Headway Technologies, Incorporated

Kabushiki Kaisha Toshiba

Tdk Corporation

Ruhang Ding

Min Li

Kunliang Zhang

Wenyu Chen

Jianing Zhou

Yewhee Chye

Tom Zhong

Cherng Chyi Han

Minghui Yu

Hiroshi Omine

Satoshi Shirotori

Katsuhiko Koui

Yan Wu

Hui-Chuan Wang

Glen A Garfunkel

Junjie Quan

Norihito Fujita

Akihiki Takeo

Shinobou Sugimura

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

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 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

A MR sensor is disclosed with an antiferromagnetic (AFM) layer recessed behind a bottom shield to reduce reader shield spacing and improve pin related noise. Above the AFM layer is an AP2/AFM coupling layer/AP1 stack that extends from an air bearing surface to the MR sensor backside. The AP2 layer is pinned by the AFM layer, and the AP1 layer serves as a reference layer to an overlying free layer during a read operation. The AP1 and AP2 layers 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 AP1/AP2 layers lie under the free layer and have a track width less than 'w'. The bottom shield may have an anti-ferromagnetic coupling structure. A process flow is provided for fabricating the MR sensor.

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

A MR sensor is disclosed with an antiferromagnetic (AFM) layer recessed behind a first stack of layers including a free layer and non-magnetic spacer to reduce reader shield spacing and enable increased areal density. The AFM layer may be formed on a first pinned layer in the first stack that is partially embedded in a second pinned layer having a front portion at an air bearing surface (ABS) to improve pinning strength and avoid a morphology effect. In another embodiment, the AFM layer is embedded in a bottom shield and surrounds the sidewalls and back side of an overlying free layer in the sensor stack to reduce reader shield spacing. Pinning strength is improved because of increased contact between the AFM layer and a pinned layer. The free layer is aligned above a bottom shield center section.

Reader designs of shield to shield spacing improvement

A TMR (tunneling magnetoresistive) read sensor is formed in which a portion of the sensor stack containing the ferromagnetic free layer and the tunneling barrier layer is patterned to define a narrow trackwidth, but a synthetic antiferromagnetic pinning/pinned layer is left substantially unpatterned and extends in substantially as-deposited form beyond the lateral edges bounding the patterned portion. The narrow trackwidth of the patterned portion permits high resolution for densely recorded data. The larger pinning/pinned layer significantly improves magnetic stability and reduces thermal noise, while the method of formation eliminates possible ion beam etch (IBE) or reactive ion etch (RIE) damage to the edges of the pinning/pinned layer.

Reader sensor structure and its method of construction

A two part ion beam etch sequence involving low energy (&#x3c;300 eV) is disclosed for fabricating a free layer width (FLW) as small as 20-25 nm in a MTJ element. A first etch process has one or more low incident angles and accounts for removal of 70% to 100% of the MTJ stack that is not covered by an overlying photoresist layer. The second etch process employs one or more high incident angles and a sweeping motion that is repeated during a plurality of cycles. Sidewall slope may be adjusted by varying the incident angle during either of the etch processes. FLW is about 30 nm less than an initial critical dimension in the photoresist layer while maintaining a MR ratio over 60% and low RA (resistance&#xd7;area) value of 1.0 ohm-&#x3bc;m.

Two step method to fabricate small dimension devices for magnetic recording applications

According to one embodiment, a magnetic recording head manufacturing method includes forming a spin torque oscillator layer on a main magnetic pole layer, forming a mask on the spin torque oscillator layer, processing the spin torque oscillator layer by performing ion beam etching through the mask, and partially modifying the main magnetic pole layer through the mask. The partially modifying the main magnetic pole layer makes it possible to decrease the saturation flux density of the main magnetic pole layer in the modified portion, and form an unmodified main magnetic pole portion covered with the mask, and a modified portion around the main magnetic pole.

Microwave-assisted magnetic recording head, method of manufacturing the same, magnetic head assembly using the same, and magnetic recording/reproduction apparatus

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Pleasanton, CA, United States of America

Ruhang Ding