Tunneling magneto-resistive spin valve sensor with novel composite free layer
AssigneeHeadway Technologies, Inc.
InventorsTong Zhao, Hui-Chuan Wang, Chyu-Jiuh Torng
Life of this patent
Estimating the term…
Abstract
The conventional free layer in a TMR read head has been replaced by a composite of two or more magnetic layers, one of which is iron rich The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.
Claims12
A free layer for use with a magnetic tunnel junction (MTJ), comprising:
- a first free layer (FL1) comprising one or more elements selected from the group consisting of Co, Fe, and Ni;
- and
- on said FL1 layer a single second free layer (FL2) of FexNi1-x, uniform in composition over both its area and its depth, where x is greater than 0.65 and less than or equal to 0.7999, said FL1 and FL2 layers together forming said free layer.
A free layer for use with a magnetic tunnel junction (MTJ), comprising:
- a first free layer (FL1) comprising two or more elements selected from the group consisting of Co, Fe, and Ni;
- and
- on said FL1 layer at least two magnetic layers, one of which contains at least 50 atomic percent of iron and is between about 2 and 80 Angstroms thick, said FL1 and said two or more magnetic layers together constituting said free layer.
A Tunneling Magnetoresistive (TMR) read head, having a free layer, comprising:
- on a lower lead layer, a seed layer and a pinning layer;
- on said pinning layer, a pinned layer;
- a non magnetic tunneling layer on said pinned layer;
- on said non magnetic tunneling layer, a first free layer (FL1) comprising two or more elements selected from the group consisting of Co, Fe, and Ni;
- on said FL1 layer, a second free layer (FL2) of FexNi1-x, where x is between 0.6 and 0.8, said FL1 and FL2 layers together constituting said free layer;
- and
- on said free layer, a capping layer and an upper lead layer.
A Tunneling Magnetoresistive (TMR) read head, having a free layer, comprising:
- on a lower lead layer, a seed layer and a pinning layer;
- on said pinning layer, a pinned layer;
- a non magnetic tunneling layer on said pinned layer;
- on said non magnetic tunneling layer a first free layer (FL1) comprising two or more elements selected from the group consisting of Co, Fe, and Ni;
- on said FL1 layer a second free layer (FL2) containing at least 50 atomic percent of iron, said FL1 and FL2 layers together constituting said free layer;
- and
- on said free layer, a capping layer and an upper lead layer.
Dependencies are inferred from the claim text.