Western Digital (Fremont), Inc.

Western Digital Technologies, Inc.

Guanxiong Li

Ming Mao

Chen-jung Chien

Zhihong Zhang

Daniele Mauri

Chih-Ching Hu

Anup Roy

Wei Zhang

Mahendra Pakala

Rongfu Xiao

Wei Gao

Ming Jiang

Xiaoyong Liu

Yong Shen

Hai Sun

Xiaozhong Dang

Yukimasa Okada

Yung-Hung Wang

Miao Wang

Hongxue Liu

Shaoping Li

Michael L Mallary

Yi Zheng

Gerardo Bertero

Jinqiu Zhang

Ying Hong

Ge Yi

Yufeng Hu

Savas Gider

Guanghong Luo

Tsung Yuan Chen

Hongping Yuan

Hongquan Jiang

Zhongyan Wang

Lingyun Miao

Xiaoyu Yang

Wencheng Su

Xiaohai Xiang

Rong Cao

Goncalo Albuquerque

James Yuan

The present disclosure generally relates to a dual free layer (DFL) two dimensional magnetic recording (TDMR) read head, and a method of forming thereof. The read head comprises a lower sensor, middle shields disposed on the lower sensor, and an upper sensor disposed on the middle shields. After the lower reader is formed, a dielectric layer is deposited around an outer perimeter of the lower shield. Portions of the dielectric layer are ion milled such that the remaining portions form a substantially flat layer. Another embodiment includes a deposition of a TaOx layer on the dielectric layer, where x is a numeral. Portions of the dielectric layer and the TaOx layer are then ion milled such that the remaining portions of the TaOx layer and the dielectric layer collectively form a substantially planar layer. The middle shields are formed over the lower reader and are substantially planar.

Two-dimensional magnetic recording read head with TaOx layer for flat middle shield topography and method of forming thereof

The present disclosure generally relate to a read head and methods of forming thereof. Upon forming a dual free layer (DFL) sensor and a rear hard bias (RHB) structure on a seed layer, a photoresist is deposited on the DFL read head and the RHB structure. A refill layer is deposited on the photoresist and the seed layer adjacent to the DFL sensor and the RHB structure. Portions of the refill layer disposed on one or more sidewalls of the photoresist are removed, and a SiOx cap layer is deposited on the refill layer and on the one or more sidewalls. The photoresist is removed, and the SiOx cap layer and top surfaces of the DFL sensor and the RHB structure are planarized to form a substantially flat topography. The SiOx cap layer acts as a stop layer for the refill layer, and remains in the finished read head.

DFL read head with SiOx cap layer on AlOx refill layers

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

The present disclosure generally related to read heads having dual free layer (DFL) sensors. The read head has a sensor disposed between two shields. The sensor is a DFL sensor and has a surface at the media facing surface (MFS). Behind the DFL sensor, and away from the MFS, is a rear hard bias (RHB) structure. The RHB structure is disposed between the shields as well. In between the DFL sensor and the RHB structure is insulating material. The RHB is disposed on the insulating material. The RHB includes a RHB seed layer as well as a RHB bulk layer. The RHB seed layer has a thickness of between 26 Angstroms and 35 Angstroms. The RHB seed layer ensures the read head has a strong RHB magnetic field that can be uniformly applied.

Effective rear hard bias for dual free layer read heads

A hybrid read head structure for two-dimensional magnetic recording (TDMR) in a disk drive has two stacked current-perpendicular-to-the plane magnetoresistive (CPP-MR) read heads or sensors substantially aligned with one another in the along-the track direction to enable both sensors to read data from the same data track. The structure is a hybrid structure formed on the disk drive slider with the lower sensor being a dual free layer (DFL) or scissoring type of CPP-MR sensor and the upper sensor being a single free layer (SFL) type of CPP-MR sensor.

Two-dimensional magnetic recording (TDMR) read head structure with different stacked sensors and disk drive incorporating the structure

A method of forming a magnetic head includes forming a read sensor stripe, depositing an electronic lapping guide (ELG) layer over the substrate in an ELG region, forming a backside edge of a read sensor by patterning the read sensor stripe in a first patterning step, forming a backside insulator layer and a rear bias magnetic material portion over the backside edge of the read sensor, forming a backside edge of an ELG by patterning the ELG layer in the ELG region in a second patterning step, simultaneously forming a front side edge of the read sensor and a front side edge of the ELG, and lapping the read sensor and the ELG to provide an air bearing surface of a read sensor. The physical stripe height offset can be determined for each flash field by correlating device conductance and ELG conductance.

Method of forming a magnetic head

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

A magnetic recording transducer comprises a magnetoresistive sensor having a left side, a right side opposite to the left side, a left junction angle at the left side, a right junction angle at the right side, and a track width. The right junction angle and the left junction angle are characterized by a junction angle difference of not more than six degrees. The track width is less than one hundred nanometers. The magnetic recording transducer further comprises a left hard bias structure residing adjacent to the left side of the magnetoresistive sensor, and a right hard bias structure residing adjacent to the right side of the magnetoresistive sensor.

Magnetic recording transducer

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.

Tunnel magnetoresistance read head with narrow shield-to-shield spacing

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

A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method provides a first read sensor stack and defines a first read sensor in a stripe height direction from the first read sensor stack. The stripe height direction is perpendicular to the ABS. A shield is provided on the first read sensor stack and in a down track direction from the first read sensor stack. A second read sensor stack is provided. The shield is between the first read sensor and the second read sensor stack in the down track direction. Both the first read sensor and the second read sensor are defined from the first read sensor stack and from the second read sensor stack, respectively, in a cross-track direction. The cross-track direction is substantially perpendicular to the down track direction and substantially perpendicular to the stripe height direction.

Shield designed for middle shields in a multiple sensor array

A magnetic head including a magnetoresistive junction and an oxide layer. The magnetoresistive junction includes a pinned layer, a free layer, and a barrier layer residing between the pinned and free layer. The magnetoresistive junction includes at least one side having a smooth profile. The oxide layer is on the at least one side. The oxide layer is less than one nanometer thick at the free layer.

Magnetic head having a magnetoresistive junction and side oxide layers

A method and system provide a substantially seamless interface in a magnetic transducer. The magnetic recording transducer includes a first layer and a second layer on the first layer. The second layer is different from the first layer. The first layer consists of at least one material. The method includes removing at least the second layer using a first removal process. A residue of the second layer and a first portion of the first layer remain after the first removal process. A first sacrificial layer consists of the at least one material on the first portion of the first layer. At least the first sacrificial layer is removed using a second removal process. A second portion of the first layer remains after completion of the second removal process. An additional structure is provided. The seamless interface is between the second portion of the first layer and the additional structure.

Method and system for providing a read transducer having seamless interfaces

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Fremont, CA, United States of America

Guanxiong Li