Patents by Inventor Charles M. McKenna

Charles M. McKenna 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: 6998625
    Abstract: An ion implanter includes an ion source for generating an ion beam, an analyzer for separating unwanted components from the ion beam, a first beam transport device for transporting the ion beam through the analyzer at a first transport energy, a first deceleration stage positioned downstream of the analyzer for decelerating the ion beam from the first transport energy to a second transport energy, a beam filter positioned downstream of the first deceleration stage for separating neutral particles from the ion beam, a second beam transport device for transporting the ion beam through the beam filter at the second transport energy, a second deceleration stage positioned downstream of the beam filter for decelerating the ion beam from the second transport energy to a final energy, and a target site for supporting a target for ion implantation. The ion beam is delivered to the target site at the final energy.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: February 14, 2006
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Charles M. McKenna, Nicholas R. White, Douglas A. Brown, Edward Bell, Svetlana Radovanov
  • Patent number: 6653642
    Abstract: Methods and apparatus are provided for efficiently operating an ion implanter which includes a charged particle accelerator in a high energy mode and in a low energy mode. The charged particle accelerator includes a high voltage power supply, an accelerator column coupled to the high voltage power supply and a switching assembly. The accelerator column includes a plurality of accelerator electrodes. The high voltage power supply is disabled from energizing the accelerator column in the low energy mode. The switching assembly includes switching elements for electrically connecting the accelerator electrodes to a reference potential in the low energy mode and for electrically isolating the accelerator electrodes from the reference potential in the high energy mode. The switching assembly prevents positive potentials on the accelerator electrodes and thus minimizes space charge expansion of the beam when transporting positive ion beams in the low energy mode.
    Type: Grant
    Filed: February 8, 2001
    Date of Patent: November 25, 2003
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Bjorn O. Pedersen, Peter E. Maciejowski, William G. Goodenough, Paul J. Murphy, Charles M. McKenna
  • Publication number: 20010040220
    Abstract: Methods and apparatus are provided for efficiently operating an ion implanter which includes a charged particle accelerator in a high energy mode and in a low energy mode. The charged particle accelerator includes a high voltage power supply, an accelerator column coupled to the high voltage power supply and a switching assembly. The accelerator column includes a plurality of accelerator electrodes. The high voltage power supply is disabled from energizing the accelerator column in the low energy mode. The switching assembly includes switching elements for electrically connecting the accelerator electrodes to a reference potential in the low energy mode and for electrically isolating the accelerator electrodes from the reference potential in the high energy mode. The switching assembly prevents positive potentials on the accelerator electrodes and thus minimizes space charge expansion of the beam when transporting positive ion beams in the low energy mode.
    Type: Application
    Filed: February 8, 2001
    Publication date: November 15, 2001
    Applicant: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Bjorn O. Pedersen, Peter E. Maciejowski, William G. Goodenough, Paul J. Murphy, Charles M. McKenna
  • Patent number: 5136171
    Abstract: Methods and apparatus for neutralization of a workpiece such as a semiconductor wafer in a system wherein a beam of positive ions is applied to the workpiece. The apparatus includes an electron source for generating an electron beam and a magnetic assembly for generating a magnetic field for guiding the electron beam to the workpiece. The electron beam path preferably includes a first section between the electron source and the ion beam and a second section which is coincident with the ion beam. The magnetic assembly generates an axial component of magnetic field along the electron beam path. The magnetic assembly also generates a transverse component of the magnetic field in an elbow region between the first and second sections of the electron beam path. The electron source preferably includes a large area lanthanum hexaboride cathode and an extraction grid positioned in close proximity to the cathode.
    Type: Grant
    Filed: January 25, 1991
    Date of Patent: August 4, 1992
    Assignee: Varian Associates, Inc.
    Inventors: Ka-Ngo Leung, Wulf B. Kunkel, Malcom D. Williams, Charles M. McKenna
  • Patent number: 4757208
    Abstract: A masked ion beam lithography (MIBL) system and method is disclosed which is considerably more compact and economical than prior ion implantation devices. An H.sup.+ ion beam is extracted from a source in the form of an angularly expanding beam, and is transmitted through two lenses that sequentially accelerate the ions to energies in the range of 200-300 keV. The first lens focuses the beam so that it emerges from a crossover point with an amplified angular divergence at least three times the divergence of the initial beam, thereby considerably reducing the necessary column length. The second lens collimates the beam so that it can be directed onto a mask to expose resist on an underlying semiconductor substrate. A series of extraction electrodes are used to provide an initial point source beam with a desired angular expansion, and a specially designed sector magnet is positioned between the extraction mechanism and the first lens to remove particles heavier than H.sup.+ from the beam.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: July 12, 1988
    Assignee: Hughes Aircraft Company
    Inventors: Charles M. McKenna, James E. Wood, John L. Bartelt, Ross D. Olney, J. William Ward, Charles W. Slayman
  • Patent number: 4752692
    Abstract: U-shaped billet (52) has a slot (54) cut therein for receipt of a slip of insulator material (56). This body is machined on its front end (64) to produce a narrow bridge (66) of controlled cross-sectional area. Emitter needle (78) is positioned in a bore through the bridge to be heated by current through the bridge. The ion emitter body is rigid and strong to hold the emitter needle in the proper location.
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: June 21, 1988
    Assignee: Hughes Aircraft Company
    Inventors: Jerg B. Jergenson, Charles M. McKenna
  • Patent number: 4687940
    Abstract: An ion beam microfabrication system is described which is capable of operating in either a flooded beam mode, in which a relatively high current beam is used to yield a rapid throughput, or in a low current, high resolution focused ion beam mode. With a focused beam a small, relatively low current ion spot is deflected in a predetermined pattern over a portion of the wafer to produce more detailed patterning that is not achievable in the flooded beam mode. A lens is added to the beam column to modify the beam collimation between the focused and flooded modes, and switching between modes is accomplished by simply actuating or de-actuating the lens. The beam is formed with a larger acceptance angle and total current in the flooded than the focused mode.
    Type: Grant
    Filed: March 20, 1986
    Date of Patent: August 18, 1987
    Assignee: Hughes Aircraft Company
    Inventors: J. William Ward, John L. Bartelt, Robert L. Seliger, Charles M. McKenna
  • Patent number: 4686414
    Abstract: A process for enhancing the wettability of evaporation elements, such as substrates and metal reservoirs used in liquid metal ion sources, and the elements so produced wherein a coating material is wettably coated onto the evaporation element at a coating temperature greater than the ion source operating temperature. The coated element is cooled to the operating temperature, and then contacted with the molten ion source alloy. The coating material is selected to wet the substrate or reservoir at the coating temperature, but to be itself wet by the ion source alloy at the ion source operating temperature. The preferred coating metal is gold, which is first applied by electrodeposition onto the evaporation element, and the evaporation element and coating are heated to a coating temperature of about 800.degree. C. to complete the coating step. The coated evaporation element is cooled to the source operating temperature of 200.degree. C.-300.degree. C.
    Type: Grant
    Filed: November 20, 1984
    Date of Patent: August 11, 1987
    Assignee: Hughes Aircraft Company
    Inventors: Charles M. McKenna, Irwin R. Sharapata, William M. Clark, Jr.
  • Patent number: 4629931
    Abstract: A liquid metal ion source alloy for high vapor pressure metalloids, wherein the alloy composition is chosen to have a low melting point so that the vapor pressure of the volatile constituents is low, even in the liquid state. Specifically, the ion source alloy is an alloy selected from the group of (Pb.sub.0.7-1.0 Au.sub.0.3-0).sub.0.7-0.99 (As+Sb).sub.0.3-0.01 and Pb.sub.0.20-0.30 Au.sub.0.45-0.55 (As+Sb).sub.0.20-0.30. The melting points of these alloys are about 200.degree. C.-300.degree. C., and the alloys may be maintained molten in contact with the emission elements for long periods of time without significant loss of the volatile species or reactivity with typical substrate materials used for emission elements.
    Type: Grant
    Filed: November 20, 1984
    Date of Patent: December 16, 1986
    Assignee: Hughes Aircraft Company
    Inventors: William M. Clark, Jr., Charles M. McKenna, William L. Johnson
  • Patent number: 4556798
    Abstract: Two lens focused ion beam column (10) has an accelerating lens (20) which carries a potential to focus an image of the liquid metal ion source (14) on the mass analyzer slit (26) with a magnification of about unity. Munro lens (36) accelerates the beam of selected ion species and demagnifies the image through a long working distance to provide an ion writing spot of less than about 1000 .ANG. size.
    Type: Grant
    Filed: July 12, 1983
    Date of Patent: December 3, 1985
    Assignee: Hughes Aircraft Company
    Inventors: Charles M. McKenna, William M. Clark, Jr., Robert L. Seliger
  • Patent number: 4383177
    Abstract: A plurality of magnetic pole pieces are arranged around the external wall of a high temperature plasma confining structure. The pole pieces are positioned between permanent magnets spaced from one another and the confining structure by distances calculated to produce a minimum field toward the center of the structure with an effective containing field around the periphery of the structure. The magnets and the pole pieces are cooled. An odd number of poles are employed such that the missing pole appears as a virtual pole at the extraction slit used for forming an ion beam for ion implantation. The resulting small package multipole plasma containment functions to provide higher beam current, longer source lifetime, higher voltage stability and reduces maintenance and cleaning operations, with the permanent magnets protected from high temperature and corrosive gases.
    Type: Grant
    Filed: December 24, 1980
    Date of Patent: May 10, 1983
    Assignee: International Business Machines Corporation
    Inventors: John H. Keller, Charles M. McKenna
  • Patent number: 4183780
    Abstract: A method and apparatus for modifying a surface, by either plasma etching the surface or plasma depositing a material thereon, by using vacuum ultraviolet radiation to control the modification of the surface.
    Type: Grant
    Filed: August 21, 1978
    Date of Patent: January 15, 1980
    Assignee: International Business Machines Corporation
    Inventors: Charles M. McKenna, H. Keith Willcox
  • Patent number: 4179312
    Abstract: A method and apparatus for depositing a monocrystalline epitaxial layer of semiconductor material, e.g., silicon containing selected conductivity-determining impurities, on a semiconductor substrate comprising directing a beam of ions of said semiconductor material at the surface of the semiconductor substrate at an energy level below 0.5 Kev., and simultaneously directing a beam of the conductivity-determining impurity ions at at least a portion of the substrate surface whereby a layer of semiconductor material containing said conductivity-determining impurities is formed on said surface, and heating said layer to a temperature of at least 550.degree. C. to render said layer monocrystalline. The beams of semiconductor ions and of conductivity-determining impurity ions are preferably maintained at a high current density of at least 1 ma/cm.sup.2 at the surface of said semiconductor substrate even with a preferable relatively broad beam having diameters of up to 15 cm.
    Type: Grant
    Filed: November 20, 1978
    Date of Patent: December 18, 1979
    Assignee: International Business Machines Corporation
    Inventors: John H. Keller, Charles M. McKenna, James R. Winnard
  • Patent number: 4158589
    Abstract: Process and apparatus for use in extracting negative ions from a plasma which is particularly useful in reactive ion etching of metals, silicon and oxides and nitrides of silicon in the manufacture of semiconductor devices. A magnetic field is employed in the apparatus and, herein, is created by a novel grid, through which negative ions pass to a surface, such as one to be etched, while free electrons are prevented from passing through the grid and out of the plasma. The novel process utilizes negative ions which have a large fraction in the atomic state.
    Type: Grant
    Filed: December 30, 1977
    Date of Patent: June 19, 1979
    Assignee: International Business Machines Corporation
    Inventors: John H. Keller, Charles M. McKenna
  • Patent number: 4151420
    Abstract: An apparatus for depositing a monocrystalline epitaxial layer of semiconductor material, e.g., silicon containing selected conductivity-determining impurities, on a semiconductor substrate comprising directing a beam of ions of said semiconductor material at the surface of the semiconductor substrate at an energy level below 0.5 Kev., and simultaneously directing a beam of the conductivity-determining impurity ions at at least a portion of the substrate surface whereby a layer of semiconductor material containing said conductivity-determining impurities is formed on said surface, and heating said layer to a temperature of at least 550.degree. C. to render said layer monocrystalline. The beams of semiconductor ions and of conductivity-determining impurity ions are preferably maintained at a high current density of at least 1 ma/cm.sup.2 at the surface of said semiconductor substrate even with a preferable relatively broad beam having diameters of up to 15 cm.
    Type: Grant
    Filed: December 8, 1977
    Date of Patent: April 24, 1979
    Assignee: International Business Machines Corporation
    Inventors: John H. Keller, Charles M. McKenna, James R. Winnard
  • Patent number: 4149084
    Abstract: In an apparatus for bombarding a target with a beam of ions, an expedient is provided for maintaining the beam line and target under vacuum of 2.times.10.sup.-4 Torr. or lower pressures. The apparatus includes a mass separator, e.g., analyzing magnet adapted to provide selected ions which are to be formed into the desired beam with a trajectory along a selected axis: the target is positioned along this selected axis; the apparatus further includes: a housing extending from the mass separator to the target to enclose the axis and target within a chamber, beam defining means within said chamber traversing said axis and impeding the flow of gas through said chamber, said defining means having a beam defining opening therein at said axis to permit the passage of a selected portion of the beam toward the target, and vacuum drawing means connected to said chamber through an opening in said housing crossing said beam defining means whereby said drawing means removes gas from both sides of said beam defining means.
    Type: Grant
    Filed: November 1, 1977
    Date of Patent: April 10, 1979
    Assignee: International Business Machines Corporation
    Inventors: Herbert L. Arndt, deceased, by Margaret L. Arndt, administratrix, John H. Keller, Charles M. McKenna, James R. Winnard
  • Patent number: 4135097
    Abstract: In an ion beam apparatus a structure for controlling the surface potential of the target comprising an electron source adjacent to the beam for providing electrons to the beam and means between the target and source for inhibiting rectilinear radiations, i.e., electron and other particle and photon radiations between said source and said target. This prevents heating of the target by the electron source and cross-contamination between the source and the target.
    Type: Grant
    Filed: May 5, 1977
    Date of Patent: January 16, 1979
    Assignee: International Business Machines Corporation
    Inventors: John L. Forneris, William W. Hicks, John H. Keller, Charles M. McKenna, James A. Seirmarco
  • Patent number: 4118630
    Abstract: In an ion beam apparatus a structure for controlling the surface potential of the target comprising an electron source adjacent to the beam for providing electrons to the beam and means between the target and source for inhibiting rectilinear radiations, i.e., electron and other particle and photon radiations between said source and said target. This prevents heating of the target by the electron source and cross-contamination between the source and the target. The apparatus further includes means for maintaining said shield means at a lower temperature than said target.
    Type: Grant
    Filed: May 5, 1977
    Date of Patent: October 3, 1978
    Assignee: International Business Machines Corporation
    Inventors: Charles M. McKenna, Wolfgang F. Mueller