Controllability of pulse-time-modulated reactive plasmas, reactive plasmas, relating to highly precise etching processes with high productivity, reliability and stability for fabrication of ULSI's, is discussed. The method is the most attractive candidate for the next-generation ULSI plasma etching processes with the precise control of reactive species and electron temperature.

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When a reduction of waste and dissolution of iron are carried out by using arc plasma, we need to suppress the arc radiation power, because there are some cases of damaging the furnace wall due to the radiation. In those cases the radiation power from plasma has to be precisely controlled.
However there are few reports on the radiation power from the torch plasma in the past day. So, we tried to measure the radiation power from torch plasma using a power-meter. The radiation power was measured to be about 600 W for an appearance plasma length of 20 mm at 100 A and increases in proportion to the 1.8th power of current.
The radiation efficiency will be 34% in the condition mentioned above in the sphere model. Furthermore, the radiation efficiency for the whole plasma due to wall-stabilized arc model is 27%, and also the radiation efficiency for the torch plasma is 15%.

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A pulsed corona discharge at atmospheric pressure can be used for combustion gas treatment. It is expected to remove NOx and SO2 with low energy consumption. The main process is estimated to be radical reactions such as N and OH with NOx. These radicals are produced by the collisions between fast electrons and major species of combustion gas.
This paper presents a new method for the evaluation of the total amount of N atoms produced by corona discharges. The experiment of N2+NO gas treatment was performed changing the initial NO concentration and keeping the discharge input power constant. Analyzing the data at the high NO concentration region, it was shown that the total amount of N atom production was approximately equal to the reduction quantity of NOx. The energy efficiency of N atom production was estimated to be about 70eV/N-atom and the utilization rate of the effective energy used for N atom production was about 8%.

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Measured breakdown characteristics of capacitively coupled RF discharges are compared with numerical simulations performed under different boundary conditions at the electrode. When a pair of glass-covered aluminum disks are used in the breakdown measurement of N2 and Ar gases at the RF frequency 13.56 MHz, the peculiar bend in the left branch of the minimum of V-shaped breakdown curves is not observed, suggesting the absence of secondary electron emission. For the treated boundary condition of the electron density n, the simulation with its zero gradient gives satisfactory agreement with the experimental V-shaped curves, while the simulation with n=0 is shown to be effective in the region of small electric fields. The development of RF breakdown is explained based on the simulation for spatiotemporal profiles of n.

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Arc-cathode erosion has been studied for tungsten cathode with 2wt% of lanthanum oxide at the current level of 400A in DC. Main results are obtained in case of changing plasma gas from mainly used argon (Ar) to cheaper nitrogen (N2):
(1) Erosion weight increased by 25 to 50 times and the quantity of oxide additives decreased in the tip region. These results suggest that the amount of heat transferred to the cathode increased.
(2) Through 100 hours operation using N2, the electrode eroded with repeating formation and dissipation of a columnar projection at the tip. Even the shape changed in such complicated manner, the erosion weight was almost proportional to the operating time. Referring to the results, we made short electrodes simulating after long operation and estimated the lifetime would be 150 to 300 hours.
(3) Finally, the operation of the plasma torch using N2 was demonstrated in a pilot plant. The erosion weight could be decreased to about 1/3 compared with the results of basic experiments by increasing electrode-cooling capacity.
We conclude that it is possible to choose cheaper N2 instead of more expensive Ar as plasma gas to reduce total operating cost in some application fields such as wide area heating.

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Experimental investigations have been conducted to remove NOx from air streams by a superimposed positive DC/AC corona discharge. The AC peaks voltage and the frequency are 10kV and 10kHz, respectively. The DC bias voltage is from 0 to 30kV. During each cycle of AC applied voltage, several streamers can be produced with inter-streamer time of 200-500ns. NO remove rate is approximately proportional to the square root of the specific energy density. NH3 injection rate significantly reduces NO2 formation per NO removal due to reduction reactions with NH and NH2 and NH3 related heterogeneous processes.

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A new type of a pulsed metallic ion source is proposed. A thin wire is placed in a lowpressure gas and is heated by capacitor energy. Before exploding the wire during maintaining a solid phase, an electrical discharge called shunting arc in the surrounding medium of the wire occurs for the appropriate heating conditions. The deposited wire material and emitted electrons cause the arc when the applied voltage across the wire satisfies the breakdown voltage of the surrounding medium. The wire under its melting point and is used repeatedly for the generation of the discharge. A tungsten wire of 0.1 to 0.4mm in diameter and about 30mm in length in around 1.3kPa gas of air and argon is employed for the arc generation. The arc phenomena are photographed by an image converter camera and the expansion speed of the arc edge reaches at about 1000m/s. From the arc spectra, the metallic fraction in the plasma isconfirmed. The possibility of the usage of a shunting arc discharge as a pulsed ion beam is discussed.

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The electron temperature, the electron density, the electron energy distribution function (EEDF), the optical emission and the metastable density in capacitively coupled helium RF discharges have been measured as a function of applied RF voltage during the transition from an α to γ mode discharge with varying the gas pressure and frequency. As a result, the transition voltage of the discharge mode decreases with decreasing the sheath width or increasing the plasma density depending on the gas pressure and frequency. When the transition occurs, the low energy region of the measured EEDF rose sharply. In the γ mode, the transition of singlet metastable atoms, He(21S), to triplet metastable atoms, He(23S), by the super elastic collision of the low energy electrons play an important role in the glow region. The transition of an α to γ mode is primarily dependent on the ion plasma frequency.

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Heavy erosion of the electrode is one of serious problems in using AC plasma torches. In a series of our studies, a good correlation was obtained between the calculated temperature of electrode tip and the measured electrode erosion. In this paper, the experimental investigation on the electrode sheath drop voltage, one of the most influential factor on the electrode erosion, was carried out and on the basis of the result the investigation on a method of designing electrode size was carried out. The electrode used was of solid type and the material was tungsten containing 2wt% of lanthanum oxide. The plasma gas was argon. Main results are as follows:
(1) The electrode sheath drop voltage Vdrop was calculated on the basis of heat balance in the electrode. As the current increased, the calculated temperature of the electrode tip Tt increased and Vdrop decreased to 2-3V gradually. These results suggested that the higher temperature of the electrode caused the electron to be apt to be emitted from the electrode, and the necessary power for the electron emission and Vdrop dec reased.
(2) The investigation on a method of designing the optimum electrode size was carried out for the desired electrode erosion Ew and arc current, making use of the relation Ew-Tt, the relation Vdrop- Tt and the calculation of heat balance of the electrode. Using the method, the optimum electrode size was designed for 2, 000A, for example, the length 6mm and the diameter 16mm were obtained.

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In order to produce large-diameter uniform plasmas, we have proposed two plasma sources; a plane electron-cyclotronresonance (ECR) slotted antenna (PESA) source for the ECR plasma production and a modified magnetron-typed (MMT) radio frequency (RF) source for the RF plasma production. The PESA has magnet rings behind the slotted antenna to provide magnetic field for the ECR. The MMT RF source provides high density uniform plasmas with a help of the LC resonance of auxiliary electrode placed parallel to the substrate. Both plasma sources produce large-diameter uniform plasmas over more than 30 cm in diameter.
We have proposed a grid method for electron temperature control. By applying a negative dc voltage to the grid which separates a plasma processing region from a plasma production region, the electron temperature is decreased by one or two orders of magnitude in the processing region. The same effect is obtained by changing mesh size of a floating grid. The change of a slit between two grids also causes a variation of the electron temperature. These techniques are quite effective for a chemical reaction control in processing plasmas.

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The effect of the axial gas flow-rate on the characteristics of torch plasma, which is a DC arc plasma produced by a transferred type torch, has been investigated. The voltage gradient of torch plasma is about 2-4V/cm. It increases with the axial gas flow-rate and decreases with the current. However, it becomes constant near a current of 200 A and an axial gas flow-rate of 4Nl/min. The central temperature of torch plasma is not affected by the axial gas flow-rate and increases with the current. The radial temperature distribution becomes flatter when the current increases and the axial gas flowrate decreases.

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Cross-sectional area and current density of a transient glow discharge have been investigated in nitrogen after static breakdown. To measure the cross-sectional area of the transient glow discharge, the image converter camera is used with the framing mode. The measurements have been made for 5.0mm gap length at gas pressures of 80-160Torr. The results show that the cross-sectional area decreases with increasing gas pressure. At constant gas pressure, the cross-sectional area decreases with increasing the circuit resistance and increases in proportion to the discharge current. The current density of the transient glow discharge is proportional to the approximate square of pressure and independent of the resistance. These characteristics are similar to those of normal glow of DC glow discharge at low pressure.

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In general, electron energy distribution (EED) functions in weakly ionized gases are deduced by a Monte-Carlo simulation (MCS) or a. Boltzmann equation analysis (BEA) using a, set of electron collision cross section which describe the occurrence probabilities of two body collisions between electron and atom or molecule.
This paper presents the results of detailed MCS and discussions on the position depended EED in non-equilibrium regionn of steady state Townsend discharge. Calculations are carried out in Ne and Ar at 5 Torr and E/p0=10 V/cm-Torr conditions.
It is concluded that relaxation and fine structures of EED are caused by not only the inelastic collision but also the elastic collision with Ne and Ar.

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The detecting device and the reflection characteristics of the inspected object play an important part in automatic inspection systems. The relations among the detecting lens, the surface roughness, and the reflectances of the inspected object in automatic inspection system are studied by means of Monte Carlo (MC) method in this paper. The automatic inspection system of IC production is taken as the simulation model. Theoretical analysis and simulation results reveal as follows: It is available to examine the relation between the detecting device and the reflection characteristics of the inspected object in an automatic inspection system by MC simulation method. If the inspected objects have the same reflectance and surface roughness, the number of reflection photon bundles is related to the radius of the detecting lens and the shape of the inspected object. A change in specular reflectance can affect the reflection photon bundles much more than that of diffuse reflectance. But with the increasing of the surface roughness, the photon bundles received by the lens decrease, and the influence of specular reflectance on the reflection photon bundles tends to become the same as that of diffuse reflectance.

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A model for partial discharge (PD) propagation in a single channel of an electrical tree is proposed. PD is induced by the high field near the needle tip, then propagates along the channel by field enhancement due to charge injection by PD, and stops propagating when the field becomes less than a certain value due to field divergence. This model suggests that the field distribution and the tree growth process are closely related to the behavior of PD. By considering the influences of gas pressure and the applied-voltage frequency on the behavior of PD, various phenomena of tree growth, such as the bush formation under higher gas pressure and low frequency, are qualitatively explained. This model also suggests a relation between PD and the fractal nature of treeing breakdown.

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Cathodoluminescence (CL) obtained from the surface of chemical vapor deposited diamond is studied. The foreign adsorbed atoms of diamond surfaces vary not only the electrical properties but also CL properties. CL intensity of oxidized surface is lower than that of hydrogenated surface because the existence of surface states promote the surface recombination of electrons and holes. However, it is also shown that fluorination of the oxidized surface recovers the CL intensity of diamond surface through reduction of surface states.

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SrAl₂O₄ activated with Eu, one of new fluorescent materials with long decay time, was deposited on Si substrates using an RF sputtering technique with facing targets. The as-deposited films did not show any peaks in the X-ray diffraction spectra or the photoluminescence was not observed. However, the X-ray diffraction peaks and a photoluminescent peak at about 520nm were observed after annealing in a reducing Ar+H2 gas and an inert Ar gas. The structure of the sputtered films was investigated using EDS and SEM. The thermoluminescence peaks were observed, and the lifetime of the fluorescence and the activation energies were calculated from the peaks. The results in this work are useful for the future applications.

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The bulk-type YBCO superconductor prepared by the MPMG process characterizes high critical current density Jc over 3×104A/cm2 at 77K and 1T. Therefore it is expected to be applied to various fields such as magnetic bearing, magnetic levitation, flywheel for electricity storage, and etc.. In these applications, evaluation of magnetic characteristics of the high-Tc superconductor is an important problem. It is necessary to value not only DC magnetic properties but also AC magnetic properties. Especially, in real applications it is important to value the AC quench properties of it. So we had developed the magnetic field visualization system, which enables measurement of magnetic field using a Hall device and produced the visual images of magnetic field on a computer display. We measured the AC quench properties of the YBCO ring specimen under the AC magnetic field with the frequency of 50Hz. From the experimental results we can understand that the superconductor results in the quench by the heat under the some AC magnetic fields, and that the quench properties of the ring specimen are ruled by its weak links.

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The magnetic properties of electrical steel sheets and plates at high flux density near saturation magnetization were investigated. The sheets and plates have nearly the same magnetization curves as theoretical ones calculated with magnetic anisotropy and magnetization rotation. The slopes of iron losses to flux density on log scales are almost constant at high sinusoidal flux density. Those of hysteresis losses are almost two and also those of eddy current losses to effective flux density obtained from induced voltages are also constant near saturation magnetization.

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Thermally stimulated currents (TSC) have been measured in undoped polyaniline film at various heating rates. Main TSC peak measured around 170K at the heating rate of 0.033K/s was separated to three single TSC curves by the proposed auto-separation method. The separated main peak evaluated as about 0.14 eV did not depend on collecting fields, but increased considerably by increasing heating rates. These results suggest the possibility of sure structual change of molecular arrangements.

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We present a possible suggestion method to measure a permittivity of material without cutting a sample by means of the rectangular cavity resonator. A theoretical discussion on the possibility is given in this paper by studying the relationship between the material permittivity and a resonance frequency of the electromagnetic field inside cavity which is calculated by the FDTD method. We show the permittivity measurement chart by which the permittivity can be estimated from the measured resonant frequency. The permittivity estimated has a reasonable agreement with an empirical value within an error of several percents. The present result supports the validity of the present method.

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In the present paper, MIM structures of [Al/polyimide LB film/Au] were investigated. These structures were prepared in 1986, about ten years ago. Current versus voltage characteristics of structures were investigated by application of various voltages from a battery. It was found that current was negative by applying positive voltage. That is, current of -1×10-13 A was measured in application of voltage of above (+0-400)mV. Such a characteristic shows that the MIM structure supplys electrical energy to the battery, so MIM are electrical source. Furthermore, mechanism of MIM electrical source is iscussed.

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