Copper metal resistivity

A typical feature of metals is that the lower the temperature the lower is the resistivity (Figure 16.1). For gold, silver, and copper metal, resistivity ranges between 10" -3 X 10" Q. cm (10 -3 X 10 Q m) at room temperature. For graphite the resistivity is 0.3 Q, cm. The electron-nuclear (electron-phonon) interactions are responsible for the resistivity. 

Copper and copper alloys resist corrosion by most food products. Traces of copper may be dissolved and affect taste or metals are often tin coated. 

Copper is resistant to oxidation, but over the course of time the metal acquires a coating of green corrosion called patina. The green compound is a mixed salt of Cu , hydroxide, sulfate, and carbonate that is formed by air oxidation in the presence of carbon dioxide and small amounts of sulfur dioxide ... 

In microbes without a permeability barrier, or when the barrier fails, a mechanism must be in place to export metals from the cytoplasm. These active transport systems involve energy-dependent, membrane-bound efflux pumps that can be encoded by either chromosomal- or plasmid-borne genes. Active transport is the most well-studied metal resistance mechanism. Some of these include the ars operon for exporting arsenic from E. coli, the cad system for exporting cadmium from Staphylococcus aureus, and the cop operon for removing excess copper from Enterococcus hiraeP i9A0... 

Moreover, the use of resistant strains is of interest. Slama et al. [21] described a heavy metal resistant BOD-sensor using Alcaligenes eufrop/jus, which contains plasmids encoding resistance to nickel, copper, cadmium, and zinc. An arsenic resistant BOD-sensor based on Pseudomonas putida was developed by Ohki et al. [35]. Another interesting possibility is the elimination of heavy metals by covering the BOD-sensor with a poly(4-vinylpyridine)-coated polycarbonate membrane [36] or polyfsodium styrene sulfonate) [62]. 

The majority of the following qualitative results were recorded by G. Gore,18 or by H. Moissan. Hydrofluoric acid attacks nearly all the metals—gold and platinum metals resist attack copper and silver are slowly attacked iron and zinc are rapidly dissolved. A mixture of hy-... 

In corrosion the dynamic electrochemical processes are of importance and hence considerations of the consequences of perturbation of a system at equilibrium are considered. Let us consider the familiar Daniel cell consisting of copper metal in copper sulfate, and zinc metal in zinc sulfate solution. This, as depicted in Figure 1.18 gives an electromotive force of 1.1 V when there is no current flow. When a small current flows through the resistance R, the potential decreases below 1.1 V. On continued flow of current, the potential difference between the electrodes approaches a value near zero, and... 

Because protein and cellulosic fibers are buried in contact with copper metal objects, a chemical microsystem is established whereby the degradation of the fiber and the corrosion of the metal interact physically and chemically. As the corrosion solution impregnates and swells the fibers, polymer molecules in amorphous areas are spread apart but are prevented from complete dissolution by the resistant crystalline segments. Copper ion from the corrosion solution is bound to the polymers (Figure 5). As the fiber degrades and more end groups are formed, more copper is bound. Polymers expand further apart as interchain forces are reduced. 

Aluminum metallization 1961 Copper metallization 2001 Lower interconnect resistance electromigration... 

Other popular alloys of beryllium are those with copper metal. Copper-beryllium alloys contain about 2 percent beryllium. They conduct heat and electricity almost as well as pure copper but are stronger, harder, and more resistant to fatigue (wearing out) and corrosion (rusting). These alloys are used in circuit boards, radar, computers, home appliances, aerospace applications, automatic systems in factories, automobiles, aircraft landing systems, oil and gas drilling equipment, and heavy machinery. 

A copper-plating electrolyte, specifically optimized for copper metallization of interconnects on silicon wafers is described. The copper sulfate based electrolyte features no (or tow) sulfuric acid and a high (>0.8 M) copper concentration. Elimination (or reduction) of the acid increases the electrolyte resistivity, thereby minimizing the... 

Copper is going to replace aluminum as the material of choice for semiconductor interconnects due to its low electrical resistance and high electromigration resistance (1-4). An inlaid interconnect is used for copper metallization in which the insulating dielectric material is deposited first, trenches and vias are formed by patterning and selective dielectric etching, and then diffusion barrier and copper seed layer are deposited into the trenches and vias (5). 

The objective of this research work is to develop a highly conductive copper alloy based diffusion barrier for copper metallization. The criteria for selection was that minimal increase in resistivity resulted on addition of one atomic percent of second element to copper. The copper-1 at.% zinc alloy conforms to this criteria and hence was selected as a candidate material for further study. Pure copper can easily be electroplated from simple acid copper baths, but the alloys of copper are more difficult when the deposition potential of individual elements is widely separated as in the present case. A Cu-Zn alloy can be deposited from baths containing coordinating agents. Having established that a Cu-Zn alloy can be successfully electroplated, an alloy of composition Cu-3.5%Zn was sputter deposited to develop an MOS capacitor and electrical testing was performed on as-sputtered and annealed samples. The bias temperature stability tests indicate that the alloy possesses promising diffusion barrier properties. 

We have already indicated in [2], that such interconnects outclass conventional copper metallization at this reduced dimension with respect to electrical resistance and current carrying capacity. 

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