Bo O Gu

US Patent:

6979798, Dec 27, 2005

Filed:

Feb 26, 2004

Appl. No.:

10/787517

Inventors:

Bo Gu - North Andover MA, US
Donald J. Svetkoff - Ann Arbor MI, US
Kurt Pelsue - Wayland MA, US

Assignee:

GSI Lumonics Corporation - Northville MI

International Classification:

B23K026/36

US Classification:

21912169, 21912168

Abstract:

Laser system and method for material processing with ultra fast lasers are provided. One aspect of the invention features the method which removes at least a portion of a target structure such as a memory link while avoiding undesirable damage to adjacent non-target structures. The method includes applying a single ultra short laser pulse to the target structure to remove the target structure with the single pulse.

US Patent:

7358157, Apr 15, 2008

Filed:

Oct 6, 2005

Appl. No.:

11/245282

Inventors:

Bo Gu - North Andover MA, US
Joseph V. Lento - Methuen MA, US
Jonathan S. Ehrmann - Sudbury MA, US
Bruce L. Couch - North Attleboro MA, US
Yun Fee Chu - Natick MA, US
Shepard D. Johnson - Andover MA, US

Assignee:

GSI Group Corporation - Billerica MA

International Classification:

H01L 21/00

US Classification:

438463, 438460, 257E21347

Abstract:

A method, system and scan lens system are provided for high-speed, laser-based, precise laser trimming at least one electrical element. The method includes generating a pulsed laser output having one or more laser pulses at a repetition rate. Each laser pulse has a pulse energy, a laser wavelength within a range of laser wavelengths, and a pulse duration. The method further includes selectively irradiating the at least one electrical element with the one or more laser pulses focused into at least one spot having a non-uniform intensity profile along a direction and a spot diameter as small as about 6 microns to about 15 microns so as to cause the one or more laser pulses to selectively remove material from the at least one element and laser trim the at least one element while avoiding substantial microcracking within the at least one element. The wavelength is short enough to produce desired short-wavelength benefits of small spot size, tight tolerance and high absorption, but not so short so as to cause microcracking.

US Patent:

7469831, Dec 30, 2008

Filed:

Oct 27, 2006

Appl. No.:

11/514660

Inventors:

Bo Gu - North Andover MA, US
Jonathan S. Ehrmann - Sudbury MA, US
Donald J. Svetkoff - Ann Arbor MI, US
Steven P. Cahill - Newton MA, US
Kevin E. Sullivan - Everett MA, US

Assignee:

GSI Group Corporation - Billerica MA

International Classification:

G06K 7/10

US Classification:

235454, 21912162, 438463

Abstract:

A laser-based method and system for processing targeted surface material and article produced thereby are provided. The system processes the targeted surface material within a region of a workpiece while avoiding undesirable changes to adjacent non-targeted material. The system includes a primary laser subsystem including a primary laser source for generating a pulsed laser output including at least one pulse having a wavelength and a pulse width less than 1 ns. A delivery subsystem irradiates the targeted surface material of the workpiece with the pulsed laser output including the at least one pulse to texture the targeted surface material. The pulsed laser output has sufficient total fluence to initiate ablation within at least a portion of the targeted surface material and the pulse width is short enough such that the region and the non-targeted material surrounding the material are substantially free of slag.

US Patent:

7563695, Jul 21, 2009

Filed:

Jan 25, 2007

Appl. No.:

11/657810

Inventors:

Bo Gu - North Andover MA, US
Jonathan S. Ehrmann - Sudbury MA, US
Joseph V. Lento - Methuen MA, US
Bruce L. Couch - North Attleboro MA, US
Yun Fee Chu - Natick MA, US
Shepard D. Johnson - Andover MA, US

Assignee:

GSI Group Corporation - Billerica MA

International Classification:

H01L 21/00

US Classification:

438463, 438460, 257E21347

Abstract:

A method, system and scan lens for use therein are provided for high-speed, laser-based, precise laser trimming at least one electrical element along a trim path. The method includes generating a pulsed laser output with a laser, the output having one or more laser pulses at a repetition rate. A fast rise/fall time, pulse-shaped q-switched laser or an ultra-fast laser may be used. Beam shaping optics may be used to generate a flat-top beam profile. Each laser pulse has a pulse energy, a laser wavelength within a range of laser wavelengths, and a pulse duration. The wavelength is short enough to produce desired short-wavelength benefits of small spot size, tight tolerance, high absorption and reduced or eliminated heat-affected zone (HAZ) along the trim path, but not so short so as to cause microcracking. In this way, resistance drift after the trimming process is reduced.

US Patent:

7705268, Apr 27, 2010

Filed:

Nov 9, 2005

Appl. No.:

11/270109

Inventors:

Bo Gu - North Andover MA, US
Jonathan S. Ehrmann - Sudbury MA, US

Assignee:

GSI Group Corporation - Bedford MA

International Classification:

B23K 26/36

US Classification:

21912169, 21912161, 21912168, 264400

Abstract:

Methods and systems for laser soft marking, especially for semiconductor wafers and devices, are provided. A laser-marking system for marking a semiconductor wafer to form a softmark on the wafer is provided. The system includes a laser subsystem for generating one or more laser pulses and a controller operatively connected to the laser subsystem. The controller sets a laser pulse width of the one or more laser pulses to selectively provide one or more laser output pulses having one or more set pulse widths that affect the depth of a softmark that is to be formed. The mark depth is substantially dependent on the one or more set pulse widths. The controller further sets a pulse energy of the one or more output pulses to selectively provide the one or more output pulses having a set total output energy that is within an acceptable process energy window for producing the softmark.

US Patent:

7723642, May 25, 2010

Filed:

Oct 10, 2003

Appl. No.:

10/683086

Inventors:

Bo Gu - North Andover MA, US
Donald V. Smart - Boston MA, US
James J. Cordingley - Littleton MA, US
Joohan Lee - Andover MA, US
Donald J. Svetkoff - Ann Arbor MI, US
Shepard D. Johnson - Andover MA, US
Jonathan S. Ehrmann - Sudbury MA, US

Assignee:

GSI Group Corporation - Bedford MA

International Classification:

B23K 26/36
B23K 26/40

US Classification:

21912168, 21912161

Abstract:

A laser-based method of removing a target link structure of a circuit fabricated on a substrate includes generating a pulsed laser output at a pre-determined wavelength less than an absorption edge of the substrate. The laser output includes at least one pulse having a pulse duration in the range of about 10 picoseconds to less than 1 nanosecond, the pulse duration being within a thermal laser processing range. The method also includes delivering and focusing the laser output onto the target link structure. The focused laser output has sufficient power density at a location within the target structure to reduce the reflectivity of the target structure and efficiently couple the focused laser output into the target structure to remove the link without damaging the substrate.

US Patent:

7732731, Jun 8, 2010

Filed:

Sep 13, 2007

Appl. No.:

11/900731

Inventors:

Bo Gu - North Andover MA, US

Assignee:

GSI Group Corporation - Bedford MA

International Classification:

B23K 26/00

US Classification:

21912169, 21912172, 21912168, 21912167

Abstract:

A method and system for laser processing targets of different types on a workpiece are provided. The method includes setting a laser pulse width of one or more laser pulses to selectively provide one or more laser output pulses having one or more set pulse widths based on a first type of target to be processed. The method further includes setting a pulse shape of the one or more output pulses to selectively provide the one or more output pulses having the set pulse shape based on the types of targets to be processed. The method still further includes delivering the one or more output pulses having the one or more set pulse widths and the set pulse shape to at least one target of the first type. The method finally includes resetting the laser pulse width of one or more laser pulses to selectively provide one or more laser output pulses having one or more reset pulse widths based on a second type of target to be processed.

US Patent:

7838794, Nov 23, 2010

Filed:

Jan 31, 2007

Appl. No.:

11/700386

Inventors:

Bo Gu - North Andover MA, US
Donald V. Smart - Boston MA, US
James J. Cordingley - Littleton MA, US
Joohan Lee - Andover MA, US
Donald J. Svetkoff - Ann Arbor MI, US
Shepard D. Johnson - Andover MA, US
Jonathan S. Ehrmann - Sudbury MA, US

Assignee:

GSI Group Corporation - Bedford MA

International Classification:

B23K 26/40
H01L 21/44

US Classification:

21912168, 438132

Abstract:

Laser-based methods and systems for removing one or more target link structures of a circuit fabricated on a substrate includes generating a pulsed laser output at a predetermined wavelength less than an absorption edge of the substrate are provided. The laser output includes at least one pulse having a pulse duration in the range of about 10 picoseconds to less than 1 nanosecond, the pulse duration being within a thermal laser processing range. The method also includes delivering and focusing the laser output onto the target link structure. The focused laser output has sufficient power density at a location within the target link structure to reduce the reflectivity of the target link structure and efficiently couple the focused laser output into the target link structure to remove the target link structure without damaging the substrate.