PURPOSE: To simplify the process for production by using a single-layer film consisting of a specific alloy for a bubble system information recording film.
CONSTITUTION: A valve 2 is set at a rotary pump 15 side and the pressure in a chamber (C) 1 is reduced down to 0.2Torr. The valve is then set to a cryostatic plump 4 side and after the inside of the chamber is evacuated to ≤1×10-5Torr, Ar is introduced form a gas line 5 into the C 1 at 20SCCM flow rate. The pressure in the C 1 is set at 5×10-3Torr by adjusting a conductance valve 3. After confirmation is made that this pressure does not change for about one minute, 100W DC electric power is impressed to a PbTe alloy target 7 from a power supply 6. The surface of the target 7 is subjected to sputter clearing for about one minute while a shutter 8 is held closed; thereafter, a PbTe film 11 is formed to 250 on a polycarbonate substrate set on a rotary jig 9, the atm. pressure is maintained in the C 1 by a gaseous N2 line 20 and the information recording medium 13 is formed. The monitoring of only the PbTe film thickness is thereby necessitated and, therefore, the recording medium is extremely easily produced.
MATSUBARA MOTONARI
OZAWA NORIO
