The study on causes and control methods of haze contamination

Haze is a kind of surface contamination on photomask and lithography optics that made by photochemical reaction. There are many problems in photomask manufacturing, inspection and lithography process because of slowly growing feature of haze. In the photolithography process, the wafer damage has been occurred due to the time dependent growth of haze. In this study, we identified the origin and formation mechanism of haze using accelerated contamination experiments, also developed control methods for haze. From these results we expect that the photocontamination control technology should be developed and been a important part of NGL technology.