| 摘要 |
<p>PURPOSE: To obtain high X-ray absorbing material with a small thermal expansion coefficient and high dry-etching performance by a method wherein the absorber pattern, to be formed on a mask membrane, is formed by alloy containing tungsten and molybdenum. CONSTITUTION: A silicon substrate, which becomes an X-ray retaining frame 1, is connected to the frame 4, which is a reinforcement member, formed by heat-proof glass and the like. A SiN membrane film, which becomes an X-ray retaining film 2, is formed on the above-mentioned silicon substrate using a CVD method, and mask blanks are formed. On the X-ray retaining film 2, an X-ray absorber pattern, formed by alloy containing tungsten and molybdenum, is formed by dry-etching the Si substrate using the gas plasma mainly composed of sulphur carbon or sulphur fluoride gas. As a result, a high density X-ray absorber, having uniform composition and excellent surface properties, can be formed with a small stress.</p> |
