UV Light Exposure To Reduce Haze Growth Speed

The reticle haze in Photo process and the method of controlling were discussed. For this reticle haze defect, the main problem was analyzed in detail and got the solution finally. This defect solution has been implement successfully. The follow will list the three problems.1. The reticle haze problem in Photo processReticle haze defect is a serious issue for PH process, haze will impact reticle transmit rate and may cause PH repeating defect.2. The root cause of reticle haze and its bad impactThe root cause is ammonia react with acid then generate compound, and usually haze will generate after run lots more than 5 month. Then we need remount and clean this reticle, it is not only large cost but also impact MFG turn ratio and wafer out.3. The control method of reticle hazeUse short wavelength irradiation before clean to excitated ammonia fully react with acid. So ammonia and acid residue on reticle will be largely reduced. And reticle can be used more than 1 year without haze defect.