Lasertec Corporation has received an order for MPM157 (Phase shift mask measurement system with measurement wavelength of 157nm) from Selete (Semiconductor Leading Edge Technologies, Inc., in Yokohama, Japan). This is a new system that has been developed by combining the industry standard MPM193/248 with new technologies. As the design rule of semiconductor device is shrinking rapidly, the phase shift mask technology has become indispensable to make the size of patterns less than exposure wavelength. It is necessary to use the phase shift mask technique even in the early stages for F2 laser lithography with 157nm wavelength.
Comments
We started to provide a first phase shift mask measurement systems in 1993. Phase shift measurement needs to be done with the same wavelength as the one for wafer exposure. We have developed systems using 365nm, 248nm and 193nm, as the light source for lithography has evolved to shorter wavelength. This MPM series is now recognized as the industry standard.
MPM157 uses a F2 laser as the measurement light source, whose wavelength is 157nm and newly developed optics in addition to the technologies used for conventional and fundamental interferometer technique. The optical path for the light beam has been channeled through a vacuum chamber since the light of 157nm wavelength is absorbed by oxygen and moisture in the air.
Characteristics
- Usage of a high power and stable F2 laser makes it possible to perform accurate measurement with high speed.
- Measurement instability caused by turbulence is avoided by placing the interferometer in a vacuum chamber.
- Dust-free high accuracy linear motor stage
- Easy-to-use operation
Purposes
Phase shift measurement for phase shift mask
Key specification
Measurement accuracy : 0.2 degree
Measurement speed : Approximately 20 seconds / point
Mask size : 6025
Size and weight
Mainframe : W:1600 H:1500 D:1600 (mm)
Controller : W:860 H:1750 D:980 (mm)
Weight : 2500 (kg)
