KLA-Tencor and Nikon Develop Automated Overlay Correction Tools for Cost-Effective Mix & Match 45nm Lithography

SAN JOSE, Calif.--(BUSINESS WIRE)--

KLA-Tencor, Inc. (NASDAQ:KLAC) and Nikon Corporation have collaborated to develop a set of fully automated overlay correction control system tools, called Scanner Match Maker (SMM), that chipmakers can use to correct overlay errors common to "mix and match" lithography strategies which use lithography tools of varying capabilities and from different suppliers. The SMM technology is aimed at elevating performance of all scanners, enabling chipmakers to reduce their dedication of leading-edge scanners to specific layers, thus cutting overall lithography tool costs at more advanced nodes and extending the lifetime of lithography tools.

"Because there are no automated correction systems commercially available for distortion control, KLA-Tencor and Nikon have each developed a complementary set of tools to enable a direct scanner-to-metrology system link for automating mix and match overlay control," noted Ofer Greenberger, vice president and general manager of KLA-Tencor's Overlay Metrology group. "KLA-Tencor and Nikon will sell their respective correction tools directly to customers. This system is intended to be an open solution, enabling connection with scanners from other suppliers in the future. For this reason, SMM has a built-in security system to protect each scanner suppliers' proprietary information."

For most chipmakers, the high cost of latest-generation lithography tools prohibits use of the most advanced scanners on non-critical layers, resulting in different layers being exposed with different tools. Each lithography tool has a different field distortion signature that, at the small dimensions of 45nm and beyond, can cause significant overlay error. With the fully automated procedure of SMM, different illumination conditions and combinations of multiple scanners can be tightly controlled, improving productivity, operating efficiency and cost of ownership in environments using a mix of immersion and dry tools, as well as leading-edge and non-leading edge tools.

Toshikazu Umatate, General Manager of Development Headquarters, Nikon Precision Company, said, "Today, chipmakers' overlay budget has almost no margin of error with regard to scanner alignment performance. Mix and match methods can cause scanner fleet alignment performance to be less than half that of dedicated, single-tool overlay operations, and mixing scanners from different suppliers make these errors are even more significant. Our SMM toolset is intended to help customers implement sophisticated correction procedures that can overcome inherent overlay errors caused by differences in tool distortion signatures, making it much easier to match a fleet of lithography tools."

Currently under evaluation at a major semiconductor manufacturer in Japan and planned for release in the first calendar quarter of 2008, the SMM control system tools have demonstrated greater than 30% improvement in overlay accuracy vs. a mix and match technique without SMM.

Scanner Match Maker (SMM) Overlay Technology

The overlay correction procedure begins by using a common PM (planned maintenance) reticle to expose a reference wafer. The wafer is then measured by KLA-Tencor's Archer series of overlay metrology tools and analyzed by its KT Analyzer, which collects baseline distortion signature data. The overlay data is sent to the database server. At the same time, the scanner also sends exposure condition data that is associated with the overlay metrology data, including the machine name and illumination condition. With all these data, the SMM mix and match database is created automatically with strict user approval and security.

When a production lot arrives at the scanner, it requests current and previous processing layer information from the SMM database. The database server returns distortion and grid signatures from both layers. Although scanners have several functions to adjust stage grid and field distortion for matching based on PM procedures, it is not sufficient because a current layer usually has a different signature from the previous layer.

Using SMM, the scanner then adjusts the distortion and grid signature using Nikon's super distortion matching (SDM) and grid compensation matching (GCM) functions to match the target layer. (GCM controls the stage grid of a current layer on the scanner, so that the grid will match with the target layer's signature. SDM controls field distortion on a scanner's current layer, so that field distortion will match with the target layer signature.)

Testing at a major chipmaker has demonstrated greater than 30% improvement in overlay performance. Automating the procedure also increases accuracy and saves a significant amount of time. The SMM toolset enables not only mix and match among Nikon scanners but also enables mix and match with other suppliers' lithography tools enabling greater efficiency and flexibility.

About Nikon: Since 1980, Nikon Corporation has been revolutionizing lithography with innovative products and technologies. The company is a worldwide leader in lithography equipment for the microelectronics manufacturing industry with more than 7,800 exposure systems installed worldwide. Nikon offers the most extensive selection of production-class steppers and scanners in the industry. These products serve the semiconductor, flat panel display (LCD) and thin-film magnetic head (TFH) industries. More information about Nikon is available at www.nikon.co.jp.

About KLA-Tencor: KLA-Tencor is the world leader in yield management and process control solutions for semiconductor manufacturing and related industries. Headquartered in San Jose, California, the Company has sales and service offices around the world. An S&P 500 company, KLA-Tencor is traded on the NASDAQ Global Select Market under the symbol KLAC. Additional information about the Company is available at http://www.kla-tencor.com.

Source: KLA-Tencor, Inc.

Released December 7, 2007