Zewu Z Chen

US Patent:

6829327, Dec 7, 2004

Filed:

Sep 22, 2000

Appl. No.:

09/667966

Inventors:

Zewu Chen - Ballston Lake NY

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

G01N 23223

US Classification:

378 44, 378 82, 378 84

Abstract:

An improved total-reflection x-ray fluorescence (TXRF) apparatus using a doubly-curved optic is presented for use in detecting foreign matter on surfaces, for example, semiconductor wafers. The apparatus includes an x-ray source, a doubly-curved x-ray optic for diffracting and focusing the x-rays, a surface onto which at least some of the diffracted x-rays are directed, and an x-ray detector for detecting resultant x-ray fluorescence emitted by any foreign matter present on the surface One or more apertures may be provided for limiting the dispersion angle of the x-rays. The crystal or multi-layer doubly-curved optic typically adheres to Braggs law of x-ray diffraction may be curved to a toroidal, ellipsoidal, spherical, parabolic, hyperbolic, or other doubly-curved shape. An apparatus for diffracting x-rays is also presented. The apparatus includes an x-ray source and image defining an optic circle of radius R an x-ray optic having a surface of radius R and a plurality of atomic planes which intersect the surface at an angle , wherein the radius of the atomic planes R is defined by the equation R =2R cos.

US Patent:

6934359, Aug 23, 2005

Filed:

Dec 19, 2003

Appl. No.:

10/742414

Inventors:

Zewu Chen - Ballston Lake NY, US
David M. Gibson - Voorheesville NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

G01N023/223

US Classification:

378 84, 378 45

Abstract:

X-ray fluorescence (XRF) spectroscopy systems and methods are provided. One system includes a source of x-ray radiation and an excitation optic disposed between the x-ray radiation source and the sample for collecting x-ray radiation from the source and focusing the x-ray radiation to a focal point on the sample to incite at least one analyte in the sample to fluoresce. The system further includes an x-ray fluorescence detector and a collection optic comprising a doubly curved diffracting optic disposed between the sample and the x-ray fluorescence detector for collecting x-ray fluorescence from the focal point on the sample and focusing the fluorescent x-rays towards the x-ray fluorescence detector.

US Patent:

7023955, Apr 4, 2006

Filed:

Aug 12, 2003

Appl. No.:

10/639359

Inventors:

Zewu Chen - Schenectady NY, US
Shinichi Terada - Uji Kyoto, JP

Assignee:

X-Ray Optical System, Inc. - East Greenbush NY

International Classification:

G01N 23/223

US Classification:

378 44, 378147

Abstract:

Measurement technique and apparatus for examining a region of a patterned surface such as an integrated circuit (IC). Excitation x-ray, neutron, particle-beam or gamma ray radiation is directed toward a two-dimensional sample area of the IC. Emissions (e. g. , x-ray fluorescence—XRF) from the sample area are detected. A mask is placed in a planar radiation path formed by the source, detector and the sample area, and in one embodiment moveable relative to the sample area. The mask includes an elongate aperture to substantially confine the excitation radiation directed to the sample area, and the emissions from the sample area, to the planar radiation path when arranged parallel to a first axis of the two-dimensional sample area. The invention allows predictive measurement of feature characteristics in active circuit regions of the IC, using sample areas outside of these regions.

US Patent:

7035374, Apr 25, 2006

Filed:

Feb 1, 2005

Appl. No.:

11/048146

Inventors:

Zewu Chen - Schenectady NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

G21K 1/06

US Classification:

378 84, 378 85

Abstract:

Devices for improving the capturing and utilization of high-energy electromagnetic radiation, for example, x-rays, gamma rays, and neutrons, for use in physical, medical, and industrial analysis and control applications are disclosed. The devices include optics having a plurality of optical crystals, for example, doubly-curved silicon or germanium crystals, arranged to optimize the capture and redirection of divergent radiation via Bragg diffraction. In one aspect, a plurality of optic crystals having varying atomic diffraction plane orientations are used to capture and focus divergent x-rays upon a target. In another aspect, a two- or three-dimensional matrix of crystals is positioned relative to an x-ray source to capture and focus divergent x-rays in three dimensions.

US Patent:

7072439, Jul 4, 2006

Filed:

Jun 1, 2004

Appl. No.:

10/858173

Inventors:

Ian Radley - Glenmont NY, US
Thomas J. Bievenue - Delmar NY, US
Brian W. Gallagher - Guilderland NY, US
Stuart M. Shakshober - Hudson NY, US
Zewu Chen - Schenectady NY, US
Michael D. Moore - Alplaus NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

G01N 23/223

US Classification:

378 47

Abstract:

A technique for analyzing fluids by means of x-ray fluorescence applicable to any fluid, including liquids and gases, which emit x-ray fluorescence when exposed to x-rays. The apparatus includes an x-ray source () including an x-ray tube () having improved heat dissipating properties due to a thermally-conductive, dielectric material (). The x-ray tube also includes means for aligning () the tube with the source housing whereby the orientation of the x-ray beam produced by the source can be optimized, and stabilized over various operating conditions. The method and apparatus may also include an x-ray detector having a small-area, for example, a PIN-diode type semiconductor x-ray detector (), that can provide effective x-ray detection at room temperature. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

US Patent:

7110506, Sep 19, 2006

Filed:

Jun 3, 2004

Appl. No.:

10/859818

Inventors:

Ian Radley - Glenmont NY, US
Thomas J. Bievenue - Delmar NY, US
Brian W. Gallagher - Guilderland NY, US
Stuart M. Shakshober - Hudson NY, US
Zewu Chen - Schenectady NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

H01J 35/10

US Classification:

378141, 378142, 378199

Abstract:

A method and device for cooling and electrically-insulating a high-voltage, heat-generating component, for example, an x-ray tube () for analyzing fluids by means of x-ray fluorescence. The device includes an x-ray source () including an x-ray tube () having improved heat-dissipating properties due to the thermal coupling of the x-ray tube with a thermally-conductive, dielectric material (). The device may include a base assembly () mounted to the component for conducting heat away from the component while electrically isolating the component. In one aspect of the invention, the base assembly includes two copper plates () separated by a dielectric plate (). The dielectric plate minimizes or prevents the leakage of current through the base assembly (). One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

US Patent:

7206375, Apr 17, 2007

Filed:

Dec 1, 2005

Appl. No.:

11/291349

Inventors:

Zewu Chen - Schenectady NY, US
Walter Gibson - Voorheesville NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

G01F 23/06

US Classification:

378 51, 378 53, 378 84

Abstract:

Compact, low-power-consuming systems and methods for exposing samples to high-energy radiation, for example, for exposing samples to x-rays for implementing x-ray absorption near edge analysis (XANES). The systems and methods include a low-power-consuming radiation source, such as an x-ray tube; one or more tunable crystal optics for directing and varying the energy of the radiation onto a sample under analysis; and a radiation detecting device, such as an x-ray detector, for detecting radiation emitted by the sample. The one or more tunable crystal optics may be doubly-curved crystal optics. The components of the system may be arranged in a collinear fashion. The disclosed systems and methods are particularly applicable to XANES analysis, for example, XANES analysis of the chemical state of chromium or another transition metal in biological processes.

US Patent:

7209545, Apr 24, 2007

Filed:

Jun 3, 2004

Appl. No.:

10/859901

Inventors:

Ian Radley - Glenmont NY, US
Thomas J. Bievenue - Delmar NY, US
Brian W. Gallagher - Guilderland NY, US
Stuart M. Shakshober - Hudson NY, US
Zewu Chen - Schenectady NY, US
Michael D. Moore - Alplaus NY, US

Assignee:

X-Ray Optical Systems, Inc. - East Greenbush NY

International Classification:

H01J 35/30

US Classification:

378137, 378193

Abstract:

An x-ray source assembly () and method of operation are provided having enhanced output stability. The assembly includes an anode () having a source spot upon which electrons () impinge and a control system () for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure () notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.