EP0453310A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Mask for photolithography
Assignee: Sharp Corp
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Filing: 1991-04-19
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Granted: —
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Expires: 2011-04-19
Abstract
Abstract A mask for photolithography having a transparent substrate (1) which allows light having a predetermined wavelength to pass therethrough; an opaque pattern (4) provided on said substrate for inhibiting the light from passing therethrough; and a stepped portion (6) provided adjacent to said opaque pattern on said substrate and having an inclined area, said stepped portion being transparent for allowing the light to pass therethrough, which can be used in a photolithographic system in fabrication of semiconductor devices and the like.
Inventors
- 👤 Katsuji Iguchi
- 👤 Takashi Fukushima
- 👤 Hiroki Tabuchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 00:10
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/26; G03F1/29
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
62 words
A mask for photolithography comprising: a transparent substrate which allows light having a predetermined wavelength to pass therethrough; an opaque pattern provided on said substrate for inhibiting the light from passing therethrough; and a stepped portion provided adjacent to said opaque pattern on said substrate and having an inclined area, said stepped portion being transparent for allowing the light to pass therethrough.
Claim 2
Dependent Claim
65 words
A mask as claimed in claim 1 wherein said stepping portion is formed by a method comprising a step for forming a side wall at the end of said opaque pattern to be vertical relative to said substrate and a step for depositing or applying a transparent film on at least said side wall to form said stepping portion shaped like approximately a quarter arc.
Claim 3
Dependent Claim
74 words
A mask as claimed in claim 1 wherein said stepping portion is formed by a method comprising a step for forming a side wall at the end of said opaque pattern to be vertical relative to said substrate and a step for depositing or applying a transparent film on said substrate having said opaque pattern to form, on the upper portion of said opaque pattern, said stepping portion shaped like approximately a quarter arc.
Claim 4
Dependent Claim
24 words
A mask as claimed in claim 1 wherein said stepping portion is formed by etching the substrate at the portion surrounding said opaque pattern.
Claim 5
Dependent Claim
50 words
A mask as claimed in claim 1 wherein said stepping portion is formed by etching the substrate at the portion surrounding said opaque pattern to be vertical to said substrate, said stepping portion shaped like approximately a quarter arc by depositing a transparent film on at least said stepping portion.
Claim 6
Dependent Claim
31 words
A mask as claimed in claim 1 wherein said stepping portion is formed by etching said substrate at the portion surrounding said opaque pattern so as to form an inclined area.
Claim 7
Dependent Claim
29 words
A mask as claimed in claim 1 wherein said opaque pattern is formed of a single opaque film or a combination of an opaque film and a transparent film.
Claim 8
Dependent Claim
46 words
A mask as claimed in claim 1 wherein said opaque pattern is formed of one or more films selected among a metal film such as tungsten, chromium, cobalt, nickel or aluminum, a silicon metal compound film or a semiconductor film such as silicon alloy or silicon.
Claim 9
Dependent Claim
29 words
A mask as claimed in claim 3 wherein a film thickness of said opaque pattern is approximately equal to that of said transparent film for forming said stepping portion.
Claim 10
Dependent Claim
14 words
A mask as claimed in claim 1 wherein said substrate is made of quartz.
Claim 11
Dependent Claim
153 words
A process for manufacturing a mask for photolighography on a transparent substrate which allows light having a predetermined wavelength to pass therethrough, said process comprising: (1) a step for forming a shield film which inhibits the light from passing therethrough; (2) a step for forming a resist film to electron beam on said shield film; (3) a step for forming a resist pattern on said resist film by drawing a predetermined pattern with an electron beam lithographic apparatus and then developing thus formed pattern; (4) a step for forming a stepping portion around said resist pattern by etching said shield pattern with said resist pattern served as a mask by anisotropic etching; and (5) a step for laminating, on said substrate including said opaque pattern, by removing or without removing said resist pattern, whereby said stepping portion is made transparent for allowing the light to pass therethrough and to have an inclined area.
Claim 12
Dependent Claim
36 words
A process for preparing a mask for photolithography as claimed in claim 11 wherein said laminated transparent film is removed except for the portion surrounding said resist pattern after the step of (5) in claim 11.
Claim 13
Dependent Claim
153 words
A process for manufacturing a mask for photolighography on a transparent substrate which allows light having a predetermined wavelength to pass therethrough, said process comprising: (1) a step for forming a shield film which inhibits the light from passing therethrough; (2) a step for forming a resist film to electron beam on said shield film; (3) a step for forming a resist pattern on said resist film by drawing a predetermined pattern with an electron beam lithographic apparatus and then developing thus formed pattern; (4) a step for forming a stepping portion around said resist pattern by etching said substrate with said resist pattern served as a mask by reactive etching; and (5) a step for depositing said transparent film on said substrate when said stepping portion is formed vertical to said substrate, whereby said stepping portion is made transparent for allowing the light to pass therethrough and to have an inclined area.
Claim 14
Dependent Claim
86 words
A mask for photolithorgraphy, comprising a substrate which is transparent to radiation of a predetermined wavelength and on which is formed a pattern of opaque portions for blocking said radiation, transparent means being provided for introducing phase shift in the transmitted light in regions adjacent the edges of the opaque portions to improve resolution in a photolithographic process employing the mask, characterised in that said transparent phase-shifting means comprises transparent material portions formed without patterning and having surface portions which slope with respect to the substrate.
References Cited (Backward Citations)
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