EP0477035A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Phase shift layer-containing photomask, and its production and correction
Assignee: Dai Nippon Printing Co Ltd
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Filing: 1991-09-23
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Granted: —
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Expires: 2011-09-23
Abstract
Abstract A photomask blank for preparing a reticle for use in the production of integrated circuits comprises a substrate 30, an electrically conductive layer 31, a light-shielding thin film 32 and an ionizing radiation resist 33 formed of a coated spin-on-glass layer. A pattern is directly formed on the layer 33 by electron beam exposure. After development with a solvent to give a resist pattern 35 (Fig 1c) exposed portions of the light-shielding layer 32 are etched by an etching glass plasma 36 (Fig 1d) to form a light-shielding pattern 37. The remaining resist 33 is incinerated by oxygen plasma 38 (Fig 1e) to form a photomask (Fig 1f). Next, a transparent film 39 is spin-coated over the pattern 37 (Fig 1g), and pattern-exposed to electron beam radiation 40 (Fig 1h), baked (Fig 1i) and developed to form a reticle bearing a phase shift pattern 41 (Fig 1j). The correction of defects in the phase shift layer is also disclosed.
Inventors
- 👤 Koichi c/o Dai Nippon Mikami
- 👤 Hiroyuki c/o Dai Nippon Miyashita
- 👤 Yoichi c/o Dai Nippon Takahashi
- 👤 Hiroshi c/o Dai Nippon Fujita
- 👤 Masa-aki c/o Dai Nippon Kurihara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 16:28
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/68; G03F1/72; H; H10; H10P; H10P76/00; G03F1/26; G03F1/29; G03F1/30
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
36 words
A phase shift layer-containing photomask, characterized in that the substrate to be processed is a photomask blank comprising a substrate material having formed thereon an electrically conductive layer and a light-shielding thin film, in that order.
Claim 2
Dependent Claim
65 words
A process for producing a phase shift layer-containing photomask, characterized in that the process comprises coating a starting material for spin-on-glass uniformly on a substrate, forming a pattern directly on the coated spin-on-glass layer with ionizing radiation, developing the substrate with a solvent after the pattern formation to wash off portions of the spin-on-glass layer other than the irradiated portions, and baking the developed substrate.
Claim 3
Dependent Claim
111 words
A process for correcting a phase shift layer-containing photomask, characterized in that the process comprises coating a starting material for spin-on-glass uniformly on a photomask containing a phase shift layer built up of a substrate, a light-shielding pattern and a phase shifter pattern, said phase shifter pattern being partly defective, heat-treating the photomask with the starting material for spin-on-glass coated thereon, irradiating the defective portion of the phase shift pattern with the starting material for spin-on-glass coated thereon with ionizing radiation commensurate with the geometry of said defective portion, developing the irradiated substrate with a solvent to wash off spin-on-glass portions other than the irradiated portions, and baking the developed substrate.
Claim 4
Dependent Claim
103 words
A process for producing a phase-shift layer-containing photomask by forming a thin resist film on a layer of phase-shift layer forming material coated on a substrate, forming a pattern on the thin resist film with ionizing radiation, developing the thin resist film to form a resist pattern, etching an exposed portion of the phase-shift layer using the resist pattern as a mask and removing the remainder of the resist after the completion of etching, characterized in that said pattern formation is carried out with the ionizing radiation after an electrically conductive thin film has been formed above or below said thin resist film.
Claim 5
Dependent Claim
35 words
A process as claimed in Claim 4, characterized in that said electrically conductive thin film is an electriccally conductive thin film obtained by spreading and depositing a Langmuir-Brodgett film over and onto said phase-shifting layer.
Claim 6
Dependent Claim
171 words
A process for producing a phase shift layer-containing photomask including a light-shielding pattern and a phase shifter for effecting a phase difference between transparent regions isolated from each other by a light-shielding region and located adjacent to each other, characterized in that said phase shifter is formed by the steps of forming, using an ionizing radiation resist, an ionizing radiation resist pattern on a portion commensurate with said phase shifter pattern on the surface of a substrate on which at least a light-shielding pattern and a transparent film of uniform thickness are provided, coating a photoresist over the whole surface of the substrate with the ionizing radiation resist pattern formed thereon and full-exposing the photoresist to light from the rear side of the substrate, thereby to form a photoresist pattern on at least a portion commensurate with the light-shielding pattern, and dry-etching the transparent film of uniform thickness using the photoresist pattern or the photoresist pattern plus the ionizing radiation resist pattern as a mask to form a phase shifter pattern.
Claim 7
Dependent Claim
42 words
A phase shift layer-containing photomask characterized in that it is formed, using as the photomask substrate to be processed, a photomask blank comprising a substrate material having provided thereon an etching stopper layer, a transparent film layer and a light-shielding thin film.
Claim 8
Dependent Claim
166 words
A process for producing a phase shift layer-containing photomask, characterized in that it comprises the steps of forming an ionizing radiation resist thin film on the substrate to be processed, which film comprises a substrate material having provided thereon an etching stopper layer, a transparent film layer and a light-shielding thin film in that order, irradiating the ionizing radiation resist thin film with ionizing radiation in a pattern and developing the film to form a pattern therein, etching an exposed portion of the light-shielding thin film using the formed ionizing radiation resist pattern as a mask, removing the remainder of the ionizing radiation resist thin film, forming a photoresist thin film on the thus patterned light-shielding thin film, exposing the photoresist thin film to light from the rear side of the glass substrate and developing it to form a pattern, side-etching the light-shielding thin film sandwiched between the photoresist thin film layer and the transparent film layer, and removing the photoresist after the completion of etching.
Claim 9
Dependent Claim
18 words
A process as claimed in Claim 2 or 3, wherein the starting material for spin-on-glass contains methyl groups.
Claim 10
Dependent Claim
19 words
A process as claimed in Claims 2 or 3, wherein the starting material for spin-on-glass contains an acid generator.
References Cited (Backward Citations)
No citation records indexed.
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