X-ray thickness gauge
First Claim
1. A device for measuring properties of a thin-film disposed on a layered structure using scattering X-rays, said device comprising:
- a source adapted to produce X-rays;
a curved surface positioned between said source and said thin-film, with the surface being in fixed orientation with respect to the layered structure and adapted to focus the X-rays onto a first focal area of the layered structure with one point of said area having X-rays impinging thereon at varying angles of incidence, with a reflected X-ray being associated with each of said plurality of X-rays;
a detector positioned to sense said reflected X-rays, said detector adapted to produce a signal corresponding to an angle of reflection and an intensity of each of the reflected X-rays sensed; and
a processor means, connected to receive signals produced by the detector, for determining properties of the thin-film based upon a comparison of the intensity and the angle of reflection of the reflected X-rays sensed, the properties including thin-film thickness.
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Accused Products
Abstract
A monochromator positioned in the path of a plurality of X-rays to simultaneously impinge the plurality of X-rays onto a thin-film at various angles of incidence, typically greater than a critical angle ψc. The monochromator may be cylindrically or toroidally shaped, defining two focal areas with a source of X-rays positioned at the first focal point and a sample containing the thin-film layer positioned at the second focal point. A position sensitive detector is positioned to sense monochromatic X-rays reflected from the thin-film and produce a signal corresponding to both intensity and an angle of reflection of the monochromatic X-rays sensed. A processor is connected to receive signals produced by the detector to determine, as a function of intensity and angle of reflection of the monochromatic X-rays impinging on the detector, various properties of the structure of the thin-film layer, including the thickness, density and smoothness.
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Citations
31 Claims
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1. A device for measuring properties of a thin-film disposed on a layered structure using scattering X-rays, said device comprising:
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a source adapted to produce X-rays; a curved surface positioned between said source and said thin-film, with the surface being in fixed orientation with respect to the layered structure and adapted to focus the X-rays onto a first focal area of the layered structure with one point of said area having X-rays impinging thereon at varying angles of incidence, with a reflected X-ray being associated with each of said plurality of X-rays; a detector positioned to sense said reflected X-rays, said detector adapted to produce a signal corresponding to an angle of reflection and an intensity of each of the reflected X-rays sensed; and a processor means, connected to receive signals produced by the detector, for determining properties of the thin-film based upon a comparison of the intensity and the angle of reflection of the reflected X-rays sensed, the properties including thin-film thickness. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A device for measuring the structure of a thin-film disposed on a substrate, comprising:
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an X-ray reflector defining a focal area proximate to the thin-film; a source directing a plurality of X-rays onto the reflector, with the reflector directing the plurality of X-rays as a bundle of monochromatic X-rays onto said thin-film at a plurality of incident angles greater than the critical angle (ψ
c), with each of the monochromatic X-rays reflecting from the thin-film at an angle of reflection corresponding to an angle of incidence, the reflector being a curved monochromator defining at least one focal point proximate to the substrate, whereby the curved monochromator simultaneously directs the plurality of X-rays onto the thin-film at varying angles of incidence;a detector positioned to sense X-rays reflected from the thin-film along a plane transverse to the plane of the thin-film, the detector producing a signal corresponding to an intensity and a spatial position of the transverse X-ray in the plane, with each spatial position in the plane corresponding to an angle of reflection; and a processor means connected to receive signals produced by the detector for determining physical properties of the thin-film based upon all signals received by the detector, the physical properties including the mass per unit area of the thin-film. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
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23. A device for measuring the properties of a thin-film disposed on a substrate, defining a substrate-thin-film interface, comprising:
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a source of X-rays adapted to produce X-rays; an X-ray reflector positioned in the path of the X-rays and adapted to simultaneously impinge onto at least one point of the thin-film a plurality of said X-rays at a plurality of incident angles with each of the plurality of X-rays reflecting from the thin-film at an angle of reflection, defining reflected X-rays with the angle of reflection corresponding to an angle of incidence; a detector positioned to sense said reflected X-rays reflected from the thin-film and produce a signal corresponding to the intensity and an angle of reflection of the reflected X-rays sensed; and a processor means connected to receive signals produced by the detector for determining properties of the thin-film based upon a comparison of the intensity and the angle of reflection of the reflected X-rays sensed, the properties including thin-film thickness, thin-film density and a relative smoothness between the surface of the thin-film and the smoothness of the substrate-thin-film interface. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31)
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Specification