Patents


Ronald B. Musket, John D. Porter, James M. Yoshiyama, and Robert J. Contolini
Vapor Etching of Nuclear Tracks in Dielectric Materials
U.S. Patent 6,033,583
March 7, 2000
A process involving vapor etching of nuclear tracks in dielectric materials for creating high-aspect-ratio (length much greater than diameter) isolated cylindrical holes in dielectric materials that have been exposed to high-energy atomic particles. The process includes cleaning the surface of the tracked materials and exposing the cleaned surface to a vapor of a suitable etchant. Independent control of the temperatures of the vapor and the tracked materials provides the means to vary separately the etch rates for the latent track region and the nontracked material. As a rule, the tracked regions etch at a greater rate than the nontracked regions. In addition, the vapor-etched holes can be enlarged and smoothed by subsequent dipping in a liquid etchant. The 20- to 1,000-nanometer-diameter holes resulting from the vapor etching process can be useful as molds for electroplating nanometer-size filaments, etching gate cavities for deposition of nanocones, developing high-aspect-ratio holes in trackable resists, and filters for a variety of molecular-size particles in virtually any liquid or gas by selecting the dielectric material that is compatible with the liquid or gas of interest.

Robert W. Petersen
L-Connect Routing of Die Surface Pads to the Die Edge for Stacking in a 3-D Array
U.S. Patent 6,034,438
March 7, 2000
Integrated circuit chips and method of routing the interface pads from the face of the chip or die to one or more sidewall surfaces of the die. The interconnection is routed from the face of the die to one or more edges of the die, then routed over the edge of the die and onto the side surface. A new pad is then formed on the sidewall surface, which allows multiple dies or chips to be stacked in a three-dimensional array, while enabling follow-on signal routing from the sidewall pads. The routing of the interconnects and formations of the sidewall pads can be carried out in an L-connect or L-shaped routing configuration, using a metallization process such as laser pantography.


M. Leslie Carman and Robert T. Taylor
System for Enhanced Longevity of In Situ Microbial Filter Used for Bioremediation
U.S. Patent 6,036,852
March 14, 2000
An improved method for in situ microbial filter bioremediation in which the filter emplaced in an aquifer has increasing operational longevity. A method for generating a microbial filter of sufficient catalytic density and thickness, which has a longer interval before replenishment, improved bacteria attachment and detachment characteristics, and endogenous stability under in situ conditions. A system for in situ field water remediation.


Lloyd A. Hackel, C. Brent Dane, Shamasundar N. Dixit, Matthew Everett, and John Honig
Laser Illuminator and Optical System for Disk Patterning
U.S. Patent 6,037,565
March 14, 2000
Magnetic recording media are textured over areas designated for contact in order to minimize friction with data-transducing heads. In fabricating a hard disk, an aluminum-nickel-phosphorous substrate is polished to a specular finish. A mechanical means is then used to roughen an annular area intended to be the head contact band. An optical and mechanical system allows thousands of spots to be generated with each laser pulse, and then the textured pattern is rapidly generated with a low-repetition-rate laser and an uncomplicated mechanical system. The system uses a low-power laser, a beam expander, a specially designed phase plate, a prism to deflect the beam, a lens to transmit the diffraction pattern to the far field, a mechanical means to rotate the pattern, and a trigger system to fire the laser when sections of the pattern are precisely aligned. The system generates an annular segment of the desired pattern with which the total pattern is generated by rotating the optical system about its optic axis, sensing the rotational position, and firing the laser as the annular segment rotates into the next appropriate position. This marking system can be integrated into a disk-sputtering system for manufacturing magnetic disks, streamlining the manufacturing process.


Robert S. Strait, Peter K. Pearson, and Sailes K. Sengupta
Method and System for Normalizing Biometric Variations to Authenticate Users from a Public Database and Ensure Individual Biometric Data Privacy
U.S. Patent 6,038,315
March 14, 2000
A password system comprising a set of code words spaced apart from one another by a hamming distance (HD) that exceeds twice the variability that can be projected for a series of biometric measurements for a particular individual but is less than the HD that can be encountered between two individuals. To enroll an individual, a biometric measurement is taken and exclusive-OR-functioned with a random code word to produce a reference value. To verify the individual later, a biometric measurement is taken and exclusive-OR-functioned with the reference value to reproduce the original random code word or its approximation. If the reproduced value is not a code word, the nearest code word to it is found, and the bits that were corrected to produce the code word are also toggled in the biometric measurement taken and the code word generated during enrollment. The correction scheme can be implemented by any conventional error correction code, such as Reed-Muller code R(m,n). In the implementation using a hand geometry device, an R(2.5) code has been used in this invention. The code word and biometric measurement can then be used to see if the individual is an authorized user. Conventional Diffie-Hellman public key encryption schemes and hashing procedures can then be used to secure the communication lines carrying the biometric information and to secure the database of authorized users.


Bernardino M. Penetrante, George E. Vogtlin, Bernard T. Merritt, and Raymond M. Brusasco
Plasma-Assisted Catalytic Storage Reduction System
U.S. Patent 6,038,853
March 21, 2000
A two-stage method for NOx reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a nonthermal plasma treatment of Nx gases in an oxygen-rich exhaust and is intended to convert nitrous oxide (NO) to nitrogen dioxide (NO2) in the presence of oxygen and hydrocarbons. The second stage employs a lean NOx trap to convert such NO2 to environmentally benign gases that include NO2, carbon dioxide, and water. By preconverting NO to NO2 in the first stage with a plasma, the efficiency of the second stage for NOx reduction is enhanced. The method allows for enhanced NOx reduction in vehicular engine exhausts, particularly those having relatively high sulfur content.


Bernardino M. Penetrante, George E. Vogtlin, Bernard T. Merritt, and Raymond M. Brusasco
Plasma Regenerated Particulate Trap and NOx Reduction System
U.S. Patent 6,038,854
March 21, 2000
A noncatalytic two-stage process for removal of NOx and particulates from engine exhaust comprising a first stage where plasma converts nitrous oxide (NO) to nitrogen dioxide (NO2) in the presence of oxygen and hydrocarbons and a second stage-which preferably occurs simultaneously with the first stage-that converts NO2 and carbon soot particles to environmentally benign gases that include N2 and carbon dioxide (CO2). By preconverting NO to NO2 in the first stage, the efficiency of the second stage for NOx reduction is enhanced, in that carbon soot from trapped particulates is simultaneously converted to CO2 when reacting with the NO2 (that converts to diatomic nitrogen, or N2). The nitrogen exhaust components remain in the gas phase throughout the process, with no accompanying adsorption.


Joe N. Lucas
Rapid Method for Measuring Clastogenic Fingerprints Using Fluorescence In Situ Hybridization
U.S. Patent 6,043,037
March 28, 2000
A method for determining a clastogenic signature of a sample of chromosomes by quantifying a frequency of a first type of chromosome aberration present in the sample; quantifying the frequency of a second, different type of chromosome aberration present in the sample; and comparing the frequencies of the first type and second type of chromosome aberration. A method is also provided for using that clastogenic signature to identify a clastogenic agent or dosage to which the cells were exposed.


Jeffrey D. Morse, Robert J. Contolini, Ronald G. Musket, and Anthony F. Bernhardt
Formation of Nanofilament Field Emission Devices
U.S. Patent 6,045,678
April 4, 2000
A process for fabricating high-aspect-ratio, electroplated nanofilament structure devices for field emission displays. In the process, a via, or channel, is formed in a dielectric layer and is self-aligned to a via in the gate metal structure located on top of the dielectric layer. The desired diameter of the via in the dielectric layer is on the order of 50 to 200 nanometers, with an aspect ratio of 5:10. In one embodiment, after the via in the dielectric layer is formed, the gate metal is passivated and a plating enhancement layer is deposited at the bottom of the via. The nanofilament is then electroplated in the via, after which the gate passification layer is removed, the dielectric etched back, and the nanofilament sharpened. A hard mask layer may be deposited on top of the gate metal and removed following electroplating of the nanofilament.


Awards


Charles Alcock, former head of Lawrence Livermore's Institute for Geophysics and Planetary Physics, has won the American Astronomical Society's Beatrice Tinsley Prize. Awarded once every two years since 1986, the Tinsley Prize recognizes "an outstanding research contribution to astronomy or astrophysics, of an exceptionally creative or innovative character."
Alcock was recognized for his research into the nature of dark matter in the universe, which is invisible but thought to comprise most of the universe's mass. He and an international research team have been searching the Milky Way, looking for occasional amplifications of starlight from outside the galaxy caused by the gravitational effects of dark matter. They are testing the hypothesis that a significant fraction of the dark matter in the halo of the Milky Way is made up of objects like brown dwarfs or planets, which have come to be known as massive compact halo objects, or MACHOs. The work, which began in 1996, ended its data-collection phase at the beginning this year. Up ahead, says Alcock, is the ". . . tremendous job to analyze the data."
Alcock says he knew Tinsley, a New Zealand-born astronomer, and is honored to receive the award bearing her name. "She was very original. She made stunning contributions in astronomy," he says. He also says he owes thanks to all his collaborators and to the Laboratory for allowing him to pursue the study.

Don Correll, director of the Laboratory's Science & Technology Education Program (STEP), has been awarded Fusion Power Associates' Special Award for Education. He was one of three recipients of the special award during the association's annual symposium in July.
Steve Dean, president of Fusion Power Associates, cited Correll's ". . . dedication and efforts to explain the fusion message to students, teachers, and the general public [which] have been a great service to our program and to our country."
Correll received his Ph.D. in physics from the University of California at Irvine in 1976 and was named an American Physical Society fellow in 1993. He joined the Laboratory in 1976 and held a variety of positions in the laser fusion program before being named director of STEP. Recently, he was also named point-of-contact for Laboratory postdoctoral fellows.
In the area of education, Correll has served on the Laboratory's Lawrence Fellowship Committee, Undergraduate Scholarship Committee, Student Policy Committee, and Lawrence Livermore-University of California at Davis Summer Institute Committee.

Mark Herrmann, a postdoctoral fellow working in the Laboratory's Defense and Nuclear Technologies Directorate, has been selected by the American Physical Society as this year's recipient of its Award for Outstanding Doctoral Dissertation in Plasma Physics. Herrmann, whose Ph.D. is from Princeton University, will receive the award during the society's meeting this month in Quebec City, Canada.
The citation on the award will read, "With elegant use of analytical theory and computation, and insightful comparisons to experiment, this thesis lays the foundation for how radio frequency waves might cool fusion byproducts in a tokamak."
Herrmann joined the Laboratory as a postdoctoral fellow in 1998. In 1990, he attended the Laboratory's Summer Institute in Applied Physics.


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