Magneto-optical recording medium and manufacturing method thereof
In a manufacturing method of a magneto-optical recording medium formed by laminating a plurality of magnetic layers, there is provided a manufacturing method whereby at least two of the magnetic layers can be properly and individually formed by sputtering the same target means in the same vacuum vessel under different conditions at the time of a sputtering process in accordance with an element composition ratio and/or magnetic characteristics of each layer.
1. A manufacturing method for a magneto-optical recording medium comprising a displacement layer, a control layer, a switching layer, and a memory layer, laminated over a substrate by sputtering, comprising the steps of:
forming at least said control layer and said switching layer by sputtering a same target in a same vacuum vessel; and
altering one or more processing conditions for a sputtering process that provides a different element composition ratio and magnetic characteristics for each of said control layer and switching layer, and
wherein said processing conditions include one or more of: a gas flow rate, a numerical aperture of an exhaust port, a gas type, a bias voltage to said substrate, and a distance between said substrate and said target, and
wherein said same target comprises a plurality of targets and said plurality of targets consist of different component elements, and
wherein said plurality of targets are alternately and periodically sputtered.
2. The manufacturing method for a magneto-optical recording medium as set forth in claim 1 , wherein said plurality of targets are alternately and periodically sputtered such that at no point are more than two of said targets being sputtered.
3. The manufacturing method for a magneto-optical recording medium as set forth in claim 1 , wherein said plurality of targets are alternately and periodically sputtered such that at no point are more than one of said targets being sputtered.
4. The manufacturing method for a magneto-optical recording medium as set forth in claim 3 , wherein said plurality of targets are alternately and periodically sputtered a plurality of times in order to form thin layers of each target such that the resultant plurality of thin layers is functionally equivalent to a single magnetic layer in which all of the plurality of targets are simultaneously sputtered.
5. The manufacturing method for a magneto-optical recording medium as set forth in claim 1 , wherein said plurality of targets are alternately and periodically sputtered a plurality of times in order to form thin layers of each target such that the resultant plurality of thin layers is functionally equivalent to a single magnetic layer in which all of the plurality of targets are simultaneously sputtered. target is also sputtered.
6. The manufacturing method for a magneto-optical recording medium as set forth in claim 1 , where said same plurality of targets include separate Al, Tb, Fe, and FeCo alloy targets.
7. A manufacturing method for a magneto-optical recording medium comprising a displacement layer, a control layer, a switching layer, and a memory layer, laminated over a substrate by sputtering, comprising the steps of:
forming at least said control layer and said switching layer by sputtering a same target in a same vacuum vessel; and
altering one or more processing conditions for a sputtering process that provides a different element composition ratio and magnetic characteristics for each of said control layer and switching layer, and
wherein said processing conditions include at least a rotational speed of a pallet onto which the substrate is attached.
8. The manufacturing method for a magneto-optical recording medium as set forth in claim 7 , where said same target is a system of separate Al, Tb, Fe, and FeCo alloy targets.
9. The manufacturing method for a magneto-optical recording medium as set forth in claim 7 , where said same target is a single TbFeCoAl alloy target.
10. The manufacturing method for a magneto-optical recording medium as set forth in claim 7 , where said same target is a system of separate Tb, Fe, and FeCo alloy targets, and wherein during the formation of said switching layer, an additional Al target is also sputtered.
11. A manufacturing method for a magneto-optical recording medium comprising a displacement layer, a control layer, a switching layer, and a memory layer, laminated over a substrate by sputtering, comprising the steps of:
forming at least said control layer and said switching layer by sputtering a same target in a same vacuum vessel; and
altering one or more processing conditions for a sputtering process that provides a different element composition ratio and magnetic characteristics for each of said control layer and switching layer, and
wherein said processing conditions include one or more of: a numerical aperture of an exhaust port, a bias voltage applied to said substrate, a gas flow rate, a gas type, a bias voltage to said substrate, a rotational speed of a pallet onto which the substrate is attached, and a distance between said substrate and said target.
12. The manufacturing method for a magneto-optical recording medium as set forth in claim 11 , where said same target is a system of separate Al, Tb, Fe, and FeCo alloy targets.
13. The manufacturing method for a magneto-optical recording medium as set forth in claim 11 , where said same target is a single TbFeCoAl alloy target.
14. The manufacturing method for a magneto-optical recording medium as set forth in claim 11 , where said same target is a system of separate Tb, Fe, and FeCo alloy targets, and wherein during the formation of said switching layer, an additional Al target is also sputtered.
15. The manufacturing method for a magneto-optical recording medium as set forth in claim 11 , where said same plurality of targets include separate Tb, Fe, and FeCo alloy targets, and wherein during the formation of said switching layer, an additional Al target is also sputtered.