US5631733A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Large area defect monitor tool for manufacture of clean surfaces
Assignee: Photon Dynamics Inc
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Filing: 1995-01-20
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Granted: 1997-05-20
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Expires: 2015-01-20
Abstract
Abstract A method and resulting system for directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to the SUS and for observing the scattered nonspecular energy in one of a plurality of fractional windows of a viewed image of the SUS via a plurality of focussing elements. Such arrangement results in simultaneous and significant throughput and sensitivity enhancement over existing art. The method can be enhanced further wherein the observing step is performed through suitable relative motion of the scattering image over the imaging plane to permit over sampling. Furthermore, the DMT is significantly simplified because imaging is utilized to electronically scan the wafer instead of using opto-mechanical scanning means. Imaging sensors with an aggregate 2000×2000 pixel resolution could image a 200 mm wafer to 100 microns pitch.
Inventors
- 👤 Francois J. Henley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:51
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N21/8806; G01N21/94
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
147 words
A method for observing defects on a surface by means of optically scattered energy, the method comprising: directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and observing said scattered nonspecular energy in one of a plurality of fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement; wherein said observing and directing steps occur simultaneously and are performed substantially without any relative motion between said SUS and said symmetrical detection arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 2
Independent Claim
147 words
A method for observing defects on a surface by means of optically scattered energy, the method comprising: directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and observing said scattered nonspecular energy in one of a plurality of fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement; wherein said observing and directing steps occur simultaneously and are performed substantially without any relative motion between said SUS and said symmetrical detection arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 3
Dependent Claim
20 words
The method according to claim 1 wherein said symmetrical detection arrangement and said symmetrical array arrangement are of Cartesian symmetry.
Claim 4
Dependent Claim
20 words
The method according to claim 1 wherein said symmetrical detection arrangement and said symmetrical array arrangement are of Polar symmetry.
Claim 5
Dependent Claim
19 words
The method according to claim 1 wherein said focal plane is in an imaging array of an electronic camera.
Claim 6
Dependent Claim
27 words
The method according to claim 1 wherein said focal plane is an imaging surface, said imaging surface being operative to convert said nonspecular energy into detectable energy.
Claim 7
Dependent Claim
24 words
The method according to claim 1 wherein each of said focusing elements is a high-quality lens having an f-number of about f/1.5 and less.
Claim 8
Dependent Claim
26 words
The method according to claim 1 wherein each of said focusing elements comprises a high-quality lens operative at an effective object f-number of less than f/20.
Claim 9
Dependent Claim
32 words
The method according to claim 7 wherein each of said focussing elements is operative at an effective object f-number of less than f/9, said refractor having a of than f/1.5 and f/0.9.
Claim 10
Dependent Claim
17 words
The method according to claim 1 wherein said source emits in narrow wavelength range of noncoherent light.
Claim 11
Dependent Claim
15 words
The method according to claim 1 wherein said collimated illumination is spectrally filtered noncoherent light.
Claim 12
Dependent Claim
13 words
The method according to claim 1 wherein said collimated illumination is coherent light.
Claim 13
Dependent Claim
30 words
The method according to claim 1 to 11 wherein said observing step is performed without relative motion between-said symmetrical detection arrangement and said symmetrical array arrangement to permit over sampling.
Claim 14
Dependent Claim
29 words
The method according to claim 1 to 11 wherein said observing step is performed without relative motion between said SUS and said symmetrical array arrangement to permit over sampling.
Claim 15
Dependent Claim
14 words
The method of claim 1 is provided in a cluster tool semiconductor processing system.
Claim 16
Dependent Claim
18 words
The method of claim 1 wherein said observing step is provided on an x-y stage to provide over-sampling.
Claim 17
Independent Claim
146 words
A system for observing defects on a surface by means of optically scattered energy, the system comprising: means for directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and means for observing said scattered nonspecular energy in one of a plurality fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement, said SUS and said symmetrical array arrangement having substantially no relative motion between said SUS and said symmetrically array arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 18
Independent Claim
146 words
A system for observing defects on a surface by means of optically scattered energy, the system comprising: means for directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and means for observing said scattered nonspecular energy in one of a plurality fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement, said SUS and said symmetrical array arrangement having substantially no relative motion between said SUS and said symmetrically array arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 19
Dependent Claim
20 words
The system according to claim 16 wherein said symmetrical detection arrangement and said symmetrical array arrangement are of Cartesian symmetry.
Claim 20
Dependent Claim
20 words
The system according to claim 16 wherein said symmetrical detection arrangement and said symmetrical array arrangement are of Polar symmetry.
Claim 21
Dependent Claim
19 words
The system according to claim 16 wherein said focal plane is in an imaging array of an electronic camera.
Claim 22
Dependent Claim
27 words
The system according to claim 16 wherein said focal plane is an imaging surface, said imaging surface being operative to convert said nonspecular energy into detectable energy.
Claim 23
Dependent Claim
24 words
The system according to claim 16 wherein each of said focusing elements is a high-quality lens having an f-number of about f/1.5 and less.
Claim 24
Dependent Claim
26 words
The system according to claim 16 wherein each of said focusing elements comprises a high-quality lens operative at an effective object f-number of less than f/20.
Claim 25
Dependent Claim
37 words
The system according to claim 22 wherein each of said focussing elements is operative at an effective object f-number of less than f/9, said refractor having a minimum f-number of smaller than f/1.5 and greater than f/0.9.
Claim 26
Dependent Claim
17 words
The system according to claim 16 wherein said source emits in narrow wavelength range of noncoherent light.
Claim 27
Dependent Claim
15 words
The system according to claim 16 wherein said collimated illumination is spectrally filtered noncoherent light.
Claim 28
Dependent Claim
13 words
The system according to claim 16 wherein said collimated illumination is coherent light.
Claim 29
Dependent Claim
17 words
The system according to claim 16 is provided in communication with a cluster tool semiconductor processing system.
Claim 30
Dependent Claim
19 words
The system of claim 16 wherein said means for observing is provided on an x-y stage to provide over-sampling.
Claim 31
Independent Claim
158 words
A method for manufacturing a semiconductor integrated circuit, said method comprising steps of observing defects on a wafer surface by means of optically scattered energy, the method comprising: directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and observing said scattered nonspecular energy in one of a plurality of fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement; wherein said observing and directing steps occur simultaneously and are performed substantially without any relative motion between said SUS and said symmetrical detection arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 32
Independent Claim
158 words
A method for manufacturing a semiconductor integrated circuit, said method comprising steps of observing defects on a wafer surface by means of optically scattered energy, the method comprising: directing generally collimated illumination from a source at an oblique angle to a surface under inspection (SUS) to produce scattered nonspecular energy substantially normal to said SUS; and observing said scattered nonspecular energy in one of a plurality of fractional windows of a viewed image of the SUS via a plurality of focussing elements at a plurality of remote focal planes having a symmetrical detection arrangement, said focal planes being mounted adjacent one another arranged in a symmetrical array arrangement adjacent one another, said symmetrical detection arrangement corresponding to said symmetrical array arrangement; wherein said observing and directing steps occur simultaneously and are performed substantially without any relative motion between said SUS and said symmetrical detection arrangement to substantially reduce a possibility of any scanning noise and light source fluctuations.
Claim 33
Dependent Claim
15 words
The method of claim 29 wherein said observing step is provided on an x-y stage.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-19 | 2000-11-18 | 2001-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-19 | 2004-11-18 | 2005-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-19 | 2008-11-18 | 2009-05-20 | $7700.00 | Window Closed / Lapsed |