Soft X-ray emissions by Z-pinch discharge between vacuum spark electrodes were examined. Mainly aluminum and molybdenum were utilized to generate soft X rays, and emissions resulted for pulse currents of about 150 kA. These emissions increased as the discharge current increased. A large X-ray intensity was obtained when using a spherical anode and a conical cathode. A stable spot plasma was produced for an electrode separation distance of 2 mm. For molybdenum, the X-ray emission of the 0.52-nm line and continuous X rays of 0.65-1.2 nm were observed. The X-ray continuum was believed to be due to recombination. For aluminum ally containing magnesium, the 0.62-, 0.66-, 0.72-, 0.78-, and 0.92-nm lines were observed. These experimental results indicate that vacuum spark is a potential exposure source for X-ray lithography.
Hiroshi Arita (Hitachi Research Laboratory, Hitachi Ltd.)
Kouji Suzuki (Hitachi Research Laboratory, Hitachi Ltd.)
Yukio Kurosawa (Hitachi Research Laboratory, Hitachi Ltd.)
Kunio Hirasawa (Hitachi Research Laboratory, Hitachi Ltd.)