Patents Represented by Attorney Peter J. Sgarbossa
  • Patent number: 5024747
    Abstract: Semiconductor wafers having patterns of steps and grooves defining microcircuit elements thereon are coated with metallic film by supporting the wafers individually adjacent a respective ring-shaped sputtering source in stationary relationship thereto. To effectuate such individual wafer processing on a continuous basis and preserve the evacuated argon environment, a vacuum chamber sputter coating apparatus is provided which has a number of work stations therein, at least one of which includes said ring-shaped sputtering source. Also included is a load lock; and an intermittently rotating vertical plate-like wafer carrier means therewithin positioned closely adjacent the chamber entrance, and carrying wafers in turn from the load lock to the work stations. The carrier includes apertures each accepting a wafer therewithin in an upright position, with the wafers edgewise resiliently supported by clip means, without the use of any externally-originating supports such as platens.
    Type: Grant
    Filed: June 1, 1988
    Date of Patent: June 18, 1991
    Assignee: Varian Associates, Inc.
    Inventors: Frederick T. Turner, Martin A. Hutchinson, R. H. Shaw, Lawrence T. Lamont, Jr.
  • Patent number: 5025193
    Abstract: The collector in a linear-beam electron tube is insulated from its heat sink so that it can be operated at a depressed potential. The insulation comprises two bands of dielectric sequentially in contact between the collector and heat sink. The intervening space is sealed off and preferably filled with a dielectric fluid to improve heat transfer and inhibit voltage breakdown. Gaps in one band are preferably aligned with solid parts of the other to reduce electric leakage.
    Type: Grant
    Filed: June 19, 1990
    Date of Patent: June 18, 1991
    Assignee: Varian Associates, Inc.
    Inventor: Bertram G. James
  • Patent number: 5023768
    Abstract: A high voltage, high power DC power supply includes a single turn primary winding driven through a resonating capacitor by an AC source having a frequency in excess of about 100 kHz. The primary winding includes a pair of concentric cylindrical metal walls having opposite ends electrically connected to each other. A volume between the walls includes plural secondary winding assemblies, having different axial positions along the walls. Each of the assemblies includes an annular magnetic core surrounding the interior wall, a winding on the core and a voltage doubler rectifier. DC voltages developed across each secondary winding assembly by the rectifier are added together to provide the high voltage, high power output. The power supply energizes an X-ray tube having a grounded anode and a cathode at a DC voltage of approximately -150 kV, with a power requirement of between 15 and 60 kW.
    Type: Grant
    Filed: December 13, 1989
    Date of Patent: June 11, 1991
    Assignee: Varian Associates, Inc.
    Inventor: John C. Collier
  • Patent number: 5015914
    Abstract: In a gyrotron cavity resonator, generated energy is extracted into a symmetric set of fundamental-mode waveguides by ports disposed to couple energy in phase from the operating electromagnetic mode but in anti-phase with respect to an unwanted mode of lower cutoff frequency than the operating mode, thereby neutralizing coupling to the unwanted mode. A second set of interspersed ports may be disposed to load degenerate, orthogonal modes.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: May 14, 1991
    Assignee: Varian Associates, Inc.
    Inventors: Robert L. Ives, Howard R. Jory, Albert D. LaRue
  • Patent number: 5002010
    Abstract: Pre- and post-processing of a semiconductor wafer within a main vacuum chamber is accomplished by a wafer holder disposed within a clam shell-like device. The clam shell device includes a first member disposed above the wafer holder and a second member disposed below the wafer holder in a facing relationship to the first member. The first member and the second member each have a respective mating surface. The first member and the second member are movable between a closed position wherein the mating surface of each of the first member and second member hermetically engage each other in an open position. The clam shell device forms an interior chamber when in its closed position. Gases are evacuated from the interior chamber, exteriorally of the main chamber, when the clam shell device is in in a closed position to avoid contamination of the vacuum environment.
    Type: Grant
    Filed: October 18, 1989
    Date of Patent: March 26, 1991
    Assignee: Varian Associates, Inc.
    Inventor: Richard S. Weinberg
  • Patent number: 4997606
    Abstract: Thermal transfer between a semiconductor wafer and a platen during vacuum processing is provided through a soft, thermally-conductive polymer layer having a thin, hard surface film. The soft polymer layer, which is preferably silicon rubber containing thermally-conductive particles, conforms to surface irregularities on the wafer and has low thermal resistance. The surface film is preferably silicon dioxide in the form of a multiplicity of flat plates integrally formed on the silicone rubber. Adherence of the wafer and of foreign matter to the polymer layer is prevented by the surface film. In addition, the underlying polymer layer is protected by the surface film. A high purity polymer layer is fabricated by evacuating the mold cavity and the resin container prior to injection of resin. The mold for the polymer layer utilizes a hard, smooth mold release surface and a resilient gasket between the platen and the mold release surface.
    Type: Grant
    Filed: October 10, 1989
    Date of Patent: March 5, 1991
    Assignee: Varian Associates, Inc.
    Inventors: Eric L. Mears, Keith D. Pierce
  • Patent number: 4994709
    Abstract: A very fine-mesh, non-emissive shadow grid is formed on the smooth emissive surface 16 of a thermionic cathode 12 by deposition from a vapor a continuous layer 22 of non-emissive conductive material. Between the elements 24 of the grid the non-emissive material is removed by bombardment through an apertured mask to restore emissivity between the elevated grid elements 24.
    Type: Grant
    Filed: March 22, 1989
    Date of Patent: February 19, 1991
    Assignee: Varian Associates, Inc.
    Inventors: Michael C. Green, George V. Miram
  • Patent number: 4988919
    Abstract: A compact, small diameter, standing-wave linear accelerator structure suitable for industrial and medical applications is disclosed. The novel structure utilizes a new type of coupling cavity for Pi/2 mode, standing-wave operation. The coupling cavity fits into the webs between the accelerating cavities substantially within the diameter of the acclerating cavities. This is made possible by keeping the center section of the cavity thin to concentrate the electric field vector at the center of a section of the cavity and by enlarging the ends of a section of the coupling cavity to accommodate the magnetic field vector. This structure offers a significant reduction in overall diameter over the side-coupled, annular ring, and existing coaxial coupled structures, while maintaining a high shunt impedance and large nearest neighbor coupling (high group velocity). A prototype 4 MeV, 36 cm long, S-band accelerator incorporating the new structure has been built and tested.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: January 29, 1991
    Assignee: Varian Associates, Inc.
    Inventors: Eiji Tanabe, Matthew Bayer, Mark E. Trail
  • Patent number: 4981408
    Abstract: A dual track substrate handling and processing system includes an entrance load lock station, an exit load lock station and a plurality of substrate processing stations, all positioned above a transfer vacuum chamber. The load lock station and each processing station are configured to hold two vertically oriented workpieces. A transport system conveys workpieces two at a time from parallel input cassettes to the entrance load lock station. The transport system includes a transport assembly that simultaneously advances two workpieces from each station to the next station; thus workpieces are processed two at a time in the same environment in each processing station and system throughput is correspondingly increased.
    Type: Grant
    Filed: December 18, 1989
    Date of Patent: January 1, 1991
    Assignee: Varian Associates, Inc.
    Inventors: John L. Hughes, Thomas E. Shula, Carlos E. Rodriguez
  • Patent number: 4952814
    Abstract: A microwave electron accelerator has a very limited range over which pulse beam current can be adjusted without destabilizing the operation of the machine. Therefore, means must be devised to reduce current without seriously reducing energy, or producing unwanted x-rays. One means includes spreading the beam in a scattering foil and subsequently absorbing the outer portion with a blocking wall. In order to make the means adjustable the foil thickness, the size of a passing aperture in the blocking wall or the position of the blocking wall can be adjusted.
    Type: Grant
    Filed: June 14, 1989
    Date of Patent: August 28, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Calvin J. Huntzinger
  • Patent number: 4949011
    Abstract: In a multicavity klystron amplifier, the drift-tube bore is larger (46) in proportion to the beam size (10) in the non-interacting space between gaps (28) than its size (22) at the gaps (28). This decreases the spacecharge wavelength so that the overall physical length of the klystron is shortened.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: August 14, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Joseph K. Mann
  • Patent number: 4945464
    Abstract: A DC power supply for a traveling wave tube having cathode, collector and helix electrodes responds to a DC power source and a high frequency switching source. A switch controlled by the switching source is opened and closed at a fixed frequency and variable duty cycle determined by the helix-cathode voltage. A flyback choke is connected to the switch and DC power supply so current flows between the power source via the choke to the switch and a series resonant circuit while the switch is closed. First and second capacitors in separate branch circuits of the resonant circuit are respectively connected to first and second AC to DC converter and voltage multiplier stacks; each multiplier in the stacks includes a pair of branches with oppositely poled plural signal switching diodes and a capacitor. The cathode and helix are respectively connected to output terminals of the first and second stacks, while the collector is connected to a terminal between the first and second stacks.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: July 31, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Bradley R. Gunn
  • Patent number: 4917556
    Abstract: A modular wafer processing machine is provided which is based on interconnected handling units having wafer handling arms. Each unit can pass a wafer to another unit in the same vacuum environment to a processing module.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: April 17, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Lawrence R. Stark, Frederick Turner
  • Patent number: 4909314
    Abstract: In a vacuum chamber wafer treating apparatus, a wafer is heated or cooled by introducing a gas at a pressure of approximately 100 to 1000 microns in a region between the wafer and a heating element or heat sink. The gas conducts thermal energy between the wafer and heating element or heat sink.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: March 20, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Lawrence T. Lamont, Jr.
  • Patent number: 4906953
    Abstract: A broadband interconnection between a microstrip and a coplanar waveguide is provided without use of via holes by using anisotropic etching to form a sloped surface between connection points. The sloped surface is then metallized to provide the interconnection.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: March 6, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Chia-Geng Li, Steve G. Bandy, Majid Riaziat
  • Patent number: 4868843
    Abstract: In a radiation therapy machine it is desirable to produce irregular radiation field shapes in order to shield critical organs not invaded by the tumor. A system is provided using a multileaf collimator formed of a multiplicity of heavy metal bar leaves driven relative to a pair of frames which are driven relative to jaws of a rectangular field collimator. A multiplicity of compensators, one attached to each leaf on one of the pair of frames is used to adjust the local intensity of the radiation within the field. The x-ray beam is limited to a fan with the jaws, the ends and selected parts of the fan are blocked by the multileaf collimator, and the intensity within various portions of the remaining beam is adjusted with compensators. The field of the fan beam is dynamically controlled by these means while the patient table is moved perpendicular to the plane of the fan beam.
    Type: Grant
    Filed: July 10, 1987
    Date of Patent: September 19, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Craig S. Nunan
  • Patent number: 4866343
    Abstract: A slow-wave circuit for a TWT has periodic transverse plates extending across the axial by extending vacuum envelope. An opposed pair of apertures 24, 26 in each plate 20 couple adjacent cavities 28 between plates 20. Coupling apertures 24 in alternate plates 20 are rotated transverse to apertures 26 in the other plates to provide coupling only between adjacent cavities 28. Each plate 20 has transverse ridges 30 enclosing its axial beam aperture 22. The ridges 30 are orthogonal to the coupling apertures 24, 26 to increase beam coupling and decrease capacitance for wider bandwidth and higher impedance.
    Type: Grant
    Filed: October 20, 1988
    Date of Patent: September 12, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Bertram G. James
  • Patent number: 4866344
    Abstract: A power supply for helix and collector electrodes of a traveling wave tube is driven by an AC power source having a frequency of at least 500 KHz. The helix supply includes plural, stacked voltage double AC to DC modules responsive to the 500 KHz source. The collector supply includes plural AC to DC modules, each having a diode full wave rectifier bridge, connected in stacked relation. Each of the modules includes a transformer with a ferrite, toroidal core dimensioned so that it is not driven into saturation by the 500 KHz source. Each module also includes inexpensive, signal switching diodes having a recovery time of approximately 4 nanoseconds. The ratio of the collector to helix DC voltages is maintained constant by threading a common lead through the apertures of the toroidal cores of the helix and collector modules. A separate common lead threaded through the apertures of the toroidal cores in the collector modules is connected directly to the 500 KHz power source.
    Type: Grant
    Filed: August 29, 1988
    Date of Patent: September 12, 1989
    Assignee: Varian Associates, Inc.
    Inventors: Randall I. Ross, Bradley Gunn
  • Patent number: 4851788
    Abstract: A gyrotron interaction resonator 29 operating in a TE.sub.n1 cavity mode has an array of longitudinal slots 32 in the conductive wall 30. The slots 32 are spaced to couple to the unwanted TE.sub.n1 modes and to other modes of differing n and not to the desired mode. Wave-absorptive material 34 spaced from the inner cavity wall 28 and coupled to slots 32 absorbs the unwanted modes.
    Type: Grant
    Filed: June 1, 1988
    Date of Patent: July 25, 1989
    Assignee: Varian Associates, Inc.
    Inventors: Robert L. Ives, Howard R. Jory, Joseph Feinstein
  • Patent number: 4821165
    Abstract: A DC power supply for a traveling wave tube having cathode, collector and helix electrodes responds to a DC power source and a high frequency switching source. A switch controlled by the switching source is opened and closed at a fixed frequency and variable duty cycle determined by the helix-cathode voltage. A flyback choke is connected to the switch and DC power supply so current flows between the power source via the choke to the switch and a series resonant circuit while the switch is closed. First and second capacitors in separate branch circuits of the resonant circuit are respectively connected to first and second AC to DC converter and voltage multiplier stacks; each multiplier in the stacks includes a pair of branches with oppositely poled plural signal switching diodes and a capacitor. The cathode and helix are respectively connected to output terminals of the first and second stacks, while the collector is connected to a terminal between the first and second stacks.
    Type: Grant
    Filed: June 15, 1987
    Date of Patent: April 11, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Bradley R. Gunn