Patent ID: 8158311
Filing Date: 2012-04-17
Classification: G03F

Abstract:
1. A method for managing a light exposure mask, wherein the light exposure mask contaminated by a sulfate ion-based foreign matter is rewashed and used by: calculating a sulfate ion adsorption amount on a surface of the light exposure mask, after a elapse of a predetermined time, from setting an usable period of the light exposure mask, which the foreign matter does not occur; and using the light exposure mask while rewashing the light exposure mask before the usable period expires, and wherein the light exposure mask is a mask for use in a light exposure apparatus including an ArF excimer laser as an exposure light source, and the 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, is 0.9 ng/cm