Patent EP0462560A1 successfully refreshed from Google Patents.
EP0462560A1
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EP
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A reticle with phase-shifters and a method of fabricating the same
Assignee: Fujitsu Ltd
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Filing: 1991-06-18
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Granted: —
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Expires: 2011-06-18
Abstract
Abstract A reticle for projecting a fine pattern on an object surface comprises:- a transparent substrate; a first-type phase-shifter selectively patterned and deposited on the substrate producing a phase difference between light passing therethrough and light passing through other areas without phase-shifters; and a second-type phase-shifter selectively patterned and forming a groove in the substrate producing a phase difference between light passing therethrough and light passing through other areas without phase-shifters. The reticle may include a patterned shield layer which blocks transmission of light, and the phase difference of the first and second-type phase shifters is typically selected to be substantially equal to a half-wavelength of light used in photolithography. Another type of reticle comprises:- a transparent substrate; a phase-shifter formed by a first groove; and another phase-shifter formed by a second, deeper groove formed in the first groove.
Inventors
- 👤 Kenji c/o FUJITSU LIMITED Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:24
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/30; G03F1/68; G03F1/72; G03F1/74
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
72 words
A reticle for projecting a fine pattern on an object surface, said reticle comprising:- a transparent substrate, a first-type phase-shifter selectively patterned and deposited on said substrate producing a phase difference between light passing therethrough and light passing through other areas without phase-shifters, and a second-type phase-shifter selectively patterned and forming a groove in said substrate producing a phase difference between light passing therethrough and light passing through other areas without phase-shifters.
Claim 2
Dependent Claim
85 words
A reticle for projecting a fine pattern on an object surface, said reticle comprising:- a transparent substrate, a phase-shifter selectively patterned and forming a first groove in said substrate producing a phase difference between light passing through the first groove and light passing through other areas without phase-shifters, and another phase-shifter selectively patterned and formed within the region of said first groove, forming a second deeper groove producing another phase difference between light passing through the second groove and light passing through the first groove.
Claim 3
Dependent Claim
23 words
A reticle as claimed in claim 1 or 2, wherein said reticle further comprises a patterned shield layer which blocks transmission of light.
Claim 4
Dependent Claim
26 words
A reticle as claimed in any preceding claim, wherein the or each said phase difference is substantially equal to a half-wavelength of light used in photolithography.
Claim 5
Dependent Claim
28 words
A reticle as claimed in any preceding claim, wherein said first and second-type phase-shifters are formed side-by-side sharing a portion of peripheries of said pattern with each other.
Claim 6
Dependent Claim
44 words
A reticle as claimed in claims 1 and 3, wherein said shield layer is formed directly on said substrate, and a portion of said first-type phase-shifter and the whole of said second-type phase-shifter are formed in substrate areas not occupied by said shield layer.
Claim 7
Dependent Claim
36 words
A reticle as claimed in claim 2 and 3, wherein said shield layer is formed directly on said substrate and said first and second grooves are formed in substrate areas not occupied by said shield layer.
Claim 8
Dependent Claim
17 words
A reticle as claimed in claim 3, wherein said shield layer is formed on said first-type phase-shifter.
Claim 9
Dependent Claim
16 words
A reticle as claimed in any preceding claim, wherein said substrate is of quartz or glass.
Claim 10
Dependent Claim
23 words
A reticle as claimed in claim 3 or any of claims 4 to 9 as appended thereto, wherein said shield layer comprises chromium.
Claim 11
Independent Claim
66 words
A method of fabricating a reticle with groove-shaped phase-shifters, said method comprising the following steps:- disposing a reticle substrate in a focused ion beam apparatus, injecting a gas comprising a halogen on to a groove-forming region of the substrate, using a gas injection gun of said apparatus, and subjecting said substrate to ion beam irradiation by said apparatus to form a groove in said groove-forming region.
Claim 12
Independent Claim
136 words
A method of fabricating a phase-shifter on a reticle comprising a patterned shield layer selectively patterned and deposited on a substrate, said method comprising the following steps of:- removing a portion of said shield layer and any other layers formed thereon to form a region in which said phase-shifter is to be formed by utilising a focused ion beam apparatus, and exposing a reticle substrate surface in said region, injecting a gas comprising a halogen on to said exposed substrate surface through a gas injection gun of said apparatus, and subjecting said exposed substrate surface to ion beam irradiation by said apparatus, so as to form a groove in said substrate, the groove having a depth producing a desired phase difference between light passing through the groove and light passing through other parts of the substrate.
Claim 13
Dependent Claim
39 words
A method as claimed in claim 12, wherein prior to said method, the reticle is provided with a phase-shifter selectively patterned and deposited on said substrate, and wherein said removing step involves removing a portion of said deposited phase-shifter.
Claim 14
Independent Claim
112 words
A method of fabricating an additional phase-shifter on a reticle comprising a patterned shield layer and a phase-shifter formed by a selectively patterned groove in a substrate, said method comprising the following steps of:- disposing said reticle in a focused ion beam apparatus, injecting a gas comprising a halogen on to said groove, using a gas injection gun of said apparatus, and subjecting a bottom portion of the groove to ion beam irradiation by said apparatus, so as to form a deeper groove in the original groove, the deeper groove having a depth producing a desired phase difference between light passing through the deeper groove and light passing through the original groove.
Claim 15
Independent Claim
47 words
A method as claimed in any of claims 11 to 14, wherein said gas comprising a halogen is any selected from the group of:- carbon tetrafluoride gas (CF₄), nitrogen fluoride gas (NF₃), fluorine gas (F₂), sulphur fluoride gas (SF₆), hydrogen fluoride gas (HF), and chlorine gas (Cl₂).
Claim 16
Independent Claim
29 words
A method as claimed in any of claims 12 to 15, wherein the or each said phase difference is substantially equal to a half-wavelength of light used in photolithography.
References Cited (Backward Citations)
EP0383534A2
Cited
EP0395425A2
Cited
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