Thomas H Chang

US Patent:

6339872, Jan 22, 2002

Filed:

May 3, 2000

Appl. No.:

09/564155

Inventors:

Thomas Young Chang - San Jose CA
Edward Hinpong Lee - San Jose CA
Jyh-Shuey Jerry Lo - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 542

US Classification:

2960314, 2960315, 216 22, 216 66, 360317

Abstract:

A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head.

US Patent:

6355524, Mar 12, 2002

Filed:

Aug 15, 2000

Appl. No.:

09/640139

Inventors:

Hsing Ti Tuan - Cupertino CA
Li-Chun Li - Los Gatos CA
Chung Wai Leung - Milpitas CA
Thomas Tong-Long Chang - Santa Clara CA

Assignee:

Mosel Vitelic, Inc. - Hsin Chu

International Classification:

H01L 21336

US Classification:

438257

Abstract:

In a nonvolatile memory, select gates are self-aligned spacers formed on sidewalls of floating/control gate stacks. The same mask ( ) is used to remove the select gate layer from over the source lines ( ), to etch trench insulation in the source line regions, and to dope the source lines. The memory can be formed in and over an isolated substrate region. The source lines can be doped at least partially before the trench insulation is etched, to prevent a short before the source lines and a region isolating the isolated substrate region from below. The memory can be erased by sectors, or alternatively a chip erase operation can be performed to erase all the cells in parallel. Peripheral transistor gates can be formed from the same layer as the select gates. The select gate spacers have extensions to which low resistance contacts can be made from overlying metal lines.

US Patent:

6407891, Jun 18, 2002

Filed:

May 24, 1999

Appl. No.:

09/317808

Inventors:

Thomas Young Chang - San Jose CA
Shanlin Duan - Fremont CA
Terence Tin-Lok Lam - San Jose CA
Wai C. Leung - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

360317, 360319

Abstract:

The present invention is a read/write head for writing information to magnetic media and reading information from magnetic media. It includes a write head for writing information onto magnetic media, a read head for reading information from the magnetic media, and an electrical circuit element that is disposed proximate the read head that functions to generate an electromagnetic field at the read head that is generally oppositely directed to the electromagnetic field generated by the write head. The method for operating the read/write head in a hard disk drive, includes the steps of writing data onto a hard disk, while simultaneously generating an electromagnetic field at the read head that is directed oppositely to the electromagnetic field generated by the write head.

US Patent:

6473276, Oct 29, 2002

Filed:

Nov 24, 2000

Appl. No.:

09/721850

Inventors:

Thomas Young Chang - San Jose CA
Edward Hinpong Lee - San Jose CA
Jyh-Shuey Jerry Lo - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 539

US Classification:

360317, 360126, 360122

Abstract:

A single-sided, notched write head is provided for writing narrow erase band servo tracks as well as a double-notched write head, and for writing data tracks better than a double-notched write head. The single-sided, notched write head writes a narrow erase band on the notched side and a wide erase band on the unnotched side. In one embodiment, only one side of the first pole piece layer is notched, and in another embodiment a first side of the first pole piece layer is notched more than a second side. By writing servo tracks only a fraction of the track width of the write head, a wide erase band region is overwritten so that a narrow erase band is on each side of the servo track. Data tracks are written with a narrow erase band on one side and a wide erase band on the other side. The wide erase band on one side of the data track allows more flexibility in spacing the read head from adjacent tracks. The single-sided, notched write head can be manufactured with methods that require less processing time than a double-notched write head.

US Patent:

6477008, Nov 5, 2002

Filed:

May 24, 1999

Appl. No.:

09/317668

Inventors:

Thomas Young Chang - San Jose CA
Shanlin Duan - Fremont CA
Terence Tin-Lok Lam - San Jose CA
Wai C. Leung - San Jose CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 5115

US Classification:

360128, 360126, 360317

Abstract:

The present invention is a read/write head for writing information to magnetic media and reading information from magnetic media. It includes a write head element for writing information onto magnetic media, a read head element for reading information from the magnetic media, and an electromagnetic field shield element that is disposed between the write head element and the read head element. The shield functions to shield the read head from electromagnetic field energy created by the write head element. An enhanced second embodiment includes an electrical circuit element that is disposed proximate the read head element that functions to generate an electromagnetic field at the read head element that is generally oppositely directed to the electromagnetic field generated by the write head element to reduce the total electromagnetic field that the read head element is exposed to during a writing operation. The method for operating the read/write head in a hard disk drive, includes the steps of writing data onto a hard disk and reading data from the hard disk simultaneously with the data writing. This is accomplished by shielding the read head from the electromagnetic field energy generated during the data writing by utilizing the electromagnetic field shield element that is disposed between the write head element and the said read head element.

US Patent:

6521902, Feb 18, 2003

Filed:

Aug 15, 2000

Appl. No.:

09/638507

Inventors:

Thomas Young Chang - Menlo Park CA
Michael Andrew Parker - Fremont CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H01J 3708

US Classification:

25049221, 2504923, 20429836, 2960313

Abstract:

The improved method for trimming a magnetic head utilizing a FIB tool includes a step of aligning the FIB tool milling boxes without imaging critical pole tip components and structure. The method includes the creation of an alignment box that is disposed in a known, fixed orientation relative to the FIB tool milling boxes. The FIB tool is aligned by imaging only the alignment box and by moving the alignment box relative to known pole tip structural characteristics that are disposed away from the critical pole tip components. The alignment box is visually aligned on non-sensitive pole tip components in such a manner that the milling boxes will be properly aligned relative to the sensitive pole tip components. FIB tool milling is thereafter performed within the milling boxes which have been accurately aligned without imaging of sensitive pole tip components.

US Patent:

6542331, Apr 1, 2003

Filed:

Apr 10, 2000

Appl. No.:

09/546576

Inventors:

Thomas Young Chang - Menlo Park CA
Terence Tin-Lok Lam - San Jose CA
Edward HinPong Lee - San Jose CA
Samuel Wonder Yuan - Saratoga CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 531

US Classification:

360126, 360123

Abstract:

The magnetic head of the present invention includes a P pole having an opening formed therethrough, and a P pole that is formed over the opening. A second magnetic pole tip is positioned relative to the first magnetic pole such that the first magnetic pole is symmetrically disposed relative to the second magnetic pole tip. Induction coils may be helically wound around portions of the first and/or second magnetic poles, or, alternatively, a planar, spiral induction coil may be fabricated for use with the first and second magnetic poles. An enhanced embodiment includes a first magnetic pole tip piece having a length that defines the throat length of the magnetic head and a thickness that increases the gap at rearward portions of the second magnetic pole tip of the magnetic head.

US Patent:

6584676, Jul 1, 2003

Filed:

May 2, 2000

Appl. No.:

09/561659

Inventors:

Yu-En Percy Chang - Mountain View CA
Thomas Young Chang - San Jose CA
Michael A. Parker - Fremont CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

G11B 5127

US Classification:

2960312, 2960307, 2960313, 2960315, 216 22, 360126

Abstract:

A method for finishing a pole tip trimmed read/write heat that includes a substrate with a pole tip structure having a shield, a shield/pole, and an outer pole. A gap region separates the pole and the shield/pole. First, pole tip trimming is performed to the read/write head to remove matter from the shield/pole, the pole, and the gap region. This defines a bridge composed of inward-facing extensions of the pole and shield/pole interconnected by an intervening region. This bridge separates recessed âtrenches,â each formed by removing a contiguous mass from the shield/pole, the gap region, and the pole. Next, an overlayer is applied over the pole tip structure, filling the recessed trenches. The coated structure is then trimmed to remove all coating material overlying the shield/pole and pole. Trimming is continued to additionally remove a top layer of the protrusions of the pole and shield/pole to remove any rounded edges created by pole tip patterning, resulting in a more distinct write head.