SYNTHETIC QUARTZ GLASS MATERIAL FOR OPTICAL MEMBER

摘要

PROBLEM TO BE SOLVED: To provide a synthetic quartz glass material having optical characteristics optimum for composing an optical system of exposure equipment employing an ArF excimer laser as a light source and solves the problems of decrease in long-term transmission and transmission at an initial stage of laser irradiation, essential to the synthetic quartz glass material for an ArF excimer laser optical member, and rarefaction caused by low-energy density irradiation.

SOLUTION: The synthetic quartz glass material for the ArF excimer laser optical member is used in an energy density region wherein the energy density per pulse is≤0.03 mJ/cm2. The decrease in transmission of ArF excimer laser beam is adjusted to 1-2% per 1 cm optical axis when exposed to 1×104pulses of ArF excimer laser with an energy density per pulse of 20 mJ/cm2and an oscillation frequency of 200 Hz, and the decrease in transmission of ArF excimer laser beam is adjusted to 0.5-1% per 1 cm optical axis when exposed to 2×106pulses of ArF excimer laser under the same irradiation condition.

COPYRIGHT: (C)2004,JPO