Sputtering targets are value-added, engineered materials that serve as raw materials for the sputter deposition of a variety of high-performance thin films and coatings. For example, indium-tin oxide targets are sputtered to form transparent, conductive electrode films for liquid-crystal displays. Various target materials are used to sputter-deposit wavelength-selective multilayer coatings on architectural and automotive window glass. Sputtering targets made of high-purity aluminum, titanium, or refractory metals are sputtered to deposit conductive thin films on silicon wafers, forming the electrical connections between integrated-circuit (IC) devices.

There are no fundamental limitations on the types of materials that can be fabricated into sputtering targets and used to deposit thin films. Metal, ceramic, intermetallic, and semiconducting targets are produced in a variety of sizes and shapes, including planar, conical, and cylindrical geometries.
The most commonly used targets are circular or rectangular planar in shape and usually about a centimeter in thickness. Circular-planar targets ranging in diameter from about 15 cm to 35 cm are widely used to fabricate thin films in the microelectronics and data storage industries, while larger rectangular targets with lengths of one meter or more are used to coat window glass and flatpanel displays.

Business Communications Company recently completed a study assessing the current status of and future trends in target technology and applications, the structure of the industry, and world markets. The resulting report, Sputtering Targets and Sputtered Films: Technology and Markets, serves as the basis for the information presented in this article.

INDUSTRY STRUCTURE
The world's leading manufacturers of sputtering targets are headquartered in the United States, Germany, and Japan. The leading sputtering target manufacturers include Johnson Matthey Electronics (Spokane, Washington), Tosoh SMD (Grove City, Ohio), Japan Energy Corporation (Tokyo, Japan), Leybold Materials GmbH (Hanau, Germany), Materials Research Corporation (Orangeburg, New York), and W.C. Heraeus GmbH (Hanau, Germany).

Approximately 50 small- to mediumsized companies serve as manufacturers and/or distributors of sputtering targets in North America. Several hundred people are involved in the target activities (such as production, management, sales, etc.) of the largest companies in the industry.

All of the leading manufacturers have moved to establish multiple production plants and sales and service locations worldwide, increasing their geographic accessibility to their customers. Establishing a presence in Asia, particularly in the emerging markets of Korea, Singapore, and Taiwan, is of primary importance to the leading firms. These countries are playing host to a growing number of manufacturing plants for thinfilm-based products and, thus, present important new market opportunities for target manufacturers.

MARKET AND TECHNOLOGY TRENDS
Not surprisingly, trends in sputtering-target materials and sputter process technology reflect the evolving needs of the thin film industry. Integrated-circuit manufacturers are reacting to the emergence of copper films as a low resistivity alternative to sputtered aluminum interconnects. A variety of thin film display devices are competing in the flat panel display market to displace the bulky CRTs of desktop computers and televisions. In the data storage industry, the areal densities of magnetic hard disks continue to increase, and new optical disk formats are emerging. Consumer awareness of the cost savings associated with energy efficiency is driving new developments in optical coatings for windows.

These market trends are driving a number of technological changes in the sputtering industry. For example, higherpurity sputtering targets and new target materials are emerging to improve the performance of thin film products for certain applications. Also, sputtering target fabrication methods and cathode designs are being refined and optimized to improve target material utilization and process efficiency.

These and other technological trendscombined with anticipated growth in the production of thin-film devices and coated products for microelectronics, data storage, advanced display, and optical coatings applications-will prove to have a tremendous impact on the overall consumption of sputtering targets and sputtered films during the next five years.

WORLD MARKETS
In 1999, approximately 2.88 million kg of sputtering-target material were consumed to sputter-deposit 363 million M2 of thin films for microelectronics, data storage, advanced display, and optical coating applications. Sputtering is expected to remain a critical thin-film deposition technique in each of these market segments during the next five years. It is projected that worldwide production of sputtered films will increase at an average annual growth rate (AAGR) of 16% from 1999 to 2004, reaching 764 million M2 of sputter-deposited films in 2004.

Sputtering target consumption will rise at a slower rate than production of sputtered thin films during the next five years, due primarily to film thickness decreases in certain market segments and overall improvements in the utilization of target material. Currently, only about 25% of the target material is actually sputtered from the target during deposition due to limitations in cathode design. Sputtering-target end users are pushing for increases in this percentage due to their needs to improve process efficiency and cut costs. Overall, worldwide consumption of sputtering targets is projected to increase at a 6.0% AAGR during the forecast period (19992004), leading to a 2004 market size of 3.85 million kg.

In terms of target units, the worldwide market for sputtering targets totaled approximately 374,000 units in 1999. The target sizes that can be derived from these data represent values that are averaged over an extremely large range of target dimensions. A sputtering target used in production may vary in shape and size from less than 15 cm in diameter to as large as 3 m in length, depending on the application. In 2004, approximately 510,000 sputtering targets will be consumed worldwide, corresponding to a 6.4%-AAGR during the-forecast period.