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May 2001

The Laboratory
in the News

Commentary by
Jeff Wadsworth

Uncovering
Hidden Defects
with Neutrons

The Human in the Mouse Mirror

The NIF Target Chamber—Ready
for the Challenge

Indoor Testing Begins Soon at
Site 300

Patents

Awards


Patents

Russell Hudyma
High Numerical Aperture Ring Field Projection System for Extreme Ultraviolet Lithography
U.S. Patent No. 6,183,095 B1
February 6, 2001
An all-reflective optical system for a projection photolithography camera has a source of extreme ultraviolet (EUV) radiation, a wafer, and a mask to be imaged on the wafer. The optical system includes a first concave mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror, and a sixth concave mirror. The system is figured so that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 12 degrees, and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 15 degrees. Four of the six reflecting surfaces have an aspheric departure of less than substantially 7 micrometers. Five of the six reflecting surfaces have an aspheric departure of less than substantially 14 micrometers. Each of the six reflecting surfaces has an aspheric departure of less than 16 micrometers.

Henry N. Chapman, Keith A. Nugent
Condenser for Ring-Field Deep-Ultraviolet and Extreme-Ultraviolet Lithography
U.S. Patent No. 6,186,632 B1
February 13, 2001
A condenser for use with a ring-field deep-ultraviolet or extreme- ultraviolet lithography system. A condenser includes a ripple-plate mirror that is illuminated by a collimated beam at grazing incidence. The ripple plate is a plate mirror onto which a series of channels has been formed along one axis to produce concave, undulating surfaces. Light incident along the channels is reflected onto a series of cones. The distribution of slopes on the ripple plate leads to a distribution of angles of reflection of the incident beam. This distribution has the form of an arc, with the extremes of the arc given by the greatest slope in the ripple plate. An imaging mirror focuses this distribution to a ring-field arc at the mask plane.

Russell Hudyma, David R. Shafer
High Numerical Aperture Ring Field Projection System for Extreme Ultraviolet Lithography
U.S. Patent No. 6,188,513 B1
February 13, 2001
An all-reflective optical system for a projection photolithography camera has a source of extreme ultraviolet (EUV) radiation, a wafer, and a mask to be imaged on the wafer. The optical system includes a first convex mirror, a second mirror, a third convex mirror, a fourth concave mirror, a fifth convex mirror, and a sixth concave mirror. The system is configured so that five of the six mirrors receive a chief ray at an incidence angle of less than substantially 9 degrees, and each of the six mirrors receives a chief ray at an incidence angle of less than substantially 14 degrees. Four of the six reflecting surfaces have an aspheric departure of less than substantially 12 micrometers. Five of the six reflecting surfaces have an aspheric departure of less than substantially 12 micrometers. Each of the six reflecting surfaces has an aspheric departure of less than substantially 16 micrometers.

Richard F. Post
Combined Passive Magnetic Bearing Element and Vibration Damper
U.S. Patent No. 6,191,515 B1
February 20, 2001
A magnetic bearing system contains magnetic subsystems that act together to support a rotating element in a state of dynamic equilibrium and dampen transversely directed vibrations. Mechanical stabilizers are provided to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by a collection of passive elements using permanent magnets to provide their magnetomotive excitation. In an improvement over U.S. Patent No. 5,495,221, a magnetic-bearing element is combined with a vibration-damping element to provide a single upper stationary dual-function element. The magnetic forces exerted by such an element enhance levitation of the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations, and suppress the effects of imbalance or inhibit the onset of whirl-type rotor-dynamic instabilities. Concurrently, this equilibrium is made stable against displacement-dependent drag forces of the rotating object from its equilibrium position.

Jeffrey D. Morse, Robert J. Contolini
Use of a Hard Mask for Formation of Gate and Dielectric Via Nanofilament Field-Emission Devices
U.S. Patent No. 6,193,870 B1
February 27, 2001
A process for fabricating a nanofilament field-emission device in which a via in a dielectric layer is self-aligned to a gate metal via structure located on top of the dielectric layer. A hard mask layer located on top of the gate metal layer is inert to the etch chemistry for the gate metal layer. In the hard mask layer, a via is formed by the pattern from etched nuclear tracks in a trackable material. The via formed by the hard mask will eliminate any erosion of the gate metal layer during the dielectric via etch. Also, the hard mask layer will protect the gate metal layer while the gate structure is etched back from the edge of the dielectric via, if such is desired. This method provides more tolerance for the electroplating of a nanofilament in the dielectric via and sharpening of the nanofilament.

Lloyd Hackel, C. Brent Dane
Laser Beam Temporal and Spatial Tailoring for Laser Shock Processing
U.S. Patent No. 6,198,069 B1
March 6, 2001
Techniques are provided for formatting laser pulse spatial shape and for effectively and efficiently delivering the laser energy to a work surface in the laser shock process. An appropriately formatted pulse helps to eliminate breakdown and generate uniform shocks. The invention uses a high-power laser technology capable of emitting the laser requirements for a high-throughput process, that is, a laser that can treat many square centimeters of surface area per second. The shock process has a broad range of applications, especially in the aerospace industry, where treating parts to reduce or eliminate corrosion failure is important. The invention may be used for treating metal components to improve strength and corrosion resistance. The invention has a broad range of applications for parts that are currently shot peened and/or require peening by means other than shot peening. Major applications for the invention are in the automotive and aerospace industries for components such as turbine blades, compressor components, and gears.

Christopher B. Darrow, Joe H. Satcher, Jr., Stephen M. Lane, Abraham P. Lee, Amy W. Wang
Implantable Medical Sensor System
U.S. Patent No. 6,201,980 B1
March 13, 2001
An implantable chemical sensor system for medical applications is described that permits selective recognition of an analyte using an expandable biocompatible sensor, such as a polymer, that undergoes a dimensional change in the presence of the analyte. The expandable polymer is incorporated into an electronic circuit component that changes its properties (for example, frequency) when the polymer changes dimension. As the circuit changes its characteristics, an external interrogator transmits a signal transdermally to the transducer, and the concentration of the analyte is determined from the measured changes in the circuit. This invention may be used for minimally invasive monitoring of blood glucose levels in diabetic patients.

Raymond M. Brusasco, Bernardino M. Penetrante, George E. Vogtlin, Bernard T. Merritt
NOx Reduction System Utilizing Pulsed Hydrocarbon Injection
U.S. Patent No. 6,202,407 B1
March 20, 2001
Hydrocarbon coreductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NOx to N2 in the presence of a catalyst. Exhaust NOx reduction of at least 50 percent in the emissions is achieved with the addition of less than 5-percent fuel as a source of the hydrocarbon coreductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NOx species removed.

James R. Smith
Lightweight Flywheel Containment
U.S Patent No. 6,203,924 B1
March 20, 2001
A lightweight flywheel containment composed of a combination of layers of various material that absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 meters per second and has an aerial density of less than 6.5 grams per square centimeter. The flywheel containment may, for example, be composed of an inner high-toughness structural layer, an energy-absorbing layer, and an outer support layer. Optionally, a layer of impedance-matching material may be used between the flywheel rotor and the inner high-toughness layer.

Holly E. Petersen, William D. Goward, Sol P. Dijaili
Fabrication of Precision High-Quality Facets on Molecular Beam Epitaxy Material
U.S. Patent No. 6,204,189 B1
March 20, 2001
Fabricating mirrored vertical surfaces on semiconductor layered material grown by molecular beam epitaxy (MBE). Low-energy, chemically assisted ion-beam etching is employed to prepare mirrored vertical surfaces on MBE-grown IIIŠV materials under unusually low concentrations of oxygen in evacuated etching atmospheres of chlorine and xenon ion beams. Ultraviolet-stabilized, smooth-surfaced photoresist materials contribute to highly vertical, high-quality mirrored surfaces during the etching.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



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UCRL-52000-01-5 | May 25, 2001