Nikon Step-and-Repeat Scanning System NSR-S204B New High-Throughput KrF Scanner

Main features :

The new Nikon Step-and-Repeat Scanning System NSR-S204B offers a 40 percent improvement in throughput over Nikon's third-generation scanner, along with extremely high resolution, and full support for 300-mm wafers.
In July of this year, Nikon will begin accepting orders for the tool, which is expected to sell for about 900 million Japanese yen.
Projected sales for the first year are 150 units.

The NSR-S204B will be able to process 120 or more standard 200-mm wafers per hour. This 40 percent improvement in throughput over the previous model is accomplished by increasing the stage scanning speed and reducing alignment time.
The tool will process approximately 75 of the larger 300-mm wafers per hour, a number equivalent to a 50 percent improvement in throughput, due to the greater number of chips on each wafer of this size.

The tool's alignment accuracy of 35 nanometers (M+3 sigma) also surpasses that of previous models.
Alignment accuracy expresses the precision with which the scanner exposes successive layers on the wafer.

The light source of the NSR-S204B is a KrF excimer laser with a wavelength of 248 nanometers.
The high-performance 0.68 N.A. reduction-projection lens installed in the tool allows it to achieve high resolution across a wide 25 by 33 millimeter exposure field. N.A. stands for numerical aperture, an index that expresses the amount of light that can pass through the lens.
With its high N.A., the lens of the NSR-S204B supports 180-nanometer design rules with conventional illumination, and can reach resolutions of 150 nanometers or better using modified illumination.

The high resolution of the NSR-S204B meets the demand for ever-increasing miniaturization of circuit features as mass production in the semiconductor industry moves from 64-Mbit DRAM to 128-Mbit DRAM chips, and eventually to 256-Mbit DRAM chips.
High resolution is also essential in making the powerful CPU chips used in today's personal computers.

The new scanning stepper will be fully suited to work in 300-mm wafer production facilities, which are expected go on line starting in 2001 A.D..
The NSR-S204B can be configured for either 200-mm or 300-mm wafers, depending on the user's needs.

The fourth generation NSR-S204B continues Nikon's successful series of NSR-S201A, NSR-S202A, and NSR-S203B scanning steppers, each of which marked a major advance in performance and reliability.
Scanning steppers are high-precision tools used in the semiconductor industry to reproduce microscopic patterns on silicon wafers that are made into computer chips.

In April 1995, Nikon introduced the NSR-S201A, the world's first scanning KrF excimer laser stepper designed to meet or exceed 250-nanometer design rules.
It was developed after extensive research showed that lens-based scanning steppers were the optimal solution to the dual demands for reduced feature size and larger exposure areas for semiconductor chips.
Since then, Nikon lens-based scanning steppers have won acclaim in semiconductor fabs worldwide, and a combined total of approximately 100 units has been shipped so far.

Overview of marketing plan :

Product name	Nikon step-and-repeat scanning systemNSR-S204B
When to start taking orders	1999-07
Planned number of units for sale	Approximately 150 units

Main Specifications :

Resolution	180 nm or better (Conventional) 150 nm or better (R.E.T.)
Light source	KrF excimer laser (wavelength : 248nm)
Reduction ratio	1 : 4
Exposure area	25 x 33mm
Total alignment accuracy	35nm or less (M + 3 sigma)
Thorughput	120 wafers / hour (200mm wafer) 75 wafers / hour (300mm wafer,approximately)

The export of this product is controlled by Japanese Foreign Exchange Trade Law and International export control regime. They shall not be exported without authorization from the appropriate governmental authorities. 1999-07