Po Shun Wang

D483079, Dec 2, 2003

Jan 23, 2003

29/174725

Po Szu Wang - Irvine CA, 92620
Josephine M. Yang - Buena Park CA, 90620

2101

D21433, D21425, D21427

6677105, Jan 13, 2004

May 4, 2001

09/848589

Po Wen Wang - San Jose CA
Evan F. Cromwell - Redwood City CA
Olu Atanda - Campbell CA

Toda Kogyo Corporation - Hiroshima-ken

G11B 1100

4302711, 43077011, 430945, 428 643, 428 646, 2041922, 20419226, 369 1338

A silicon nitride self-lubricating layer forms the upper surface of a data storage device, such as a rotating disk or a non-rotating memory device, e. g. , a credit card-type memory device using a memory strip. The silicon nitride self-lubricating layer can replace the carbon protective overcoat and liquid lubricant used in conventional data storage devices. The silicon nitride self-lubrication layer provides the desired lubrication and protection between the slider and the data storage device. The silicon nitride layer also will not evaporate under high temperatures found in an optical data storage system. In addition, a data storage device may include a plastic polymer layer over which an iron oxide material is deposited. The use of a plastic polymer layer and iron oxide recording layer is particularly advantageous because a low temperature deposition process can be used with the iron oxide material.

6760966, Jul 13, 2004

Apr 30, 2002

10/135097

Po Kang Wang - San Jose CA
Moris Dovek - San Jose CA
Jibin Geng - Milpitas CA
Tai Min - San Jose CA

Headway Technologies, Inc. - Milpitas CA

G11B 5147

2960314, 2960313, 2960307, 36032412, 360322, 427128, 427131, 148108

As track density requirements for disk drives have grown more aggressive, GMR devices have been pushed to narrower track widths to match the track pitch of the drive width. Narrower track widths degrade stability, cause amplitude loss, due to the field originating from the hard bias structure, and side reading. This problem has been overcome in a process of manufacturing a device by adding an additional layer of soft magnetic material above the hard bias layers. The added layer provides flux closure to the hard bias layers thereby preventing flux leakage into the gap region. A non-magnetic layer must be included to prevent exchange coupling to the hard bias layers. In at least one embodiment the conductive leads are used to accomplish this.

6929957, Aug 16, 2005

Sep 12, 2003

10/661039

Tai Min - San Jose CA, US
Po Kang Wang - San Jose CA, US

Headway Technologies, Inc. - Milpitas CA

H01L021/00

438 3, 438595, 438737

A magnetic tunneling junction (MTJ) memory cell and an MRAM array of such cells, is shielded by magnetic shields of ferromagnetic material or by ferromagnetic shields that are stabilized by patterned layers of antiferromagnetic material or permanent magnetic material. The ferromagnetic portions of the shields surround the MTJ cells substantially conformally and thereby can compensate the poles of the free layers of MTJ cells of various geometric cross-sectional shapes and also protect the cells from the adverse effects of extraneous fields. The additional antiferromagnetic and permanent magnetic materials stabilize the shields by exchange or direct coupling.

6943040, Sep 13, 2005

Aug 28, 2003

10/650600

Tai Min - San Jose CA, US
Po Kang Wang - Milpitas CA, US

Headway Technologes, Inc. - Milpitas CA

H01L021/00

438 3, 365 55, 365 66, 365171, 365173, 3652255, 36523003, 438673

A magnetic tunneling junction (MTJ) memory cell for a magnetic random access memory (MRAM) array is formed as a chain of magnetostatically coupled segments. The segments can be circular, elliptical, lozenge shaped or shaped in other geometrical forms. Unlike the isolated cells of typical MTJ designs which exhibit curling of the magnetization at the cell ends and uncompensated pole structures, the present multi-segmented design, with the segments being magnetostatically coupled, undergoes magnetization switching at controlled nucleation sites by the fanning mode. As a result, the multi-segmented cells of the present invention are not subject to variations in switching fields due to shape irregularities and structural defects.

6960281, Nov 1, 2005

Mar 21, 2003

10/394098

Po Kang Wang - San Jose CA, US
Fenglin Liu - Fremont CA, US

Headway Technologies, Inc. - Milpitas CA

C23C014/34

20419234, 427130, 427131, 427132

A method for forming a trimmed upper pole piece for a magnetic write head, said pole piece having a tapered profile that is widest at its trailing edge. Such a pole piece is capable of writing narrow tracks with sharply and well defined patterns and minimal overwriting of adjacent tracks. The present method produces the necessary taper by using NiCr, NiFeCr, Rh or Ru as write gap filling materials which have an etch rate which is substantially equal to the etch rate of the other layers forming the pole piece and are highly corrosion resistant. As a result, the write gap does not protrude to mask the effects of the ion-beam etch used to form the taper.

7029941, Apr 18, 2006

Aug 25, 2003

10/647716

Tai Min - San Jose CA, US
Po Kang Wang - San Jose CA, US

Headway Technologies, Inc. - Milpitas CA

H01L 21/00

438 48, 257421, 257E27006, 257295

An MRAM array is formed of MTJ cells shaped so as to have their narrowest dimension at the middle of the cell. A preferred embodiment forms the cell into the shape of a kidney or a peanut. Such a shape provides each cell with an artificial nucleation site at the narrowest dimension, where an applied switching field can switch the magnetization of the cell in manner that is both efficient and uniform manner across the array.

7047625, May 23, 2006

Aug 25, 2003

10/647762

Po Kang Wang - San Jose CA, US

Headway Technologies, Inc. - Milpitas CA

G11B 5/127
H04R 31/00

2960316, 295921, 2960312, 2960314, 2960315, 2960318, 360121, 360122, 360126, 360317, 427127, 427128, 451 4, 451 51

Present processes used for planarizing a cavity filled with a coil and hard baked photoresist require that a significant amount of the thickness of the coils be removed. This increases the DC resistance of the coil. In the present invention, cavity and coil are overfilled with photoresist which is then hard baked. A layer of alumina is then deposited onto the surface of the excess photoresist, following which CMP is initiated. The presence of the alumina serves to stabilize the photoresist so that it does not delaminate. CMP is terminated as soon as the coils are exposed, allowing their full thickness to be retained and resulting in minimum DC resistance.