EP0492630A2
Expired / Lapsed
EP
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Phase shifting mask
Assignee: NEC Corp
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Filing: 1991-12-24
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Granted: —
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Expires: 2011-12-24
Abstract
Abstract A phase shifting mask includes an opaque layer (26) having three adjacent apertures (28a,b,c) which comprise a predetermined pattern, and at least two phase shifters (50,52) each having a different shift amount. At least two of the apertures (28b,c) are covered with the phase shifters (50,52) so that a phase difference between each two adjacent apertures is approximately 120 DEG (1/3 lambda ). Therefore, light intensity at a medial area between each two adjacent apertures is decreased in comparison with independent lights passing through the apertures. <IMAGE>
Inventors
- 👤 Hiroyoshi Tanabe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:43
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30; G03F1/28
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
115 words
A phase shifting mask comprising: a photo-mask member having three adjacent apertures which are a part of a predetermined mask pattern; and at least two phase shifters for covering at least two of said three adjacent apertures to provide said three adjacent apertures with three phase shift amounts φ 1, φ 2 and φ 3; wherein said three phase shift amounts φ 1, φ 2 and φ 3 meet below equations; | φ 1 - φ 2 + n× 360° | ≒ 120° | φ 2 - φ 3 + m× 360° | ≒ 120° | φ 3 - φ 1 + k× 360° | ≒ 120° when n, m and k are arbitrary integers.
Claim 2
Dependent Claim
84 words
A phase shifting mask comprising: a transparent substrate; a shading layer formed on said transparent substrate to have a plurality of apertures comprising three adjacent apertures which comprise a predetermined pattern; and at least two phase shifters each having a different shift amount to shift a phase of coherent illumination transmitting therethrough; wherein at least two of said three adjacent apertures are covered with said at least phase shifters so that phase difference between each two adjacent apertures is 100 ° to 140° .
Claim 3
Dependent Claim
22 words
A phase shifting mask, according to claim 2, wherein: said phase difference between each two adjacent apertures is 120° (1/3 λ ).
Claim 4
Dependent Claim
46 words
A phase shifting mask, according to claim 2, wherein: said at least two phase shifters have shift amounts of 120° (1 /3 λ ) and 240 ° (2/3 λ ), respectively; and a remaining one of said adjacent apertures is not provided with a phase shifter.
Claim 5
Dependent Claim
38 words
A phase shifting mask, according to claim 2, wherein: said at least two phase shifters comprise three phase shifters having shift amounts of 60° (1/6 λ ), 180° (1/2 λ ) and 300 ° (5/6 λ ), respectively.
Claim 6
Dependent Claim
30 words
A phase shifting mask, according to claims 2 to 5 wherein: said phase shifter has a fine structure and holds said shading layer in addition to means for phase shifting.
References Cited (Backward Citations)
No citation records indexed.
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