| 摘要 |
<p><P>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 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. <P>SOLUTION: The synthetic quartz glass material has a saturation point in 215 nm absorption curve when exposed to 5×10<SP>6</SP>pulses of ArF excimer laser with an energy density per pulse of 20 mJ/cm<SP>2</SP>and an oscillation frequency of 200 Hz in complete absence of hydrogen. Here, the saturation pointα<SB>S</SB>of absorbancy indexα<SB>215</SB>at a wavelength of 215 nm is within the range of 0.02-0.06, and the hydrogen molecule concentration C<SB>H2</SB>(molecule/cm<SP>3</SP>) of the material is within a predetermined range. <P>COPYRIGHT: (C)2004,JPO</p> |
