May, 2008
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Page 13
High-Purity Water Analytical Technology for Sub 50-nm Devices
By: Ikunori Yokoi, Ph.D., Tetsuo Mizuniwa, Ph.D., Hiroto Tokoshima, and Katsunobu Kitami
UP250413 		Abstract: Progress in the development of a semiconductor-scaling technology and that of high-performance microelectronics products have pushed requirements for high-purity water analytical measurement technology. According to the Wafer Environment Contamination Control (WECC) section of the International Technology Roadmap for Semiconductors (ITRS), it became necessary to control the metal content in high-purity water to <0.5 nanograms per liter (ng/L) in 2007 when the technology node shifted to hp65 from hp90. Moreover, the number of particles in high-purity water must be controlled to 33-nanometer (nm) particles, which is one-half the size of half pitch to <0.2 N/mL. Then, the new high-purity water analytical technology that measures metal to 0.1 ng/L, and the number of 20-nm particle will correspond to the technical demands of the current ITRS guidelines. An organic nitrogen compound is also reported with the analysis example. Furthermore, the relationship between high-purity water quality and the amount of wafer contamination also is reported.
Page 21
RO Technology and Recent Developments
By: Rajindar Singh
UP250421 		Abstract: Reverse osmosis (RO) is a continuous, steady state process that uses semi-permeable membranes for removing solutes such as dissolved ions from a solution. RO membranes allow the passage of water but reject almost all the ions and salts, resulting in a concentrated retentate, or reject on the feed side of the membrane, and product water or permeate on the other side of the membrane. Semi-permeable membranes permit preferential passage of certain solutes under the influence of a driving force; pressure difference between the feed side and the permeate side. Thus, most permeable components get enriched in the permeate stream, while the least permeable component gets enriched in the reject stream. The transport properties of solutes through the membrane are, thus, determined by the permeability of the membrane and by a driving force.
Page 31
Greenwater: A New Way for Defining Water Reuse
By: James P. Welch
UP250431 		Abstract: The water industry is now more adept at optimizing the integration of chemical and mechanical treatment into comprehensive water solutions. This drive to provide an optimized solution is being intersected by society’s increased water awareness and market forces that have invigorated resource conservation efforts. Water reuse is in its genesis; solution providers and endusers are endeavoring to expand their nascent understanding of reuse opportunities, to extend beyond the traditional ideas of “cycles of concentration” to increasingly complex concepts that prioritize competing projects for complex systems.
Page 38
Emerging Applications of High-Purity Water: Meeting Challenges of Advanced Semiconductor Manufacturing
By: Bipin Parekh, Ph.D.
UP250438 		Abstract: Wet cleaning processes continue to advance to meet the challenges of manufacturing semiconductor devices of ever-increasing performance and smaller geometries. The new materials, manufacturing processes, larger wafer size, aggressive dimension shrinks, and ESH (environmental, safety, and health) considerations will drive the development of new cleaning methods for both front-end-of-the-line (FEOL) and back-end-of-the-line (BEOL) cleaning processes. The role of high-purity water (deionized [DI] water) in these manufacturing processes is expanding from the traditional wafer rinsing to the more advanced applications.
Page 49
Purifying Water at the Georgia Aquarium
By: Trude Witham
UP250449 		Abstract: Aquarium fish need many things to survive; clean water is one of them. The Georgia Aquarium in Atlanta, among the world’s largest, has plenty of clean water for the more than 100,000 animals and fish that live there. The incoming city water must be treated before it can be used in the aquarium’s fresh and saltwater exhibits. The aquarium uses specialized high-purity water treatment equipment to remove chlorine, dissolved minerals, and organics from the main facility’s incoming water and the make-up water for all the fresh water exhibits.
Page 51
Overview of Report on Global Perspective of Low-Pressure Membranes
By: Mike Henley
UP250451 		Abstract: The National Water Research Institute has issued a new report (by D. Furukawa) that examines the worldwide use of low-pressure membranes. The study also examines the markets for such membranes that are used in water treatment. This article will summarize key points of the study and its view of the membrane market.