Vapor-deposited metal

Surfaces. Essentially any electrically conductive surface can be electroplated, although special techniques may be required to make the surface electrically conductive. Many techniques ate used to metalline nonconductive surfaces. These are weU-covered ia the Hterature (3) and can range from coating with metallic-loaded paints or reduced-silver spray, to autocatalytic processes on tin—palladium activated surfaces or vapor-deposited metals. Preparation steps must be optimized and closely controlled for each substrate being electroplated. 

Many authors have used XPS to investigate the mechanisms by which vapor-deposited metals such as copper interact with the surfaces of polyimides. Chou and Tang [29] observed that only small changes occurred in the XPS line shapes after vapor deposition of copper on polyimide they suggested that no... 

Keywords Metal vapor deposition Metal-organic interface Molecular devices Molecular electronics Self-Assembled Monolayers... 

In a typical spectroelectrochemical measurement, an optically transparent electrode (OTE) is used and the UV/vis absorption spectrum (or absorbance) of the substance participating in the reaction is measured. Various types of OTE exist, for example (i) a plate (glass, quartz or plastic) coated either with an optically transparent vapor-deposited metal (Pt or Au) film or with an optically transparent conductive tin oxide film (Fig. 5.26), and (ii) a fine micromesh (40-800 wires/cm) of electrically conductive material (Pt or Au). The electrochemical cell may be either a thin-layer cell with a solution-layer thickness of less than 0.2 mm (Fig. 9.2(a)) or a cell with a solution layer of conventional thickness ( 1 cm, Fig. 9.2(b)). The advantage of the thin-layer cell is that the electrolysis is complete within a short time ( 30 s). On the other hand, the cell with conventional solution thickness has the advantage that mass transport in the solution near the electrode surface can be treated mathematically by the theory of semi-infinite linear diffusion. 

A. Pyrolysis and Chemical Vapor Deposition Metal Silicides. 107... 

The properties of the polyimide-metal interface are different depending on whether the polymer is applied to a metallic substrate or whether the metal is deposited on the polymer. That a different interfacial chemistry occurs in these two situations is clearly demonstrated by a greater adhesion strength for polyimide on a metal than for the metal on polyimide (8-91. It is extremely difficult, however, to prepare for study an ideal interface consisting of one or two monolayers of polyimide on a clean metal substrate. Therefore, most of the studies of the polyimide-metal interface are restricted those involving vapor-deposited metals on polyimide. 

In the present study we have used a thin, well-ordered atomically flat alumina film grown on a NiAl(llO) single crystal surface as a model support [27]. The atomic arrangement within line defects of this film have recently been investigated [28]. In addilion, Ihere exists a proposed structure of the film based on X-ray diffraction data which is controversially debated at the moment [29]. The structure and size of the oxide-supported metal particles were controlled utilizing nucleation and growth of vapor deposited metal atoms under ultrahigh vacuum conditions. 

B. de Boer et al.. Metallic contact formation for molecular electronics Interactions between vapor-deposited metals and self-assembled monolayers of conjugated mono-and dithiols, Langmuir, 20, 1539, 2004. 

WALKER AND RIES Adsorption on Vapor-Deposited Metals 299... 

An interesting alternative is pitting on thin vapor-deposited metal films such as A1 or Ni-20 Fe [23-25]. In this case, pitting leads to a rapid perforation of the film and a further circular growth. These two-dimensional pits lead to simpler relations for the accumulation of corrosion products in comparison to the hemispherical situation, i x is radius independent and proportional to /c,p instead of to Also in these cases, local current densities of up to (c,p = 100 A cm have been measured. 

In TSV, vertical micro through holes (vias) are chemically etched, mechanically drilled or laser drilled in the silicon die at the wafer level, then made electrically conductive by plating or vapor depositing metal conductors. The sidewalls of the vias, however, must first be insulated from the silicon. A dielectric film overlaid with conductive metal may be applied to the sidewalls or the exposed silicon may first be oxidized to isolate it from subsequent metallization. Connections within the chips are generally made between bond pads on one face of the die to a land on the opposite side. 

One type of commercial infrared polarizer is a wire grid construction that is compact in size and transmits polarized infrared radiation of very high quality. The wire grid polarizer is formed of uniformly spaced parallel fine strips of vapor deposited metal on a transparent substrate. 

Figure 5.5. Effect of adsorption of oxygen on the electrical resistance of a vapor-deposited metallic iron film. Oxygen admitted at 77 K. Electrical resistance measured at 77 K both before (°) and after heating to 273 K ( ) and also at 273 K (x).

The extent of oxygen adsorption can be determined more accurately with vapor-deposited metal films, since multilayer adsorption is difficult to measure using AES. The interaction of a vapor-deposited iron film with oxygen after exposure to a dose of oxygen at 77 K and subsequently raising the temperature to 273 K is presented in Fig. The effect on the electrical resistance of the... 

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