| 摘要 |
<p>PURPOSE:To obtain a membrane whose tensile stress is stable even after irradiation with X-rays by a method wherein, after a compound for the membrane is formed in a compressive stress state on a substrate, it is heat-treated to be transformed into a tensile stress state. CONSTITUTION:An amorphous BNC:H film 2 for membrane use is formed to be a thickness of 6 mum on a silicon substrate 1. A pressure inside a chamber during the formation is 60-200 Pa; high-frequency electric power at 13.56 MHz is impressed on an upper-part electrode in order to obtain an electric-power density of 0.1-0.3 W/cm<2>. By this setup, the BNC:H film 2 in a weak compressive stress state of -1.0X10<9>dyn/cm<2>--1.0X10<8>dyn/cm<2> is formed. Then, a specimen is taken out from a chamber, and is heat-treated at a temperature of 700-1000 deg.C for 30-60 min in a mixed atmosphere of nitrogen and hydrogen. By this process, the BNC:H film 2 is transformed into a film in the compressive stress state of 1X10<8>-2X10<9> dyn/cm<2>. After the central part on the rear surface of the silicon substrate is removed by etching, a mask pattern 3 composed of an X-ray absorber such as gold, tantalum or the like is patterned and formed on the membrane. The membrane of an X-ray mask obtained in this manner does not cause the segregation of boron and a fluctuation in a stress even when it is irradiated with X rays.</p> |
