Aluminium nitride films were deposited in a vacuum arc chamber with an aluminium cathode in nitrogen atmosphere. Process parameter was RF power output (0-400W), which was applied to the substrate. Chemical composition, surface appearance and crystallographic orientation of the films were measured.
The main results are as follows: (1) As the RF power output increases, self-bias voltage increases and Al atoms are sputtered from the film surface. (2) The chemical composition ratio of N to Al atoms of the film is 0.7-0.9. (3) In case of RF power output being less than 50W, the crystallographic orientation of AIN film is dominantly (002) which means the c-axis of AIN crystal is vertical to the substrate surface, and the film surface is rough. (4) In case of RF power output being more than 100W, the crystallographic orientation changes from (002) to (100) which means the c-axis of the crystal is parallel to the substrate surface, and the surface of the film becomes peeling off. The dependence of film properties on RF power output is considered to be due to ion's energy and sputtering.

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The formation of silicon oxide films by ECR plasma anodization, which is a low-temperature, dry anodizing method, with O₂, N₂O, and O₃ gases is reported from a view point of improving the anodizing efficiency and the anodized film quality. The active oxidizing species in anodization of Si was identified by analyzing the spectra of ECR plasma emission: plasma atomic oxygens play an important role in the anodizing process because the oxide growth rate strongly depends on the density of plasma atomic oxygen. The XPS and AES analysis revealed that the as-grown silicon oxide films anodized with N₂O and O₃ gases are the stoichiometric SiO₂ just as the silicon oxide film anodized in ECR plasma of O₂ gas. It was also indicated that there exists a quite thin SiO_x (0<x<2) layer between SiO₂ and Si, and that Si ions move across the layer to combine with negative oxygen ions at the SiO₂ SiO_x interface. From the C-V measurement of MOS capacitor fabricated with as-grown SiO₂ film, it was observed that the value of interface state density is almost the same as that grown by thermal oxidation. The value of interface state density slightly depends on types of oxidizing gas or its conditions, possibly due to the sputtering by plasma charged particles.

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It is confirmed, with the use of both a movable magnetic filter and a plasma grid, that plasma parameters (H₂-CH₄ or Ar-CH₄ plasmas) are spatially well controlled. At any filter position, plasma parameters change steeply across the magnetic filter. Then, a plasma source is divided into two parts, i. e. a source plasma region (high density plasma with energetic electrons) and a diffused plasma region (low density and low temperature plasma without energetic electrons). The former is suitable for producing the reactive species and the latter for preparing thin films. In addition, plasma parameters in the diffused plasma are controlled by changing the plasma grid potential. The role of the magnetic filter (i. e. preferential reflection of energetic electrons) is also discussed by computer simulation.

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Silicon oxide films have been deposited on unheated substrate by low frequency 50Hz plasma CVD using a nitric oxide (N₂O) and monosilane (SiH₄) mixture. To deposit high quality silicon oxide, the monosilane fraction in the nitric oxide and monosilane mixture has to be less than 30%. Characteristics of the silicon oxide films deposited on silicon wafer and glass plate were as follows. Refractive index of the silicon oxide films, resistivity and break-down field strength were about 1.5, 10¹⁵Ω•cm and about 10⁶V/cm, respectively. The grown films were highly transparent and showed very uniform interference color. Mechanism of the deposition of high quality silicon oxide is discussed on basis of the experimentally observed photo emission spectra from the low frequency plasma.

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The ion energy distribution in a medium-vacuum nitrogen arc plasma with a titanium cathode was measured using a Gridded Energy Analyzer. The parameters were pressure (0.1 to 2Pa) and distance from cathode, L, (155 to 380mm). The diameter and the length of the vacuum vessel were 400 and 600mm, respectively. The arc current was 50 A DC. The experimental results show that; the ion density decreases as the L increase, the maximum ion energy is about 60eV, the maximum probability energy of ions is 30eV for 0.1Pa whereas 0eV for 2Pa, and between these pressures it decreases with increasing L.
The existence of beam component of the ions is discussed. As a result, it is found that ion movement turns from beam-like to random as the pressure and the L increase.

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Recently, the neccessity of establishing the way to diagnose the deterioration of insulating materials and to predict the insulation breakdown becomes important.
In this paper, the insulating material with a small artificial void is used for experiments. The discharge pulses and the discharge luminescence measured simultaneously. The discharge luminescence is observed by a digital processing system. The discharge magnitude distribution was measured by a special internal discharge pulse measurement system which could analyze the discharge magnitude according to the phase angle domain of the applied AC 50Hz voltage. These measurements are carried out to correlate each other.
In results, the relation between discharge pulses and discharge luminescence is made clear. The pulse discharge magnitude near the positive peak of the applied voltage can be important factor on diagnosis of treeing deterioration.

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This experiment was carried out to investigate the effects of SrO, BaO and PbO substitution on the magnetic properties of anisotropic La system ferrite magnets. The compositions were chosen according to formula: (La₂0₃)_1-x(2MO)_x•nFe₂O₃, (MO=SrO, BaO, PbO) where X was varied between 0 and 1.0, and n between 12 and 6. The results are summarized as follows: (1) The magnetic properties of these magnets were apparently improved by substitution of SrO, BaO and PbO a part of the component oxide. (2) From X-ray diffraction analysis, the single phase of magnetoplumbite can be obtained by n=9 in the SrO, BaO and PbO (X=0.6-0.8) substituted system. (3) The optimum conditions of making magnets and some properties of a typical sample are the following: The chemical analysis composition was La³⁺_0.230Sr²⁺_0.883Fe²⁺_0.041Fe³⁺_11.974O₁₉. The semisintering condition was 1, 275°C for 1h in oxygen, and sintering condition 1, 250°C for 0.5h in oxygen. Magnetic and physical properties are J_m=0.44 T, J_r=0.42T, H_cJ=271.8kA/m, H_cB=257.8kA/m, (BH)_max=34.5kJ/m³, H_A=1, 596kA/m, K_A=3.35×105 J/m³, σ_s=89.0×10^-6Wb•m/kg and D=4.92Mg/m³.

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By utilizing the laser-induced-pressure-pulse (LIPP) technique, we quantitatively studied the behavior of space charge in low-density polyethylene (LDPE) and crosslinked polyethylene (XLPE) films in contact with metal or carbon-loaded semiconducting layers so as to clarify the space-charge characteristics in power cables.
Negative hetero space charge near the anode and positive space charge in the bulk were observed in unoxidized LDPE under the fields above 120kV/mm. The amount of negative space charge increased with applied field, while positive space charge in the bulk disappeared with increasing applied field. These indicate that electron injection and ionization are enhanced by applied field.
Prominent negative homo space charge was formed near the cathode in oxidized LDPE, indicating that oxidation enhanced electron injection. The depth of charge centroid from the cathodebecame larger with increasing temperature. This indicates that the effective electron mobility increases with temperature.
Negative space charge was also formed in the bulk in XLPE films with metal electrodes, indicating that crosslinking enhanced electron injection. XLPE films with a carbon-loaded semiconducting layer showed both negative and positive homo space charges near the semiconducting layers, indicating that both electrons and holes were injected from the semiconducting layer.

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