Proceedings Article | 26 March 2007
KEYWORDS: Semiconducting wafers, Calibration, Particles, Scanners, Immersion lithography, Bridges, Polarization, Lithographic illumination, Scanning electron microscopy, Wavefront aberrations
Nikon released the world's first hyper-NA immersion scanner, the NSR-S609B with NA 1.07 at the beginning of 2006.
With the highest NA lens using all-refractive optics, a flexible illumination system, and POLANOTM polarized
illumination, the NSR-S609B is capable of manufacturing devices with better than 55 nm resolution.
In addition, Nikon has announced the release of the NSR-S610C. With the world's highest NA lens (NA=1.30), the
S610C can comfortably achieve 45 nm critical layer volume production with k1=0.30. Nikon's proprietary catadipotric
lens design for the S610C provides the lowest flare and eliminates lens heating, resulting in stable imaging.
Because the S609B and the S610C are built on the same platform, a number of advantages can be realized. First, both
the S609B and the S610C utilize a tandem stage optimized for immersion lithography. The tandem stage consists of
separate exposure and calibration stages. This allows for continuous flow of immersion water, and for calibration of the
exposure tool during wafer exchange. As a result, throughput of greater than 130 wph is achieved, evaporative cooling
of the stage during wafer exchange is prevented, and focus drift, baseline changes, and other issues with tool stability
are eliminated. In this way, the tandem stage can achieve productivity and accuracy at the same time.
In addition to the calibration functions described above, the Integrated Projection Optics Tester (iPot) mounted on the
calibration stage can manage the long term performance of the projection optics. By measuring the wavefront
aberration, the polarization quality of POLANOTM, and the pupil fill, iPot supports the optimization of the imaging
performance. Nikon's polarized illumination system POLANOTM provides improved contrast with no loss of
illumination power. This provides increased process margin for 45 nm volume production using immersion lithography.
Finally, Nikon's proprietary local fill nozzle installed on the S609B and the S610C has been shown to eliminate
immersion defects from bubbles, watermarks, and particles.
Various data showing that the NSR-S609B meets requirements for 55nm and below production and the status of the
development of Nikon's newest immersion scanner NSR-S610C are introduced here.
