| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce film thickness unevenness that occurs in association with the provision of a stress buffer layer to suppress film stress that causes the deformation of a substrate. <P>SOLUTION: An optical element for X-ray includes the substrate, a first multilayer film having a reflection property with respect to light in a soft X-ray wavelength range, and a second multilayer film, disposed between the substrate and the first multilayer film, for reducing film stress of the first multilayer film. The second multilayer film includes a periodic structure having a unit period film thickness which is 90% or more and less than 110% of a two or more integral multiple of 7 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT |
