EP0091199A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Projection alignment apparatus
Assignee: Control Data Corp
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Filing: 1983-03-04
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Granted: —
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Expires: 2003-03-04
Abstract
Abstract A projection alignment apparatus comprises a circuit mask holder (12) for securing a circuit mask (10) having a circuit pattern therein; a chuck for securing a wafer (20) in a wafer plane (22); an optical system (15) including mirrors (16); and a light source (5) for projecting light through the circuit mask to produce an image of said circuit pattern through the optical system on the wafer. A first target mask (25) has at least two first alignment patterns (26a-26i) thereon, at least one (26d, 26e) which is vertically displaced from a centre of the first target mask and at least one (26b, 26c) of which is horizontally displaced from said centre, each of the first alignment patterns having a horizontally disposed pattern (35, 45) and a vertically disposed pattern (30,40). The first target mask is secured in said mask holder. A second target mask has at least two second alignment patterns (51a-51i) thereon, at least one (51d, 51e) which is vertically displaced from a centre of the second target mask and at least one (51b, 51c) of which is displaced from said centre, each of the second mask patterns having a horizontally disposed pattern (60, 70) and a vertically disposed pattern (55, 65). The second target mask is secured in said wafer plane. The light source is arranged to project light through the first circuit mask to carry the image of the first alignment patterns through the optical system and be superimposed upon the second circuit mask. The first alignment patterns and the second alignment patterns have an aligned position where the first alignment patterns are superimposed over and aligned with the second alignment patterns. A mechanism is provided for producing relative movement between the first target mask and the second target mask to attempt to put the first alignment patterns and the second alignment patterns in the aligned position and for adjusting the mirrors of the optical system. ,
Inventors
- 👤 Donald Wayne Betz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 06:35
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70483; G03F7/70591; G03F7/70216; G03F7/70233; G03F7/70605; G03F7/70616; G03F7/70633
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
408 words
A projection alignment apparatus comprising a circuit mask holder (12) suitable for securing a circuit mask (10), said circuit mask having a circuit pattern thereon: means for securing a wafer (20) in a wafer plane (22), an optical system (15) which includes a plurality of mirrors (16); and a light source (5) for projecting light through said circuit mask to produce an image of said circuit pattern through said optical system on said wafer; characterised by comprising: a first target mask (25) having at least two first alignment patterns (26a-26i) thereon, at least one (26d, 26e) of said first alignment patterns being vertically displaced from a centre of the first target mask, at least one (26b, 26c) of said first alignment patterns being horizontally displaced from said centre, each of said first alignment patterns having a horizontally disposed pattern (35, 45) and a vertically disposed pattern (30, 40), said first target mask being secured in said mask holder; a second target mask having at least two second alignment patterns (51a-51i)thereon, at least one (51d, 51e) of said second alignment patterns being vertically displaced from a centre of the second target mask, at least one (51b, 51c) of said second alignment patterns being horizontally displaced from said centre, each of said second mask patterns having a horizontally disposed pattern (60, 70) and a vertically disposed pattern (55, 65); said second target mask being secured in said wafer plane, said light source being arranged to project light through said first circuit mask to carry the image of said first alignment patterns through said optical system and be superimposed upon said second circuit mask, said first alignment patterns and said second alignment patterns having an aligned position wherein said first alignment patterns are superimposed over and aligned with said second alignment patterns, said horizontal and vertical patterns of said vertically displaced first alignment pattern being aligned respectively with said horizontal and vertical patterns of said vertically displaced second alignment pattern in said aligned position, said horizontal and vertical patterns of said horizontally displaced first alignment pattern being aligned respectively with said horizontal and vertical patterns of said horizontally displaced second alignment pattern in said aligned position; means for producing relative movement between.said first target mask and said second target mask to attempt to put said first alignment patterns and said second alignment patterns in said aligned p p sition; and means for adjusting said plurality of mirrors of said optical system.
Claim 2
Dependent Claim
408 words
A projection alignment apparatus comprising a circuit mask holder (12) suitable for securing a circuit mask (10), said circuit mask having a circuit pattern thereon: means for securing a wafer (20) in a wafer plane (22), an optical system (15) which includes a plurality of mirrors (16); and a light source (5) for projecting light through said circuit mask to produce an image of said circuit pattern through said optical system on said wafer; characterised by comprising: a first target mask (25) having at least two first alignment patterns (26a-26i) thereon, at least one (26d, 26e) of said first alignment patterns being vertically displaced from a centre of the first target mask, at least one (26b, 26c) of said first alignment patterns being horizontally displaced from said centre, each of said first alignment patterns having a horizontally disposed pattern (35, 45) and a vertically disposed pattern (30, 40), said first target mask being secured in said mask holder; a second target mask having at least two second alignment patterns (51a-51i)thereon, at least one (51d, 51e) of said second alignment patterns being vertically displaced from a centre of the second target mask, at least one (51b, 51c) of said second alignment patterns being horizontally displaced from said centre, each of said second mask patterns having a horizontally disposed pattern (60, 70) and a vertically disposed pattern (55, 65); said second target mask being secured in said wafer plane, said light source being arranged to project light through said first circuit mask to carry the image of said first alignment patterns through said optical system and be superimposed upon said second circuit mask, said first alignment patterns and said second alignment patterns having an aligned position wherein said first alignment patterns are superimposed over and aligned with said second alignment patterns, said horizontal and vertical patterns of said vertically displaced first alignment pattern being aligned respectively with said horizontal and vertical patterns of said vertically displaced second alignment pattern in said aligned position, said horizontal and vertical patterns of said horizontally displaced first alignment pattern being aligned respectively with said horizontal and vertical patterns of said horizontally displaced second alignment pattern in said aligned position; means for producing relative movement between.said first target mask and said second target mask to attempt to put said first alignment patterns and said second alignment patterns in said aligned p p sition; and means for adjusting said plurality of mirrors of said optical system.
Claim 3
Dependent Claim
35 words
An apparatus as claimed in claim 1 characterised in that each of said horizontal patterns and said vertical patterns of said first alignment patterns consists of a first comb pattern of a row of teeth.
Claim 4
Dependent Claim
35 words
An apparatus as claimed in claim 2 characterised in that each of said horizontal patterns and said vertical patterns of said second alignment patterns consists of a second comb pattern of a row of teeth.
Claim 5
Dependent Claim
67 words
An apparatus as claimed in claim 3 characterised in that, in said aligned position, each of said horizontal first comb patterns of said first alignment patterns is aligned with a corresponding horizontal second comb pattern of said second alignment patterns, and each of said vertical first comb patterns of said first alignment patterns is aligned with a corresponding vertical second comb pattern of said second alignment patterns.
Claim 6
Independent Claim
24 words
An apparatus as claimed in any of claims 2 to 4 characterised in that each of said first comb patterns includes a central tooth.
Claim 7
Independent Claim
24 words
An apparatus as claimed in any of claims 3 to 5 characterised in that each of said second comb pattern includes a central tooth.
Claim 8
Dependent Claim
49 words
An aapparatus as claimed in claim 6 when dependent upon claim 5 characterised in that, in said aligned position, said central teeth of each of said horizontal and vertical first comb patterns are aligned, respectively, with said central teeth of each of said horizontal and vertical second comb patterns.
Claim 9
Dependent Claim
40 words
B. An apparatus as claimed in any of claims 3 to 7 characterised in that said teeth of each of said first comb patterns are evenly spaced, and said teeth of each of said second comb patterns are evenly spaced.
Claim 10
Dependent Claim
35 words
An apparatus as claimed in claim 8 characterised in that said teeth of each of the first comb patterns are spaced a greater distance apart than said teeth of each of said second comb patterns.
Claim 11
Independent Claim
131 words
An apparatus as claimed in any preceding claim characterised in that said first target mask has at least four first alignment patterns thereon, at least two of which are vertically displaced from, and disposed on opposite sides of the centre of the first target mask, and at least two of said first alignment patterns being horizontally displaced from, and disposed on opposite sides of the centre of the first target mask, said second target mask having at least four second alignment patterns thereon, at least two of which are vertically displaced from, and spaced on opposite sides of the centre of the second target mask, and at least two of said second alignment patterns being horizontally displaced from, and spaced on opposite sides of, the centre of the second target mask.
Claim 12
Dependent Claim
45 words
ll. An apparatus as claimed in claim 10 characterised in that said at least four first alignment patterns of said first target mask are superimposed upon and aligned with said at least four second alignment patterns of said second target mask in said aligned position.
Claim 13
Dependent Claim
255 words
An apparatus as claimed in claim 11 characterised in that at least two of said first alignment patterns are disposed along a line running vertically through said centre of the first target mask, and at least two of said first alignment patterns are disposed along a line running horizontally through said centre of the first target mask, said first target mask including at least one first alignment pattern disposed on each side of said centre of the first target mask along diagonal lines running through said centre of the first target mask from an upper left hand corner to a lower right hand corner and from a lower left hand corner of said mask to an upper right hand corner, at least two of said second alignment patterns are disposed along a line running vertically through said centre of the second target mask, and at least two of said second alignment patterns are disposed along a line running horizontally through the centre of the second target mask, said second target mask includes at least one second alignment pattern disposed on each side of said centre of the second target mask along diagonal lines running through said centre of the second target mask from an upper left hand corner to a lower right hand corner and from a lower left hand corner to an upper right corner of said mask; the arrangement being such that in said aligned position, each of said first alignment patterns is superimposed upon and aligned with a corresponding second alignment pattern.
Claim 14
Independent Claim
81 words
An apparatus as claimed in any of claims 1 to 9 characterised in that each of said first alignment patterns has a pattern centre and one of said horizontally disposed patterns is disposed above said pattern centre and one of said horizontally disposed patterns is disposed below said pattern centre, one of said vertically disposed patterns being disposed to the left of said pattern centre and one of said vertically disposed patterns being disposed to the right of said pattern centre.
Claim 15
Dependent Claim
73 words
Apparatus as claimed in claim 13 characterised in that each of said second alignment patterns has a pattern centre and one of said horizontally disposed patterns disposed above said pattern centre and one of said horizontally disposed patterns disposed below said pattern centre, one of said vertical patterns being disposed to the right of said pattern centre, and one of said vertically disposed patterns being disposed to the left of said pattern centre.
Claim 16
Dependent Claim
94 words
Apparatus as claimed in claim 14 characterised in that said horizontally and vertically disposed patterns of each of said first alignment patterns are arranged in a first box type configuration, and said horizontally and vertically disposed patterns of each of said second alignment pattern are disposed in a second box type configuration, the arrangement being such that in said aligned position said horizontally and vertically disposed patterns of each of said second alignment patterns fit within the first box type configuration and abut said horizontal- and vertical patterns of the corresponding second alignment pattern.
Claim 17
Independent Claim
51 words
An apparatus as claimed in any preceding claim characterised in that each of said second alignment patterns has a cross-hair disposed at its centre each said first alignment pattern having a cross hair bracket disposed at its centre, said cross-hair being centred in said cross hair bracket in said aligned position.
References Cited (Backward Citations)
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