PURPOSE: To obtain the photomagnetic recording medium excellent in reproducibility and never causes a device to deteriorate by using mixed gas of inert gas and hydrogen gas as sputter gas used for sputtering.
CONSTITUTION: A target which has a small piece of Tb arranged on a Co disk of 110mm in diameter so that its occupation area is 35% of that of the disk is used. A vacuum is produced up to a 8×10-7Torr attainable degree of vacuum and then the mixed sputter gas of hydrogen gas varied in addition amount and argon gas is admitted into a vacuum tank for sputtering; and high frequency electric power of 100W is applied under 5×10-3Torr total pressure to perform sputtering, thereby forming a Tb-Co thin film on a glass substrate. Even if there is time or spatial variation in hydrogen partial pressure PH2, the value Ku does not vary greatly and the reproducibility of the Ku value is high. The Ku value is controllable according to the composition of the target for sputtering, i.e. the number of Tb small pieces arranged on the Co plate.
KANEKO KATSUHIRO
TAKAYAMA SHINJI
SUGITA KEN
