Patents by Inventor Shengwu Chang

Shengwu Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7138768
    Abstract: 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.
    Type: Grant
    Filed: May 23, 2002
    Date of Patent: November 21, 2006
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Peter E. Maciejowski, Joseph C. Olson, Shengwu Chang, Bjorn O. Pedersen, Leo V. Klos, Jr., Daniel Distaso, Curt D. Bergeron
  • Publication number: 20060249696
    Abstract: 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.
    Type: Application
    Filed: May 6, 2005
    Publication date: November 9, 2006
    Inventors: Shengwu Chang, Joseph Olson, Damian Brennan
  • Publication number: 20060169911
    Abstract: 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.
    Type: Application
    Filed: November 10, 2005
    Publication date: August 3, 2006
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Anthony Renau, Joseph Olson, Shengwu Chang, James Buff
  • Publication number: 20060169922
    Abstract: A system, method and program product for controlling parallelism and/or direction integrity of an ion beam generated by an ion implanter system are disclosed. The invention utilizes multiple faraday cups to measure a profile of at least a portion of the ion beam. The results of the measurement are then processed to determine parallelism and/or direction integrity of the ion beam. The results of the parallelism and/or direction integrity determination are then used to adjust the ion implanter system operating parameters to control parallelism and the direction of the ion beam.
    Type: Application
    Filed: October 7, 2005
    Publication date: August 3, 2006
    Inventors: Shengwu Chang, Joseph Olson, Damian Brennan
  • Publication number: 20060108543
    Abstract: A method and apparatus for weakening a strong focus effect of an acceleration-deceleration column of an ion implanter during a deceleration mode are disclosed. The apparatus includes a tube lens surrounding the ion beam adjacent to a deceleration lens of the acceleration-deceleration column. The tube lens causes a defocusing of the ion beam at the entrance of the tube lens, which reduces the ion dispersion problem generated by the column. The invention also includes an accel-decel column and ion implanter incorporating the tube lens. An additional deceleration-suppression electrode may also be added subsequent to the tube lens for confining electrons within the tube lens.
    Type: Application
    Filed: November 19, 2004
    Publication date: May 25, 2006
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Shengwu Chang, Joseph Olson, Donald Anderson, Daniel McGillicuddy
  • Patent number: 7045799
    Abstract: A method and apparatus for weakening a strong focus effect of an acceleration-deceleration column of an ion implanter during a deceleration mode are disclosed. The apparatus includes a tube lens surrounding the ion beam adjacent to a deceleration lens of the acceleration-deceleration column. The tube lens causes a defocusing of the ion beam at the entrance of the tube lens, which reduces the ion dispersion problem generated by the column. The invention also includes an accel-decel column and ion implanter incorporating the tube lens. An additional deceleration-suppression electrode may also be added subsequent to the tube lens for confining electrons within the tube lens.
    Type: Grant
    Filed: November 19, 2004
    Date of Patent: May 16, 2006
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Shengwu Chang, Joseph C. Olson, Donald Anderson, Daniel McGillicuddy
  • Publication number: 20060076510
    Abstract: 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.
    Type: Application
    Filed: October 7, 2004
    Publication date: April 13, 2006
    Inventors: Shengwu Chang, Antonella Cucchetti, Joseph Dzengeleski, Gregory Gibilaro, Rosario Mollica, Gregg Norris, Joseph Olson, Marie Welsch
  • Publication number: 20030218428
    Abstract: 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.
    Type: Application
    Filed: May 23, 2002
    Publication date: November 27, 2003
    Inventors: Peter E. Maciejowski, Joseph C. Olson, Shengwu Chang, Bjorn O. Pedersen, Leo V. Klos, Daniel Distaso, Curt D. Bergeron