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The defects and contaminants on a photo mask can seriously impact the yield of manufacturing devices in semiconductor
and flat panel display fabrication. Actually, as the device size and line width shrink in ultra large scale integrated (ULSI)
circuit technology, even tiny amount of haze defects on the photo mask may cause device failure. Especially, in ArF
lithography era, haze problem which is caused by deep ultra violet (DUV) laser beam exposure of have more serious
effects to the quality and productivity of photo mask than in former lithography generation using a KrF excimer laser.
Because the photon energy of ArF excimer laser is much higher than that of KrF excimer laser, ArF excimer laser can
more easily accelerate the photo-chemical reactions generating a haze defect on the photo mask between laser exposure
beam and thin metallic film on the photo mask. In general, photochemical effects can occur whenever the energy of a
single photon exceeds the dissociation energy for a component of the material. For example, the photon energy of the
ArF excimer laser which has 193 nm wavelengths is approximately 6.4 eV and this photon energy can break the
chemical single bonds of pellicle film of photo mask. It is widely known that the formation of haze defect depends on
laser wavelength, accumulated energy density onto the photo mask, a kind and concentration of surrounding gases,
humidity and cleaning method. Although many researchers have reported on efforts to find out the alternative improving
the photo mask quality, reducing residual contamination level and revealing the exact cause of the haze generation on the
photo mask, however performance improvement of such efforts has been difficult to measure. Typically test for haze
generation and inspection by using production lithography system takes much time as well as this process is too
expensive and risky. Accordingly Kornic Systems has developed and implemented laser induced haze acceleration
system. This system can provide the solution to reduce of haze generation time and to reveal which factor make the haze
onto the photo mask during lithography process. In this paper, we also introduce a practical ArF excimer laser system for
accelerating the haze formation and simultaneously revealing the detrimental effects of haze generation on the photo
mask in lithography process. The haze acceleration system which can control the accumulated energy density on the
photo mask level, humidity, temperature and concentration of gases such as NH3 and SO2 in process chamber, could be
an effective tool for providing technical and economical benefits to the photo mask and device manufacturers.
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