U.S. patent application number 17/518929 was filed with the patent office on 2022-02-24 for template, template manufacturing method, and semiconductor device manufacturing method.
The applicant listed for this patent is TOSHIBA MEMORY CORPORATION. Invention is credited to Hirokazu KATO, Kei KOBAYASHI, Anupam MITRA, Seiji MORITA.
Application Number | 20220055254 17/518929 |
Document ID | / |
Family ID | |
Filed Date | 2022-02-24 |
United States Patent
Application |
20220055254 |
Kind Code |
A1 |
KOBAYASHI; Kei ; et
al. |
February 24, 2022 |
TEMPLATE, TEMPLATE MANUFACTURING METHOD, AND SEMICONDUCTOR DEVICE
MANUFACTURING METHOD
Abstract
According to one embodiment, a template for imprint patterning
processes comprises a template substrate having a first surface and
a pedestal on the first surface of the template substrate, the
pedestal having a second surface spaced from the first surface in a
first direction perpendicular to the first surface. A pattern is
disposed on the second surface. The pedestal has a sidewall between
the first surface and the second surface that is at an angle of
less than 90.degree. to the second surface.
Inventors: |
KOBAYASHI; Kei; (Yokohama
Kanagawa, JP) ; MITRA; Anupam; (Yokohama Kanagawa,
JP) ; MORITA; Seiji; (Shinagawa Tokyo, JP) ;
KATO; Hirokazu; (Kariya Aichi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOSHIBA MEMORY CORPORATION |
Tokyo |
|
JP |
|
|
Appl. No.: |
17/518929 |
Filed: |
November 4, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16116402 |
Aug 29, 2018 |
11192282 |
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17518929 |
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International
Class: |
B29C 33/42 20060101
B29C033/42; B29C 35/08 20060101 B29C035/08; G03F 7/00 20060101
G03F007/00; B29C 37/00 20060101 B29C037/00; H01L 21/027 20060101
H01L021/027; B29C 43/02 20060101 B29C043/02; B29C 43/38 20060101
B29C043/38 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2018 |
JP |
2018-033833 |
Claims
1. A template for imprint patterning processes, comprising: a
template substrate having a first surface; and a pedestal on the
first surface of the template substrate, the pedestal having a
second surface spaced from the first surface in a first direction
perpendicular to the first surface, and a resin material pattern
disposed on the second surface.
2. The template according to claim 1, wherein the pattern is
disposed in a pattern arrangement region in a central portion of
the second surface surrounded on the second surface by a mark
arrangement region outside the pattern arrangement region between
the central portion and an outer edge of the second surface, and
the pattern arrangement region does not extend laterally along the
second surface beyond an outermost position of a projected outline
of a direct contact region between the pedestal and the first
surface.
3. The template according to claim 1, wherein the pedestal is a
resin material.
4. The template according to claim 1, wherein the pedestal and the
template substrate are formed of the same material.
5. A method of manufacturing a template for imprint patterning
processes, comprising: forming a guide layer on a first surface of
a template substrate, the guide layer having an opening exposing
the first surface, a sidewall of the opening including an angled
portion that extends to form an interior angle within the guide
layer that is less than 90.degree. with respect to the first
surface; depositing a curable material in the opening; curing the
curable material; and removing the guide layer while leaving the
cured curable material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 16/116,402, filed on Aug. 29, 2018, which is
based upon and claims the benefit of priority from Japanese Patent
Application No. 2018-033833, filed on Feb. 27, 2018, the entire
contents of each of which are incorporated herein by reference.
FIELD
[0002] Embodiments described herein relate generally to a template,
a template manufacturing method, and a semiconductor device
manufacturing method.
BACKGROUND
[0003] In the related art, when a template is pressed against a
resist material on a workpiece during imprint lithography
processing, the resist material seeps out from a periphery of a
pedestal portion of the template on which the imprint pattern is
disposed.
DESCRIPTION OF THE DRAWINGS
[0004] FIGS. 1A and 1B are views schematically illustrating a
template according to a first embodiment.
[0005] FIGS. 2A and 2B are cross-sectional views illustrating
additional aspects of the template according to a first
embodiment.
[0006] FIGS. 3A to 3E illustrate aspects of a sequence of a
manufacturing method of a template according to a first
embodiment.
[0007] FIG. 4 is a cross-sectional view schematically illustrating
one example of a template according to a second embodiment.
[0008] FIG. 5 is a cross-sectional view schematically illustrating
another example of a template according to a second embodiment.
[0009] FIGS. 6A to 6D illustrate aspects of a sequence of a
manufacturing method of a template according to a third
embodiment.
[0010] FIG. 7 is a cross-sectional view schematically illustrating
an example of a template according to a fourth embodiment.
[0011] FIGS. 8A to 8D illustrate aspects of a sequence of a
manufacturing method of a template according to a fourth
embodiment.
[0012] FIGS. 9A to 9D illustrate aspects of a sequence of a
semiconductor device manufacturing method including a template
according to a fourth embodiment.
[0013] FIGS. 10A and 10B are cross-sectional views schematically
illustrating a reproduction sequence of a template according to a
fourth embodiment.
[0014] FIG. 11 is a cross-sectional view schematically illustrating
a template according to a fifth embodiment.
[0015] FIG. 12 is a diagram schematically illustrating aspects
related to an adhesion layer and a template according to a fifth
embodiment.
[0016] FIGS. 13A to 13E illustrate aspects of a sequence of a
manufacturing method of a template according to a fifth
embodiment.
[0017] FIG. 14 is a cross-sectional view schematically illustrating
a template manufactured by a method described in conjunction with a
fourth embodiment.
[0018] FIGS. 15A and 15B are cross-sectional views schematically
illustrating aspects of a sequence of a manufacturing method of a
template according to a sixth embodiment.
DETAILED DESCRIPTION
[0019] Embodiments provide an imprint template, an imprint template
manufacturing method, and a semiconductor device manufacturing
method using an imprint template which can prevent a resist from
seeping out from a periphery of a pedestal portion of the template
during the imprint processing.
[0020] In general, according to one embodiment, a template for
imprint patterning processes comprises a template substrate having
a first surface and a pedestal on the first surface of the template
substrate. The pedestal has a second surface spaced from the first
surface of the template substrate in a first direction
perpendicular (normal) to the first surface. A pattern is disposed
on the second surface. The pedestal has a sidewall between the
first surface and the second surface that is at an angle of less
than 90.degree. to the second surface.
[0021] A template, a template manufacturing method, and a
semiconductor device manufacturing method according to example
embodiments will be hereinafter described in detail with reference
to the accompanying drawings. It is noted that the present
disclosure is not limited by these example embodiments.
First Embodiment
[0022] FIGS. 1A and 1B are views schematically illustrating an
example configuration of a template according to a first
embodiment. FIG. 1A is a top view, and FIG. 1B is a cross-sectional
view taken along a line A-A of FIG. 1A. A template 1 includes a
rectangular template substrate 2 and a pedestal portion 3 provided
on (or approximately so) a central portion of a first surface 21 of
template substrate 2.
[0023] The template substrate 2 has, for example, a generally
rectangular flat plate structure. The template substrate 2 is
formed of quartz glass or the like.
[0024] The pedestal portion 3 has a quadrangular pyramidal
structure. An uneven pattern 33 that is to be brought into contact
with a resist on a workpiece during the imprint processing is
provided on a first surface 31 of the pedestal portion 3. A pattern
arrangement region R.sub.P and a mark arrangement region R.sub.M
provided on an outer periphery of the pattern arrangement region
R.sub.P are provided on the first surface 31. In FIG. 1A, the
pattern arrangement region R.sub.p is rectangular, and the mark
arrangement region R.sub.m surrounds the pattern arrangement region
R.sub.p in a rectangular frame-like manner. A pattern,
corresponding to a wiring pattern or other device components, to be
transferred to the workpiece is formed in the pattern arrangement
region R.sub.P. Marks, particularly alignment marks for aligning
the template 1 with the workpiece are disposed in the mark
arrangement region R.sub.M.
[0025] A second surface 32 of the pedestal portion 3 adheres to the
first surface 21 of the template substrate 2. The pedestal portion
3 is formed of resin such as urethane rubber, silicone rubber, or
acrylate-based rubber. In addition, a thickness of the pedestal
portion 3 is not limited in particular; however, in some examples,
it is preferable that the thickness is approximately 10 .mu.m to 20
.mu.m.
[0026] The second surface 32 is smaller (in projected surface area)
than the first surface 31. Accordingly, side surfaces other than
the first surface 31 and the second surface 32 of the pedestal
portion 3 are angled from the second surface 32 toward the first
surface 31. That is, an angle .alpha. formed between the first
surface 31 and a side surface of the pedestal portion 3 is an acute
angle (less than 90 degrees). It is noted that the angle .alpha. is
more preferably greater than or equal to 30 degrees and is less
than or equal to 45 degrees. As such, by configuring the corner
portion on the first surface 31 side as an acute angle, the resist
is not extruded outward from the first surface 31, even if the
resist reaches a peripheral edge portion of the pedestal portion 3
when the template 1 is pressed against the resist on the workpiece
in the imprint processing. That is, it is possible to prevent the
resist from flowing along the side surface of the pedestal portion
3 during imprint processing.
[0027] FIGS. 2A and 2B illustrate an example of a configuration of
the template according to the first embodiment. The more acute the
angle .alpha. of the corner portion on the first surface 31 side
is, the more the resist can be prevented from being extruded to the
side surface of the pedestal portion 3. However, as the angle a of
the corner portion is reduced, an outer edge 321 of the second
surface 32 moves further towards the center of the pedestal portion
3. In FIG. 2A, a projected position 321a (a perpendicular line
drawn from the outer edge 321 of the second surface 32 towards the
first surface 31) of the outer edge 321 is within the mark
arrangement region R.sub.M (or alternatively described as outside
the pattern arrangement region R.sub.P). However, in FIG. 2B, the
position 321a is within the pattern arrangement region R.sub.P.
That is, for the arrangement depicted FIG. 2A, the full, maximum
thickness of pedestal portion 3 is below all portions of the
pattern arrangement region R.sub.P. However, for the arrangement
depicted in FIG. 2B, there is a region 325 in which the full,
maximum thickness the pedestal portion 3 is not provided below a
portion of the pattern arrangement region R.sub.P. Here, the "outer
edge" refers to an outer perimeter boundary of the second surface
32 at the interface with surface 21.
[0028] In the imprint processing, it is preferable that force is
applied as uniformly as possible in places where the template
pattern exists. Accordingly, for the case illustrated in FIG. 2A, a
more uniform force is applied to the resist contacting the pattern
arrangement region R.sub.P as compared to the case illustrated in
FIG. 2B, in which the region 325 is present below a portion of the
pattern arrangement region R.sub.P and the force applied to the
resist by the template 1 may be different at a position
corresponding to the region 325.
[0029] Therefore, it is preferable that the pedestal portion 3
exists at a uniform thickness below all portions of the pattern
arrangement region R.sub.P, as illustrated in FIG. 2A. Accordingly,
it is preferable that the angle .alpha. of the corner portion on
the first surface 31 side be selected such that the position 321a
will be in the mark arrangement region R.sub.M and not pattern
arrangement region R.sub.p.
[0030] Next, a method of manufacturing the template 1 will be
described. FIGS. 3A to 3E illustrate an example of a sequence of
the manufacturing method of a template 1 according to the first
embodiment. First, as illustrated in FIG. 3A, the template
substrate 2 is prepared. The template substrate 2 is formed of, for
example, quartz glass in a form of a rectangular flat plate.
Subsequently, a guide layer 51 is formed on the first surface 21 of
the template substrate 2. The guide layer 51 is formed on the first
surface 21 of the template substrate 2 so as to have an opening 52
having a rectangular shape in an overhead view, in which a width
decreases from an upper surface of the guide layer 51 toward a
lower surface (a boundary with the template substrate 2) of the
guide layer 51. Here, the width indicates, for example, a maximum
width of the opening 52 in any direction parallel to first surface
21. Aside surface 52a forming the opening 52 has a tapered shape.
The guide layer 51 is a material with etching selectivity different
from etching selectivity of an embedded material 34. In addition,
it is preferable that the guide layer 51 is a material that does
not substantially intermix with the embedded material 34 and can be
removed by a solvent. For example, polystyrene, polyurethane or the
like which is a chain polymer material can be used as the guide
layer 51.
[0031] The opening 52 in the guide layer 51 can be formed, for
example, by an imprinting process performed on the first surface 21
of the template substrate 2, using an imprint template (e.g., a
different template 1) having a rectangular convex pattern which is
pressed into a material of the guide layer 51. Alternatively, the
guide layer 51 and opening 52 can be formed by a photolithographic
process. At this time, the angle between the upper surface and the
side surface of the guide layer 51 is formed so as to be larger
than 90 degrees. That is, the interior angle of the side surface of
the guide layer 51 and the first surface 21 of the template
substrate 2 is less than 90 degrees.
[0032] Thereafter, the embedded material 34 is disposed in the
opening 52 as illustrated in FIG. 3B. The embedded material 34 is a
thermosetting resin or a photo-curing resin which, as initially
applied, is unset/uncured to at least some extent. The embedding
material 34 is, for example, a resin material that crosslinks such
as urethane rubber, silicone rubber, or acrylate-based rubber. In a
state depicted in FIG. 3B, the embedded material 34 is not cured
and is in a liquid or flowable state.
[0033] Next, as illustrated in FIG. 3C, an original plate 61 is
pressed against the embedded material 34, and a recess portion 611
of the original plate 61 is filled with the embedded material 34.
Thereafter, heat or light is applied to the embedded material 34,
and thereby, the embedded material 34 is cured. By doing so, the
embedded material 34 becomes the pedestal portion 3. The original
plate 61 is a template for pattern formation having a pattern of
protrusions and recesses formed thereon which is the inverse of the
pattern of protrusions and recesses to be formed on template 1. The
original plate 61 is formed of, for example, quartz glass and may
be referred to as a master template 61 in some contexts.
[0034] Next, as illustrated in FIG. 3D, the original plate 61 is
detached from the pedestal portion 3. Furthermore, as illustrated
in FIG. 3E, the guide layer 51 is removed by wet processing or the
like. In the wet processing, a chemical solution or solvent in
which the cured embedded material 34 does not dissolve but in which
the guide layer 51 does dissolve or otherwise is removed is used.
Thereby, the pedestal portion 3 having the uneven pattern 33 is
formed on the template substrate 2, and the template 1 is
completed.
[0035] In the first embodiment, the angle .alpha. between the first
surface 31 on which the pattern of the pedestal portion 3 of the
template 1 is formed and the side surface is less than 90 degrees.
As a result, when the template 1 is pressed against the resist on
the workpiece, it is possible to prevent or limit the resist from
seeping out from the peripheral edge portion of the pedestal
portion 3 and then flowing along the side surface of the pedestal
portion 3. As a result, a height of the resist seeping out to the
side surface of the pedestal portion 3 can be less than, for
example, 100 nm. In addition, defect in a shot region formed when
the next shot region is pressed can be reduced by the cured
resist.
Second Embodiment
[0036] In the first embodiment, the angle .alpha. formed between a
side surface and a first surface on which a pattern of a pedestal
portion is formed is less than 90 degrees. As the angle .alpha.
decreases, resist can be prevented from seeping out to the side
surface of the template 1, but in a structure of the first
embodiment, as described with reference to FIG. 2B, a pattern
arrangement region has to be provided within a projected perimeter
(outline) of the second surface of the pedestal portion.
Accordingly, when the angle .alpha. is reduced, a width of a kerf
region has to increase to make an area of the first surface of the
pedestal portion to be larger than a shot region. In the second
embodiment, a template capable of preventing a resist from seeping
from a peripheral edge portion of the pedestal portion while
keeping an area of the pedestal portion substantially the same size
as the shot region will be described.
[0037] FIG. 4 is a sectional view schematically illustrating an
example of a configuration of a template 1 according to the second
embodiment. In the second embodiment, a side surface of the
pedestal portion 3 is configured to have two distinct portions. A
first side surface portion 35a has a surface substantially
perpendicular to the first surface 21, and a second side surface
portion 35b intersects at an angle a less than 90 degrees with
respect to the first surface 31 are provided.
[0038] Since the angle .alpha. between the second side surface
portion 35b and the first surface 31 is less than 90 degrees, as a
distance from the first surface 21 increases, a position of an
outer edge of the second side surface portion 35b moves. In
addition, if a size (hereinafter, referred to as a height) of the
pedestal portion 3 in a thickness direction is constant, the angle
.alpha. formed between the first surface 31 and the second side
surface portion 35b can be changed by changing the length of the
first side surface portion 35a. That is, the greater the length of
the first side surface portion 35a is, the smaller the angle a will
be, and the shorter the length of the first side surface portion
35a, the larger the angle .alpha. is.
[0039] A position 35c, corresponding to the projected outer edge
position of the first side surface portion 35a, is not located in
the pattern arrangement region R.sub.P provided on the first
surface 31 but is located in the mark arrangement region R.sub.M.
This is because, if the projected position of the outer edge of the
first side surface portion 35a is in the pattern arrangement region
R.sub.P, it is impossible to uniformly apply a force to each
position of the resist in contact with the pattern arrangement
region R.sub.P, as described in the first embodiment. It is noted
that the same configuration elements as the configuration elements
of the first embodiment are denoted by the same reference numerals
or symbols, and description thereof will be omitted.
[0040] The template 1 of the second embodiment can be manufactured
by substantially the same manufacturing method as the manufacturing
method described in conjunction with the first embodiment. However,
the side surface 52a of the opening 52 of the guide layer 51 formed
on the template substrate 2 (see FIG. 3A) would need to be modified
from the first embodiment to include a part corresponding to the
first side surface portion 35a and a part corresponding to the
second side surface portion 35b.
[0041] FIG. 5 is a sectional view schematically illustrating
another example of the structure of a template 1 according to the
second embodiment. In FIG. 4, a case where the first side surface
portion 35a of the pedestal portion 3 stands perpendicularly to the
first surface 21 is illustrated. However, as illustrated in FIG. 5,
an interior angle .beta. between the first surface 21 and the first
side surface portion 35a may be less than 90 degrees. However, the
position 35c (that is, the position of closest approach to the
pattern arrangement region R.sub.P) where the outline of the first
side surface portion 35a is the smallest is projected onto the
first surface 31 of the pedestal portion 3 exists in the mark
arrangement region R.sub.M. In addition, while not specifically
illustrated, the angle .beta. formed between the first surface 21
of the template substrate 2 and the first side surface portion 35a
of the pedestal portion 3 may instead be larger than 90 degrees in
some embodiments. Furthermore, the first side surface portion 35a
may have a surface (R surface) with a curvature (radius of
curvature) or may have another surface shape.
[0042] According to the second embodiment, substantially the same
effects as the first embodiment can be obtained.
Third Embodiment
[0043] In the first embodiment, a pattern on template 1 is formed
by pressing an original template into an embedded material and
curing the embedded material. However, the disclosure is not
limited to this. In the third embodiment, another method of
manufacturing a template will be described.
[0044] FIGS. 6A to 6D are sectional views illustrating an example
of a sequence of a manufacturing method of a template according to
the third embodiment. As an initial step a process similar to those
described in conjunction with FIGS. 3A and 3B in the first
embodiment is performed. As such, the embedded material 34 is cured
by applying heat or light to the embedded material 34 buried in the
opening 52 of the guide layer 51. Then, the guide layer 51 is
removed. By doing so, an embedded portion 34a formed of a resin is
formed on the template substrate 2, as depicted in FIG. 6A. The
embedded portion 34a corresponds to a pedestal portion 3 on which
the pattern 33 has not been formed.
[0045] Next, as illustrated in FIG. 6B, an original plate 62 on
which a pattern has been formed is coated with a receiver material
36a. The receiver material 36a is applied onto the original plate
62 by using, for example, a spin coating method. The receiver
material 36a is filled into a recess pattern in the original plate
62. The original plate 62 is a template for pattern formation
having a pattern on one side. The original plate 62 is, for
example, a silicon substrate. Unlike the original plate 61
described in FIGS. 3A to 3E, the original plate 62 is not provided
with the pedestal portion 3. The receiver material 36a is, for
example, a resin material which crosslinks such as urethane rubber,
silicone rubber or acrylate-based rubber. In the state depicted in
FIG. 6B, the receiver material 36a is not cured and is a liquid or
flowable material.
[0046] Thereafter, as illustrated in FIG. 6C, the original plate 62
coated with the receiver material 36a is disposed so as to face the
embedded portion 34a1, and the receiver material 36a is brought
into contact with the embedded portion 34a. In this state, heat or
light is applied to the receiver material 36a, and the receiver
material 36a is cured and a transfer portion 36 is formed. The
transfer portion 36 is bonded to the embedded portion 34a.
[0047] Next, as illustrated in FIG. 6D, the template substrate 2 is
separated from the original plate 62. Thereby, the pedestal portion
3 on which the transfer portion 36 is provided is formed. As
described above, a template 1 corresponding to that depicted in
FIGS. 1A and 1B is completed.
[0048] In the third embodiment, it is possible to manufacture the
template 1 in which the angle .alpha. of the corner portion formed
between the first surface 31 and the side surface of the pedestal
portion 3 is less than 90 degrees, when the thin transfer portion
36 is discounted. Thereby, the following effect is achieved. That
is, it is possible to obtain the template 1 for which the resist
will not substantially seep out from the outer periphery portion of
the pedestal portion 3 during the template pressing.
Fourth Embodiment
[0049] In a fourth embodiment, a method of manufacturing a template
having a structure in which a transfer portion formed of a
patterned resin is provided on a pedestal portion of a template
substrate, will be described.
[0050] FIG. 7 is a sectional view schematically illustrating an
example of a configuration of a template 1 according to the fourth
embodiment. The template 1 according to the fourth embodiment
includes a template substrate 2a and the transfer portion 36. The
template substrate 2a has a configuration in which a pedestal
portion 24 is provided near a central portion of the first surface
21 of a rectangular substrate. The pedestal portion 24 has a
structure protruding by approximately 10 to 50 .mu.m with respect
of the rest of the template substrate 2a. In performing this
process, an angle formed between the side surface and a surface on
a side where the transfer portion 36 of the pedestal portion 24 is
disposed is not limited to an angle illustrated in FIG. 7. The
angle of the pedestal portion 24 may be greater than or equal to,
for example, 90 degrees. However, it is also possible to obtain the
effect described in the first embodiment by setting the angle of
the pedestal portion 24 to be less than 90 degrees. The template
substrate 2a is formed of quartz glass or the like.
[0051] The transfer portion 36 has a pattern of protrusions and
recesses on the first surface 361 and forms the patterned portion
of template 1. The second surface 362 opposite to the first surface
361 adheres onto the pedestal portion 24 of the template substrate
2a. As illustrated in FIG. 1A, the pattern arrangement region
R.sub.P, of a rectangular shape, and the mark arrangement region
R.sub.M, of a frame shape surrounding the pattern arrangement
region R.sub.P, are provided on the first surface 361. A pattern
disposed in the pattern arrangement region R.sub.P and a mark
disposed in the mark arrangement region R.sub.M are substantially
the same as the pattern and the mark described in conjunction with
the first embodiment. The transfer portion 36 is formed of a
flowable material including a reactive group for purposes of
curing/hardening the material. The material may be a
photo-initiated radical polymerizable material including at least
one reactive group selected from an acryloyl group, a methacryloyl
group, or a vinyl ether group, or a photo-initiated cationic
polymerizable material including at least one reactive group
selected from an epoxy group or an oxetanyl group is exemplified as
a reactive group for curing.
[0052] FIGS. 8A to 8D are cross-sectional views schematically
illustrating an example of a sequence for a manufacturing a
template 1 according to the fourth embodiment. First, as
illustrated in FIG. 8A, an original plate 62 having a pattern
etched therein corresponding to that to be formed on the template 1
is prepared. The original plate 62 is provided with a plurality of
recess portions 62a. The original plate 62 is, for example, a
silicon substrate.
[0053] Next, as illustrated in FIG. 8B, a receiver material 36a
that is a liquid is formed on the original plate by using a spin
coating method. The receiver material 36a is filled in the recess
portions 62a and a thickness of the receiver material 36a above the
pattern formation surface of the original plate is substantially
uniformized. A photo-curing resin or the like can be used as the
receiver material 36a.
[0054] Thereafter, the template substrate 2a is disposed such that
the pedestal portion 24 faces the receiver material 36a on the
original plate 62. The template substrate 2a is formed of quartz
glass or the like and is provided with the pedestal portion 24
having a height of approximately 10 to 50 .mu.m positioned near a
central portion of the first surface 21.
[0055] Next, as illustrated in FIG. 8C, the template substrate 2a
is brought into contact with the receiver material 36a. Thereafter,
the receiver material 36a in contact with the pedestal portion 24
is irradiated with ultraviolet rays. Thereby, the receiver material
36a in the region irradiated with the ultraviolet rays is cured to
form the solidified, cured transfer portion 36, but the receiver
material 36a in the regions not irradiated with the ultraviolet
rays remains in a liquid, uncured form.
[0056] Next, as illustrated in FIG. 8D, the template substrate 2a
is separated from the original plate 62. The transfer portion 36
(cured receiver material 36a) is peeled from the original plate 62
and the uncured receiver material 36a remains on the original plate
62. It is noted that the internal breaking strength (modulus) of
the transfer portion 36 is preferable to be greater than or equal
to 1.2.times.10.sup.-4 GPa. This is because, when the template 1 is
peeled from the resist in the imprint processing, the transfer
portion 36 might be broken unless the transfer portion has a
breaking stress greater than or equal to 1.2.times.10.sup.-4
GPa.
[0057] FIGS. 9A to 9D are cross-sectional views schematically
illustrating an example of a sequence of a method of manufacturing
a semiconductor device using a template 1 according to the fourth
embodiment. First, as illustrated in FIG. 9A, a resist 71 is
dispense onto a particular die or shot region of a workpiece 70.
The resist 71 is, for example, a photo-curing resin. The resist 71
is dispensed onto the workpiece 70 by using, for example, an inkjet
method. Alternatively, the resist 71 may be entirely coated over
the workpiece 70 by using the spin coating method. The workpiece 70
is a semiconductor substrate such as a silicon substrate, a
semiconductor film formed over a semiconductor substrate, a
conductive film, or an insulating film. Next, in a state where the
transfer portion 36 of the template 1 faces the workpiece 70, rough
positioning (coarse alignment) between the template 1 and the
workpiece 70 is performed.
[0058] Thereafter, as illustrated in FIG. 9B, at least one of the
template 1 and the workpiece 70 is moved until the transfer portion
36 comes into contact with the resist 71. Then, more precise
positioning (fine alignment) between the template 1 and the
workpiece 70 is performed. After the resist 71 is filled in recess
portions of the template 1, the resist 71 is irradiated with
ultraviolet rays to cure the resist 71. Thereby, a resist pattern
71a is formed.
[0059] Next, as illustrated in FIG. 9C, the template 1 is separated
from the resist pattern 71a. Thereafter, the workpiece 70 is
processed by using anisotropic etching, such as reactive ion
etching (RIE), using the resist pattern 71a as a mask. By repeating
this processing, the workpiece 70 can be processed to have a
desired pattern, and a semiconductor device having the desired
pattern is thereby manufactured.
[0060] Here, if a processing is repeated in which the template 1 is
pressed against the resist 71 on the workpiece 70 many times and
the resist 71 is separated from the resist pattern 71a after being
cured, the pattern of the transfer portion 36 might eventually be
damaged as illustrated in FIG. 9D. If the imprint processing is
performed by using a damaged template 1 (see FIG. 9D), the intended
resist pattern 71a is no longer able to be formed on the workpiece
70. In such a case, the damaged transfer portion 36 must be removed
and a new transfer portion 36 formed on the pedestal portion 24 of
the template substrate 2a, and thereby, the template 1 can be more
easily reproduced or repaired.
[0061] FIGS. 10A and 10B are cross-sectional views schematically
illustrating an example of a sequence for repairing the template 1
according to the fourth embodiment. First, as illustrated in FIG.
10A, the damaged transfer portion 36 of the template 1 is peeled or
otherwise removed by a cleaning process. For example, a sulfuric
acid hydrogen peroxide solution (sometimes referred to as piranha
etch) can be used as a cleaning solution, but the cleaning solution
may be appropriately changed depending on the material of the
transfer portion 36. Thereby, the template substrate 2a in which an
upper portion of the pedestal portion 24 has been cleaned is
obtained as illustrated in FIG. 10B.
[0062] Thereafter, in substantially the same manner as in the
method illustrated in FIGS. 8A to 8D, the template 1 is reproduced
by forming a new transfer portion 36 on the pedestal portion 24 of
the template substrate 2a. The remade template 1 can then be used
for manufacturing semiconductor devices as illustrated in FIGS. 9A
to 9D.
[0063] In the fourth embodiment, imprint processing is performed by
using the template 1 in which the resin transfer portion 36 having
a pattern adheres onto the pedestal portion 24. When the transfer
portion 36 is damaged, the transfer portion 36 can be removed and a
new transfer portion 36 can be formed on the pedestal portion 24.
When a template formed entirely of quartz glass is damaged, the
entire template must be discarded, but in the fourth embodiment,
the template 1 can be re-manufactured at a low cost, compared to
the manufacturing cost of a quartz glass template since generally,
the template substrate 2a is not damaged and can thus be reused
after only a relatively simple cleaning process.
[0064] In addition, after an upper portion of the original plate 62
is coated with the receiver material 36a by using the spin coating
method, the receiver material 36a in contact with the template
substrate 2a is cured. Accordingly, a film thickness of the
transfer portion 36 formed on the pedestal portion 24 of the
template substrate 2a can be substantially uniformized.
Fifth Embodiment
[0065] In the template manufacturing method according to the fourth
embodiment, after a receiver material is cured in a state of being
in contact with a template substrate and the template substrate is
separated from the original plate, occasionally the cured receiver
material might not adhere to the template substrate and thus might
remain on the original plate sometimes. In the fifth embodiment, a
method of avoiding such a case will be described.
[0066] FIG. 11 is a sectional view schematically illustrating an
example of a template according to the fifth embodiment. The
template 1 further includes an adhesion layer 5 between the
template substrate 2a and the transfer portion 36. A material
having an adhesion strength towards the transfer portion 36 that is
larger than the adhesion strength between the transfer portion 36
and the original plate 62 is used as the adhesion layer 5.
[0067] The adhesion layer 5 can provide improved adhesion strength
by incorporating a material providing hydrogen bonding to the
relevant surfaces/materials and/or covalent bonding linkages
between the template substrate 2a and the transfer portion 36. In
an example, adhesion layer 5 is formed of a material having a
reactive group that bonds with the transfer portion 36 and a
reactive group bonds with the template substrate 2a. As described
in the fourth embodiment, the transfer portion 36 also requires a
reactive group for curing. For example, in a case where the
transfer portion 36 has a photo radical polymerizable group, the
photo radical polymerizable group may also be the reactive group
for bonding with the transfer portion 36. The material containing a
photo radical polymerizable group contains at least one reactive
group selected from an acryloyl group, a methacryloyl group, and a
vinyl ether group. In addition, in a case where the transfer
portion 36 contains a photo cationic polymerizable group, the photo
cationic polymerizable group may also be the reactive group for
bonding with the transfer portion 36. The material containing a
photo cationic polymerizable group contains at least one reactive
group selected from an epoxy group and an oxetanyl group.
[0068] In a case where the template substrate 2a is formed of
quartz glass, a silane coupling agent can be used as a reactive
group for bonding with the template substrate 2a.
Monoalkoxysilanes, dialkoxysilanes, trialkoxysilanes,
monochlorosilanes, dichlorosilanes, trichlorosilanes, and the like
can be used as the silane coupling agent. Accordingly, for example,
a silane coupling agent also containing a photo radical
polymerizable group, a silane coupling agent also containing a
photo cationic polymerizable group, or the like can be used as the
adhesion layer 5.
[0069] 3-(Trimethoxysilyl)propyl acrylate,
3-[diethoxy(methyl)silyl]propyl methacrylate,
3-(trimethoxysilyl)propyl methacrylate,
3-[tris(trimethylsilyloxy)silyl]propyl methacrylate,
3-[Dimethoxy(methyl)silyl]propyl methacrylate,
3-(methoxydimethylsilyl)propyl acrylate, 3-(triethoxysilyl)propyl
methacrylate, 3-(triallylsilyl)propyl acrylate,
3-(triallylsilyl)propyl methacrylate,
diethoxy(3-glycidyloxypropyl)methylsilane,
3-glycidyloxypropyltrimethoxysilane,
3-glycidyloxypropyl(dimethoxy)methylsilane,
[8-(glycidyloxy)-n-octyl]trimethoxysilane,
triethoxy(3-glycidyloxypropyl)silane, and the like can be used as
the adhesion layer 5 in various example embodiments.
[0070] FIG. 12 is a diagram schematically illustrating a role of
the adhesion layer in the template 1 according to the fifth
embodiment. Here, a case where 3-(trimethoxysilyl)propyl acrylate
is used as the adhesion layer 5 is taken as an example. As
illustrated in FIG. 12, a trimethoxysilyl group of the adhesion
layer 5 bonds to the template substrate 2a formed of quartz glass
by a silane coupling reaction. The acryloyl group of the adhesion
layer 5 bonds to the transfer portion 36 in the photo
polymerization reaction used for curing of the transfer portion 36.
As such, the adhesion layer 5 can make the template substrate 2a
more firmly adhere to the transfer portion 36.
[0071] If the acryloyl group is switched to an epoxy group, which
is a photo cationic polymerizable group, the epoxy group bonds to
the transfer portion 36 by a photo cationic polymerization reaction
during curing of the transfer portion 36.
[0072] FIGS. 13A to 13E are cross-sectional view schematically
illustrating an example of a sequence of a manufacturing method of
a template 1 according to the fifth embodiment. Here, a case where
the adhesion layer 5 and the receiver material 36a are configured
with a material containing a photo radical polymerizable group will
be described as an example.
[0073] First, as illustrated in FIG. 13A, the adhesion layer 5 is
formed on the pedestal portion 24 of the template substrate 2a by
using a film formation method such as a vapor deposition method.
Here, 3-(trimethoxysilyl)propyl acrylate is used for the adhesion
layer 5, the trimethoxysilyl group bonds to the template substrate
2a, which is formed of quartz glass, through a silane coupling
reaction during the vapor deposition process, and thereby, the
adhesion layer 5 is formed.
[0074] Next, as illustrated in FIG. 13B, the original plate 62 is
prepared, and the receiver material 36a is formed on the entire
surface of the original plate 62 by using the spin coating
method.
[0075] Thereafter, the template substrate 2a is disposed such that
the pedestal portion 24 faces the receiver material 36a on the
original plate 62. Next, as illustrated in FIG. 13C, the template
substrate 2a and the receiver material 36a are brought into
contact. However, unlike the case of FIG. 8C, the receiver material
36a is brought into direct contact with the adhesion layer 5 formed
on the pedestal portion 24 instead of the pedestal portion 24.
During this contacting process, the template substrate 2a and the
original plate 62 are disposed in an atmosphere in which the curing
reaction is inhibited. That is, in a case where the receiver
material 36a containing a photo radical polymerizable group is
used, the atmosphere contains oxygen.
[0076] Thereafter, as illustrated in FIG. 13D, a region including
the pedestal portion 24 is irradiated with ultraviolet rays. By
doing so, the adhesion layer 5 and the receiver material 36a are
bonded to each other by the photo radical polymerization reaction
and are cured in the irradiated region where the adhesion layer 5
and the receiver material 36a are in contact with each other. As a
result, the receiver material 36a becomes the transfer portion 36.
It is preferable that only a region corresponding to the pedestal
portion 24 is irradiated with ultraviolet rays, but generally a
wider region than the region exactly corresponding to the pedestal
portion 24 will usually be irradiated with the ultraviolet rays.
Since the pedestal portion 24 protrudes from the first surface 21
of the template substrate 2a, a periphery of the pedestal portion
24 is filled in an atmosphere containing oxygen. In an oxygen rich
atmosphere, a photo radical polymerizable curing reaction will not
substantially progress and the receiver material 36a exposed to the
oxygen rich atmosphere during irradiation is hardly solidified, and
thus, even if some periphery of the pedestal portion 24 is
irradiated with ultraviolet rays, the receiver material 36a
disposed beyond the pedestal portion 254 will not be substantially
cured and therefor remains in a liquid form in those regions which
are not in direct contact with the adhesion layer 5.
[0077] Next, as illustrated in FIG. 13E, the template substrate 2a
is separated from the original plate 62. The transfer portion 36 is
peeled not from the template substrate 2a but from a boundary with
the original plate 62 without being broken. In addition, since the
receiver material 36a is not cured in regions other than the region
corresponding to the pedestal portion 24 of the template substrate
2a, the breaking stress of the transfer portion 36 in the region
corresponding to the pedestal portion 24 is larger than the
breaking stress of the receiver material 36a in the regions other
than the region corresponding to the pedestal portion 24.
Accordingly, when being separated, the transfer portion 36 is
cleanly peeled at a boundary between the region corresponding to
the pedestal portion 24 and the other regions.
[0078] The adhesion layer 5 and the receiver material 36a can be
configured with a material containing a photo cationic
polymerizable group. In such cases, when these materials are in an
atmosphere including water vapor, the photo cationic polymerization
curing reaction will be inhibited (similarly to inhibition of the
radical polymerization curing reaction by the presence of oxygen).
Accordingly, in a case where the adhesion layer 5 and the receiver
material 36a are configured with a material containing a photo
cationic polymerizable group, the template substrate 2a and the
original plate 62 are disposed in an atmosphere containing water
vapor before the ultraviolet rays are applied in FIG. 13D. By doing
so, the adhesion layer 5 and the receiver material 36a are bonded
to each other and cured by photo cationic polymerization reaction
in the region where the adhesion layer 5 and the receiver material
36a are in contact with each other. In the other regions where the
receiver material 36a is not in contact with the adhesion layer 5,
the receiver material 36a is not cured due to inhibition by water
vapor and thus remains in a liquid form.
[0079] The same effect as in the fourth embodiment can also be
obtained in the fifth embodiment.
Sixth Embodiment
[0080] FIG. 14 is a cross-sectional view schematically illustrating
an example of a template manufactured by using the method described
in the fourth embodiment. As illustrated in FIG. 14, the transfer
portion 36 is provided on the pedestal portion 24 of the template
substrate 2a; however, a peripheral edge portion of the transfer
portion 36 in contact with the pedestal portion 24 may occasionally
be formed having an unintended, irregular shape. For example, a
portion 363 of the peripheral edge portion of the transfer portion
36 may protrude more in a lateral direction than an outer edge of
the pedestal portion 24. If the imprint processing is performed by
using such a template, there is a possibility that the portion
protruding in the lateral direction would interfere with a resist
pattern formed or to be formed in an adjacent shot or die region.
In addition, the same problem may occur with the fifth embodiment.
In the sixth embodiment, a method of manufacturing a template that
can prevent such a problem from occurring will be described.
[0081] FIGS. 15A and 15B are cross-sectional views schematically
illustrating an example of a sequence of a template manufacturing
method according to the sixth embodiment. FIG. 15A illustrates the
template 1 after separation from the original plate 62 as in FIG.
8D. As illustrated in FIG. 15A, the transfer portion 36 includes a
convex portion (convex pattern) 365 and a residual film portion 366
having a substantially uniform thickness on the pedestal portion 24
of the template substrate 2a. A recess portion (recess pattern) is
a region surrounded by or between the convex portion 365. As
illustrated in FIG. 14, a peripheral edge portion of the residual
film portion 366 may occasionally protrude outside of the pedestal
portion 24.
[0082] As illustrated in FIG. 15B, an etch-back process is
performed by anisotropic dry etching, such as a RIE method, until
exposed portions of the residual film portion 366 are removed.
[0083] It is noted that a case corresponding to the fourth
embodiment is described as an example here, but both exposed
portions of the residual film portion 366 and the adhesion layer
(present as in the fifth embodiment) can be removed in the
etch-back process.
[0084] Likewise, in the sixth embodiment, the receiver material 36a
is cured, the template substrate 2a is separated from the original
plate 62, and thereafter, the exposed portions of the residual film
portion 366 can be removed by anisotropic etching. By doing so, it
is possible to prevent the peripheral edge portion of the residual
film portion 366 from protruding in the lateral direction and
interfering with a resist pattern formed or to be formed in the
adjacent regions.
[0085] While certain embodiments have been described, these
embodiments have been presented by way of examples only, and are
not intended to limit the scope of the inventions. Indeed, the
novel embodiments described herein may be embodied in a variety of
other forms; furthermore, various omissions, substitutions and
changes in the form of the embodiments described herein may be made
without departing from the spirit of the inventions. The
accompanying claims and their equivalents are intended to cover
such forms or modifications as would fall within the scope and
spirit of the inventions.
* * * * *