Improved Image Contrast Achieves Half-Generation Advance in Resolution Announcing the Sale of the Polano Polarized Illumination Function for Nikon Step-and-Repeat Systems
November 30, 2004
SEM photo showing results of using the Polano polarized illumination function
(test pattern of 60nm Line & Space)
Nikon Corporation (Teruo Shimamura, President) is pleased to announce that it has developed POLANO*, a polarized illumination system that improves image contrast by 20 percent in order to realize a half-generation advance in resolution. Beginning in the Spring of 2005, plans are to offer POLANO as an option on the NSR-S308F, Nikon's latest model ArF excimer stepper, which will start shipping in December of 2004. POLANO will also be available for installation on the Nikon ArF immersion stepper, which will have an N.A. exceeding 1.0, and is slated to start shipping in the latter half of 2005.
- *POLANO: Polarization Optimization for Lithographic Advance in NSR Optics
Sales Summary
| Product name | Polano Polarized Illumination Function for Nikon Step-and-Repeat Systems |
|---|---|
| Price (excluding tax) | To Be Determined (sold as an option on the NSR-S308F) |
| Sales launch term | Spring of 2005 |
Development Background
As progress continues on increasing the speed and density of VLSI chips, the foundation of the IT revolution, there has also been a demand for ever-higher N.A. values for the projection lens installed in steppers.
Ordinary illumination light is composed of light that is randomly polarized in several directions. It includes s-polarized light, which increases image contrast, and p-polarized light, which degrades image contrast. As the N.A. of the lens increases, the adverse effect p-polarized light has on contrast tends to grow. If, in order to achieve a high-contrast image, only s-polarized light is used for exposure then exposure power declines and throughput suffers.
With the development of the POLANO polarized illumination function, Nikon has succeeded in changing illumination light into s-polarized light that boosts image contrast without losing exposure power. This technology improves image contrast by 20 percent in order to achieve a half-generation advance in resolution.
Demonstration experiments were completed in October of this year using an NSR-S307E ArF excimer stepper (N.A. 0.85), and techniques for measuring the degree of polarization have been developed. After further refinements, POLANO is scheduled to be available as an option on the NSR-S308F ArF excimer stepper (N.A. 0.92).
POLANO is also scheduled to be installed on ArF immersion steppers to even further improve the resolution and image contrast of those models.
Main Characteristics
- Improves Image Contrast 20 Percent
Illumination light is converted to high-contrast-enabling s-polarized light with no loss in exposure power. This boosts image contrast by approximately 20 percent while maintaining throughput.
- Resolution Limit Improved by Half-Generation
When the POLANO polarized illumination function is installed on an NSR-S308F ArF excimer stepper (N.A. 0.92), which has a resolution capability of 65 nm or better, the resolution capability of this model is improved to 60nm or better by a half-generation.
- Improves Pattern Uniformity by 20 Percent
Image contrast is improved, increasing the exposure margin and enhancing critical dimension uniformity, an important factor in LSI manufacturing, by approximately 20 percent.
- The information is current as of the date of publication. It is subject to change without notice.