EP0140022A1
Expired / Lapsed
EP
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Optical self-alignment system
Assignee: Nagoya University
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Filing: 1984-08-30
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Granted: —
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Expires: 2004-08-30
Abstract
Abstract An optical self-alignment system comprises a laser source (12). a substrate (A) with a first diffraction grating for receiving laser beams (L) from the laser source (12), a substrate (B) with a second diffraction grating disposed within Fresnel zone of the first diffraction grating (A), and a photoelectric detector (C) for detecting Fraunhofer diffraction ray of Oth order by the second diffraction grating (B). In order to adjust the relative position between the two substrates (A,B) in orthogonal directions to the laser beams (L) at high accuracy, the first (A) and second (B) diffraction gratings are provided with two groups of combined diffraction gratings so that phase difference of 180° is produced in the Moire signals, maximum displacement point of Moire signal is detected with respect to relative position displacement of the diffraction gratings, and the substrates (A,B) are positioned at maximum intensity displacement of two groups of the Moire signals.
Inventors
- 👤 Shuzo Hattori
- 👤 Yoshiyuki 144 Nagoya University Uchida
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 16:10
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7049
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
446 words
Optical self-alignment system which adjusts relative position between a pair of substrates (1,2) spaced at a prescribed distance, said self-alignment system comprising: a first grating plate (A;A') installed on one (1) of said two substrates (1,2); a second grating plate (B;B') installed on the other (2) of said two substarates (1,2) and in parallel to said first grating plate (A;A'); a laser source (12) for irradiating laser beams (L) to said first grating plate (A;A'); a position arranging means for arranging the position of either of said two substrates (1,2) according to Moire signals carried on the laser beams (L) passing through said first and second grating plates (A,B;A',B'); a driving system (F X ,F y ) for shifting said either of the two substrates (1,2) in a required direction by the received control signals from said position arranging means; characterized in that said position arranging means includes first and second diffraction grating segments (A 1 -A 8 ;A' 1 -A' 4 ) formed on said first grating plate (A,A'), third and fourth diffraction grating segments (B 1 -B 4 ;B' 1 -B' 4 ) formed on said second grating plate (B;B'), a first photoelectric detector (C 1 ,C 3 ) for separating and detecting Moire signals from the laser beams (L) coming by way of said first and third diffraction grating segments (A 1 ,A 3 ,A 5 , A 7 ,B 1 ,B 3 ;A' 1 ,A' 3 ,B' 1 'B' 3 ), a second photoelectric detector (C 2 ,C 4 ) for separating and detecting Moire signals from the laser beams (L) coming by way of said second and fourth diffraction grating segments (A 2 ,A 4 ,A 6 ,A 8 ,B 2 , B 4 ;A' 4 ,A' 4 ,B' 2 ,B' 4 ), a comparator (D ,D ) for comparing the detected signals from said first and second photoelectric detectors (C 1 -C 4 ), and a controller (E ,E ) for delivering said control signals according to the comparison signals from said comparator (D X ,D y ), and that when said first and second grating plates (A,B;A',B') are matched, said third diffraction grating segment (B 1 ,B 3 ;B' 1 ,B' 3 ) is formed in the position with the delayed phase in respect to said first diffraction grating segment (A 1 ,A 3 ,A 5 ,A 7 ;A' 1 ,A' 3 ) and also said fourth diffraction grating segment (B 2 ,B 4 ;B' 2 ,B' 4 ) is formed in the position with the advanced phase in respect to said second diffraction grating segment (A 2 ,A 4 ,A 6 ,A 8 :A' 2 ,A' 4 ).
Claim 2
Dependent Claim
446 words
Optical self-alignment system which adjusts relative position between a pair of substrates (1,2) spaced at a prescribed distance, said self-alignment system comprising: a first grating plate (A;A') installed on one (1) of said two substrates (1,2); a second grating plate (B;B') installed on the other (2) of said two substarates (1,2) and in parallel to said first grating plate (A;A'); a laser source (12) for irradiating laser beams (L) to said first grating plate (A;A'); a position arranging means for arranging the position of either of said two substrates (1,2) according to Moire signals carried on the laser beams (L) passing through said first and second grating plates (A,B;A',B'); a driving system (F X ,F y ) for shifting said either of the two substrates (1,2) in a required direction by the received control signals from said position arranging means; characterized in that said position arranging means includes first and second diffraction grating segments (A 1 -A 8 ;A' 1 -A' 4 ) formed on said first grating plate (A,A'), third and fourth diffraction grating segments (B 1 -B 4 ;B' 1 -B' 4 ) formed on said second grating plate (B;B'), a first photoelectric detector (C 1 ,C 3 ) for separating and detecting Moire signals from the laser beams (L) coming by way of said first and third diffraction grating segments (A 1 ,A 3 ,A 5 , A 7 ,B 1 ,B 3 ;A' 1 ,A' 3 ,B' 1 'B' 3 ), a second photoelectric detector (C 2 ,C 4 ) for separating and detecting Moire signals from the laser beams (L) coming by way of said second and fourth diffraction grating segments (A 2 ,A 4 ,A 6 ,A 8 ,B 2 , B 4 ;A' 4 ,A' 4 ,B' 2 ,B' 4 ), a comparator (D ,D ) for comparing the detected signals from said first and second photoelectric detectors (C 1 -C 4 ), and a controller (E ,E ) for delivering said control signals according to the comparison signals from said comparator (D X ,D y ), and that when said first and second grating plates (A,B;A',B') are matched, said third diffraction grating segment (B 1 ,B 3 ;B' 1 ,B' 3 ) is formed in the position with the delayed phase in respect to said first diffraction grating segment (A 1 ,A 3 ,A 5 ,A 7 ;A' 1 ,A' 3 ) and also said fourth diffraction grating segment (B 2 ,B 4 ;B' 2 ,B' 4 ) is formed in the position with the advanced phase in respect to said second diffraction grating segment (A 2 ,A 4 ,A 6 ,A 8 :A' 2 ,A' 4 ).
Claim 3
Dependent Claim
34 words
Optical self-alignment system as set forth in claim 1, wherein mutual distance between said first and second diffraction grating segment (A 1 -A 8 ;A' 1 -A' 4 ) is set within Fresnel zone.
Claim 4
Dependent Claim
48 words
Optical self-alignment system as set forth in claim 1, wherein said first and second photoelectric detectors (C 1 -C 4 ) are arranged within Fraunhofer's zone of Oth order by said second diffraction grating segment (A 2 ,A 4 ,A 6 ,A 8 ;A' 2 ,A' 4 ).
Claim 5
Dependent Claim
57 words
4 . Optical self-alignment system as set forth in claim 1, wherein either said first and second diffraction grating segments (A 1 -A 8 ;A' 1 -A' 4 ) or said third and fourth diffraction grating segments (B 1 -B 4 ; B' 1 -B' 4 ) or both are formed as penetrating type diffraction grating segments.
Claim 6
Dependent Claim
55 words
Optical self-alignment system as set forth in claim 1, wherein either said first and second diffraction grating segments (A 1 -A 8 ;A' 1 -A' 4 ) or said third and fourth diffraction grating segments (B 1 -B 4 ; B' 1 -B' 4 ) or both are formed as reflecting type diffraction grating segments.
Claim 7
Dependent Claim
44 words
Optical self-alignment system as set forth in claim 1, wherein said controller(E x ,E y ) delivers said control signal to said driving system (F x ,F y ) so that said comparison signal from said comparator (D x ,D y ) becomes zero.
Claim 8
Dependent Claim
30 words
Optical self-alignment system as set forth in claim 1, wherein said advanced phase and said delayed phase are set so that sum of the absolute value thereof becomes 180 .
Claim 9
Dependent Claim
24 words
Optical self-alignment system as set forth in claim 7, wherein said advanced phase and said delayed phase are set to 90° in absolute value.
Claim 10
Dependent Claim
44 words
Optical self-alignment system as set forth in claim 1, wherein the line-and-space of said diffraction grating segments (A 1 -A 8 ,B 1 -B 4 ;A' 1 -A' 4 ,B' 1 -B' 4 ) is grooved in the width of two sorts or more.
Claim 11
Dependent Claim
30 words
Optical self-alignment systems set forth in claim 1, wherein said driving system (F ,F ) is provided with driving portions of two sorts or more being different in travelling amount.
Claim 12
Dependent Claim
59 words
Optical self-alignment system as set forth in claim 1, wherein two pairs of said position arranging means and said driving systems (F x ,F y ) are installed, and one of said driving system (F x ;F y ) drives said substrate in the driving direction intersecting with the driving direction of the other (F x ;F y ).
Claim 13
Dependent Claim
55 words
Optical self-alignment system as set forth in claim 11, wherein driving direction of one driving system (F x ;F y ) and driving direction of other driving system (F x ;F y ) are orthogonal with each other, and cross lines (9,10) are grooved at the center of said first and second grating plates (A,B;A',B').
Claim 14
Dependent Claim
42 words
Optical self-alignment system as set forth in claim 1, wherein multiple pairs of said position arranging means and said driving systems (F ,F ) are installed, wherein the driving direction of said driving system (F ,F ) is intersecting with each other.
References Cited (Backward Citations)
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