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US5486919A Expired / Lapsed US ⏱️ 0.0 years remaining

Inspection method and apparatus for inspecting a particle, if any, on a substrate having a pattern

Assignee: Canon Inc
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Filing: 1993-06-15
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Granted: 1996-01-23
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Expires: 2013-06-15
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Abstract

Abstract Disclosed is an inspection method and apparatus: wherein (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength are produced; at least the first light is projected to a position of inspection; and heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization, is detected.

Inventors

  • 👤 Toshihiko Tsuji
  • 👤 Seiji Takeuchi
  • 👤 Kyoichi Miyazaki
  • 👤 Minoru Yoshii
  • 👤 Noriyuki Nose
  • 👤 Tetsuzo Mori

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 03:40
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/70605; G03F7/70616; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/94; G03F7/7065; G03F7/708; G03F7/70908; G03F7/70916; G01J; G01J9/00; G01J9/02; G01J2009/0261; G01J9/04; G01N21/17; G01N21/47; G01N2021/4792; G01N21/8806

Claims Analysis

Total Claims: 32
Claim 1
Independent Claim 140 words
An inspection apparatus for inspecting a particle, if any, on a substrate having a pattern, said apparatus comprising: light producing means for producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength; light projecting means for projecting at least the first light to a position of inspection upon the substrate; detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization; and inspecting means for inspecting a particle, if any, on the substrate on the basis of an output of said detecting means.
Claim 2
Dependent Claim 140 words
An inspection apparatus for inspecting a particle, if any, on a substrate having a pattern, said apparatus comprising: light producing means for producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength; light projecting means for projecting at least the first light to a position of inspection upon the substrate; detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization; and inspecting means for inspecting a particle, if any, on the substrate on the basis of an output of said detecting means.
Claim 3
Dependent Claim 30 words
An inspection apparatus according to claim 1, wherein said light projecting means comprises scanning means for deflecting at least the first light to optically scan a surface to be inspected.
Claim 4
Dependent Claim 27 words
An apparatus according to claim 2, further comprising a lens system for imaging a scanning area of the surface upon a detection surface of said detecting means.
Claim 5
Dependent Claim 21 words
An apparatus according to claim 1, wherein the second light is projected at the same position irradiated with the first light.
Claim 6
Dependent Claim 39 words
An apparatus according to claim 1, wherein the second light is not projected on the surface to be inspected and wherein the second light and scattered light resulting from the first light are caused to interfere with each other.
Claim 7
Dependent Claim 22 words
An apparatus according to claim 1, wherein said light producing means produces the first light and second light in a combined flux.
Claim 8
Dependent Claim 20 words
An apparatus according to claim 1, wherein said light producing means produces the first light and the second light separately.
Claim 9
Dependent Claim 34 words
An apparatus according to claim 1, wherein the first light comprises linearly polarized light of a predetermined direction while the second light comprises linearly polarized light of another direction different from the predetermined direction.
Claim 10
Dependent Claim 21 words
An apparatus according to claim 1, wherein at least one of the first light and second light comprises circularly polarized light.
Claim 11
Dependent Claim 38 words
An apparatus according to claim 1, wherein said detecting means detects interference light produced on the basis of the second light and light advancing in a particular direction sideways to the direction of incidence of the first light.
Claim 12
Dependent Claim 19 words
An apparatus according to claim 10, wherein the particular direction has an angle in a range of 90-180 deg.
Claim 13
Dependent Claim 21 words
An apparatus according to claim 1, further comprising a setting mechanism for setting the state of polarization of the first light.
Claim 14
Dependent Claim 21 words
An apparatus according to claim 1, further comprising a setting mechanism for setting the state of polarization of the second light.
Claim 15
Dependent Claim 49 words
An apparatus according to claim 1, further comprising inspecting means comprising signal processing means including a phase synchronization loop circuit, wherein said inspecting means inspects the state of the inspection position on the basis of processing, through said signal processing means, a beat signal of the detected interference light.
Claim 16
Dependent Claim 63 words
An apparatus according to claim 1, further comprising (i) oscillating means for producing a high frequency signal of a frequency different from a beat signal of the detected interference light, (ii) multiplying means for multiplying the beat signal and the high frequency signal, and (iii) inspecting means for inspecting the state of the inspection position on the basis of the result of multiplication.
Claim 17
Dependent Claim 38 words
A transfer system, comprising: an inspection apparatus as recited in claim 1, for inspecting an original having a pattern; and a transfer apparatus for transferring onto a substrate the pattern of the original inspected by said inspection apparatus.
Claim 18
Dependent Claim 32 words
An original cleaning and inspecting system, comprising: a cleaning apparatus for cleaning an original; and an inspection apparatus as recited in claim 1, for inspecting the original cleaned by said cleaning apparatus.
Claim 19
Dependent Claim 41 words
An apparatus according to claim 1, wherein the inspection position lies on a mask having a pattern to be transferred, and wherein a particle if any on the mask can be inspected while being distinguished from the pattern of the mask.
Claim 20
Dependent Claim 136 words
An inspection apparatus, comprising: first light producing means for producing first light having a first wavelength, and second light having a second wavelength, different from the first wavelength; second light producing means for producing third light having a third wavelength, and fourth light having a fourth wavelength, different from the third wavelength; light projecting means for projecting at least the first light and the third light to a position of inspection; first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position as a result of irradiation by the first light; and second detecting means for detecting heterodyne interference light produced on the basis of the fourth light and light scattered at the inspection position as a result of irradiation by the third light.
Claim 21
Dependent Claim 136 words
An inspection apparatus, comprising: first light producing means for producing first light having a first wavelength, and second light having a second wavelength, different from the first wavelength; second light producing means for producing third light having a third wavelength, and fourth light having a fourth wavelength, different from the third wavelength; light projecting means for projecting at least the first light and the third light to a position of inspection; first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position as a result of irradiation by the first light; and second detecting means for detecting heterodyne interference light produced on the basis of the fourth light and light scattered at the inspection position as a result of irradiation by the third light.
Claim 22
Dependent Claim 33 words
An apparatus according to claim 19, wherein the first light and the second light have different states of polarization, and wherein the third light and the fourth light have different states of polarization.
Claim 23
Dependent Claim 41 words
An apparatus according to claim 19, wherein the inspection position lies on a mask having a pattern to be transferred, and wherein a particle if any on the mask can be inspected while being distinguished from the pattern of the mask.
Claim 24
Dependent Claim 181 words
An inspection apparatus for inspecting a particle, if any, on a substrate having a pattern, said apparatus comprising: light producing means for producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization and a second wavelength, different from the first wavelength; light projecting means for projecting at least the first light to a position of inspection upon the substrate; first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a first direction from the inspection position as a result of irradiation with the first light; second detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a second direction, different from the first direction, from the inspection position as a result of irradiation with the first light; and inspecting means for inspecting a particle, if any, on the substrate on the basis of outputs of said first and second detecting means.
Claim 25
Dependent Claim 181 words
An inspection apparatus for inspecting a particle, if any, on a substrate having a pattern, said apparatus comprising: light producing means for producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization and a second wavelength, different from the first wavelength; light projecting means for projecting at least the first light to a position of inspection upon the substrate; first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a first direction from the inspection position as a result of irradiation with the first light; second detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a second direction, different from the first direction, from the inspection position as a result of irradiation with the first light; and inspecting means for inspecting a particle, if any, on the substrate on the basis of outputs of said first and second detecting means.
Claim 26
Dependent Claim 41 words
An apparatus according to claim 22, wherein the inspection position lies on a mask having a pattern to be transferred, and wherein a particle if any on the mask can be inspected while being distinguished from the pattern of the mask.
Claim 27
Dependent Claim 129 words
An inspection method for inspecting a particle, if any, on a substrate having a pattern, said method comprising the steps of: producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength; projecting at least the first light to a position of inspection upon the substrate; detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization; and inspecting a particle, if any, on the substrate on the basis of the detection in said detecting step.
Claim 28
Dependent Claim 129 words
An inspection method for inspecting a particle, if any, on a substrate having a pattern, said method comprising the steps of: producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength; projecting at least the first light to a position of inspection upon the substrate; detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization; and inspecting a particle, if any, on the substrate on the basis of the detection in said detecting step.
Claim 29
Dependent Claim 26 words
An inspection method according to claim 24, wherein said projecting step comprises deflecting at least the first light to optically scan a surface to be inspected.
Claim 30
Dependent Claim 36 words
A device manufacturing method, comprising the steps of: inspecting an original having a pattern in accordance with an inspection method as recited in claim 24; and transferring onto a substrate the pattern of the inspected original.
Claim 31
Dependent Claim 41 words
A device manufactured by a device manufacturing method which comprises the steps of: inspecting an original having a pattern in accordance with an inspection method as recited in claim 24; and transferring onto a substrate the pattern of the inspected original.
Claim 32
Dependent Claim 41 words
A method according to claim 24, wherein the inspection position lies on a mask having a pattern to be transferred, and wherein a particle if any on the mask can be inspected while being distinguished from the pattern of the mask.

References Cited (Backward Citations)

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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) 1999-01-22 1999-07-24 2000-01-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-01-22 2003-07-24 2004-01-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-01-22 2007-07-24 2008-01-23 $7700.00 Window Closed / Lapsed

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