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US6167355A Expired / Lapsed US ⏱️ 0.0 years remaining

High accuracy particle dimension measurement system

Assignee: KLA Tencor Technologies Corp
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Filing: 1999-06-29
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Granted: 2000-12-26
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Expires: 2019-06-29
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Abstract

Abstract A measurement tool connects to an automatic inspection machine for identifying and measuring microscopic dimensions such as area, diameter, height and line width of defects and lines of a photographic mask. An operator draws a rough region of interest around a feature and the tool automatically identifies the feature and calculates its dimensions. For features less than one micron in size, the size of light photons interferes with measurement, so a non-linear polynomial calibration curve is developed for each machine. Features of known sizes are measured on a production machine to produce a calibration curve for each type of defect or line. Features of unknown sizes are measured on the same machine and the measured size in pixels are calibrated using the calibration curve to return a more accurate reading in microns. To determine a dimension, the type of a feature is determined by using a bounding box and light transitions of an intensity profile of the feature; multiple regions of interest are developed for each feature to accommodate angled lines; columns of pixels in each region of interest are summed to produce a light intensity distribution profile for each region of interest; total flux is determined from each profile and the best flux measurement is used to calculate a dimension of the feature. A good image of a feature is obtained by subtracting a reference image from an original image if a profile is of low quality. For lines separated by less than one resolution unit, a fall-width half-maximum technique is used to calculate line width.

Inventors

  • 👤 Peter J. Fiekowsky

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 10:02
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95607; G03; G03F; G03F1/00; G03F1/68; G03F1/82; G03F1/84; G01N2021/95676

Claims Analysis

Total Claims: 60
Claim 1
Independent Claim 152 words
A method of producing a good quality flux source image of a microscopic feature located on a medium to assist with performing a light measurement of a dimension of said feature, said method comprising the steps of: receiving a video image of a user region of interest surrounding said feature to be measured; developing a light intensity distribution profile of a system region surrounding said feature; determining whether said developed light intensity distribution profile is of good quality; and wherein when it is determined that said developed light intensity distribution profile is not of good quality, performing the following, receiving a reference image corresponding to said video image of said user region of interest surrounding said feature, subtracting said reference image from said video image to produce a difference image, and storing said difference image as said flux source image for use in said light measurement of said dimension of said feature.
Claim 2
Independent Claim 152 words
A method of producing a good quality flux source image of a microscopic feature located on a medium to assist with performing a light measurement of a dimension of said feature, said method comprising the steps of: receiving a video image of a user region of interest surrounding said feature to be measured; developing a light intensity distribution profile of a system region surrounding said feature; determining whether said developed light intensity distribution profile is of good quality; and wherein when it is determined that said developed light intensity distribution profile is not of good quality, performing the following, receiving a reference image corresponding to said video image of said user region of interest surrounding said feature, subtracting said reference image from said video image to produce a difference image, and storing said difference image as said flux source image for use in said light measurement of said dimension of said feature.
Claim 3
Dependent Claim 24 words
A method as recited in claim 1 wherein said video image is received from a production inspection machine for inspecting features on a photomask.
Claim 4
Dependent Claim 34 words
A method as recited in claim 1 wherein said determining whether said developed light intensity distribution profile is of good quality includes: determining whether a baseline of said profile has a low standard deviation.
Claim 5
Dependent Claim 40 words
A method as recited in claim 1 further comprising: developing multiple system regions surrounding said feature; developing a light intensity distribution profile for each of said multiple system regions; and determining which of said profiles is of the best quality.
Claim 6
Dependent Claim 119 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of determining the amount of light flux from a microscopic defect located on said mask to assist with performing a measurement of a dimension of said defect, said method comprising: receiving an image of said defect to be measured; producing a plurality of system regions of interest surrounding said defect to be measured; developing a light intensity distribution profile for each of said system regions of interest; determining a total light flux measurement for each of said light intensity distribution profiles; and choosing one of said total light flux measurements as the best measurement of said amount of light flux from said microscopic defect.
Claim 7
Dependent Claim 119 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of determining the amount of light flux from a microscopic defect located on said mask to assist with performing a measurement of a dimension of said defect, said method comprising: receiving an image of said defect to be measured; producing a plurality of system regions of interest surrounding said defect to be measured; developing a light intensity distribution profile for each of said system regions of interest; determining a total light flux measurement for each of said light intensity distribution profiles; and choosing one of said total light flux measurements as the best measurement of said amount of light flux from said microscopic defect.
Claim 8
Dependent Claim 33 words
A mask as recited in claim 5 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 9
Dependent Claim 39 words
A mask as recited in claim 5 wherein said step of choosing one of said total light flux measurements as the best measurement includes the sub-step of: calculating a standard deviation for a baseline of each of said profiles.
Claim 10
Dependent Claim 46 words
A mask as recited in claim 5 wherein said plurality of system regions of interest includes a vertical region, a horizontal region, a first region angled at 45 degrees from said vertical region, and a second region angled at minus 45 degrees from said vertical region.
Claim 11
Dependent Claim 38 words
A mask as recited in claim 5 wherein each of said plurality of system regions of interest surrounding said defect to be measured has a size based at least in part upon a defect type of said feature.
Claim 12
Dependent Claim 41 words
A mask as recited in claim 5 wherein said step of determining a total light flux measurement includes the sub-step of: determining a baseline for each of said profile and subtracting said baseline from the profile from which it was determined.
Claim 13
Dependent Claim 97 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of determining the amount of light flux from a microscopic line located on said mask to assist with performing a measurement of a width of said line, said method comprising: receiving an image of said line to be measured; producing a system region of interest surrounding a portion of said line to be measured; determining a total light flux measurement associated with said system region of interest, whereby said total light flux measurement is useful in measuring the width of said line.
Claim 14
Dependent Claim 97 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of determining the amount of light flux from a microscopic line located on said mask to assist with performing a measurement of a width of said line, said method comprising: receiving an image of said line to be measured; producing a system region of interest surrounding a portion of said line to be measured; determining a total light flux measurement associated with said system region of interest, whereby said total light flux measurement is useful in measuring the width of said line.
Claim 15
Dependent Claim 33 words
A mask as recited in claim 11 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 16
Dependent Claim 52 words
A mask as recited in claim 11 wherein said step of producing produces a plurality of system regions of interest surrounding said portion of said line to be measured, and wherein said plurality of system regions of interest include two parallel regions, whereby an angle of said line may be compensated for.
Claim 17
Dependent Claim 45 words
A mask as recited in claim 11 wherein said step of determining a light flux measurement includes the sub-steps of: developing a light intensity distribution profile for said system region of interest; and determining a baseline for said profile and subtracting said baseline from profile.
Claim 18
Dependent Claim 45 words
A mask as recited in claim 11 further comprising: calculating an area for a portion of said line using said determined light flux; and determining a line width of said line by dividing said calculated area by a dimension of said system region of interest.
Claim 19
Dependent Claim 94 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of measuring the line width of a microscopic line located on said mask comprising: receiving an image of said line to be measured; producing a system region of interest surrounding said line to be measured; developing a light intensity distribution profile for said system region of interest surrounding said line to be measured; determining a total light flux measurement for said light intensity distribution profile; determining said line width of said line using said determined total light flux measurement.
Claim 20
Dependent Claim 94 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of measuring the line width of a microscopic line located on said mask comprising: receiving an image of said line to be measured; producing a system region of interest surrounding said line to be measured; developing a light intensity distribution profile for said system region of interest surrounding said line to be measured; determining a total light flux measurement for said light intensity distribution profile; determining said line width of said line using said determined total light flux measurement.
Claim 21
Dependent Claim 57 words
A mask as recited in claim 16 further comprising the steps of: producing two system regions of interest surrounding said line; averaging a total light flux measurement for each region to obtain said total light flux measurement; and computing a rotation correction based upon said two system regions of interest to adjust said total light flux measurement.
Claim 22
Dependent Claim 37 words
A mask as recited in claim 16 wherein said step of determining a total light flux measurement includes the sub-steps of: determining a baseline for said light intensity distribution profile; and subtracting said baseline from said profile.
Claim 23
Dependent Claim 24 words
A mask as recited in claim 5 wherein said dimension to be measured is less than about twice the wavelength used for said measurement.
Claim 24
Dependent Claim 29 words
A mask as recited in claim 11 further comprising: developing a reference image corresponding to said system region of interest for assisting in determining said total light flux measurement.
Claim 25
Dependent Claim 24 words
A mask as recited in claim 11 wherein said width to be measured is less than about twice the wavelength used for said measurement.
Claim 26
Dependent Claim 33 words
A mask as recited in claim 16 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 27
Dependent Claim 25 words
A mask as recited in claim 16 wherein said line width to be measured is less than about twice the wavelength used for said measurement.
Claim 28
Dependent Claim 78 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of measuring a dimension of a feature located on said mask, said method comprising: receiving an image of said feature to be measured, the dimension of said feature to be measured having a size of less than about twice the wavelength used for said measurement; determining a flux value corresponding to said feature; determining said dimension of said feature using said flux value.
Claim 29
Dependent Claim 78 words
A mask used in the manufacture of semiconductor devices, said mask resulting from a method of measuring a dimension of a feature located on said mask, said method comprising: receiving an image of said feature to be measured, the dimension of said feature to be measured having a size of less than about twice the wavelength used for said measurement; determining a flux value corresponding to said feature; determining said dimension of said feature using said flux value.
Claim 30
Dependent Claim 27 words
A mask as recited in claim 24 further comprising: developing an intensity profile of said feature to be measured, said profile useful for determining said flux value.
Claim 31
Dependent Claim 20 words
A mask as recited in claim 24 further comprising: correcting for said dimension by referring to a non-linear calibration curve.
Claim 32
Dependent Claim 22 words
A mask as recited in claim 11 further comprising: determining a line width of said line using said determined light flux measurement.
Claim 33
Dependent Claim 114 words
A semiconductor device, said semiconductor device resulting from a method of determining the amount of light flux from a microscopic defect located on a mask to assist with performing a measurement of a dimension of said defect, said method comprising: receiving an image of said defect to be measured; producing a plurality of system regions of interest surrounding said defect to be measured; developing a light intensity distribution profile for each of said system regions of interest; determining a total light flux measurement for each of said light intensity distribution profiles; and choosing one of said total light flux measurements as the best measurement of said amount of light flux from said microscopic defect.
Claim 34
Dependent Claim 114 words
A semiconductor device, said semiconductor device resulting from a method of determining the amount of light flux from a microscopic defect located on a mask to assist with performing a measurement of a dimension of said defect, said method comprising: receiving an image of said defect to be measured; producing a plurality of system regions of interest surrounding said defect to be measured; developing a light intensity distribution profile for each of said system regions of interest; determining a total light flux measurement for each of said light intensity distribution profiles; and choosing one of said total light flux measurements as the best measurement of said amount of light flux from said microscopic defect.
Claim 35
Dependent Claim 34 words
A semiconductor device as recited in claim 28 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 36
Dependent Claim 40 words
A semiconductor device as recited in claim 28 wherein said step of choosing one of said total light flux measurements as the best measurement includes the sub-step of: calculating a standard deviation for a baseline of each of said profiles.
Claim 37
Dependent Claim 47 words
A semiconductor device as recited in claim 28 wherein said plurality of system regions of interest includes a vertical region, a horizontal region, a first region angled at 45 degrees from said vertical region, and a second region angled at minus 45 degrees from said vertical region.
Claim 38
Dependent Claim 39 words
A semiconductor device as recited in claim 28 wherein each of said plurality of system regions of interest surrounding said defect to be measured has a size based at least in part upon a defect type of said feature.
Claim 39
Dependent Claim 42 words
A semiconductor device as recited in claim 28 wherein said step of determining a total light flux measurement includes the sub-step of: determining a baseline for each of said profile and subtracting said baseline from the profile from which it was determined.
Claim 40
Dependent Claim 92 words
A semiconductor device, said semiconductor device resulting from a method of determining the amount of light flux from a microscopic line located on a mask to assist with performing a measurement of a width of said line, said method comprising: receiving an image of said line to be measured; producing a system region of interest surrounding a portion of said line to be measured; determining a total light flux measurement associated with said system region of interest, whereby said total light flux measurement is useful in measuring the width of said line.
Claim 41
Dependent Claim 92 words
A semiconductor device, said semiconductor device resulting from a method of determining the amount of light flux from a microscopic line located on a mask to assist with performing a measurement of a width of said line, said method comprising: receiving an image of said line to be measured; producing a system region of interest surrounding a portion of said line to be measured; determining a total light flux measurement associated with said system region of interest, whereby said total light flux measurement is useful in measuring the width of said line.
Claim 42
Dependent Claim 34 words
A semiconductor device as recited in claim 34 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 43
Dependent Claim 53 words
A semiconductor device as recited in claim 34 wherein said step of producing produces a plurality of system regions of interest surrounding said portion of said line to be measured, and wherein said plurality of system regions of interest include two parallel regions, whereby an angle of said line may be compensated for.
Claim 44
Dependent Claim 46 words
A semiconductor device as recited in claim 34 wherein said step of determining a light flux measurement includes the sub-steps of: developing a light intensity distribution profile for said system region of interest; and determining a baseline for said profile and subtracting said baseline from profile.
Claim 45
Dependent Claim 46 words
A semiconductor device as recited in claim 34 further comprising: calculating an area for a portion of said line using said determined light flux; and determining a line width of said line by dividing said calculated area by a dimension of said system region of interest.
Claim 46
Dependent Claim 89 words
A semiconductor device, said semiconductor device resulting from a method of measuring the line width of a microscopic line located on a mask comprising: receiving an image of said line to be measured; producing a system region of interest surrounding said line to be measured; developing a light intensity distribution profile for said system region of interest surrounding said line to be measured; determining a total light flux measurement for said light intensity distribution profile; determining said line width of said line using said determined total light flux measurement.
Claim 47
Dependent Claim 89 words
A semiconductor device, said semiconductor device resulting from a method of measuring the line width of a microscopic line located on a mask comprising: receiving an image of said line to be measured; producing a system region of interest surrounding said line to be measured; developing a light intensity distribution profile for said system region of interest surrounding said line to be measured; determining a total light flux measurement for said light intensity distribution profile; determining said line width of said line using said determined total light flux measurement.
Claim 48
Dependent Claim 58 words
A semiconductor device as recited in claim 39 further comprising the steps of: producing two system regions of interest surrounding said line; averaging a total light flux measurement for each region to obtain said total light flux measurement; and computing a rotation correction based upon said two system regions of interest to adjust said total light flux measurement.
Claim 49
Dependent Claim 38 words
A semiconductor device as recited in claim 39 wherein said step of determining a total light flux measurement includes the sub-steps of: determining a baseline for said light intensity distribution profile; and subtracting said baseline from said profile.
Claim 50
Dependent Claim 25 words
A semiconductor device as recited in claim 28 wherein said dimension to be measured is less than about twice the wavelength used for said measurement.
Claim 51
Dependent Claim 30 words
A semiconductor device as recited in claim 34 further comprising: developing a reference image corresponding to said system region of interest for assisting in determining said total light flux measurement.
Claim 52
Dependent Claim 25 words
A semiconductor device as recited in claim 34 wherein said width to be measured is less than about twice the wavelength used for said measurement.
Claim 53
Dependent Claim 34 words
A semiconductor device as recited in claim 39 wherein said image is received from a production inspection machine and wherein said method is performed with said mask in place in said production inspection machine.
Claim 54
Dependent Claim 26 words
A semiconductor device as recited in claim 39 wherein said line width to be measured is less than about twice the wavelength used for said measurement.
Claim 55
Dependent Claim 73 words
A semiconductor device, said semiconductor device resulting from a method of measuring a dimension of a feature located on a mask, said method comprising: receiving an image of said feature to be measured, the dimension of said feature to be measured having a size of less than about twice the wavelength used for said measurement; determining a flux value corresponding to said feature; determining said dimension of said feature using said flux value.
Claim 56
Dependent Claim 73 words
A semiconductor device, said semiconductor device resulting from a method of measuring a dimension of a feature located on a mask, said method comprising: receiving an image of said feature to be measured, the dimension of said feature to be measured having a size of less than about twice the wavelength used for said measurement; determining a flux value corresponding to said feature; determining said dimension of said feature using said flux value.
Claim 57
Dependent Claim 28 words
A semiconductor device as recited in claim 47 further comprising: developing an intensity profile of said feature to be measured, said profile useful for determining said flux value.
Claim 58
Dependent Claim 21 words
A semiconductor device as recited in claim 47 further comprising: correcting for said dimension by referring to a non-linear calibration curve.
Claim 59
Dependent Claim 23 words
A semiconductor device as recited in claim 34 further comprising: determining a line width of said line using said determined light flux measurement.
Claim 60
Dependent Claim 24 words
A method as recited in claim 1 wherein said dimension to be measured is less than about twice the wavelength used for said measurement.

References Cited (Backward Citations)

US5614990A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2003-12-26 2004-06-26 2004-12-26 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2007-12-26 2008-06-26 2008-12-26 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2011-12-26 2012-06-26 2012-12-26 $7700.00 Window Closed / Lapsed

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