PRODUCTION OF PHOTOMAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To provide a process for producing a photomagnetic recording medium with which written micro-bits are stably held and which is improved in recording density with a magnetron sputtering method by specifying the compsn. of targets and the bias voltage to be impressed to a base plate. CONSTITUTION:The 1st target 2 consisting of Cd, Tb, the 2nd target 3 consisting of Fe, Co, a discoid base plate 4 which is driven to rotate and on which a thin Gd-Tb-Fe-Co alloy film is formed and a freely rotatable discoid shield plate 5 are disposed in a vacuum vessel 1. A pair of discoid through-holes 6 are formed respectively right above the 1st and 2nd targets to the plate 5. The various metals scattering from the 1st and 2nd targets pass through the holes 6 and are deposited by evaporation of the rotating plate 4 during film formation. High-frequency electric power of 100W-5kW is impressed between the 1st target and 2nd target as well as the plate 4 during the film formation. A bias voltage of +50--40V is impressed from a DC power source 9 to the plate 4 and both voltages are respectively set within a prescribed range.