Patent US4259261A successfully refreshed from Google Patents.
Patent EP0271002A2 successfully refreshed from Google Patents.
EP0271002A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Transmittance modulation photomask, process for producing the same and process for producing diffraction grating
Assignee: Kuraray Co Ltd
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Filing: 1987-12-03
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Granted: —
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Expires: 2007-12-03
Abstract
Abstract The present invention provides a process for producing a blazed diffraction grating by using a transmission modulation diffraction grating as a photomask in photolithography. The photomask (5) is composed of a relief modulation diffraction grating (2) made of a transparent material and a blazed diffraction grating (4) made of a material containing a ray absorbing agent. The diffraction grating (2) and the diffraction grating (4) are mated with each other through their grating surfaces.
Inventors
- 👤 Nobuhiro Kawatsuki
- 👤 Katsuya Fujisawa
- 👤 Ichiro Matsuzaki
- 👤 Masao Uetsuki
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 17:38
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/54; G03F7/00; G03F7/0005; G03F7/001; G02; G02B; G02B5/00; G02B5/18; G02B5/1847; G02B5/1857; G03F1/50; H; H10; H10P; H10P76/00
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
49 words
A transmittance modulation photomask which comprises a first blazed diffraction grating made of a transparent material and a second blazed diffraction grating made of a material containing a ray absorbing agent, said first diffraction grating and said second diffraction grating mating with each other at their respective grating surfaces.
Claim 2
Dependent Claim
49 words
A transmittance modulation photomask which comprises a first blazed diffraction grating made of a transparent material and a second blazed diffraction grating made of a material containing a ray absorbing agent, said first diffraction grating and said second diffraction grating mating with each other at their respective grating surfaces.
Claim 3
Dependent Claim
36 words
A photomask as claimed in Claim 1 wherein the refractive index of the material constituting said first diffraction grating is at least approximately equal to the refractive index of the material constituting said second diffraction grating.
Claim 4
Dependent Claim
37 words
A photomask as claimed Claim 2 wherein the difference between the refractive index of the material constituting said first diffraction grating and the refractive index of the material constituting said second difrraction grating is smaller than 0.01.
Claim 5
Dependent Claim
18 words
A photomask as claimed in Claim 3 wherein the difference between the refractive indices is smaller than 0.001.
Claim 6
Dependent Claim
26 words
A photomask as claimed in Claims 1 to 4 wherein the upper and lower surfaces of the photomask are at least approximately parallel to each other.
Claim 7
Dependent Claim
25 words
A photomask as claimed in Claims 1 to 5 wherein the grating surfaces of said first and second diffraction gratings are serrate in cross section.
Claim 8
Dependent Claim
25 words
A photomask as claimed in Claims 1 to 5 wherein the grating surfaces of said first and second diffraction. gratings are curved in cross section.
Claim 9
Independent Claim
82 words
A method for producing a transmittance modulation photomask, in particular a photomask according to Claims 1 to 7, which comprises the steps of: (a) forming a first diffraction grating made of a transparent material and (b) forming a second diffraction grating made of a material having at least approximately the same refractive index as the material of which said first diffraction grating is made and containing a ray absorbing agent, said first and second diffraction gratings mating at their respective diffraction surfaces.
Claim 10
Dependent Claim
41 words
A method for producing a photomask as claimed in Claim 8 wherein the difference between refractive index of the material constituting said first diffraction grating and the refractive index of the material constituting said second diffraction grating is smaller than 0.01.
Claim 11
Dependent Claim
22 words
A method for producing a photomask as claimed in Claim 9 wherein the difference between the diffractive indices is smaller than 0.001.
Claim 12
Independent Claim
26 words
A method for producing a photomask as claimed in Claims 8 to 10 wherein the grating surface on said first diffraction grating is formed by cutting.
Claim 13
Independent Claim
26 words
A method for producing a photomask as claimed in Claims 8 to 10 wherein the grating surface on said first diffraction grating is formed by photolithography.
Claim 14
Dependent Claim
34 words
A method for producing a photomask as claimed in Claim 12 wherein the grating surface on said first diffraction grating is formed by drawing directly on a photoresist on the substrate by changing dose.
Claim 15
Dependent Claim
30 words
A method for producing a photomask as claimed in Claim 12 wherein the grating surface on said first diffraction grating is formed directly by the asymmetric double-beam interference exposure method.
Claim 16
Dependent Claim
65 words
A method for producing a photomask as claimed in Claim 8 wherein said first diffraction grating is formed by the steps of: (a) forming a layer of photosensitive resin on a substrate; (b) forming the grating surface on said photosensitive resin by exposure and photolithographic development; and (c) transferring the grating surface to the substrate by dry etching using said grating surface as a photomask.
Claim 17
Dependent Claim
25 words
A method for producing a photomask as claimed in Claim 15 wherein the substrate is formed by coating a glass plate with a transparent material.
Claim 18
Dependent Claim
30 words
A method for producing a photomask as claimed in Claim 15 wherein the substrate is formed by coating a glass plate with a transparent material containing a light absorbing agent.
Claim 19
Independent Claim
22 words
A method for producing a photomask as claimed in Claims 15 to 17 wherein the transfer is accomplished by oxygen plasma etching.
Claim 20
Dependent Claim
22 words
A method for producing a photomask as claimed in Claim 18 wherein the light absorbing agent is an ultraviolet light absorbing agent.
Claim 21
Independent Claim
86 words
A method for producing a diffraction grating which comprises the steps of: (a) forming a layer of photosensitive resin on a substrate; (b) tightly placing a transmittance modulation photomask composed of a first blazed diffraction grating made of a transparent material and a second blazed diffraction grating made of a material containing a ray absorbing agent, said first diffraction grating and said second diffraction grating mating with each other at their respective surfaces; and (c) subjecting the layer of the photosensitive resin to exposure and development.
Claim 22
Independent Claim
86 words
A method for producing a diffraction grating which comprises the steps of: (a) forming a layer of photosensitive resin on a substrate; (b) tightly placing a transmittance modulation photomask composed of a first blazed diffraction grating made of a transparent material and a second blazed diffraction grating made of a material containing a ray absorbing agent, said first diffraction grating and said second diffraction grating mating with each other at their respective surfaces; and (c) subjecting the layer of the photosensitive resin to exposure and development.
Claim 23
Dependent Claim
72 words
A method for producing a diffraction grating as claimed in Claim 20 wherein the photosensitive resin is one which has a relationship between the dose (amount of exposure) and the ratio residual film after exposure and development which is at least approximately identical to the relationship between the thickness of the ray absorbing agent and the light-transmittance possessed by the light absorbing agent of said blazed diffraction unit used as a photomask.
Claim 24
Dependent Claim
41 words
A method for producing a diffraction grating as claimed in Claim 20 wherein the refractive index of the material constituting said first diffraction grating is at least approximately equal to the refractive index of the material constituting said second diffraction grating.
Claim 25
Dependent Claim
23 words
A method for producing a diffraction grating as claimed in Claim 22 wherein the difference between the refractive indices is smaller than 0.01.
Claim 26
Dependent Claim
23 words
A method for producing a diffraction grating as claimed in Claim 23 wherein the difference between the refractive indices is smaller than 0.001.
Claim 27
Independent Claim
32 words
A method for producing a diffraction grating as claimed in Claims 20 to 24 wherein the photomask has smooth upper and lower surfaces which are at least approximately parallel to each other.
Claim 28
Independent Claim
24 words
A method for producing a diffraction grating as claimed in Claims 20 to 25 wherein the ray absorbing agent is an ultraviolet ray absorber.
Claim 29
Dependent Claim
13 words
A diffraction grating producible by the method according to Claims 20 to 26.
References Cited (Backward Citations)
No citation records indexed.
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