Copper metallization technologies

System IV is a pretreatment technology for water containing cyanide and heavy metals including chromium, nickel, zinc, lead, cadmium, and copper. The technology precipitates a range of heavy metals there is no need to install separate pieces of equipment for individual metals. A cyanide treatment system expansion option is available for waste streams that also contain cyanide. System IV is not offered commercially. 

Anions travel toward the anode to balance the charges of the Zn2+ ions formed by the oxidation of the zinc electrode. Cations travel toward the cathode, to replace the charges of the Cu2+ ions that have been deposited as copper metal. Ions move between the two compartments (through the porous cup) to prevent the buildup of electrical charge inside the cell compartments and to complete the electrical circuit. Daniell s and his contemporaries inspiration to separate the half-reactions physically changed the course of technological history by making available portable sources of electricity. 

As you know from Chapter 4, solid solutions of metals are called alloys. Adding even small quantities of another element to a metal changes the properties of the metal. Technological advances throughout history have been linked closely to the discovery of new alloys. For example, bronze is an alloy of copper and tin. Bronze contains only about 10% tin, but it is much stronger than copper and more resistant to corrosion. Also, bronze can be melted in an ordinary fire so that castings can be made, as shown in Figure 8.3. 

In the future, the continued scale-down in ULSI features will need more stringent requirements with respect to the electrical conductivity of materials for the contacts and vias. Copper has higher electrical conductivity than aluminum. The future demand for tungsten hexafluoride will be affected by the improvement in tungsten metallization and the progress in the technology of copper metallization. 

Venkatesan S et al (1997) A high performance 1.8 V, 0.20 pm CMOS technology with copper metallization. In Technological digest, IEEE international electron devices meeting, 769-772... 

Rosenberg R et al (2000) Copper metallization for high performance silicon technology. Annu Rev Mat Sci 30 229-262... 

OCSM CSM (copper-stretch-metal)-technology battery... 

X. Lin and D. Pramanik, Future interconnect technologies and copper metallization, Solid State TechnoL, p. 63 (Oct. 1998). 

Figure 16.21 SEM micrograph of a cross section of a 90-nm technology node AMD microprocessor, with nine copper metal layers, fabricated with copper interconnect technology. (Reproduced with permission from AMD.)...

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