U.S. patent application number 17/603932 was filed with the patent office on 2022-07-07 for agglutinant for pellicle, pellicle, exposure original plate with pellicle, method for producing semiconductor device, method for producing liquid crystal display board, method for regenerating exposure original plate, and peeling residue reduction method.
This patent application is currently assigned to Shin-Etsu Chemical Co., Ltd.. The applicant listed for this patent is Shin-Etsu Chemical Co., Ltd.. Invention is credited to Yuichi Hamada, Akinori Nishimura.
Application Number | 20220214612 17/603932 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-07 |
United States Patent
Application |
20220214612 |
Kind Code |
A1 |
Hamada; Yuichi ; et
al. |
July 7, 2022 |
Agglutinant for Pellicle, Pellicle, Exposure Original Plate with
Pellicle, Method for Producing Semiconductor Device, Method for
Producing Liquid Crystal Display Board, Method for Regenerating
Exposure Original Plate, and Peeling Residue Reduction Method
Abstract
Provided is an agglutinant for pellicles that can reduce
residues stuck onto an exposure original plate when a pellicle is
peeled from the exposure original plate after being used in
lithography, in particular ArF lithography, and also provided are a
pellicle, an exposure original plate with a pellicle, a method for
regenerating an exposure original plate, and a peeling residue
reduction method. An agglutinant for pellicles for bonding a
pellicle to an exposure original plate, in which the agglutinant
includes an acrylic polymer having an SP value of 10.0 or more and
12.0 or less as a base material.
Inventors: |
Hamada; Yuichi; (Annaka-shi,
Gunma-ken, JP) ; Nishimura; Akinori; (Annaka-shi,
Gunma-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Shin-Etsu Chemical Co., Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Shin-Etsu Chemical Co.,
Ltd.
Tokyo
JP
|
Appl. No.: |
17/603932 |
Filed: |
April 15, 2020 |
PCT Filed: |
April 15, 2020 |
PCT NO: |
PCT/JP2020/016626 |
371 Date: |
October 14, 2021 |
International
Class: |
G03F 1/64 20060101
G03F001/64; G03F 1/66 20060101 G03F001/66; G03F 7/20 20060101
G03F007/20 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 16, 2019 |
JP |
2019-077837 |
Apr 23, 2019 |
JP |
2019-082301 |
Apr 23, 2019 |
JP |
2019-082302 |
Claims
1. An agglutinant for pellicles for bonding a pellicle to an
exposure original plate, the agglutinant comprising an acrylic
polymer having an SP value of 10.0 or more and 12.0 or less as a
base material.
2. An agglutinant for pellicles for bonding a pellicle to an
exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer comprising a
(meth)acrylic acid ester having an ether bond as a monomer
component.
3. An agglutinant for pellicles as claimed in claim 2, wherein the
(meth)acrylic acid ester having an ether bond is a (meth)acrylic
acid ester having an alkylene oxide group.
4. An agglutinant for pellicles as claimed in claim 3, wherein the
(meth)acrylic acid ester having an ether bond is contained in an
amount of 30 mass % or more based on the whole monomer
components.
5. An agglutinant for pellicles as claimed in claim 3, wherein the
alkylene oxide group is an ethylene oxide group.
6. An agglutinant for pellicles as claimed in claim 2, further
comprising an unsaturated monomer having a carboxyl group or a
hydroxyl group as a monomer component.
7. An agglutinant for pellicles as claimed in claim 2, further
comprising a (meth)acrylic acid alkyl ester as a monomer
component.
8. An agglutinant for pellicles for bonding a pellicle to an
exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
containing an ether bond.
9. An agglutinant for pellicles as claimed in claim 8, wherein the
side chain containing an ether bond has an alkylene oxide
group.
10. An agglutinant for pellicles as claimed in claim 9, wherein the
alkylene oxide group is an ethylene oxide group.
11. An agglutinant for pellicles for bonding a pellicle to an
exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
that has higher degradability by irradiation with an exposure light
beam than a main chain.
12. An agglutinant for pellicles for bonding a pellicle to an
exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
that is selectively degraded by irradiation with an exposure light
beam.
13. A pellicle frame with an agglutinant layer, comprising a
pellicle frame and an agglutinant layer provided on one end face of
the pellicle frame and obtained from an agglutinant for pellicles
as claimed in claim 1.
14. A pellicle comprising a pellicle film, a pellicle frame
provided with the pellicle film on one end face thereof, and an
agglutinant layer provided on the other end face of the pellicle
frame and obtained from an agglutinant for pellicles as claimed in
claim 1.
15. A pellicle as claimed in claim 14, wherein the agglutinant
layer is irradiated with an exposure light beam.
16. A pellicle as claimed in claim 14, wherein the pellicle is
bonded to a phase shift photo mask.
17. A pellicle as claimed in claim 14, wherein the pellicle is
bonded to a negative type exposure original plate.
18. A pellicle as claimed in claim 14, wherein the pellicle is
bonded to an exposure original plate that has a non-shaded area or
a semi-transparent shaded area in a portion thereof to which an
agglutinant layer is bonded.
19. A pellicle as claimed in claim 14, wherein the pellicle is
bonded to an exposure original plate that has a transparent area in
a portion thereof to which an agglutinant layer is bonded.
20. A pellicle as claimed in claim 14, wherein the pellicle is
bonded to a face comprising silicon oxide as a main component.
21. A pellicle as claimed in claim 20, wherein the face comprising
silicon oxide as a main component is a quartz face.
22. A pellicle as claimed in claim 14, wherein the pellicle is
compatible with regeneration cleaning with functional water.
23. An exposure original plate with a pellicle, comprising an
exposure original plate and a pellicle as claimed in claim 14
mounted on the exposure original plate.
24. An exposure original plate with a pellicle as claimed in claim
23, wherein the exposure original plate is a phase shift photo
mask.
25. An exposure original plate with a pellicle as claimed in claim
23, wherein the exposure original plate is of negative type.
26. An exposure original plate with a pellicle as claimed in claim
23, wherein a portion of the exposure original plate to which the
agglutinant layer is bonded has a non-shaded area or a
semi-transparent shaded area.
27. An exposure original plate with a pellicle as claimed in claim
23, wherein a portion of the exposure original plate to which the
agglutinant layer is bonded has a transparent area.
28. An exposure original plate with a pellicle as claimed in claim
23, wherein the exposure original plate comprises silicon oxide as
a main component.
29. An exposure original plate with a pellicle as claimed in claim
23, wherein the exposure original plate is a quartz substrate.
30. A method for producing a semiconductor device, comprising a
step of performing exposure using an exposure original plate with a
pellicle as claimed in claim 23.
31. A method for producing a liquid crystal display board,
comprising a step of performing exposure using an exposure original
plate with a pellicle as claimed in claim 23.
32. A method for regenerating an exposure original plate,
comprising peeling a pellicle from an exposure original plate with
a pellicle as claimed in claim 23, and cleaning residues of an
agglutinant remaining on the exposure original plate with
functional water to regenerate the exposure original plate.
33. A peeling residue reduction method comprising, when peeling a
pellicle from an exposure original plate to which the pellicle is
bonded, reducing peeling residues of an agglutinant layer of the
pellicle remaining on the exposure original plate, wherein the
method uses a pellicle as claimed in claim 14 as the pellicle.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an agglutinant for
pellicles, a pellicle, an exposure original plate with a pellicle,
a method for producing a semiconductor device, a method for
producing a liquid crystal display board, a method for regenerating
an exposure original plate, and a peeling residue reduction
method.
TECHNICAL BACKGROUND OF THE INVENTION
[0002] In manufacturing semiconductor devices such as LSI and
super-LSI or in manufacturing a liquid crystal display board or the
like, a pattern is made by irradiating light to a semiconductor
wafer or an original plate for liquid crystal, but if dust is
attached to an exposure original plate used in this case, the dust
absorbs the light or bends the light. As a result, the transferred
pattern would be deformed, and the resulting pattern would have
roughened edges or black stains on the base, which would lead to
problems such as damaged dimensions, poor quality, and deformed
external appearance. In the present invention, the "exposure
original plate" is a generic name of lithography masks and
reticles.
[0003] These works are usually performed in a cleanroom, but it is
difficult to keep the exposure original plate clean all the time
even in the cleanroom. Therefore, a pellicle that transmits light
for exposure well is bonded to a surface of the exposure original
plate as a dust-fender.
[0004] Under such circumstances, the dust does not directly adhere
to the surface of the exposure original plate but adhere only to
the pellicle film. Accordingly, when the focus is set on the
pattern of the exposure original plate during lithography, the dust
on the pellicle film becomes irrelevant to transfer.
[0005] The basic structure of the pellicle comprises a pellicle
frame and a pellicle film stretched over the pellicle frame. The
pellicle film is made of nitrocellulose, cellulose acetate, a
fluorine-based polymer, or the like that well transmits light used
for exposure (g-rays, i-rays, 248 nm, 193 nm, 157 nm, etc.). The
pellicle frame is made of an aluminum alloy such as A7075, A6061,
or A5052 treated with black alumite or the like, stainless steel,
polyethylene, or the like. A good solvent of a pellicle film is
applied to the upper part of the pellicle frame, and the pellicle
film is bonded by air-drying or using an adhesive material such as
an acrylic resin, an epoxy resin, or fluororesin. Further, since
the lower part of the pellicle frame is mounted with an exposure
original plate, an agglutinant layer obtained from a polybutene
resin, a polyvinyl acetate resin, an acrylic resin, a silicone
resin, or the like, and a protective liner for protecting the
agglutinant layer are provided.
[0006] The pellicle is provided so as to surround a pattern region
formed on the surface of the exposure original plate. Since the
pellicle is provided to prevent the adhesion of dust to the
exposure original plate, the pattern region and the outside of the
pellicle are isolated from each other so that dust from the outside
of the pellicle does not adhere to the pattern surface.
[0007] In recent years, miniaturization of LSI design rules to
sub-quarter microns has progressed. Along with this, the wavelength
of exposure light sources is becoming shorter. That is, the trend
is moving from g-rays (436 nm) and i-rays (365 nm) produced by
mercury lamps, which have been the mainstream until now, to KrF
excimer laser (248 nm), ArF excimer laser (193 nm), F.sub.2 laser
(157 nm), and the like. As a result of progress in miniaturization,
the allowable size of foreign substances and haze that may be
generated on the pattern face of the mask substrate to which the
pellicle is bonded is becoming more and more strict.
PRIOR ART PUBLICATIONS
Publications
[0008] IP Publication 1: Japanese Patent No. 5638693 [0009] IP
Publication 2: Japanese Patent Application Publication No.
2016-18008 [0010] IP Publication 3: Japanese Patent Application
Publication No. 2006-146085 [0011] IP Publication 4: Japanese
Patent Application Publication No. 2008-21182
SUMMARY OF THE INVENTION
Problems the Invention Seeks to Solve
[0012] In recent years, phase shift films have been commonly used
as mask substrate films to meet the miniaturization of design
rules. However, phase shift films are very delicate, and mask
cleaning under excessive conditions may cause damage, such as
corrosion and scraping, to the phase shift films. For this reason,
in recent years, there has been a tendency to reconsider chemicals
used for mask cleaning, and to weaken the cleaning conditions.
[0013] Furthermore, the mask pattern of advanced mask products is
shifting from positive type mask patterns, which have been the
mainstream until now, to negative type mask patterns. As a result,
there are many situations where no light-shading layer is provided
in the portion to which the pellicle is bonded. If there is no
light-shading layer, there is a possibility that the pellicle
agglutinant is irradiated with an exposure light beam through the
mask substrate. In that case, more residues of the agglutinant
layer may remain on the mask substrate when the pellicle is
peeled.
[0014] During use of a pellicle bonded to a mask, if foreign
substances and haze are generated, or if the pellicle film is
damaged, it is necessary to peel the pellicle, subject the mask to
regeneration cleaning, and bond a new pellicle (which is
hereinafter referred to as "repellicle"). It is the most important
for repellicle that regeneration cleaning is performed so that the
mask is kept in a state of high cleanliness; however, in order to
carry out regeneration cleaning of the mask under recent weak
cleaning conditions, it is important to reduce residues remaining
on the mask substrate when the pellicle is peeled.
[0015] As regeneration cleaning, cleaning with chemicals such as
sulfuric acid hydrogen peroxide or ammonia hydrogen peroxide, and
physical cleaning by brushes, sponges, or the like are generally
used. However, regeneration cleaning with functional water is being
studied to prevent damage to photo masks and sulfate ions from
remaining on the photo masks.
[0016] Functional water is generally defined by the Japanese
Society for Functional Water as, among aqueous solutions that have
been given reproducible and useful functions by artificial
treatment, those for which the scientific basis for treatment and
function has been clarified, and those for which such scientific
basis is about to be clarified. Specific examples thereof include
fine bubble water such as ozone water, hydrogen water, micro-bubble
water, and nano-bubble water; electrolyzed water, supercritical
water, subcritical water, and the like. Ozone water and hydrogen
water are often used to clean photo masks. In addition, the
cleaning power can be improved by adding a small amount of
ammonia.
[0017] However, the present inventors found that since the cleaning
power of functional water was weaker than that of chemicals such as
sulfuric acid hydrogen peroxide, in the regeneration cleaning of
the photo mask after the removal of the pellicle, residues of the
agglutinant layer that fixed the pellicle and the photo mask were
difficult to remove only by functional water cleaning. In
particular, in phase shift photo masks, damage to phase shift films
leads to changes in transmittance and phase difference, and it is
thus difficult to add physical cleaning in addition to functional
water cleaning.
[0018] Moreover, when lithography is performed using an exposure
light beam such as ArF excimer laser (193 nm) on a lithography
pellicle in which a pellicle film is stretched over the upper end
face of a pellicle frame through a pellicle film bonding adhesive
material layer, and in which a mask bonding agglutinant layer is
provided on the other end face, there is a problem that the
agglutinant layer formed on the lower end face of the pellicle
frame is altered by the exposure light beam, and many altered parts
of the agglutinant layer remain on the exposure original plate as
peeling residues when peeling from the exposure original plate.
[0019] Attempts have been made so far to reduce residues by adding
surface modifiers or the like to agglutinants (IP Publications 1
and 2 described above). Further, as techniques of reducing
residues, a large pellicle having an agglutinant layer with a
cohesive fracture strength of 20 g/mm.sup.2 or more (IP Publication
3 described above), and a pellicle comprising an agglutinant for
pellicles and having a ratio of peeling strength and tensile
strength of 0.10 or more and 0.33 or less are disclosed (IP
Publication 4 described above).
[0020] The present invention was made in view of such
circumstances, and an object of the present invention is to provide
an agglutinant for pellicles that can reduce residues stuck onto an
exposure original plate when a pellicle is peeled from the exposure
original plate after being used in lithography, in particular ArF
lithography, and to also provide a pellicle, an exposure original
plate with a pellicle, a method for regenerating an exposure
original plate, and a peeling residue reduction method. Another
object of the present invention is to provide a method for
producing a semiconductor device and a method for producing a
liquid crystal display board that can thereby improve production
efficiency.
Means to Solve the Problems
[0021] [1] An agglutinant for pellicles for bonding a pellicle to
an exposure original plate, the agglutinant comprising an acrylic
polymer having an SP value of 10.0 or more and 12.0 or less as a
base material.
[0022] [2] An agglutinant for pellicles for bonding a pellicle to
an exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer comprising a
(meth)acrylic acid ester having an ether bond as a monomer
component.
[0023] [3] An agglutinant for pellicles as claimed in [2] described
above, wherein the (meth)acrylic acid ester having an ether bond is
a (meth)acrylic acid ester having an alkylene oxide group.
[0024] [4] An agglutinant for pellicles as claimed in [3] described
above, wherein the (meth)acrylic acid ester having an ether bond is
contained in an amount of 30 mass % or more based on the whole
monomer components.
[0025] [5] An agglutinant for pellicles as claimed in [3] or [4]
described above, wherein the alkylene oxide group is an ethylene
oxide group.
[0026] [6] An agglutinant for pellicles as claimed in any one of
[2] to [5] described above, further comprising an unsaturated
monomer having a carboxyl group or a hydroxyl group as a monomer
component.
[0027] [7] An agglutinant for pellicles as claimed in any one of
[2] to [6] described above, further comprising a (meth)acrylic acid
alkyl ester as a monomer component.
[0028] [8] An agglutinant for pellicles for bonding a pellicle to
an exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
containing an ether bond.
[0029] [9] An agglutinant for pellicles as claimed in [8] described
above, wherein the side chain containing an ether bond has an
alkylene oxide group.
[0030] [10] An agglutinant for pellicles as claimed in [9]
described above, wherein the alkylene oxide group is an ethylene
oxide group.
[0031] [11] An agglutinant for pellicles for bonding a pellicle to
an exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
that has higher degradability by irradiation with an exposure light
beam than a main chain.
[0032] [12] An agglutinant for pellicles for bonding a pellicle to
an exposure original plate, the agglutinant comprising an acrylic
polymer as a base material, the acrylic polymer having a side chain
that is selectively degraded by irradiation with an exposure light
beam.
[0033] [13] A pellicle frame with an agglutinant layer, comprising
a pellicle frame and an agglutinant layer provided on one end face
of the pellicle frame and obtained from an agglutinant for
pellicles as claimed in any one of [1] to [12] described above.
[0034] [14] A pellicle comprising a pellicle film, a pellicle frame
provided with the pellicle film on one end face thereof, and an
agglutinant layer provided on the other end face of the pellicle
frame and obtained from an agglutinant for pellicles as claimed in
any one of [1] to [12] described above.
[0035] [15] A pellicle as claimed in [14] described above, wherein
the agglutinant layer is irradiated with an exposure light
beam.
[0036] [16] A pellicle as claimed in [14] described above, wherein
the pellicle is bonded to a phase shift photo mask.
[0037] [17] A pellicle as claimed in [14] described above, wherein
the pellicle is bonded to a negative type exposure original
plate.
[0038] [18] A pellicle as claimed in [14] described above, wherein
the pellicle is bonded to an exposure original plate that has a
non-shaded area or a semi-transparent shaded area in a portion
thereof to which an agglutinant layer is bonded.
[0039] [19] A pellicle as claimed in [14] described above, wherein
the pellicle is bonded to an exposure original plate that has a
transparent area in a portion thereof to which an agglutinant layer
is bonded.
[0040] [20] A pellicle as claimed in [14] described above, wherein
the pellicle is bonded to a face comprising silicon oxide as a main
component.
[0041] [21] A pellicle as claimed in [20] described above, wherein
the face comprising silicon oxide as a main component is a quartz
face.
[0042] [22] A pellicle as claimed in [14] described above, wherein
the pellicle is compatible with regeneration cleaning with
functional water.
[0043] [23] An exposure original plate with a pellicle, comprising
an exposure original plate and a pellicle as claimed in [14] or
[15] described above mounted on the exposure original plate.
[0044] [24] An exposure original plate with a pellicle as claimed
in [23] described above, wherein the exposure original plate is a
phase shift photo mask.
[0045] [25] An exposure original plate with a pellicle as claimed
in [23] described above, wherein the exposure original plate is of
negative type.
[0046] [26] An exposure original plate with a pellicle as claimed
in [23] described above, wherein a portion of the exposure original
plate to which the agglutinant layer is bonded has a non-shaded
area or a semi-transparent shaded area.
[0047] [27] An exposure original plate with a pellicle as claimed
in [23] described above, wherein a portion of the exposure original
plate to which the agglutinant layer is bonded has a transparent
area.
[0048] [28] An exposure original plate with a pellicle as claimed
in [23] described above, wherein the exposure original plate
comprises silicon oxide as a main component.
[0049] [29] An exposure original plate with a pellicle as claimed
in [23] described above, wherein the exposure original plate is a
quartz substrate.
[0050] [30] A method for producing a semiconductor device,
comprising a step of performing exposure using an exposure original
plate with a pellicle as claimed in any one of [23] to [29]
described above.
[0051] [31] A method for producing a liquid crystal display board,
comprising a step of performing exposure using an exposure original
plate with a pellicle as claimed in any one of [23] to [29]
described above.
[0052] [32] A method for regenerating an exposure original plate,
comprising peeling a pellicle from an exposure original plate with
a pellicle as claimed in any one of [23] to [29] described above,
and cleaning residues of an agglutinant remaining on the exposure
original plate with functional water to regenerate the exposure
original plate.
[0053] [33] A peeling residue reduction method comprising, when
peeling a pellicle from an exposure original plate to which the
pellicle is bonded, reducing peeling residues of an agglutinant
layer of the pellicle remaining on the exposure original plate,
wherein the method uses a pellicle as claimed in any one of [14] to
[22] described above as the pellicle.
[0054] [34] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the agglutinant layer is irradiated with an
exposure light beam.
[0055] [35] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is bonded to a phase shift photo
mask.
[0056] [36] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is bonded to a negative type
exposure original plate.
[0057] [37] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is bonded to an exposure original
plate that has a non-shaded area or a semi-transparent shaded area
in a portion thereof to which the agglutinant layer is bonded.
[0058] [38] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is bonded to an exposure original
plate that has a transparent area in a portion thereof to which the
agglutinant layer is bonded.
[0059] [39] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is bonded to a face comprising
silicon oxide as a main component (in particular, a quartz
face).
[0060] [40] An application of a pellicle comprising a pellicle
film, a pellicle frame provided with the pellicle film on one end
face thereof, and an agglutinant layer provided on the other end
face of the pellicle frame and obtained from an agglutinant for the
pellicle, wherein the pellicle is compatible with regeneration
cleaning with functional water.
[0061] [41] A peeling residue reduction pellicle comprising a
pellicle film, a pellicle frame provided with the pellicle film
bonded to one end face thereof, and an agglutinant layer for
bonding the pellicle provided on the other end face of the pellicle
frame to an exposure original plate, wherein the agglutinant layer
comprises an acrylic resin having an SP value of 10.0 or more and
12.0 or less as a base material.
[0062] [42] A peeling residue reduction pellicle as claimed in [41]
described above, wherein the agglutinant layer further contains a
polyvinyl ether compound.
[0063] [43] A peeling residue reduction pellicle as claimed in [41]
or [42] described above, wherein the peeling residue reduction
pellicle is a peeling residue reduction pellicle for ArF
lithography.
[0064] [44] A method for producing a peeling residue reduction
pellicle, the method comprising selecting an agglutinant for
bonding the pellicle to an exposure original plate, applying the
agglutinant to one end face of a pellicle frame to form an
agglutinant layer, peelably bonding a protective member thereto,
applying an adhesive material to the other end face of the pellicle
frame, and bonding a pellicle film thereto, wherein in selection of
the agglutinant, one comprising an acrylic resin having an SP value
of 10.0 or more and 12.0 or less as a base material is
selected.
[0065] [45] A method for producing a peeling residue reduction
pellicle as claimed in [44] described above, wherein the
agglutinant layer further contains a polyvinyl ether compound.
[0066] [46] A method for reducing, when a pellicle is peeled from
an exposure original plate to which the pellicle is bonded, peeling
residues of an agglutinant layer of the pellicle remaining on the
exposure original plate, wherein the method uses a pellicle as
claimed in any one of [41] to [43] described above as the
pellicle.
Effects of the Invention
[0067] The present invention can provide a pellicle that can reduce
peeling residues stuck onto an exposure original plate when a
pellicle is peeled from the exposure original plate after being
used in lithography, in particular ArF lithography, and can also
provide an exposure original plate with a pellicle, a method for
regenerating an exposure original plate, and a peeling residue
reduction method. According to the pellicle, exposure original
plate with a pellicle, method for regenerating an exposure original
plate, and peeling residue reduction method of the present
invention, even when an exposure light beam is applied through the
exposure original plate, the pellicle can be peeled from the
exposure original plate with very few peeling residues of the
agglutinant. As a result, the regeneration cleaning of the exposure
original plate, from which the pellicle is removed, can proceed
smoothly, and the cleaning conditions can be loosened; thus, there
is an advantage in reducing damage to the exposure original plate
surface during cleaning. In addition, production efficiency can be
improved in the production of semiconductor devices and liquid
crystal display boards.
[0068] In the pellicle of the present invention, it is assumed that
since a specific acrylic polymer (also referred to as an acrylic
resin) is used as the base material of the agglutinant, the
intermolecular force inside the agglutinant is improved,
appropriate adhesive strength can be maintained, and not only large
residues but also particulate residues are reduced during peeling
from the exposure original plate.
BRIEF DESCRIPTION OF DRAWINGS
[0069] FIG. 1 A conceptual diagram showing the basic structure of
the pellicle of the present invention.
EXAMPLES TO EMBODY THE INVENTION
[0070] First, the basic structure of the pellicle of the present
invention will be described with reference to FIG. 1.
[0071] As shown in FIG. 1, the pellicle 10 of the present invention
is such that a pellicle film 12 is stretched over the upper end
face of a pellicle frame 11 through an adhesive material layer 13
for bonding the pellicle film. In this case, an agglutinant layer
14 for bonding the pellicle 10 to an exposure original plate (mask
substrate or reticle) 1 is generally formed on the lower end face
of the pellicle frame 11, and a liner (not shown) is peelably
bonded to the lower end face of the agglutinant layer 14. In
addition, the pellicle frame 11 may be provided with an air
pressure adjustment hole (vent) 15, and may be further provided
with a dust removal filter 16 for the purpose of removing
particles.
[0072] In this case, the size of these pellicle constituent members
is equivalent to that of general pellicles, for example, pellicles
for semiconductor lithography and pellicles for the lithography
step in the production of large liquid crystal display boards.
Moreover, the materials thereof can be known materials as described
above.
[0073] The type of pellicle film 12 is not particularly limited.
For example, amorphous fluoropolymers conventionally used for
excimer laser are used. Examples of amorphous fluoropolymers
include Cytop (trade name of AGC Inc.), Teflon (registered
trademark) AF (trade name of DuPont), and the like. These polymers
may be used after being dissolved in solvents, if necessary, during
the production of pellicle films, and can be suitably dissolved,
for example, in fluorine type solvents.
[0074] As for the base material of the pellicle frame 11, for
example, aluminum alloy materials, preferably JIS A7075, JIS A6061,
and JIS A5052 materials, are used. When an aluminum alloy material
is used, there is no particular limitation as long as the strength
as the pellicle frame is ensured. The pellicle frame surface is
preferably roughened by sandblasting or chemical polishing, and a
polymer coating may be provided after roughening. In the present
invention, a conventionally known method can be employed as the
method for roughening the frame surface. In a preferable method,
the surface of an aluminum alloy material is subjected to blast
treatment using stainless steel, carborundum, glass beads, or the
like, and is further subjected to chemical polishing using NaOH or
the like, thereby roughening the surface.
[0075] By the way, the present inventors conducted many discussions
and experiments in order to solve the above problems of the present
invention, particularly focused on the feature of the agglutinant
forming the agglutinant layer, and comparatively analyzed the
experimental results. As a result, the present inventors found that
the following means was effective.
[0076] That is, a first aspect of the agglutinant for pellicles of
the present invention is to use an acrylic polymer having an SP
value of 10.0 or more and 12.0 or less as a base material. Due to
the acrylic polymer having an SP value of 10.0 or more and 12.0 or
less, when the pellicle is peeled from the exposure original plate,
peeling residues of the agglutinant layer remaining on the exposure
original plate can be reduced. When the SP value is 10.0 or more,
residues that can hardly be removed by cleaning can be reduced. On
the other hand, when the SP value is 12.0 or less, the volatility
of the agglutinant can be reduced, which leads to the suppression
of haze. The present inventors assume that the effects of the
present invention can be obtained by improving the hydrophilicity
of the acrylic polymer by setting the SP value within the specific
range.
[0077] A second aspect of the agglutinant for pellicles of the
present invention is to use, as a base material, an acrylic polymer
comprising a (meth)acrylic acid ester having an ether bond as a
monomer component. Because a (meth)acrylic acid ester having an
ether bond is contained as a monomer component of an acrylic
polymer, when the pellicle is peeled from the exposure original
plate, peeling residues of the agglutinant layer remaining on the
exposure original plate can be reduced. Due to the introduction of
an ether bond into an acrylic polymer, it becomes easy to control
the hydrophilicity of the acrylic polymer. In addition, due to the
introduction of an ether bond into the side chain of an acrylic
polymer, the ether bond is assumed to prevent light-deterioration
of the main chain.
[0078] A third aspect of the agglutinant for pellicles of the
present invention is to use, as a base material, an acrylic polymer
having a side chain containing an ether bond. Because an ether bond
is contained in the side chain of an acrylic polymer, when the
pellicle is peeled from the exposure original plate, peeling
residues of the agglutinant layer remaining on the exposure
original plate can be reduced. Due to the introduction of an ether
bond into an acrylic polymer, it becomes easy to control the
hydrophilicity of the acrylic polymer. In addition, the
introduction of an ether bond into the side chain of an acrylic
polymer is assumed to prevent light-deterioration of the main
chain.
[0079] A fourth aspect of the agglutinant for pellicles of the
present invention is to use, as a base material, an acrylic polymer
having a side chain that has higher degradability by irradiation
with an exposure light beam than a main chain. Because the
degradability of the side chain of the acrylic polymer by
irradiation with an exposure light beam is higher than that of the
main chain, when the pellicle is peeled from the exposure original
plate, peeling residues of the agglutinant layer remaining on the
exposure original plate can be reduced. It is assumed that since
the degradability of the side chain by the exposure light beam is
higher than that of the main chain, the degradation of the side
chain substantially precedes the degradation of the main chain, and
peeling residues can be reduced. The degradation of the side chain
has less effect on the deterioration of the agglutinant, and even
if the degradation proceeds, it is considered that the agglutinant
is less likely to remain as peeling residues during peeling due to
the cohesive force of the agglutinant. On the other hand, if the
light-deterioration of the main chain proceeds, the molecular
weight of the main chain is reduced, and it is considered that the
reduced-molecular-weight agglutinant remains on the substrate as
residues. Here, the difference in degradability can be determined,
for example, by comparing the decomposition product of the main
chain and the decomposition product of the side chain before and
after irradiation of the agglutinant with an exposure light beam by
IR, NMR, or the like. More specifically, it can be confirmed by
comparing the IR chart of the agglutinant before irradiation with
an exposure light beam with the IR chart of the agglutinant after
irradiation with an exposure light beam, and observing the change
in spectral intensity. Examples of the wave number to be confirmed
include C--O--C (methoxy group) at 1125 cm.sup.-1, C--O--C (ether
group) at 1160 cm.sup.-1, C.dbd.O (ester group) at 1727 cm.sup.-1,
and the like.
[0080] A fifth aspect of the agglutinant for pellicles of the
present invention is to use, as a base material, an acrylic polymer
having a side chain that is selectively deteriorated by irradiation
with an exposure light beam. Because the side chain of the acrylic
polymer is selectively deteriorated by irradiation with an exposure
light beam, when the pellicle is peeled from the exposure original
plate, peeling residues of the agglutinant layer remaining on the
exposure original plate can be reduced. It is assumed that since
the side chain is selectively deteriorated by irradiation with an
exposure light beam, the degradation of the side chain
substantially precedes the degradation of the main chain, and
peeling residues can be reduced. The degradation of the side chain
has relatively less effect on the deterioration of the agglutinant,
and even if the degradation proceeds, it is considered that the
agglutinant is less likely to remain as peeling residues during
peeling due to the cohesive force of the agglutinant. On the other
hand, if the light-deterioration of the main chain proceeds, the
molecular weight of the main chain is reduced, and it is considered
that the reduced-molecular-weight agglutinant remains on the
substrate as residues. Here, the presence of deterioration can be
determined, for example, by comparing the decomposition product of
the main chain and the decomposition product of the side chain
before and after irradiation of the agglutinant with an exposure
light beam by IR, NMR, or the like. More specifically, it can be
confirmed by comparing the IR chart of the agglutinant before
irradiation with an exposure light beam with the IR chart of the
agglutinant after irradiation with an exposure light beam, and
observing the change in spectral intensity. Examples of the wave
number to be confirmed include C--O--C (methoxy group) at 1125
cm.sup.-1, C--O--C (ether group) at 1160 cm.sup.-1, C.dbd.O (ester
group) at 1727 cm.sup.-1, and the like.
[0081] In the present invention, the "agglutinant comprising an
acrylic polymer as a base material" refers to an agglutinant
containing an acrylic polymer itself or an agglutinant containing a
reaction product of the acrylic polymer, a curing agent, and the
like.
[0082] The present inventors found that in a pellicle provided with
an agglutinant layer obtained from such an agglutinant, the
agglutinant layer suppressed deterioration due to an exposure light
beam, and that even if deterioration occurred, peeling residues
were less likely to be generated during peeling from the mask
substrate (exposure original plate).
[0083] In the present invention, the acrylic polymer mentioned
above is, for example, a polymer comprising a (meth)acrylic acid
ester as a monomer component, and a monomer component
copolymerizable with the (meth)acrylic acid ester can be
copolymerized, if necessary. Examples of the (meth)acrylic acid
ester include (meth)acrylic acid esters having an ether bond,
(meth)acrylic acid alkyl esters, unsaturated monomers having a
carboxyl group or a hydroxyl group, and the like. When a
(meth)acrylic acid ester having an ether bond is contained as a
monomer component, the ether bond can be introduced into the side
chain of the acrylic polymer.
[0084] Examples of the (meth)acrylic acid ester having an ether
bond ((A) component) include (meth)acrylic acid esters having an
alkylene oxide group, such as an ethylene oxide group, a propylene
oxide group, or a butylene oxide group. Among these, (meth)acrylic
acid esters having an ethylene oxide group (also referred to as
ethylene oxide group-containing (meth)acrylates) are preferable.
Examples thereof include methoxypolyethylene glycol
(meth)acrylates, such as 2-methoxyethyl (meth)acrylate,
2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate,
phenoxyethylene glycol (meth)acrylate, and methoxydiethylene glycol
(meth)acrylate; ethoxypolyethylene glycol (meth)acrylates, such as
ethoxydiethylene glycol (meth)acrylate; butoxypolyethylene glycol
(meth)acrylates, such as butoxydiethylene glycol (meth)acrylate;
phenoxypolyethylene glycol (meth)acrylates, such as
phenoxydiethylene glycol (meth)acrylate; and the like. These may be
used singly or in combination of two or more.
[0085] Examples of the (meth)acrylic acid alkyl ester ((B)
component) include (meth)acrylic acid alkyl esters having a
C.sub.1-14 alkyl group, and the like. Specific examples thereof
include methyl (meth)acrylate, ethyl (meth)acrylate, propyl
(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,
isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate,
isononyl (meth)acrylate, lauryl (meth)acrylate, and the like. Among
these, (meth)acrylic acid alkyl esters having a C.sub.4 or C.sub.8
alkyl group are preferable, in terms of satisfying both agglutinant
characteristics and peeling characteristics. These may be used
singly or in combination of two or more.
[0086] Examples of the unsaturated monomer having a carboxyl group
or a hydroxyl group ((C) component) include
.alpha.,.beta.-unsaturated carboxylic acids, such as (meth)acrylic
acid, maleic acid, crotonic acid, itaconic acid, and fumaric acid;
hydroxyl group-containing methacrylates, such as 2-hydroxyethyl
(meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl
(meth)acrylate; and the like. These may be used singly or in
combination of two or more.
[0087] The ratio of the (A) component used in the acrylic polymer
is preferably 30 mass % or more, more preferably 35 mass % or more,
particularly preferably 35 to 98 mass %, and extremely preferably
40 to 95 mass %, in the whole monomer components. Because of the
ratio of the (A) component within the above range, it becomes easy
to control peeling residues and light resistance.
[0088] The ratio of the (B) component used in the acrylic polymer
is preferably 0 to 70 mass %, and more preferably 3 to 55 mass %,
in the whole monomer components. Because of the ratio of the (B)
component within the above range, it becomes easy to control
adhesion.
[0089] The ratio of the (C) component used in the acrylic polymer
is preferably 0 to 10 mass %, and more preferably 2 to 8 mass % in
the whole monomer components. Because of the ratio of the (C)
component within the above range, it becomes easy to control
peeling residues and the degree of crosslinking due to the reaction
with a curing agent.
[0090] The acrylic polymer can be produced, for example, by
selecting a known production method, such as solution
polymerization, bulk polymerization, emulsion polymerization, or
radical polymerization. Further, the obtained acrylic polymer may
be any of a random copolymer, a block copolymer, a graft copolymer,
and the like.
[0091] When the molecular weight of the acrylic polymer is within
the range of 700,000 to 2.5 million as weight average molecular
weight, the agglutinant layer has moderate cohesive force and
adhesive strength, and the agglutinant causes less adhesive
residues and has sufficient adhesive strength and load resistance,
which is preferable.
[0092] The weight average molecular weight mentioned above is a
value measured by gel permeation chromatography (GPC) analysis, and
refers to a value in terms of standard polystyrene. The GPC
analysis can be performed using tetrahydrofuran (THF) as an
eluent.
[0093] In the present embodiment, a reaction product of the acrylic
polymer and a curing agent is preferably contained as the
agglutinant of the agglutinant layer; however, in terms of
flexibility, an acrylic polymer that does not react with the curing
agent may be contained.
[0094] The curing agent is not particularly limited as long as it
is a curing agent that is used as a general agglutinant, and
examples thereof include metal salts, metal alkoxides, aldehyde
type compounds, non-amino resin type amino compounds, urea type
compounds, isocyanate type compounds, polyfunctional epoxy
compounds, metal chelate type compounds, melamine type compounds,
aziridine type compounds, and the like. Among these, isocyanate
type compounds and epoxy compounds are preferable, in terms of the
reactivity with the carboxyl group or the hydroxyl group.
[0095] Examples of isocyanate type compounds include xylylene
diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate,
and multimers, derivatives, and polymers thereof, and the like.
These may be used singly or in combination of two or more.
[0096] Examples of epoxy compounds include compounds having two or
more epoxy groups in the molecule, and specific examples thereof
include ethylene glycol diglycidyl ether, polyethylene glycol
diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl
ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane
triglycidyl ether, diglycidylaniline, diamine glycidylamine,
N,N,N',N'-tetraglycidyl-m-xylylenediamine,
1,3-bis(N,N'-diamineglycidylaminomethyl), and the like. These may
be used singly or in combination of two or more.
[0097] In the present invention, the definition of the SP value is
as described below.
[Method for Calculating SP Value]
[0098] In the present invention, the SP value is a solubility
parameter. The SP value can be determined by the following Equation
1 with reference to the Fedors calculation method ["Polymer
Engineering and Science," Vol. 14, No. 2 (1974), pp. 148-154].
.delta. = ( i .times. .DELTA. .times. e .times. i i .times. .DELTA.
.times. v .times. i ) 1 2 [ Equation .times. .times. 1 ]
##EQU00001##
[0099] In the above Equation 1, .delta. is a solubility parameter
(SP value), .DELTA.ei is molar evaporation energy, and .DELTA.vi is
molar volume. Further, the unit of the solubility parameter is
(cal/mol).sup.1/2. Table 1 shows the eigenvalues of .DELTA.ei and
.DELTA.vi given to the main atoms or atomic groups with respect to
the above Equation 1.
TABLE-US-00001 TABLE 1 Atom or atomic group ei (cal/mol) vi
(cm.sup.3/mol) C 350 -19.2 --CH.sub.2-- 1180 16.1 --CH.sub.3 1125
33.5 CH.sub.2.dbd. 1030 28.5 --CH.dbd. 1030 13.5 -phenyl 7630 71.4
--O-- 800 3.8 --CO-- 4150 10.8 --COO-- 4300 18.0 --OH 7120 10.0
--CONH.sub.2 10000 17.5 --CONH-- 8000 9.5 --NH.sub.2 3000 19.2
--NH-- 2000 4.5 --CN 6100 24.0 --COOH 6600 28.5 Si 810 0.0 F 1000
18.0 Cl 2760 24.0
[0100] The SP value (solubility parameter) of the acrylic polymer
is preferably 10.0 to 12.0, and more preferably 10.0 to 11.0.
[0101] The SP value of the acrylic polymer can be controlled, for
example, by changing the concentration of polar groups in the
acrylic polymer. For example, when a relatively higher polar bond,
such as an ether bond, is introduced into the side chain, the SP
value tends to increase. On the other hand, when a relatively less
polar bond, such as a long-chain alkylene bond, is introduced into
the side chain, the SP value tends to decrease.
[0102] In the agglutinant of the present invention, two or more
acrylic polymers, such as two or more acrylic polymers having
different weight average molecular weights, two or more acrylic
polymers containing different monomer components, or two or more
acrylic polymers with different copolymerization ratios, may be
combined as the base material. In such case, within the range in
which the effects of the present invention are exhibited, the SP
value of only a single acrylic polymer may be within the range, or
the SP values of all of the acrylic polymers may be out of the
range, but the SP value of the entire acrylic polymer component may
be within the range. Here, the SP value of the entire acrylic
polymer component is calculated by dividing the SP value of each of
two or more acrylic polymers proportionally by their respective
mixing amounts.
[0103] In order to reduce distortion and other influences on the
mask substrate to which the pellicle is bonded, and to suppress
residual stress due to pellicle bonding, the shape of the
agglutinant layer 14 is preferably a flat shape that is less likely
to deform during bonding of the pellicle.
[0104] It was also found that more preferred results tended to be
obtained when the agglutinant layer contained a polyvinyl ether
compound. Specifically, when mixing was performed so that vinyl
ether groups were uniformly dispersed in the whole agglutinant
layer, the peeling properties of the agglutinant were further
improved, and almost no residues were observed in the visual
inspection. Even when the agglutinant layer in which vinyl ether
groups were uniformly dispersed was bonded to a mask substrate and
then irradiated with 193-nm ultraviolet rays, dust was hardly
generated, and the probability of good peeling substantially
without leaving peeling residues on the mask substrate was
significantly increased.
[0105] That is, in the best mode of the present invention, the
pellicle uses, as a base material that constitutes the mask
agglutinant layer, an acrylic polymer having an SP value of 10.0 or
more and 12.0 or less, and contains a polyvinyl ether compound,
whereby even when an exposure light beam is applied through the
mask substrate, surface deterioration is reduced, and fine
particulate residues are also reduced when the pellicle is peeled
from the mask substrate. As a result, the regeneration cleaning of
the mask substrate, from which the pellicle is peeled, proceeds
smoothly, the cleaning conditions can be loosened, and there is an
advantage in reducing damage to the mask surface during
cleaning.
[0106] Examples of the polyvinyl ether compound include
homopolymers of vinyl ethers, such as methyl vinyl ether, ethyl
vinyl ether, butyl vinyl ether, isobutyl vinyl ether, and
(2-methoxyethyl) vinyl ether; copolymers of two or more vinyl
ethers; copolymers of these vinyl ethers and other monomers; and
the like. Among these, polyvinyl ether compounds containing methyl
vinyl ether as a raw material monomer component are preferable in
terms of the control of peeling residues.
[0107] In the agglutinant that forms the agglutinant layer 14, the
mixing ratio of an acrylic polymer mentioned above, and the
polyvinyl ether compound is, based on mass, 90:10 to 99:1,
preferably 92:8 to 98:2, and particularly preferably 94:6 to 96:4,
in terms of reducing peeling residues.
[0108] In addition, the agglutinant that forms the agglutinant
layer of the pellicle may be mixed with other components, such as
crosslinking agents, tackifiers, plasticizers, stabilizers,
viscosity regulators, antistatic agents, lubricants,
conductivity-imparting agents, flame retardancy-imparting agents,
thermal conductivity-improving agents, heat resistance-improving
agents, weather resistance-improving agents, thixotropy-imparting
agents, antioxidants, antimicrobial agents, antifungal agents, and
coloring agents, depending on the purpose within the range in which
the characteristics of the present invention are not impaired.
[0109] As the means for forming the agglutinant layer 14, an
uncured liquid or paste agglutinant is applied to the lower end
face of the pellicle frame 11, followed by curing treatment,
thereby forming an agglutinant layer. The agglutinant may be
applied once, or may be repeatedly applied several times in order
to obtain a predetermined thickness of the agglutinant layer. In
this case, the agglutinant is preferably allowed to stand between
each time of coating until the shape of the agglutinant after
coating is stabilized. If it is difficult to apply an agglutinant
due to its high viscosity, the agglutinant may be applied, if
necessary, after dilution with an organic solvent, alcohol, water,
or the like to reduce the viscosity of the agglutinant. The
agglutinant can be applied, for example, by dipping, spraying, or
brush coating, or by using a coating device with a dispenser or the
like. Coating using a coating device with a dispenser is
preferable, in terms of stability, workability, yield, and the
like.
[0110] In the production of the pellicle 10, the coating and
formation of the agglutinant layer 14 are generally performed
first, followed by stretching of the pellicle film 12; however, the
order may be reversed. For stretching the pellicle film 12, for
example, an adhesive material is applied to the upper end face of
the pellicle frame 11, and the pellicle frame 11 is then heated to
cure the adhesive material. Finally, the upper end face of the
pellicle frame 11, on which the adhesive material layer 13 for
bonding a pellicle film is formed, is bonded to a pellicle film
taken in an aluminum frame larger than the pellicle frame 11, and
extra portions of the pellicle film protruding outside the pellicle
frame 11 are removed, thereby completing the pellicle.
[0111] Due to the use of the pellicle of the present invention with
the configuration described above, the amount of agglutinant
residues can be reduced when the pellicle is peeled from the
exposure original plate after being used in lithography. Moreover,
the present invention provides a method for reducing peeling
residues of the agglutinant layer of the pellicle by using the
pellicle of the present invention. Therefore, the pellicle of the
present invention is useful as a pellicle bonded to a phase shift
photo mask having the delicate phase shift film mentioned above, or
a face comprising silicon oxide, such as quartz, as a main
component.
[0112] The pellicle of the present invention is also useful as a
pellicle applied to exposure original plates whose agglutinant
layer is irradiated with an exposure light beam during exposure,
such as a negative type exposure original plate, an exposure
original plate that has a non-shaded area or a semi-transparent
shaded area in a portion thereof to which an agglutinant is bonded,
and an exposure original plate that has a transparent area in a
portion thereof to which an agglutinant is bonded. The agglutinant
layer of the pellicle used in such an exposure original plate is
exposed to an exposure light beam through the exposure original
plate from the face of the exposure original plate opposite to the
face provided with the pellicle.
[0113] The pellicle of the present invention may be used not only
as a protective member for suppressing the adhesion of foreign
substances to the exposure original plate in the exposure device,
but also as a protective member for protecting the exposure
original plate during storage or transportation of the exposure
original plate. An exposure original plate with a pellicle can be
produced by mounting the pellicle described above on an exposure
original plate, such as a photo mask.
[0114] The method for producing a semiconductor device or a liquid
crystal display board according to the present embodiment comprises
a step of exposing a substrate (semiconductor wafer or liquid
crystal original plate) using the exposure original plate with a
pellicle described above. For example, in the lithography step,
which is one of the steps for producing semiconductor devices or
liquid crystal display boards, in order to form a photoresist
pattern corresponding to an integrated circuit etc. on a substrate,
the exposure original plate with a pellicle described above is set
on a stepper to perform exposure. As a result, if foreign
substances adhere to the pellicle in the lithography step, the
foreign substances do not form images on the wafer coated with a
photoresist; thus, the short circuit, disconnection, and the like
of the integrated circuit etc. due to images of the foreign
substances can be prevented. Therefore, the use of the exposure
original plate with a pellicle can improve the yield in the
lithography step.
[0115] In general, when a desired number of times of lithography
steps are performed, when foreign substances and haze are
generated, or when the pellicle film is damaged, the pellicle is
peeled from the exposure original plate, and the exposure original
plate is subjected to regeneration cleaning in some cases. Due to
the use of the pellicle of the present invention, peeling residues
during repellicle can be reduced even in the case of exposure
original plates whose agglutinant layer is irradiated with an
exposure light beam during exposure, such as an exposure original
plate having a face comprising silicon oxide as a main component in
which peeling residues of the agglutinant layer are likely to be
generated, a negative type exposure original plate whose
agglutinant layer is irradiated with an exposure light beam more
than before, an exposure original plate that has a non-shaded area
or a semi-transparent shaded area in a portion thereof to which an
agglutinant is bonded, whose agglutinant layer is irradiated with
an exposure light beam more than before, and an exposure original
plate that has a transparent area in a portion thereof to which an
agglutinant is bonded, whose agglutinant layer is irradiated with
an exposure light beam more than before.
[0116] Moreover, since the use of the pellicle of the present
invention can reduce peeling residues of the agglutinant layer,
cleaning with functional water can be easily applied, and cleaning
properties for delicate exposure original plates, such as phase
shift photo masks, can be improved. In addition, the use of the
pellicle of the present invention can contribute to the reduction
of environmental burden caused by cleaning with functional
water.
EXAMPLES
[0117] The present invention will be described in more detail below
with reference to Examples. The "mask" in the Examples and
Comparative Examples is described as an example of the "exposure
original plate." Needless to say, it can also be applied to
reticles.
Example 1
[0118] After a pellicle frame (external size: 149 mm.times.115
mm.times.3.5 mm, thickness: 2 mm, flatness of an end face coated
with a mask bonding agglutinant: 15 um) made of an aluminum alloy
was subjected to precision cleaning, an acrylic agglutinant
manufactured by Soken Chemical Co., Ltd. (product name: SK-Dyne
SN-70A, containing, as a base material, an acrylic polymer in which
95 mass % of monomer components was an ethylene oxide
group-containing (meth)acrylate; SP value of the base material:
10.2) was applied to the end face with a flatness of 15 um, and
allowed to stand for 60 minutes at room temperature. Thereafter, a
separator was placed on an aluminum plate with a flatness of 5 um,
and the pellicle frame coated with the agglutinant was placed so
that the agglutinant faced down. Thus, the agglutinant was brought
into contact with the flat separator and flattened.
[0119] Next, the pellicle on the aluminum plate was placed in an
oven at 60.degree. C. for 60 minutes to cure the agglutinant.
[0120] After the pellicle together with the aluminum plate was
taken out from the oven, the separator was peeled.
[0121] Thereafter, an adhesive material manufactured by AGC Inc.
(trade name: Cytop CTX-A) was applied to the end face opposite to
the end face coated with the agglutinant. Then, the pellicle frame
was heated at 130.degree. C. to cure the adhesive material.
[0122] Finally, the adhesive material-coated end face of the
pellicle frame was bonded to a pellicle film taken in an aluminum
flame larger than the pellicle frame, and portions outside the
pellicle frame were removed, thereby completing the pellicle.
[0123] Next, a 6025 mask substrate (6 inch) and the previously
prepared pellicle were set in a bonding device, and pressurized at
a bonding load of 50 N for a load time of 30 seconds to bond the
pellicle to the mask substrate.
[0124] After the mask substrate to which the pellicle was bonded
was left for 24 hours at room temperature, the back surface of the
mask was irradiated with ultraviolet rays at 10 mJ/cm.sup.2 using a
193-nm ultraviolet lamp so that the light beam was applied to the
pellicle agglutinant.
[0125] After ultraviolet irradiation, the resultant was left for 1
hour at room temperature, and then the pellicle was slowly peeled
upward from the mask substrate at a speed of 0.1 mm/sec.
[0126] When the mask substrate after peeling was visually observed,
a pale opaque band, which was considered to be agglutinant solute
residues, was slightly found in the contour portion to which the
pellicle was bonded, and the surface of the mask substrate was
obviously cleaner than the Comparative Examples, described later.
The residues could be removed by cleaning for 5 minutes in a
cleaning tank using functional water (hydrogen and ammonia were
added to ultrapure water) in combination with ultrasonic waves
(functional water overflowed).
Example 2
[0127] A pellicle was completed in the same manner using the same
materials as in Example 1, except that the agglutinant used herein
was an acrylic agglutinant manufactured by Soken Chemical Co., Ltd.
(product name: SN-25B, containing, as a base material, an acrylic
polymer in which 40 mass % of monomer components was an ethylene
oxide group-containing (meth)acrylate; SP value of the base
material: 10.5). Further, the pellicle was bonded to and peeled
from a mask substrate under the same conditions as in Example
1.
[0128] When the mask substrate after peeling was visually observed,
a pale opaque band, which was considered to be agglutinant solute
residues, was slightly found in the contour portion to which the
pellicle was bonded, and the surface of the mask substrate was
obviously cleaner than the Comparative Examples, described later.
The residues could be removed by cleaning for 5 minutes twice in a
cleaning tank using functional water (hydrogen and ammonia were
added to ultrapure water) in combination with ultrasonic waves
(functional water overflowed), as in Example 1.
Example 3
[0129] A pellicle was completed in the same manner using the same
materials as in Example 1, except that the agglutinant used herein
contained 3 mass parts of a polyvinyl ether compound based on 100
mass parts of SK-Dyne SN-70A. Further, the pellicle was bonded to
and peeled from a mask substrate under the same conditions as in
Example 1.
[0130] When the mask substrate after peeling was visually observed,
a pale shiny transparent band, which was considered to be
agglutinant solute residues, was slightly found in the contour
portion to which the pellicle was bonded, and the mask substrate
was so clean that almost no agglutinant solute residue was
confirmed. As for the subsequent cleaning, the residues could be
removed by cleaning for 3 minutes using the same equipment as in
Example 1.
Comparative Example 1
[0131] A pellicle was completed in the same manner using the same
materials as in Example 1, except that the agglutinant used herein
was an acrylic agglutinant manufactured by Soken Chemical Co., Ltd.
(product name: SK-Dyne SK-1425S, containing, as a base material, an
acrylic polymer not containing a (meth)acrylic acid ester having an
ether bond as a monomer component; SP value of the base material:
9.8). Further, the pellicle was bonded to and peeled from a mask
substrate under the same conditions as in Example 1.
[0132] When the mask substrate after peeling was visually observed,
pale agglutinant solute residues were found in the portion to which
the pellicle was bonded. The peeling residues could not be
completely removed by cleaning for 5 minutes twice using the same
equipment as in Example 1. Accordingly, light rubbing using a
foamed polyvinyl alcohol was necessary before cleaning.
Comparative Example 2
[0133] A pellicle was completed in the same manner using the same
materials as in Example 1, except that the agglutinant used herein
was an acrylic agglutinant manufactured by Soken Chemical Co., Ltd.
(product name: SK-Dyne SK-1495S, containing, as a base material, an
acrylic polymer not containing a (meth)acrylic acid ester having an
ether bond as a monomer component; SP value of the base material:
9.2). Further, the pellicle was bonded to and peeled from a mask
substrate under the same conditions as in Example 1.
[0134] When the mask substrate after peeling was visually observed,
pale agglutinant solute residues were found in the portion to which
the pellicle was bonded. The peeling residues could not be removed
only by ultrasonic cleaning with functional water, as in
Comparative Example 1, but could be removed by the combined use of
rubbing cleaning with a foamed polyvinyl alcohol before ultrasonic
cleaning.
Synthesis Example 1
[0135] A 5-L flask equipped with a stirrer, a reflux condenser, a
thermometer, and a gas inlet was charged with 320 g of butyl
acrylate, 550 g of 2-methoxyethyl acrylate, 80 g of acrylic acid,
50 g of 2-hydroxyethyl acrylate, 1500 g of ethyl acetate, and 2 g
of azobisisobutyronitrile as a polymerization initiator. Solution
polymerization was carried out at 68.degree. C. for 8 hours in a
nitrogen gas stream. After the completion of the reaction, 830 g of
ethyl acetate was added thereto, thereby obtaining a solution of an
acrylic polymer with a solid content of 30% (SP value: 10.6). A
polyisocyanate solution was added to the obtained acrylic polymer
solution, and the mixture was stirred and mixed to obtain an
agglutinant.
Synthesis Example 2
[0136] A 5-L flask equipped with a stirrer, a reflux condenser, a
thermometer, and a gas inlet was charged with 400 g of 2-ethylhexyl
acrylate, 500 g of 2-ethoxyethyl acrylate, 100 g of acrylic acid,
1200 g of ethyl acetate, and 2 g of azobisisobutyronitrile as a
polymerization initiator. Solution polymerization was carried out
at 68.degree. C. for 8 hours in a nitrogen gas stream. After the
completion of the reaction, 1130 g of ethyl acetate was added
thereto, thereby obtaining a solution of an acrylic polymer with a
solid content of 30% (SP value: 10.1). A polyisocyanate solution
was added to the obtained acrylic polymer solution, and the mixture
was stirred and mixed to obtain an agglutinant.
Synthesis Example 3
[0137] A 5-L flask equipped with a stirrer, a reflux condenser, a
thermometer, and a gas inlet was charged with 350 g of 2-ethylhexyl
acrylate, 550 g of 2-methoxyethyl acrylate, 50 g of methacrylic
acid, 50 g of 2-hydroxyethyl methacrylate, 1400 g of ethyl acetate,
and 2 g of azobisisobutyronitrile as a polymerization initiator.
Solution polymerization was carried out at 68.degree. C. for 8
hours in a nitrogen gas stream. After the completion of the
reaction, 930 g of ethyl acetate was added thereto, thereby
obtaining a solution of an acrylic polymer with a solid content of
30% (SP value: 10.2). A polyisocyanate solution was added to the
obtained acrylic polymer solution, and the mixture was stirred and
mixed to obtain an agglutinant.
Synthesis Example 4
[0138] A 5-L flask equipped with a stirrer, a reflux condenser, a
thermometer, and a gas inlet was charged with 300 g of butyl
acrylate, 550 g of 2-methoxyethyl acrylate, 100 g of 2-hydroxybutyl
acrylate, 50 g of itaconic acid, 1500 g of ethyl acetate, and 2 g
of azobisisobutyronitrile as a polymerization initiator. Solution
polymerization was carried out at 68.degree. C. for 8 hours in a
nitrogen gas stream. After the completion of the reaction, 830 g of
ethyl acetate was added thereto, thereby obtaining a solution of an
acrylic polymer with a solid content of 30% (SP value: about 10.7).
A polyisocyanate solution was added to the obtained acrylic polymer
solution, and the mixture was stirred and mixed to obtain an
agglutinant.
Synthesis Example 5
[0139] A 5-L flask equipped with a stirrer, a reflux condenser, a
thermometer, and a gas inlet was charged with 300 g of butyl
acrylate, 600 g of methoxypolyethylene glycol acrylate, 100 g of
acrylic acid, 1400 g of ethyl acetate, and 2 g of
azobisisobutyronitrile as a polymerization initiator. Solution
polymerization was carried out at 68.degree. C. for 8 hours in a
nitrogen gas stream. After the completion of the reaction, 930 g of
ethyl acetate was added thereto, thereby obtaining a solution of an
acrylic polymer with a solid content of 30% (SP value: about 10). A
polyisocyanate solution was added to the obtained acrylic polymer
solution, and the mixture was stirred and mixed to obtain an
agglutinant.
Examples 4 to 8
[0140] Pellicles were produced in the same manner as in Example 1,
except that the agglutinant used herein was each of the
agglutinants obtained in Synthesis Examples 1 to 5, and a peeling
test was performed. As a result, the pellicles using any of the
agglutinants resulted in reduced peeling residues and had improved
cleaning removing properties, compared with the Comparative
Examples.
EXPLANATION FOR REFERENCE NUMERALS
[0141] 1: exposure original plate [0142] 10: pellicle [0143] 11:
pellicle frame [0144] 12: pellicle film [0145] 13: adhesive
material layer for bonding pellicle film [0146] 14: agglutinant
layer [0147] 15: air pressure adjustment hole (vent) [0148] 16:
dust removal filter
* * * * *