscopy.It was found that electrons were intensely emitted from the areas where sharp emitters were successfully fabricated.In certain areas, however, electrons were not at all emitted even though very sharp emitters were formed.It was inferred that the emitters were fabricated on growth sectors that had high resistivity. 2003 Elsevier B.V. All rights reserved.

R&D activities on diamond chemical vapor deposition (CVD) and field emission in the Frontier Carbon Technology Project are presented. The topics are (1) morphology control of diamond films grown by a 60-kW, 915-MHz microwave plasma CVD reactor, (2) growth technology of large single crystal diamond with a low density of defects, (3) heteroepitaxial growth technology of diamond films on Pt, (4) fabrication of sharp emitter tips on single crystal diamond, (5) field emission study from diamond particles, and (6) intense field emission from ion implanted homoepitaxial diamond layer. Research results of field emission obtained by Kyoto University and North Carolina State University are also described.

We have investigated the structures of randomly and vertically oriented carbon nanotubes grown by thermal chemical vapour deposition and dual-r.f.-plasma-enhanced chemical vapour deposition, respectively. The randomly oriented carbon nanotubes have a bamboo-like structure, whereas the vertically oriented carbon nanotubes have a multi-shell shape. Both types of nanotubes have a metal nanoparticle at the tip. The field emission property of the randomly oriented nanotube films was better than that of the vertically oriented nanotube films. This result indicates that more emission sites exist at the body than at the tip of the nanotubes. Copyright © 2003 John Wiley & Sons, Ltd.

The diameter control of carbon nanofibers is discussed. Multi-walled carbon nanotubes and carbon nanofibers were formed at 490°C using conventional RF plasma CVD method with an additional RF-substrate power. The diameter of the carbon nanofibers was dependent on substrate temperature, the RF-substrate bias, introducing Ar dilution gas and compositional ratio of NiFe alloy as catalyst for the CVD.

The use of long-term middle ear ventilation tubes (Paparella type II) was retrospectively analyzed in 66 ears with otitis media with effusion, in children treated at Kagawa Medical University Hospital between January 1990 and March 1998. The average intubation period was 23.9 months. The average pure tone air conduction threshold showed a remarkable improvement of between 32.7dBHL and 16.9dBHL. Otorrhea was observed in 25 ears (37.8%), obstruction in 2 ears (3.0%), granulation in 3 ears (4.5%) and permanent ear drum perforation in 11 ears (19.6%). No cholesteatma or adhesion of the ear drum was seen. Recurrence of otitis media with effusion was found in 9 of 45 ears (20.0%). In conclusion, Paparella type II tube can be placed for a long-term period and have a low rate of reccurence, but have a high rate of otorrhea and permanent ear drum perforation.

The electrical properties of thin-film transistors (TFTs) with ZnO channels which were deposited by radio-frequency magnetron sputtering at various oxygen partial pressures [p( O2)] are investigated. A negative shift of the turn-on voltage with a “hump” was observed, and donorlike traps were generated at intermediate energy levels from the conduction band when the ZnO channel was deposited at p(O2) below a critical pressure. Thermal desorption spectroscopy study revealed that the donorlike traps were generated when the ZnO film changed from O- to Zn-rich condition. The Zn-related native defects would be a possible origin of the donorlike traps generated at intermediate energy levels in the ZnO TFTs.