| 摘要 |
An object of the present invention is to provide a method for managing a light exposure mask wherein: a mask inspection or a wafer inspection, in order to manage a contamination of a light exposure mask by a growing foreign matter, is not necessary; the method has general versatility regardless to the history of the mask; the method dose not increase time and cost for mask manufacturing and inspection; and the method is operated so that the mask can always be used in a clean state. Another object of the present invention is to provide a light exposure mask wherein a contamination by a growing foreign matter dose not occur. A method for managing a light exposure mask is characterized in that: calculating a sulfate ion adsorption amount on a surface of the light exposure mask, of after a elapse of a predetermined time, from a sulfate ion concentration actually measured in an environment of using the light exposure mask, a maximum amount of sulfate ions adsorbed on the surface of the light exposure mask, and a threshold value of an amount of sulfate ions present on the surface of the light exposure mask of which the foreign matter occurs on the surface of the light exposure mask; setting an usable period of the light exposure mask, which the foreign matter dose not occur; and using the light exposure mask while rewashing the light exposure mask before the usable period expires. |
