U.S. patent application number 17/220759 was filed with the patent office on 2021-07-22 for photocurable composition for imprint, method for producing film using the same, method for producing optical component using the same, method for producing circuit board using the same, and method for producing electronic component using the same.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Takeshi Honma, Toshiki Ito, Kazumi Iwashita, Tomonori Otani, Shiori Yonezawa.
Application Number | 20210223690 17/220759 |
Document ID | / |
Family ID | 1000005493237 |
Filed Date | 2021-07-22 |
United States Patent
Application |
20210223690 |
Kind Code |
A1 |
Yonezawa; Shiori ; et
al. |
July 22, 2021 |
PHOTOCURABLE COMPOSITION FOR IMPRINT, METHOD FOR PRODUCING FILM
USING THE SAME, METHOD FOR PRODUCING OPTICAL COMPONENT USING THE
SAME, METHOD FOR PRODUCING CIRCUIT BOARD USING THE SAME, AND METHOD
FOR PRODUCING ELECTRONIC COMPONENT USING THE SAME
Abstract
A photocurable composition for imprint at least has a
polymerizable compound (A) and a photopolymerization initiator (B),
in which the polymerizable compound (A) contains 20% by weight or
more of a multifunctional (meth)acrylic monomer and the glass
transition temperature of a photocured substance of the
photocurable composition is 90.degree. C. or more.
Inventors: |
Yonezawa; Shiori; (Tokyo,
JP) ; Ito; Toshiki; (Kawasaki-shi, JP) ;
Otani; Tomonori; (Iruma-shi, JP) ; Iwashita;
Kazumi; (Kobe-shi, JP) ; Honma; Takeshi;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
1000005493237 |
Appl. No.: |
17/220759 |
Filed: |
April 1, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15537320 |
Jun 16, 2017 |
11003073 |
|
|
PCT/JP2015/006244 |
Dec 15, 2015 |
|
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17220759 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/0337 20130101;
G03F 7/0002 20130101; H01L 21/0271 20130101; G02B 5/1857 20130101;
C08F 2/50 20130101 |
International
Class: |
G03F 7/00 20060101
G03F007/00; G02B 5/18 20060101 G02B005/18; C08F 2/50 20060101
C08F002/50; H01L 21/033 20060101 H01L021/033 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2014 |
JP |
2014-257798 |
May 14, 2015 |
JP |
2015-099486 |
Nov 28, 2015 |
JP |
2015-232535 |
Claims
1. A photocurable composition for a cured film which is obtained by
curing the photocurable composition applied on a substrate and used
when etching the substrate, the photocurable composition at least
comprising: a polymerizable compound (A); and a photopolymerization
initiator (B), wherein the polymerizable compound (A) contains 25%
by weight or more of a multifunctional (meth)acrylic monomer,
wherein a glass transition temperature of a photocured substance of
the photocurable composition is 101.degree. C. or more, wherein the
polymerizable compound (A) is a mixture of a monofunctional
(meth)acrylic monomer and a multifunctional (meth)acrylic monomer,
wherein an Ohnishi parameter of the polymerizable compound (A) is
3.2 or less.
2. The photocurable composition according to claim 1, wherein the
polymerizable compound (A) contains 40% by weight or more of the
multifunctional (meth)acrylic monomer.
3. The photocurable composition according to claim 1, wherein a
glass transition temperature of a photocured substance of the
photocurable composition is 131.degree. C. or more.
4. The photocurable composition according to claim 1, wherein a
viscosity of the photocurable composition is 5 mPa*s or more and 50
mPa*s or less.
5. The photocurable composition according to claim 1, wherein a
viscosity of the photocurable composition is 3 mPa*s or more and
10.6 mPa*s or less.
6. The photocurable composition according to claim 1, wherein the
photocurable composition having a glass transition temperature of
101.degree. C. or more is specified by measuring a loss tangent tan
.delta. of a film obtained by photocuring a photocurable
composition containing 100 parts by weight of the polymerizable
compound (A) and 3 parts by weight of Lucirin TPO as the
photopolymerization initiator (B) while increasing a temperature to
find out that a temperature at which the tan .delta. reaches a
maximum is 101.degree. C. or more.
7. The photocurable composition according to claim 1, wherein a
multifunctional acrylic monomer contained in the polymerizable
compound (A) is any one of m-xylylene diacrylate, phenyl ethylene
glycol diacrylate, and 2-phenyl-1,3-propanediol diacrylate.
8. A method for producing a film comprising: a step (1) of
arranging the photocurable composition according to claim 1 on a
substrate; a step (2) of bringing the curable composition into
contact with a mold; a step (3) of aligning the substrate and the
mold; a step (4) of irradiating the curable composition with light
to form a photocured film; and a step (5) of releasing the cured
film and the mold from each other.
9. The method for producing a film according to claim 8, comprising
performing the steps (1) to (5) two or more times to different
regions on the substrate.
10. The method for producing a film according to claim 8, wherein a
surface of the mold contains quartz.
11. The method for producing a film according to claim 8, wherein
the step (2) is performed under an atmosphere containing
condensable gas.
12. A method for producing an optical component, comprising the
step of obtaining a film by the manufacturing method according to
claim 8.
13. A method for producing an optical component, comprising: a step
of obtaining a film by the manufacturing method according to claim
8; and a step of performing etching or ion implantation to a
substrate.
14. A method for producing a circuit board, comprising: a step of
obtaining a film by the manufacturing method according to claim 8;
and a step of performing etching or ion implantation to a substrate
using the obtained film.
15. A method for producing an electronic component, comprising: a
step of obtaining a circuit board by the method for producing a
circuit board according to claim 14.
16. The method for producing an electronic component according to
claim 15, wherein the electronic component is a semiconductor
device.
17. A photocured film for dry etching, which is used for dry
etching, the photocured film being obtained by curing the
photocurable composition according to claim 1 on the substrate.
18. A semiconductor substrate pretreated by dry etching,
comprising: a semiconductor substrate; and the photocured film for
etching according to claim 17 patterned onto the semiconductor
substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/537,320, filed Jun. 16, 2017, which is a National Stage
filing of International Application No. PCT/JP2015/006244 filed
Dec. 15, 2015, which claims the benefit of Japanese Patent
Application Nos. 2014-257798, filed Dec. 19, 2014, 2015-099486,
filed May 14, 2015, and 2015-232535, filed Nov. 28, 2015 which are
hereby incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a photocurable composition
for imprint, a method for producing a film using the same, a method
for producing an optical component using the same, a method for
producing a circuit board using the same, and a method for
producing an electronic component using the same.
BACKGROUND ART
[0003] A demand for miniaturization in semiconductor devices, MEMS,
and the like has increased. Therefore, a micromachining technique
utilizing a pattern of a resist (photocurable composition for
nanoimprint) which is formed on a substrate (wafer) and has a
predetermined shape as a mold has recently drawn attention in
addition to a former photolithographic technique. This technique is
also referred to as an optical imprint (optical nanoimprint) and
can form a fine structure of the order of several nanometers on a
substrate (PTL 1). According to the optical imprint technique, a
resist is first applied to a pattern formation region on a
substrate (Arrangement step). Next, this resist is molded using a
mold on which a pattern is formed (Mold contact step). Then, light
is emitted to cure the resist (Light irradiation step), and then
the cured resist is released (Mold release step). By carrying out
these steps, the pattern of the resist cured substance (photocured
film) having a predetermined shape is formed on the substrate.
Furthermore, by repeating all the steps described above at other
positions on the substrate, a fine structure can be formed on the
entire substrate.
[0004] The photocured film having the pattern formed on the
substrate by the optical imprint technique is sometimes utilized as
a mask in processing a base substrate using a dry etching
technique. In this case, in order to process the base substrate
with a good yield, the photocured film is required to have high dry
etching resistance. Moreover, in manufacturing a semiconductor
device, it is required to form a circuit pattern with an accuracy
of about .+-.10 to 12% of a desired line width.
CITATION LIST
Patent Literature
[0005] PTL 1: Japanese Patent Laid-Open No. 2007-186570
SUMMARY OF INVENTION
Technical Problem
[0006] When transferring the pattern of the resist cured substance
to a circuit pattern using the dry etching technique, the resist
cured substance thermally expands due to the reaction heat
generated in etching. Therefore, when the coefficient of thermal
expansion of the resist cured substance is large, expansion and
distortion of the pattern line width are caused, which has posed a
problem that a circuit pattern with a demanded accuracy is not
obtained.
[0007] Moreover, when industrially utilizing the optical imprint
method, it has been required in order to obtain high productivity
that, after bringing a photocurable composition for imprint into
contact with a mold, the photocurable composition for imprint is
promptly filled into concave portions of a fine pattern on the
mold.
[0008] In order to solve the above-described problems, a
photocurable composition for imprint having small thermal expansion
in curing and having excellent filling properties is required.
[0009] The present invention provides a photocurable composition
for imprint having small thermal expansion in dry etching and
having excellent filling properties in an optical imprint method.
The present invention also provides a film production method using
a photocurable composition for imprint, a method for producing an
optical component using the same, a method for producing a circuit
board using the same, and a method for producing an electronic
component using the same.
Solution to Problem
[0010] The present invention is a photocurable composition for
imprint at least having a polymerizable compound (A) and a
photopolymerization initiator (B), in which the polymerizable
compound (A) contains 20% by weight or more of a multifunctional
(meth)acrylic monomer and the glass transition temperature of a
photocured substance of the photocurable composition is 90.degree.
C. or more.
[0011] Further features of the present invention will become
apparent from the following description of exemplary embodiments
with reference to the attached drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1A is a schematic cross sectional view illustrating an
example of a method for producing a film of this embodiment.
[0013] FIG. 1B includes FIGS. 1B(b-1) and 1B(b-2) illustrating
schematic cross sectional views illustrating the example of a
method for producing a film of this embodiment.
[0014] FIG. 1C is a schematic cross sectional view illustrating the
example of a method for producing a film of this embodiment.
[0015] FIG. 1D includes FIGS. 1D(d-1) and 1D(d-2) illustrating
schematic cross sectional views illustrating the example of a
method for producing a film of this embodiment.
[0016] FIG. 1E is a schematic cross sectional view illustrating the
example of a method for producing a film of this embodiment.
[0017] FIG. 1F is a schematic cross sectional view illustrating the
example of a method for producing a film of this embodiment.
[0018] FIG. 1G is a schematic cross sectional view illustrating the
example of a method for producing a film of this embodiment.
DESCRIPTION OF EMBODIMENTS
[0019] Hereinafter, an embodiment of the present invention is
described in detail with reference to the drawings as appropriate.
However, the present invention is not limited to the embodiments
described below. In the present invention, those obtained by, for
example, altering and modifying as appropriate the embodiments
described below without deviating from the scope based on usual
knowledges of the persons skilled in the art is included in the
scope of the present invention.
Photocurable Composition for Imprint
[0020] In this embodiment, a photocurable composition for imprint
is a curable composition at least containing a component (A) and a
component (B) described below:
Component (A): polymerizable compound; and Component (B):
Photopolymerization initiator.
[0021] In particular, the photocurable composition for imprint is
suitable for the use of forming a nano-order (1 nm to several
hundreds nm) pattern of a photocured film on a base material, such
as a semiconductor substrate, which is referred to as nanoimprint.
Furthermore, the photocurable composition for imprint is also
suitable for the use of dry etching a photocured film formed by the
nanoimprint to process the base material.
[0022] In this embodiment, the photocured film means a film
obtained by polymerizing the photocurable composition on a
substrate, and then curing the same. Furthermore, the photocured
film may have a pattern shape.
[0023] Hereinafter, each component is described in detail.
Component (A): Polymerizable Compound
[0024] The component (A) is a polymerizable compound. Herein, in
this embodiment, the polymerizable compound is a compound which
reacts with a polymerization factor (radical and the like)
generated from the photopolymerization initiator (component (B)) to
form a film containing a high molecular weight compound by a chain
reaction (polymerization reaction).
[0025] As such a polymerizable compound, a radical polymerizable
compound is mentioned, for example. The polymerizable compound
which is the component (A) may contain one kind of a polymerizable
compound or may contain two or more kinds of polymerizable
compounds.
[0026] The radical polymerizable compound is suitably a compound
having one or more acryloyl groups or methacryloyl groups, i.e., a
(meth)acrylic compound.
[0027] Therefore, the component (A) (polymerizable compound) of the
photocurable composition for nanoimprint suitably contains a
(meth)acrylic compound. The main component of the component (A) is
more suitably a (meth)acrylic compound. It is the most suitable for
the component (A) to contain only a (meth)acrylic compound. Herein,
the fact that the main component of the component (A) is a
(meth)acrylic compound means that the component (A) contains 90% by
weight or more of a (meth)acrylic compound.
[0028] When the radical polymerizable compound contains two or more
kinds of compounds having one or more acryloyl groups or
methacryloyl groups, the radical polymerizable compound suitably
contains a monofunctional (meth)acrylic monomer and a
multifunctional (meth)acrylic monomer. This is because, by
combining a monofunctional (meth)acrylic monomer and a
multifunctional (meth)acrylic monomer, a photocured film having
strong mechanical strength is obtained. In this embodiment, the
multifunctional (meth)acrylic monomer is suitably contained in a
proportion of 25% by weight or more. Thus, it is considered that
the crosslink density of the photocured film increases and the
thermal expansion in dry etching can be made small.
[0029] Examples of monofunctional(meth)acrylic compounds having one
acryloyl group or methacryloyl group include, for example,
phenoxyethyl(meth)acrylate, phenoxy-2-methylethyl(meth)acrylate,
phenoxyethoxyethyl(meth)acrylate,
3-phenoxy-2-hydroxypropyl(meth)acrylate,
2-phenylphenoxyethyl(meth)acrylate,
4-phenylphenoxyethyl(meth)acrylate,
3-(2-phenylphenyl)-2-hydroxypropyl(meth)acrylate, (meth)acrylate of
EO-modified p-cumylphenol, 2-bromophenoxyethyl(meth)acrylate,
2,4-dibromophenoxyethyl(meth)acrylate,
2,4,6-tribromophenoxyethyl(meth)acrylate, EO-modified
phenoxy(meth)acrylate, PO-modified phenoxy(meth)acrylate,
polyoxyethylene nonylphenyl ether(meth)acrylate,
isobornyl(meth)acrylate, 1-adamantyl(meth)acrylate,
2-methyl-2-adamantyl(meth)acrylate,
2-ethyl-2-adamantyl(meth)acrylate, bornyl(meth)acrylate,
tricyclodecanyl(meth)acrylate, dicyclopentanyl(meth)acrylate,
dicyclopentenyl(meth)acrylate, cyclohexyl(meth)acrylate,
4-butylcyclohexyl(meth)acrylate, acryloyl morpholine,
2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate,
2-hydroxybutyl(meth)acrylate, methyl(meth)acrylate,
ethyl(meth)acrylate, propyl(meth)acrylate, isopropyl(meth)acrylate,
butyl(meth)acrylate, amyl(meth)acrylate, isobutyl(meth)acrylate,
t-butyl(meth)acrylate, pentyl(meth)acrylate, isoamyl(meth)acrylate,
hexyl(meth)acrylate, heptyl(meth)acrylate, octyl(meth)acrylate,
isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate,
nonyl(meth)acrylate, decyl(meth)acrylate, isodecyl(meth)acrylate,
undecyl(meth)acrylate, dodecyl(meth)acrylate, lauryl(meth)acrylate,
stearyl(meth)acrylate, isostearyl(meth)acrylate,
benzyl(meth)acrylate, 1-naphthylmethyl(meth)acrylate,
2-naphthylmethyl(meth)acrylate, tetrahydrofurfuryl(meth)acrylate,
butoxyethyl(meth)acrylate, ethoxy diethylene glycol(meth)acrylate,
polyethylene glycol mono(meth)acrylate, polypropylene glycol
mono(meth)acrylate, methoxyethylene glycol(meth)acrylate,
ethoxyethyl(meth)acrylate, methoxy polyethylene
glycol(meth)acrylate, methoxy polypropylene glycol(meth)acrylate,
diacetone(meth)acryl amide, isobutoxy methyl(meth)acryl amide,
N,N-dimethyl(meth)acryl amide, t-octyl(meth)acryl amide,
dimethylaminoethyl(meth)acrylate, diethylaminoethyl(meth)acrylate,
7-amino-3,7-dimethyl octyl(meth)acrylate, N,N-diethyl(meth)acryl
amide, N,N-dimethylaminopropyl(meth)acrylamide, and the like but
the monofunctional(meth)acrylic compounds having one acryloyl group
or methacryloyl group are not limited thereto.
[0030] Examples of commercially-available items of the
monofunctional(meth)acrylic compound include Aronix M101, M102,
M110, M111, M113, M117, M5700, TO-1317, M120, M150, and M156 (all
manufactured by Toagosei Co., Ltd.), MEDOL10, MIBDOLi0, CHDOLi0,
MMDOL30, MEDOL30, MIBDOL30, CHDOL30, LA, IBXA, 2-MTA, HPA, Viscoat
#150, #155, #158, #190, #192, #193, #220, #2000, #2100, and #2150
(all manufactured by Osaka Organic Chemical Industry Co., Ltd.),
Light acrylate BO-A, EC-A, DMP-A, THF-A, HOP-A, HOA-MPE, HOA-MPL,
PO-A, P-200A, NP-4EA, NP-8EA, and Epoxyester M-600A (all
manufactured by Kyoeisha Chemical Co., Ltd.), KAYARAD TC110S,
R-564, and R-128H (all manufactured by Nippon Kayaku Co., Ltd.), NK
ester AMP-10G and AMP-20G (all manufactured by Shin-Nakamura
Chemical), FA-511A, 512A, and 513A (all manufactured by Hitachi
Chemical Co., Ltd.), PHE, CEA, PHE-2, PHE-4, BR-31, BR-31M, and
BR-32 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), VP
(manufactured by BASF), ACMO, DMAA, and DMAPAA (all manufactured by
KOHJIN Film & Chemicals Co., Ltd.), and the like but the
commercially-available items of the monofunctional(meth)acrylic
compound are not limited thereto.
[0031] Examples of multifunctional (meth)acrylic compounds having
two or more acryloyl groups or methacryloyl groups include, for
example, trimethylol propane di(meth)acrylate, trimethylol propane
tri(meth)acrylate, EO-modified trimethylol propane
tri(meth)acrylate, PO-modified trimethylol propane
tri(meth)acrylate, EO,PO-modified trimethylol propane
tri(meth)acrylate, dimethylol tricyclodecane di(meth)acrylate,
pentaerythritol tri(meth)acrylate, pentaerythritol
tetra(meth)acrylate, ethylene glycol di(meth)acrylate,
tetraethylene glycol di(meth)acrylate, phenyl ethylene glycol
di(meth)acrylate, 2-phenyl-1,3-propanediol diacrylate, polyethylene
glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate,
1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate,
neopentyl glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate,
1,10-decanediol di(meth)acrylate, 1,3-adamantane dimethanol
di(meth)acrylate, o-xylylene di(meth)acrylate, m-xylylene
di(meth)acrylate, p-xylylene di(meth)acrylate,
tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate,
tris(acryloyloxy)isocyanurate, bis(hydroxymethyl)tricyclodecane
di(meth)acrylate, dipentaerythritol penta(meth)acrylate,
dipentaerythritol hexa(meth)acrylate, EO-modified
2,2-bis(4-((meth)acryloxy) phenyl)propane, PO-modified
2,2-bis(4-((meth)acryloxy)phenyl)propane, EO,PO-modified
2,2-bis(4-((meth)acryloxy)phenyl)propane, and the like are
mentioned but the multifunctional (meth)acrylic compounds having
two or more acryloyl groups or methacryloyl groups are not limited
thereto.
[0032] Examples of commercially-available items of the
multifunctional (meth)acrylic compound include Yupimer UV SA1002
and SA2007 (all manufactured by Mitsubishi Chemical Corporation),
Viscoat #195, #230, #215, #260, #335HP, #295, #300, #360, #700,
GPT, and 3PA (all manufactured by Osaka Organic Chemical Industry
Co., Ltd.), Light acrylate 4EG-A, 9EG-A, NP-A, DCP-A, BP-4EA,
BP-4PA, TMP-A, PE-3A, PE-4A, and DPE-6A (all manufactured by a
Kyoeisha Chemical Co., Ltd.), KAYARAD PET-30, TMPTA, R-604, DPHA,
DPCA-20, -30, -60, -120, HX-620, D-310, andD-330 (all manufactured
by NipponKayaku Co., Ltd.), Aronix M208, M210, M215, M220, M240,
M305, M309, M310, M315, M325, and M400 (all manufactured by
Toagosei Co., Ltd.), Ripoxy VR-77, VR-60, and VR-90 (all
manufactured byShowa Denko), and the like are mentioned but the
commercially-available items are not limited thereto.
[0033] In the compound groups mentioned above, the (meth)acrylate
refers to acrylate or methacrylate having an alcohol residue
equivalent thereto. The (meth)acryloyl group refers to an acryloyl
group or a methacryloyl group having an alcohol residue equivalent
thereto. The EO refers to ethylene oxide. The EO-modified compound
A refers to a compound in which a (meth)acrylic acid residue and an
alcohol residue of the compound A are bonded to each other through
the block structure of an ethylene oxide group. The PO refers to
propylene oxide. The PO-modified compound B refers to a compound in
which a (meth)acrylic acid residue and an alcohol residue of the
compound B are bonded to each other through the block structure of
a propylene oxide group.
Ohnishi Parameter of Component (A)
[0034] It is known that the dry etching speed V of a composition,
the total number of atoms N in a composition, the total number of
carbon atoms NC in a composition, and the total number of oxygen
atoms NO in a composition have the following relationship shown in
the following expression (1) (J. Electrochem. Soc., 130, p 143
(1983))
V.sub.OCN/N.sub.C-N.sub.O) (1)
[0035] In Expression (1), N/(N.sub.C-N.sub.O) is commonly referred
to as a "Ohnishi parameter". For example, PTL 1 describes a
technique of obtaining a photocurable composition having high dry
etching resistance by the use of a polymerizable compound component
having a small Ohnishi parameter.
[0036] According to Expression (1) above, it is suggested that
organic compounds having a smaller number of oxygen atoms or having
a larger number of aromatic ring structures or alicyclic structures
have smaller Ohnishi parameters and have high dry etching
resistance.
[0037] When the component (A) contains two or more kinds of
polymerizable compounds, the Ohnishi parameter is calculated using
the following expression (2) as the mole fraction weighted average
value.
OP=n.sub.1OP.sub.1+n.sub.2OP.sub.2+ . . . +n.sub.nOP.sub.n (2)
[0038] In this embodiment, the Ohnishi parameter of the component
(A) is suitably 3.2 or less. When the component (A) is configured
by a polymerizable compound in which the Ohnishi parameter is
smaller than 3.2, good dry etching resistance is obtained. On the
other hand, when the component (A) is configured by a polymerizable
compound in which the Ohnishi parameter is larger than 3.2, the dry
etching resistance is low, and therefore, a desired substrate
processing accuracy cannot be obtained in some cases, which may
lead to a reduction in yield.
Component (B): Photopolymerization Initiator
[0039] The component (B) is a photopolymerization initiator.
[0040] In this embodiment, the photopolymerization initiator is a
compound which detects light of a predetermined wavelength to cause
generation of the polymerization factor (radical). Specifically,
the photopolymerization initiator is a polymerization initiator
(radical generating agent) which generates a radical by light
(radiation rays, such as infrared rays, visible rays, ultraviolet
rays, far ultraviolet rays, X-rays, and charged particle beams,
such as electron beams).
[0041] The component (B) may be configured from one kind of
photopolymerization initiator or may be configured from two or more
kinds of photopolymerization initiators.
[0042] Examples of the radical generating agents include, for
example, 2,4,5-triaryl imidazole dimers which may have
substituents, such as a 2-(o-chlorophenyl)-4,5-diphenyl imidazole
dimer, a 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, a
2-(o-fluorophenyl)-4,5-diphenyl imidazole dimer, and a 2-(o- or
p-methoxyphenyl)-4,5-diphenyl imidazole dimer; Benzophenone
derivatives, such as benzophenone,
N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's Ketone),
N,N'-tetraethyl-4,4'-diaminobenzophenone,
4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone,
4,4'-dimethoxy benzophenone, and 4,4'-diaminobenzophenone;
.alpha.-amino aromatic ketone derivatives, such as
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,
2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propane-1-on;
quinones, such as 2-ethylanthraquinone, phenanthrene quinone,
2-t-butyl anthraquinone, octamethyl anthraquinone, 1,2-benz
anthraquinone, 2,3-benz anthraquinone, 2-phenylanthraquinone,
2,3-diphenyl anthraquinone, 1-chloroanthraquinone, 2-methyl
anthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone,
2-methyl-1,4-naphthoquinone, and 2,3-dimethyl anthraquinone;
benzoin ether derivatives, such as benzoin methyl ether, benzoin
ethyl ether, and benzoin phenyl ether; benzoin derivatives, such as
benzoin, methyl benzoin, ethyl benzoin, and propylbenzoin; benzyl
derivatives, such as benzyl dimethyl ketal; acridine derivatives,
such as 9-phenyl acridine and 1,7-bis(9,9'-acridinyl)heptane;
N-phenylglycine derivatives, such as N-phenylglycine; acetophenone
derivatives, such as acetophenone, 3-methyl acetophenone,
acetophenone benzyl ketal, 1-hydroxy cyclohexyl phenyl ketone, and
2,2-dimethoxy-2-phenyl acetophenone; thioxanthone derivatives, such
as thioxanthone, diethyl thioxanthone, 2-isopropyl thioxanthone,
and 2-chlorothioxanthone; acyl phosphine oxide derivatives, such as
2,4,6-trimethyl benzoyl diphenyl phosphine oxide,
bis(2,4,6-trimethyl benzoyl)phenyl phosphine oxide, and
bis-(2,6-dimethoxy benzoyl)-2,4,4-trimethyl pentyl phosphine oxide;
oxime ester derivatives, such as 1,2-octanedione,
1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone,
1-[9-ethyl-6-(2-methyl benzoyl)-9H-carbazole-3-yl]-, and
1-(o-acetyl oxime); xanthone, fluorenone, benzaldehyde, fluorene,
anthraquinone, triphenyl amine, carbazole,
1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-on,
2-hydroxy-2-methyl-1-phenyl propane 1-on, and the like but the
radical generating agents are not limited thereto.
[0043] Examples of commercially-available items of the radical
generating agent include Irgacure 184, 369, 651, 500, 819, 907,
784, 2959, CGI-1700, -1750, -1850, and CG24-61, Darocur 1116 and
1173, Lucirin TPO, LR8893, and LR8970 (all manufactured by BASF),
Uvecryl P36 (manufactured by UCB), and the like but the
commercially-available items are not limited thereto.
[0044] Among the above, the component (B) of the photocurable
composition for nanoimprint is suitably an acylphosphine oxide
polymerization initiator.
[0045] Among the examples above, the acyl phosphine oxide
polymerization initiator is an acyl phosphine oxide compound, such
as 2,4,6-trimethyl benzoyl diphenyl phosphine oxide,
bis(2,4,6-trimethyl benzoyl)phenyl phosphine oxide, or
bis(2,6-dimethoxy benzoyl)-2,4,4-trimethyl pentyl phosphine
oxide.
[0046] The compounding ratio of the component (B) which is a
photopolymerization initiator in the photocurable composition for
nanoimprint is suitably 0.01% by weight or more and 10% by weight
or less and more suitably 0.1% by weight or more and 7% by weight
or less based on the total amount of the component (A) which is a
polymerizable compound.
[0047] By setting the compounding ratio of the component (B) to
0.01% by weight or more based on the total amount of the
polymerizable compound, the curing rate of a composition increases
and the reaction efficiency can be improved. By setting the
compounding ratio of the component (B) to 10% by weight or less
based on the total amount of the polymerizable compound, the
photocured film to be obtained is a photocured film having a
certain degree of mechanical strength.
Other Additive Components (C)
[0048] The photocurable composition for nanoimprint of this
embodiment may contain further additive components (C) in addition
to the component (A) and the component (B) described above
according to various purposes insofar as the effects of the present
invention are not impaired. Examples of such additive components
(C) include a sensitizer, a hydrogen donor, an internal mold
release agent, a surfactant, an antioxidant, a solvent, a polymer
component, and a polymerization initiator which is not the
component (B), and the like.
[0049] The sensitizer is a compound to be added as appropriate for
the purpose of promoting the polymerization reaction and improving
the reaction conversion rate. As the sensitizer, a sensitizing dye
and the like are mentioned, for example.
[0050] The sensitizing dye is a compound which is excited by
absorbing light of a specific wavelength and interacts with the
photopolymerization initiator which is the component (B). The
interaction described herein is energy transfer, electron transfer,
and the like from the sensitizing dye in the excited state to the
photopolymerization initiator which is the component (B).
[0051] Specific examples of the sensitizing dye include an
anthracene derivative, an anthraquinone derivative, a pyrene
derivative, a perylene derivative, a carbazole derivative, a
benzophenone derivative, a thioxanthone derivative, a xanthone
derivative, a coumarin derivative, a phenothiazine derivative, a
camphorquinone derivative, an acridine dye, a thiopyrylium salt
dye, a merocyanine dye, a quinoline dye, a styryl quinoline dye, a
ketocoumarin dye, a thioxanthene dye, a xanthene dye, an oxonol
dye, a cyanine dye, a rhodamine dye, a pyrylium salt dye, and the
like but the sensitizing dye is not limited thereto.
[0052] The sensitizers may be used alone or as a mixture of two or
more kinds thereof.
[0053] The hydrogen donor is a compound which reacts with an
initiation radical generated from the photopolymerization initiator
which is the component (B) or a radical at the polymerization
growth terminal to generate a radical having higher reactivity. It
is suitable to add the hydrogen donor when the photopolymerization
initiator which is the component (B) is a photoradical generating
agent.
[0054] Specific examples of such a hydrogen donor include amine
compounds, such as n-butylamine, di-n-butylamine, tri-n-butyl
phosphine, allylthio urea, s-benzyl isothiuronium-p-toluene
sulfinate, triethyl amine, diethyl amino ethyl methacrylate,
triethylene tetramine, 4,4'-bis(dialkyl amino)benzophenone,
N,N-dimethylamino benzoic acid ethyl ester, N,N-dimethylamino
benzoic acid isoamyl ester, pentyl-4-dimethylamino benzoate,
triethanol amine, and N-phenylglycine, mercapto compounds, such as
2-mercapto-N-phenyl benzimidazole and mercaptopropionic acid ester,
and the like but the hydrogen donor is not limited thereto.
[0055] The hydrogen donors may be used alone or as a mixture of two
or more kinds thereof.
[0056] The hydrogen donor may have a function as a sensitizer.
[0057] When the photocurable composition for nanoimprint of this
embodiment contains the sensitizer or the hydrogen donor as the
additive component (C), the content of each of the sensitizer and
the hydrogen donor is suitably 0.1% by weight or more and 20% by
weight or less, more suitably 0.1% by weight or more and 5.0% by
weight or less, and still more suitably 0.2% by weight or more and
2.0% by weight or less based on the total amount of the component
(A) which is the polymerizable compound. When the sensitizer is
contained in a proportion of 0.1% by weight or more based on the
total amount of the component (A), the polymerization promotion
effect can be more effectively demonstrated. By setting the content
of the sensitizer or the hydrogen donor to 5.0% by weight or less,
the molecular weight of a high molecular weight compound
configuring a photocured film to be produced becomes sufficiently
high and also poor dissolution in the photocurable composition for
nanoimprint or degradation of the storage stability of the
photocurable composition for nanoimprint can be suppressed.
[0058] For the purpose of reducing the interface bonding force
between a mold and a resist, i.e., a reduction in mold releasing
force in a mold release step, an internal mold release agent can be
added to the photocurable composition for nanoimprint. In this
specification, the internal type means that the mold release agent
is added to a curable composition in advance before an arrangement
step of the photocurable composition for nanoimprint.
[0059] As the internal mold release agent, surfactants, such as a
silicone based surfactant, a fluorine based surfactant, and a
hydrocarbon based surfactant, and the like can be used. In this
embodiment, the internal mold release agent does not have
polymerizability.
[0060] The fluorine based surfactant includes polyalkylene oxide
(polyethylene oxide, polypropylene oxide, and the like) adducts of
alcohols having a perfluoro alkyl group), polyalkylene oxides
(polyethylene oxide, polypropylene oxide, and the like) adducts of
perfluoropolyether, and the like. The fluorine based surfactant may
have a hydroxyl group, an alkoxy group, an alkyl group, an amino
group, a thiol group, and the like in a part of the molecular
structure (for example, terminal group).
[0061] As the fluorine based surfactant, commercially-available
items may be used. Examples of the commercially-available items
include, for example, Megafac F-444, TF-2066, TF-2067, and TF-2068
(all manufactured by DIC), Fluorad FC-430 and FC-431 (all
manufactured by Sumitomo 3M Limited), Surflon S-382 (manufactured
by AGC), EFTOP EF-122A, 122B, 122C, EF-121, EF-126, EF-127, and
MF-100 (all manufactured by Tokem Products Co., Ltd.), PF-636,
PF-6320, PF-656, and PF-6520 (all manufactured by OMNOVA
Solutions), Unidyne DS-401, DS-403, and DS-451 (all manufactured by
Daikin Industries), Ftergent 250, 251, 222F, and 208G (all
manufactured by NEOS Co. Ltd.), and the like.
[0062] The internal mold release agent may be a hydrocarbon based
surfactant.
[0063] The hydrocarbon based surfactant includes alkylalcohol
polyalkylene oxide adducts obtained by adding alkylene oxide having
2 to 4 carbon atoms to alkyl alcohols having 1 to 50 carbon atoms
and the like.
[0064] Examples of the alkylalcohol polyalkylene oxide adducts
include a methyl alcohol ethylene oxide adduct, a decyl alcohol
ethylene oxide adduct, a lauryl alcohol ethylene oxide adduct, a
cetyl alcohol ethylene oxide adduct, a stearyl alcohol ethylene
oxide adduct, a stearyl alcohol ethylene oxide/propylene oxide
adduct, and the like. The terminal group of the alkylalcohol
polyalkylene oxide adduct is not limited to a hydroxyl group which
can be produced by simply adding polyalkylene oxide to alkyl
alcohol. The hydroxyl group may be converted to other substituents,
e.g., polar functional groups, such as a carboxyl group, an amino
group, a pyridyl group, a thiol group, and a silanol group, and
hydrophobic functional groups, such as an alkyl group and an alkoxy
group.
[0065] As the alkylalcohol polyalkylene oxide adduct,
commercially-available items may be used. Examples of the
commercially-available items include for example, polyoxy ethylene
methyl ether (methyl alcohol ethylene oxide adduct) (BLAUNON
MP-400, MP-550, and MP-1000) manufactured by AOKI OIL INDUSTRIAL
Co., LTD., polyoxy ethylene decyl ether (decyl alcohol ethylene
oxide adduct) (FINESURF D-1303, D-1305, D-1307, and D-1310)
manufactured by AOKI OIL INDUSTRIAL Co., LTD., polyoxy ethylene
lauryl ether (lauryl alcohol ethylene oxide adduct) (BLAUNON
EL-1505) manufactured by AOKI OIL INDUSTRIAL Co., LTD., polyoxy
ethylene cetylether (cetyl alcohol ethylene oxide adduct) (BLAUNON
CH-305 and CH-310) manufactured by AOKI OIL INDUSTRIAL Co., LTD.,
polyoxy ethylene stearyl ether (stearyl alcohol ethylene oxide
adduct) (BLAUNON SR-705, SR-707, SR-715, SR-720, SR-730, and
SR-750) manufactured by AOKI OIL INDUSTRIAL Co., LTD., random
polymerization type polyoxy ethylene polyoxypropylene stearyl ether
(BLAUNON SA-50/50 1000R and SA-30/70 2000R) manufactured by AOKI
OIL INDUSTRIAL Co., LTD., polyoxy ethylene methyl ether (Pluriol
A760E) manufactured by BASF, polyoxyethylene alkyl ether
manufactured by Kao Corporation (EMULGEN series), and the like.
[0066] Among the hydrocarbon based surfactants, the internal mold
release agent is suitably an alkylalcohol polyalkylene oxide adduct
and more suitably a long chain alkylalcohol polyalkylene oxide
adduct.
[0067] The internal mold release agents may be used alone or as a
mixture of two or more kinds thereof.
[0068] When the photocurable composition for nanoimprint of this
embodiment contains the internal mold release agent as the additive
component (C), the content of the internal mold release agent is
0.001% by weight or more and 10% by weight or less based on the
total amount of the component (A) which is the polymerizable
compound. The content is suitably 0.01% by weight or more and 7% by
weight or less and more suitably 0.05% by weight or more and 5% by
weight or less.
[0069] By analyzing the photocurable composition for nanoimprint of
this embodiment and/or a photocured film obtained by curing the
same by infrared spectroscopy, ultraviolet-visible spectroscopy,
Pyrolysis-Gas Chromatography/Mass spectrometry, or the like, the
proportions of the component (A) and the component (B) can be
determined, and consequently the proportions of the component (A)
and the component (B) in the photocurable composition for imprint
can be determined. Also when the additive component (C) is
contained, the proportions of the component (A), the component (B),
and the additive component (C) in the photocurable composition for
imprint can be similarly determined.
Glass Transition Temperature of Photocurable Composition for
Imprint
[0070] The glass transition temperature of a photocured substance
of the photocurable composition for imprint of this embodiment is
suitably 90.degree. C. or more and more suitably 120.degree. C. or
more. It is considered that, by setting the glass transition
temperature to 90.degree. C. or more, thermal expansion and thermal
distortion in dry etching are hard to occur.
[0071] As a method for measuring the glass transition temperature
of the photocured substance, the glass transition temperature can
be measured using differential scanning calorimeter (DSC) or a
dynamic viscoelasticity device.
[0072] For example, when the glass transition temperature is
measured using DSC, the extrapolation glass transition initiating
temperature (Tig) is determined from the intersection of the
straight line obtained by extending the baseline (DSC curve portion
in a temperature region where transition and a reaction does not
occur in a test piece) on the low temperature side of the DSC curve
of the photocured substance to the high temperature side and the
tangent drawn in such a manner that the gradient of the curve of a
step-like change portion of the glass transition reaches the
maximum, and then the extrapolation glass transition start
temperature (Tig) can be determined as the glass transition
temperature. As a main device, STA-6000 (manufactured by Perkin
Eimer) and the like are mentioned.
[0073] On the other hand, when the transition temperature is
measured using a dynamic viscoelasticity device, the temperature at
which the loss tangent (tan .delta.) of the photocured substance
reaches the maximum is defined as the glass transition temperature.
As a main device capable of measuring the dynamic viscoelasticity,
MCR301 (manufactured by Anton Paar) and the like are mentioned.
[0074] In the present invention, it may be able to be confirmed
that the glass transition temperature is 90.degree. C. or more by
any one of the measuring methods described above. A photocurable
composition having a glass transition temperature of 90.degree. C.
or more in the measurement of the loss tangent using a dynamic
viscoelasticity device is suitable. The dynamic viscoelasticity
device can consistently perform the production of the photocured
substance and the measurement of the glass transition temperature
and further the measurement of the coefficient of thermal expansion
described later.
[0075] Depending on the composition of the photocurable
composition, due to the fact that a photopolymerization initiator
having high absorption in the exposure wavelength (for example,
around 365 nm) to be used in the dynamic viscoelasticity device is
contained, the transmittance to a 0.1 .mu.m thick photocured film
decreases, so that the glass transition temperature cannot be
measured with good accuracy in some cases. Specifically, the
measurement becomes difficult when the transmittance is 30% or
less.
[0076] In this case, it can be confirmed by the following method
that the photocurable composition for imprint has a glass
transition temperature of 90.degree. C. or more.
[0077] 3 parts by weight of Lucirin TPO which is a
photopolymerization initiator (B) having low influence on a
reduction in transmittance based on 100 parts by weight of the
photopolymerizable compound (A) to be used is compounded to produce
a photocurable composition, and then the loss tangent tan .delta.
of a photocured film is measured while increasing the temperature.
Then, due to the fact that the temperature at which the tan .delta.
reaches the maximum is 90.degree. C. or more, it can be specified
that the glass transition temperature of the photocurable
composition is 90.degree. C. or more.
[0078] The composition of the photopolymerizable compound (A) is
the main factor of determining the glass transition temperature.
The influence of the photopolymerization initiator of a small
content on the glass transition temperature of the photocurable
composition (B) is low. Therefore, it can be specified by carrying
out the measuring method described above that the glass transition
temperature of the photocurable composition is 90.degree. C. or
more.
Temperature in Compounding Photocurable Composition for Imprint
[0079] When preparing the photocurable composition for imprint of
this embodiment, at least the component (A) and the component (B)
are mixed and dissolved under predetermined temperature conditions.
Specifically, the mixing and the dissolution are carried out in the
range of 0.degree. C. or more and 100.degree. C. or less. The same
applies to the case where the additive component (C) is
contained.
Viscosity of Photocurable Composition for Imprint
[0080] The viscosity at 23.degree. C. of a mixture of the
components except a solvent of the photocurable composition for
imprint of this embodiment is suitably 1 mPa*s or more and 100
mPa*s or less, more suitably 3 mPa*s or more and 50 mPa*s or less,
and still more suitably 5 mPa*s or more and 12 mPa*s or less.
[0081] By setting the viscosity of the photocurable composition for
imprint to 100 mPa*s or less, when the photocurable composition for
imprint is brought into contact with a mold, the time required for
the composition to fill into concave portions of a fine pattern on
the mold is not prolonged. More specifically, the optical imprint
method can be carried out with high productivity. Moreover, pattern
defects due to poor filling are hard to occur.
[0082] By setting the viscosity to 1 mPa*s or more, when the
photocurable composition for imprint is applied onto a substrate,
application unevenness is hard to occur and, when the photocurable
composition for imprint is brought into contact with a mold, the
photocurable composition for imprint is difficult to flow out of
end portions of the mold.
Surface Tension of Photocurable Composition for Imprint
[0083] With respect to the surface tension of the photocurable
composition for imprint of this embodiment, the surface tension at
23.degree. C. of the mixture of the components except a solvent is
suitably 5 mN/m or more and 70 mN/m or less, more suitably 7 mN/m
or more and 35 mN/m or less, and still more suitably 10 mN/m or
more and 32 mN/m or less. Herein, by setting the surface tension to
5 mN/m or more, when the photocurable composition for imprint is
brought into contact with a mold, the time required for the
composition to fill into concave portions of a fine pattern on the
mold is not prolonged.
[0084] By setting the surface tension to 70 mN/m or less, a
photocured film obtained by curing the photocurable composition for
imprint is a photocured film having surface smoothness.
Impurities Mixed in Photocurable Composition for Imprint
[0085] It is suitable for the photocurable composition for imprint
of this embodiment not to contain impurities as much as possible.
The impurities described herein mean substances other than the
component (A), the component (B), and the additive component (C)
described above.
[0086] Therefore, the photocurable composition for imprint is
suitably one obtained passing through a purification step. As such
a purification step, filtration using a filter or the like are
suitable.
[0087] Specifically, when performing the filtration using a filter,
it is suitable that the component (A), the component (B), and the
additive component to be added as necessary described above are
mixed, and then the mixture is filtered with a filter having a pore
size of 0.001 .mu.m or more and 5.0 .mu.m or less. When performing
the filtration using a filter, it is more suitable to perform the
filtration in many stages or to repeat the filtration many times.
The filtered liquid may be filtered again. A plurality of filters
having different pore sizes may be used. As the filter for use in
the filtration, filters formed of polyethylene resin, polypropylene
resin, fluororesin, nylon resin, and the like can be used but the
filter is not particularly limited thereto.
[0088] By passing through such a purification step, impurities,
such as particles, mixed in the photocurable composition for
imprint, can be removed. Thus, pattern defects caused by
irregularities accidentally formed in a photocured film, which is
obtained after curing the photocurable composition for imprint, due
to the impurities, such as particles, can be prevented.
[0089] When the photocurable composition for imprint of this
embodiment is used for manufacturing a semiconductor integrated
circuit, it is suitable to avoid the mixing of impurities (metal
impurities) containing metal atoms into the photocurable
composition for imprint as much as possible in order not to inhibit
an operation of a product. In such a case, the concentration of the
metal impurities contained in the photocurable composition for
imprint is adjusted to suitably 10 ppm or less and more suitably
100 ppb or less.
[0090] As described above, the present invention can take various
aspects but suitably takes an aspect containing at least either the
following item (A) or (B):
(A) The polymerizable compound (A) at least contains 40% by weight
or more of a multifunctional (meth)acrylic monomer and the glass
transition temperature of a photocured substance of a photocurable
composition is 120.degree. C. or more; or (B) The multifunctional
acrylic monomer contained in the polymerizable compound (A) is any
one of m-xylylene diacrylate, phenyl ethylene glycol diacrylate,
and 2-phenyl-1,3-propanediol diacrylate.
Method for Producing Film Having Pattern Shape
[0091] Next, a method for producing a film having a pattern shape
of this embodiment is described. FIGS. 1A to 1G are schematic cross
sectional views illustrating an example of the method for producing
a film having a pattern shape of this embodiment.
[0092] The method for producing a film having a pattern shape of
this embodiment has:
[1] an arrangement step of arranging the photocurable composition
for imprint of the embodiment described above on a substrate; [2] a
mold contact step of bringing the photocurable composition for
imprint into contact with a mold; [3] an alignment step of aligning
the positions of the mold and a substrate to be processed; [4] a
light irradiation step of irradiating the photocurable composition
for imprint with light; and [5] a releasing step of releasing the
photocured film obtained by the step [4] and the mold from each
other.
[0093] The method for producing a photocured film having a pattern
shape of this embodiment is a method for producing a film utilizing
the optical imprint method.
[0094] The photocured film obtained by the method for producing a
photocured film having a pattern shape of this embodiment is
suitably a film having a pattern of a size 1 nm or more and 10 mm
or less and more suitably a film having a pattern of a size of 10
nm or more and 100 .mu.m or less. In general, a pattern formation
technique of producing a film having a pattern (irregular
structure) of a nano size (1 nm or more 100 nm or less) utilizing
light is referred to as an optical nanoimprint method. The method
for producing a photocured film having a pattern shape of this
embodiment employs the optical nanoimprint method.
[0095] Hereinafter, each step is described.
[Arrangement Step [1]]
[0096] In this step (arrangement step), a photocurable composition
for imprint 101 of this embodiment described above is arranged
(applied) on a substrate 102 to form a coating film as illustrated
in FIG. 1A.
[0097] The substrate 102 which is a target on which the
photocurable composition for imprint 101 is to be arranged is a
substrate to be processed and a silicon wafer is usually used.
[0098] In this embodiment, however, the substrate 102 is not
limited to the silicon wafer and may be arbitrarily selected from
those known as substrates for semiconductor devices, such as
aluminum, a titanium-tungsten alloy, an aluminum-silicon alloy, an
aluminum-copper-silicon alloy, silicon oxide, silicon nitride, and
the like for use. For the substrate 102 to be used (substrate to be
processed), a substrate whose adhesiveness with the photocurable
composition for imprint is improved by surface treatment, such as
silane coupling treatment, silazane treatment, and film formation
of an organic thin film.
[0099] In this embodiment, as a method for arranging the
photocurable composition for imprint on the substrate to be
processed, for example, an ink jet method, a dip coating method, an
air knife coating method, a curtain coating method, a wire bar
coating method, a gravure coating method, an extrusion coating
method, a spin coating method, a slit scan method, and the like can
be used. In the optical imprint method, the ink jet method is
particularly suitable. The film thickness of a layer to which a
shape is to be transferred (coating film) varies depending on the
intended use and is 0.01 .mu.m or more and 100.0 .mu.m or less, for
example.
[Mold Contact Step [2]]
[0100] Next, as illustrated in FIGS. 1B(b-1) and 1B(b-2), a mold
104 having an original pattern for transferring a pattern shape is
brought into contact with the coating film containing the
photocurable composition for imprint 101 formed in the previous
step (arrangement step). By bringing the mold 104 into contact with
the photocurable composition 101 for imprint (layer to which a
shape is to be transferred) in this step (FIG. 1B(b-1)), the
coating film (partially) containing the photocurable composition
for imprint 101 is filled into concave portions of a fine pattern
on the surface of the mold 104, so that a coating film 106 filled
into the fine pattern of the mold is obtained (FIG. 1B(b-2)).
[0101] The mold 104 is required to contain a light-transmitting
material in consideration of the following step (light irradiation
step). The constituent material of the mold 104 is specifically
suitably a light transparent resin, such as glass, quartz, PMMA, or
polycarbonate resin, a flexible film, such as a transparent metal
vapor deposition film or polydimethyl siloxane, a photocured film,
a metal film, or the like. However, when the light transparent
resin is used as the constituent material of the mold 104, it is
necessary to select a resin which does not dissolve in the
components contained in the photocurable composition for imprint
101. Quartz is particularly suitable because the thermal expansion
coefficient is low and pattern distortion is small.
[0102] The fine pattern on the surface of the mold 104 suitably has
a pattern height of 4 nm or more and 200 nm or less and an aspect
ratio of 1 or more and 10 or less.
[0103] In order to increase the releasability of the photocurable
composition for imprint 101 and the surface of the mold 104, the
mold 104 may be surface treated before this step which is the mold
contact step of the photocurable composition for imprint and the
mold. As the surface treatment method, a method including applying
a mold release agent to the surface of the mold to form a mold
release agent layer is mentioned. Herein, examples of the mold
release agent to be applied to the surface of the mold include a
silicone mold release agent, a fluorine mold release agent, a
hydrocarbon mold release agent, a polyethylene mold release agent,
a polypropylene mold release agent, a paraffin mold release agent,
a montan mold release agent, a carnauba mold release agent, and the
like. For example, a commercially-available coating type mold
release agent, such as Optool DSX manufactured by Daikin
Industries, LTD. can also be suitably used. The mold release agents
may be used alone or in combination of two or more kinds thereof.
Among the above, the fluorine mold release agent and the
hydrocarbon mold release agent are particularly suitable.
[0104] In this step (mold contact step), when the mold 104 and the
photocurable composition for imprint 101 are brought into contact
with each other as illustrated in FIG. 1B(b-1), the pressure to be
applied to the photocurable composition for imprint 101 is not
particularly limited and is usually 0 MPa or more and 100 MPa or
less. In particular, the pressure is suitably 0 MPa or more and 50
MPa or less, more suitably 0 MPa or more and 30 MPa or less, and
still more suitably 0 MPa or more and 20 MPa or less.
[0105] The period of time while the mold 104 is brought into
contact with the photocurable composition for imprint 101 in this
step is not particularly limited and is usually 0.1 second or more
and 600 seconds or less, suitably 0.1 second or more and 300
seconds or less, still more suitably 0.1 second or more and 180
seconds or less, and particularly suitably 0.1 second or more and
120 seconds or less.
[0106] This step can also be performed under any condition of under
an air atmosphere, under reduced pressure atmosphere, and under an
inactive gas atmosphere and the reduced pressure atmosphere or the
inactive gas atmosphere is suitable because influence of oxygen or
moisture on the curing reaction can be prevented. Specific examples
of the inactive gas usable when performing this step under the
inactive gas atmosphere include nitrogen, carbon dioxide, helium,
argon, various kinds of fluorocarbon gas, and the like or a mixed
gas thereof. When performing this step under a specific gas
atmosphere including the air atmosphere, a suitable pressure is
0.0001 atm or more and 10 atm or less.
[0107] The mold contact step may be performed under an atmosphere
containing condensable gas (hereinafter referred to as a
condensable gas atmosphere). The condensable gas in this
specification refers to gas which is condensed and liquefied by the
capillary pressure generated when the gas in the atmosphere is
filled into the concave portions of the fine pattern formed on the
mold 104 and a gap between the mold and the substrate together with
the coating film (partially) 106. The condensable gas is present in
the form of gas in the atmosphere before the photocurable
composition 101 (layer to which a shape is to be transferred) and
the mold 104 are brought into contact with each other in the mold
contact step (FIG. 1B(b-1)).
[0108] When the mold contact step is performed under the
condensable gas atmosphere, air bubbles disappear due to the
liquefaction of the gas filled into the concave portions of the
fine pattern, and thus the filling properties are excellent. The
condensable gas may dissolve in the photocurable composition
101.
[0109] The boiling point of the condensable gas is not particularly
limited insofar as the boiling point is equal to or less than the
atmospheric temperature of the mold contact step and is suitably
-10.degree. C. to 23.degree. C. and more suitably 10.degree. C. to
23.degree. C. When the boiling point is in this range, the filling
properties are more excellent.
[0110] The vapor pressure of the condensable gas at the atmospheric
temperature in the mold contact step is not particularly limited
insofar as the vapor pressure is equal to or less than the mold
pressure when impressed in the mold contact step and is suitably
0.1 to 0.4 MPa. When the vapor pressure is in this range, the
filling properties are more excellent. When the vapor pressure at
the atmospheric temperature is larger than 0.4 MPa, there is a
tendency that the effect that air bubbles disappear cannot be
sufficiently obtained. On the other hand, when the vapor pressure
at the atmospheric temperature is smaller than 0.1 MPa, the
pressure needs to be reduced, so that there is a tendency for a
device to be complicated.
[0111] The atmospheric temperature of the mold contact step is not
particularly limited and is suitably 20.degree. C. to 25.degree.
C.
[0112] Specific examples of the condensable gas include
chlorofluocarbon, such as: chlorofluorocarbon (CFC), such as
trichlorofluoro methane, hydrofluorocarbon (HFC), such as
fluorocarbon (FC), hydrochlorofluorocarbon (HCFC), and
1,1,1,3,3-pentafluoro propane (CHF.sub.2CH.sub.2CF.sub.3,HFC-245fa,
PFP), and hydrofluoro ether (HFE), such as pentafluoroethyl methyl
ether (CF.sub.3CF.sub.2OCH.sub.3, HFE-245mc).
[0113] Among the above, from the viewpoint that the filling
properties at an atmospheric temperature of 20.degree. C. to
25.degree. C. in the mold contact step are excellent,
1,1,1,3,3-pentafluoro propane (Vapor pressure at 23.degree. C. of
0.14 MPa, Boiling point of 15.degree. C.), trichlorofluoro methane
(Vapor pressure at 23.degree. C. of 0.1056 MPa, Boiling point of
24.degree. C.), and pentafluoroethyl methyl ether are suitable.
From the viewpoint that the safety is excellent,
1,1,1,3,3-pentafluoro propane is particularly suitable.
[0114] The condensable gas may be used alone or as a mixture of two
or more kinds thereof. The condensable gas may be mixed with
non-condensable gas, such as air, nitrogen, carbon dioxide, helium,
and argon for use. The non-condensable gas to be mixed with the
condensable gas is suitably helium from the viewpoint of the
filling properties. Helium can permeate the mold 104. Therefore,
when the gas (condensable gas and helium) in the atmosphere is
filled into the concave portions of the fine pattern formed on the
mold 104 together with the coating film (partially) 106 in the mold
contact step, the condensable gas is liquefied and also helium
permeates the mold.
[Alignment Step [3]]
[0115] Next, as illustrated in FIG. 1C, the positions of the mold
and/or the substrate to be processed are adjusted in such a manner
that a mold side aligning mark 105 and an aligning mark 103 of the
substrate to be processed are in agreement with each other.
[Light Irradiation Step [4]]
[0116] Next, a contact portion with the mold of the photocurable
composition for imprint, in detail the coating film 106 filled into
the fine pattern of the mold, is irradiated with light through the
mold 104 in the state where the positions are aligned in the step
[3] as illustrated in FIG. 1D (FIG. 1D(d-1)). Thus, the coating
film 106 filled into the fine pattern of the mold 104 is cured by
the emitted light to be a photocured film 108 (FIG. 1D(d-2)).
[0117] Herein, the light irradiating the photocurable composition
for imprint 101 configuring the coating film 106 filled into the
fine pattern of the mold is selected according to the sensitivity
wavelength of the photocurable composition for imprint 101.
Specifically, it is suitable to select ultraviolet light of a
wavelength of 150 nm or more and 400 nm or less, X-rays, electron
beams, or the like as appropriate for use.
[0118] Among the above, the light (irradiation light 107)
irradiating the photocurable composition for imprint 101 is
particularly suitably ultraviolet light. This is because those
commercially available as a curing assistant (photopolymerization
initiator) are compounds having sensitivity in ultraviolet light in
many cases. Herein, examples of a light source emitting ultraviolet
light include, for example, a high pressure mercury lamp, an
ultrahigh pressure mercury lamp, a low pressure mercury lamp, a
Deep-UV lamp, a carbon arc light, a chemical lamp, a metal halide
lamp, a xenon lamp, a KrF excimer laser, an ArF excimer laser, an
F.sub.2 excimer laser, and the like and the ultrahigh pressure
mercury lamp is particularly suitable. The number of the light
sources to be used may be one or two or more. When performing the
light irradiation, the light irradiation may be performed to the
entire surface of the coating film 106 or only to a partial region
thereof.
[0119] The light irradiation may be intermittently performed to the
entire region on the substrate two or more times or may be
continuously performed to the entire region. Or, a partial region A
may be irradiated with light in a first irradiation step, and then
a region B different from the region A may be irradiated with light
in a second irradiation step.
[Mold Release Step [5]]
[0120] Next, the photocured film 108 and the mold 104 are released
from each other. In this case, a photocured film 109 having a
predetermined pattern shape is formed on the substrate 102.
[0121] In this step (mold release step), the photocured film 108
and the mold 104 are released from each other, and then the
photocured film 109 having a pattern shape serving as a reversal
pattern of the fine pattern formed on the mold 104 is obtained in
the step [4] (light irradiation step) as illustrated in FIG.
1E.
[0122] By a series of steps (manufacturing step) having the step
[1] to step [5] above, the photocured film having a desired
irregular pattern shape (pattern shape following the irregular
shape of the mold 104) at a desired position can be obtained. The
obtained photocured film can also be utilized as optical members
(including the case where the photocured film is used as one member
of an optical member), such as a Fresnel lens and a diffraction
grating, for example. In such a case, the photocured film can be
used as an optical member at least having the substrate 102 and the
photocured film 109 having a pattern shape arranged on the
substrate 102.
[0123] According to the method for producing a film having a
pattern shape of this embodiment, a repetition unit (shot)
including the step [1] to the step [5] can be repeatedly performed
two or more times on the same substrate to be processed. By
repeating the repetition unit (shot) including the process [1] to
the process [5] two or more times, a photocured film having a
plurality of desired irregular pattern shapes (pattern shape
following the irregular shape of the mold 104) at desired positions
of the substrate to be processed can be obtained.
[Remaining Film Removal Step [6] of Removing a Part of Photocured
Film]
[0124] The photocured film obtained by the mold release process
which is the process [5] has a specific pattern shape but the
photocured films may partially remain also in regions other than
the region where the pattern shape is formed (in the following
description, such a part of the photocured film is sometimes
referred to as a remaining film). In such a case, the obtained
photocured film (remaining film) in the region to be removed of the
photocured film having the pattern shape is removed, whereby a
photocured film pattern 110 having a desired irregular pattern
shape (pattern shape following the irregular shape of the mold 104)
can be obtained as illustrated in FIG. 1F.
[0125] Herein, as a method for removing the remaining film, a
method removing the photocured film (remaining film) serving as the
concave portions of the photocured film 109 by a method, such as
etching, for example, to expose the surface of the substrate 102 in
the concave portions of the pattern of the photocured film 109 is
mentioned.
[0126] When the photocured film in the concave portions of the
photocured film 109 is removed by etching, a specific method
therefor is not particularly limited and known methods, e.g., dry
etching, can be used. For the dry etching, a known dry etching
device can be used. A sauce gas in the dry etching is selected as
appropriate according to the element composition of the photocured
film which is to be etched and halogen gas, such as CF.sub.4,
C.sub.2F.sub.6, C.sub.3F.sub.8, CCl.sub.2F.sub.2, CCl.sub.4,
CBrF.sub.3, BCl.sub.3, PCl.sub.3, SF.sub.6, and Cl.sub.2, gas
containing oxygen atoms, such as O.sub.2, CO, and CO.sub.2,
inactive gas, such as He, N.sub.2, and Ar, and gas, such as H.sub.2
and NH.sub.3, and the like can be used. The gas can also be mixed
for use.
[0127] By the manufacturing step including the step [1] to the step
[6] above, the photocured film pattern 110 having a desired
irregular pattern shape (pattern shape following the irregular
shape of the mold 104) at desired positions can be obtained and
articles having the photocured film pattern can be obtained. When
the substrate 102 is processed using the obtained photocured film
pattern 110, a substrate processing step (Step [7]) described later
is performed.
[0128] On the other hand, the obtained photocured film pattern 110
can be utilized as optical members (including the case where the
photocured film pattern 110 is used as one member of an optical
member), such as a diffraction grating and a polarizing plate, and
then an optical component can also be obtained. In such a case, an
optical component at least having the substrate 102 and the
photocured film pattern 110 arranged on the substrate 102 can be
obtained.
[Substrate Processing Step [7]]
[0129] The photocured film pattern 110 having an irregular pattern
shape which is obtained by the method for producing a photocured
film having a pattern shape of this embodiment can also be used as,
for example, a film for interlayer insulation film contained in
electronic components typified by semiconductor devices, such as
LSI, System LSI, DRAM, SDRAM, RDRAM, and D-RDRAM, and can also be
used as a resist film in manufacturing semiconductor devices.
[0130] When the photocured film pattern 110 is utilized as a resist
film, etching or ion implantation is performed to a part of the
substrate exposed in the etching step which is Step [6](region
denoted by the reference numeral 111 in FIG. 1F). In this case, the
photocured film pattern 110 functions as an etching mask. In
addition thereto, by configuring electronic components, a circuit
structure 112 (FIG. 1G) based on the pattern shape of the
photocured film pattern 110 can be formed on the substrate 102.
Thus, a circuit board to be utilized in semiconductor devices and
the like can be manufactured. By connecting the circuit board and a
circuit control mechanism of the circuit board, electronic devices,
such as displays, cameras, and medical devices, can also be
configured.
[0131] Similarly, optical components can also be obtained by
performing etching or ion implantation utilizing the photocured
film pattern 110 as a resist film.
[0132] When producing substrates with a circuit and electronic
components, the photocured film pattern 110 may be finally removed
from the processed substrate but a configuration in which the
photocured film pattern 110 may be left as a member configuring an
element may be acceptable.
Other Embodiments
[0133] The photocured film formed by the method is suitable for the
use in which the photocured film is processed by a dry etching
step. More specifically, the photocured film is useful as a
photocured film for dry etching to be used for a dry etching
process which is obtained by curing the photocurable composition
for imprint on a substrate.
[0134] By passing through the steps described above, a
semiconductor substrate pretreated by dry etching having a
semiconductor substrate and the photocured film for dry etching
patterned on the semiconductor substrate can be provided.
EXAMPLES
[0135] Hereinafter, the present invention is described in detail
with reference to Examples but the technical scope of the present
invention is not limited to Examples described below. "Part(s)"
used in the following description is a unit based on weight (part
by weight) unless otherwise particularly specified.
[0136] Reagents (polymerizable compounds, polymerization
initiators) used in any one of Examples and Comparative Examples
and contained in photocurable compositions for imprint are
mentioned below.
[0137] (A) Polymerizable Compound
<A1> Isobornyl acrylate (manufactured by Kyoeisha Chemical
Co., Ltd., Trade name: IB-XA) <A2> Benzyl acrylate
(manufactured by Osaka Organic Chemical Industry Co., Ltd., Trade
name: V #160) <A3> Dicyclopentanyl acrylate (manufactured by
Hitachi Chemical Co., Ltd., Trade name: FA-513AS)
<A4>2-naphthyl methyl acrylate (manufactured by NARD
institute, Ltd.) <A5> Diphenyl methanol acrylate
(manufactured by NARD institute, Ltd.) <A6>1,6-hexanediol
diacrylate (manufactured by Osaka Organic Chemical Industry Co.,
Ltd., Trade name: V #230) <A7>1,10-decanediol diacrylate
(manufactured by Osaka Organic Chemical Industry Co., Ltd., Trade
name: V #230) <A8> Dimethylol tricyclodecane diacrylate
(manufactured by Kyoeisha Chemical Co., Ltd., Trade name: DCP-A)
<A9> Phenylethylene glycol diacrylate (manufactured by NARD
institute, Ltd.) <A10> m-xylylene diacrylate (manufactured by
NARD institute, Ltd.) <A11>2-phenyl-1,3-propane diol
diacrylate (manufactured by NARD institute, Ltd.)
[0138] (B) Polymerization Initiator
<B1> Lucirin TPO (Manufactured by BASF Japan)
[0139] The compositions of photocurable compositions for imprint
produced using the materials mentioned above are shown in Table 1
shown below. After the preparation, filtration with a 0.2 .mu.m
filter containing ultrahigh molecular weight polyethylene was
performed.
TABLE-US-00001 TABLE 1 Polymerization Polymerizable compound
initiator [part by weight] [part by weight] A1 A2 A3 A4 A5 A6 A7 A8
A9 A10 A11 B1 Example 1 60 -- -- -- -- -- -- -- -- 40 -- 3 Example
2 50 -- -- -- -- -- -- -- -- 50 -- 3 Example 3 75 -- -- -- -- -- --
-- -- 25 -- 3 Example 4 -- -- 60 -- -- -- -- -- -- 40 -- 3 Example
5 -- -- 50 -- -- -- -- -- -- 50 -- 3 Example 6 -- -- -- 60 -- -- --
-- -- 40 -- 3 Example 7 -- -- -- -- 75 25 -- -- -- -- -- 3 Example
8 -- -- -- -- -- -- -- -- 100 -- -- 3 Example 9 -- 50 -- -- -- --
-- -- -- -- 50 3 Example 10 -- -- -- -- -- -- -- -- -- -- 100 3
Comparative 100 -- -- -- -- -- -- -- -- -- -- 3 Example 1
Comparative -- -- 100 -- -- -- -- -- -- -- -- 3 Example 2
Comparative -- -- -- 100 -- -- -- -- -- -- -- 3 Example 3
Comparative -- -- -- -- 100 -- -- -- -- -- -- 3 Example 4
Comparative -- 75 -- -- -- -- -- 25 -- -- -- 3 Example 5
Comparative -- 60 -- -- -- -- -- 40 -- -- -- 3 Example 6
Comparative -- 50 -- -- -- 50 -- -- -- -- -- 3 Example 7
Comparative -- 50 -- -- -- -- 50 -- -- -- -- 3 Example 8
[0140] For the photocurable compositions for imprint shown in Table
1 above, the measurement of viscosity, glass transition
temperature, and dry etching was performed using the following
procedure, and then the coefficient of thermal expansion, the
Ohnishi parameter, and the etching rate were calculated.
(1. Measurement of Viscosity of Photocurable Composition for
Imprint)
[0141] The viscosity of the photocurable compositions for imprint
at 23.degree. C. was measured using a cone-plate type rotation
viscometer RE-85L (manufactured by Toki Sangyo Co., Ltd.).
(2. Production of Photocured Film for Measurement of Glass
Transition Temperature of Photocurable Composition for Imprint)
[0142] 70 .mu.l of a resist was added dropwise and filled into a
100 .mu.m gap between a rotating rod having a bottom surface with a
diameter .PHI. of 8.0 mm and a quartz stage using a rheometer
MCR301 with a UV irradiation option manufactured by Anton Paar. The
normal reaction of the rotating rod was set to zero N in such a
manner that the gap followed curing and shrinkage of the
photocurable composition.
[0143] Next, the rotational vibration cycle of the rotating rod was
set to 5 Hz, and 10 seconds after starting the rotation vibration,
UV light irradiation was started from the quartz stage side. The
exposure time was set to 600 seconds, the exposure wavelength was
fixed to 365 nm, the illuminance was fixed to 1.0 mW/cm.sup.2, and
the temperature was fixed to 23.degree. C.
(3. Measurement of Glass Transition Temperature and Coefficient of
Thermal Expansion of Photocurable Composition for Imprint)
[0144] In the state where the normal reaction of the rotating rod
was set to zero N in such a manner that the gap between the
rotating rod and the quartz stage followed thermal expansion and
thermal shrinkage of the photocurable composition, the photocured
film produced in (2) was measured for the loss tangent tan .delta.
while increasing the temperature from 23.degree. C. to 200.degree.
C. The temperature increase rate was set to 4.degree. C./min. The
temperature at which the tan .delta. reached the maximum was
defined as the glass transition temperature. Further, the
coefficient of thermal expansion of the photocured film was
calculated by the following expression (3).
Film thickness (.mu.m) of photocured film at 120.degree. C./Film
thickness (.mu.m) of photocured film at 23.degree. C.=Coefficient
of thermal expansion (%) (3)
[0145] Herein, the film thickness of the photocured film is a gap
between the rotating rod and the quartz stage.
(4. Calculation of Ohnishi Parameter of Photocurable Composition
for Imprint)
[0146] The Ohnishi parameter of the (A) component of the
photocurable compositions shown in the composition table shown in
Table 1 was calculated using the following expression (2).
OP=n.sub.1OP.sub.1+n.sub.2OP.sub.2+ . . . +n.sub.nOP.sub.n (2)
(5. Production of Photocured Film for Dry Etching of Photocurable
Composition for Imprint)
[0147] 2 .mu.L of the prepared photocurable composition for imprint
was added dropwise onto a silicon wafer on which a 60 nm thick
adhesion promotion layer was formed as an adhesion layer, a 1 mm
thick quartz glass was covered from the top, and then a region (25
mm.times.25 mm) was filled with the photocurable composition for
imprint.
[0148] Next, light emitted from a UV light source having an
ultrahigh pressure mercury lamp from the top of the quartz glass
was made to pass through an interference filter described later,
and then emitted to a coating film for 200 seconds through the
quartz glass. The interference filter used in the light irradiation
was VPF-25C-10-15-31300 (manufactured by SIGMAKOKI Co., LTD.). The
wavelength of the ultraviolet light which was the irradiation light
was a single wavelength light of 313.+-.5 nm and the illuminance
was set to 1 mW/cm.sup.2.
[0149] After the light irradiation, the quartz glass was peeled,
and then a photocured film of the photocurable composition for
imprint having an average film thickness of 3.2 .mu.m was obtained
on the silicon wafer.
(6. Measurement of Etching Rate of Photocured Film for Dry Etching
of Photocurable Composition for Imprint)
[0150] Dry etching was performed for 500 seconds to the photocured
film produced in (5) using a high density plasma etching device
NE-550 manufactured by ULVAC and setting etching gas and the flow
rate thereof to CF.sub.4/CHF.sub.3=50 sccm/50 sccm, and then the
film thickness reduced by the dry etching was measured to calculate
the dry etching rate (nm/s). A lower etching rate indicates that
the dry etching resistance is higher.
[0151] The measurement results above are shown in Table 2 shown
below. The dry etching rate ratio (DE rate ratio) was obtained by
calculating the relative value, when the composition of Comparative
Example 1 was set to 1, in terms of percentage.
TABLE-US-00002 TABLE 2 Coefficient Multifunctional Glass transition
of thermal DE rate monomer ratio temperature expansion ratio
Viscosity [part by weight] (.degree. C.) [%] OP [%] [mP*s] Example
1 40 154 1 3.19 81 9.2 Example 2 50 168 3 3.19 81 9.7 Example 3 25
141 6 3.19 85 8.5 Example 4 40 131 3 3.07 78 11.4 Example 5 50 143
7 3.09 78 11.7 Example 6 40 95 6 2.65 72 10.7 Example 7 25 92 8
2.80 82 15.7 Example 8 100 >200 6 3.20 100 23.0 Example 9 100
>101 -- 2.92 85 6.1 Example 10 100 >200 -- 3.18 90 36.6
Comparative 0 132 18 3.18 100 7.5 Example 1 Comparative 0 109 13
3.00 81 10.6 Example 2 Comparative 0 95 10 2.33 73 9.6 Example 3
Comparative 0 86 10 2.29 83 22.1 Example 4 Comparative 25 55 13
2.83 96 4.2 Example 5 Comparative 40 75 15 2.89 91 6.6 Example 6
Comparative 50 65 19 3.38 105 3.4 Example 7 Comparative 50 45 22
3.15 101 3.8 Example 8
[0152] It can be confirmed from the results shown in Table 2 that
the photocurable compositions for imprint of Examples have a small
thermal expansion.
[0153] Considering the fact that the coefficient of thermal
expansion is less than 10% in Examples 1 to 8, Examples 1 to 8 are
compositions in which the thermal expansion of the resist in the
dry etching was small. Furthermore, considering the fact that the
DE rate ratio is equal to or higher than that of Comparative
Example 1, Examples 1 to 8 are compositions having excellent dry
etching resistance. Since the viscosity is also 50 mPa*s or less,
the filling properties are also excellent. Considering the fact
that Examples 9 and 10 have a DE rate ratio smaller than that of
Comparative Example 1 and having a viscosity of 50 mPa*s or less,
it is considered that Examples 9 and 10 are compositions having a
small thermal expansion similarly to Examples 1 to 8.
[0154] On the other hand, in Comparative Examples 1 to 3, the glass
transition temperature is 90.degree. C. or more but the coefficient
of thermal expansion is 10% or more. This is considered to be
because the proportion of the multifunctional monomer is less than
20% by weight, i.e., only the monofunctional acrylic monomer is
contained, and therefore the crosslink density of Comparative
Examples 1 to 3 is lower than that of the compositions containing
20% by weight or more of the multifunctional acrylic monomer as in
Examples 1 to 8. More specifically, it is considered that thermal
distortion and thermal expansion are likely to occur in dry
etching.
[0155] Comparative Examples 5 to 8 are compositions containing 20%
by weight or more of the multifunctional monomer but the
coefficient of thermal expansion is 10% or more. This is considered
to be because the glass transition temperature is low, and
therefore thermal distortion and thermal expansion are likely to
occur in dry etching similarly to Comparative Examples 1 to 4.
[0156] It can be confirmed that, due to the fact that the
multifunctional monomer is not contained, the composition of
Examples 1 to 8 are photocurable compositions for imprint having
small thermal expansion, excellent dry etching resistance, and also
excellent filling properties.
INDUSTRIAL APPLICABILITY
[0157] As described above, the present invention can provide a
photocurable composition for imprint having small thermal expansion
in dry etching and excellent filling properties in an optical
imprint method. Moreover, the present invention can also provide a
method for producing the photocurable composition for imprint, a
method for producing a film, a method for producing an optical
component, a method for producing a circuit board, and a method for
producing an electronic component.
[0158] The present invention can provide a photocurable composition
for imprint having small thermal expansion in dry etching and
excellent filling properties in an optical imprint method.
Moreover, the present invention can also provide a method for
producing a film using the photocurable composition for imprint, a
method for producing an optical component using the photocurable
composition for imprint, a method for producing a circuit board
using the photocurable composition for imprint, and a method for
producing an electronic component using the photocurable
composition for imprint.
[0159] While the present invention has been described with
reference to exemplary embodiments, it is to be understood that the
invention is not limited to the disclosed exemplary embodiments.
The scope of the following claims is to be accorded the broadest
interpretation so as to encompass all such modifications and
equivalent structures and functions.
* * * * *