U.S. patent application number 15/804433 was filed with the patent office on 2019-05-09 for apparatus for imprint lithography comprising a logic element configured to generate a fluid droplet pattern and a method of using such apparatus.
The applicant listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Edward Brian Fletcher, Amir Tavakkoli Kermani Ghariehali.
Application Number | 20190139789 15/804433 |
Document ID | / |
Family ID | 66327587 |
Filed Date | 2019-05-09 |
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United States Patent
Application |
20190139789 |
Kind Code |
A1 |
Tavakkoli Kermani Ghariehali; Amir
; et al. |
May 9, 2019 |
APPARATUS FOR IMPRINT LITHOGRAPHY COMPRISING A LOGIC ELEMENT
CONFIGURED TO GENERATE A FLUID DROPLET PATTERN AND A METHOD OF
USING SUCH APPARATUS
Abstract
An apparatus for imprint lithography can include a logic element
configured to generate a fluid droplet pattern of fluid droplets of
a formable material to be dispensed onto a substrate. The fluid
droplet pattern includes an imprint field, wherein the imprint
field has a side and a drop exclusion zone along the side, and the
drop exclusion zone is narrower at a first point farther from the
center of a side and wider at a second point closer to the center
of the side. In another aspect, a method can be carried out using
the apparatus. The apparatus and method can be useful in filling an
imprint field with a formable material relatively quickly without
extrusion defects or other complications.
Inventors: |
Tavakkoli Kermani Ghariehali;
Amir; (Austin, TX) ; Fletcher; Edward Brian;
(Austin, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Family ID: |
66327587 |
Appl. No.: |
15/804433 |
Filed: |
November 6, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03F 7/0002 20130101;
B41M 3/006 20130101; H01L 21/6715 20130101; B41J 2/2132 20130101;
B41J 2/005 20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; B41M 3/00 20060101 B41M003/00; G03F 7/00 20060101
G03F007/00; B41J 2/005 20060101 B41J002/005 |
Claims
1. An apparatus for imprint lithography comprising a logic element
configured to generate a fluid droplet pattern of fluid droplets of
a formable material to be dispensed onto a substrate, wherein the
fluid droplet pattern includes an imprint field, wherein: the
imprint field has a side and a drop exclusion zone along the side;
and the drop exclusion zone is narrower at a first point farther
from a center of the side and wider at a second point closer to the
center of the side.
2. The apparatus of claim 1, wherein the fluid droplet pattern is
organized in rows, wherein each row includes a terminal fluid
droplet along a boundary of the drop exclusion zone.
3. The apparatus of claim 2, wherein: a first terminal fluid
droplet is along a first row, and a second terminal fluid droplet
is along a second row; the center of the side of the imprint field
is closer to the second terminal fluid droplet than to the first
terminal fluid droplet; and the first terminal fluid droplet has a
corresponding first DEE, and the second terminal fluid droplet has
a corresponding second DEE that is longer than the first DEE.
4. The apparatus of claim 3, wherein: the fluid droplet pattern is
arranged in rows that extend in a translating direction and has a
translating fluid droplet pitch; and a difference between the
second and first DEEs is less than the translating fluid droplet
pitch.
5. The apparatus of claim 1, wherein an angle between the side of
the imprint field and a length of a fluid dispenser is configured
to be changed during a pass or between different passes.
6. The apparatus of claim 5, wherein a fluid dispense system
comprises a first fluid dispenser and a second fluid dispenser.
7. The apparatus of claim 6, wherein the first and second fluid
dispensers are in different rotational directions with respect to
the side of the imprint field.
8. The apparatus of claim 6, wherein the first fluid dispenser and
the second fluid dispenser are along different sides of the imprint
field.
9. The apparatus of claim 6, wherein the first fluid dispenser and
the second fluid dispenser are along adjacent sides of the imprint
field.
10. The apparatus of claim 9, wherein: the first fluid dispenser
has a length that lies along a first line; the second fluid
dispenser has a length that lies along a second line; and the first
and second lines intersect at an angle other than 90.degree..
11. An imprint lithography method, the method comprising:
generating a fluid droplet pattern of fluid droplets of a formable
material to be dispensed onto a substrate, wherein the fluid
droplet pattern includes an imprint field, wherein: the imprint
field has a side and a drop exclusion zone along the side; and the
drop exclusion zone is narrower at a first point farther from a
center of the side and wider at a second point closer to the center
of the side; and dispensing fluid droplets of the formable material
onto the substrate corresponding to the fluid droplet pattern.
12. The method of claim 11, wherein dispensing the fluid droplets
of the formable material is performed during a single pass using a
first fluid dispenser and a second fluid dispenser that are in
different rotational positions with respect to each other.
13. The method of claim 11, wherein dispensing the fluid droplets
of the formable material comprises: dispensing a first set of the
fluid droplets using a fluid dispenser during a first pass;
rotating the fluid dispenser, the substrate, or both; and
dispensing a second set of the fluid droplets using the fluid
dispenser during a second pass.
14. The method of claim 11, wherein dispensing the fluid droplets
of the formable material comprises: dispensing a first set of the
fluid droplets using a first fluid dispenser and a second set of
fluid droplets using a second fluid dispenser during a pass; and
rotating the first fluid dispenser, the second fluid dispenser, the
substrate or any combination during the pass.
15. The method of claim 11, further comprising providing an
apparatus having a fluid dispense system that includes a first
fluid dispenser and a second fluid dispenser, wherein: the first
fluid dispenser and the second fluid dispenser are oriented along
adjacent sides of the imprint field before dispensing the fluid
droplets; the first fluid dispenser has a length that lies along a
first line; the second fluid dispenser has a length that lies along
a second line; and the first and second lines intersect at an angle
other than 90.degree..
16. The method of claim 15, wherein dispensing the fluid droplets
of the formable material comprises: dispensing a first set of the
fluid droplets using the first fluid dispenser; and dispensing a
second set of the fluid droplets using the second fluid
dispenser.
17. The method of claim 11, wherein generating the fluid droplet
pattern is performed such that, wherein on an intra-row basis,
fluid droplets from each of first and second passes or different
fluid dispensers along a row has a predetermined local volume of
the formable material.
18. The method of claim 17, wherein the fluid droplets from the
first and second passes meet at a junction that is spaced apart
from a central portion of the imprint field.
19. A method of manufacturing an article, the method comprising:
providing a fluid dispense system having fluid dispense ports;
generating a fluid droplet pattern of fluid droplets of a formable
material to be dispensed onto a substrate, wherein the fluid
droplet pattern includes an imprint field, wherein: the imprint
field has a side and a drop exclusion zone along the side; and the
drop exclusion zone is narrower at a first point farther from a
center of the side and wider at a second point closer to the center
of the side; and moving a substrate of the article and the fluid
dispense ports relative to each other; dispensing fluid droplets of
the formable material onto the substrate corresponding to the fluid
droplet pattern; contacting the formable material with the template
having a patterned surface; and curing the formable material to
form a patterned layer corresponding to the patterned surface of
the template.
20. The method of claim 19, wherein the article includes an
electronic device, and the substrate includes a semiconductor
wafer.
Description
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to apparatuses for imprint
lithography, and more particularly to apparatuses including a logic
element to generate a fluid droplet pattern.
RELATED ART
[0002] Imprint lithography apparatuses and processes are useful in
forming nanoscale patterns on semiconductor wafers in the
fabrication of electronic devices. Such apparatuses and processes
can include the use of fluid dispense systems for depositing a
formable material, for example, a polymerizable material, such as a
resin or a resist, onto the wafer, using techniques such as fluid
droplet dispense. The dispensed material is contacted with an
imprint template (or mold) having desired pattern features and then
solidified, forming a patterned layer on the wafer. Template
feature fill rates and related defects are dependent, in part, on
template pattern feature density and orientation and the droplet
pattern arrangement, including the fluid droplet pitch.
[0003] Traditional fluid dispense systems permit have a rectilinear
pattern of fluid droplet. Such a pattern may take a significant
amount of time to form properly features and a residual layer
corresponding to a template. Thus, there continues to be an
industry demand for droplet pattern processes that allow for
quicker times to form properly resist patterns.
SUMMARY OF THE DISCLOSED EMBODIMENTS
[0004] In an aspect, an apparatus for imprint lithography can
include a logic element configured to generate a fluid droplet
pattern of fluid droplets of a formable material to be dispensed
onto a substrate, wherein the fluid droplet pattern includes an
imprint field, wherein the imprint field has a side and a drop
exclusion zone along the side, and the drop exclusion zone is
narrower at a first point farther from a center of the side and
wider at a second point closer to the center of the side.
[0005] In an embodiment, the fluid droplet pattern is organized in
rows, wherein each row includes a terminal fluid droplet along a
boundary of the drop exclusion zone.
[0006] In a particular embodiment, a first terminal fluid droplet
is along a first row, and a second terminal fluid droplet is along
a second row, the center of the side of the imprint field is closer
to the second terminal fluid droplet than to the first terminal
fluid droplet, and the first terminal fluid droplet has a
corresponding first DEE, and the second terminal fluid droplet has
a corresponding second DEE that is longer than the first DEE.
[0007] In a more particular embodiment, the fluid droplet pattern
is arranged in rows that extend in a translating direction and has
a translating fluid droplet pitch, and a difference between the
second and first DEEs is less than the translating fluid droplet
pitch.
[0008] In another embodiment, an angle between the side of the
imprint field and a length of a fluid dispenser is configured to be
changed during a pass or between different passes.
[0009] In a particular embodiment, a fluid dispense system
comprises a first fluid dispenser and a second fluid dispenser.
[0010] In a more particular embodiment, the first and second fluid
dispensers are in different rotational directions with respect to
the side of the imprint field.
[0011] In another more particular embodiment, the first fluid
dispenser and the second fluid dispenser are along different sides
of the imprint field.
[0012] In a further more particular embodiment, the first fluid
dispenser and the second fluid dispenser are along adjacent sides
of the imprint field.
[0013] In an even more particular embodiment, the first fluid
dispenser has a length that lies along a first line, the second
fluid dispenser has a length that lies along a second line, and the
first and second lines intersect at an angle other than
90.degree..
[0014] In another aspect, an imprint lithography method can include
generating a fluid droplet pattern of fluid droplets of a formable
material to be dispensed onto a substrate, wherein the fluid
droplet pattern includes an imprint field, wherein: the imprint
field has a side and a drop exclusion zone along the side; and the
drop exclusion zone is narrower at a first point farther from a
center of the side and wider at a second point closer to the center
of the side; and dispensing fluid droplets of the formable material
onto the substrate corresponding to the fluid droplet pattern.
[0015] In an embodiment, dispensing the fluid droplets of the
formable material is performed during a single pass using a first
fluid dispenser and a second fluid dispenser that are in different
rotational positions with respect to each other.
[0016] In another embodiment, dispensing the fluid droplets of the
formable material comprises dispensing a first set of the fluid
droplets using a fluid dispenser during a first pass; rotating the
fluid dispenser, the substrate, or both; and dispensing a second
set of the fluid droplets using the fluid dispenser during a second
pass.
[0017] In still another embodiment, dispensing the fluid droplets
of the formable material comprises dispensing a first set of the
fluid droplets using a first fluid dispenser and a second set of
fluid droplets using a second fluid dispenser during a pass, and
rotating the first fluid dispenser, the second fluid dispenser, the
substrate or any combination during the pass.
[0018] In a further embodiment, the method of claim further
comprises providing an apparatus having a fluid dispense system
that includes a first fluid dispenser and a second fluid dispenser,
wherein: the first fluid dispenser and the second fluid dispenser
are oriented along adjacent sides of the imprint field before
dispensing the fluid droplets; the first fluid dispenser has a
length that lies along a first line; the second fluid dispenser has
a length that lies along a second line; and the first and second
lines intersect at an angle other than 90.degree..
[0019] In a particular embodiment, dispensing the fluid droplets of
the formable material comprises dispensing a first set of the fluid
droplets using the first fluid dispenser, and dispensing a second
set of the fluid droplets using the second fluid dispenser.
[0020] In another embodiment, generating the fluid droplet pattern
is performed such that, wherein on an intra-row basis, fluid
droplets from each of first and second passes or different fluid
dispensers along a row has a predetermined local volume of the
formable material.
[0021] In a particular embodiment, the fluid droplets from the
first and second passes meet at a junction that is spaced apart
from a central portion of the imprint field.
[0022] In a further aspect, a method of manufacturing an article
can include: providing a fluid dispense system having fluid
dispense ports; generating a fluid droplet pattern of fluid
droplets of a formable material to be dispensed onto a substrate,
wherein the fluid droplet pattern includes an imprint field,
wherein: the imprint field has a side and a drop exclusion zone
along the side; and the drop exclusion zone is narrower at a first
point farther from a center of the side and wider at a second point
closer to the center of the side; and moving a substrate of the
article and the fluid dispense ports relative to each other;
dispensing fluid droplets of the formable material onto the
substrate corresponding to the fluid droplet pattern; contacting
the formable material with the template having a patterned surface;
and curing the formable material to form a patterned layer
corresponding to the patterned surface of the template.
[0023] In an embodiment, the article includes an electronic device,
and the substrate includes a semiconductor wafer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Embodiments are illustrated by way of example and are not
limited in the accompanying figures.
[0025] FIG. 1 includes an illustration of a side view of an
exemplary imprint lithography system.
[0026] FIG. 2 includes an illustration of a fluid droplet
pattern.
[0027] FIG. 3 includes an illustration of another fluid droplet
pattern.
[0028] FIG. 4 includes an illustration of a side view of a portion
of a fluid dispenser and fluid dispense ports.
[0029] FIG. 5 includes an illustration of a set of fluid dispensers
and part of a fluid droplet pattern for an imprint field having
fluid droplets near opposing sides of an imprint field.
[0030] FIG. 6 includes an illustration of a fluid dispenser and
part of a fluid droplet pattern for an imprint field having fluid
droplets near opposing sides of an imprint field that can be
generated using two dispense passes.
[0031] FIG. 7 includes an illustration of a fluid dispenser and
part of a fluid droplet pattern for an imprint field having fluid
droplets near opposing sides of an imprint field that can be
generated using two dispense passes.
[0032] FIG. 8 includes an illustration of fluid dispensers and part
of a fluid droplet pattern for an imprint field having fluid
droplets near opposing sides of an imprint field that can be
generated using two dispense passes.
[0033] FIG. 9 includes an illustration of fluid dispensers and part
of a fluid droplet pattern for an imprint field having fluid
droplets from different passes stitched together.
[0034] FIG. 10 includes an illustration of a fluid dispenser and a
fluid droplet pattern for an imprint field having fluid droplets
where rotation in a Y-Z plane is used.
[0035] FIG. 11 includes an illustration of a fluid dispenser and a
fluid droplet pattern for an imprint field having fluid droplets
where rotation in a Y-Z plane is used.
[0036] FIG. 12 includes an illustration of fluid dispensers and a
fluid droplet pattern for an imprint field having fluid droplets
where rotation in a Y-Z plane is used.
[0037] FIG. 13 includes a flow chart of an exemplary method of
forming an article, including generating a fluid droplet pattern
using the apparatus of FIG. 1.
[0038] Skilled artisans appreciate that elements in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements in the figures may be exaggerated relative to other
elements to help improve understanding of embodiments of the
invention.
DETAILED DESCRIPTION
[0039] The following description in combination with the figures is
provided to assist in understanding the teachings disclosed herein.
The following discussion will focus on specific implementations and
embodiments of the teachings. This focus is provided to assist in
describing the teachings and should not be interpreted as a
limitation on the scope or applicability of the teachings.
[0040] The term "terminal fluid droplet," when a fluid droplet
pattern is organized in rows, columns, or rows and columns, is
intended to mean a fluid drop along such row or column that is
closest to a side of an imprint field. A row or column can have
terminal fluid droplets at opposite ends of such row or column.
[0041] The term "drop edge exclusion" or "DEE" is intended to mean
a shortest distance between a terminal fluid droplet and its
adjacent side of an imprint field. Each side can have a plurality
of DEEs with each DEE corresponding to a row or column of fluid
droplets.
[0042] The term "drop exclusion zone" or "DEZ" is intended to mean
an area of an imprint field defined by a side of the imprint field
and a line passing through centers of terminal fluid droplets that
are closest to such side.
[0043] The term "pitch" is intended to mean a distance from a
center of a feature to a center of a next adjacent feature. For a
fluid droplet pattern, the fluid droplet pitch is a distance from
the center of a fluid droplet to the center of the next adjacent
fluid droplet. In Cartesian coordinates, a two-dimensional pattern
(a pattern as seen from a top view) can have a pitch in the
X-direction that corresponds to the distance between the centers of
the features as measured in the X-direction (X-direction pitch),
and a pitch in the Y-direction that corresponds to the distance
between the centers of the features as measured in the Y-direction
(Y-direction pitch). The X-direction pitch may be the same or
different from the Y-direction pitch.
[0044] As used herein, velocity and motion may be described on a
relative basis. For example, object A and object B move relative to
each other. Such terminology is intended to cover object A is
moving, and object B is not; object A is not moving, and object B
is moving; and both of objects A and B are moving.
[0045] Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which this invention belongs. The
materials, methods, and examples are illustrative only and not
intended to be limiting. To the extent not described herein, many
details regarding specific materials and processing acts are
conventional and may be found in textbooks and other sources within
the imprint and lithography arts.
[0046] A fluid droplet pattern can be formed that allows for
quicker filling of an imprint field without extrusion defects or
other complications. In an aspect, an apparatus for imprint
lithography can include a logic element configured to generate a
fluid droplet pattern of fluid droplets of a formable material to
be dispensed onto a substrate. The fluid droplet pattern can
include an imprint field, wherein the imprint field has a side and
drop exclusion zone along the side. The drop exclusion zone can be
narrower at a first point farther from a center of the side and
wider at a second point closer to the center of the side. In
another aspect, the apparatus can be used is performing a method to
form the fluid droplet pattern on the substrate.
[0047] Details regarding the apparatus and method are better
understood after reading this specification in conjunction with
figures. The description below is meant to illustrate embodiments
and not limit the scope of the present invention, which is defined
in the appended claims.
[0048] Referring to FIG. 1, a lithographic system 10 in accordance
with an embodiment described herein can be used to form a relief
pattern on a substrate 12. The substrate 12 may be coupled to a
substrate chuck 14. As illustrated, the substrate chuck 14 is a
vacuum chuck; however, in other embodiments the substrate chuck 14
may be any chuck including vacuum, pin-type, groove-type,
electrostatic, electromagnetic, or the like. The substrate 12 and
substrate chuck 14 may be further supported by a stage 16. The
stage 16 may provide translating or rotational motion along the X-,
Y-, or Z-directions. The stage 16, substrate 12, and substrate
chuck 14 may also be positioned on a base (not illustrated).
[0049] Spaced-apart from the substrate 12 is a template 18. The
template 18 can include a body having a first side and a second
side with one side having a mold 20 extending therefrom towards the
substrate 12. The mold 20 is sometimes referred to as a mesa. In an
embodiment, the template 18 can be formed without a mold 20.
[0050] The template 18, mold 20, or both may be formed from such
materials including fused-silica, quartz, silicon, organic
polymers, siloxane polymers, borosilicate glass, fluorocarbon
polymers, metal, hardened sapphire, other similar materials, or any
combination thereof. The template 18 and mold 20 can include a
single piece construction. Alternatively, the template 18 and mold
20 can include separate components coupled together. As
illustrated, an imprint surface 22 of the mold 20 includes features
defined by spaced-apart recesses 24 and protrusions 26. The imprint
surface 22 may define any original pattern that forms the basis of
a pattern to be formed on the substrate 12. In another embodiment,
the imprint surface 22 can be a blank, that is, the imprint surface
22 does not have any recesses or protrusions.
[0051] The template 18 can be coupled to a chuck 28. The chuck 28
can be configured as vacuum, pin-type, groove-type, electrostatic,
electromagnetic, or another similar chuck type. In an embodiment,
the chuck 28 may be coupled to an imprint head 30 such that the
chuck 28 or imprint head 30 can facilitate movement of the template
18.
[0052] The lithographic system 10 can further include a fluid
dispense system 32 used to deposit a formable material 34 on the
substrate 12. For example, the formable material 34 can include a
polymerizable material, such as a resin. The formable material 34
can be positioned on the substrate 12 in one or more layers using
techniques such as droplet dispense, spin-coating, dip coating,
chemical vapor deposition (CVD), physical vapor deposition (PVD),
thin film deposition, thick film deposition, or combinations
thereof. The formable material 34 can be dispensed upon the
substrate 12 before or after a desired volume is defined between
the mold 20 and the substrate 12, depending on design
considerations. For example, the formable material 34 can include a
monomer mixture that can be cured using ultraviolet light, heat, or
the like.
[0053] The lithographic system 10 can further include an energy
source 38 coupled to a direct energy 40 along a path 42. The
imprint head 30 and stage 16 can be configured to position the
template 18 and substrate 12 in superimposition with the path 42.
The lithographic system 10 can be regulated by a logic element 54
in communication with the stage 16, imprint head 30, fluid dispense
system 32, or source 38, and may operate on a computer readable
program, optionally stored in memory 56. The logic element 54 may
be a processor (for example, a central processing unit of a
microprocessor or microcontroller), a field-programmable gate array
(FPGA), an application specific integrated circuit (ASIC), or the
like. The processor, FPGA, or ASIC can be within the apparatus. In
another embodiment (not illustrated), the logic element can be a
computer external to the apparatus 10 and is bidirectionally
coupled to the apparatus 10.
[0054] While the formation of a patterned layer over the substrate
12 using the formable material 34 is relatively simple on a
conceptual basis, the patterned layer is significantly difficult,
particularly in view of the small dimensions, avoiding direct
contact between the template 18 and the substrate 12, and desire
for high throughput for the apparatus 10. In this specification,
new fluid droplet patterns can be used to achieve relatively high
volume production for the apparatus and without increasing defects,
such as extrusion defects.
[0055] U.S. Pat. No. 8,556,616 illustrates a fluid droplet pattern
and how the fluid droplets coalesce when a template contacts the
fluid droplets. In particular, FIG. 9 of U.S. Pat. No. 8,556,616
illustrates a fluid droplet pattern before a template contacts the
fluid droplets 54. FIGS. 17 to 20 of U.S. Pat. No. 8,556,616
include illustrations of how the fluid droplets 54 coalesce and
form an interface 88, which represents a fluid front, that moves
from the center of an imprint field radially outward at different
points in time. As can be seen in FIG. 20, the interface 88 reaches
centers along the sides of the imprint field before reaching
corners of the imprint field. By the time the interface 88 moves
significantly closer to the corners (at a point in time later than
FIG. 20), the likelihood of an extrusion defect near the center of
any one or more of the sides is significantly higher.
[0056] An extrusion defect is a portion of a resist layer that
extends beyond any side of the mold 20 during the imprint process.
Before the inventors' discovery, uniform DEEs were used along a
side of an imprint field resulting in a DEZ having a uniform width.
The distances for DEEs may be made uniformly larger or uniformly
smaller; however, such alternatives have other consequences. To
minimize extrusions at the edge center regions, larger DEEs, an
earlier cure of the formable material, or both can be used, but
such a change may significantly increase a risk of having more
non-fill defects in the corner areas because those areas may not
have had sufficient time for adequate droplet spreading and
filling. If smaller DEEs, waiting for more filling to occur in the
corner areas, or both are used, such a change may significantly
increase the risk of more extrusion defects at the edge center
regions.
[0057] The inventors have discovered that a fluid droplet pattern
can use variable DEEs resulting in a DEZ that is indented farther
into the imprint field closer to a centerpoint along a side of the
imprint field. Thus, a portion of DEZ is wider and the distances
for the corresponding DEEs are longer near the centerpoint of the
side of the imprint field, as compared to another portion of the
DEZ and corresponding DEEs farther from the centerpoint. The
pattern helps to flow fluid droplets of a formable material 34, so
that the formable material 34 reaches all points of the template 18
along a side of the imprint field closer in time as compared to one
another without significantly increasing the risk of forming an
extrusion defect.
[0058] In essence, when using variable DEEs, the fluid droplet
placement better synchronizes the spreading/filling along the
entirety of the field edge (from center edge outward to corners) as
compared to droplet pattern having a uniform width of the DEZ and
uniform distances for the DEEs along the side of the imprint field.
Thus, a variable DEE approach, when used with a center-to-perimeter
template-substrate contact scheme, provides for a better balance of
extrusion control (near the centers of the field edges) vs.
non-fill control (at the field corners).
[0059] FIG. 2 illustrates a portion of a fluid droplet pattern 300.
The fluid droplet pattern 300 of fluid droplets 302 of the formable
material 34 is disposed within an imprint field. The imprint field
has a side 340 and a DEZ along the side 340. In an embodiment, the
fluid droplet pattern 300 is organized in rows, and each row
includes a terminal fluid droplet along a boundary of the DEZ. The
rows of the fluid droplet pattern 300 extend in a translating
direction, which is the direction in which the substrate 12 and the
template 18 move relative to each other. Fluid droplets 302 are
dispensed in the translating direction at a translating fluid
droplet pitch. As used in this specification, the translating
direction is referred as the x-direction, and the translating fluid
droplet pitch is an X-direction pitch.
[0060] The DEZ is the area between the side 340 and the dashed line
320 that passes though the terminal fluid droplets, including
terminal fluid droplets 322, 324, and 326. For the fluid droplet
pattern 300 illustrated in FIG. 2, the terminal fluid droplets 322,
324, and 326 have corresponding DEEs 362, 364, and 366,
respectively. The DEZ is narrower farther from the center of the
side 340 and wider closer to the center of the side 340. The DEE
364 corresponding to the terminal fluid droplet 324 is greater than
each of the DEEs 362 and 366 corresponding to the terminal fluid
droplets 322 and 326. The difference between the DEE 364 and each
of the DEEs 362 and 366 is less than the translating direction
(x-direction) pitch. In another embodiment, the difference between
the DEE 364 and each of the DEEs 362 and 366 may be the same or
greater than the translating direction (x-direction) pitch.
[0061] As will be described in more detail later in this
specification, the fluid droplet pattern 300 can be formed by
rotating a fluid dispenser, a substrate, or both. In an embodiment,
the rotation may be performed so that it is at most the same as the
x-direction pitch. For example, the fluid droplet pattern 300
corresponds to a rotational angle of 2 milliradians (mrads) when
the distance between the centers of the fluid droplets 322 and 326
is approximately 33 mm. The DEE 364 is 210 microns, and the DEEs
362 and 366 are 175 microns. Thus, the difference in DEEs is 35
microns in this particular embodiment.
[0062] FIG. 3 illustrates a portion of a fluid droplet pattern 400
and a corresponding set of photographs of a resist layer as seen
through the imprint template 18. The fluid droplet pattern 400 of
fluid droplets 402 of the formable material 34 is disposed within
an imprint field. The imprint field has a side 440 and a DEZ along
the side 440. In an embodiment, the fluid droplet pattern 400 is
organized in rows, and each row includes a terminal fluid droplet
along a boundary of the DEZ. The rows of the fluid droplet pattern
400 extend in a translating direction, which is the direction in
which the substrate 12 and the template 18 move relative to each
other. Fluid droplets 402 are dispensed in the translating
direction at a translating fluid droplet pitch. As used in this
specification, the translating direction is referred as the
x-direction, and the translating fluid droplet pitch is an
X-direction pitch.
[0063] The DEZ is the region between the side 440 and the dashed
line 420 that passes through the terminal fluid droplets, including
terminal fluid droplets 422, 424, and 426. For the fluid droplet
pattern 400 illustrated in FIG. 3, the terminal fluid droplets 422,
424, and 426 have corresponding DEEs 462, 464, and 466,
respectively, that are uniform. Unlike FIG. 2, in FIG. 3, the DEZ
has a substantially uniform width along the side 440.
[0064] In FIG. 3, the fluid droplet pattern 400 corresponds to a
rotational angle of zero. In other words, the substrate and fluid
droplet dispenser(s) is (are) not rotated relative to each other.
The distances 462, 464, and 466 along the side 440 are all 180
microns. Thus, the differences in DEEs are zero.
[0065] The amount of rotation and indentation may depend on the
pattern of recessions and protrusions along the imprint surface 22
of the template 18. When imprinting using the fluid droplet
patterns 300 and 400, a camera or another visual tool may be used
to monitor how the fluid front is progressing from the center of
the imprint fields to the edges of the imprint fields.
Alternatively or in conjunction with the camera or visual tool
during imprinting, the formable material may be cured, and the
printed and inspected for the presence and location of non-fill
defects and extrusion defects. Ideally, there are not any non-fill
defects extrusion defects for a particular rotation, and such
rotation may be used. If there are extrusion defects at any of the
corners, non-fill defects near a centerpoints of the edges, or
both, the rotation may be adjusted to a lower value. Thus based
information gathered, the angle of rotation may be determined.
[0066] The indentation of the DEZ along sides of the imprint field
can be obtained using different equipment configurations and
techniques, some of which are described and illustrated herein.
After reading this specification, skilled artisans will appreciate
that other embodiments can be used without departing from the
concepts as described here. An exemplary fluid dispenser is
illustrated in FIG. 4 before addressing other aspects of the
equipment configurations and technique as illustrated in FIGS. 5 to
12. In FIGS. 5 to 12, not all fluid droplets are illustrated to aid
in understanding the concepts, and therefore, only those fluid
droplets near the sides are illustrated.
[0067] FIG. 4 includes a side view of a portion of a fluid
dispenser 500. The fluid dispenser 500 includes fluid dispense
ports 520 through which the formable material is dispensed. The
fluid dispense ports 520 are oriented along one or more lines that
are substantially parallel to the length of the fluid dispenser
500. Any one or more of the embodiments described below can use the
fluid dispenser 500.
[0068] FIG. 5 includes an illustration of a portion of a fluid
dispense pattern 600 in accordance with an embodiment in which
fluid dispensers 610 and 620 are rotated with respect to a side
640, and the fluid droplet pattern 600 is formed with a single
pass. Referring to FIG. 5, the fluid dispense system 32 includes
the fluid dispenser 610 and the fluid dispenser 620, and the fluid
dispensers 610 and 620 are oriented in different rotational
directions with respect to the side 640 of the imprint field. In a
particular embodiment, the fluid dispenser 610 is rotated
counterclockwise with respect to the side 640, and the fluid
dispenser 620 is rotated clockwise with respect to the side 640.
The fluid dispensers 610 and 620 rotate with small positive and
small negative angles relative to the side 640 of the imprint
field, and the fluid droplet pattern 600 can be achieved with a
single pass as shown in FIG. 5. In the embodiment as illustrated,
the dispensers 610 and 620 remain at substantially the same
relative angle during a single pass. The upper left and lower right
quadrants of fluid droplets are formed using the fluid dispenser
610, and the lower left and upper right quadrants of fluid droplets
are formed using the fluid dispenser 620.
[0069] FIG. 6 includes an illustration of a portion of a fluid
dispense pattern 700 in accordance with an embodiment in which the
fluid dispense system 32 includes a fluid dispenser 710 that is
rotated one way relative to the side 740 for one pass and rotated
the other way to the side 730 for the other pass. The angle of
rotation may or may not be the same. Relative to the side 740, the
fluid dispenser 710 rotates clockwise in a positive angle in the
first pass, and rotates counterclockwise in a negative angle in the
second pass to form the fluid droplet pattern 700. In particular,
fluid droplets in the lower left and upper right quadrants are
formed during one pass, the angle of rotation of the fluid
dispenser is changed, and then fluid droplets in the lower right
and upper left quadrants are formed during the other pass.
[0070] FIG. 7 has an equipment configuration similar to FIG. 6.
FIG. 7 can be useful when all sides, rather than just two opposing
sides, have indentations for the DEZs. In the embodiment
illustrated in FIG. 7, the substrate 12, rather than the fluid
dispenser 810, is rotated when generating the fluid droplet pattern
800. The fluid dispenser 810 remains fixed (no rotation) during two
different passes, where the substrate 12 rotates in small positive
and negative angles between the two different passes.
[0071] FIG. 8 includes an illustration of a more complex equipment
configuration in which different fluid dispensers 910 and 920 that
extend along lengths that are oriented along adjacent sides of the
imprint field 900. The fluid dispenser 910 is positioned along one
side of the imprint field perpendicular to the dispense scan
direction (X-direction) and forms fluid droplets 912 during one
scan. The fluid dispenser 920 is positioned along another side of
the imprint field and forms fluid droplets 922 during another scan.
Lengths of the fluid dispensers 910 and 920 are along lines that
intersect at an angle other than 90.degree.. The substrate is
rotated with respect to both fluid dispensers 910 and 920. In other
words, the lengths of the fluid dispensers 910 and 920 are not
parallel with their corresponding sides.
[0072] In one or more of the previous embodiments, portions of the
fluid droplet pattern may be stitched together to keep the fluid
droplet pitch more uniform in the translating direction. The
embodiment illustrated in FIG. 9 can be formed similar to the
embodiment as described with respect to FIG. 5. FIG. 9 illustrates
the fluid dispensers 1010 and 1020 as previously described and
includes a fluid droplet pattern 1000 for an imprint field having
fluid droplets from different quadrants stitched together in
accordance with an embodiment. The two quadrants of fluid droplet
along the upper side and the two quadrants of fluid droplet along
the lower side are relatively close to each other near the center
of the fluid droplet pattern 1000. Without stitching, significant
gaps between the fluid droplet quadrants along the upper and lower
sides may occur. On an intra-row basis, stitching allows the fluid
droplets along a row to have spacings more consistent with the
fluid droplet pitch and have a predetermined local volume of the
formable material. Stitching can be useful when more than one fluid
dispenser or more than one pass is used to generate a fluid droplet
pattern.
[0073] In prior embodiments, the fluid dispenser, the substrate, or
both can be rotated in an X-Y plane. In such embodiments, the
spacing between the fluid dispenser and substrate is substantially
uniform. In further embodiments, the fluid dispenser, the
substrate, or both may be rotated in a Y-Z plane, such that the
spacing between the fluid dispenser and substrate vary along the
length of the fluid dispense. For example, one end of the fluid
dispenser may be closer to the substrate as compared to the other
end of the fluid dispenser. The spacing may become progressively
larger as the distance from the one end to the other end increases.
The dispenser, the substrate or both may pivot about a centerline
that is substantially perpendicular to the length of the fluid
dispenser or may pivot about a point at or closer to an end of the
fluid dispenser. In FIGS. 10 to 12, no rotation in the X-Y plane is
required. The lengths of the fluid dispensers can be substantially
parallel to the sides of the imprint fields.
[0074] FIG. 10 includes an illustration of an imprint field 1100
during the formation of a fluid droplet pattern. In FIG. 10, a
single fluid dispenser 1160 can be used with different rotations
during different passes. During a first pass, the fluid dispenser
1160 and the substrate are oriented such that a location 1162
represents a farther distance between the fluid dispenser 1160 and
the substrate, and a location 1164 represents a closer distance
between the fluid dispenser 1160 and the substrate. During the
first pass, sets 1102 and 1104 of fluid droplets are dispensed onto
the substrate within the imprint field 1100. After the first pass,
the orientation remains the same, such that the location 1162
represents a farther distance between the fluid dispenser 1160 and
the substrate, and the location 1164 represents a closer distance
between the fluid dispenser 1160 and the substrate. During a second
pass, sets 1106 and 1108 of fluid droplets are dispensed onto the
substrate within the imprint field 1100. Thus, FIG. 10 illustrates
another method of achieving the fluid droplet pattern as
illustrated in FIG. 9.
[0075] FIG. 11 includes an illustration of an imprint field 1200
during the formation of a fluid droplet pattern. In FIG. 11, a
single fluid dispenser 1260 can be used with rotation occurring
during each passes. At the beginning of a first pass, the fluid
dispenser 1260 and the substrate are oriented such that a location
1262 represents a farther distance between the fluid dispenser 1260
and the substrate, and a location 1264 represents a closer distance
between the fluid dispenser 1260 and the substrate. During the
first pass, the dispenser 1260 is rotated about an axis illustrated
by a dashed line. At the end of the first pass, the fluid dispenser
1260 and the substrate are oriented such that a location 1266
represents a closer distance between the fluid dispenser 1260 and
the substrate, and a location 1268 represents a farther distance
between the fluid dispenser 1260 and the substrate. A set 1202 of
fluid droplets is dispensed onto the substrate within the imprint
field 1200. During a second pass, the rotation is reversed. At the
beginning of the second pass, the fluid dispenser 1260 and the
substrate are oriented such that a location 1282 represents a
closer distance between the fluid dispenser 1260 and the substrate,
and a location 1284 represents a farther distance between the fluid
dispenser 1260 and the substrate. During the second pass, the
dispenser 1260 is rotated about the axis illustrated by the dashed
line. At the end of the second pass, the fluid dispenser 1260 and
the substrate are oriented such that a location 1286 represents a
farther distance between the fluid dispenser 1260 and the
substrate, and a location 1288 represents a closer distance between
the fluid dispenser 1260 and the substrate. A set 1206 of fluid
droplets is dispensed onto the substrate within the imprint field
1200.
[0076] FIG. 12 includes an illustration of an imprint field 1300
during the formation of a fluid droplet pattern. In FIG. 12, a pair
of fluid dispensers 1320 and 1340 can be rotated to form the fluid
droplet pattern in a single pass. At the beginning of the pass, the
fluid dispenser 1320 and the substrate are oriented such that a
location 1322 represents a closer distance between the fluid
dispenser 1320 and the substrate, and a location 1324 represents a
farther distance between the fluid dispenser 1320 and the
substrate; and the fluid dispenser 1340 and the substrate are
oriented such that a location 1346 represents a closer distance
between the fluid dispenser 1320 and the substrate, and a location
1348 represents a farther distance between the fluid dispenser 1340
and the substrate. In FIG. 12, a set 1302 of fluid droplets is
dispensed onto the substrate by the dispenser 1320 using ports
closer to the location 1322, a set 1304 of fluid droplets is
dispensed onto the substrate by the dispenser 1320 using ports
closer to the location 1324, a set 1306 of fluid droplets is
dispensed onto the substrate by the dispenser 1340 using ports
closer to the location 1346, a set 1308 of fluid droplets is
dispensed onto the substrate by the dispenser 1340 using ports
closer to the location 1348. Thus, FIG. 12 illustrates another
method of achieving the fluid droplet pattern as illustrated in
FIG. 9.
[0077] In accordance with an embodiment described herein, FIG. 13
includes a flow chart for a method that can be used forming a
substrate fluid droplet pattern for an imprint lithography process.
The method is better understood with respect to the apparatus 10 in
FIG. 1 and fluid dispenser and substrate orientations previously
described. The method can include providing a fluid dispenser
including a set of fluid dispense ports, at block 1402. In an
embodiment, the method can be performed by an imprint lithography
apparatus including a fluid dispense system, a stage, and a logic
element.
[0078] The method can further include generating a fluid droplet
pattern of fluid droplets of a formable material, at block 1422. At
this point in the process, the fluid droplet pattern can be virtual
pattern generated by the logic element. The logic element can
include hardware, firmware, software, or any combination thereof to
perform many of the operations described herein. In a particular
embodiment, the logic element can be the processor 54. The fluid
droplet pattern can be any of the patterns as previously described.
The logic element may use a hardware and processing description of
the apparatus 10 when determining the fluid droplet pattern. The
hardware and processing description can include the number of fluid
dispensers; when there are at least two fluid dispensers, the
positions of the fluid dispensers relative to each other and the
substrate; whether the one or more fluid dispensers or the
substrate is rotated; the number of passes used to generate the
fluid dispense pattern; the direction of motion of the substrate
and fluid dispensers relative to one another; whether any fluid
dispenser is rotated between passes; or the like.
[0079] A substrate can be placed on the stage, and in an
embodiment, the substrate can be a semiconductor wafer. The method
can further include moving the substrate and the set of the fluid
dispense ports relative to each other, at block 1424, and
dispensing fluid droplets of the formable material onto the
substrate, at block 1426. After the substrate and the set of the
fluid dispense ports start moving, the fluid droplets are dispensed
onto the substrate to achieve a physical instantiation of the fluid
droplet pattern corresponding to the virtual instantiation of the
fluid droplet pattern generated by the logic element. Referring to
FIG. 1, the processor can generate instructions that are
transmitted to the imprint head 30 and the fluid dispense system 32
potentially, and a stage controller (not illustrated). The fluid
dispense system can rotate the fluid dispenser or fluid dispenser,
control movement of the fluid dispenser, and control dispensing of
fluid droplets. The stage controller may rotate the substrate or
move the substrate along one or more directions. After reading this
specification, skilled artisans will appreciate that rotation and
movement during a pass may achieved by moving the fluid dispenser,
the substrate, or both the fluid dispenser and the substrate.
[0080] At block 1442, the method can include contacting the
formable material with the template. Referring to FIG.1, the
imprint head 30, the stage 16, or both the imprint head 30 and the
stage 16 vary a distance between the mold 20 and the substrate 12
to define a desired volume therebetween that is filled by the
formable material 34. For example, the imprint head 30 can apply a
force to the template 18, such that the mold 20 contacts the
formable material 34 on the substrate 12. In an embodiment, the
patterned surface has projections and recessions, and in another
embodiment, the patterned surface can be a blank (a flat surface
without any projections or recessions). The fluid droplet pattern
allows the formable material to reach its desired locations more
quickly along the sides of the imprint field without a significant
risk of forming an extrusion defect.
[0081] At block 1444, the method includes curing the formable
material to form a patterned layer corresponding to the pattern
surface of the template. Curing can be performed by exposure to
electromagnetic radiation. In an embodiment, the electromagnetic
radiation can be ultraviolet radiation. In another embodiment, the
formable material can be cured using heat. The patterned layer on
the substrate has a complementary pattern as compared to the
patterned surface of the template. Projections along the patterned
layer correspond to recessions in the patterned surface of the
template, and recessions in the patterned layer correspond to
projections along the patterned surface of the template. The
recessions in the patterned layer are parts of a residual layer
having a residual layer thickness.
[0082] The methods can be useful in manufacturing an article that
includes a substrate, such as an electronic component that includes
part of a semiconductor wafer.
[0083] Many operations have been described with respect to
particular components within the apparatus 10. In particular
embodiment, operations performed by a logic element, which may be
at least a part of the processor 54, may be performed by other
components within the apparatus 10 or split between the processor
54 and such other components. For example, some operations
previously described as being performed by the processor 54 may be
performed by a stage controller that controls the operation of the
stage 16, the fluid dispense system 32, a fluid dispenser
controller that controls fluid dispenser. Furthermore, information
can be transmitted in order to carry out the actions described
herein. The information can be in the form of instructions to be
executed, signals, pulses, or the like. The stage 16, the fluid
dispense system 32, or both may include a controller that can act
on instructions received from the processor 54. In another
embodiment, the stage 16 or the fluid dispense system 32 may
respond to analog signals received. For example, the information
can be a particular direct current voltage or a light pulse. After
reading this specification, skilled artisans will be able to
configure an imprint lithography apparatus 10 to meet the needs or
desires in view of the equipment within the apparatus 10. Thus, the
description of the embodiments does not limit the scope of the
present invention.
[0084] Embodiments of the apparatuses and method can be useful in
filling an imprint field relatively quickly without extrusion
defects or other complications. A virtual fluid droplet pattern can
be generated by a logic element, such as a processor within a
lithographic tool, to tailor the shape of the DEZ for a particular
imprint surface of a template. Instructions corresponding to the
virtual patterned can provided to a fluid dispense system in
forming an actual fluid droplet pattern. The fluid droplet pattern
can allow a formable material to reach points along sides of an
imprint closer in time as compared to conventional techniques. The
indentations of the patterns along sides help to keep the
likelihood of forming an extrusion defect significantly low.
[0085] Note that not all of the activities described above in the
general description or the examples are required, that a portion of
a specific activity may not be required, and that one or more
further activities may be performed in addition to those described.
Still further, the order in which activities are listed is not
necessarily the order in which they are performed.
[0086] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any feature(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature of any or all the claims.
[0087] The specification and illustrations of the embodiments
described herein are intended to provide a general understanding of
the structure of the various embodiments. The specification and
illustrations are not intended to serve as an exhaustive and
comprehensive description of all of the elements and features of
apparatus and systems that use the structures or methods described
herein. Separate embodiments may also be provided in combination in
a single embodiment, and conversely, various features that are, for
brevity, described in the context of a single embodiment, may also
be provided separately or in any subcombination. Further, reference
to values stated in ranges includes each and every value within
that range. Many other embodiments may be apparent to skilled
artisans only after reading this specification. Other embodiments
may be used and derived from the disclosure, such that a structural
substitution, logical substitution, or another change may be made
without departing from the scope of the disclosure. Accordingly,
the disclosure is to be regarded as illustrative rather than
restrictive.
* * * * *