Vacuum sputtered films

The microscale friction and wear behavior of thin film of gold (Au) which was prepared in a vacuum sputtering apparatus was investigated. The substrate is Si(lOO) wafer. The film thickness is about 800 nm. For comparison, the microscale friction and wear of the substrate was also studied. 

Because of this ready adherence to a substrate, molybdenum disulphide films can be produced in a wide variety of different ways, including flotation from the surface of a liquid, spraying, brushing or dipping in a volatile dispersant, bonding with adhesive or polymeric compounds, rubbing with powder, transfer, and vacuum sputtering. The nature of the initial film produced depends on the way in which it is applied, and all the important types will be discussed in subsequent chapters. 

Except for the anomalous low friction reported for an ultra-pure sputtered film (see Section 10.5) and under radiation (see Section 7.4), typical minimum coefficients of friction in dry air or vacuum are 0.02 to 0.03. For fully disordered films in dry air the static coefficient of friction can be between 0.12 and 0.15, but because reorientation begins rapidly when movement starts any figures for the kinetic friction of disordered films must be suspect. 

Sputtered film load-carrying Complex equipment Vacuum... 

The basic Brophy and Ingraham technique was studied by several other authors. Bayer and Trivedi " found that the effectiveness of the technique depended more on the nature of the coating than on its thickness, and that retained moisture in the electroplate was essential for effective conversion. They recommended a current density of 21.5 A/m for 5 minutes to produce a coating thickness of 1.25 to 2.5 tjm. Nishimura and co-workers found that the presence of air or water or both in the conversion gas improved the wear life. Table 9.5 compares the properties of the in situ films with those of burnished and sputtered films, and shows superior wear life for the in situ films. Their friction results were curious, in that they found that the initial films which were formed gave low friction in air or nitrogen but not in vacuum. Low friction in vacuum was obtained when the initial product was heated in vacuum to 400°C. 

Sputtered Films require specialised equipment and experience for their production. They have excellent performance in vacuum, fair performance in dry or inert environments, and poor performance in air. However this is a technology which is rapidly developing, and improved performance in air is likely to be achieved reliably in future. 

Lightly-loaded rolling bearings in air to 350°C or in high vacuum (a) Burnished or sputtered films on races, cages and rolling elements (b) Composite retainers or land inserts, with lead on rolling elements or races... 

The electrode polarization could be reduced greatly by improving the electrode contacts with vacuum sputtered gold or silver powder films pressed on the pellets. Also, blocking the electrodes with thin mica sheets prevented the discharge of the cations and enabled us to recognize in our results the effects of the electrode polarization. 

The methods available for preparation of the different layers in thin-film solar cells include physical methods such as vacuum sputtering, vapor-phase deposition, and molecular beam epitaxy as well as chemical methods such as chemical vapor-phase deposition, metal organic vapor-phase epitaxy, chemical bath deposition (CBD), and electrochemical deposition (ED). This chapter explores the potential of electrodeposition as a route to the fabrication of absorber layers such as CdTe, CIGS, and CZTS for thin-film solar cells. Electrochemistry may also be usefiil for the preparation of transparent layers such as ZnO this topic has been reviewed by Pauporte and lincot [13]. 

Prior to sputtering, the chamber is evacuated to remove as much oxygen and moisture as possible. The level of vacuum that is achieved will depend on the effectiveness of the pumping system and the desired quality of the sputtered film. For high-quality film production, the pre-sputtering vacuum should be in the region of 10 Torr. Once this has been achieved, sputter gas (typically argon) is admitted to the chamber to raise the pressure to between 30 and... 

The chiral SAMs were prepared on ultra-flat gold surfaces. Gold films of 50 nm thickness were deposited on mica substrates using a high vacuum sputtering technique. The chiral... 

Films of rro, indium-tin oxide (80% In Oj), are transparent to visible light but not to infrared Hght (IR). In addition they have good electrical conductivity. Vacuum sputter deposihon of ITO affords excellent coahng uniformity and adhesion. Film thickness should be in the range 1000-2000 A for high IR reflechvity, but the thickness has little influence on film conductivity. 

The US Techni-Met Inc., has developed a process which may benefit some electronic applications where surface quality is paramount. The process involves the use of vacuum-sputtering technology and an acrylic monomer to lay down an acrylic polymer surface on film. The acrylic bonds to the film substrate by crosslinking and suitable films for the process include PET, PEN, PVC and polyimide. The company claims that its process confers superior water, oxygen and optical properties. 

Rhim, J.-W. Preparation and characterization of vacuum sputter silver coated PLA film. 

The method of deposition has been reported to have a large influence on the corrosion properties of permalloy [149-151]. In particular, plated permalloy films have been found to be more susceptible to corrosion than either bulk material or vacuum-deposited films of nominally the same composition. For instance, sputter-deposited permalloy was found to passivate in pH 2 solutions, but plated films did not [150]. Another study in neutral chloride solutions showed that plated permalloy had a lower pitting potential than bulk permalloy [151]. These reports suggested that plated films either have regions locally enriched in Fe or have a crystallographic orientation that is more susceptible to attack. However, little supporting evidence was provided. 

Preliminary experimenu suggest that an adherent vacuum-sputtered carbon film can be deposited on gold-electroded PVDF elements at a temperature below the depolariza-lion temperature. Thus, the combined goab of efficient electrical insulation, impermeability lo blood fluids, flexibility and fatigue resistance, and minimum interaction with surroundings cells may be achieved for inqrtaniable devices. 

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