EP0237102A1
Expired / Lapsed
EP
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Arrangement for aligning a mask and a substrate relative to each other
Assignee: Koninklijke Philips NV
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Filing: 1987-02-25
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Granted: —
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Expires: 2007-02-25
Abstract
Abstract An arrangement is described for aligning a mask (1) and a substrate (3) relative to each other by means of grating marks (M 1 , M 2 ; P 1 , P 2 ) in the mask and in the substrate. A diaphragm (32) is arranged in the path of the alignment beam (b') behind the mask grating (M 2 ) and transmits only specific diffraction orders of the gratings (P 2 , M 2 ), so that the alignment signal (S A ) contains less undesired components and becomes more accurate.
Inventors
- 👤 Jan Evert Van Der Werf
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 16:01
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7049
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
197 words
An arrangement for aligning relative to each other a mask and a substrate which are both provided with alignment marks in the form of diffraction gratings, which arrangement comprises a radiation source producing an alignment beam, a first lens system for imaging a substrate grating and a mask grating onto each other, a radiation-sensitive detection system in the path of the alignment beam which has interacted with both the substrate grating and the mask grating, and a diaphragm arranged in the path of the alignment beam issuing from the substrate grating to select radiation which has been diffracted in specific diffraction orders for the purpose of the alignment, characterized in that a second lens system for imaging the pupil of the first lens system is arranged in the radiation path of the alignment beam between the mask and the detection system, in that the diaphragm is arranged in the plane of the pupil image, and in that said diaphragm comprises apertures at the locations of incidence of beam portions comprising those components of the first-order subbeams issuing from the substrate grating which are diffracted in the zeroth order and the first diffraction orders by the mask grating.
Claim 2
Dependent Claim
197 words
An arrangement for aligning relative to each other a mask and a substrate which are both provided with alignment marks in the form of diffraction gratings, which arrangement comprises a radiation source producing an alignment beam, a first lens system for imaging a substrate grating and a mask grating onto each other, a radiation-sensitive detection system in the path of the alignment beam which has interacted with both the substrate grating and the mask grating, and a diaphragm arranged in the path of the alignment beam issuing from the substrate grating to select radiation which has been diffracted in specific diffraction orders for the purpose of the alignment, characterized in that a second lens system for imaging the pupil of the first lens system is arranged in the radiation path of the alignment beam between the mask and the detection system, in that the diaphragm is arranged in the plane of the pupil image, and in that said diaphragm comprises apertures at the locations of incidence of beam portions comprising those components of the first-order subbeams issuing from the substrate grating which are diffracted in the zeroth order and the first diffraction orders by the mask grating.
References Cited (Backward Citations)
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