Shengwu D Chang

7138768, Nov 21, 2006

May 23, 2002

10/154232

Peter E. Maciejowski - Amesbury MA, US
Joseph C. Olson - Beverly MA, US
Shengwu Chang - Newburyport MA, US
Bjorn O. Pedersen - Chelmsford MA, US
Daniel Distaso - Merrimac MA, US
Curt D. Bergeron - Danvers MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 7/24

31511181, 250427

An indirectly heated cathode ion source includes an arc chamber housing that defines an arc chamber, an indirectly heated cathode and a filament for heating the cathode. The cathode may include an emitting portion having a front surface, a rear surface and a periphery, a support rod attached to the rear surface of the emitting portion, and a skirt extending from the periphery of the emitting portion. A cathode assembly may include the cathode, a filament and a clamp assembly for mounting the cathode and the filament in a fixed spatial relationship and for conducting electrical energy to the cathode and the filament. The filament is positioned in a cavity defined by the emitting portion and the skirt of the cathode. The ion source may include a shield for inhibiting escape of electrons and plasma from a region outside the arc chamber in proximity to the filament and the cathode.

7253423, Aug 7, 2007

May 24, 2005

11/135307

Shengwu Chang - South Hamilton MA, US
Joseph C. Olson - Beverly MA, US
Damian Brennan - Gloucester MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 37/302

25049221, 25044211, 250398, 250396, 315506

A technique for uniformity tuning in an ion implanter system is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for uniformity tuning in an ion implanter system. The method may comprise measuring an ion beam at a plurality of predetermined locations along a beam path. The method may also comprise calculating an ion beam profile along the beam path based at least in part on the ion beam measurements at the plurality of predetermined locations. The method may further comprise determining a desired velocity profile along the beam path based at least in part on the calculated ion beam profile such that the ion beam, when scanned according to the desired velocity profile, produces a desired ion beam profile along the beam path.

7355188, Apr 8, 2008

Dec 15, 2005

11/300425

Joseph C. Olson - Beverly MA, US
Jonathan Gerald England - Horsham, GB
Morgan D. Evans - Manchester MA, US
Douglas Thomas Fielder - Peabody MA, US
Gregg Alexander Norris - Rockport MA, US
Shengwu Chang - South Hamilton MA, US
Damian Brennan - Gloucester MA, US
William Gray Callahan - Rockport MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 37/317

25049221, 25044211, 250398, 250396, 315506

A technique for uniformity tuning in an ion implanter system is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for ion beam uniformity tuning. The method may comprise generating an ion beam in an ion implanter system. The method may also comprise tuning one or more beam-line elements in the ion implanter system to reduce changes in a beam spot of the ion beam when the ion beam is scanned along a beam path. The method may further comprise adjusting a velocity profile for scanning the ion beam along the beam path such that the ion beam produces a substantially uniform ion beam profile along the beam path.

7397047, Jul 8, 2008

May 6, 2005

11/123082

Shengwu Chang - South Hamilton MA, US
Joseph C. Olson - Beverly MA, US
Damian Brennan - Gloucester MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 37/302

25049221, 25049222, 2504922, 438 10

A technique for tuning an ion implanter system is disclosed. In one particular exemplary embodiment, the technique may be realized as a method for tuning an ion implanter system having multiple beam-line elements. The method may comprise establishing one or more relationships among the multiple beam-line elements. The method may also comprise adjusting the multiple beam-line elements in a coordinated manner, based at least in part on the one or more established relationships, to produce a desired beam output.

7442944, Oct 28, 2008

Oct 7, 2004

10/960904

Shengwu Chang - South Hamilton MA, US
Antonella Cucchetti - Beverly MA, US
Joseph P. Dzengeleski - Newton NH, US
Gregory R. Gibilaro - Topsfield MA, US
Rosario Mollica - Wilmington MA, US
Gregg A. Norris - Rockport MA, US
Joseph C. Olson - Beverly MA, US
Marie J. Welsch - Georgetown MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 37/317

25049221, 2504922, 250397, 250396 R

An ion beam tuning method, system and program product for tuning an ion implanter system are disclosed. The invention obtains an ion beam profile of the ion beam by, for example, scanning the ion beam across a profiler that is within an implant chamber; and tunes the ion implanter system to maximize an estimated implant current based on the ion beam profile to simultaneously optimize total ion beam current and ion beam spot width, and maximize implant current. In addition, the tuning can also position the ion beam along a desired ion beam path based on the feedback of the spot beam center, which improves ion implanter system productivity and performance by reducing ion beam setup time and provides repeatable beam angle performance for each ion beam over many setups.

7459692, Dec 2, 2008

Nov 10, 2005

11/272193

Anthony Renau - West Newbury MA, US
Joseph C. Olson - Beverly MA, US
Shengwu Chang - South Hamilton MA, US
James Buff - Brookline NH, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 1/50

250396ML, 250396 R, 250400, 25049221

A method and apparatus are disclosed for improving space charge neutralization adjacent a magnet of an ion implanter by confining the electrons inside a magnetic region thereof to reduce electron losses and therefore improve the transport efficiency of a low energy beam. A magnetic pole member for a magnet of an ion implanter is provided that includes an outer surface having a plurality of magnetic field concentration members that form magnetic field concentrations adjacent the magnetic pole member. Electrons that encounter this increased magnetic field are repelled back along the same magnetic field line rather than allowed to escape. An analyzer magnet and ion implanter including the magnet pole are also provided so that a method of improving low energy ion beam space charge neutralization in an ion implanter is realized.

7462844, Dec 9, 2008

Sep 30, 2005

11/241406

Shengwu Chang - South Hamilton MA, US
Isao Tsunoda - Kanagawa-ken, JP
Dennis Rodier - Francestown NH, US
Joseph C. Olson - Beverly MA, US
Donna Smatlak - Belmont MA, US
Damian Brennan - Gloucester MA, US
William Bintz - Londonderry NH, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

H01J 37/08

25049221

The invention provides a method, system, and apparatus for improving doping uniformity during ion implantation, particularly during a high-tilt ion implantation. In one embodiment, the invention provides a method for improving doping uniformity in a high-tilt ion implantation, the method comprising the steps of: positioning a wafer along an axis perpendicular to an ion beam scan plane to form an angle between a surface of the wafer and a plane perpendicular to the ion beam; measuring a current of the ion beam by moving a current detector across the ion beam in a path substantially coplanar with a surface of the wafer; and adjusting a doping uniformity of the ion beam current based on the measuring step.

7622724, Nov 24, 2009

Jun 25, 2007

11/767657

Shengwu Chang - Hamilton MA, US
Frank Sinclair - Quincy MA, US

Varian Semiconductor Equipment Associates, Inc. - Gloucester MA

G21K 5/00

25049221, 2504921, 2504922, 25049222, 25049223

A high voltage insulator for preventing instability in an ion implanter due to triple junction breakdown is described. In one embodiment, there is an apparatus for preventing triple junction instability in an ion implanter. In this embodiment, there is a first metal electrode and a second metal electrode. An insulator is disposed between the first metal electrode and the second metal electrode. The insulator has at least one surface between the first metal electrode and the second metal electrode that is exposed to a vacuum that transports an ion beam generated by the ion implanter. A first conductive layer is located between the first metal electrode and the insulator. The first conductive layer prevents triple junction breakdown from occurring at an interface of the first electrode, insulator and vacuum. A second conductive layer is located between the second metal electrode and the insulator opposite the first conductive layer. The second conductive layer prevents triple junction breakdown from occurring at an interface of the second electrode, insulator and vacuum.