Headway Technologies, Incorporated

Kabushiki Kaisha Toshiba

Tdk Corporation

Applied Spintronics, Inc.

Magic Technologies, Inc.

Synopsys, Inc.

Min Li

Kunliang Zhang

Cheng Tzong Horng

Kochan Ju

Hui-Chuan Wang

Simon H Liao

Tong Zhao

Ru-Ying Tong

Yu-Hsia Chen

Yuchen Zhou

Yewhee Chye

Mao-Min Chen

Cherng-Chyi Han

Chyu-Jiuh Torng

Glen A Garfunkel

Yue Liu

Cherng Chyi Han

Min Zheng

Junjie Quan

Yan Wu

Ruhang Ding

Moris Musa Dovek

Wenyu Chen

Chen-Jung Chien

Lijie Guan

Fenglin Liu

Jianing Zhou

Hideaki Fukuzawa

Hiromi Yuasa

Jiun-Ting Lee

Jeiwei Chang

Charles C Lin

Masashi Sano

Yuhui Tang

Tai Min

Bernard Dieny

Joe Smyth

Youfeng Zheng

Yu-Chen Zhou

Yoshihiko Fuji

Michiko Hara

Kenichi Takano

Yun-Fei Li

Shengyuan Wang

Kiyoshi Noguchi

Katsuhiko Koui

Liubo Hong

Ying Liu

Hui Wang

Pokang Wang

Shohei Kawasaki

You Feng Zheng

Minghui Yu

Ben Hu

You Fong Zheng

Yoshitaka Sasaki

Hiroyuki Ito

Shigeki Tanemura

Hironori Araki

Zhigang Bai

Erhard Theodor Schreck

Shuichi Murakami

Kenichiro Yamada

Soichi Oikawa

Tom Zhong

Kowang Liu

Yoshinari Kurosaki

Chyu Jiuh Torng

Chunping Luo

Stuart Kao

Chao Chen

Koichi Terunuma

Daniel Gerard Abels

Dan Abels

Otto Vogeli

Hitoshi Iwasaki

Masayuki Takagishi

Kazuki Sato

Yimin Guo

Satoshi Shirotori

Tetsuya Roppongi

Akihiko Takeo

Tomomi Funayama

Jei-Wei Chang

Rongfu Xiao

Xuhui Jin

Masahiro Takashita

Weihao Xu

Joseph Francis Smyth

Sung Soo Chung

Chao-Peng Chen

Ru Ying Tong

Xiaomin Liu

David Hu

Yoji Nomura

Tetsuhito Shinohara

Norihito Fujita

Qiuyang Wu

PoKang Wang

Rong-Fu Xiao

Systems and methods for controlling a critical dimension (CD) uniformity of a magnetic head device are described. A film stack that is part of a system for controlling a critical dimension (CD) uniformity of a magnetic head device can include a substrate, a magnetoresistive (MR) sensor layer, and a hard mask layer. The system can also include a first mask that defines critical shape patterns other than the CD. The hard mask layer can be patterned using the first mask. The system can also include a second mask that defines the CD. A mandrel pattern can be formed on the hard mask layer using the second mask.

System for controlling a critical dimension (CD) uniformity of a magnetic head device

A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or in another embodiment, the PM layer adjoins a backside of the top shield and has a width equal to or greater than that of the FL.

Adaptive bias control for magnetic recording head

Methods of critical dimension (CD) uniformity control for magnetic head devices are disclosed. In some embodiments, a method can include providing a film stack, the film stack including a substrate, a magnetoresistive (MR) sensor layer, and a hard mask layer, patterning the hard mask layer using a first mask that defines critical shape patterns other than the CD, forming a mandrel pattern using a second mask that defines the CD, and forming a sidewall spacer pattern on sidewalls of the mandrel pattern, and removing the mandrel pattern.

Method of ultra-fine critical dimension patterning for magnetic head devices

A read head includes a permanent magnet (PM) layer formed up to 100 nm behind a free layer where PM layer magnetization may be initialized in a direction that adjusts free layer (FL) bias point, and shifts sensor asymmetry (Asym) closer to 0% for individual heads at slider or Head Gimbal Assembly level to provide a significant improvement in device yield. Asym is adjusted using different initialization schemes and initialization directions. With individual heads, initialization direction is selected based on a prior measurement of asymmetry. The PM layer is CoPt or CoCrPt and has coercivity from 500 Oersted to 1000 Oersted. The PM layer may have a width equal to the FL, or a width equal to the cross-track distance between outer sides of the longitudinal bias layers. In another embodiment, the PM layer adjoins a backside of the top shield.

A magnetic head includes a medium facing surface, a main pole, a trailing shield, and a spin torque oscillator. A bottom surface of the trailing shield includes a first portion that includes an end located in the medium facing surface and is in contact with the spin torque oscillator at least in part. An element height that is a dimension of the spin torque oscillator in a direction perpendicular to the medium facing surface and a writer height that is a dimension of the first portion in the direction perpendicular to the medium facing surface are different from each other.

Magnetic head including spin torque oscillator

A hard magnet stabilization scheme is disclosed for a top shield and junction shields for double or triple dimension magnetic reader structures. In one design, the hard magnet (HM) adjoins a top or bottom surface of all or part of a shield domain such that the HM is recessed from the air bearing surface to satisfy reader-to-reader spacing requirements and stabilizes a closed loop magnetization in the top shield. The HM may have a height and width greater than that of the top shield. The top shield may have a ring shape with a HM formed above, below, or within the ring shape, and wherein the HM stabilizes a vortex magnetization. HM magnetization is set or reset from room temperature to 100&#xb0; C. to maintain a desired magnetization direction in the top shield, junction shield, and free layer in the sensor.

Hard magnetic stabilized shield for double (2DMR) or triple (3DMR) dimension magnetic reader structures

A method of forming a spin torque assisted magnetic recording writer is disclosed wherein a spin flipping (STO) device is recessed from an air bearing surface. The STO device has a middle flux guiding layer with a magnetization that flips to a direction anti-parallel to the write gap field when a current of sufficient magnitude is applied from the trailing shield towards the main pole (MP) thereby increasing reluctance in the write gap to enhance writability. A STO stack is deposited and patterned to define a cross-track width on the MP tapered trailing side. Thereafter, the STO stack is patterned to define a STO device with a front side recessed from the air bearing surface, and a backside. A write gap is deposited surrounding the STO device, and has a thickness greater than or &#x2264; to STO thickness to enable design flexibility. Then, first and second trailing shields are formed.

Process of forming a recessed spin flipping element in the write gap

The use of supermalloy-like materials such as NiFeMe where Me is one or more of Mo, Cr, and Cu for the side and top shields of a magnetic bit sensor is shown to provide better shielding protection from stray fields because of their extremely high permeability. Moreover, the side shield may comprise a stack in which a Ni, Fe, Co, FeNi, CoFe, or FeCo is sandwiched between two NiFeMe layers to enhance the bias field on an adjacent free layer. Including NiFeMe in a side shield results in an increase in readback amplitude under the same asymmetric sigma. For these sensors, the signal to noise ratio was higher and the bit error rate was lower than with conventional materials in the side shield. A method is disclosed for forming a magnetic bit sensor having supermalloy-like materials in the side shields.

Supermalloy and MU metal side and top shields for magnetic read heads

A PMR writer is disclosed wherein the trailing shield (TS) structure has a high moment trailing shield (HMTS) with a saturation (Bs) from 19 kiloGauss (kG) to 24 kG and a width (w) from 10 nm to 500 nm and is separated from the main pole (MP) trailing side at an air bearing surface (ABS) by a first write gap (WG) portion of thickness tA second WG portion of thickness twhere ttadjoins the sides of the first WG portion, and has an outer side at a cross-track distance &#xbd; wfrom a center plane that bisects the MP trailing side where ww. A first TS layer is formed on the HMTS and on the second WG portion, and has an outer side coplanar with the second WG portion outer side. Accordingly, there is improvement in tracks per inch capability and adjacent track interference.

Perpendicular magnetic recording (PMR) writer with narrow high moment trailing shield

Hard magnet stabilized shield for double (2DMR) or triple (3DMR) dimension magnetic reader structures

A PMR (perpendicular magnetic recording) head is configured for thermally assisted magnetic recording (TAMR). The thermal energy is supplied by the near-fields of plasmons and the near-fields are directed to a magnetic recording medium by a PPG layer. The PPG layer is Rhodium (Rh) whose small-grained crystal structure normally makes it subject to thermal deformations and other weaknesses. By growing the PPG layer on a thin template layer (TTL), the portion of the PPG layer adjacent to the air-bearing surface (ABS) develops a larger grain size and stronger forces between its atomic constituents which makes it resistant to those deformations.

Rhodium film with thin template layer and its application to a thermally assisted magnetic recording (TAMR) writer

A method and apparatus for on chip variation path-based pessimism reduction and improving analysis of a hierarchical integrated circuit design in an electrical circuit. The circuit has one or more block circuit levels and a top circuit level. The method in one embodiment comprises characterizing the top circuit level to produce a context function, the context function used by the block circuit level for evaluation.

Method to perform full accuracy hierarchical block level timing analysis with parameterized chip level contexts

A seed layer stack with a smooth top surface having a peak to peak film thickness variation of about 0.5 nm is formed by sputter depositing a second seed layer on a first seed layer that is Mg, MgN, or an alloy thereof where the second seed layer has a bond energy substantially greater than that of the first seed layer. The second seed layer may be Ta or NiCr. In some embodiments, an uppermost seed layer that is one or both of Ru and Cu is deposited on the second seed layer. Higher coercivity (Hc) and perpendicular magnetic anisotropy (Hk) is observed in an overlying ferromagnetic layer than when a prior art seed layer stack is employed. The first seed layer has a thickness from 2 to 20 Angstroms and has a resputtering rate about 2 to 40 times that of the second seed layer.

Composite seed layer

A process flow is disclosed for forming a MR sensor having an antiferromagnetic (AFM) layer recessed behind a bottom shield to reduce reader shield spacing and improve pin related noise. An AP/AFM coupling layer/APstack that extends from an air bearing surface to the MR sensor backside is formed above the AFM layer. The APlayer is pinned by the AFM layer, and the APlayer serves as a reference layer to an overlying free layer during a read operation. The APand APlayers have improved resistance to magnetization flipping because back portions thereof have a full cross-track width 'w' between MR sensor sides thereby enabling greater pinning strength from the AFM layer. Front portions of the AP/APlayers lie under the free layer and have a track width less than 'w'. The bottom shield may have an anti-ferromagnetic coupling structure.

Magnetic reader sensor with shield spacing improvement and better pin flip robustness

Growing community of inventors

Dublin, CA, United States of America

Min Li