US6067154A
Expired / Lapsed
US
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Method and apparatus for the molecular identification of defects in semiconductor manufacturing using a radiation scattering technique such as raman spectroscopy
Assignee: Advanced Micro Devices Inc
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Filing: 1998-10-23
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Granted: 2000-05-23
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Expires: 2018-10-23
Abstract
Abstract A method and apparatus are provided for obtaining molecular information about materials at a selected site on or in a semiconductor topography. In a preferred embodiment, the selected site is a defect from a defect map generated by an automated wafer inspection system. A sample stage and drive/alignment system are used to move the semiconductor topography such that a selected defect is aligned with the illumination provided by a radiation scattering measurement system. A Raman spectroscopy system may be used for the radiation scattering measurement. The intensity and frequency of inelastically scattered radiation from the vicinity of the selected defect is compared to standard spectra to determine the chemical composition and material phase of the region analyzed. The depth into the topography probed may be adjusted by changing the wavelength of radiation used in the Raman spectroscopy measurement. In this way, the source of a particular defect, even if buried in the topography during the semiconductor fabrication process, may be determined. Knowledge of the fabrication process guides selection of the appropriate depths to be analyzed.
Inventors
- 👤 Tim Z. Hossain
- 👤 Charles E. May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:27
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/62; G01N21/63; G01N21/65; G01N2021/653; G01N2021/656
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
154 words
A method for obtaining identification of a molecular composition of material at a selected site within a semiconductor topography, comprising: determining intended compositions and thicknesses of underlying layers fabricated below the selected site, wherein the determining is accomplished using knowledge of a preceding semiconductor fabrication process performed upon the semiconductor topography; selecting an analysis depth above which material in the topography is to be identified wherein the analysis depth is consistent with said compositions and thicknesses; setting a frequency of a monochromatic radiation source such that a penetration depth of radiation from the radiation source into the topography corresponds to the analysis depth; illuminating the selected site with radiation from the monochromatic radiation source; detecting intensities and frequency shifts of radiation scattered from an illuminated region of the topography; and comparing the detected intensities and frequency shifts to standard spectra to obtain identification of the molecular composition of the material within the illuminated region.
Claim 2
Independent Claim
154 words
A method for obtaining identification of a molecular composition of material at a selected site within a semiconductor topography, comprising: determining intended compositions and thicknesses of underlying layers fabricated below the selected site, wherein the determining is accomplished using knowledge of a preceding semiconductor fabrication process performed upon the semiconductor topography; selecting an analysis depth above which material in the topography is to be identified wherein the analysis depth is consistent with said compositions and thicknesses; setting a frequency of a monochromatic radiation source such that a penetration depth of radiation from the radiation source into the topography corresponds to the analysis depth; illuminating the selected site with radiation from the monochromatic radiation source; detecting intensities and frequency shifts of radiation scattered from an illuminated region of the topography; and comparing the detected intensities and frequency shifts to standard spectra to obtain identification of the molecular composition of the material within the illuminated region.
Claim 3
Dependent Claim
49 words
The method as recited in claim 1, wherein said illuminating the selected site further comprises loading the semiconductor topography into a sample stage; and moving the sample stage in a horizontal plane to align the semiconductor topography such that the selected site is illuminated by the monochromatic radiation source.
Claim 4
Dependent Claim
20 words
The method as recited in claim 2, wherein said moving further comprises establishing an alignment reference for the sample stage.
Claim 5
Dependent Claim
58 words
The method as recited in claim 3, wherein said establishing comprises: determining x-y coordinates for a center of the topography, wherein the x-y coordinates lie in a horizontal plane; determining x-y coordinates for a feature cut into an edge of the topography; and assigning x-y coordinates for the semiconductor topography using the center and the feature for reference.
Claim 6
Dependent Claim
22 words
The method as recited in claim 4, wherein said determining x-y coordinates for a feature comprises determining x-y coordinates for a notch.
Claim 7
Dependent Claim
26 words
The method as recited in claim 4, wherein said determining x-y coordinates for a feature comprises determining x-y coordinates for a center point of a flat.
Claim 8
Dependent Claim
28 words
The method as recited in claim 4, wherein said determining x-y coordinates for a center and determining x-y coordinates for a feature comprise using a laser reflection technique.
Claim 9
Dependent Claim
175 words
The method as recited in claim 4, wherein said determining x-y coordinates for a center comprises: positioning an alignment laser and an alignment photodetector above the topography such that radiation from the alignment laser is reflected by the topography and detected by the alignment photodetector; determining a width of the topography in an x direction by moving the sample stage along positive and negative x directions until the radiation detected by the alignment photodetector abruptly decreases; determining a y-direction reference position by moving the sample stage in increments along positive and negative y directions and determining the width of the topography in the x direction for each increment, until a maximum width is obtained; determining an x-direction reference position by moving the sample stage in increments along positive and negative x directions and determining the width of the topography in the y direction for each increment, until a maximum width is obtained; and setting the x-direction and y-direction reference positions to coordinates (0,0), wherein coordinates (0,0) comprise approximate coordinates for the center of the topography.
Claim 10
Dependent Claim
38 words
The method as recited in claim 4, wherein said determining x-y coordinates for a feature comprises rotating the topography about coordinates (0,0) and determining the width of the topography for each increment, until a minimum width is obtained.
Claim 11
Dependent Claim
16 words
The method as recited in claim 1, wherein said detecting comprises performing a Raman spectroscopy measurement.
Claim 12
Dependent Claim
84 words
The method as recited in claim 1, further comprising: importing a file comprising a defect map of the topography produced by a wafer inspection system into a computer system; choosing the selected site from among defects in the defect map, prior to said illuminating; recording intensity versus frequency shift of the radiation scattered from the illuminated region of the topography, subsequent to said detecting; and comparing the intensity versus frequency shift with standard spectra to determine molecular compositions of materials in the illuminated region.
Claim 13
Dependent Claim
54 words
The method as recited in claim 11, wherein said illuminating further comprises: loading the semiconductor topography onto a sample stage; establishing an alignment reference for the sample stage; and moving the sample stage in a horizontal plane to align the semiconductor topography such that the selected site is illuminated by the monochromatic radiation source.
Claim 14
Dependent Claim
76 words
The method as recited in claim 12, wherein said establishing comprises: determining x-y coordinates for a center of the topography, wherein the x-y coordinates lie in a horizontal plane; determining x-y coordinates for a feature cut into an edge of the topography; assigning x-y coordinates for the semiconductor topography using the center and the feature as a reference; and performing an offset adjustment for matching the x-y coordinates with coordinates used by the defect map file.
Claim 15
Dependent Claim
28 words
The method as recited in claim 13, wherein said determining x-y coordinates for a center and determining x-y coordinates for a feature comprise using a laser reflection technique.
Claim 16
Dependent Claim
16 words
The method as recited in claim 13, wherein said detecting comprises performing a Raman spectroscopy measurement.
References Cited (Backward Citations)
US4978862A
Cited
US5208648A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-05-23 | 2003-11-22 | 2004-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-23 | 2007-11-22 | 2008-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-23 | 2011-11-22 | 2012-05-23 | $7700.00 | Window Closed / Lapsed |