Plasma surface reactions important in the processes of semiconductor fabrication are reviewed. Plasma etching mechanisms are discussed from the relationship between the etching characteristics and the plasma diagnostics results. Oxide etching using a novel chemistry is also presented, which indicates the importance of the electron collision cross section measurement for various feedstock gases employed in plasma processing.

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In this study, Ar gas-puff z-pinch plasma is produced by an inductive pulsed power system. Gap length dependency of the z-pinch plasma characteristics such as a pinching plasma behavior, soft x-ray emissions, spatial distribution of hot spots is investigated. The soft x-ray output is increased with the gap length and hot spots generated by the sausage instability is distributed along the z-axis in case of shorter delay time of the discharge onset. However, hot spots are distributed in the center of the gap space with the increase of the delay time in any gap length and the number of hot spots is decreased.

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Time-of-flight (TOF) transient currents affected by circuit time constants of RC at the measurements are calculated. The one-dimensional carrier distributions by diffusion and drift transport are used, and the strong drift and the weak drift transport induce the typical TOF currents, the non-dispersive and the dispersive types, respectively. For these waveforms, it is examined whether we should choose the current or the voltage measurements, from the RC and the observation time scale. The simulation results here pointed out that in the case of either TOF type, the TOF current method required the set up of RC value less than 1/100 of the transit time Tr, and that the voltage method required the RC more than 100 times of Tr and additionally at the voltage measurements the circuit time constants has no influence upon the TOF waveforms in the initial time.

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The purpose of this study is to control the input impedance of the composite electromagnetic wave absorbers without changing their composition using ITO thin film as resistive thin film, which coats electromagnetic wave absorbers made of Ni-Zn ferrite and ferrite composites (spinel-type Ni-Zn ferrite, SiO₂). The electromagnetic characteristics and absorption characteristics of these wave absorbers were evaluated. Compared with ferrite composites without ITO thin film, absorbing center frequency with the band width of the absorption above 90% of ferrite composites with ITO thin film was shifted to the lower frequency region. The range of the thickness for which electromagnetic wave is absorbed above 90% became broad using ITO thin film. These results shows that electromagnetic wave absorbers coated with ITO thin film with the requested center absorbing frequency can be made by choosing the suitable thicknesses of both the film and the ferrite composite without changing the composition of the absorber.

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High concentration ozone formation due to the micro gap silent discharge by using cylinder ozone generator which has a glass lining ground electrode and direct cooling type high voltage electrode is discussed. The cooling efficiency of the electrode is high and effective to prevent heat decomposition of ozone. Micro gap ozone generating tube of an discharge gap length of 0.15mm was produced by improvement of the manufacture technology. We confirmed that the discharge gap length is maintained 0.15 mm by measuring a size of electrodes and discharge power versus peak voltage. Discharge maintain voltage is proportional to gas pressure product discharge gap length. Ozone concentration obtained using the micro gap electrode is about 300g/Nm³ at the power density W/S (discharge power/discharge area) of 0.3 watt/cm². This is the same level as the characteristic of the parallel plane electrode with ceramic.

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We propose a novel method for producing a high repetitive frequency short pulse to use a halved confocal of an unstable concave and convex resonator on very high frequency (VHF) discharge excitation slab type carbon dioxide laser. This method utilizes a full reflection concave mirror with a function of variable curvature, which can be controlled using a piezo electric device. Generally, slab type lasers are modulated directly by varying pulse voltage. However, there is a fluctuation of plasma at the transition of the pulsation. Consequently, the repetitive frequency is less than 10 kHz, the minimum pulse width is 1μs. On the other hand, there is no disturbance of the plasma, because the power source is not modulated in our method. And the mechanical constraint is also little, because it are used a piezo electric device. So, pulse shortening of the high repetition is possible. The pulse shape was nicely reproduced when we calculate to use the three-level rate-equation. The mechanism of the method is interpreted to attribute the changed the ejection efficiency to the vibrated along the radius of curvature of the mirror. Good agreements between the observation and the calculation are also obtained in the peak power and the pulse width. In this paper, we compared the measurement with the calculation. Then, the possibility of high repetition oscillation and pulse shortening was examined by this method. From the results, the repetitive frequency confirmed between 1.4 kHz and 170 kHz. The pulse width can be realized to shortest 160 ns.

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To investigate the effect of compound of high melting point materials into Cu on current chopping characteristics, the arc instability starting current and chopping current were evaluated for various Cu-base materials. As a result, both the arc instability starting current and chopping current of Cu base alloys were reduced by the addition of the refractory materials. In case of compounding high melting point metals, it was presumed that the reduction rate of chopping current was mainly related to the vapor generation ability of high melting point metals which were superheated by the energy of arc discharge. In case of compounding carbides or carbon, the reduction rate was affected by the chemical state of carbon in the material as well as the content of carbon.

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Amorphous carbon nitride (CNx) thin films are recognized to have potential for applications like hard coating and electron field emission device. In this paper we have optically studied the dynamics of the plasma plume during preparation of CNx thin films by KrF excimer laser (λ=248 nm) ablation of pure graphite target in a pure NH₃ gas. It was found that carbon atoms emitted from the target react with ambient gas. CN and N₂ molecules are formed in the gas phase. We have prepared the CNx thin films at various NH₃ gas pressure and laser fluence on Si (100) and quartz substrates. The N/C ratios of the CNx films depended on the ambient NH₃ gas pressure and laser fluence. We obtained the maximum N/C ratio of 0.62 at NH₃ pressure of 100 mTorr. The typical absorption of CN bonds such as sp² C-N, sp³ C-N, G band and D band were detected from the infrared absorption measurement by FTIR for the deposited CNx thin films.

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The behavior of solution droplets placed on the surface of the polycarbonate plate under dc field was investigated experimentally. In order to investigate the effects of the content of flame retardant on the energy of discharges occurring between the two electrodes, the content of the flame retardant of polycarbonate plate varied at 15%, 10%, 5% and 0%. The solution droplet was placed on the polycarbonate plate in contact with the needle (copper wire) electrode. It was proven that the contact angle between the sample surface and solution droplet decreased with increasing the content of flame retardant. On the sample surface, the droplet is easier to be extended to the opposite side electrode with applied negative bias voltage than with applied positive bias voltage. The extension distance of the droplet change to be short, as the content of flame retardant was increased. The time start to discharge was shorter with applied positive voltage than with applied negative voltage. As the content of flame retardant was increased, the time to discharge was decreased. The discharge energy on the sample surface was increased, with increasing the content of flame retardant.

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Photooxidation effects on the electroluminescent properties in a poly(p-phenylene vinylene) derivative MDOPPV have been studied. The polymer light-emitting devices (PLEDs) used have a semitransparent Al cathode to make the photodegradation rate of the polymer film in the device comparable to that of a naked polymer film. Upon photoirradiation in air, the external quantum efficiency of the device remained constant, while the emission intensity at a constant voltage rapidly decreased. On the other hand, under similar photoirradiation condition, an MDOPPV film, whose thickness in the same as the polymer film in PLED, showed rapid bleaching of the optical absorption corresponding to π-π^* transition as well as rapid decrease of the photoluminescence quantum efficiency. These results suggest that the photodamaging of carrier transport/injection properties of the polymer plays a key role in the photodegradation of PLED based on MDOPPV, rather than the photocreation of defects acting as exciton quenchers.

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Recently, organic materials have been widely used as insulators for electrical elements in various environmental conditions. The importance of this information for preventing fires in electric appliances and devices has been established, and the tracking and ignition of organic insulating materials has been investigated as the origin of fires. This paper describes the effects of temperature and flame-retardant on the discharge characteristics. The experiment was carried out by dc impulse voltage. The test samples of epoxy resin laminate with and without flame-retardant have been employed to investigate the effects of temperature on discharge energy in the range from 20 to 150°C. The changes of contact angle and discharge quantity are discussed with increasing temperature and adding flame-retardant. The solution droplet and placed on the plate of epoxy resin laminate in contact with the needle electrode. The author found that the contact angle decreased with increasing sample temperature, and decreased with adding the flame-retardant. As the test results, the droplet is easier to be extended to the opposite side electrode with applied positive bias voltage (as the voltage applied at plate electrode side) than with applied negative bias voltage (as the voltage applied at needle electrode side). The speed of extending length of droplet is faster with the sample of added flame-retardant than the sample of without flame-retardant. The discharge energy of every samples with added flame-retardant was larger than the samples of without flame-retardant. The author also found that with increasing temperature the discharge energy was increased.

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This paper deals with the statistical estimation of the maintenance cost reduction when insulation diagnosis for power apparatus is performed. A failure loss is expected if a proper alert has not been made because of “too loose diagnosis”. On the other hand, prematurity loss is expected if the apparatus has been replaced because of too early alert made by “too severe diagnosis”. The expected total loss is estimated as a function of risk ratio of the diagnosis. The loss depends on the precision of diagnosis and age of the apparatus as well. The minimum cost condition is realized by selecting a proper risk ratio. The cost reduction effect by diagnosis is also estimated by comparing with the maintenance costs without diagnosis. If the loss is lower than both “expected prematurity loss with immediate replace” and “expected failure loss with continuous operation”, the cost benefit is brought by the diagnosis. The better diagnosing precision brings the lower loss. A case study was performed assuming some realistic parameters.

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A recent research which connects the informations from spin-current with the spin of electron is introduced. Those informations are not obtained from the probabilistic interpretation by Born. Several important facts concerned with spin-current are pointed out. The relation to Zitterbewegung of electro n is also shown.

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