NSR SF100 i-line Stepper with Scan Field (November 29, 1999)
The NSR-SF100 is designed to realize superior cost performance in a mix and match strategy with Nikon KrF excimer laser scanners, which are now the main systems in state-of-the-art fab lines.
The NSR-SF100 achieves a high resolution of 0.4 um or smaller and a 1 / 4 reduction ratio on an exposure field of 25 x 33 mm-the largest in the industry.
The new i(I)-line stepper also boasts a high throughput of 120 or more wafers/hour for 200 mm wafers. In addition, the new system is compliant with full-scale 300 mm wafer fab lines, which are expected to be built in 2001.
Development Background
Because the density of VSLI increases constantly, as soon as we started the mass production of 128 Mb DRAMs, we were already moving toward the volume production of 256 Mb devices.
A leader in this trend, Nikon unveiled the world's first KrF excimer laser scanner, the NSR-S201A, in April 1995.
And currently, with the industry accelerating from 0.18 um to 0.15 um applications, we are marketing the KrF excimer laser scanners NSR-S204B and NSR-S203B, which meet the demands of the tighter design rules and have thus become the preferred systems on the most advanced fab line.
In our standard "mix and match" approach, Nikon systems that are used for non-critical layers can perform up to the critical layers in the i-line range with a 0.35 um or better resolution.
These systems include the i-line stepper NSR-2205i14E, with a 22x22 mm exposure field and a 1/5 reduction ratio, and the i-line scanner NSR-S103B, with a 25x33 mm exposure field and a 1/4 reduction ratio.
The NSR-SF100 we are announcing today is a new i-line stepper for non-critical layers. The system was developed to work in a mix and match with KrF excimer laser scanners in leading-edge semiconductor production lines.
The NSR-SF100 is optimized for exposing non-critical layers, which comprise about half of the total (20 or so) layers in a chip. In addition to sharing the same reduction ratio and exposure field size as those of the KrF excimer laser scanner, the NSR-SF100 attains the resolution and high throughput to create the requisite total balance and superior cost performance for the mix and match formation.
It is a combination that will contribute to improving productivity and reducing the total investment cost of production lines.
Main Features
- Wide Exposure Field, High Resolution, and High Throughput
At 25x33 mm, the NSR-SF100 not only has secured the same large exposure field as a scanner for a step-and-repeat system, it has realized a sub 0.4 um resolution as well.
Furthermore, the new system achieves the high throughput of 120 or more wafers / hour for 200 mm wafer processing. - Optimized for Mix and Match
In addition to having full operation compatibility with the KrF excimer laser scanners NSR-S204B and NSR-S203B, the NSR-SF100 also has reticle compatibility with the i-line scanner NSR-S103B.
Looking toward the future, the NSR-SF100 can be utilized for non-critical layers in a mix and match system when fab lines move beyond 0.18 um applications to 0.15 um chips, when the ArF excimer laser scanner is deployed in mass production, and when fab lines produce 0.13 um devices around 2002. - Ready for 300 mm Wafers
The NSR-SF100 design predicts the line configuration for 2001 and beyond, and responds with a high throughput of 80 plus wafers/hour on full-scale production lines using 300 mm wafers.
Furthermore, since the NSR-SF100 can be upgraded from 200 mm wafer applications, the system can be made ready if a 200 mm wafer line is converted for 300 mm wafers in the future.
Nikon Precision Inc., 1399 Shoreway Rd., Belmont, CA 94002-4107. Tel: 650-378-8435; Fax: 650-508-4600.