Western Digital (fremont), Inc.

Western Digital Technologies, Inc.

Anup Roy

Ming Mao

Daniele Mauri

Guanxiong Li

Zhihong Zhang

Yuankai Zheng

Shaoping Li

Mahendra Pakala

Gerardo Bertero

Chih-Ching Hu

Chen-jung Chien

Michael L Mallary

Rongfu Xiao

Qunwen Leng

Zhitao Diao

Yunfei Ding

Wei Gao

Yung-Hung Wang

Laurence Lujun Chen

Ling Wang

Amritpal Singh Rana

Miao Wang

Chen Jung Chien

Ming Jiang

Wei Zhang

Kuok San Ho

Yi Zheng

Xiaoyong Liu

Hai Sun

Savas Gider

Guanghong Luo

Xiaozhong Dang

Lingyun Miao

Yukimasa Okada

Shihai He

Xiaoyu Yang

Changhe Shang

Goncalo Marcos Baião De Albuquerque

Wencheng Su

Hongxue Liu

James Yuan

Goncalo Albuquerque

The present disclosure generally relates to a dual free layer (DFL) two dimensional magnetic recording (TDMR) read head. The read head comprises a first sensor, a first rear hard bias (RHB) structure disposed adjacent to the first sensor, an upper shield disposed over the first sensor and first RHB structure, a lower shield disposed over the upper shield, a second sensor disposed over the lower shield, and a second RHB structure disposed adjacent to the second sensor. A first surface of the first sensor is substantially flush or aligned with a first surface of the first RHB structure. A first surface of the second sensor is substantially flush or aligned with a first surface of the second RHB structure. The upper shield extends linearly from a media facing surface into the read head. The first lower shield is over-milled a greater amount of time than the second lower shield.

Planar design for sensors in a dual free layer read head

The present disclosure generally related to a two dimensional magnetic recording (TDMR) read head having a magnetic tunnel junction (MTJ). Both the upper reader and the lower reader have a dual free layer (DFL) MTJ structure between two shields. A synthetic antiferromagnetic (SAF) soft bias structure bounds the MTJ, and a rear hard bias (RHB) structure is disposed behind the MTJ. The DFL MTJ decreases the distance between the upper and lower reader and hence, improves the area density capacity (ADC). Additionally, the SAF soft bias structures and the rear head bias structure cause the dual free layer MTJ to have a scissor state magnetic moment at the media facing surface (MFS).

Two-dimensional magnetic recording reader with dual free layer magnetic tunnel junction

A magnetic read apparatus includes a media-facing surface (MFS), a sensor, a shield structure, a side bias structure, and a shield reference bias structure. The sensor includes a free layer and a nonmagnetic layer. The shield structure includes a shield pinning structure and a shield reference structure between the shield pinning structure and the nonmagnetic layer. The nonmagnetic layer is between the free layer and a shield reference structure. The shield pinning structure includes a pinned moment oriented in a first direction. The shield reference structure includes a reference structure moment weakly coupled with the pinned moment. The side bias structure is adjacent to a side of the free layer and biases the free layer in a first direction parallel to the MFS. The shield reference bias structure is adjacent to the shield reference structure and biases the shield reference structure in a direction opposite to the first direction.

Free layer only magnetic reader that may have a reduced shield-to-shield spacing and a multilayer side bias

A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.

Magnetic read head with antiferromagentic layer

A method provides a magnetic read apparatus. A sensor stack is deposited. The read sensor is defined from the stack such that the sensor has sides forming a junction angle of 75 degrees-105 degrees from a sensor bottom. Defining the sensor includes performing a first ion mill at a first angle and a first energy and performing a second ion mill at a second angle greater than the first angle and at a second energy less than the first energy. The first angle is 5 degrees-30 degrees from normal to the top surface. After the first ion mill, less than half of the stack's bottom layer depth remains unmilled. Magnetic bias structure(s) adjacent to the sides may be formed. The magnetic bias structure(s) include a side shielding material having at least one of the saturation magnetization greater than 800 emu/cmand an exchange length less than five nanometers.

Method and system for fabricating high junction angle read sensors

Disclosed are methods for making ultra-narrow track width (TW) read sensors, and read transducers incorporating such sensors. The methods utilize side-wall line patterning techniques to prepare ultra-narrow mill masks that can be used to prepare the ultra-narrow read sensors.

Method for making ultra-narrow read sensor and read transducer device resulting therefrom

Systems and methods for controlling a thickness of a soft bias layer in a tunnel magnetoresistance (TMR) reader are provided. One such method involves providing a magnetoresistive sensor stack including a free layer and a bottom shield layer, performing contiguous junction milling on the sensor stack, depositing an insulating layer on the sensor stack, depositing a spacer layer on the insulating layer, performing an angled milling sub-process to remove preselected portions of the spacer layer, depositing a soft bias layer on the sensor stack, and depositing a top shield layer on the sensor stack and the soft bias layer. The method can further involve adjusting an alignment of a top surface of the spacer layer with respect to the free layer. In one such case, the top surface of the spacer layer is adjusted to be below the free layer.

Systems and methods for controlling soft bias thickness for tunnel magnetoresistance readers

Method of manufacturing a magnetic read head

A method and system for providing a magnetic transducer is described. The method and system include providing an underlayer, a seed structure, and a magnetically hard layer. The underlayer has a surface. The seed structure resides on the surface and includes an amorphous layer and a seed layer. The amorphous layer wets the surface of the underlayer. The seed layer having a natural growth texture. The magnetically hard layer resides on the seed structure. The seed layer resides between the magnetically hard layer and the amorphous layer. The magnetically hard layer has a desired crystal orientation corresponding to the natural growth texture of the seed layer.

Method and system for providing a magnetic transducer having an improved hard bias seed layer

A method and system provide a magnetic transducer having an air-bearing surface (ABS). The magnetic transducer includes a first shield, a read sensor, at least one soft magnetic bias structure and at least one hard bias structure. The read sensor includes a sensor layer that has at least one edge in the track width direction along the ABS. The soft magnetic bias structure(s) are adjacent to the edge(s) of the sensor layer. The soft magnetic bias structure has a first permeability. The soft bias structure(s) are between the read sensor and the hard bias structure(s). The hard bias structure(s) are adjacent to a portion of the soft bias structure(s) and have a second permeability. The first permeability is at least ten multiplied by the second permeability.

Method and system for providing a read transducer having soft and hard magnetic bias structures

A magnetic read transducer is described with a magnetoresistive sensor that has a free layer, and an antiferromagnetically-coupled (AFC) soft bias layer for magnetically biasing the free layer. The free layer has a first edge in a track width direction along an air-bearing surface (ABS). At least a portion of the AFC soft bias layer is conformal to at least a portion of a second edge of the free layer, and situated to form a magnetic moment at an angle with respect to a center line of the free layer. The center line of the free layer extends in the same direction as the free layer first edge that is in the track width direction along the ABS.

Antiferromagnetically-coupled soft bias magnetoresistive read head, and fabrication method therefore

A read sensor for a transducer is fabricated. The transducer has a field region and a sensor region corresponding to the sensor. A sensor stack is deposited. A hybrid mask including hard and field masks is provided. The hard mask includes a sensor portion covering the sensor region and a field portion covering the field region. The field mask covers the field portion of the hard mask. The field mask exposes the sensor portion of the hard mask and part of the sensor stack between the sensor and field regions. The sensor is defined from the sensor stack in a track width direction. Hard bias layer(s) are deposited. Part of the hard bias layer(s) resides on the field mask. Part of the hard bias layer(s) adjoining the sensor region is sealed. The field mask is lifted off. The transducer is planarized.

Method for fabricating a read sensor for a read transducer

A method for providing a hard bias structure is provided. The method comprises providing a seed layer for a hard bias layer, the seed layer having a seed layer lattice constant and a natural growth texture. The method further comprises depositing the hard bias layer for the hard bias structure on the seed layer, the natural growth texture corresponding to a texture for the hard bias layer. The hard bias layer has a bulk lattice constant. The step of providing the seed layer includes forming a first plasma of a first deposition gas configured to expand the seed layer lattice constant if the bulk lattice constant is greater than the seed layer constant. The step of depositing the hard bias layer includes forming a second plasma of a second deposition gas configured to expand the bulk lattice constant if the seed layer lattice constant is greater than the bulk lattice constant.

Method for providing an improved hard bias structure

A method and system for fabricating a magnetic transducer is described. A magnetic junction is defined from the magnetoresistive stack. The magnetic junction has a top and a plurality of sides. The step of defining the magnetic junction redeposits a portion of the magnetoresistive stack and forms fencing adjacent to the top of the magnetic junction. At least one hard bias structure is provided after the magnetic junction is defined. A first portion of the at least one hard bias structure is substantially adjacent to the magnetoresistive junction in a track-width direction. The magnetic junction is ion beam planarized, thereby substantially removing the fencing.

Method and system for defining a read sensor using an ion mill planarization

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Fremont, CA, United States of America

Anup Roy