Showing papers by "Akira Kinbara published in 1993"
TL;DR: In this article, the durability of several dielectric materials used for RF windows is discussed in terms of secondary electron emission (SEE), cathodoluminescence, and Dielectric loss.
Abstract: The breakdown of RF windows used in high-power klystrons is one of the most serious problems in the development of klystrons. The durability of several dielectric materials used for RF windows is discussed in terms of secondary electron emission (SEE), cathodoluminescence, and dielectric loss. High-power tests of these materials with TiN coatings, thus having low SEE, were also carried out using a traveling wave resonant ring. The results show that alumina ceramics are superior to sapphire and aluminum nitride. The origin of breakdown is investigated, and the requirements for RF window materials are presented. >
52 citations
TL;DR: The work functions of the LaB6 thin films fabricated at 300, 750 and 1000 K had values of 2.7 eV and 2.8 eV, respectively as discussed by the authors.
41 citations
TL;DR: In this article, the effect of plasma treatment using argon and oxygen discharge gases on the surface energy of PTFE foils was examined by measuring the contact angles of water droplets placed on the foil surface.
Abstract: PTFE foils were plasma-treated in order to enhance their adhesion to thin films The effect of plasma treatment using argon and oxygen discharge gases on the surface energy of PTFE foils was examined by measuring the contact angles of water droplets placed on the foil surface Exposure to the plasma for only about 10-20 s was very effective in enhancing the surface energy By depositing gold films onto the PTFE substrates, it was found that this enhancement in surface energy was directly related to an increase in the film adhesion It was also found that Ar plasma treatment of a few tens of seconds followed by O2 plasma treatment for 10 s was even more effective for adhesion enhancement
24 citations
TL;DR: In this article, scratch, peel, and pull methods for adhesion measurement were applied to deposited thin film/solid substrate combinations, and the role of ion bombardment in improving adhesion was considered.
Abstract: Scratch, peel, and pull methods for adhesion measurement were applied to deposited thin film/solid substrate combinations. Scatter in the experimental data was observed and its origin is discussed. The interface between the thin film and the substrate was investigated by transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and Auger electron spectroscopy (AES), and the correlation of the interface structure with the adhesion strength was investigated. Ion bombardment and heat treatment were carried out to enhance the adhesion. Accumulation of bombarding gas ions at the interface was observed and the role of ion bombardment in improving adhesion is considered.
15 citations
TL;DR: In this paper, the authors investigated the effect of the cathodic voltage on the adhesion of Ni(100)-1000 nm/Ti(250 nm) films to Si(100) surfaces.
Abstract: Ni(100–1000 nm)/Ti(250 nm) films were prepared by dc planar magnetron sputtering on Si(100) surfaces. Interface structures between Ti and Si and adhesion of the Ti films to Si after different surface pretreatments have been investigated. Before the film deposition, the Si substrate received an Ar ion bombardment or a chemical etching treatment. In the case of the Ar ion bombardment, we have investigated the effect of the cathodic voltage. A low cathodic voltage (50 V) resulted in high adhesion. The results by Rutherford backscattering spectroscopy showed that the amount of Ar incorporated in the Si surface during the Ar ion bombardment is increased with the cathodic voltage. The existence of Ar at the interface between the Si substrate and the Ti–Si mixed layer seems to lower the adhesion. In the case of the chemical pretreatment, we have investigated the effect of the exposure time in the atmosphere after the chemical etching treatment. A shorter exposure time (within 1 h) has been found to be preferred ...
13 citations
TL;DR: In this article, a magnetron sputtering target and a LaB6 target and Ar discharge gas were used to produce thin LaBx thin films, and the composition of the films was investigated by the ICP method.
11 citations
TL;DR: In this article, the authors investigated the interface structure and adhesion of the Ti films on Si substrates pretreated by an Ar ion bombardment and showed that the adhesion was increased by the heat treatment at 723 K for 30 min, and the peeling ratio was reduced to about 10%.
9 citations
TL;DR: In this article, the role of energetic ion on the growth of crystalline phases of TiO2 thin films, applied substrate biases during deposition, were characterized using X-ray diffractometry and related to the optical properties of the films.
Abstract: Titania thin films grown by reactive bias sputtering were characterized. In order to investigate the role of energetic ion on the growth of crystalline phases of TiO2 thin films, we applied substrate biases during deposition. The structural properties were analyzed using X-ray diffractometry (XRD), and related to the optical properties of the films. The atomic composition was determined using Rutherford backscattering spectrometry (RBS). Negative substrate bias, Vb, showed a significant influence on the phase formed composition and microstructure: Vb in the range of 15 and 60 V enhanced the growth of crystalline phases and the rutile dominated the phase composition. However, the quantity of rutile decreased when Vb was raised to 100 V. The excess of oxygen was shown in the films by RBS.
7 citations
TL;DR: In this article, electric self-bias potential and its distribution on the radio frequency (RF) electrode in an rf plasma have been measured using probes buried in the electrode.
Abstract: Electric self‐bias potential and its distribution on the radio frequency (rf) electrode in an rf plasma have been measured using probes buried in the electrode. The potential increases almost proportionally with the net rf power (Wrf) ranging from 5 to 80 W. When the magnetic field parallel to the electrode (Wrf=26 W) is applied, the potential is reduced from −150 V (0 T) to −50 V (0.04 T) at the center of the electrode and the gradient in the potential distribution occurs along the E×B direction. This mechanism, the role of the external magnetic field, and the industrial applicability are discussed.
5 citations
TL;DR: In this paper, the self bias potential induced on an RF-powdered electrode (153 mm O) in a plasma is measured using electrical probes which are buried in, de-insulated from, and RF-connected to the electrode.
1 citations
TL;DR: In this paper, the interface structure and adhesion between a Si substrate after an Ar ion bombardment pretreatment and Ni(100-1500 nm)/Ti(250 nm) double layers prepared in a dc magnetron sputtering apparatus have been investigated.
Abstract: Interface structure and adhesion between a Si substrate after an Ar ion bombardment pretreatment and Ni(100–1500 nm)/Ti(250 nm) double layers prepared in a dc magnetron sputtering apparatus have been investigated. Two extra layers were generated between the Ti layer and the Si substrate in as-deposited condition. One was an amorphous Si (a-Si) layer(∼ 2 nm) formed on the single crystal Si substrate surface which contains Ar atoms. Another is an amorphous Ti-Si (a-Ti · Si) mixed layer( ∼ 3 nm) on the a-Si layer. A peeling test with an adhesive tape showed that the peeling occurred at the interface between the a-Si and the a-Ti · Si. Ar atoms appeared to be distributed at the interface and the direct contact of the a-Ti · Si layer with the Si substrate seems to be prevented. After preparing the film and subjecting it to heat treatment at 623 K for 30 min, the adhesion decreased by the accumulation of Ar atoms at the interface. At 723 K for 30 min treatment, however, the adhesion increased probably because of Ar atoms diffusion. It is considered that the Ar atoms incorporated at the interface plays an important role on adhesion of the layer.