EP0179438A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A projection aligner of a lithographic system
Assignee: Hitachi Ltd
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Filing: 1985-10-22
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Granted: —
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Expires: 2005-10-22
Abstract
Abstract The present invention relates, in a projection aligner wherein a mask and a wafer are held proximate and wherein a circuit pattern depicted on the mask is transferred onto the wafer, to a method of detecting the respective positions of the mask and the wafer for the relative positioning between the mask and the wafer. To the end of dispensing with the withdrawal of a microscope objective in such a way that the objective of a microscope for detecting the mask and the wafer and projection light, for example, an X-ray are prevented from interfering, thereby to achieve the enhancement of throughput and to permit the detection of the positions of the mask and the wafer even during projection, the present invention consists in that the objective of the microscope is inclined with respect to a perpendicular to the plane of the mask or the plane of the wafer being a plane to-be-detected, so as not to interfere with the projection light, for example, the X-ray, whereby the circuit pattern can be transferred while the relative positions of the mask and the wafer are being detected.
Inventors
- 👤 Yoshihiro Komeyama
- 👤 Yukio Kembo
- 👤 Asahiro Kuni
- 👤 Ryuuichi Higashi-No-Machi Funatsu
- 👤 Akira Sun Palace Shimonagaya 503 Inagaki
- 👤 Minoru Ikeda
- 👤 Keiichi Okamoto
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 09:10
CPC Classifications
G; G03; G03F; G03F9/00; G03F9/70; G03F9/7003; G03F9/7023; G03F9/7049; G03F9/7073; G03F9/7076
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
37 words
In a method wherein-a substantially flat object to-be-handled is detected by an objective; a method of detecting a position characterized in that an optic axis of said objective is inclined with.respect to a perpendicular to the object.
Claim 2
Dependent Claim
37 words
In a method wherein-a substantially flat object to-be-handled is detected by an objective; a method of detecting a position characterized in that an optic axis of said objective is inclined with.respect to a perpendicular to the object.
Claim 3
Dependent Claim
23 words
A method of detecting a position as defined in Claim 1, wherein said optic axis is inclined by 10 ° - 60 °.
Claim 4
Dependent Claim
58 words
A method of detecting a position as defined in Claim 1, wherein a diffraction grating is arranged in substantial agreement with a focusing plane on which the object detected by the inclined objective is focused, and light reflected from said diffraction grating substantially orthogonally is focused by a second objective, thereby to detect the position of the object.
Claim 5
Dependent Claim
33 words
A method of detecting a position as defined in Claim 1, wherein the object (A) whose base is substantially transparent and the object (B) which is proximate thereto are detected simultaneously or individually.
Claim 6
Dependent Claim
157 words
In a position detecting method wherein alignment positions of a plurality of objects placed in proximity to or in contact with each other are detected on the same side as that of projection light; a position detecting method characterized by comprising an alignment pattern magnifying optical system which does not interfere with the projection light and a detecting optic axis of which is inclined by a predetermined angle with respect to a plane orthogonal to alignment planes of the plurality of objects, and an illuminating optical system which does not interefere with the projection light and an illuminating optic axis of which is inclined by a predetermined angle with respect to a plane orthogonal to the alignment planes of the plurality of objects, alignment patterns used being patterns which are symmetric on a plane orthogonal to the alignment planes of the plurality of objects, so as to detect one alignment direction with the single detecting optic axis.
Claim 7
Dependent Claim
157 words
In a position detecting method wherein alignment positions of a plurality of objects placed in proximity to or in contact with each other are detected on the same side as that of projection light; a position detecting method characterized by comprising an alignment pattern magnifying optical system which does not interfere with the projection light and a detecting optic axis of which is inclined by a predetermined angle with respect to a plane orthogonal to alignment planes of the plurality of objects, and an illuminating optical system which does not interefere with the projection light and an illuminating optic axis of which is inclined by a predetermined angle with respect to a plane orthogonal to the alignment planes of the plurality of objects, alignment patterns used being patterns which are symmetric on a plane orthogonal to the alignment planes of the plurality of objects, so as to detect one alignment direction with the single detecting optic axis.
Claim 8
Dependent Claim
27 words
A position detecting method according to Claim 5, wherein the detecting optic axis of said alignment pattern magnifyign optical system is held stationary during alignment and projection.
Claim 9
Dependent Claim
18 words
A position detecting method according to Claim 5, wherein the alignment patterns are provided in a projection region.
Claim 10
Dependent Claim
35 words
A position detecting method according to Claim 5, wherein the magnifying optical systems and the illuminating optical systems which form respective sets are moved with each set of the systems substantially synchronized with each other.
Claim 11
Dependent Claim
26 words
A position detecting method according to Claim 5, wherein an objective which is used in said magnifying optical system has an NA of at most 0.4.
Claim 12
Dependent Claim
28 words
A position detecting method according to Claim 5, wherein the inclination angle of the detecting optic axis with respect to the orthogonal plane is at most 70 °.
Claim 13
Dependent Claim
95 words
In a projection aligner wherein a mask and a wafer are confronted with a gap of 5 - 40 pm therebetween, and projection light is thrown from above a mask surface so as to transfer a circuit pattern-on the mask surface onto the wafer; a position detecting method characterized in that positioning marks provided on the wafer and the mask are illuminated from within a projection region toward the exterior of the projection region, whereupon resulting reflected light is detected outside the projection region, thereby to find relative positions of the wafer and the mask.
Claim 14
Dependent Claim
95 words
In a projection aligner wherein a mask and a wafer are confronted with a gap of 5 - 40 pm therebetween, and projection light is thrown from above a mask surface so as to transfer a circuit pattern-on the mask surface onto the wafer; a position detecting method characterized in that positioning marks provided on the wafer and the mask are illuminated from within a projection region toward the exterior of the projection region, whereupon resulting reflected light is detected outside the projection region, thereby to find relative positions of the wafer and the mask.
Claim 15
Dependent Claim
46 words
A position detecting method according to Claim 11, wherein Fresnel zone marks are provided as the positioning marks on the mask and the wafer, and focuses thereof by diffracted light are formed within an identical plane perpendicular to an optic axis of a detecting optical system.
Claim 16
Dependent Claim
56 words
A position detecting method according to Claim 11 or 12, wherein an objective of a detecting optical system is inclined with respect to a perpendicular to mask and wafer planes, and focuses by diffracted light from the mask and the wafer are formed within an identical plane perpendicular to an optic axis of the inclined objective.
Claim 17
Dependent Claim
45 words
A position detecting method according to Claim 11, 12 or 13, wherein unidimensional Fresnel zones arranged on wafer and mask surfaces are put into the shape of a wedge, whereby they are focused on a plane perpendicular to an optic axis of a detecting objective.
Claim 18
Dependent Claim
21 words
A position detecting method according to Claim 14, wherein dimensions of the wedge shape of the Fresnel zones are changed stepwise.
References Cited (Backward Citations)
No citation records indexed.
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