| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a substrate which has an excellent flatness suitable for an EUV (Extreme UltraViolet) mask or an EUV mask blanks. <P>SOLUTION: A substrate 11 for an EUV mask is made of a material of silica glass containing 1-12 wt.% of TiO<SB>2</SB>, and has a surface roughness (rms) of 2 nm or below in a surface quality region. The substrate has a maximum stress variation (PV) of 0.2 MPa or below in a the surface quality region and has a thermal expansion coefficient of 200 ppb/°C in a temperature range of 0-100°C. <P>COPYRIGHT: (C)2010,JPO&INPIT |
