Magnetic sensor having hard bias structure for optimized hard bias field and hard bias coercivity
AssigneeHGST Netherlands B.V.
InventorsQuang Le, David J. Seagle, Guangli Liu, Yongchul Ahn, Simon H. Liao
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Abstract
A magnetic read sensor having a hard bias structure that extends beyond the back edge of the sensor stack by a controlled, distance that is chosen to maximize both hard bias field and hard bias magnetic coercivity and anisotropy. The hard bias structure has a back edge that is well defined and that has a square corner at its innermost end adjacent to the sensor stack. The magnetic sensor can be constructed by a process that includes a separate making an milling process that is dedicated to defining the back edge of the hard bias structure.
Claims10
A magnetic read sensor, comprising:
- a sensor stack having a front edge disposed at an air bearing surface and a back edge opposite the air bearing surface, the distance between the front edge and the back edge defining a sensor stack stripe height;
- and
- a hard bias structure formed adjacent to the sensor stack and having a back edge opposite the air bearing surface, the distance between the air bearing surface and the back edge of the hard bias structure defining a hard bias length, the hard bias length being greater than the sensor stripe height;
- and
- a bi-layer insulation structure formed behind the back edge of the sensor stack, the bi-layer insulation structure including a layer of material that is resistant to ion milling and a layer of material that has an ion milling rate that is about the same as an ion milling rate of the sensor stack.
Dependencies are inferred from the claim text.