Patent US5032734A successfully refreshed from Google Patents.
US5032734A
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Method and apparatus for nondestructively measuring micro defects in materials
Assignee: VTI Inc A CORP OF OHIO
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Filing: 1990-10-15
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Granted: 1991-07-16
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Expires: 2010-10-15
Abstract
Abstract A method and apparatus are disclosed for nondestructively measuring the density and orientation of crystalline and other micro defects on and directly below the surface of a properly prepared material such as a semiconductor wafer. The material surface is illuminated with a probe beam of electromagnetic radiation which is limited to a nondestructive power level or levels. Polarization and wavelength or wavelengths of the electromagnetic radiation are selected according to certain characteristics of the material so that penetration depth is controlled. Specific orientation of the material with respect to the probe beam and the detector is required to detect that portion of the probe beam scattered from the defects of interest, surface or subsurface, without interference from other scatter sources and to identify the orientation of the defects. Maps of scatter intensity versus position are made according to the density of the defects encountered.
Inventors
- 👤 Fred D. Orazio, Jr.
- 👤 Robert B. Sledge, Jr.
- 👤 Robert M. Silva, deceased
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:57
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/21; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N2021/178; G01N2021/1782; G01N21/8806; G01N2021/8845; G01N21/8851; G01N2021/8854; G01N2021/8861; G01N2021/8864; G01N21/25; G01N21/31; G01N21/33; G01N21/47; G01N21/9505
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
323 words
A method of simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation with substantially equal S and P polarized components; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 2
Independent Claim
323 words
A method of simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation with substantially equal S and P polarized components; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 3
Independent Claim
318 words
A method of simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation with elliptical polarization; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 4
Independent Claim
318 words
A method of simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation with elliptical polarization; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 5
Independent Claim
249 words
A method of measuring the distribution of subsurface micro defects caused by random processes such as ion implantation, on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the line of sight of the detector toward the surface of the material to the point where the beam intercepts the surface; (d) limiting the extent of the scattered electromagnetic radiation entering the detector in order to detect the scatter coming from a small solid angle around the line of sight, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of the selected minimum scatter for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected minimum scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
Claim 6
Independent Claim
249 words
A method of measuring the distribution of subsurface micro defects caused by random processes such as ion implantation, on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation; (b) directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) directing the line of sight of the detector toward the surface of the material to the point where the beam intercepts the surface; (d) limiting the extent of the scattered electromagnetic radiation entering the detector in order to detect the scatter coming from a small solid angle around the line of sight, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of the selected minimum scatter for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected minimum scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
Claim 7
Dependent Claim
338 words
Apparatus for simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) means for generating a beam of electromagnetic radiation with substantially equal S and P polarized components; (b) means for directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) means for directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) means for limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) means for producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) means for producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) means for repeatably engaging means (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mean for mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 8
Dependent Claim
338 words
Apparatus for simultaneously measuring the distribution of surface and subsurface micro defects on a predetermined area of a material, comprising the steps of: (a) means for generating a beam of electromagnetic radiation with substantially equal S and P polarized components; (b) means for directing the beam towards the surface at a predetermined fixed angle of incidence and focusing the beam to expose a small portion of the material to the electromagnetic radiation; (c) means for directing the lines of sight of two detectors toward the surface of the material to the point where the beam intercepts the surface, one line of sight and detector for only P polarized electromagnetic radiation and the other line of sight and detector for only S polarized electromagnetic radiation; (d) means for limiting the extent of the scattered electromagnetic radiation entering each detector in order to detect the scatter coming from a small solid angle around the line of sight of each detector, for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal proportional to the detected intensity from each detector; (e) means for producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational positions of selected scatter signature for that point; (f) means for producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) means for repeatably engaging means (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mean for mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area, the scatter intensity sensed at the P polarization detector being related to the subsurface defects and the scatter intensity sensed at the S polarization detector being related to the surface defects and the rotational positions being related to the defect orientations.
Claim 9
Independent Claim
190 words
A method of measuring the distribution of micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation; (b) directing the beam towards the surface at a predetermined fixed angle of incidence; (c) directing a detector's line of sight toward the surface of the material to the point where the beam intercepts the surface; (d) detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal related to the detected intensity; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of selected scatter for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
Claim 10
Independent Claim
190 words
A method of measuring the distribution of micro defects on a predetermined area of a material, comprising the steps of: (a) generating a beam of electromagnetic radiation; (b) directing the beam towards the surface at a predetermined fixed angle of incidence; (c) directing a detector's line of sight toward the surface of the material to the point where the beam intercepts the surface; (d) detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal related to the detected intensity; (e) producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of selected scatter for that point; (f) producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) repeating above steps (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
Claim 11
Dependent Claim
205 words
Apparatus for measuring the distribution of micro defects on a predetermined area of a material, comprising the steps of: (a) means for generating a beam of electromagnetic radiation; (b) means for directing the beam towards the surface at a predetermined fixed angle of incidence; (c) means for directing a detector's line of sight toward the surface of the material to the point where the beam intercepts the surface; (d) means for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal related to the detected intensity; (e) means for producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of selected scatter for that point; (f) means for producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) means for repeatably engaging means (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) means for mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
Claim 12
Dependent Claim
205 words
Apparatus for measuring the distribution of micro defects on a predetermined area of a material, comprising the steps of: (a) means for generating a beam of electromagnetic radiation; (b) means for directing the beam towards the surface at a predetermined fixed angle of incidence; (c) means for directing a detector's line of sight toward the surface of the material to the point where the beam intercepts the surface; (d) means for detecting a portion of the scattered electromagnetic radiation and converting it to an electrical signal related to the detected intensity; (e) means for producing relative rotation between the beam and the material about an axis substantially perpendicular to the surface and at the point where the beam intercepts the surface and determining the rotational position of selected scatter for that point; (f) means for producing relative lateral movement between the beam and the material to expose an adjacent portion of the material to the electromagnetic radiation; (g) means for repeatably engaging means (e) and (f) for each portion of the material exposed until the predetermined area is covered in a contiguous manner; and (h) means for mapping the selected scatter intensity versus the coordinate position of each point of measurement for the predetermined area.
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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) | 1994-07-15 | 1995-01-14 | 1995-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-07-15 | 1999-01-14 | 1999-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-07-15 | 2003-01-14 | 2003-07-16 | $7700.00 | Window Closed / Lapsed |