Hisashi Ohsaki

Global market and technology trends on coated glass for architectural, automotive and display applications

Deposition methods for large area coatings have been summarized from a production viewpoint, emphasizing mass productivity and flexibility. Market trends have been discussed and forecasts of the market movements of architectural, automotive and display applications are made. State-of-the-art technologies and the problems to be solved with these applications are detailed and possible solutions are also discussed.

High rate sputter deposition of TiO2 from TiO2−x target

Abstract A new sputter technique for high rate deposition of TiO2 was developed for applying to common planar magnetron sputter system. With this technique, using plasma sprayed TiO2−x targets and a sputter gas of a few percent of O2 diluted with Ar, TiO2 films are deposited with a high deposition rate efficiency (deposition rate per applied power density) being almost eight times larger than that of the conventional sputter method using Ti target and O2 sputter gas.

High rate deposition of TiO2 by DC sputtering of the TiO2-X target

Abstract A new sputter method for high rate deposition of TiO 2 was developed for application to the common planar magnetron sputter system. In this method, DC power is applied to plasma sprayed TiO 2− X targets using a sputter gas of a few percent of O 2 diluted with Ar and then TiO 2 films are deposited with a high deposition rate (eight times higher than that by the conventional method) and a good uniformity of thickness and refractive-index distribution.

TiO2−X sputter for high rate deposition of TiO2

Abstract A new sputter technique for high rate deposition of TiO2 was developed for applying to conventional planar magnetron DC sputter system. In this technique, TiO2 films are deposited by using a plasma-sprayed TiO2−X target and Ar sputter gas including a few percent of O2 gas. The deposition rate efficiency (deposition rate per applied power density) was almost 8 times larger than that of the conventional sputter method. This technique also has an advantage that there is no damage done to the under layer during the deposition. The Low-E coatings, being multi-stacks of Ag/TiO2, were obtained even in the case of no protective layer on Ag film and their optical properties were better than those of Low-E coatings including ZnO as the dielectric layer, because of the high refractive index of TiO2.

A new layer system of anti-reflective coating for cathode ray tubes

A new anti-reflective (AR) coating system, using an absorbing layer, has been developed for cathode ray tubes (CRTs). Theoretical analysis has revealed that the basic system needs only two layers to achieve zero reflection throughout the visible region if an ideal absorbing layer and a transparent layer are combined. The conditions for realizing the ideal AR property with two-layer system has been derived by numerical calculations. TiN x O y was chosen as the actual absorbing layer, while SiO 2 was chosen as the transparent layer. These choices are both based on theoretical and experimental considerations. The oxygen content in the TiN x O y film was found to play an important role on the AR properties, therefore a very thin (around 5 nm) SiN x barrier layer was deposited on the TiN x O y layer to prevent the oxidization of the TiN x O y during the subsequent deposition of SiO 2 . The insertion of such a thin SiN x layer was found to have almost no influence on the optical properties, therefore the system (Glass/TiN x O y /SiN x /SiO 2 ) can be called as two-layer system with a barrier layer. The AR properties and the electromagnetic shielding property (i.e. the electrical conductivity) of the coating was almost the same as the conventional transparent multilayer system which needs more than twice as thick as this system. This coating has been successfully adapted to the panel glass for CRTs on an industrial scale.

Structure of an extremely thin film of a-SiO2

Abstract By means of electron beam evaporation, we have succeeded inpreparing a substrate-free amorphous SiO 2 (a-SO 2 ) film 4A in thickness for electron diffraction study. The analysis of the diffraction intensity from the film has detected atomic distances of 1.54A and 2.48A as those of Si-0 bond distance and O--O distance; which are considerably shorter than Si O bond distance and O--O distance observed by X-ray diffraction in ordinary a-SO 2 : 1.62A and 2.65A. This result reveals that the structure of extremely thin a-SO 2 film is different from the bulk structure in a-SO 2 material.

18.3: A New Layer System for Wideband Anti-Reflection Coatings Designed for CRTs

A new AR coating using an absorbing layer has been developed for CRTs. Theoretical analysis has revealed that basic layer system needs only an “ideal” absorbing layer and SiO2. A Glass/TiNxOy/SiO2 layer system made by DC reactive sputtering exhibited wideband anti-reflection property as well as Iow sheet resistance comparable to conventional transparent multi-layer stacks. SiNx barrier layer inserted between TiNxOy and SiO2 layers made it durable against the heat treatment during CRT manufacturing process, which realized the commercialization of coated panel glass for CRTs with this layer system.

DC reactive sputtering of electro-conductive transparent tin suboxide using a Sn-O2/Ar system

Abstract Transparent thin films of tin suboxide with high electro-conductivity were prepared by DC reactive sputtering on a Sn-O2/Ar system without any dopant. The curves of current versus voltage applied to the tin target, the I-V curves, were observed to be continuous in this system and there was no avalanche-like state jump between the oxide and metal modes. The highly electro-conductive tin suboxide films were obtained in the transition mods and the conductivity changes in a Gaussian-like manner depending on the applied voltage. This profile shows that the deposited film changes from a well-oxidized tin oxide to a partially oxidized tin when the applied voltage is increased.

Shrinkage of atomic distances in ultrathin a-SiO2 film

Abstract Substrate-free a-SiO2 films, 480 A in thickness, have been made by means of electron beam evaporation. Electron diffraction patterns, taken under the condition that the incident beam is normal to the films, are all centre-symmetric, while their intensity features vary considerably with the film thickness. Since a film as thin as 4 A has fewer atomic pairs in a direction normal to the film than in the parallel direction, the Patterson function is not spherically symmetric as for a bulk sample but instead is cylindrically symmetric. A Fourier sine-transform of the intensity therefore no longer gives a proper radial distribution but one that depends on the film thickness. A procedure for correcting the modified function is derived. The obtained interatomic distances for the Si–O bond and O – O are respectively 1.54 and 2.48 A, for the film 4 A in thickness and are smaller than those of bulk a-SiO2. These results indicate that the Si-O and O – O atomic distances are lower at a surface and that the bo...

Bendable and temperable solar control glass

Abstract Bendable and temperable solar control glass with a basic layer construction of SnO 2 /SiN x /CrN x /SiN x /SnO 2 was produced by the dc reactive sputtering method. For protection of the CrN x layer from oxidation during heat treatment processes, thin buffer layers of SiN x were inserted between the CrN x layer and oxygen sources such as air and SnO 2 layers. It was found that the stoichiometric Si 3 N 4 with a minimum of impurities is a good buffer layer. The SnO 2 layer deposited on the transition mode indicated the lower oxygen diffusion coefficient and oxygen release property than one deposited on an oxide mode. The transition mode SnO 2 has, therefore, been proved to be suitable for the bendable and temperable solar control glass.