US6038280A
Expired / Lapsed
US
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Method and apparatus for measuring the thicknesses of thin layers by means of x-ray fluorescence
Assignee: Immobiliengesellschaft Helmut Fischer GmbH and Co KG
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Filing: 1998-03-12
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Granted: 2000-03-14
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Expires: 2018-03-12
Abstract
Abstract The invention relates to a method for measuring the thicknesses of thin layers by X-ray fluorescence, in which a specimen having the layer to be studied is positioned in view and subsequently X-radiation is directed onto the layer to be studied and emitted fluorescent radiation is detected by means of a radiation detector and the layer thickness is determined, in which on positioning the specimen there is a focussing by adjusting a focussing element along its optical axis and the position of the focussing element is determined with the layer in focus. An apparatus for layer thickness measurement with X-ray fluorescence according to the invention having a X-ray tube, a detector and an observing device with a focussing element provides for the latter to be movably mounted along its optical axis and provided with a position measuring device. This obviates the need for having to move a workpiece-carrying table in such a way that the work surface comes to rest at a predetermined, specific measuring distance or spacing.
Inventors
- 👤 Volker Rossiger
- 👤 Karl-Heinz Kaiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:25
CPC Classifications
G; G01; G01B; G01B15/00; G01B15/02; G01N; G01N23/00; G01N23/22; G01N23/223; G01N2223/00; G01N2223/07; G01N2223/076
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
113 words
A method for measuring thickness of a layer by X-ray fluorescence comprising: positioning a specimen having a layer to be studied in a view of an X-ray source; directing x-rays from the x-ray source onto the layer being studied which causes fluorescent radiation to be emitted from the layer; detecting the fluorescent radiation with a detector; adjusting a focusing device along an optical axis to focus an image of the specimen; determining a position of the focusing device when the image of the specimen is in focus; and producing a thickness measurement which is corrected in response to the fluorescent radiation detected by the detector and the determined position of the focusing element.
Claim 2
Independent Claim
113 words
A method for measuring thickness of a layer by X-ray fluorescence comprising: positioning a specimen having a layer to be studied in a view of an X-ray source; directing x-rays from the x-ray source onto the layer being studied which causes fluorescent radiation to be emitted from the layer; detecting the fluorescent radiation with a detector; adjusting a focusing device along an optical axis to focus an image of the specimen; determining a position of the focusing device when the image of the specimen is in focus; and producing a thickness measurement which is corrected in response to the fluorescent radiation detected by the detector and the determined position of the focusing element.
Claim 3
Dependent Claim
17 words
A method in accordance with claim 1 wherein: the position of the focusing element is electrically determined.
Claim 4
Dependent Claim
28 words
A method in accordance with claim 1 wherein; the adjusting of the focusing element along an optical axis to focus the image of the specimen is performed automatically.
Claim 5
Dependent Claim
28 words
A method in accordance with claim 2 wherein; the adjusting of the focusing element along an optical axis to focus the image of the specimen is performed automatically.
Claim 6
Dependent Claim
26 words
A method in accordance with claim 3 wherein: the adjusting of the focusing element produces a maximum contrast in the image produced by the focusing element.
Claim 7
Dependent Claim
26 words
A method in accordance with claim 4 wherein: the adjusting of the focusing element produces a maximum contrast in the image produced by the focusing element.
Claim 8
Dependent Claim
21 words
A method in accordance with claim 1 wherein: a camera and a screen displays the image produced by the focusing element.
Claim 9
Dependent Claim
51 words
A method in accordance with claim 1 wherein: correction of the thickness measurement is performed by a transformation T(z,z0) of a measurement sp(z) obtained from an actually measured distance z of the layer from the detector to a measured result sp(z0) for a desired measurement distance z0 corresponding to sp(z0)=T(z,z0) sp(z).
Claim 10
Independent Claim
116 words
An apparatus for measuring thickness of a layer of a specimen by X-ray fluorescence comprising: an X-ray source providing X-rays for irradiating the specimen which causes flourescent radiation to be emitted from the layer; a detector which detects the flourescent radiation emitted by the specimen; a focusing device which is adjustable along an optical axis to focus an image of the specimen; a position measuring device for measuring a position of the focusing element when the image of the specimen is in focus; and an evaluation unit for processing the position of the focusing element when the image is in focus and the radiation detected by the detector to produce a thickness measurement which is corrected.
Claim 11
Independent Claim
116 words
An apparatus for measuring thickness of a layer of a specimen by X-ray fluorescence comprising: an X-ray source providing X-rays for irradiating the specimen which causes flourescent radiation to be emitted from the layer; a detector which detects the flourescent radiation emitted by the specimen; a focusing device which is adjustable along an optical axis to focus an image of the specimen; a position measuring device for measuring a position of the focusing element when the image of the specimen is in focus; and an evaluation unit for processing the position of the focusing element when the image is in focus and the radiation detected by the detector to produce a thickness measurement which is corrected.
Claim 12
Dependent Claim
15 words
An apparatus in accordance with claim 9 wherein: the position measuring device is a potentiometer.
Claim 13
Dependent Claim
22 words
An apparatus in accordance with claim 9 further comprising: a camera and screen which displays the image produced by the focusing element.
Claim 14
Dependent Claim
15 words
An apparatus in accordance with claim 9 wherein: the focusing element is an autofocusing device.
Claim 15
Dependent Claim
15 words
An apparatus in accordance with claim 10 wherein: the focusing element is an autofocusing device.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-03-14 | 2003-09-13 | 2004-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-03-14 | 2007-09-13 | 2008-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-03-14 | 2011-09-13 | 2012-03-14 | $7700.00 | Window Closed / Lapsed |