| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exposure mask which eliminate the necessity to inspect the mask and wafers for controlling contamination of the mask with haze, has versatility regardless of history of the mask, does not increase in time and cost to produce and inspect the mask, and prevents contamination with haze based on a management method for an exposure mask for using the mask in a clean condition at all times. <P>SOLUTION: In an environment in which an exposure mask is used, the amount of sulfate ion absorption on a surface of the exposure mask after elapse of a certain time period is calculated from the sulfate ion density measured in the environment, the maximum sulfate ion adsorbed on the exposure mask surface, and a threshold of the amount of sulfate ion existing on the exposure mask surface where an alien substance is generated. An expiration date until which the alien substance is not generated is established for the exposure mask. <P>COPYRIGHT: (C)2012,JPO&INPIT |
