Magnetoresistive sensor element with synthetic antiferromagnet biasing
AssigneeNVE Corporation
InventorsJoe Davies, Justin Watts
Life of this patent
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Abstract
Apparatus and associated methods relate to a magnetoresistive sensor element with synthetic antiferromagnetic biasing structure separated, by a non-magnetic tuning spacer, from a free ferromagnetic layer of a TMR/GMR sensor. The synthetic antiferromagnetic biasing structure includes first and second ferromagnetic layers separated from one another by a synthetic antiferromagnetic spacer. The synthetic antiferromagnetic biasing structure is biased during manufacture and pinned via exchange coupling with an adjacent antiferromagnetic layer. The synthetic antiferromagnetic biasing structure biases the free ferromagnetic layer via tuned exchanged coupling via relative proximity controlled by thickness of the non-magnetic tuning spacer.
Claims20
A magnetoresistive sensor element with synthetic antiferromagnet biasing, the magnetoresistive sensor element comprising:
- a GMR/TMR sensor including:
- a sensing ferromagnetic layer formed on an opposite side of a spacer layer from a reference structure;
- a synthetic antiferromagnetic biasing structure including:
- a sense pinned ferromagnetic layer formed on an opposite side of a sense non-magnetic spacer from a sense biasing ferromagnetic layer;
- and
- an exchange-tuning spacer sandwiched between the sensing ferromagnetic layer and the sense biasing ferromagnetic layer.
A method of manufacturing a synthetic antiferromagnet biased magnetoresistive sensor, the method comprising:
- depositing a reference structure;
- depositing a spacer upon the reference structure;
- depositing a sensing ferromagnetic layer on the spacer;
- depositing an exchange-tuning spacer on the sensing ferromagnetic layer;
- depositing a synthetic antiferromagnetic biasing structure on the exchange-tuning spacer;
- and
- depositing a capping layer on the synthetic antiferromagnetic biasing structure.
Dependencies are inferred from the claim text.