US4568835A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting foreign matters on a planar substrate
Assignee: Nikon Corp
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Filing: 1982-11-02
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Granted: 1986-02-04
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Expires: 2002-11-02
Abstract
Abstract An apparatus for detecting foreign matter present on a planar substrate comprises apparatus for scanning the surface of the substrate with an oblique incident light beam, apparatus for photo-electrically detecting the scattered light generator in the trajectory of the light beam scanning on the substrate, and apparatus for eliminating stray light unnecessary for the foreign matter detection.
Inventors
- 👤 Kazunori Imamura
- 👤 Akikazu Tanimoto
- 👤 Nobutoshi Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:18
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/94; G01N21/95; G01N21/956; G01N2201/00; G01N2201/06; G01N2201/064; G01N2201/0642; G01N2201/10; G01N2201/104
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
186 words
An apparatus for detecting foreign matter present on a planar substrate comprising: (a) irradiating means for generating a light beam obliquely entering one surface of said substrate and including scanning means for causing said light beam to scan said surface; (b) discriminating means which includes photoelectric converting means so positioned as to receive a part of the light scattered from said foreign matter and adapted to generate electride output signals corresponding to the intensity of the received light, and to identify the presence of said foreign matter in response to said electric output signals; and (c) absorbing means positioned on the optical path of the light beam regularly reflected by said surface and adapted to absorb said regularly reflected light beam, said absorbing means including a regular reflector member having a light absorbing property with respect to said light beam and which is positioned across the optical path of said regularly reflected light beam, and an optical trap member which is positioned opposite to said regular reflector member and which is used to absorb said regularly reflected light beam regularly reflected by said regular reflector member.
Claim 2
Independent Claim
186 words
An apparatus for detecting foreign matter present on a planar substrate comprising: (a) irradiating means for generating a light beam obliquely entering one surface of said substrate and including scanning means for causing said light beam to scan said surface; (b) discriminating means which includes photoelectric converting means so positioned as to receive a part of the light scattered from said foreign matter and adapted to generate electride output signals corresponding to the intensity of the received light, and to identify the presence of said foreign matter in response to said electric output signals; and (c) absorbing means positioned on the optical path of the light beam regularly reflected by said surface and adapted to absorb said regularly reflected light beam, said absorbing means including a regular reflector member having a light absorbing property with respect to said light beam and which is positioned across the optical path of said regularly reflected light beam, and an optical trap member which is positioned opposite to said regular reflector member and which is used to absorb said regularly reflected light beam regularly reflected by said regular reflector member.
Claim 3
Dependent Claim
53 words
A foreign matter detecting apparatus according to claim 1, wherein each of said regular reflector member and said optical trap member is positioned along the scanning direction of said light beam and has a dimension sufficiently covering the range of the optical path of said regularly reflected light beam displaced by said scanning.
Claim 4
Dependent Claim
71 words
A foreign matter detecting apparatus according to claim 1, wherein said photoelectric converting means is positioned in a space of the incident side with respect to the entering position of said scanning light beam, and further includes light sheild means positioned between said space of the incident side containing the optical path of said entering light beam as well as said photoelectric converting means, and a space at the opposite side.
Claim 5
Dependent Claim
35 words
A foreign matter detecting apparatus according to claim 1, further comprising a light shield member of plate-form having an edge extending parallel to said surface of said substrate adjacent to the surface of the substrate.
Claim 6
Dependent Claim
35 words
A foreign matter detecting apparatus according to claim 4, wherein said light shield member is positioned obliquely to said surface of said substrate and substantially parallel to the optical path of said entering light beam.
Claim 7
Independent Claim
194 words
An apparatus for detecting foreign matter present on a planar substrate having a light-transmitting property, comprising: (a) irradiating means for generating a light beam obliquely entering one surface of said substrate and including scanning means for causing said light beam to scan said surface; (b) discriminating means which includes photoelectric converting means so positioned as to receive a part of the light scattered from said foreign matter and adapted to generate electric output signals corresponding to the intensity of the received light, and to identify the presence of said foreign matter in response to said electric output signals; and (c) absorbing means positioned on the optical path of the light beam transmitted by said substrate and emerging from the outer surface thereof and adapted to absorb said transmitted light beam, said absorbing means including a regular reflector member having a light absorbing property property with respect to said light beam and which is positioned across the optical path of said transmitted light beam, and an optical trap member which is positioned opposite to said regular reflector member and which is used to absorb said transmitted light beam regularly reflected by said regular reflector member.
Claim 8
Independent Claim
194 words
An apparatus for detecting foreign matter present on a planar substrate having a light-transmitting property, comprising: (a) irradiating means for generating a light beam obliquely entering one surface of said substrate and including scanning means for causing said light beam to scan said surface; (b) discriminating means which includes photoelectric converting means so positioned as to receive a part of the light scattered from said foreign matter and adapted to generate electric output signals corresponding to the intensity of the received light, and to identify the presence of said foreign matter in response to said electric output signals; and (c) absorbing means positioned on the optical path of the light beam transmitted by said substrate and emerging from the outer surface thereof and adapted to absorb said transmitted light beam, said absorbing means including a regular reflector member having a light absorbing property property with respect to said light beam and which is positioned across the optical path of said transmitted light beam, and an optical trap member which is positioned opposite to said regular reflector member and which is used to absorb said transmitted light beam regularly reflected by said regular reflector member.
Claim 9
Dependent Claim
71 words
A foreign matter detecting apparatus according to claim 6, wherein said photoelectric converting means is positioned in a space of the incident side with respect to the entering position of said scanning light beam, and further includes light shield means positioned between said space of the incident side containing the optical path of said entering light beam as well as said photoelectric converting means, and a space at the opposite side.
Claim 10
Dependent Claim
52 words
A foreign matter detecting apparatus according to claim 6, wherein each of said regular reflector member and said optical trap member is positioned along the scanning direction of said light beam and has a dimension sufficiently covering the range of the optical path of said transmitted light beam displaced by said scanning.
Claim 11
Dependent Claim
37 words
A foregoing matter detecting apparatus according to claim 6, further comprising a light sheild member of plate-form having an edge extending parallel to the other surface of said substrate adjacent to the other surface of the substrate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |