July 1, 2005, Belmont, CA--Nikon Corporation has developed what is claimed to be the world's first lithography system with a 'hyper NA' lens (NA > 1). The NSR-S609B, an argon fluoride (ArF) immersion scanner with the industry's highest NA projection lens of 1.07, is targeted at mass production of 55 nm and development of 45 nm devices.
The system includes several new innovations, including the proprietary Nikon Local Fill Technology and a new Tandem Stage design, which enable the system to achieve extremely high throughput of 130 wafers or more per hour.
Nikon Local Fill Technology allows wafers to be processed at high scan speeds of 500 mm/sec or faster with no water spots or backside wafer contamination. A major concern of customers when discussing immersion lithography is micro bubbles. In repeated demonstrations, the Nikon Local Fill Technology has been proven to be free from micro bubbles and other immersion specific defects.
To increase throughput, improve accuracy, and enhance the long-term stability of the NSR-S609B, Nikon developed a new Tandem Stage design that utilizes two stages with different functions to optimize the performance of the tool for immersion lithography. The Exposure Stage is designed to process at very high rates, while the Calibration Stage is used to calibrate the tool between each wafer exchange. The result is a system with high throughput and improved accuracy. Alignment accuracy has been reduced to 7 nm or less with the Tandem Stage. Additionally, any risk of fluctuations or variations over time in the immersion process is eliminated by frequent calibration checks.
By equipping the system with POLANO, Nikon's advanced polarized illumination system, resolution of 50 nm for production applications can be achieved. POLANO improves image contrast by 20 percent, resulting in superior resolution, increased depth of focus, and improved critical dimension (CD) uniformity.