Abstract: An electron capture detector for use with a capillary column is provided with a sample inlet comprising a tubular anode through which sample molecules and a make-up gas are introduced into the detector cell. The tubular anode has side ports for producing a plug-like flow inside the cell. The inner surface of the anode is protected by an insulating tube so that the capillary column can be extended to a point beyond the side ports without the fear of its electrical contact with the anode. This allows the sample molecules to flow nearly entirely in the center section of the cell. The peripheral regions of the cell where a radioactive foil is disposed is swept nearly entirely by the make-up gas entering the cell through the side ports. This has the effects of reducing sample dilution by the make-up gas and sample loss due to contact with the detector walls.
Abstract: An elevator structure is actuated to remove wafers individually out of a storage cassette to an elevated delivery position. The elevator is a lift blade with an arcuate upper end shaped to match the curvature of the wafers, and a groove within this end adapted to match the thickness of a wafer and retain a wafer edgewise. A wafer-holding chuck on a chuck assembly is adapted to receive a wafer from the elevator when the elevator is in the elevated delivery position. The chuck assembly is movable from the delivery position to a remote position where the chuck presents the wafer to a support member. The support member is provided with an aperture and a plurality of deformable wafer-holding clips spaced around the aperture. The chuck assembly includes a pneumatic cylinder capable of contacting a portion of each clip to urge same to an open position. The invention includes an arrangement in which the chuck is mounted on a chuck assembly in the form of a door for sealing an opening in a process chamber.
Type:
Grant
Filed:
August 15, 1983
Date of Patent:
March 3, 1987
Assignee:
Varian Associates, Inc.
Inventors:
George L. Coad, Martin A. Hutchinson, R. Howard Shaw
Abstract: A matched lossless reciprocal five-port junction can be constructed as a tapered five-fold symmetric star. The dimensions of the leads are tapered in toward the center, such that the cutoff frequency is the upper band frequency divided by 1.66.
Abstract: A thermocouple pressure gauging system for measuring partial vacuum is provided which uses AC current to heat the thermocouple to constant temperature. A signal proportional to pressure is derived from the AC current needed to heat to constant temperature.
Abstract: Apparatus for programmably orienting a semiconductor wafer in an ion implantation system so as to limit channeling and to control the depth of penetration of impinging ions. The apparatus is associated with a processing chamber door and includes a rotatable vacuum chuck for engaging the wafer and a motor for rotating the vacuum chuck and the wafer through a preselected angular displacement. The apparatus further includes a programmable control assembly operative to deenergize the motor upon sensing rotation of the vacuum chuck through the preselected angular displacement. The wafer orientation apparatus is typically utilized in a system for the vertical transfer of wafers between a cassette and a processing chamber.
Abstract: A structure for use in an X-ray membrane (pellicle) mask is provided in which anodic bonding of layers is employed. Anodic bonding as used here provides a permanent bond between the layers, has zero thickness and provides substantial improvements in the obtained flatness of the mask by eliminating conventional glue for attachment. By applying a voltage between a layer, such as silicon, and a glass plate, and simultaneously heating both elements a permanent bond is established which is extremely flat thus providing minimum misalignment of the mask during subsequent X-ray lithography fabrication.
Type:
Grant
Filed:
February 16, 1984
Date of Patent:
December 30, 1986
Assignee:
Varian Associates, Inc.
Inventors:
Marcos Karnezos, Howard H. Nakanos, Armand P. Neukermans
Abstract: In an apparatus for etching a large semiconductor wafer the etch rate and uniformity of etching at the edges is improved by using an array of magnets behind the collector plate to form a double ring of plasma and using a grounded shield ring with perforations to pass gases. The shield ring extends both above and below the surface of the wafer being etched.
Abstract: A linear accelerator includes cascaded standing wave main cavities with approximately the same resonant frequency and plural side cavities. A charged particle beam travels longitudinally through the main cavities. An electromagnetic wave excites the cavities with a frequency that is approximately the same as the resonant frequency of the main cavities. There is normally a fixed electromagnetic energy phase shift in adjacent main cavities. The resonant frequency of at least one side cavity is adjusted so it differs from the electromagnetic wave frequency. The detuned side cavity resonant frequency causes: (a) a change in the normal fixed phase shift of the main cavities adjacent the one side cavity and (b) a decrease in electric field strength in cavities electromagnetically downstream of the one side cavity relative to the electric field strength in cavities electromagnetically upstream of the one side cavity.
Abstract: An improved magnetron sputter source particularly suitable for magnetic materials is provided in the forming of an unfolded Penning discharge source. The two cathodes are in the form of an inner cathode roughly coplanar with an outer cathode ring. An anode radially between the cathodes is raised above the cathode surfaces so as to block line of sight from the inner cathode surface to the outer. A magnetic flux vector is imposed which passed from one cathode surface to the other. Raising the anode surface about one-fourth inch above the cathode surfaces allows raising the applied voltage so that a source of 5 kilowatts or greater is possible. Raising the anode also spreads the distribution of discharge more uniformly over the target surface and permits low pressure operation thereby facilitating good adhesion and uniform coverage of the substrate.
Abstract: A first target for a magnetron sputter device has a planar annular emitting surface bounded by an inner radius R1 and an outer radius R2. A second target has a sloped emitting surface defined by a side wall of a frustum of a cone. The second target is limited by an inner radius R3 and outer radius R4. R3 is greater than R2. Each target element has pins in diametrically opposite holes to assist in holding the target elements in situ in bayonet slots in the sputter device. The targets are fit closely in cooling rings so that as the targets heat during operation, thermal expansion of the targets assists thermal conduction into the cooling rings. A coil is formed behind the workpiece to act as a mirror to the plasma. The field of the coil moves the plasma away from the workpiece which permits putting high power R.F. bias on the workpiece. The R.F. bias in combination with gas heating the wafer from behind aids in sputtering a coating of superior conformality.
Abstract: Apparatus for fabricating a compensating filter for use in radiation therapy includes a stylus for tracing the profile of a surface portion of a patient and a cutter for cutting a form. The stylus and cutter are positioned on first and second guides which are connected by a tie bar. A plurality of linkages translate movement of the stylus along its guide to the cutter along its guide. A mold is cut in the form which is filled with compensating material for forming the filter. The ratio of movement of the stylus to the cutter is established by the linkages in accordance with the ratio of radiation absorption of the compensating material to the radiation absorption of human tissue.
Abstract: An ultrasound hyperthermia applicator comprises a plurality of transducers which can be operated in different grouping modes so that the applicator is effectively provided with a variable number of elements having variable effective diameters transmitting coherent beams. The individually coherent beams from these elements are individually focused for incoherent superposition in the target volume according to a spiral or multi-spiral focusing scheme. Such an applicator is capable of uniformly heating without scanning a limited part of human body with volume greater than the inherent focal size of the individual transmitter element.
Abstract: A vacuum pick suitable for removing semiconductor wafers from and replacing wafers in a cassette holder. The vacuum pick includes a thin profile housing having a wafer support surface with a cavity therein, a resilient, flexible member covering a portion of the cavity to form an enclosure, and a rigid chuck mounted on the flexible member so as to permit movement of the chuck relative to the housing. The chuck includes a wafer-receiving surface connected through a passage to the enclosure. When a vacuum is applied to the enclosure, the wafer and the chuck are retracted against the housing and held firmly in place. The chuck tilts relative to the housing when it contacts a tilted wafer, thereby insuring reliable attachment to the wafer.
Abstract: In an electron beam tube such as a gyrotron, electron dissipation on the collector wall is often quite non-uniform due to radial concentrations of the electrons. The dissipation is made more uniform by pseudo-random scrambling of trajectories by transverse magnetic fields which are non-uniform in transverse and axial dimensions.
Abstract: A sample modulator cell for chromatographic analysis uses a diverting valve to send a carrier gas into a duct in a generally closed circular form periodically alternately through two separate ports. A sample inlet port opens between the carrier ports so that a sample-containing gas periodically alternately flows to an exit port through two channels A and B of different lengths in the duct. A phase-shift of 180.degree. is introduced between the channels so that all of the sample introduced into the modulator will be used for the analysis, thus increasing the peak response.
Abstract: An apparatus for automatically processing the wire ends of cores includes a forming die for bending the axially projecting wire ends back to project parallel to one another generally away from the core. Cores are received in a receiving station aligned with the forming die and orientated so that the wire ends are spaced as far as possible from the die. When the wire ends are sensed to be in the correct orientation, an actuator is operated to push the core through the forming die. The core with its wire ends bent back is then preferably stepped through a series of processing stations to trim and tin the wire ends and then ejected from the machine. A series of cores can be stepped continuously one after the other through the machine.
Abstract: An X-ray lithography apparatus permits the successive exposure of each of four quadrants of a semiconductor wafer through a single mask. The mask overlays one quadrant of the wafer at a time and the wafer is rotated through 90 degrees after exposure of a quadrant to allow exposure of succeeding wafer quadrants; each wafer quadrant is independently aligned to the mask prior to exposure. In an alternative preferred embodiment, a rotatable diaphragm is used to select a single mask quadrant from a mask which overlays the entire surface of the semiconductor wafer. Both the wafer and the diaphragm may be rotated to allow various exposure combinations of mask and wafer quadrants.
Type:
Grant
Filed:
January 24, 1984
Date of Patent:
September 23, 1986
Assignee:
Varian Associates, Inc.
Inventors:
Graham J. Siddall, Steven G. Eaton, James B. Kruger, Garrett A. Garrettson, Armand P. Neukermans
Abstract: A tube for amplifying high-frequency multi-kilowatt, amplitude-modulated signals utilizes a linear beam of electrons which is density-modulated by a permeable control grid spaced close to a thermionic cathode. The beam is focused through a drift tube having two axially spaced gaps, each coupled to a resonant circuit such as a hollow cavity. The first circuit is tuned to a resonant frequency higher than the signal frequency to produce velocity-modulation bunching of the beam electrons in phase with the density-modulation from the grid. The second circuit is tuned to the signal frequency and its energy is coupled out to an external load. The grid modulation is Class B or Class C so there is no current between the electron bunches. The floating bunching circuit can thus, by velocity modulation, produce very dense bunches to excite the output circuit, providing very high conversion efficiency.
Abstract: In a crossed-field amplifier tube, an input section of slow-wave circuit is part of the cathode electrode. An output section of slow-wave circuit is part of the anode electrode. The anode circuit is axially displaced from the cathode circuit in the direction of drift of the electron stream so that a non-propagating section of the anode faces at least a part of the propagating cathode circuit.
Abstract: A Freeman type electron bombardment ion source includes dual filament electrodes positioned in an arc chamber having a slit for extraction of an ion beam. The filament electrodes are symmetrically positioned with respect to the extraction slit. The filament electrode currents are equal in magnitude and oppositely directed. As a result, lateral magnetic fields in the region of the extraction slit are substantially eliminated.