Wenyu S Chen, 44Buena Park, CA

8451567, May 28, 2013

Dec 13, 2010

12/928473

Yuchen Zhou - San Jose CA, US
Wenyu Chen - Newark CA, US
Joe Smyth - Aptos CA, US

Headway Technologies, Inc. - Milpitas CA

G11B 5/39

36032412, 2960314, 2960316

A CPP (Current Perpendicular to Plane) MR (Magnetoresistive) read head and its method of fabrication includes a patterned CPP MR sensor stack having a SAF (Synthetic Antiferromagnetic) free layer structure that is longitudinally biased by the combination of an exchange biasing layer formed over the sensor stack and hard biasing layers that are formed adjacent to the patterned sides of the stack. The combination provides the stack with high resolution reading capabilities without the necessity for a narrow read gap formed by closely spaced top and bottom shields. Sixteen embodiments are described that provide different versions of the exchange biasing layer, different positions of the hard biasing layers and different patternings of the CPP MR sensor stack.

8582240, Nov 12, 2013

Aug 29, 2012

13/597472

Wenyu Chen - San Jose CA, US
Joe Smyth - Aptos CA, US

Headway Technologies, Inc. - Milpitas CA

G11B 5/127

3601253

A design is disclosed for a microwave assisted magnetic recording device wherein direct current and rf current are simultaneously injected from a bias tee into a spin transfer oscillator (STO) between a main pole and write shield to improve the assist process. The STO oscillation layer (OL) has a large angle magnetization oscillation frequency that is locked to a magnetic medium bit resonance frequency f0 when the rf current has a frequency f=f0 and a threshold current density is applied. Alternatively, the OL magnetization oscillation frequency may be adjusted closer to f0 to improve the assist process. A third advantage is lowering the threshold current density when both direct current and rf current are injected into the STO during a write process. The main pole is grounded when direct current and rf current are injected into a write shield.

2011014, Jun 23, 2011

Dec 17, 2009

12/640081

Wenyu Chen - San Jose CA, US
Sylvia H. Florez Marino - San Jose CA, US
Liesl Folks - Campbell CA, US
Bruce D. Terris - Sunnyvale CA, US

G11C 11/00
G11C 11/416

365130, 365158, 36518916, 36518915

A three-dimensional nonvolatile memory array device includes a plurality of memory elements and a memory controller. The plurality of memory elements each have a stack of a plurality of bits, which in turn each include a magnetic free layer, a magnetic pinned layer, and a non-magnetic layer. The magnetic free layer is configured to alternate its magnetization orientation based on a radio frequency current being at a resonant frequency of the magnetic free layer and on a magnetic field being applied to the magnetic free layer. The magnetic pinned layer has a specific magnetization orientation. The non-magnetic layer is located in between the magnetic free layer and the magnetic pinned layer. The memory controller is in communication with each of the plurality of memory elements, and configured to write data to and read data from the plurality of bits in the memory elements.

2022033, Oct 20, 2022

Jul 1, 2022

17/856585

- Milpitas CA, US
Yan Wu - Cupertino CA, US
Wenyu Chen - San Jose CA, US
Kunliang Zhang - Fremont CA, US
Min Li - Fremont CA, US
Shohei Kawasaki - Sunnyvale CA, US

G11B 5/39

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.

2022019, Jun 23, 2022

Mar 10, 2022

17/691869

- Milpitas CA, US
Shohei Kawasaki - Sunnyvale CA, US
Wenyu Chen - San Jose CA, US
Yuhui Tang - Milpitas CA, US

G11B 5/31
G11B 5/127
G11B 5/23
G11B 5/235

A method of forming a spin transfer torque reversal assisted magnetic recording (STRAMR) writer is disclosed wherein a spin torque oscillator (STO) has a flux guiding layer (FGL) wherein magnetization flips to a direction substantially opposing the write gap (WG) field when sufficient current (I) density is applied across the STO between a trailing shield and main pole (MP) thereby enhancing the MP write field. The FGL has a center portion with a larger magnetization saturation×thickness (MsT) than in FGL outer portions proximate to STO sidewalls. Accordingly, lower Idensity is necessary to provide a given amount of FGL magnetization flipping and there is reduced write bubble fringing compared with writers having a FGL with uniform MsT. Lower MsT is achieved by partially oxidizing FGL outer portions. In some embodiments, there is a gradient in outer FGL portions where MsT increases with increasing distance from FGL sidewalls.

2021014, May 13, 2021

Jul 2, 2020

16/919936

- Milpitas CA, US
Wenyu Chen - San Jose CA, US

G11B 5/31
G11B 5/37
G11B 5/127
G01R 33/09

A Spin Hall Effect (SHE) assisted magnetic recording device is disclosed wherein a SHE layer and a conductor layer (CL) are formed between a main pole (MP) trailing side and a trailing shield (TS). When the SHE layer is a negative Spin Hall Angle (SHA) material, current (I) flows from the SHE layer across the CL to a lead back to a source, or across the CL to one of the MP and TS. For a SHE layer with a positive SHA material, Ia flows from one of the MP or TS or from a lead across the CL to the SHE layer. Spin polarized current in the SHE layer applies spin transfer torque that tilts a local MP magnetization to a direction that enhances a MP write field, or that tilts a local TS magnetization to a direction that increases the TS return field and improves bit error rate.

2018013, May 10, 2018

Oct 23, 2017

15/790342

- Milpitas CA, US
Yewhee Chye - Hayward CA, US
Wenyu Chen - San Jose CA, US
Kunliang Zhang - Fremont CA, US
Yan Wu - Cupertino CA, US
Min Li - Fremont CA, US

G11B 5/39

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 AP2/AFM coupling layer/AP1 stack that extends from an air bearing surface to the MR sensor backside is formed above the AFM layer. 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.

2017030, Oct 19, 2017

Apr 14, 2016

15/098913

- Milpitas CA, US
Ruhang Ding - Pleasanton CA, US
Min Li - Fremont CA, US
Wenyu Chen - San Jose CA, US

H01L 43/02
H01L 43/10
H01L 43/08
H01L 43/12
G11C 11/16

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.