U.S. patent application number 13/195410 was filed with the patent office on 2011-11-24 for imprint method using a mold and process for producing structure using an imprint apparatus.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Junichi Seki, Nobuhito Suehira.
Application Number | 20110284499 13/195410 |
Document ID | / |
Family ID | 37654877 |
Filed Date | 2011-11-24 |
United States Patent
Application |
20110284499 |
Kind Code |
A1 |
Suehira; Nobuhito ; et
al. |
November 24, 2011 |
IMPRINT METHOD USING A MOLD AND PROCESS FOR PRODUCING STRUCTURE
USING AN IMPRINT APPARATUS
Abstract
In order to alleviate or suppress curing of a photocurable resin
material in an area in which the curing of the photocurable resin
material is not intended, exposure of the photocurable resin
material to light is suppressed through a non-pattern portion at
which a light-blocking member is provided by means of a mold having
an imprint pattern portion and the non-pattern portion or is
suppressed by disposing a light-blocking member so as not to
irradiate the photocurable resin material with light not via the
mold.
Inventors: |
Suehira; Nobuhito;
(Kawasaki-shi, JP) ; Seki; Junichi; (Yokohama-shi,
JP) |
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
37654877 |
Appl. No.: |
13/195410 |
Filed: |
August 1, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11468870 |
Aug 31, 2006 |
8011916 |
|
|
13195410 |
|
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Current U.S.
Class: |
216/41 ;
264/496 |
Current CPC
Class: |
B29C 2035/0827 20130101;
B82Y 10/00 20130101; B29C 2059/023 20130101; G03F 7/0002 20130101;
B29C 59/022 20130101; Y10T 428/24802 20150115; B29C 35/0894
20130101; B82Y 40/00 20130101 |
Class at
Publication: |
216/41 ;
264/496 |
International
Class: |
B29C 35/08 20060101
B29C035/08; B44C 1/22 20060101 B44C001/22 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 6, 2005 |
JP |
2005-257431 |
Claims
1. An imprint method, comprising: providing a substrate having a
first a photocurable resin material and a mold having an imprint
pattern so as to be opposed to each other; changing, in a first
processing area on the substrate, a shape of the first photocurable
resin material into a shape such that the imprint pattern of the
mold is inverted; curing the first photocurable resin material in
the first processing area by exposure to exposure light; separating
the cured first photocurable resin material and the mold;
providing, in a second processing area on the substrate which does
not overlap with the first processing area, a second photocurable
resin material on the substrate and the mold so as to be opposed to
each other; changing a shape of the second photocurable resin
material into the shape such that the imprint pattern of the mold
is inverted; curing the second photocurable resin material in the
second processing area by the exposure to exposure light while
light-blocking a side surface of the mold with a light-blocking
member provided on the mold so that the cured first photocurable
resin material in the first processing area is prevented from being
exposed again to the exposure light which passes through an inside
of the mold and leaks out from the side surface of the mold; and
separating the cured second photocurable resin material and the
mold.
2. The method according to claim 1, wherein when the first
photocurable resin material in the first processing area is changed
in shape into the shape such that the imprint pattern of the mold
is inverted, and then is cured, the first photocurable resin
material in the first processing area is cured by the exposure to
the exposure light while preventing the first photocurable resin
material, flowing to an outside of the first processing area, from
being cured.
3. The method according to claim 1, wherein while preventing the
second processing area from being exposed to the exposure light,
the first photocurable resin material in the first processing area
is changed in shape into the shape such that the imprint pattern of
the mold is inverted, and then is cured.
4. The method according to claim 1, wherein the first and second
photocurable resin materials are applied onto the substrate in the
first and second processing areas, respectively.
5. The method according to claim 1, wherein the first and second
photocurable resin materials are collectively applied onto a
surface of the substrate including the first and second processing
areas.
6. The method according to claim 1, wherein the mold has three
surfaces including a processing surface on which the imprint
pattern is formed, a back surface opposite from the processing
surface, and a surface which is provided between the processing
surface and the back surface and in an area other than an area in
which the processing surface is formed, and wherein the three
surfaces provide a projection structure.
7. The method according to claim 1, wherein the imprint method is
repeated to provide, on the substrate, a plurality of transfer
areas onto which the imprint pattern of the mold is transferred,
and then an uncured resin material which is dispersed and remains
at a plurality of portions each between adjacent transfer areas of
the plurality of transfer areas is removed.
8. A process for producing a structure, the process comprising:
applying a photocurable resin material as a member to be processed
onto a substrate; and forming a resin layer having an imprint
pattern by curing the photocurable resin material using light with
an imprint apparatus comprising: a mold comprising a processing
side having an imprint pattern, a back side opposite from the
processing side, and a non-pattern portion at which the imprint
pattern is not provided; and an exposure light source, wherein the
mold further comprises a light-blocking member disposed at the
non-pattern portion so as to decrease an amount of light with which
the member to be processed is irradiated through the non-pattern
portion.
9. A process for producing a structure, the process comprising:
applying a photocurable resin material as a member to be processed
onto a substrate; forming a resin layer having an imprint pattern
by curing the photocurable resin material using light with an
imprint apparatus comprising: a mold comprising a processing side
having an imprint pattern, a back side opposite from the processing
side, and a non-pattern portion at which the imprint pattern is not
provided; and an exposure light source, wherein the mold further
comprises a light-blocking member disposed at the non-pattern
portion so as to decrease an amount of light with which the member
to be processed is irradiated through the non-pattern portion;
etching the substrate by using the resin layer having the imprint
pattern as a mask; and removing the resin layer remaining on the
substrate after the etching.
10. The process according to claim 9, wherein an uncured resin
material is removed before the etching.
11. A process for producing a structure, the process comprising:
preparing an imprint apparatus comprising: a mold comprising a
processing side having an imprint pattern, a back side opposite
from the processing side, and a non-pattern portion at which the
imprint pattern is not provided; and an exposure light source,
wherein the mold further comprises a light-blocking member disposed
at the non-pattern portion so as to decrease an amount of light
with which the member to be processed is irradiated through the
non-pattern portion; and curing a specific portion of photocurable
resin material located in a processing area to effect transfer of a
pattern formed on a processing side of a mold.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of application Ser. No.
11/468,870, filed Aug. 31, 2006, which claims priority from
Japanese Patent Application No. 257431/2005, filed Sep. 6, 2005.
Both prior applications are hereby incorporated herein by
reference.
FIELD OF THE INVENTION AND RELATED ART
[0002] The present invention relates to a mold having a shape that
is to be transferred onto a work or workpiece (member to be
processed). The present invention also relates to an imprint
apparatus and a process for producing a structure.
[0003] In recent years, as described in Stephan Y. Chou et al.,
Appl. Phys. Lett., Vol. 67, Issue 21, pp. 3114-3116 (1995), fine
processing technology for transferring a minute structure on a mold
onto a work comprising a semiconductor, glass, resin, metal, etc.,
has been developed and has received attention.
[0004] Because this technology provides a resolution on the order
of several nanometers, it is called nanoimprint (nanoimprinting) or
nanoembossing. Although the nanoimprint has the above-described
resolution, it is also suitably used for processing members having
minimum processing widths of not more than 1 mm, not more than 1
.mu.m, and not more than 100 nm. Further, according to the
nanoimprint, it is possible to simultaneously process an area
having a processing width of not more than 100 nm and an area
having a processing width of not more than 1 .mu.m with respect to
a work. In other words, the nanoimprint has such an advantage,
compared with a processing of a work by photolithography, that
processing of the work can be performed in a plurality of areas
having processing widths that differ by not less than one digit,
more preferably not less than three digits, at the same time.
[0005] This technology can be employed not only in the production
of a semiconductor device, but also in batch processing of a
three-dimensional structure at a wafer level. For this reason, the
nanoimprint has been expected to be applied to a wide variety of
fields, e.g., production technologies for an optical device, such
as a photonic crystal, a micro total analysis system (.mu.-TAS), a
biochip, etc.
[0006] The case where a semiconductor device as a structure is
produced through a photoimprint method will be described.
[0007] First, a layer of photocurable resin material is formed on a
substrate (e.g., a semiconductor wafer).
[0008] Next, a mold (or template) on which a desired imprint
structure is formed is brought into contact with the resin layer.
In this state, the resin layer is irradiated with ultraviolet light
to cure the photocurable resin material.
[0009] As a result, an imprint pattern of the above-described
imprint structure on the resin layer is inverted. This is referred
to as a transfer of an imprint structure.
[0010] Further, by using the resin layer as an etching mask, e.g.,
etching of the substrate surface is effected to transfer the
imprint structure onto the substrate.
[0011] As described above, different from a conventional processing
method using a light exposure apparatus, the imprint (method)
permits transfer of the minute structure provided on the mold onto
the work.
[0012] During the processing by the imprint, the photocurable resin
material flowing from the mold is adhered to the mold on its
lateral side. The photocurable resin material adhered to the
lateral side of the mold is cured, together with the photocurable
resin material located at a portion at which the imprint structure
(imprint pattern) is to be formed, by light passing through the
outside of the mold during light exposure. By such curing, a large
force acts on the mold or the work during a release of the mold
from the work to damage the mold or the work.
[0013] Further, in some cases, the photocurable resin material
outside the portion at which the imprint pattern is to be formed is
excessively exposed to light passing through the outside of the
imprint pattern portion formed in the mold during light exposure
and deforms into an undesirable shape. Particularly, in such a case
where a resin material is applied onto a substrate by spin coating
and processing of a work is repeated by a step-and-repeat method,
the portion at which the imprint pattern is to be formed is exposed
to light before the processing.
SUMMARY OF THE INVENTION
[0014] An object of the present invention is to provide a mold
capable of alleviating or suppressing curing of a photocurable
resin material in an area in which the curing of the photocurable
resin material is not intended.
[0015] Another object of the present invention is to provide a
pressure processing apparatus using the mold and a production
process of a structure using the pressure processing apparatus.
[0016] According to an aspect of the present invention, there is
provided a mold for use in an imprint apparatus in which a
photocurable member to be processed is processed by irradiation,
through a mold having an imprint pattern, with light for curing the
member to be processed in a state in which the mold is brought into
contact with the member to be processed, the mold comprising:
[0017] a processing side having an imprint pattern;
[0018] a back side opposite from the processing side; and
[0019] a non-pattern portion at which the imprint pattern is not
provided;
[0020] wherein the mold further comprises a light-blocking member,
disposed at the non-pattern portion, for decreasing an amount of
light with which the member to be processed is irradiated through
the non-pattern portion.
[0021] According to another aspect of the present invention, there
is provided an imprint apparatus for processing a photocurable
member by irradiation, through a mold having an imprint pattern,
with light for curing the member to be processed in a state in
which the mold is brought into contact with the member to be
processed, the apparatus comprising:
[0022] a mold comprising a processing side having an imprint
pattern, a back side opposite from the processing side, and a
non-pattern portion at which the imprint pattern is not provided;
and
[0023] an exposure light source;
[0024] wherein the mold further comprises a light-blocking member
disposed at the non-pattern portion so as to decrease an amount of
light with which the member to be processed is irradiated through
the non-pattern portion.
[0025] According to another aspect of the present invention, there
is provided an imprint apparatus for processing a photocurable
member to be processed by irradiation, through a mold having an
imprint pattern, with light for curing the member to be processed
in a state in which the mold is brought into contact with the
member to be processed, the apparatus comprising:
[0026] a light source for generating the light; and
[0027] a mold holding portion for holding the mold;
[0028] wherein the apparatus further comprises a light-blocking
member for decreasing an amount of light with which the member to
be processed is irradiated from the light source not through the
mold.
[0029] According to another aspect of the present invention, there
is provided a process for producing a structure, comprising:
[0030] applying a photocurable resin material as a member to be
processed onto a substrate; and
[0031] forming a resin layer having an imprint pattern by curing
the photocurable resin material with the imprint apparatus
described above.
[0032] According to a further aspect of the present invention,
there is provided a process for producing a structure,
comprising:
[0033] applying a photocurable resin material as a member to be
processed onto a substrate;
[0034] forming a resin layer having an imprint pattern by curing
the photocurable resin material with the imprint apparatus
described above;
[0035] etching the substrate by using the resin layer having the
imprint pattern as a mask; and
[0036] removing the resin layer remaining on the substrate after
the etching.
[0037] According to a still further aspect of the present
invention, there is provided a process for producing a structure,
comprising:
[0038] preparing the imprint apparatus described above; and
[0039] curing a specific portion of photocurable resin material
located in a processing area to effect transfer of a pattern formed
on a processing side of a mold.
[0040] Using the above-described light-blocking member, according
to the present invention, it is possible to alleviate or suppress
the curing of the photocurable resin material in an area other than
a portion at which the imprint pattern is to be formed by
processing.
[0041] These and other objects, features and advantages of the
present invention will become more apparent upon a consideration of
the following description of the preferred embodiments of the
present invention taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIGS. 1A to 1H are schematic views each showing a
constitution of a mold according to an embodiment of the present
invention.
[0043] FIGS. 2A and 2B are schematic views each showing a
preparation method of a mold provided with a light-blocking
member.
[0044] FIGS. 3A and 3B are schematic views each showing an example
of a constitution of an imprint apparatus according to an
embodiment of the present invention.
[0045] FIG. 4A is a top view for illustrating a procedure for
processing a work in an embodiment of the present invention, and
FIG. 4B is a sectional view taken along the A-A' line shown in FIG.
4A.
[0046] FIG. 5A is a top view showing a work after processing in an
embodiment of the present invention, and FIG. 5B is a sectional
view taken along the A-A' line shown in FIG. 5A.
[0047] FIGS. 6A to 6D are schematic views for illustrating an
occurrence of deficiency in the case where a light-blocking member
is not provided.
[0048] FIGS. 7A to 7D are schematic views each showing a
constitution of a projection-type mold according to another
embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] In an embodiment of the present invention, a mold having an
imprint pattern can be constituted in the following manner.
[0050] FIG. 1A shows a cross-section of the mold in this
embodiment.
[0051] Referring to FIG. 1A, the mold includes a transparent member
101, a processing side 102, a light-blocking member 103, an imprint
pattern portion 104, and a non-pattern portion 105. Incidentally,
broken lines between the imprint pattern portion 104 and the
non-pattern portion 105 in the figure are depicted for indicating a
boundary therebetween for convenience of an explanation.
[0052] The mold has a first surface 106 and a second surface 107.
The first surface 106 constitutes the processing side 102 having an
imprint pattern and the second surface 107 constitutes a side
identical in location to the processing side 102 having the imprint
pattern at the imprint pattern portion 104.
[0053] As shown in FIG. 1A, in the case of providing the
non-pattern portion 105 so as to be adjacent to the imprint pattern
portion 104, the light-blocking member 103 is provided at least at
any one of the side 107 identical in location to the processing
side 106 having the imprint pattern at the non-pattern portion 105,
a side identical in location to back side at the non-pattern
portion 105, and a lateral side of the mold at the non-pattern
portion.
[0054] In the case where the non-pattern portion 105 is not
provided to the mold, as described below, the light-blocking member
may be disposed at the lateral side of the mold. In this case, the
mold itself can be regarded as the non-pattern portion.
[0055] The light-blocking member used in the present invention may
include not only the one, which completely blocks light capable of
curing a photocurable resin material constituting at least a part
of a work, but also the one, which does not completely block the
light. In the latter case, the light-blocking member may only be
required to provide a necessary difference in the degree of curing
of the photocurable resin material between an area in which the
light is not blocked and an area in which the light is blocked.
[0056] In another embodiment of the present invention, as described
later, it is preferable that an imprint apparatus includes a
light-blocking member (light-blocking means) for blocking light
with which a member to be processed is irradiated from an exposure
light source not through the mold.
[0057] According to this embodiment of the present invention, it is
possible to alleviate or suppress the curing of the photocurable
resin material in the neighborhood of the lateral side of the mold.
Further, the mold may be constituted by providing the
light-blocking member so that the photocurable resin material close
to the lateral side of the mold during processing is not cured or
is less cured than that located in the imprint pattern portion.
[0058] In the case where the processing is performed by a
step-and-repeat method, only a photocurable resin material (uncured
resin material) in a specific processing area of a work (member to
be processed) is exposed, so that an uncured resin material in an
area to be subsequently processed is prevented from being exposed
to light.
[0059] The step-and-process method may, e.g., be the following
method.
[0060] First, a work is prepared by coating an entire surface of a
substrate with a photocurable resin material. Next, a part of the
surface of the work is irradiated with light in a state in which
the mold is brought into contact with the work, whereby the
photocurable resin material only at the part of the surface of the
substrate is cured. Thereafter, the mold is removed from the work.
These steps are repetitively performed with respect to another part
of the surface of the substrate while moving the work in an
in-plane direction of the work.
[0061] Herein, the photocurable resin material after being cured by
light irradiation is no longer the photocurable resin material, but
is inclusively referred to, sometimes, as the photocurable resin
material for convenience.
[0062] Another embodiment of the present invention will be
described below. As described above, the object of the present
invention is to suppress or alleviate the curing of the
photocurable resin material in an area in which the curing of the
photocurable resin material is not intended. Thus, the present
invention is not limited to the following embodiment.
[0063] Here, the area in which the curing of the photocurable resin
material is not intended means, e.g., the following areas in the
case where a mold has an imprint pattern portion and a non-pattern
portion adjacent to the imprint pattern portion. More specifically,
examples of such areas may include an area of the photocurable
resin material at the non-pattern portion, an area of the
photocurable resin material in the neighborhood of an outer
periphery portion (lateral side) of the mold, and an area of the
photocurable resin material located at an outer lateral side of the
mold during contact with the photocurable resin material.
[0064] Embodiments of the Mold
[0065] With reference to FIGS. 1B to 1H, constitutions of molds
according to several embodiments of the present invention will be
described.
[0066] In these figures, the same members or portions identical to
those in FIG. 1A are represented by identical reference
numerals.
[0067] FIG. 1B shows a constitution in which the light-blocking
member 103 is disposed only at a lower portion of the lateral side
of the mold.
[0068] FIG. 1C shows a constitution in which the light-blocking
member protrudes downward from the lateral side of the mold.
[0069] In the above-described constitution, a light-blocking effect
is further enhanced in the case of FIG. 1A, i.e., in the case where
a level of the lateral side of the mold does not reach the same
level as a (lower) surface of the projection constituting the
imprint pattern at the imprint pattern portion 104. Further, in the
case of FIG. 1C, a length of the protruded portion of the
light-blocking member from the lateral side of the mold may
desirably be not more than a distance between the surface of the
projection of the imprint pattern portion 104 and the surface 107
identical in location to the processing side of the mold at the
non-pattern portion 105.
[0070] FIG. 1D shows a constitution in which a reinforcing member
108 for reinforcing the light-blocking member 103 is provided. For
example, in some cases, the light-blocking member 103 has a
thickness of approximately 50 nm. In this case, when the
light-blocking member does not have a sufficient strength, it is
possible to prevent a breakage at the lower portion of the
light-blocking member 103 by reinforcing the lower portion with the
reinforcing member 108.
[0071] FIG. 1E shows a constitution in which the light-blocking
member 103 is disposed at a lower side (surface) 107. In this case,
the light-blocking member 103 may desirably have a thickness of not
more than the distance between the surface of the projection of the
imprint pattern portion 104 and the surface 107 identical in
location to the processing side of the mold.
[0072] FIG. 1F shows a constitution in which the light-blocking
member 103 is disposed on a back side (upper side) at the
non-pattern portion 105.
[0073] FIG. 1G shows a constitution in which the light-blocking
member 103 is disposed at the lower side (surface) 107 in addition
to the lateral side of the mold. In this case, at the lower side
107, the light-blocking member 103 may desirably have a thickness
of not more than the distance between the surface of the projection
of the imprint pattern portion 104 and the surface 107 identical in
location to the processing side of the mold.
[0074] FIG. 1H shows a constitution in which the light-blocking
member 103 is disposed on the back side (upper side) at the
non-pattern portion 105 in addition to the lateral side of the
mold.
[0075] Further, another embodiment of the present invention will be
described with reference to FIGS. 7A to 7D.
[0076] Different from the molds shown in FIGS. 1A to 1H, those
shown in FIGS. 7A to 7D are of such a projection type wherein a
third side is provided between the processing side and the back
side.
[0077] Referring to FIG. 7A, the mold includes a transparent member
701, a light-blocking member 702, a third side 703, a second side
704, a third side 705, and a back side 706. In FIG. 7B, the
light-blocking member 702 is disposed on the lateral side located
between the first side 703 and the third side 705 and is disposed
on the third side 705. In FIG. 7C, the light-blocking member 702 is
disposed on the third side 705. In FIG. 7D, the light-blocking
member 702 is disposed on the lateral side located between the
first side 703 and the third side 705, on the third side 705, and
on the lateral side located between the third side 705 and the back
side 706.
[0078] Next, a preparation method of the above-described mold will
be described with reference to FIGS. 2A and 2B, each showing steps
for providing a light-blocking member 203 on a lateral side of a
substrate 201 formed of a transparent member for a mold. On the
substrate 201, a resist 202 is to be disposed.
[0079] Herein, the mold substrate 201 has a front side as a
processing side to be subjected to processing, a back side opposite
from the front side (processing side), and a lateral side
connecting the front side and the back side.
[0080] First, the preparation method of the mold by vapor
deposition will be described with reference to FIG. 2A showing
steps a-1 to a-5.
[0081] In step a-1, the substrate 201 is prepared. The substrate
201 may be formed of a light-transmissive substance including
heat-resistant glass, such as quartz glass or Pyrex (registered
trademark), and sapphire.
[0082] Next, in step a-2, a negative resist 202 is applied onto the
processing side of the substrate 201 by a spin coater or the like
and is irradiated with light to be modified so that it is not
readily dissolved in a developing solution.
[0083] Next, in step a-3, a negative resist 202 is applied onto the
back side of the substrate 201 by a spin coater or the like and is
irradiated with light to be modified so that it is not readily
dissolved in a developing solution.
[0084] When the resist is adhered to the lateral side of the
substrate, it can be removed by, e.g., polishing. Further, in steps
a-2 and a-3, the coating may also be performed after a film-like
mask is provided on the lateral side of the substrate so that the
resist is not adhered to the lateral side of the substrate.
[0085] Next, in step a-4, a light-blocking member 203 is provided
on the lateral side of the substrate. The light-blocking member 203
is vapor-deposited in a layer (film) of a metal, such as Cr, on the
lateral side of the substrate by sputtering, chemical vapor
deposition (CVD), vacuum vapor deposition, ion plating, etc. The
resultant metal film is only required to sufficiently block
ultraviolet (UV) light and may desirably have a thickness of not
more than 50 nm. Further, the light-blocking member 203 may be
formed of organic materials of an acrylic type, a urethane type, a
polycarbonate type, etc., or of inorganic materials of a carbon
type, etc. These materials may further contain other materials,
such as a colorant.
[0086] Next in step a-5, the resist 202 is removed from the
substrate 201 to complete the substrate 201 with the light-blocking
member 203.
[0087] Then, the surface of the substrate 201 is processed by a
method described below to form an imprint pattern (not shown).
[0088] Next, the preparation method of the mold by polishing will
be described with reference to FIG. 2B showing steps b-1 to
b-4.
[0089] First, in step b-1, a substrate 201 is prepared.
[0090] Next, in step b-2, a light-blocking member 203 is disposed
on the substrate 201 by dipping the substrate 201 in or coating the
substrate 201 with a solution containing a material constituting
the light-blocking member 203 or its precursor. Then, the
light-blocking member 203 is fixed on the substrate 201 by removing
the solvent. In the case where the light-blocking member 203 is
provided only at a part of lateral side of the substrate 201,
dipping of the substrate 201 may be effected to a necessary
depth.
[0091] The light-blocking member 203 may be formed of the same
material as those described with reference to FIG. 2A.
[0092] Next, in step b-3, the light-blocking member 203 formed on a
back side of the substrate 201 is removed by polishing the back
side of the substrate 201 through chemical mechanical polishing
(CMP), etc.
[0093] Next, in step b-4, a front side of the substrate 201 is
polished to complete the substrate 201 provided with the
light-blocking member 203 on the lateral side of the substrate
201.
[0094] Incidentally, the light-blocking member 203 is not limited
to those formed by the above-described liquid phase deposition or
vapor phase deposition, but may also be formed by adhering a
film-like light-blocking substance or a plate-like light-blocking
substance to the substrate 201.
[0095] Further, it is also possible to provide a mask in advance at
a position where the light-blocking member 203 is not intended to
be formed.
[0096] Further, the steps b-2 and b-3 may also be repeated in
several cycles.
[0097] It is also possible to use the methods shown in FIG. 2A and
FIG. 2B in combination.
[0098] The processing side of the thus prepared substrate having
the light-blocking member is subjected to formation of the imprint
pattern through an ordinary patterning method, such as
photolithography, electron beam lithography, focused ion beam (FIB)
processing, or X-ray lithography, thus completing the mold.
[0099] Incidentally, the light-blocking member may also be formed
after the imprint pattern is formed on the processing side of the
substrate.
[0100] Effect of the Imprint Apparatus
[0101] A constitutional example of an imprint apparatus according
to an embodiment of the present invention will be described.
[0102] FIG. 3A shows the constitutional example of the imprint
apparatus in this embodiment.
[0103] Referring to FIG. 3A, the imprint apparatus may include a
mold 301, a mold holding portion 302, a body tube 303, a
photocurable resin material 304, a substrate 305, a work holding
portion 306, a work pressing mechanism 307, an XY moving mechanism
308, an exposure light source 309, a light-blocking member 310,
exposure light 310, and an imprint control mechanism 312.
[0104] The imprint apparatus in this embodiment is principally
constituted by the mold holding portion 302, the work holding
portion 306, the work pressing mechanism 307, the XY moving
mechanism 308, the exposure light source 309, and the imprint
control mechanism 312. On the work holding portion 306, a work
(member to be processed) constituted by the substrate 305 coated
with the photocurable resin material 304 by a coating method, such
as spin coating or slit coating, is disposed. The imprint apparatus
further includes a position detection apparatus for effecting the
alignment, which is not shown and is omitted from the
explanation.
[0105] The mold holding portion 302 effects chucking of the mold
301 by a vacuum chucking method or the like. The work is movable to
a desired position by the XY moving mechanism 308, and the work
pressing mechanism 307 can effect a height adjustment (level
control) and pressing of the work. The exposure light 311 from the
exposure light source 309 passes through the body tube 303 and
reaches the mold 301. The light 311 is restricted so as not to
reach the outside of the mold 301 by limiting light fluxes with a
lens or a diaphragm. The position movement, pressing, and light
exposure of the work are controlled by the imprint control
mechanism 312.
[0106] The mold 301 shown in FIG. 3A in this embodiment is
constituted by a transparent member and is provided with a
light-blocking member 103 on an entire lateral side (non-pattern
portion) of the mold 301. As a result, it is possible to prevent
the light 311 from reaching the outside of the mold 301 through the
mold 301, so that it is possible to prevent the photocurable resin
material 304 from being cured at a portion outside the mold 301 and
being excessively exposed to light at the portion outside the mold
301. Particularly, an in-plane area of the work, which has not been
subjected to processing, cannot be exposed to light, so that it is
possible to prevent a phenomenon in which the photocurable resin
material 304 in the in-plane area (before processing) is cured so
as not to permit a transfer of the imprint pattern of the mold
301.
[0107] FIG. 3B shows another example of the body tube 303, which is
constituted in the following manner.
[0108] As shown in FIG. 3B, the light-blocking member 310 is
provided at necessary portions of the body tube 303 and the mold
holding portion 302, so that the exposure light reaching a portion
other than a necessary portion for exposure not through the mold,
i.e., the so-called stray light is completely blocked. By employing
such a constitution, it is possible to prepare the body tube 303
and the mold holding portion 302 with a light-transmissive
material. Further, it is not necessary to limit an irradiation
range of the light from the light source 309 by the lens or
diaphragm.
[0109] The exposure light emitted from the light source 309 passes
through the mold to reach the back side of the mold. Even when
light fluxes of the exposure light from the light source travel in
a divergent manner, in parallel lines, or in a convergent manner,
they are reflected or scattered by various members in some cases
depending on a constitution of the imprint apparatus. Further,
there is also a possibility that the exposure light leaks from a
gap between the members.
[0110] In these cases, by adopting the constitution as shown in
FIG. 3B, it is possible to further enhance the light-blocking
effect. More specifically, the light-blocking member 310 is
provided at necessary portions of the body tube 303 and the mold
holding portion 302, i.e., on the lateral side of the body tube 303
and the lateral side and the peripheral lower side of the mold
holding portion 302, thus completely blocking the exposure light
from reaching portions other than the necessary portions. By using
the light-blocking member 310 and the light-blocking member 103 for
the mold 301 in combination, an area to be exposed to light of the
work is restricted to an area identical to the lower side
(processing side) of the mold at the imprint pattern portion.
[0111] Embodiment of the Production Process of the Structure
[0112] A process for producing a structure according to an
embodiment of the present invention will be described.
[0113] FIGS. 4A and 4B are schematic views for illustrating a
procedure for processing a work, wherein FIG. 4A is a top view and
FIG. 4B is a sectional view taken along the A-A' line shown in FIG.
4A.
[0114] Referring to FIGS. 4A and 4B, reference numeral 401
represents a work, 407 represents a mold, 408 represents a
substrate, 409 represents a photocurable resin material, and 410
represent a cured resin material after an imprint pattern is
transferred onto it. On an entire lateral side of the mold 407, a
light-blocking member 103 is provided. Further, reference numeral
405 represents a processing path, which is the shortest path for
processing. In the work 401, numbers 1 to 21 each represents an
area per one shot of processing and the processing of work is
performed on the order of an increasing number. Further, reference
numeral 402 indicated by a broken line shows nine areas, No. 1 to
No. 9, which have already been processed. Reference numeral 403
indicated by a bold solid line shows a current processing area No.
10. Reference numeral 404 indicated by a solid line shows even
unprocessed areas, No. 11 to No. 21. Further, reference numeral 406
represents an unexposed area, in the neighborhood of an edge of the
wafer (work), which is not exposed to light even after the
processing of the work is completed.
[0115] The processing of the work is effected by repetitively
performing the XY movement of the work, contacting the mold with
the work, exposing the work to light, and removing the mold.
[0116] For example, the processing of the work at position No. 10
will be described.
[0117] First, the work moved to position No. 10 is brought into
contact with the mold or the mold is brought into contact with the
work. As a result, the photocurable resin material that cannot be
accommodated between the mold and the work flows from the
processing side to the outside of the processing side.
[0118] Then, only the photocurable resin material within the
processing area No. 10 is cured by light exposure. In this case, by
using the above-described light-blocking members, it is possible to
block the light passing through the processing side of the mold and
the non-pattern portion of the mold during light irradiation from
the light source. For this reason, the photocurable resin material
flowing from the processing side to the outside of the processing
side is not exposed to light and is, thus, not cured. As a result,
it is possible to prevent the mold and the work from being damaged
during the removal of the mold from the water. Further, it is
possible to block the light that travels toward the outside of the
processing area No. 10, so that areas Nos. 1 to 9 are not
excessively exposed to light, and light exposure in unprocessed
areas Nos. 11 to 21 can be prevented.
[0119] Further, it is possible to decrease a processing margin in
the processing area. Accordingly, it is also possible to set a
distance of movement of the mold during the processing so as to be
equal to the length of one side of the mold. As a result, it is
possible to effectively use a planar area of the substrate.
[0120] In the case where the resin material itself, which has been
cured and formed in an imprint pattern, is used as a structure, the
production process of the structure is completed. Further, in the
case where the production process of the structure is used in
production of a semiconductor device such as LSI, by using the
resin material itself, which has been cured and formed in the
imprint pattern, as an etching mask, the surface of the underlying
substrate is subjected to etching so as to form a recess, such as
grooves corresponding to the above-described imprint pattern.
[0121] FIGS. 5A and 5B show the work after the processing is
completed. FIG. 5A is a top view of the work and FIG. 5B is a
sectional view of the work taken along the A-A' line shown in FIG.
5A.
[0122] In these figures, reference numeral 501 represents a work,
502 represents an area after the processing, 503 represents an
unexposed area, 504 represents a substrate, 505 represents a cured
resin material after a pattern is transferred onto the cured resin
material, and 506 represents an uncured resin material, which flows
from the processing area to the outside of the processing area
during the processing and is located in the neighborhood of the
boundary of the processing area without being exposed to light.
[0123] The uncured resin materials in the neighborhood of the
boundary of the processing area and in the unexposed area adversely
affect subsequent steps in some cases. For example, the pattern
portion is covered with the uncured resin material, and when the
etching is performed in such a state, an etching rate is changed
and a desired pattern is not obtained. In order to obviate such an
adverse affect, the uncured resin materials can be blown off,
removed by washing, or cured by exposure to light.
[0124] Incidentally, as the coating method of the photocurable
resin material, it is possible to use an ink jet method in which
the photocurable resin material is coated on the substrate for each
processing area. In the case where the processing is effected by
using the ink jet method, a cycle of application of the resin
material onto a processing area, XY movement of the work, contact
of the mold with the work, light exposure to the work, and removal
of the mold from the work is repeated. In this case, on the
substrate, there are three areas including an area in which the
processing is effected so as to transfer the pattern onto the resin
material, an area in which the processing has not yet been effected
and the substrate provided with no resin material is exposed, and
an area being processed. Even in such a case, by using the
light-blocking members in this embodiment, it is possible to
prevent irradiation of the area, after the processing is completed,
with the exposure light. As a result, the resin material in the
processed area can be prevented from being excessively exposed to
light.
[0125] Here, in the case where the light-blocking member is not
provided to the mold or the imprint apparatus, an occurrence of a
defect will be described more specifically.
[0126] A constitutional example in the case where the
light-blocking member is not provided to the mold or the imprint
apparatus is shown in each of FIGS. 6A to 6D.
[0127] In these figures, reference numeral 601 represents a mold,
602 represents exposure light, 603 represents a substrate, 604
represents a resin material, 605 represents a resin material
flowing from the mold 601 to the outside of the mold 601, 606
represents a processing area in which the mold 601 has been
successfully removed from the substrate 603. The processing area
606 includes a mold area 607 and margin area 608. The margin area
608 is a minimum area, located outside the mold 601, in which the
resin material is cured by exposure to light.
[0128] FIG. 6A shows a light exposure process. The exposure light
is radially diverged from the light source and passes through the
inside of the mold, so that the outside of the mold is irradiated
with the exposure light. As a result, the resin material is exposed
to light in not only the mold area, but also in the margin
area.
[0129] The defect in such a constitution will be described
below.
[0130] The pattern has a depth (thickness) on the order of
approximately 100 nm, but the thickness of the resin material
flowing outside the mold sometimes amounts to several millimeters.
When such a resin material is cured, it is possible for a part or
all of the resin material on the substrate to be removed due to the
thin layer of resin material on the substrate. Further, when the
amount of the exposure light is small and, thus, the resin material
is not sufficiently cured, the resin material is attached to the
mold and can be dropped from the mold during the movement of the
mold to result in a defect.
[0131] A specific example the defect will be described with
reference to FIGS. 6B to 6D.
[0132] FIG. 6B shows an example in which a small resin material
piece 609 is separated from a resin material 610 and attached to
the mold. Such a resin material piece 609 is sometimes dropped from
the mold onto the work during the processing. When the dropped
resin material piece 609 is sandwiched between the work and the
mold and deposited on the processing side of the mold, from then
on, the processing apparatus has a defect.
[0133] FIG. 6C shows an example in which a large resin material
piece 611 is removed from the substrate 603, so that a surface 612
of the substrate 603 is exposed. In this case, the resin material
piece 611 is cured and a defect occurs in subsequent areas.
[0134] FIG. 6D shows an example in which a resin material portion
613 is partially raised from the substrate 603 in an area. When
this area is a margin area, the resin material portion 613 is a
limitative defect.
[0135] In the cases shown in FIGS. 6B to 6D, according to the
embodiments of the present invention, it is possible to prevent the
curing of the resin material located at a peripheral portion of the
processing area of the mold, thus preventing an occurrence of a
defect, etc.
[0136] While the invention has been described with reference to the
structures disclosed herein, it is not confined to the details set
forth above, and this application is intended to cover such
modifications or changes as may come within the purpose of the
improvements or the scope of the following claims.
* * * * *