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In order to control pressure rise in a vacuum chamber, a radio-frequency magnetron cosputter deposition system has been developed and boron nitride and copper composite (BN/Cu) film was coated onto the inner surface of a vacuum chamber in the shape of a cylinder. Outgassing rate of the BN/Cu coated chamber was estimated with a pressure rise method to be about 5×10−12 Pa m s−1, which was two orders lower than that of the noncoated vacuum chamber in the same shape as the BN/Cu coated chamber. Mass spectra of the residual gas in the chamber indicated that the outgassing of various gas species, such as hydrogen gas, nitrogen gas, and oxygen gas, were reduced by the BN/Cu coating. These results concluded that the BN/Cu coating could control pressure rise in a vacuum chamber.

Low frictional coatings made of copper, boron nitride, and oxygen on a stainless steel substrate were synthesized by magnetron cosputter deposition combined with excimer laser irradiation. The frictional force of the coating films was observed by a system developed for measuring vacuum friction. The coating properties were also observed by a conventional contact angle measuring system, a scanning Auger electron spectrometer, and a Vickers hardness measuring system. The surface layer of the coating films was oxidized by the excimer laser irradiation. Surface energy and film hardness were also modified by the laser irradiation. Frictional coefficients as low as 0.075 were achieved after irradiating the films under ultrahigh vacuum conditions. Since these coating films have already been oxidized and irradiated with high energy UV light they will be applicable for aerospace coatings.

A technique to modify the interface after the formation of the interface is needed either because of some process requirement or because of a change in the required material function over time. In this article we present a novel technique to form an intermetallic compound at the interface between a coating layer and the substrate by depositing a specific metal film on the top of a coating layer. Based on the property of the intermetallic compound, the interface is modified. Experimentally, the diffusion and interfacial reaction of specimens with a top-film/middle-film/substrate structure were investigated. With proper choice of the top-film metal, the top-film metal diffuses inward without any significant reaction with the middle film and concentrates at the interface between the middle film and the substrate followed by formation of an intermetallic compound. We discuss conditions for obtaining the above phenomena and present a general guide for choosing the top-film metal. Key factors are (1) the segreg...

We studied surface segregation of substrate metal on the top of a deposited film in a vacuum. A metallic polycrystalline film of submicron or micrometer thickness was deposited on a substrate and heated in an Auger electron spectroscopy (AES) or x-ray photoelectron spectroscopy (XPS) apparatus. The surface composition was monitored during heating. The specimen was heated until the substrate metal was observed on the surface of the deposited film and the surface concentration of the substrate metal became saturated. The depth profile of the heated specimen was obtained by measuring AES/XPS with Ar ion etching. Al, Ti, Cr, Ni, Cu, Nb, and Fe were used as substrate materials and Al, Ti, Cr, Cu, Zr, Nb, and Fe were used as film materials. More than 25 combinations of film–substrate materials have been investigated. For some film–substrate combinations, substrate metal was observed on the surface by heating at rather low temperature and substrate metal was only observed at the surface (i.e., surface segregatio...

In 1994 the Science and Technology Agency of the Japanese Government launched a project to interconnect networks under various ministries and agencies. The project is called the Inter-Ministry Computer Network System (IMNet). As a site of IMNet we are implementing a network-oriented database for surface chemical analysis such as Auger electron spectroscopy and x-ray photoelectron spectroscopy spectra. To create a network-oriented database, the stored spectral data must be shared by the client’s computers. Therefore, spectral data must have a common format, and the energy and intensity scales should be calibrated. To achieve these objectives, the software named the “Common Data Processing System” has been created and is provided via the Internet. A workstation has been installed to store the spectral data acquired on different analysis machines via computer networks. In the future we hope that all computers used with surface analysis machines can be connected to the system so that every surface analyst wor...

Segregation phenomenon of substrate copper atoms onto rf sputter‐deposited titanium film was observed using Auger electron spectroscopy and x‐ray photoelectron spectroscopy. When the specimens were heated, Cu atom diffused onto the surface of Ti film from the substrate with the diffusion constant bigger than that of the bulk diffusion by three orders of magnitude. The surface concentration of Cu saturated at about 5%. If the segregated layer was removed by sputtering, the saturated Cu concentration on the surface was easily reformed by heating. The saturation concentration was constant at heating temperatures between 710 and 850 K. This was interpreted to mean that the saturated surface composition is thermodynamically achieved and is easy to reproduce. The binding energy of Cu 2p3/2 of the segregated Cu was 0.24 eV higher than that of the pure metal. The amount of the charge transfer from Cu to Ti was assumed to vary linearly with the chemical shift, and the decrease in the work function due to the segre...

The surface precipitation process of epitaxially grown graphite (0001) layers on the C‐doped Ni(111) surface has been investigated by in situ x‐ray photoemission spectroscopy measurements. Peak intensity measurements at various temperatures clarified the change of the carbon chemical state from the segregated carbon through the monolayer graphite to the multilayer graphite. The simple thickness estimation in the transition region from the monolayer graphite to the multilayer graphite indicates that once the estimated thickness is calibrated, controlling the thickness of the graphite thin film in the monolayer range by a precise adjustment of the temperature may be possible. Changes of the chemical states of carbon on the Ni(111) surface with temperature were clarified by high‐resolution measurements with a monochromated Al Kα source. From the observed chemical shift of the C 1s peaks, a negative charge transfer from the monolayer graphite to the substrate can be postulated. This C–Ni interaction is consid...

The common data processing system (Ver. 3.0), which is software for common handling of spectral data taken on different instruments, has been constructed using Visual Basic language under MS–Windows (3.1). This software is used to convert each file format to the common format proposed as ‘‘VAMAS–SCA Standard Data Transfer Format,’’ to obtain the characteristic parameters of one’s spectrometer by using standard spectra in the system, to calibrate a spectrum with those parameters, to analyze spectral data by proposed procedures, and to obtain correction factors from the database. The common data processing system is not commercially produced but should be created by all the scientists and engineers who have an interest in promoting surface analysis. The fruits of the VAMAS–SCA activities have been made available with this software.

The surface compositions of two types of stainless steels in vacuum were observed with AES and XPS at 1000–1100 K; a 304 stainless steel doped with nitrogen and boron (304‐NB) and a 304 stainless steel doped with nitrogen, boron, and cerium (304‐NBCe). The changes of surface compositions of these steels were compared with that of commercial 304 stainless steel. A thin layer of boron nitride came out from grain boundaries and spread over the surface of the 304‐NB, but did not uniformly cover the surface. The spreading mechanism of the boron nitride layer at the initial stage of heating can be explained by Avrami’s model. In the case of 304‐NBCe, a boron nitride layer almost uniformly covered the surface at the early stage of heating, and rendered the surface inert to the adsorption of carbon and oxygen. Therefore, the 304‐NBCe stainless steel is a candidate material for vacuum vessels.