Seeded underlayer in magnetic thin films
AssigneeSeagate Technology LLC
InventorBing Zhang
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Abstract
A seed layer is deposited under an underlayer in magnetic thin film media. The seed layer material has a similar lattice parameter and a similar crystal structure to the underlayer material. The preferred structure involves a nickel-aluminum seed layer, under a chromium underlayer, under a cobalt-based magnetic layer. Use of the nickel-aluminum seed layer produces higher coercivity and lower media noise in the resultant magnetic thin film. The coercivity and media noise values for the resultant magnetic thin film are dependent upon deposition parameters, and recommended deposition parameters are given.
Claims22
A thin film medium for magnetic recording of information, the thin film medium comprising:
- a substrate;
- a seed layer of nickel-aluminum alloy deposited over the substrate, the seed layer having a seed layer thickness;
- an underlayer of chromium-based metal deposited over the seed layer, the underlayer having an underlayer thickness which is about as thick or thicker than the seed layer thickness;
- and
- a film of a magnetic material deposited over the underlayer.
A method of manufacturing a thin film medium for magnetic recording of information, comprising the acts of:
- depositing a seed layer of nickel-aluminum alloy over a substrate to a seed layer thickness;
- depositing an underlayer of chromium-based metal over the seed layer to an underlayer thickness, the underlayer thickness being about as thick or thicker than the seed layer thickness;
- and
- depositing a magnetic thin film of cobalt-based alloy over the underlayer.
Dependencies are inferred from the claim text.