Photoionization Type Patents (Class 250/423P)
  • Patent number: 6140656
    Abstract: An ion generator vessel can be filled up with raw material gas containing a specific gas component. The ion generator vessel can be irradiated with a laser beam from a laser oscillator. Due to the beam which is applied into the ion generator vessel, only the specific gas component is selectively excited by multi-photon absorption, to generate ions. Thus, a semiconductor substrate can be inhibited from damage in ion implantation, and processability such as the throughput etc. can be improved.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: October 31, 2000
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Atsuhiro Fujii
  • Patent number: 6137110
    Abstract: A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: October 24, 2000
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Michael J. Pellin, Keith R. Lykke, Thorsten B. Lill
  • Patent number: 6111251
    Abstract: Matrix assisted laser desorption/ionization is performed in a manner to thermalize large analyte ions in a plume of desorbed material for spectroscopic analysis. The thermalized ions have a low or zero mean velocity and are presented at a well-defined instant in time, reducing artifacts and sharpening the spectral peaks. In one embodiment the light is delivered to a matrix or sample holder having a cover, baffle or compartment. The baffle or compartment impedes or contains a plume of desorbed material and the analyte undergoes collisions to lower its mean velocity and directionality. Thus "thermalized" the analyte ions are passed to a mass analysis instrument. In a preferred embodiment an optical fiber butts up against a thin transparent plate on which the specimen resides, with the matrix side in a vacuum acceleration chamber. A mechanical stage moves the specimen in both the x- and y-directions to select a point on the specimen which is to receive the radiation.
    Type: Grant
    Filed: September 19, 1997
    Date of Patent: August 29, 2000
    Assignee: Sequenom, Inc.
    Inventor: Franz Hillenkamp
  • Patent number: 6057543
    Abstract: A time-of-flight mass spectrometer for measuring the mass-to-charge ratio of a sample molecule is described. The spectrometer provides independent control of the electric field experienced by the sample before and during ion extraction. Methods of mass spectrometry utilizing the principles of this invention reduce matrix background, induce fast fragmentation, and control the transfer of energy prior to ion extraction.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: May 2, 2000
    Assignee: PerSeptive Biosystems, Inc.
    Inventors: Marvin L. Vestal, Peter Juhasz
  • Patent number: 6011267
    Abstract: A gas nozzle having an increased resistance to erosion from energetic plasma particles generated by laser plasma sources. By reducing the area of the plasma-facing portion of the nozzle below a critical dimension and fabricating the nozzle from a material that has a high EUV transmission as well as a low sputtering coefficient such as Be, C, or Si, it has been shown that a significant reduction in reflectance loss of nearby optical components can be achieved even after exposing the nozzle to at least 10.sup.7 Xe plasma pulses.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: January 4, 2000
    Assignee: EUV LLC
    Inventors: Glenn D. Kubiak, Luis J. Bernardez, II
  • Patent number: 6008496
    Abstract: A resonance ionization imaging device (RIID) and method for imaging objects using the RIID are provided, the RIID system including a RIID cell containing an ionizable vapor including monoisotopic atoms or molecules, the cell being positioned to intercept scattered radiation of a resonance wavelength .lambda..sub.1 from the object which is to be detected or imaged, a laser source disposed to illuminate the RIID cell with laser radiation having a wavelength .lambda..sub.2 or wavelengths .lambda..sub.2, .lambda..sub.3 selected to ionize atoms in the cell that are in an excited state by virtue of having absorbed the scattered resonance laser radiation, and a luminescent screen at the back surface of the RIID cell which presents an image of the number and position of charged particles present in the RIID cell as a result of the ionization of the excited state atoms.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: December 28, 1999
    Assignee: University of Florida
    Inventors: James D. Winefordner, Oleg I. Matveev, Benjamin W. Smith
  • Patent number: 6004770
    Abstract: A sample presentation device, with a surface-bound complex including at least one molecule which chemically modifies a biomolecule, is prepared and exposed to a biomolecule. The molecular weights of the chemically modified biomolecule is then determined by mass spectrometry.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: December 21, 1999
    Assignee: Arizona State University Board of Regents
    Inventor: Randall W. Nelson
  • Patent number: 5981955
    Abstract: A plasma chamber for use in isotope enrichment has a microwave feed to the ECRH microwave horns, which feed is led into the plasma chamber behind the sputter plate and perpendicular to the magnetic field for improved microwave waveguide routing and ease of microwave window handling and maintenance. Improved collector design includes a collector assembly placed behind the plasma source comprising a dump plate and flat and shield collector. A ring collector is provided outside the main plasma region in the case where two opposing magnetic mirrors are used and the resonant ions maintained between them. An improved collector assembly can also be provided by disposing the collector assembly in front of the plasma source region and having a double shield-and-slat collector for capturing high energy resonant ions or permitting passage of low energy ions therethrough. Sputter sources for nonconducting materials can be provided by using a thin surface coating applied to a metal backing.
    Type: Grant
    Filed: May 23, 1997
    Date of Patent: November 9, 1999
    Assignee: The Regents of the University of California
    Inventors: Alfred Y. Wong, Glenn B. Rosenthal
  • Patent number: 5977541
    Abstract: The present invention provides a laser ionization mass spectrometric apparatus comprising a sample introducing portion provided with a pulse valve which forms molecular jet, a pulsed laser beam oscillator, a vacuum ionization chamber or a corresponding portion thereto having a window capable of passing the laser beam radiated from the oscillator, and a mass spectrometer which analyzes the mass of molecules ionized by the laser beam, wherein said pulse laser oscillator has an ability of oscillating ultrashort pulsed laser beam having a peak output of 1 MW or more. The laser ionization mass spectrometric apparatus can use a turbo-molecular vacuum pump to evacuate the above vacuum ionization chamber and the above sample introducing portion can comprise two or more pinhole nozzles.
    Type: Grant
    Filed: August 18, 1998
    Date of Patent: November 2, 1999
    Assignee: NKK Corporation
    Inventors: Kunio Miyazawa, Totaro Imasaka, Hitoshi Miyamoto
  • Patent number: 5977540
    Abstract: The present invention provides methods and apparatus for analyzing the particulate contents of a sample such that a high proportion of the sample particles are analyzed without discrimination against high electronegativity and high ionization potential elements. In an exemplary embodiment, the invention comprises an apparatus for analyzing the particulate content of a sample having particulate diameters in the range of 0.001-10 microns. The apparatus comprises an evacuable chamber equipped with a chamber entrance through which a particle-laden gas stream enters. An inlet device, such as a capillary, communicates with the chamber entrance for inputting the particle-laden gas stream to the evacuable chamber. A laser is positioned to produce a focused laser beam which intersect the particle-laden gas stream at position approximately 0.1 mm from the chamber entrance. The laser beam has a power density sufficient to fragment and ionize particles entrained within the particle-laden gas stream.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: November 2, 1999
    Assignee: Lucent Technologies Inc.
    Inventor: William David Reents, Jr.
  • Patent number: 5955729
    Abstract: The invention provides surface plasmon resonance-mass spectroscopy for the rapid, sensitive and accurate investigation of molecular interactions coupled with the identification and quantification of the same. Methods of the invention include capturing an analyte present within a sample by an interactive surface layer on a real-time interaction analysis sensor, analyzing the analyte by surface plasmon resonance while the analyte is captured by the interactive surface layer, and identifying the captured analyte by desorbing/ionizing the analyte from the interactive surface layer while under vacuum within a mass spectrometer. Devices of the invention include a transparent material, a conductive material capable of supporting surface plasmon resonance affixed to the transparent material, an interactive surface affixed to the conductive material, and a means for exposing the interactive surface to the interior of a mass spectrometer without breaking the vacuum therein.
    Type: Grant
    Filed: September 6, 1996
    Date of Patent: September 21, 1999
    Assignee: Biacore AB
    Inventors: Randall W. Nelson, Jennifer R. Krone, Russell Granzow, Osten Jansson, Stefan Sjolander
  • Patent number: 5955731
    Abstract: A mass spectrometric analysis of the content of surfaces, it is necessary to bring the analyte molecules into the gas phase. This is done with a tightly focused, preferably pulsed laser beam. This laser beam is focused onto the surface with a mirror that is placed as close as possible to the analysed surface. In order to achieve a very small focal point, deflection and focusing of the laser beam is done with a single optical element. The evaporated material passes through a opening in the mirror into the mass spectrometer. It is also possible to let the evaporated material pass right next to the mirror into the mass spectrometer.
    Type: Grant
    Filed: September 5, 1997
    Date of Patent: September 21, 1999
    Inventors: Thorald Horst Bergmann, Claus-Peter Michael Heidmann
  • Patent number: 5917185
    Abstract: The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent.
    Type: Grant
    Filed: June 26, 1997
    Date of Patent: June 29, 1999
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Edward S. Yeung, Yu-chen Chang
  • Patent number: 5861629
    Abstract: Method of quantitatively detecting material in a sample, whereby the material is in the form of submicrometric particles covered by a photoemitting substance, and a device for practicing the method. The material in the sample is heated to a photoemitting state and subjected while in that state to photoemission measurement. The proportion of material in the sample is determined from the signal obtained from that measurement by comparison with empirical data obtained from a reference sample containing a previously detected quantity of the material or by comparison with data obtained for the material by calibration.
    Type: Grant
    Filed: June 18, 1996
    Date of Patent: January 19, 1999
    Assignee: Forschungszentrum Julich GmbH
    Inventors: Helmut Hackfort, Georg Hinzen
  • Patent number: 5855850
    Abstract: A photoionization detector includes a brittle substrate having a void micromachined therein with a void inlet and a void outlet. First and second electrodes are disposed in the void. An ultraviolet transparent member covers at least a portion of the void in which the electrodes are disposed. A gas sample passes through the void and is exposed to ultraviolet radiation from a UV source. Ionization of the sample is measured as current flowing between the electrodes.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: January 5, 1999
    Assignee: Rosemount Analytical Inc.
    Inventor: Fred C. Sittler
  • Patent number: 5834791
    Abstract: A process of producing a highly spin-polarized electron beam, including the steps of applying a light energy to a semiconductor device comprising a first compound semiconductor layer having a first lattice constant and a second compound semiconductor layer having a second lattice constant different from the first lattice constant, the second semiconductor layer being in junction contact with the first semiconductor layer to provide a strained semiconductor heterostructure, a magnitude of mismatch between the first and second lattice constants defining an energy splitting between a heavy hole band and a light hole band in the second semiconductor layer, such that the energy splitting is greater than a thermal noise energy in the second semiconductor layer in use; and extracting the highly spin-polarized electron beam from the second semiconductor layer upon receiving the light energy.
    Type: Grant
    Filed: October 30, 1997
    Date of Patent: November 10, 1998
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Tsutomu Nakanishi, Hiromichi Horinaka, Takashi Saka, Toshihiro Kato
  • Patent number: 5821060
    Abstract: A process for deoxyribonucleic acid (DNA) sequencing, mapping, and diagnostics which utilizes the differences between the chemical composition of DNA and that of peptide nucleic acids (PNAs) to provide DNA sequencing, mapping, or diagnostics using natural DNA fragments, rather than using radioisotopes, stable isotopes or fluorescent substances to label the DNAs. The process includes the steps of hybridizing PNA segments to complementary DNA segments which are fixed to a hybridization surface, or hybridizing DNA segments to complementary PNA segments which are fixed to a hybridization surface, and using mass spectrometric or non-mass spectrometric techniques to analyze the extent of hybridization at each potential hybridization site.
    Type: Grant
    Filed: August 2, 1996
    Date of Patent: October 13, 1998
    Assignee: Atom Sciences, Inc.
    Inventors: Heinrich F. Arlinghaus, K. Bruce Jacobson
  • Patent number: 5808309
    Abstract: The invention relates to apparatus for generating an electron beam with an ptical waveguide, a light source which is coupled on one end of the optical waveguide, a coating for generated electrons which is applied to the other end of the optical waveguide as well as field-generating means in order to lower the electron work function of the coating so far that a photoemission current can be generated. According to the invention a metal carbide is used as the coating.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: September 15, 1998
    Assignee: ACT Advanced Circuit Testing Gesellschaft fur Testsystementwicklung mbH
    Inventors: Rainer Spehr, Michael Schmitt, Jurgen Frosien
  • Patent number: 5808299
    Abstract: A monitor that photo-ionizes trace constituents within a quadrupole ion trap (QIT). The QIT may have a valve that discharges a gas specimen into a trap chamber or a gas line that continuously discharges a gas specimen into the QIT. The trap chamber is surrounded by a ring, and an extractor plate that has an orifice. The trace molecules within the air may be ionized at the nozzle of the valve by a photo-ionizer. Photo-ionizing at the valve nozzle provides a relatively high density of ionized molecules. The photo-ionizer may be either a pulsed light source or a continuous wave light source. The trace molecules are preferably ionized with energy between 8.0 and 11.0 electron volts (eV). The energy is selected to ionize the trace molecules without fragmenting the trace constituents. A radio frequency or other oscillating frequency voltage potential is applied to the ring to trap the ionized trace molecules within the trap chamber.
    Type: Grant
    Filed: February 18, 1997
    Date of Patent: September 15, 1998
    Assignee: Syagen Technology
    Inventor: Jack Syage
  • Patent number: 5763875
    Abstract: A mass spectrographic method and apparatus provide simultaneous quantification of multiple target species of gaseous neutral particles that may be laser sputtered from a sample. The invention employs non-resonant multiphoton ionization of the target species with a high intensity laser beam propagated toward a given extraction volume from which volume ions are withdrawn for quantification. In preferred embodiments, the given volume is defined by an acceptance aperture and a transverse energy acceptance interval which is itself defined by energy discrimination of the ions into bunches with a novel ion mirror. An inventive embodiment of ion mirror has four grids at different spacings and potentials with a second grid away from the acceptance aperture having a potential just below a third to separate out an undesired, low-energy ion bunch. Curves for simultaneously quantifying Ta.sup.+ ions with Ta.sup.++ ions are shown.
    Type: Grant
    Filed: July 26, 1994
    Date of Patent: June 9, 1998
    Inventors: Stefan Kaesdorf, Matthias Wagner, Hartmut Schroder
  • Patent number: 5760393
    Abstract: A time-of-flight mass spectrometer for measuring the mass-to-charge ratio of a sample molecule is described. The spectrometer provides independent control of the electric field experienced by the sample before and during ion extraction. Methods of mass spectrometry utilizing the principles of this invention reduce matrix background, induce fast fragmentation, and control the transfer of energy prior to ion extraction.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: June 2, 1998
    Assignee: PerSeptive Biosystems, Inc.
    Inventors: Marvin L. Vestal, Peter Juhasz
  • Patent number: 5747862
    Abstract: An electron emitting element including a semiconductor opto-electronic layer having a split valence band and capable of emitting a beam of spin-polarized electrons from an emitting surface thereof upon incidence of an excitation laser radiation upon the emitting surface, and a reflecting mirror formed on one of opposite sides of the opto-electronic layer remote from the emitting surface and cooperating with the emitting surface to effect multiple reflection therebetween of the incident laser radiation. The emitting element may be provided with a semiconductor light modulator element for modulating the intensity of the laser radiation incident upon the opto-electronic layer. A laser source may be formed integrally with the emitting element and disposed on the side of the opto-electronic layer remote from the emitting surface.
    Type: Grant
    Filed: September 22, 1993
    Date of Patent: May 5, 1998
    Assignees: Katsumi Kishino, Daido Tokushuko Kabushiki Kaisha
    Inventors: Katsumi Kishino, Toshihiro Kato
  • Patent number: 5705814
    Abstract: A scanning probe microscope and method having automated exchange and precise alignment of probes, wherein one or more additional stored probes for installation onto a probe mount are stored in a storage cassette or a wafer, a selected probe is aligned to a detection system, and the aligned probe is then clamped against the probe mount. Clamping is performed using a clamp which is disabled when removing a replacement probe from the storage cassette, enabled when installing the probe on the probe mount and disabled when releasing the probe at a later time for subsequent probe exchange. Probe alignment is automated using signals from the probe detection system or by forming an optical image of the probe using a camera or similar technique and determining probe positioning using pattern recognition processing of the probe image to allow probe removal and exchange without operator intervention. Techniques for error checking are employed to ensure proper probe installation and operation.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: January 6, 1998
    Assignee: Digital Instruments, Inc.
    Inventors: James M. Young, Craig B. Prater, David A. Grigg, Charles R. Meyer, William H. Hertzog, John A. Gurley, Virgil B. Elings
  • Patent number: 5631462
    Abstract: The present invention provides methods and apparatus for analyzing the particulate contents of a sample such that a high proportion of the sample particles are analyzed without discrimination against high electronegativity and high ionization potential elements. In an exemplary embodiment, the invention comprises an apparatus for analyzing the particulate content of a sample having particulate diameters in range of 0.001-10 microns. The apparatus comprises an evacuable chamber equipped with a chamber entrance through which a particle-laden gas stream enters. An inlet device, such as a capillary, communicates with the chamber entrance for inputting the particle-laden gas stream to the evacuable chamber. A laser is positioned to produce a focused laser beam which intersects the particle-laden gas stream at a position approximately 0.1 mm from the chamber entrance. The laser beam has a power density sufficient to fragment and ionize particles entrained within the particle-laden gas stream.
    Type: Grant
    Filed: January 17, 1995
    Date of Patent: May 20, 1997
    Assignee: Lucent Technologies Inc.
    Inventor: William D. Reents, Jr.
  • Patent number: 5627369
    Abstract: A time-of-flight mass spectrometer for measuring the mass-to-charge ratio of a sample molecule is described. The spectrometer provides independent control of the electric field experienced by the sample before and during ion extraction. Methods of mass spectrometry utilizing the principles of this invention reduce matrix background, induce fast fragmentation, and control the transfer of energy prior to ion extraction.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: May 6, 1997
    Assignee: PerSeptive Biosystems, Inc.
    Inventors: Marvin L. Vestal, Peter Juhasz
  • Patent number: 5625184
    Abstract: A time-of-flight mass spectrometer for measuring the mass-to-charge ratio of a sample molecule is described. The spectrometer provides independent control of the electric field experienced by the sample before and during ion extraction. Methods of mass spectrometry utilizing the principles of the invention reduce matrix background, induce fast fragmentation, and control the transfer of energy prior to ion extraction.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: April 29, 1997
    Assignee: PerSeptive Biosystems, Inc.
    Inventors: Marvin L. Vestal, Peter Juhasz
  • Patent number: 5594243
    Abstract: A laser desorption ionization instrument for measuring the molecular weight of large organic molecules includes a time of flight (TOF) mass spectrometer. The time of flight mass spectrometer includes a sample lock for holding, under vacuum, a plurality of samples to be analyzed. A sample may be inserted into and removed from the sample lock and into the mass spectrometer without breaking vacuum in the spectrometer. Signal processing electronics of the LDIM instrument include means for identifying quasi-molecular species of a molecule being measured. The instrument includes improvements in ion optics, microchannel plate detectors, laser irradiation of samples, and preparation of samples for measurement.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: January 14, 1997
    Assignee: Hewlett Packard Company
    Inventors: Scot R. Weinberger, Robert W. Egan, Thomas W. Hoppe, deceased, Ernst Gassmann, Martin M. Schar, Klaus O. Bornsen, E. Rocco Tarantino
  • Patent number: 5591947
    Abstract: A simple system for obtaining high dissociation yield in a single highly selective step, even at very high pumping powers, in the molecular laser isotope separation (MLIS) route of Uranium Hexafluoride (UF.sub.6), is described. In order to selectively excite and dissociate the desired isotope .sup.235 UF.sub.6 two beams with frequencies corresponding to the first and second energy excitation levels of this isotope at .omega..sub.1 =.omega..sub.0 and .omega..sub.2 =.omega..sub.0 +.omega..sub.12 respectively where .omega..sub.12 is the frequency difference between the first and second energy excitation levels, are simultaneously applied to the supercooled Uranium Hexafluoride molecular gas.
    Type: Grant
    Filed: September 21, 1994
    Date of Patent: January 7, 1997
    Assignee: Synergetic Resiurces Limited
    Inventor: Doros Andreou
  • Patent number: 5580733
    Abstract: Method for analyzing a nucleic acid molecule, without fragmenting the molecule, by vaporizing a mixture of the molecule and a matrix by illuminating the mixture with visible laser light absorbed by the matrix and not by the nucleic acid molecule. The method is useful for determining the nucleotide sequence of a polynucleotide by using mass spectrometry to determine the molecular weights of individual single-stranded nucleic acid molecules in a population including a plurality of single-stranded nucleic acid molecules generated from the polynucleotide, each molecule having a different molecular weight, and one defined terminus and one variable terminus which terminates at a specific nucleotide.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: December 3, 1996
    Assignee: Wayne State University
    Inventors: Robert J. Levis, Louis J. Romano
  • Patent number: 5576549
    Abstract: An electron generating assembly for an x-ray tube has a thermionic cathode and an electrode system for accelerating electrons emitted by the thermionic cathode, and an electron multiplier disposed in the electron path. In order to achieve a given electron beam density, the electron beam current emitted by the cathode can be reduced dependent on the multiplication factor of the electron multiplier, thereby extending the service life of the overall assembly. The electron multiplier can be controllable.
    Type: Grant
    Filed: June 28, 1995
    Date of Patent: November 19, 1996
    Assignee: Siemens Aktiengesellschaft
    Inventors: Erich Hell, Manfred Fuchs
  • Patent number: 5567935
    Abstract: A pulsed plume of laser ablated photo-ionizable material is emitted from a target in a vacuum, and a pulsed beam of light thereafter produces ionization of two plume sections straddling a central nonionized plume portion. A mask is provided, intermediate the plume and the laser generating the ionizing pulsed beam of light, to shield the central plume portion to prevent ionization thereof. The ionized portions of the plume are swept away from the vicinity of the non-ionized plume portion by a magnetic field, and the remaining nonionized portion passes through an aperture in a retrieval mask to produce the output of the atomic source.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: October 22, 1996
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Mario E. Fajardo, Michel Macler
  • Patent number: 5561344
    Abstract: A photo-ionization detector utilizes an ultraviolet (UV) lamp and is designed for detecting and measuring the concentration of volatile gases flowing between closely spaced parallel electrodes. One of the electrodes is formed to allow photons to pass into the space between the electrodes to ionize the volatile gases between the electrodes. The detector also incorporates an improved ionization chamber.
    Type: Grant
    Filed: March 7, 1995
    Date of Patent: October 1, 1996
    Assignee: RAE Systems, Inc.
    Inventor: Peter C. Hsi
  • Patent number: 5523572
    Abstract: A process of producing a highly spin-polarized electron beam, including the steps of applying a light energy to a semiconductor device comprising a first compound semiconductor layer having a first lattice constant and a second compound semiconductor layer having a second lattice constant different from the first lattice constant, the second semiconductor layer being in junction contact with the first semiconductor layer to provide a strained semiconductor heterostructure, a magnitude of mismatch between the first and second lattice constants defining an energy splitting between a heavy hole band and a light hole band in the second semiconductor layer, such that the energy splitting is greater than a thermal noise energy in the second semiconductor layer in use; and extracting the highly spin-polarized electron beam from the second semiconductor layer upon receiving the light energy.
    Type: Grant
    Filed: March 27, 1995
    Date of Patent: June 4, 1996
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Tsutomu Nakanishi, Hiromichi Horinaka, Takashi Saka, Toshihiro Kato
  • Patent number: 5498545
    Abstract: The system for analyzing multiple samples includes a plurality of portable of sample supports each for accommodating a plurality of samples thereon, and an identification mechanism for identifying each sample location on each of the plurality of sample supports. The mass spectrometer is provided for analyzing each of the plurality of samples when positioned within a sample receiving chamber, and a laser source strikes each sample with a laser pulse to desorb and ionize sample molecules. The support transport mechanism provided for automatically inputting and outputting each of the sample supports from the sample receiving chamber of the mass spectrometer. A vacuum lock chamber receives the sample supports and maintains at least one of the sample supports within a controlled environment while samples on another of the plurality of sample supports are being struck with laser pulses. The computer is provided for recording test data from the mass spectrometer and for controlling the operation of the system.
    Type: Grant
    Filed: July 21, 1994
    Date of Patent: March 12, 1996
    Inventor: Marvin L. Vestal
  • Patent number: 5461235
    Abstract: A mass spectrometry apparatus includes means to irradiate a specimen with a beam of radiation to desorb ions for mass analysis. The apparatus comprises means for deflecting and scanning the beam and attenuator means arranged to vary the attenuation of the beam such that the attenuation is a function of the beam position in the scan.
    Type: Grant
    Filed: December 21, 1993
    Date of Patent: October 24, 1995
    Inventors: John S. Cottrell, Milton Keynes
  • Patent number: 5432670
    Abstract: Ionization of air without the use of corona discharge tips, thereby to avoid the generation of particulates from corrosion of the corona tips, is accomplished by use of a laser beam focussed to a small focal volume of intense electric field adjacent a semiconductor chip. The electric field is sufficiently intense to ionize air. In the manufacture of a semiconductor circuit chip, during those steps which are conducted in an air environment, opportunity exists to remove from a surface of a chip, or wafer, charge acquired during the manufacturing process. The ionized air is passed along the chip surface. Ions in the air discharge local regions of the chip surface which have become charged by steps of a manufacturing process. By way of further embodiment of the invention, the ionization may be produced by injection of molecules of water into the air, which molecules are subsequently ionized by a laser beam and directed toward the chip via a light shield with the aid of a magnetic field.
    Type: Grant
    Filed: December 13, 1993
    Date of Patent: July 11, 1995
    Assignee: International Business Machines Corporation
    Inventors: John S. Batchelder, Vaughn P. Gross, Robert A. Gruver, Philip C. D. Hobbs, Kenneth D. Murray
  • Patent number: 5431714
    Abstract: In the process for investigating particles situated in a gas, a gas stream is guided past a miniaturized UV excimer radiator. In this case, the particles are ionized and subsequently filtered out, and the resultant photoelectrically induced current is measured. Since particles from different sources (petrol engine, diesel engine, cigarette smoke) exhibit a wavelength dependence which is characteristic of the source, by measurements at at least two wavelengths, which is readily possible when using UV excimer radiators with different gas fillings, pollutants can be detected according to the source.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: July 11, 1995
    Assignee: ABB Research Ltd.
    Inventors: Heinz K. Burtscher, Daniel A. Matter, Ulrich Kogelschatz
  • Patent number: 5397895
    Abstract: The present invention provides a photoionization mass spectroscopy flux monitor for gaseous species above a sample surface. It provides an in situ, real time, species specific, nonintrusive probe with a geometry compatible with conventional MBE growth chambers. Gaseous species are photoionized above a sample surface and the ionized gaseous species are extracted parallel to the sample surface and coupled into a mass spectrometer inlet adjacent to the sample surface. The geometry of the flux monitor allows for simultaneous coupling of a charged particle beam with the sample surface, for example for monitoring film growth with RHEED.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: March 14, 1995
    Assignee: The United States of America as represented by the Secretary of Commerce
    Inventors: Stephen R. Leone, Struppp Paul G., Russell V. Smilgys, April L. Alstrin
  • Patent number: 5393979
    Abstract: A photo-ionization detector utilizes an ultraviolet (UV) lamp for detecting and measuring the concentration of volatile gases flowing between closely spaced parallel electrodes. One of the electrodes is made of mesh to allow photons to pass into the space between the electrodes to ionize the volatile gases between the electrodes. The detector also incorporates an improved ionization chamber. In other embodiments, a plurality of gas discharge lamps, each generating a different photon energy, may be placed adjacent to a plurality of closely spaced electrodes, all electrodes in one ionization chamber, to detect and measure different types of volatile gases that may exist.
    Type: Grant
    Filed: May 12, 1993
    Date of Patent: February 28, 1995
    Assignee: RAE Systems, Inc.
    Inventor: Peter C. Hsi
  • Patent number: 5389786
    Abstract: The ablation threshold of a laser fluence with respect to the surface of a sample manufactured in a high vacuum chamber is determined by using the sample. The quantity of vacancy-type defects is determined by radiating a laser beam having a fluence slightly higher than the ablation threshold on the surface. At the same time, the quantities of adatom-type and kink-type defects are determined by radiating a pulsed laser beam having a fluence slightly lower than the ablation threshold on the surface repeatedly to obtain the relation between an emission yield and the number of laser pulses. The quantity of the adatom-type defects is obtained by determining the area (total quantity of emitted atoms) of a rapidly decreasing portion of the relation. The quantity of kink-type defects is obtained by determining a magnitude of an emission yield of a slowly decreasing portion of the relation.
    Type: Grant
    Filed: April 15, 1993
    Date of Patent: February 14, 1995
    Assignee: President of Nagoya University
    Inventors: Noriaki Itoh, Yasuo Nakai, Ken Hattori, Akiko Okano
  • Patent number: 5382794
    Abstract: Disclosed is an apparatus which can serve to detect, count, size discriminate and analyze the chemical composition of particles in the air or process gases. In a preferred embodiment, the particles enter via a capillary into a differentially pumped chamber. A pulsed laser which is continuously fired is focused at an opening in the chamber. When the particles come into the path of the laser beam, the particles are fragmented and ionized. A dual time of flight mass spectrum is produced, recorded with an oscilloscope and analyzed with a computer. The mass spectrum information enables the determination of the chemical nature and concentration of the species of the particles, the particle size and the elemental composition of airborne particles in real time. Once these parameters are determined the source of the particles can be determined and eliminated from the environment and process. Thus, the inventive apparatus is advantageously used in conjunction with a facility, i.e.
    Type: Grant
    Filed: December 29, 1993
    Date of Patent: January 17, 1995
    Assignee: AT&T Corp.
    Inventors: Stephen W. Downey, Adrian B. Emerson, Anthony M. Mujsce, Amy J. Muller, William D. Reents, Jr., James D. Sinclair, Alka Swanson
  • Patent number: 5371364
    Abstract: A system for signalling the presence of selected ion species in a gaseous sample of an ion mobility sensor, having a unidirectional field provided between first and second electrodes positioned a selected distance apart. An ionization source generates ions in the sensor and a trigger controller allows ions to enter the region between the first and second electrodes at a time t.sub.1. The ions then arrive at the second electrode at a time t.sub.2. A transimpedance amplifier converts the ion charges to voltage signals. The presence of selected ion species is determined by circuitry that is activated by the trigger controller at t.sub.2. The species are preferably analyzed by directing the amplifier output to an analog to digital converter and then to a digital signal processor. The ions may alternatively be analyzed by generating a logic pulse representing a selected ion species when the amplifier output exceeds a preset value.
    Type: Grant
    Filed: February 18, 1993
    Date of Patent: December 6, 1994
    Assignee: Thermo King Corporation
    Inventors: David K. Davies, John M. Zomp
  • Patent number: 5365063
    Abstract: A method and an apparatus for non-resonant photoionization of multiple species of neutral particles of a gas in which the neutral particles are ionized in an ionization space by a laser beam having a maximum intensity above the saturation intensity for ionizing neutral particles of multiple desired types. The ions so produced are extracted from the ionization space by an ion-optical system. The ionization of the desired types of neutral particles and/or the extraction of the produced ions are confined by light-optical or ion-optical means to a sharply limited space in which the intensity of the laser beam is above the saturation intensity or is negligibly low with respect to the ionization of neutral particles of interest, so that the number of extracted ions of the ion type of interest does not substantially increase when the laser beam intensity is further increased. The multiple ionized species can be quantitatively determined mass spectrographically in a single step.
    Type: Grant
    Filed: June 21, 1993
    Date of Patent: November 15, 1994
    Assignee: Der Wissenschaften E.B. Max-Planck-Gesellschaft Zur Foerderung
    Inventors: Stefan Kaesdorf, Hartmut Schroder
  • Patent number: 5338931
    Abstract: An improved photoionization ion mobility spectrometer is disclosed which utilizes a flashlamp as the source for ionization. A gas sample is introduced via a carrier gas into a ionization chamber which is part of the spectrometer cell. Ionizable molecules contained in the injected gas sample are ionized by the ultraviolet light emitted from the flashlamp. The ionized molecules are attracted by an electrostatic drift field into a drift chamber and travel therethrough against the flow of a drift gas counter-current thereto until they are captured by a collector located in the drift chamber opposite to the ionization chamber. A dopant with an effective ionization potential lower than the photon energy of the emitted light can be introduced into the ionization chamber to further improve the sensitivity and specificity.
    Type: Grant
    Filed: April 23, 1992
    Date of Patent: August 16, 1994
    Assignee: Environmental Technologies Group, Inc.
    Inventors: Glenn E. Spangler, Joseph E. Roehl, Gautam B. Patel, Alvin Dorman
  • Patent number: 5316635
    Abstract: A method for selectively photoionizing odd mass Zr atoms. Atomic vapours are subjected to three resonant and are non resonant laser pulses to raise the energy of Zr atoms from the J=2 ground state, to a J=1 first intermediate state, to a J=(second intermediate state and to a third intermediate state prior to ionization.
    Type: Grant
    Filed: May 22, 1992
    Date of Patent: May 31, 1994
    Assignee: Atomic Energy of Canada Limited/Energie Atomique du Canada Limitee
    Inventors: Lawrence W. Green, Glenn McRae
  • Patent number: 5316970
    Abstract: Ionization of air without the use of corona discharge tips, thereby to avoid the generation of particulates from corrosion of the corona tips, is accomplished by use of a laser beam focussed to a small focal volume of intense electric field adjacent a semiconductor chip. The electric field is sufficiently intense to ionize air. In the manufacture of a semiconductor circuit chip, during those steps which are conducted in an air environment, opportunity exists to remove from a surface of a chip, or wafer, charge acquired during the manufacturing process. The ionized air is passed along the chip surface. Ions in the air discharge local regions of the chip surface which have become charged by steps of a manufacturing process. By way of further embodiment of the invention, the ionization may be produced by injection of molecules of water into the air, which molecules are subsequently ionized by a laser beam and directed toward the chip via a light shield with the aid of a magnetic field.
    Type: Grant
    Filed: June 5, 1992
    Date of Patent: May 31, 1994
    Assignee: International Business Machines Corporation
    Inventors: John S. Batchelder, Vaughn P. Gross, Robert A. Gruver, Philip C. D. Hobbs, Kenneth D. Murray
  • Patent number: 5281538
    Abstract: A sample for analysis by Laser Desorption Mass Spectrometry is prepared by dissolving the sample material in a solvent and applying the solution to a matrix material applied to a target for a mass spectrometer. The matrix material is selected from the group consisting of (i) cis-Cinnamic Acid with the aromatic ring substituted by one or more groups which possess an electron pair on the atom adjacent to the ring; (ii) trans-Cinnamic Acid with the aromatic ring substituted by one or more groups which possess an electron pair on the atom adjacent to the ring; (iii) Benzoic Acid, with one or more substituent groups as described in (i); and (iv) Coumarin, with one or more substituent groups as described in (i).
    Type: Grant
    Filed: February 20, 1992
    Date of Patent: January 25, 1994
    Assignee: Finnigan Mat Limited
    Inventors: John S. Cottrell, Kuldip K. Mock
  • Patent number: 5271800
    Abstract: Hydrocarbon polymer coatings used in microelectronic manufacturing processes are anisotropically etched by atomic oxygen beams (translational energies of 0.2-20 eV, preferably 1-10 eV). Etching with hyperthermal (kinetic energy>1 eV) oxygen atom species obtains highly anisotropic etching with sharp boundaries between etched and mask-protected areas.
    Type: Grant
    Filed: July 12, 1991
    Date of Patent: December 21, 1993
    Assignee: The United States of America as represented by the Administrator of National Aeronautics and Space Administration
    Inventors: Steven L. Koontz, Jon B. Cross
  • Patent number: 5272338
    Abstract: An ion-beam based system enables quantitative analysis and visualization of a sample with atomic and molecular specificity. The system comprises a liquid metal ion source that directs a tightly focused beam of ions at the sample, the beam having an ion density that is insufficient to materially change the surface properties of the sample. A controller connected to the liquid metal ion source gates on the ion beam for a period of time that is sufficient to enable the ion source to achieve a tight focus of the beam at the sample and for further scanning the ion beam across the sample. A laser beam is positioned over the sample and has a wavelength that resonantly ionizes components of the sample that are liberated by action of the scanned ion beam. A detector measures the liberated ionized components and is connected to a display system that provides an image of the distribution of the species on surface of the sample.
    Type: Grant
    Filed: May 21, 1992
    Date of Patent: December 21, 1993
    Assignee: The Pennsylvania Research Corporation
    Inventors: Nicholas Winograd, Stephen J. Benkovic
  • Patent number: 5206594
    Abstract: Molecular ionization detection and analysis including processes and apparatus for photoionizing trace constituents in a carrier gas or effluent from a chromatograph in a manner that substantially increases the effective sensitivity. The invention uses a pulsed gas valve to introduce a high density gas sample into a vacuum system where the trace constituents in the jet are photoionized by an intense vacuum ultraviolet [VUV] pulse from a flashlamp. The ions are extracted from the beam under free molecular flow conditions. This source may be used with the ion energy analyzer to eliminate any interference due to background gases in the vacuum system and to provide mass analysis of the eluting trace constituents.
    Type: Grant
    Filed: May 11, 1990
    Date of Patent: April 27, 1993
    Assignee: Mine Safety Appliances Company
    Inventor: Edward C. Zipf