Patents by Inventor Nobuhiro Tokoro

Nobuhiro Tokoro 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).

  • Particle beam current monitoring technique
    Patent number: 6541780
    Abstract: A method of monitoring particle beam current in an ion implanter in which the ion beam is analyzed to separate it into a separate sub-beam for each ion charge state. At least one sub-beam, having a charge state different from the desired charge state, is intercepted, and the current of the intercepted sub-beam is measured. This current is useful as an estimate of the current of the desired sub-beam which is used for the implantation.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: April 1, 2003
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Steven L. F. Richards, Nobuhiro Tokoro
  • Charge exchange cell
    Patent number: 5838012
    Abstract: A charge exchange cell for ion implanters employing a tandem accelerator has a hollow-wall construction with a heating element inserted inside the hollow wall.
    Type: Grant
    Filed: March 19, 1997
    Date of Patent: November 17, 1998
    Assignee: Genus, Inc.
    Inventors: Marvin LaFontaine, Nobuhiro Tokoro, Victor Quattrini, Daniel Bissonnette, Takao Sakase
  • Method of monitoring ion beam current in ion implantation apparatus for use in manufacturing semiconductors
    Patent number: 5319212
    Abstract: In ion implantation apparatus, a pair of electrodes is positioned about the ion beam near the place where ions strike the target in which they are implanted. One electrode has a positive potential applied to it, and the electron current collected at this electrode is measured. The other electrode has a negative potential applied to it, and the positive ion current collected at this electrode is separately measured. The magnitude of the two currents are added together and used as a signal to compensate for reduction in beam current collected caused by charge exchange phenomena.
    Type: Grant
    Filed: October 7, 1992
    Date of Patent: June 7, 1994
    Assignee: Genus, Inc.
    Inventor: Nobuhiro Tokoro
  • Ion accelerator
    Patent number: 5300891
    Abstract: Ion accelerator characterized in that it is able to use not only a negative ion beam, but also a positive ion beam and a neutral beam, increases the efficiency of the use of the beam, and increases beam current, by using a positive ion source and a charge exchange cell, producing a negative ion beam, and providing, in a tandem type accelerator which uses this, a pre-analyzing magnet having changeable polarity and a pre-focusing lens, a beam neutralizer, and an accelerator terminal, shorting rod.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: April 5, 1994
    Assignee: Genus, Inc.
    Inventor: Nobuhiro Tokoro
  • Ion source
    Patent number: 5162699
    Abstract: An ion source of high ion yield, especially boron yield, is provided with a boron compound of high melting point and low work function such as LaB.sub.6 (lanthanum hexaboride) at a suitable location inside the arc chamber of the ion source, which operates on the principle of ion production by using a hot cathode to produce hot electrons.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: November 10, 1992
    Assignee: Genus, Inc.
    Inventors: Nobuhiro Tokoro, Richard C. Becker