U.S. patent application number 13/923401 was filed with the patent office on 2014-12-25 for patterning for selective area deposition.
The applicant listed for this patent is Carolyn R. Ellinger, Shelby F. Nelson, Kurt D. Sieber. Invention is credited to Carolyn R. Ellinger, Shelby F. Nelson, Kurt D. Sieber.
Application Number | 20140377963 13/923401 |
Document ID | / |
Family ID | 52111272 |
Filed Date | 2014-12-25 |
United States Patent
Application |
20140377963 |
Kind Code |
A1 |
Ellinger; Carolyn R. ; et
al. |
December 25, 2014 |
PATTERNING FOR SELECTIVE AREA DEPOSITION
Abstract
A method of producing a patterned inorganic thin film element
includes providing a substrate. A thin layer of polymeric inhibitor
is uniformly depositing on the substrate. A patterned mask having
open areas is provided on the thin layer of polymeric inhibitor.
The thin layer of polymeric inhibitor is patterned by removing
inhibitor from areas exposed by the open areas of the patterned
mask using a highly reactive oxygen process. An inorganic thin film
layer is deposited on the substrate in the areas exposed by the
removal of the thin layer of polymeric inhibitor using an atomic
layer deposition process.
Inventors: |
Ellinger; Carolyn R.;
(Rochester, NY) ; Nelson; Shelby F.; (Pittsford,
NY) ; Sieber; Kurt D.; (Rochester, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ellinger; Carolyn R.
Nelson; Shelby F.
Sieber; Kurt D. |
Rochester
Pittsford
Rochester |
NY
NY
NY |
US
US
US |
|
|
Family ID: |
52111272 |
Appl. No.: |
13/923401 |
Filed: |
June 21, 2013 |
Current U.S.
Class: |
438/763 |
Current CPC
Class: |
H01L 21/02554 20130101;
H01L 21/02579 20130101; C23C 16/042 20130101; H01L 21/02422
20130101; C23C 16/407 20130101; C23C 16/45551 20130101; H01L
21/31138 20130101; H01L 21/0228 20130101; H01L 21/32 20130101; H01L
21/02576 20130101; C23C 16/403 20130101; H01L 21/02642
20130101 |
Class at
Publication: |
438/763 |
International
Class: |
H01L 21/02 20060101
H01L021/02 |
Claims
1. A method of producing a patterned thin film element comprising:
providing a substrate; providing a polymeric inhibitor that retains
its ability to inhibit atomic layer deposition after exposure to a
highly reactive oxygen process; depositing a thin layer of the
polymeric inhibitor on the substrate; providing a patterned mask
having open areas on the thin layer of the polymeric inhibitor;
patterning the thin layer of the polymeric inhibitor by removing
inhibitor from areas exposed by the open areas of the patterned
mask using a highly reactive oxygen process; depositing an
inorganic thin film layer on the substrate only in areas exposed by
the removal of the thin layer of the polymeric inhibitor using an
atomic layer deposition process to form a patterned inorganic thin
film layer on the substrate; removing the printed patterned mask
after exposure to the highly reactive oxygen process; and exposing
the patterned thin layer of the polymeric inhibitor to a second
highly reactive oxygen process after the printed pattern mask is
removed, wherein providing the patterned mask includes printing the
patterned mask on the thin layer of the polymeric inhibitor.
2.-3. (canceled)
4. The method of claim 1, wherein printing the patterned mask
includes using a flexographic, inkjet, gravure, offset lithography,
microcontact printing, or screen printing process.
5. The method of claim 4, wherein printing the patterned mask
includes using an ink including a polymer.
6. The method of claim 1, wherein the patterned mask is a patterned
thin layer of polymeric mask material that is different when
compared to the thin layer of the polymeric inhibitor.
7. The method of claim 6, wherein patterning the thin layer of the
polymeric inhibitor by removing inhibitor from areas exposed by the
open areas of the patterned mask using the highly reactive oxygen
process also removes the patterned thin layer of polymeric mask
material.
8. The method of claim 7, wherein a portion of the thin layer of
the polymeric inhibitor that was originally under the polymeric
mask material also is removed during the exposure to the highly
reactive oxygen process.
9. The method of claim 1, wherein the highly reactive oxygen
process is an oxygen plasma.
10. The method of claim 1, wherein the highly reactive oxygen
process is an UV-ozone process.
11.-12. (canceled)
13. The method of claim 1, wherein the thin layer of the polymeric
inhibitor includes a solvent-soluble polymer.
14. The method of claim 13, wherein the solvent-soluble polymer has
a molecular weight greater than 10000.
15. The method of claim 13, wherein the thin layer of the polymeric
inhibitor includes an acrylate.
16. The method of claim 15, wherein the thin layer of the polymeric
inhibitor includes polymethylmethacrylate (PMMA).
17. The method of claim 1, further including removing the thin
layer of the polymeric inhibitor after depositing the inorganic
thin film layer.
18. A method of producing a patterned thin film element comprising:
providing a substrate; depositing a thin layer of polymeric
inhibitor on the substrate; providing a patterned mask having open
areas on the thin layer of polymeric inhibitor; patterning the thin
layer of polymeric inhibitor by removing inhibitor from areas
exposed by the open areas of the patterned mask using a highly
reactive oxygen process; depositing a first inorganic thin film
layer on the substrate in areas exposed by the removal of the thin
layer of polymeric inhibitor using an atomic layer deposition
process to form a patterned inorganic thin film layer on the
substrate; and depositing a second inorganic thin film layer on the
first inorganic thin film layer in areas not containing the thin
layer of polymeric inhibitor using an atomic layer deposition
process to form a patterned second inorganic thin film layer on the
first inorganic thin film layer.
19. The method of claim 18, further comprising exposing the first
inorganic thin film layer and the thin polymeric inhibitor layer to
a highly reactive oxygen process prior to depositing the second
inorganic thin film.
20. The method of claim 18, wherein the thin layer of the polymeric
inhibitor includes polymethylmethacrylate (PMMA).
21. The method of claim 20, wherein the highly reactive oxygen
process is one of an oxygen plasma and an UV-ozone process.
22. The method of claim 20, wherein providing the patterned mask
includes one of printing the patterned mask on the thin layer of
polymeric inhibitor and placing a shadow mask on the thin layer of
polymeric inhibitor.
23. The method of claim 1, wherein the thin layer of the polymeric
inhibitor includes polymethylmethacrylate (PMMA).
24. The method of claim 23, wherein the highly reactive oxygen
process is one of an oxygen plasma and an UV-ozone process.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Reference is made to commonly-assigned, U.S. patent
application Ser. No. ______ (Docket K001548), entitled "SUBSTRATE
PREPARATION FOR SELECTIVE AREA DEPOSITION", filed concurrently
herewith.
FIELD OF THE INVENTION
[0002] This invention relates generally to patterned thin film
fabrication and electronic and optoelectronic devices including
patterned thin films. In particular, this invention relates to
selective area deposition of materials including, for example,
metal-oxides and devices including, for example, thin film
transistors and photovoltaics produced using this fabrication
technique.
BACKGROUND OF THE INVENTION
[0003] Modern-day electronics require multiple patterned layers of
electrically or optically active materials, sometimes over a
relatively large substrate. Electronics such as radio frequency
identification (RFID) tags, photovoltaics, optical and chemical
sensors all require some level of patterning in their electronic
circuitry. Flat panel displays, such as liquid crystal displays or
electroluminescent displays (for example, OLED), rely upon
accurately patterned sequential layers to form thin film components
of the backplane. These components include capacitors, transistors,
and power buses. The industry is continually looking for new
methods of materials deposition and layer patterning for both
performance gains and cost reductions. Thin film transistors (TFTs)
may be viewed as representative of the electronic and manufacturing
issues for many thin film components. TFTs are widely used as
switching elements in electronics, for example, in active-matrix
liquid-crystal displays, smart cards, and a variety of other
electronic devices and components thereof.
[0004] There is a growing interest in depositing thin film
semiconductors on plastic or flexible substrates, particularly
because these supports are more mechanically robust, lighter
weight, and allow more economic manufacturing, for example, by
allowing roll-to-roll processing. Plastics, however, typically
limit device processing to below 200.degree. C. There are other
many issues associated with plastic supports when using traditional
photolithography during conventional manufacturing, making it
difficult to perform alignments of transistor components across
typical substrate widths up to one meter or more. Traditional
photolithographic processes and equipment may be seriously impacted
by the substrate's maximum process temperature, solvent resistance,
dimensional stability, water, and solvent swelling, all key
parameters in which plastic supports are typically inferior to
glass.
[0005] The discovery of practical inorganic semiconductors as a
replacement for current silicon-based technologies has also been
the subject of considerable research efforts. For example, metal
oxide semiconductors are known that constitute zinc oxide, indium
oxide, gallium indium zinc oxide, tin oxide, or cadmium oxide
deposited with or without additional doping elements including
metals such as aluminum. Such semiconductor materials, which are
transparent, can have an additional advantage for certain
applications, as discussed below. Additionally, metal oxide
dielectrics such as alumina (Al.sub.2O.sub.3) and TiO.sub.2 are
useful in practical electronics applications as well as optical
applications such as interference filters. Dielectric materials
that are easily processable and patternable are also important to
the success of low cost and flexible electronic devices. In
addition, metal oxide materials can serve as barrier or
encapsulation elements in various electronic devices. These
materials also require patterning so that a connection can be made
to the encapsulated devices.
[0006] Atomic layer deposition (ALD) can be used as a fabrication
step for forming a number of types of thin-film electronic devices,
including semiconductor devices and supporting electronic
components such as resistors and capacitors, insulators, bus lines,
and other conductive structures. ALD is particularly suited for
forming thin layers of metal oxides in the components of electronic
devices. General classes of functional materials that can be
deposited with ALD include conductors, dielectrics or insulators,
and semiconductors. Examples of useful semiconducting materials are
compound semiconductors such as gallium arsenide, gallium nitride,
cadmium sulfide, zinc oxide, and zinc sulfide.
[0007] A number of device structures can be made with the
functional layers described above. A capacitor results from placing
a dielectric between two conductors. A diode results from placing
two semiconductors of complementary carrier type between two
conducting electrodes. There may also be disposed between the
semiconductors of complementary carrier type a semiconductor region
that is intrinsic, indicating that that region has low numbers of
free charge carriers. A diode may also be constructed by placing a
single semiconductor between two conductors, where one of the
conductor/semiconductors interfaces produces a Schottky barrier
that impedes current flow strongly in one direction. A transistor
results from placing upon a conductor (the gate) an insulating
layer followed by a semiconducting layer. If two or more additional
conductor electrodes (source and drain) are placed spaced apart in
contact with the top semiconductor layer, a transistor can be
formed. Any of the above devices can be created in various
configurations as long as the critical interfaces are created.
[0008] Advantageously, ALD steps are self-terminating and can
deposit precisely one atomic layer when conducted up to or beyond
self-termination exposure times. An atomic layer typically ranges
from about 0.1 to about 0.5 molecular monolayers, with typical
dimensions on the order of no more than a few Angstroms. In ALD,
deposition of an atomic layer is the outcome of a chemical reaction
between a reactive molecular precursor and the substrate. In each
separate ALD reaction-deposition step, the net reaction deposits
the desired atomic layer and substantially eliminates "extra" atoms
originally included in the molecular precursor. In its most pure
form, ALD involves the adsorption and reaction of each of the
precursors in the complete absence of the other precursor or
precursors of the reaction. In practice, as in any process, it is
difficult to avoid some direct reaction of the different precursors
leading to a small amount of chemical vapor deposition reaction.
The goal of any process claiming to perform ALD is to obtain device
performance and attributes commensurate with an ALD process while
recognizing that a small amount of CVD reaction can be
tolerated.
[0009] In ALD processes, typically two molecular precursors are
introduced into the ALD reactor in separate stages. U.S. Patent
Application Publication 2005/0084610 (Selitser) discloses an
atmospheric pressure atomic layer chemical vapor deposition process
that involve separate chambers for each stage of the process and a
series of separated injectors are spaced around a rotating circular
substrate holder track. A spatially dependent ALD process can be
accomplished using one or more of the systems or methods described
in more detail in WO 2008/082472 (Cok), U.S. Patent Application
Publications 2008/0166880 (Levy), 2009/0130858 (Levy), 2009/0078204
(Kerr et al.), 2009/0051749 (Baker), 2009/0081366 (Kerr et al.),
and U.S. Pat. No. 7,413,982 (Levy), U.S. Pat. No. 7,456,429 (Levy),
and U.S. Pat. No. 7,789,961 (Nelson et al.), U.S. Pat. No.
7,572,686 (Levy et al.), all of which are hereby incorporated by
reference in their entirety.
[0010] There is growing interest in combining ALD with a technology
known as selective area deposition (SAD). As the name implies,
selective area deposition involves treating portion(s) of a
substrate such that a material is deposited only in those areas
that are desired, or selected. Sinha et al. (J. Vac. Sci. Technol.
B 24 6 2523-2532 (2006)), have remarked that selective area ALD
requires that designated areas of a surface be masked or
"protected" to prevent ALD reactions in those selected areas, thus
ensuring that the ALD film nucleates and grows only on the desired
unmasked regions. It is also possible to have SAD processes where
the selected areas of the surface area are "activated" or surface
modified in such a way that the film is deposited only on the
activated areas. There are many potential advantages to selective
area deposition techniques, such as eliminating an etch process for
film patterning, reduction in the number of cleaning steps
required, and patterning of materials which are difficult to etch.
One approach to combining patterning and depositing the
semiconductor is shown in U.S. Pat. No. 7,160,819 entitled "METHOD
TO PERFORM SELECTIVE ATOMIC LAYER DEPOSTION OF ZINC OXIDE" by
Conley et al. Conley et al. discuss materials for use in patterning
Zinc Oxide on silicon wafers. No information is provided, however,
on the use of other substrates, or the results for other metal
oxides.
[0011] SAD work to date has focused on the problem of patterning a
single material during deposition. There persists a problem of
combining multiple SAD steps to form working devices. Processes for
building complete devices need to be able to control the properties
the critical interfaces, particularly in field effect devices like
TFTs.
[0012] While there are reasonable water soluble polymeric
inhibitors, the best polymeric inhibitors found to date are solvent
soluble. In order to pattern these solvent soluble polymers,
typically photolithographic processes are used which require
exposure through a fixed mask. Photolithographic processes can
leave residue on the surface which can inhibit growth on unintended
areas of the substrate. Additional, by its nature, photolithography
is not a digital process. Although there are printing processes
that work with solvent solutions, it is preferable to work with
solutions that are aqueous and therefore less harmful to the
environment. For both ease of manufacture and for digital pattern
control, it is desirable to be able to pattern by printing. There
remains a need for novel processes to improve the robustness of
photolithographically defined SAD and for novel digital processes
to pattern solvent soluble polymeric materials.
SUMMARY OF THE INVENTION
[0013] In the present invention, selective area deposition of metal
oxides or other materials is used in a process that uses a
spatially dependent atomic layer deposition. Advantageously, the
present invention is adaptable for deposition on a web or other
moving substrate including deposition on large area substrates.
[0014] According to an aspect of the invention, a method of
producing a patterned inorganic thin film element includes
providing a substrate. A thin layer of polymeric inhibitor is
uniformly deposited on the substrate. A patterned mask having open
areas is provided on the thin layer of polymeric inhibitor. The
thin layer of polymeric inhibitor is patterned by removing
inhibitor from areas exposed by the open areas of the patterned
mask using a highly reactive oxygen process. An inorganic thin film
layer is deposited on the substrate in the areas exposed by the
removal of the thin layer of polymeric inhibitor using an atomic
layer deposition process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the detailed description of the example embodiments of
the invention presented below, reference is made to the
accompanying drawings, in which:
[0016] FIG. 1 is a flow chart describing the steps of one
embodiment of the present process for forming a patterned inorganic
layer;
[0017] FIG. 2 is a flow chart describing the steps of an alternate
embodiment of the present process for forming a patterned inorganic
layer;
[0018] FIG. 3 is a flow chart describing the steps of another
embodiment of the present process for forming a patterned inorganic
layer;
[0019] FIG. 4 is a flow chart describing the steps of another
embodiment of the present process for forming a patterned inorganic
multi-layer stack;
[0020] FIGS. 5a through 5g are cross-sectional side views of one
embodiment of the present process of forming the patterned
inorganic layer as shown in FIG. 5g;
[0021] FIGS. 6a through 6f are cross-sectional side views of one
embodiment of the present process of forming the patterned
inorganic layer as shown in FIG. 6f;
[0022] FIGS. 7a through 7d are cross-sectional side views of one
embodiment of the present process of forming the patterned
inorganic layer as shown in FIG. 7d;
[0023] FIGS. 8a through 8g are cross-sectional side views of one
embodiment of the present process of forming the patterned
multi-layer inorganic stack as shown in FIG. 8g;
[0024] FIGS. 9a through 9f are cross-sectional side views of one
embodiment of the present process of forming the patterned
multi-layer inorganic stack as shown in FIG. 9f;
[0025] FIG. 10 is a cross-sectional side view of a deposition
device, used in an exemplified process, showing the arrangement of
gaseous materials provided to a substrate that is subject to the
thin film deposition process of the Examples; and
[0026] FIG. 11 is a cross-sectional side view of a deposition
device, used in the process of FIG. 10, showing the arrangement of
gaseous materials provided to a substrate that is subject to the
thin film deposition process of the Examples.
DETAILED DESCRIPTION OF THE INVENTION
[0027] For the description that follows, the term "gas" or "gaseous
material" is used in a broad sense to encompass any of a range of
vaporized or gaseous elements, compounds, or materials. Other terms
used herein, such as: reactant, precursor, vacuum, and inert gas,
for example, all have their conventional meanings as would be well
understood by those skilled in the materials deposition art. The
figures provided are not drawn to scale but are intended to show
overall function and the structural arrangement of some embodiments
of the present invention.
[0028] The embodiments of the present invention all relate to thin
film inorganic materials and devices that contain them. Example
embodiments of the present invention use selective area deposition
(SAD) in combination with atomic layer deposition (ALD). SAD
employs a patterned material referred to as a "deposition inhibitor
material", "deposition inhibiting material", or simply an
"inhibitor" that inhibits the growth of a thin film material on the
substrate when the substrate is subjected to an atomic layer
deposition. By inhibiting the growth where the deposition inhibitor
material is present, the ALD process only deposits material in
regions (selective areas) of the substrate where the inhibitor is
not present. The phrase "deposition inhibitor material" and its
equivalents refer herein to any material on the substrate that
inhibits the deposition of material during atomic layer deposition
(ALD). The "deposition inhibitor material" includes the material
applied to the substrate as well as the material resulting from any
optionally subsequent crosslinking or other reaction that modifies
the material that can occur prior to depositing an inorganic thin
film on the substrate by atomic layer deposition. A polymeric
deposition inhibitor material can be crosslinked after applying the
polymer onto the substrate, before or during the pattering
step.
[0029] The polymer deposition inhibitor material can be a compound
or polymer that, after being applied, is subsequently polymerized,
crosslinked, or polymerized and crosslinked. Polymers are
preferably addition polymers such as, for example, a
poly(perfluoroalkyl methacrylate); poly(methyl methacrylate);
poly(cyclohexyl methacrylate); poly(benzyl methacrylate);
poly(iso-butylene); poly(9,9-dioctylfluorenyl-2,7-diyl);
poly(hexafluorobutyl methacrylate), and copolymers thereof, wherein
the alkyl has one to six carbon atoms.
[0030] Crosslinking can be used to insolubilize a polymeric
deposition inhibitor material after application onto the surface of
the substrate. The crosslinking can occur prior to or after
patterning.
[0031] In the present invention the deposition inhibiting material
layer is a thin film layer of a polymer. In order to use an
inhibitor in a manufacturing process it is desirable that the
polymer layer thickness be as thin as possible and still have
sufficient inhibition effectiveness. Here we define a thin film
layer of polymer inhibitor to mean any layer of polymeric inhibitor
under 5000 .ANG., preferably under 1000 .ANG. and in the most
preferred embodiments the layer thickness is under 500 .ANG..
[0032] The thin film polymer inhibitor layer can be formed from a
polymer that is in any convenient solvent and can have any useful
molecular weight, preferably in the range of 2,000 to 2,000,000. It
can include a single functional group, or can include a plurality
of functional groups. In the case of a plurality, the polymer can
be a random, periodic, or block polymer. For polymers with chiral
centers the polymer can be isotactic, syndiotactic, or atactic. The
polymer can have side chains and can be a graft copolymer. The
polymer may be linear or branched. The polymer may have low numbers
of free acid groups. Preferred polymers that are soluble in non
polar solvents are poly(methylmethcrylate), poly(carbonates),
poly(sulfones), and poly(esters). Polymers with chemical
modification are preferred, including polymers modified with
fluorine or fluorine containing compounds.
[0033] In some embodiments, the deposition inhibitor material is
chosen specifically for the material to be deposited. The
deposition inhibitor material has a given inhibition power. The
inhibition power is defined as the layer thickness at or below
which the deposition inhibitor material is effective. Preferably,
the deposition inhibitor material, during use, exhibits an
inhibition power of at least 50 .ANG., more preferably at least 100
.ANG., most preferably at least 300 .ANG..
[0034] Although solvent soluble polymers are difficult to print, it
is standard practice to deposit these polymers in uniform thin film
for photolithographic processing. In some embodiments, a uniform
layer of the polymeric deposition inhibitor material is deposited
and then patterned to form a patterned layer of the deposition
inhibitor material. The active polymer based inhibitor material can
be suspended or dissolved in a solvent or vehicle. The material can
include surfactants, stabilizers, or viscosity modifiers.
[0035] Providing the patterned mask layer on the deposition
inhibiting material layer can include placing a shadow mask in
contact with the polymeric deposition inhibitor or printing a
patterned mask layer on the inhibitor surface. The term "shadow
mask" as used herein has its common accepted meaning as a physical
mask having holes or openings which material can pass through. The
shadow mask can be made of any solid that can withstand the
patterning process including metal, glass, or polymer film.
Printing methods for the printed patterned mask layer include
inkjet printing, a flexographic printing, and gravure printing.
Other methods of providing the printed patterned mask layer include
microcontact printing, offset lithography, patch coating, screen
printing, or transfer from a donor sheet.
[0036] The printed pattern mask layer can be composed of a polymer
that is suspended or dissolved in a solvent or vehicle. The
material can include surfactants, stabilizers, or viscosity
modifiers. The printed material of the patterned mask layer can be
dried using natural convection, forced convection, or radiant heat.
The material can be treated to change its morphology or chemical
composition. A preferred chemical composition change is to
crosslink the material. The change in morphology or chemical
composition can be accomplished by exposure to a vapor phase or
liquid phase reactant, or treatment with heat or light. Preferred
processes include the crosslinking of material with UV light.
[0037] Polymers soluble in polar solvents such as water, alcohols,
or ketones are particularly preferred for the patterned mask layer.
Polymers may include amide groups, such as poly(amide),
poly(vinylpyrrolidone), and poly(2-ethyl-oxazoline). Polymers may
include ether linkages, such as poly(ethylene glycol). Polymers may
include alcohol functionalities, such as poly(vinyl alcohol).
Polymers may include neutralized acid groups such as sodium
poly(styrene sulfonate) and the sodium salt of poly(acrylic acid).
The polymer used in the printed patterned mask layer should be
suspended or dissolved in a solvent which the polymeric inhibitor
material is not soluble in.
[0038] In one embodiment of the present invention a polymer
inhibitor film is patterned by printing a patterned mask layer onto
the thin polymer film, and then removing the polymer film in the
areas where the mask material is not. The removal of the polymer
can be a highly reactive oxygen process. As used herein, highly
reactive oxygen processes include UV-ozone (UVO) and
oxygen-containing plasma processes. The UVO process uses short
wavelength UV (185 nm) light to generate ozone and longer
wavelength UV (253.7 nm) light to breakdown the bonds in the
polymer film. The longer wavelength UV light also reacts with the
ozone to form atomic oxygen. The atomic oxygen and the highly
active ozone react with the surface organics (and the reaction
by-products of the UV-polymer reaction) to form volatile molecules
that desorb from the surface. Oxygen plasmas have highly reactive
ions which interact with, or in some cases bombard, the polymer
surface, reacting with the organics to form volatile species. Some
plasma species, particularly in sub-atmospheric pressure plasmas,
have high kinetic energy which bombard the surface and can remove
material via a sputter-etch mechanism.
[0039] It is common practice to use these highly reactive oxygen
processes to clean substrates, and to transform normally
hydrophobic surfaces to hydrophilic surfaces by removing
contaminates and leaving oxygen containing functional groups
exposed on the surface. This transformation from hydrophobic to
hydrophilic typically changes the ability of a deposition inhibitor
to inhibit the ALD growth. It is desirable to have polymeric
inhibitors that are still functional as inhibitors after exposure
to highly reactive oxygen processes. In the present invention the
thin layer of polymeric inhibitor retains the ability to inhibit
inorganic film growth from ALD processes after exposure to a highly
reactive oxygen process. In one embodiment, the thin layer of
polymeric inhibitor is patterned by selectively removing areas of
the thin layer of polymeric inhibitor using a highly reactive
oxygen process. In another embodiment, the substrate surface is
cleaned using a highly reactive oxygen process prior to ALD, and
after the patterning of the deposition inhibitor.
[0040] When removing the inhibitor polymer, the mask layer can be
partially or fully removed. In embodiments where the mask layer is
completely removed, some amount of the underlying polymer inhibitor
layer can be removed leaving a thinner film of polymeric inhibitor
than was originally coated.
[0041] The process of making the thin inorganic films of the
present invention can be carried out at a support temperature of
about 300.degree. C., or more preferably below 250.degree. C. These
temperatures are well below traditional integrated circuit and
semiconductor processing temperatures, which enable the use of any
of a variety of relatively inexpensive supports, such as flexible
polymeric supports. Thus, the invention enables production of
relatively inexpensive circuits containing thin film transistors
with significantly improved performance.
[0042] The substrates used in the present invention can be any
material that acts as a mechanical support for the subsequently
coated layers. The substrate can include a rigid material such as
glass, silicon, or metals. Particularly useful metals are stainless
steel, steel, aluminum, nickel, and molybdenum. The substrate can
also include a flexible material such as a polymer film or paper
such as Teslin. Useful substrate materials include organic or
inorganic materials. For example, the substrate can include
inorganic glasses, ceramic foils, polymeric materials, filled
polymeric materials, coated metallic foils, acrylics, epoxies,
polyamides, polycarbonates, polyimides, polyketones,
poly(oxy-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylene)
(sometimes referred to as poly(ether ether ketone) or PEEK),
polynorbornenes, polyphenyleneoxides, poly(ethylene
naphthalenedicarboxylate) (PEN), poly(ethylene terephthalate)
(PET), poly(ether sulfone) (PES), poly(phenylene sulfide) (PPS),
and fiber-reinforced plastics (FRP). The thickness of substrate 110
can vary, typically from about 100 .mu.m to about 1 cm.
[0043] A flexible support or substrate can be used in the present
invention. Using a flexible substrate allows for roll processing,
which can be continuous, providing economy of scale and economy of
manufacturing over flat or rigid supports. The flexible support
chosen is preferably capable of wrapping around the circumference
of a cylinder of less than about 50 cm in diameter, more preferably
25 cm in diameter, and most preferably 10 cm in diameter, without
distorting or breaking, using low force as by unaided hands. The
preferred flexible support can be rolled upon itself. Additional
examples of flexible substrates include thin metal foils such as
stainless steel provided the foils are coated with an electrically
insulating material layer to electrically isolate any electric
components such as thin film transistors. Nominally rigid materials
that are flexible due to their thinness may also be used. These
include glass at thicknesses below 200 .mu.m and metals at
thicknesses below 500 .mu.m.
[0044] In some example embodiments, the substrate can include a
temporary support or support material layer, for example, when
additional structural support is desired for a temporary purpose,
e.g., manufacturing, transport, testing, or storage. In these
example embodiments, substrate can be detachably adhered or
mechanically affixed to the temporary support. For example, a
flexible polymeric support can be temporarily adhered to a rigid
glass support to provide added structural rigidity during the
transistor manufacturing process. The glass support can be removed
from the flexible polymeric support after completion of the
manufacturing process.
[0045] The substrate can be bare indicating that it contains no
substantial materials on its surface other the material from which
it is composed. The substrate can include various layers on the
surface. These layers include subbing layers, adhesion layers,
release layers, wetting layers, hydrophilic layers, and hydrophobic
layers. The substrate surface can be treated in order to promote
various properties. These treatments include plasma treatments,
corona discharge treatments, and chemical treatments.
[0046] The substrate can also include on its surface patterned
materials. These patterns can include patterns that modulate light
transmission or electrical conductivity within or on the substrate.
The patterns can include complete devices, circuits, or active
elements existing on the substrate. The patterns can include
portions of devices, circuits, or active elements awaiting
subsequent processing steps for completion.
[0047] Atomic Layer Deposition (ALD) is a process which is used to
produce coatings with thicknesses that can be considered
consistent, uniform, or even exact. ALD produces coatings that can
be considered conformal or even highly conformal material layers.
Generally described, an ALD process accomplishes substrate coating
by alternating between two or more reactive materials commonly
referred to as precursors, in a vacuum chamber. A first precursor
is applied to react with the substrate. The excess of the first
precursor is removed is removed from the vacuum chamber. A second
precursor is then applied to react with the first precursor on the
substrate. The excess of the second precursor is removed from the
vacuum chamber and the process is repeated.
[0048] Recently, a new ALD process has been developed which negates
the need for a vacuum chamber. This process, commonly referred to
as S-ALD, is described in at least one of U.S. Pat. No. 7,413,982,
U.S. Pat. No. 7,456,429, U.S. Pat. No. 7,789,961, and US
2009/0130858, the disclosures of which are incorporated by
reference herein. S-ALD produces coatings with thicknesses that can
be considered consistent, uniform, or even exact. S-ALD produces
coatings that can be considered conformal or even highly conformal
material layers. S-ALD is also compatible with a low temperature
coating environment. Additionally, S-ALD is compatible with web
coating, making it attractive for large scale production
operations. Even though some web coating operations may experience
alignment issues, for example, web tracking or stretching issues,
the architecture of the present invention reduces reliance on high
resolution or very fine alignment features during the manufacturing
process. As such, S-ALD is well suited for manufacturing the
present invention.
[0049] The preferred process of the present invention employs a
continuous spatially dependent ALD (as opposed to pulsed or time
dependent ALD) gaseous material distribution. The process of the
present invention allows operation at atmospheric or
near-atmospheric pressures and is capable of operating in an
unsealed or open-air environment. The process of the present
invention is adapted such that material is deposited only in
selected areas of a substrate.
[0050] Atomic layer deposition can be used in the present invention
to deposit a variety of inorganic thin films that are metals or
that comprise a metal-containing compound. Such metal-containing
compounds include, for example (with respect to the Periodic Table)
a Group V or Group VI anion. Such metal-containing compounds can,
for example, include oxides, nitrides, sulfides or phosphides of
zinc, aluminum, titanium, hafnium, zirconium or indium, or
combinations thereof.
[0051] Oxides that can be made using the process of the present
invention include, but are not limited to: zinc oxide (ZnO),
aluminum oxide (Al.sub.2O.sub.3), hafnium oxide, zirconium oxide,
indium oxide, tin oxide, and the like. Mixed structure oxides that
can be made using the process of the present invention can include,
for example, InZnO. Doped materials that can be made using the
process of the present invention can include, for example, ZnO:Al,
Mg.sub.xZn.sub.1-xO, and LiZnO.
[0052] A dielectric material is any material that is a poor
conductor of electricity. Such materials typically exhibit a bulk
resistivity greater than 10.sup.10 .OMEGA.-cm. Examples of
dielectrics are SiO.sub.2, MO, ZrO, SiNx, and Al.sub.2O.sub.3. A
semiconductor is a material in which electrical charges can move
but in which the concentration of electrical charges can be
substantially modulated by external factors such as electrical
fields, temperature, or injection of electrical charges from a
neighboring material. Examples of semiconductors include silicon,
germanium, and gallium arsenide. Particularly preferred
semiconductors are zinc oxide, indium zinc oxide, and gallium
indium zinc oxide. The semiconductors may be doped to render them
n-type or p-type, or to modulate the number of charge carriers
present.
[0053] Metals that can be made using the process of the present
invention include, but are not limited to: copper, tungsten,
aluminum, nickel, ruthenium, and rhodium. It will be apparent to
the skilled artisan that alloys of two, three, or more metals may
be deposited, compounds may be deposited with two, three, or more
constituents, and such things as graded films and nano-laminates
may be produced as well.
[0054] These variations are simply variants using particular
embodiments of the invention in alternating cycles. There are many
other variations within the scope of the invention, so the
invention is limited only by the claims that follow.
[0055] For various volatile zinc-containing precursors, precursor
combinations, and reactants useful in ALD thin film processes,
reference is made to the Handbook of Thin Film Process Technology,
Vol. 1, edited by Glocker and Shah, Institute of Physics (IOP)
Publishing, Philadelphia 1995, pages B1.5:1 to B1.5:16, hereby
incorporated by reference, and Handbook of Thin Film Materials,
edited by Nalwa, Vol. 1, pages 103 to 159, hereby incorporated by
reference, including Table V1.5.1 of the former reference.
[0056] Although oxide substrates provide groups for ALD deposition,
plastic substrates can be used by suitable surface treatment.
[0057] In a preferred embodiment, ALD can be performed at or near
atmospheric pressure and over a broad range of ambient and
substrate temperatures, preferably at a temperature of under
300.degree. C. Preferably, a relatively clean environment is used
to minimize the likelihood of contamination; however, full "clean
room" conditions or an inert gas-filled enclosure would not be
required for obtaining good performance when using preferred
embodiments of the process of the present invention.
[0058] Optionally, the present process can be accomplished using a
new ALD process which negates the need for a vacuum chamber. This
process, commonly referred to as S-ALD, is described in at least
one of commonly assigned U.S. Pat. Nos. 7,413,982; 7,456,429;
7,789,961; and US Patent Application Publication No. US
2009/0130858. All of the above-identified patents and patent
applications are incorporated by reference herein in their
entirety.
[0059] Two suitable approaches to combining patterning and
depositing the semiconductor are described in US Patent Application
Publication No. 2009/0081827 A1, published to Yang et al., on Mar.
26, 2009, the disclosure of which is hereby incorporated by
reference in its entirety; and U.S. Pat. No. 8,017,183 B2, issued
to Yang et al., on Sep. 13, 2011, the disclosure of which is hereby
incorporated by reference in its entirety. Given that the preferred
subsequent layers are deposited and conformally coated by atomic
layer deposition (ALD), preferred deposition inhibitor materials
are described in U.S. Pat. No. 7,998,878 B2, issued to Levy et al.,
on Aug. 16, 2011, the disclosure of which is hereby incorporated by
reference in its entirety.
[0060] Turning now to the figures, FIG. 1 is a diagrammatic Step
diagram for one embodiment of a process of the present invention
for making a patterned thin film inorganic layer using a
combination of selected area deposition (SAD) and ALD. As shown in
Step 1, a substrate is provided into the system. The substrate may
be any substrate as discussed that is suitable for use in the ALD
system.
[0061] In Step 10 a polymer deposition inhibitor material is
uniformly deposited to form an unpatterned layer or area. The
uniformity of the thickness of the unpatterned layer or area is not
critical to the invention. The deposition inhibitor material can be
any polymer based material that causes the material deposition to
be inhibited and should be understood from the previous
descriptions. In one embodiment, the polymer deposition inhibitor
material is chosen specifically for the material to be deposited.
In other embodiments, the deposition inhibitor material has a given
inhibition power. The inhibition power is defined as the layer
thickness at or below which the deposition inhibitor material is
effective. The uniform deposition of the polymer deposition
inhibitor material can only cover a portion of the substrate.
[0062] Next, a patterned mask layer is provided on the uniform
inhibitor layer as shown in step 20. Providing the mask can be
placing a shadow mask on the surface of the uniform inhibitor layer
or can be printing a patterned mask layer on the inhibitor layer.
In embodiments using a printed patterned mask, the printing process
can be any process known in the art such as inkjet, flexography,
gravure printing, microcontact printing, offset lithography, patch
coating, screen printing, or transfer from a donor sheet. The
patterned mask layer can be a polymer material, dye, pigment,
surfactant or any other material that can serve to mask the polymer
inhibitor layer from exposure to the highly reactive oxygen
process.
[0063] In step 30, the polymeric deposition inhibitor material is
patterned by removing the inhibitor in the areas not covered by the
patterned mask layer. The etching can be done using any highly
reactive oxygen processes including a UV-ozone process (UVO) or
O.sub.2 plasma. The highly reactive oxygen processes can be a batch
process using a chamber based tool or continuous process using web
process tools. The highly reactive oxygen processes can be at
sub-atmospheric (vacuum) pressure or atmospheric pressure. In some
embodiments, the patterning of the polymer deposition material
includes removing the patterned mask layer after the etching is
complete. In a preferred embodiment using a printed patterned mask,
the patterning of the deposition material can simultaneously etch
away the printed patterned mask layer, leaving only the patterned
deposition material on the surface. In another preferred embodiment
the patterning of the deposition material can simultaneously etch
away the patterned mask layer and a portion of the polymer
inhibitor deposition material, leaving only the patterned
deposition material on the surface which is thinner than the
original uniform coating applied in step 10.
[0064] In step 52, an inorganic thin film layer is deposited by
ALD. The patterned polymer inhibitor inhibits the deposition of the
inorganic thin film material so that the inorganic material only
deposits on the areas on the substrate where the inhibitor is not
present. As such, the inorganic thin film layer has the inverse
pattern to that of the patterned polymer inhibitor. Generally, this
deposition can be done using any ALD system, preferably a spatial
ALD system. The inorganic thin film layer can be any material that
can be deposited via ALD and whose growth is inhibited by the
polymer inhibitor layer.
[0065] After deposition of the inorganic layer, the patterned
inhibitor material can optionally be removed as shown in Step 60.
The polymer deposition inhibitor can be removed by a liquid process
using a solvent or a detergent. The liquid process can utilize a
mechanical action such as brushing or wiping or pressure jets. The
polymer deposition inhibitor can also be removed by a vapor
process. These processes include exposing the substrate to a vapor
reactant that causes removal of the inhibitor. The removal can
happen spontaneously upon reaction with the vapor, resulting in the
conversion of the inhibitor to a volatile species. Alternatively,
the vapor exposure can react with the inhibitor converting it to
another species or morphology that is then more easily removable
with another process, such as a liquid process. The vapor exposure
can include forms of energy to promote the process. These include
light exposure, and arcs or plasmas. Particularly desired light
exposures include UV exposure, especially in the presence of oxygen
to produce ozone. Plasmas include plasmas of various species
including oxygen, chlorine, and fluorine. Plasmas created with
these materials or with precursors that produce these materials are
included in the present invention.
[0066] FIG. 2 is a diagrammatic Step diagram for another embodiment
of a process of the present invention for making a patterned thin
film inorganic layer using a combination of selected area
deposition (SAD) and ALD. Steps 1 and 10 are the same as in FIG. 1
and should be understood from the previous description.
[0067] Next, a patterned mask layer is provided using a printing
process on the uniform inhibitor layer as shown in step 15. The
printing process can be any process known in the art such as
inkjet, flexography, gravure printing, microcontact printing,
offset lithography, patch coating, screen printing, or transfer
from a donor sheet. The patterned mask layer can be a polymer
material, dye, pigment, surfactant or any other material that can
serve to mask the polymer inhibitor layer from exposure to the
highly reactive oxygen process.
[0068] In step 30, the polymeric deposition inhibitor material is
patterned by removing the inhibitor in the areas not covered by the
printed patterned mask layer using a highly reactive oxygen
processes including a UV-ozone process (UVO) or O.sub.2 plasma.
These processes should be understood from previous descriptions.
Next, in step 22 the printed pattern mask is removed. The printed
pattern mask can be removed by a liquid process using a solvent or
a detergent. The liquid process can utilize a mechanical action
such as brushing or wiping or pressure jets. The printed pattern
mask can also be removed by a vapor process. These processes
include exposing the substrate to a vapor reactant that causes
removal of the printed mask material. The removal can happen
spontaneously upon reaction with the vapor, resulting in the
conversion of the inhibitor to a volatile species. Alternatively,
the vapor exposure can react with the printed mask material
converting it to another species or morphology that is then more
easily removable with another process, such as a liquid
process.
[0069] Next, in step 40 the substrate and the patterned polymeric
inhibitor layer are cleaned using a highly reactive oxygen
processes including a UV-ozone process (UVO) or O.sub.2 plasma.
This cleaning process can reduce the thickness of the polymeric
inhibitor layer, so that the patterned polymeric deposition
material on the surface after cleaning is thinner than the original
uniform coating applied in step 10. The reduction in thickness of
the polymeric inhibitor layer during the cleaning process is less
that 75%, preferably less than 50%, and more preferably less than
25%.
[0070] In step 52, an inorganic thin film layer is deposited by
ALD. The patterned polymer inhibitor inhibits the deposition of the
inorganic thin film material so that the inorganic material only
deposits on the areas on the substrate where the inhibitor is not
present
[0071] After deposition of the inorganic layer, the patterned
inhibitor material can optionally be removed as shown in Step 60.
The polymer deposition inhibitor can be removed by any reasonable
process known in the art, and processes described in reference to
FIG. 1 are preferred.
[0072] The process flows described in FIGS. 1 and 2 can be better
understood through the descriptive process build shown in FIGS. 5a
through 5g. In FIG. 5a, the substrate 200 is provided as in Step 1
of FIG. 2. FIG. 5b shows the uniform polymer deposition inhibiting
material layer 210 on the substrate 200 after it is deposited in
Step 10 of FIG. 2. FIG. 5c illustrates the printed patterned mask
layer 220 which is printed on the surface of the uniform polymer
deposition inhibitor material 210 in Step 15 of FIG. 2. Pattern
mask layer 220 contains regions 215 where the mask material layer
is not present.
[0073] FIG. 5d shows the patterned polymeric deposition inhibiting
material layer 230 obtained etching the uniform polymer deposition
layer 210 using a highly reactive oxygen process as in Step 30 of
FIG. 2, and after the removal the printed pattern mask layer as in
Step 22 of FIG. 2. The pattern mask layer can be removed as part of
the etch process, or removed in a separate process step. The mask
can be removed by appropriate solvent wash. After removing the
pattern mask layer 220, the surface of the substrate 235 and the
patterned polymeric deposition inhibiting material layer 230 is
cleaned as in Step 40 of FIG. 2, leaving the structure shown in
FIG. 5e. The patterned polymeric inhibitor layer 232 of FIG. 5e is
thinner than the layer 230 prior to the cleaning process. This
process also cleans the surface of the substrate that will be
deposited, removing any residue that can be present from the mask
removal process. This cleaning process preferably removes less than
500 .ANG. of material, more preferably less than 250 .ANG. of
material.
[0074] The thinner patterned deposition inhibiting material layer
232 contains regions 235 where the deposition inhibitor is not
present. Next, the patterned inorganic thin film material 240 is
deposited by treating the substrate surface to an ALD coating such
that the inorganic thin film material is only deposited in the
regions 235 where the deposition inhibiting material is not present
as shown in FIG. 5f (Step 52 of FIG. 2). After the inorganic film
is deposited, the patterned deposition inhibiting material layer
232 can be optionally removed as in Step 60 of FIG. 2, resulting in
the patterned inorganic thin film layer 240 as shown in FIG.
5g.
[0075] The descriptive process build shown in FIGS. 6a through 6f
illustrate an alternative embodiment of the present invention. In
FIG. 6a, the substrate 200 is provided as in Step 1 of FIG. 1. FIG.
6b shows the uniform polymer deposition inhibiting material layer
210 on the substrate 200 after it is deposited in Step 10 of FIG.
1. FIG. 6c illustrates the printed patterned mask layer 220 which
is printed on the surface of the uniform polymer deposition
inhibitor material 210 in Step 20 of FIG. 1. Pattern mask layer 220
contains regions 215 where the mask material layer is not
present.
[0076] FIG. 6d shows the patterned polymeric deposition inhibiting
material layer 230 obtained etching the uniform polymer deposition
inhibitor layer 210 using a highly reactive oxygen process as in
Step 30 of FIG. 1. As shown in FIG. 6d the highly reactive oxygen
process has removed the printed pattern mask layer 220 and removed
a portion of the uniform polymer inhibitor layer 210 resulting in
patterned polymeric inhibitor layer 232.
[0077] The patterned deposition inhibiting material layer 232
contains regions 235 where the deposition inhibitor is not present.
Next, the patterned inorganic thin film material 240 is deposited
by treating the substrate surface to an ALD coating such that the
inorganic thin film material is only deposited in the regions 235
where the deposition inhibiting material is not present as shown in
FIG. 6f (Step 52 of FIG. 1). After the inorganic film is deposited,
the patterned deposition inhibiting material layer 232 can be
optionally removed as in Step 60 of FIG. 1, resulting in the
patterned inorganic thin film layer 240 as shown in FIG. 6g.
[0078] FIG. 3 is a diagrammatic Step diagram for one embodiment of
a process of the present invention for making a patterned thin film
inorganic layer using a combination of selected area deposition
(SAD) and ALD. As shown in Step 12 a substrate having a patterned
thin layer of polymeric inhibitor material is provided. The
substrate may be any substrate as discussed that is suitable for
use in the ALD system. The patterned thin layer of polymeric
inhibitor material was patterned prior to Step 12 and could have
been patterned using any method known in the art, including
photolithography and printing methods. The deposition inhibitor
material can be any polymer based material that causes the material
deposition to be inhibited and should be understood from the
previous descriptions. In one embodiment, the polymer deposition
inhibitor material is chosen specifically for the material to be
deposited. In other embodiments, the deposition inhibitor material
has a given inhibition power. The inhibition power is defined as
the layer thickness at or below which the deposition inhibitor
material is effective.
[0079] Next, in Step 50 the substrate and the patterned polymeric
inhibitor layer are cleaned using a highly reactive oxygen
processes such as UV-ozone process (UVO) or O.sub.2 plasma. This
cleaning process can reduce the thickness of the polymeric
inhibitor layer, so that the patterned polymeric deposition
material on the surface after cleaning is thinner than the original
patterned layer provided in Step 12. The reduction in thickness of
the polymeric inhibitor layer during the cleaning process is less
that 75%, preferably less than 50%, and more preferably less than
25%.
[0080] In step 52, an inorganic thin film layer is deposited by
ALD. The patterned polymer inhibitor inhibits the deposition of the
inorganic thin film material so that the inorganic material only
deposits on the areas on the substrate where the inhibitor is not
present.
[0081] After deposition of the inorganic layer, the patterned
inhibitor material can optionally be removed as shown in Step 60.
The polymer deposition inhibitor can be removed any reasonable
process known in the art, and processes described in reference to
FIG. 1 are preferred.
[0082] The process flow described in FIG. 3 can be better
understood through the descriptive process build shown in FIGS. 7a
through 7d. In FIG. 7a, the substrate 400 with the patterned
polymeric deposition inhibitor layer 430 is provided as in Step 12
of FIG. 3. FIG. 7b shows the patterned polymeric deposition
inhibiting material layer 432 obtained after cleaning the substrate
400 and inhibitor layer 430 as in Step 50 of FIG. 3. The patterned
polymeric inhibitor layer 432 of FIG. 7b is thinner than the layer
430 prior to the cleaning process. This cleaning process uses a
highly reactive oxygen processes such as UV-ozone process (UVO) or
O.sub.2 plasma. This process also cleans the surface of the
substrate that will be deposited, removing any residue that may be
present from the mask removal process. This cleaning process
preferably removes less than 500 .ANG. of material is removed, more
preferably less than 250 .ANG. of material.
[0083] The patterned deposition inhibiting material layer 432
contains regions 435 where the deposition inhibitor is not present.
Next, the patterned inorganic thin film material 440 is deposited
by treating the substrate surface to an ALD coating such that the
inorganic thin film material is only deposited in the regions 435
where the deposition inhibiting material is not present as shown in
FIG. 7c (Step 52 of FIG. 3). After the inorganic film is deposited,
the patterned deposition inhibiting material layer 432 can be
optionally removed as in Step 60 of FIG. 3, resulting in the
patterned inorganic thin film layer 440 as shown in FIG. 7d.
[0084] In semiconductor processing, it is sometimes desirable to
have two layers of different materials that have the same pattern.
Depending on the composition of the two layers, it may not be easy
to uniformly deposit and then pattern the materials. In FIG. 4, a
diagrammatic Step diagram is shown for one embodiment of a process
of the present invention for making a patterned thin film inorganic
material stack using a combination of selected area deposition
(SAD) and ALD. As shown in Step 1, a substrate is supplied into the
system. In Step 10 a uniform deposition inhibitor material is
deposited. The deposition inhibitor material can be any material
that causes the material deposition to be inhibited and should be
understood from the previous descriptions. In one embodiment, the
deposition inhibitor material is chosen specifically for the
material to be deposited. In other embodiments, the deposition
inhibitor material has a given inhibition power. The inhibition
power is defined as the layer thickness at or below which the
deposition inhibitor material is effective. Next, a patterned mask
layer is deposited onto the uniform inhibitor layer using a
printing process as shown in step 15. The printing process can be
any process known in the art such as inkjet, flexography, gravure
printing, microcontact printing, offset lithography, patch coating,
screen printing, or transfer from a donor sheet. The patterned mask
layer can be a polymer material, dye, pigment, surfactant or any
other material that can serve to mask the polymer inhibitor layer
from exposure to the UVO treatment. In step 22, the deposition
inhibitor material is patterned using a highly reactive oxygen
processes such as UV-ozone process (UVO) or O.sub.2 plasma removing
the inhibitor material in the areas not covered by the patterned
mask layer and should be understood with respect to the earlier
descriptions
[0085] Continuing with FIG. 4, Step 55 deposits the desired first
thin film material by an Atomic Layer Deposition (ALD) process.
Generically this deposition can be using any ALD system, preferably
a spatial ALD system. The first thin film material is deposited
only in the areas of the substrate where there is no deposition
inhibitor material. After the first thin film material is deposited
in Step 55, a second thin film material layer is deposited by ALD
in Step 57. The second thin film material is deposited only in the
areas of the substrate where there is no deposition inhibitor
material, and as such is patterned into the same pattern as the
first thin film material layer. The layer thickness of the first
and second thin film inorganic materials can be the same or
different. After depositing the second thin film material, the
deposition inhibitor material can be optionally removed in Step 60
and should be understood with respect to the earlier description of
FIG. 1.
[0086] FIGS. 8a through 8g are a schematic diagram for one
embodiment of a method of producing an inorganic multi-layered thin
film structure using a combination of selected area deposition
(SAD) and ALD and the process described in FIG. 4. In FIG. 8a, the
substrate 300 is provided as in Step 1 of FIG. 4. FIG. 8b shows the
uniform polymer deposition inhibiting material layer 310 on the
substrate 300. FIG. 8c illustrates the patterned mask layer 320.
Pattern mask layer 320 contains regions 315 where the mask material
layer is not present.
[0087] FIG. 8d shows the patterned deposition inhibiting material
layer 330 obtained after etching the uniform polymer deposition
layer 310 using highly reactive oxygen processes such as UV-ozone
process (UVO) or O.sub.2 plasma. The patterned deposition
inhibiting material layer 330 contains regions 335 where the
deposition inhibitor is not present. Next, the first patterned
inorganic thin film material 340 is deposited by treating the
substrate surface to an ALD coating such that the inorganic thin
film material is only deposited in the regions 335 where the
deposition inhibiting material is not present as shown in FIG. 8e.
FIG. 8f shows the result of deposition of a second inorganic thin
film by an Atomic Layer Deposition (ALD) process on the substrate,
resulting in patterned second inorganic thin film material 345 in
the same areas 335 as the first inorganic thin film 340 and little
to no deposition of the second inorganic thin film in areas covered
by deposition inhibitor 330. The resulting inorganic multi-layered
thin film structure 350 now includes a stack of two inorganic thin
films 340 and 345. FIG. 8g shows the substrate after an optional
removal of the deposition inhibitor, leaving substantially only the
inorganic multi-layered thin film structures 350 on the original
substrate 300.
[0088] The first inorganic thin film material layer 340 and the
second inorganic thin film material layer 345 can have different
material compositions. The difference in material composition can
include differences in one or more of the atomic constituents that
compose the inorganic thin film. The difference in composition can
include only a change in the atomic ratio of the constituents that
compose the inorganic thin film.
[0089] The first inorganic thin film material layer 340 can include
a dielectric material and the second inorganic thin film material
layer can include a semiconductor material 345, wherein selectively
depositing the second inorganic thin film material layer includes
selectively depositing the second inorganic thin film material
layer on the first inorganic thin film material layer after the
first inorganic thin film material layer has been deposited on the
substrate. Alternatively, the first inorganic thin film material
layer 340 is a semiconductor material and the second inorganic thin
film material layer 345 is a dielectric material, and selectively
depositing the second inorganic thin film material layer includes
selectively depositing the second inorganic thin film material
layer on the first inorganic thin film material layer after the
first inorganic thin film material layer has been deposited on the
substrate.
[0090] FIGS. 9a through 9f are a schematic diagram for an
alternative embodiment of a method of producing an inorganic
multi-layered thin film structure using a combination of selected
area deposition (SAD) and ALD. In FIG. 9a, a substrate 500 with a
patterned thin polymer deposition inhibitor layer 530 is shown. The
patterned thin polymer deposition inhibitor layer 530 contains
regions 515 where the inhibitor material layer is not present. FIG.
9b shows the polymer deposition inhibiting material layer 532 after
cleaning the patterned thin polymer deposition inhibitor layer 530
and the substrate surface in 535 using a highly reactive oxygen
processes such as UV-ozone process (UVO) or O.sub.2 plasma. The
patterned deposition inhibiting material layer 532 contains regions
the same regions 335 where the deposition inhibitor is not present.
Next, the first patterned inorganic thin film material 540 is
deposited by treating the substrate surface to an ALD coating such
that the inorganic thin film material is only deposited in the
regions 535 where the deposition inhibiting material is not present
as shown in FIG. 9c.
[0091] FIG. 9d shows the polymer deposition inhibiting material
layer 534 after cleaning the patterned thin polymer deposition
inhibitor layer 532 and the surface of the first inorganic thin
film material layer 540 using a highly reactive oxygen processes
such as UV-ozone process (UVO) or O.sub.2 plasma. The patterned
thin polymer deposition inhibitor layer 534 is thinner than the
patterned thin polymer deposition inhibitor layer 532. Next, the
second patterned inorganic thin film material 545 is deposited by
treating the substrate surface to an ALD coating such that the
inorganic thin film material is only deposited in the regions 335
containing the first inorganic thin film layer and where the
deposition inhibiting material is not present as shown in FIG.
9e.
[0092] The resulting inorganic multi-layered thin film structure
550 now includes a stack of two inorganic thin films 540 and 545.
FIG. 9f shows the substrate after an optional removal of the
deposition inhibitor, leaving substantially only the inorganic
multi-layered thin film structures 550 on the original substrate
500.
[0093] The first inorganic thin film material layer 540 and the
second inorganic thin film material layer 545 can have the same or
different material compositions. In embodiments where the 540 and
545 are the same material, the material is preferably a dielectric
material. As used here, the same material includes materials with
the same chemical composition, but different levels of impurities.
Due to the sequential processing of the two inorganic thin film
material layers and the exposure of the interface to a highly
reactive oxygen processes, there will be a compositional signature
at the interface even in cases where layers 540 and 545 are the
same material. Often during the treatment of the interface the
surface of the substrate will acquire a difference in chemical
composition. This can manifest itself as a variation in the
concentration of atomic species formally included in the deposition
materials or as the presence of impurity atoms or molecules. This
difference in chemical composition is present at the interface
region between the patterned first inorganic thin film material 540
and patterned second inorganic thin film material 545. This
difference can be detected by depth profiling the patterned
inorganic thin film stack 550, where a small change in either the
relative amounts of the deposition materials or impurities will be
detected at the interface or contact region between the two layers.
One analytical technique that can be used for depth profiling films
is time-of-flight secondary ion mass spectroscopy (ToF SIMS).
Examples
Description of the Coating Apparatus
[0094] All of the following thin film examples employ a flow setup
as indicated in FIG. 28. The flow setup is supplied with nitrogen
gas flow 81 that has been purified to remove oxygen and water
contamination to below 1 ppm. The gas is diverted by a manifold to
several flow meters which control flows of purge gases and of gases
diverted through bubblers to select the reactive precursors. In
addition to the nitrogen supply, air flow 90 is also delivered to
the apparatus. The air is pretreated to remove moisture.
[0095] The following flows are delivered to the ALD coating
apparatus: metal (zinc) precursor flow 92 containing metal
precursors diluted in nitrogen gas; oxidizer-containing flow 93
containing non-metal precursors or oxidizers diluted in nitrogen
gas; and nitrogen purge flow 95 composed only of the inert gas. The
composition and flows of these streams are controlled as described
below.
[0096] Gas bubbler 83 contains liquid dimethylaluminum isopropoxide
(DMAI) and gas bubbler 82 contains diethyl zinc (DEZ). Flow meter
86 and flow meter 85 deliver flows of pure nitrogen to the
bubblers. The output of the bubbler now contains nitrogen gas
saturated with the respective precursor solution. The output flow
is mixed with a nitrogen gas dilution flow delivered from flow
meter 87 to yield the overall flow of metal precursor flow 92. In
the following examples, the flows for the dielectric material are
as follows: [0097] Flow meter 86: To Dimethylaluminum isopropoxide
Bubbler Flow [0098] Flow meter 87: To Metal Precursor Dilution
Flow
[0099] Gas bubbler 84 contains pure water at room temperature. Flow
meter 88 delivers a flow of pure nitrogen to gas bubbler 84, the
output of which represents a stream of saturated water vapor. An
airflow is controlled by flow meter 91. The water bubbler output
and air streams are mixed with dilution stream from flow meter 89
to produce the overall flow of oxidizer-containing flow 93 which
has a variable water vapor composition, nitrogen composition, and
total flow. In the following examples, the flows will be as
follows:
[0100] Flow meter 88: To Water Bubbler
[0101] Flow meter 89: To Oxidizer Dilution Flow
[0102] Flow meter 91: To Air Flow
[0103] Flow meter 94 controls the flow of pure nitrogen that is to
be delivered to the coating apparatus. Streams or Flows 92, 93, and
95 are then delivered to an atmospheric pressure coating head where
they are directed out of the channels or microchamber slots as
indicated in FIG. 29. A gap 99 exists between the elongated
channels and the substrate 97. Substrate 97 is maintained in close
proximity to the output face 105 by an equilibrium between the flow
of the gases supplied to the output face and a slight amount of
vacuum produced at the exhaust slot.
[0104] In order to perform a deposition, the delivery head 100 is
positioned over a portion of the substrate 97 and then moved in a
reciprocating fashion over the substrate 97, as represented by the
arrow 98. The length of the reciprocation cycle was 32 mm. The rate
of motion of the reciprocation cycle was varied as a deposition
parameter.
Materials Used:
[0105] (1) Glass substrates, cut to 2.5.times.2.5'' squares,
previously cleaned in Piranha solution, washed with distilled
water, reagent ethanol and dried.
[0106] (2) Dimethylaluminum isopropoxide (DMAI) (commercially
available from Strem Chemical Co.).
[0107] (3) Diethylzinc (DEZ) (commercially available from Strem
Chemical Co.).
[0108] (4) Polyvinylpyrrolidone (PVP) k-30 (commercially available
from Acros Organics).
General Conditions for the Preparation of Layers Using Atmospheric
Pressure ALD
[0109] This describes the preparation of a thin film coating of the
material layers on glass substrates as used in the examples. The
ALD coating device used to prepare these layers, namely
Al.sub.2O.sub.3, ZnO:N, and Al-doped ZnO (AZO), has been described
in detail in US Patent Application Publication No. US 2009/0130858,
the disclosure of which is incorporated by reference herein in its
entirety. The coating device has an output face (facing up) that
contains spatially separated elongated gas channels and operates on
a gas bearing principle. The coating device can be understood with
respect to FIGS. 28 and 29. Each gas channel is composed of an
output slot 95, 93, 92 which supplies gas to the output face 105,
and adjacent exhaust slots 110 which remove gas from the output
face 105. The order of the gas channels is P-O-P-M-P-O-P-M-P-O-P
where P represents a purge channel, O represents a channel
containing an oxygen based precursor, and M represents a channel
containing a metal based precursor. As a substrate moves relative
to the coating head it sees the above sequence of gases which
effects and ALD deposition.
[0110] A 2.5.times.2.5 inch square (62.5 mm square) glass substrate
attached to a heated backer is positioned on the output face of the
coating device and is maintained in close proximity to the output
face by an equilibrium between the flow of the gases supplied to
the output face and a slight amount of vacuum produced at the
exhaust slot. For all of the examples, the exhaust slot pressure
was approximately 40 inches of water below atmospheric pressure.
The purge gas P is composed of pure nitrogen. The oxygen reactive
precursor O is a mixture of nitrogen, water vapor, and optionally
ammonia vapor. The metal reactive precursor M is one or a mixture
of active metal alkyls vapor in nitrogen.
[0111] The metal alkyl precursors used in these examples were
dimethylaluminum isopropoxide (DMAI) and diethyl zinc (DEZ). The
flow rate of the active metal alkyl vapor was controlled by
bubbling nitrogen through the pure liquid precursor contained in an
airtight bubbler by means of individual mass flow control meters.
This saturated stream of metal alkyl was mixed with a dilution flow
before being supplied to the coating device. The flow of water
vapor was controlled by adjusting the bubbling rate of nitrogen
passed through pure water in a bubbler. This saturated stream of
water vapor was mixed with a dilution flow before being supplied to
the coating device. The flow of ammonia vapor was controlled by
passing pure ammonia vapor from a compressed fluid tank through and
mass flow controller and mixing with the water vapor stream. All
bubblers were at room temperature. The temperature of the coating
was established by controlling heating both the coating device and
the backer to a desired temperature. Experimentally, the flow rates
of the individual gasses were adjusted to the settings shown in
Table 1 for each of the material layers coated in the examples
contained herein. The flows shown are the total flows supplied to
the coating device, and thus are partitioned equally among the
individual gas channels.
[0112] The coating process was then initiated by oscillating the
coating head across the substrate for the number of cycles
necessary to obtain a uniform deposited film of the desired
thickness for the given example. Due to the fact that the coating
head as described above contains two full ALD cycles (two oxygen
and two metal exposures per single direction pass over the head), a
round trip oscillation represents 4 ALD cycles.
TABLE-US-00001 TABLE 1 N.sub.2 dilution N.sub.2 DMAI DEZ Water with
dilution N.sub.2 bubbler bubbler NH3 bubbler Metal with Inert
Residence Substrate flow flow flow flow Alkyl water Purge Time
Temperature, Layer (sccm) (sccm) (sccm) (sccm) (sccm) (sccm) (sccm)
(ms) .degree. C. Al.sub.2O.sub.3 65 0 0 65 1500 2250 3000 100 200
ZnO 0 60 0 45 1500 2250 3000 50 200 AZO 10 30 0 22.5 1500 2250 3000
50 200
Inhibitor Effectiveness after UV-Ozone Exposure
[0113] In order determine to whether inhibitors would still inhibit
after being exposed to an UV-ozone plasma, a number of experiments
were run. A detailed description of the samples and their
respective testing conditions follows.
Comparative Example C1
Polyvinyl Pyrrolidone k80
[0114] Comparative Example C1 was prepared by first O.sub.2 plasma
cleaning a silicon substrate. Next, a 0.5 wt % solution of PVP k80
in diacetone alcohol was spun coat on the silicon at 3000 rpm
followed by a one minute hot plate bake at 180 C, resulting in a
160 .ANG. film of PVP. A shadow mask was then placed in contact
with the polymer surface and the sample was exposed to 15 minutes
of UV-ozone treatment using a JELIGHT model 342 UVO cleaner with
the substrate placed close (within an inch) to the UV source. After
the UVO, 1/4 of the PVP was removed from the sample by wiping in
order to provide a reference area for the thin film ALD growth.
Next, the sample was exposed to 600 ALD cycles at 200.degree. C. at
the conditions listed for ZnO in Table 1, using the SALD system
described above, to deposit approximately 1100 .ANG. of ZnO in the
reference area. Then the sample was subjected to a 2 minute O.sub.2
plasma to remove the inhibitor to verify the inhibition of the ZnO
growth. The sample was visually inspected, and the results can be
found in Table 2.
Comparative Example C2
Polyvinyl Pyrrolidone k80
[0115] Comparative Example C2 was prepared like Comparative Example
C2 except PVP k30 was used in place of the PVP k80. The sample was
completed and inspected as in comparative example C1; results can
be found in Table 2.
Inventive Example I1
PMMA 950
[0116] Inventive example I1, was prepared as comparative example C1
with the following exception. Instead of coating PVP k80 as the
inhibitor layer, a 0.5 wt % solution of PMMA 950 in anisole was
used. The sample was completed and inspected as in comparative
example C1 results can be found in Table 2.
TABLE-US-00002 TABLE 2 Nominal Able to Inhibitor Inhibitor Layer
Patterned by Direct 1100 .ANG. Sample material Thickness (.ANG.) 15
min UVO of ZnO C1 PVP k80 160 Yes No C2 PVP k30 160 Yes No I1 PMMA
950 160 Yes Yes
[0117] As can be seen in Table 2, all samples could be patterned
using UVO to remove the polymer inhibitor. However, the inventive
samples of PMMA retained its ability to direct the ALD growth while
comparative examples C1 and C2 lost their ability to inhibit due to
exposure to UVO.
Printed Masks for UV-Ozone Exposure Patterning
[0118] In order determine to printed masks would be useful to
pattern polymeric inhibitors, a number of experiments were run. A
detailed description of the samples and their respective testing
conditions follows.
Inventive Example I2
PMMA 950 Using an Inkjet Dye-Base Ink Patterned Mask
[0119] Inventive example I2, was prepared as inventive example I1
with the following exceptions. After baking the PMMA at 180 C, 1/2
the sample was covered with a black dye-based inkjet in (Prosper
S-series 6080020-01). The sample was then exposed to 15 minutes of
UVO as in inventive example I1. After the UVO treatment, the sample
was rinsed with DI water to remove the ink, and subjected to a 3
minute UVO treatment to refresh the surface. The thickness of the
PMMA was measured via elipsometry after each step, and the results
can be found in Table 3.
Inventive Example I3
PMMA 950 Using an Inkjet Pigment-Base Ink Patterned Mask
[0120] Inventive example I3, was prepared as inventive example I2
with the following exception. Instead of using a dye-based ink to
as a mask, a pigmented black ink was used (Prosper K 11007). The
sample was then completed and measured like I2, and the results can
be found in Table 3.
Inventive Example I4
PMMA 950 Using Surfactant Patterned Mask
[0121] Inventive example I4, was prepared as inventive example I2
with the following exception. Instead of using a dye-based ink to
as a mask, highly concentrated solution of surfactant was used
(FAC-0005). The sample was then completed and measured like I2,
except that I4 did not receive the 3 min treatment after the
removal of the patterned mask. The results for I4 can be found in
Table 3.
TABLE-US-00003 TABLE 3 PMMA Native oxide in PMMA after after 3 min
Initial PMMA PMMA area ink removal in UVO Samples thickness (.ANG.)
after UVO (.ANG.) DI water (.ANG.) descum I2 106.19 14.68 118.61
98.46 I3 110.59 28.57 98.46 118.61 I4 120* 13.83 116.48 n/a
[0122] As can be seen in Table 3, a variety of masking inks can be
used to pattern the PMMA in combination with a UVO etching
process.
Inhibitor Effectiveness after Patterning with UV-Ozone Exposure
[0123] In order determine if polymeric inhibitors patterned using
UV-ozone were still effective at inhibiting ALD growth, a number of
experiments were run. A detailed description of the samples and
their respective testing conditions follows.
Inventive Example I5
PMMA 950 Using Surfactant Patterned Mask
[0124] Inventive example I5, was prepared as inventive example I4
with the following exception. The FAC solution was 2 wt % in DI
water. After removing the pattern mask, 1100 .ANG. of ZnO was
deposited using the SALD system described above, at 200.degree. C.
using 600 ALD cycles at the conditions listed for ZnO in Table 1.
Subsequent to ZnO growth, the PMMA was removed using an O.sub.2
plasma. The thicknesses of the inhibitor layer and inorganic thin
film layer were measured using elipsometry. The results for 15 can
be found in Table 4.
TABLE-US-00004 TABLE 4 ZnO on Initial PMMA after UVO PMMA ink
removal in cleaned area PMMA after ink Sample thickness (.ANG.) DI
water (.ANG.) (.ANG.) ZnO growth (.ANG.) I5 153.01 166.55 1111.73
148.57
[0125] As can be seen in Table 4, the PMMA inhibitor patterned
using a masking ink in combination with a UVO etching process can
effectively inhibit ZnO growth.
Inhibitor Effectiveness after O.sub.2 Plasma
[0126] In order to probe whether inhibitors would still inhibit
after being exposed to an O.sub.2 plasma, a number of experiments
were run. A detailed description of the samples and their
respective testing conditions follows.
Comparative Example C3
PDMS
[0127] Comparative example C3 was prepared by first O.sub.2 plasma
cleaning a silicon substrate. Next, a 2 wt % solution of Sylgard
184 in toluene was spun coat on the silicon at 3000 rpm and half of
the sample was wiped clean using toluene. It was very difficult to
remove the PDMS from the sample using wiping, resulting in
incomplete removal of the PDMS from the "clean" side of the sample.
This was followed by a one minute hot plate bake at 180 C,
resulting in a 455 .ANG. film of PDMS on half of the sample. Next
1100 .ANG. of ZnO was deposited using the SALD system described
above, at 200.degree. C. using 600 ALD cycles at the conditions
listed for ZnO in Table 1. The thicknesses of the inhibitor layer
and inorganic thin film layer were measured using elipsometry. The
results for C3 can be found in Table 5.
Comparative Example C4
PDMS after O.sub.2 Plasma
[0128] Comparative Example C4 was prepared like Comparative Example
C3 except that the sample was subjected to a 10 second 100 W
O.sub.2 plasma at 300 mTorr. The sample was completed and inspected
as in comparative example C3; results can be found in Table 5.
Inventive Example I6
PMMA 950 after O.sub.2 Plasma
[0129] Inventive example I7, was prepared as comparative example C4
with the following exception. Instead of coating PDMS as the
inhibitor layer, a 4 wt % solution of PMMA 950 in anisole was used.
The sample was completed and inspected as in comparative example C4
results can be found in Table 5.
Comparative Example C6
PMMA k75
[0130] Comparative example C6, was prepared as comparative example
C3 with the following exception. Instead of coating PDMS as the
inhibitor layer, a 2 wt % solution of PMMA k75 in toluene was used.
The sample was completed and inspected as in comparative example C1
results can be found in Table 5.
Inventive Example I7
PMMA k75 after O.sub.2 Plasma
[0131] Inventive example I7, was prepared as comparative example C4
with the following exception. Instead of coating PDMS as the
inhibitor layer, a 0.5 wt % solution of PMMA k75 in toluene was
used. Additionally, a 5 second O.sub.2 plasma treatment was used,
in place of the 10 second O.sub.2 plasma treatment of C4. The
sample was completed and inspected as in comparative example C4
results can be found in Table 5.
TABLE-US-00005 TABLE 5 Measured Measured ZnO Measured Inhibitor
thickness inhibitor Able to In- O.sub.2 Layer on clean thickness
Direct Sam- hibitor plasma Thickness substrate post ALD 1100 .ANG.
ple material treatment (.ANG.) (.ANG.) (.ANG.) of ZnO C3 PDMS No
455.47 159.2 411.94 Yes C4 PDMS Yes 360.09 1118 1416.8 No I6 PMMA
Yes 1160.35 1100.6 1078.36 Yes 950 C6 PMMA No 600.09 956.6 601.22
Yes k75 I7 PMMA Yes 286.1 1116.73 239.26 Yes k75
[0132] As can be seen in Table 5, all samples materials could
inhibit ALD growth prior to exposure to O.sub.2 plasma. However,
the inventive samples of PMMA and high and low molecular weights
retain their ability to direct the ALD growth while comparative
examples C4 lost their ability to inhibit due to exposure to
O.sub.2. The data in Table 5 also point to the need to clean the
substrate after patterning and prior to ALD to remove inhibitor
residues, as seen in comparative examples C3 and C6 residual
inhibitor leads to unwanted inhibition of the ALD coating.
Inhibitor Effectiveness after Patterning with O.sub.2 Plasma
Inventive Example I8
PMMA 950 Patterned Using O.sub.2 Plasma and Printed Polymer
Patterned Mask
[0133] Inventive example I8, was prepared in a manner similar to
that of inventive example I4. First a silicon substrate was
prepared by first O.sub.2 plasma cleaning. Next, a 2.4 wt %
solution of PMMA 950 was spun coat on the silicon at 3000 rpm
followed by a one minute hot plate bake at 180 C, nominally
resulting in a 1000 .ANG. film of PMMA. Next, a 10 wt % solution of
PVP K30 in water with 0.5 wt % surfactant was printed on half of
the substrate using a disposable pipette as a crude printing tool.
The sample was then exposed to a 30 second 100 W O.sub.2 plasma at
300 mTorr, which completely etched off the exposed PMMA. The PVP
printed mask was then removed by rinsing the sample in DI water.
Immediately following the rinse, nominally 1100 .ANG. of ZnO was
deposited using the SALD system described above, at 200.degree. C.
using 600 ALD cycles at the conditions listed for ZnO in Table 1.
The sample was measured using elipsometry after coating, after
O.sub.2 plasma and after SALD deposition and the results can be
found in Table 6.
Inventive Example I9
Refreshed PMMA 950 Patterned Using O.sub.2 Plasma and Printed
Polymer Patterned Mask
[0134] Inventive example I8, was prepared as inventive example I8
with the following exception. After removing the PVP pattern mask
the PMMA surface was refreshed and the exposed Si cleaned using a
short 5 minute 100 W O.sub.2 plasma at 300 mTorr. The sample was
then completed and measured like I8, and the results can be found
in Table 6.
TABLE-US-00006 TABLE 6 PMMA thickness PMMA PMMA SALD after 30
thickness PMMA refractive refractive second after thickness index
at index at Initial O.sub.2 additional after 700 nm SALD 700 nm
PMMA plasma + 5 second SALD after total after thickness Di water
plasma growth SALD SALD thickness SALD Sample (.ANG.) rinse (.ANG.)
(.ANG.) (.ANG.) growth layer (.ANG.) growth I8 1058.63 1037.23
1017.57 1.48 ZnO 1111.1 1.981 I9 1053.82 1042.58 715.48 647.01
1.466 ZnO 1117.78 1.98
[0135] As can be seen in Table 6, the PMMA inhibitor can be
successfully patterned using an O.sub.2 plasma and a printed
polymer mask. Also, inventive sample I9 shows that a freshly
O.sub.2 plasma'd PMMA surface is effective at inhibiting over 1000
.ANG. of ZnO growth.
Inhibitor Effectiveness after Patterning with O.sub.2 Plasma with
Simultaneous Mask Removal
Inventive Example I10
PMMA 950 Patterned by Etching Back a Printed Polymer Patterned
Mask
[0136] Inventive example I10, was prepared as inventive example I8
with the following exceptions. Instead of depositing the PVP using
a pipette, a thin layer of PVP was deposited over the PMMA by spin
coating the same PVP solution as used in I6 at 3000 rpm. After
coating, the PVP was removed from half of the sample using a DI
water rinse. The sample was then etched in an O.sub.2 plasma at 100
W and 300 mTorr for 115 seconds, which completely removed the
exposed PMMA, the PVP mask and a thin layer of the PMMA that was
under the PVP. After the plasma etch, ZnO was deposited as in
inventive example I8. The sample was measured using elipsometry,
and the results can be found in Table 7.
TABLE-US-00007 TABLE 7 PMMA SALD PMMA PMMA refractive refractive
thickness thickness index at index at Initial PMMA + after after
700 nm SALD 700 nm PMMA PVP etch SALD after total after thickness
thickness back growth SALD SALD thickness SALD Sample (.ANG.)
(.ANG.) (.ANG.) (.ANG.) growth layer (.ANG.) growth I10 1044.27
4175.63 724.61 680.6 1.481 ZnO 1113.54 1.978
[0137] As can be seen in Table 7, the PMMA inhibitor can be
successfully patterned using an O.sub.2 plasma and a printed
polymer mask such that the polymer mask is removed during the
etching process. Additionally, like inventive sample I9, inventive
sample I10 shows that a freshly O.sub.2 plasma'd PMMA surface is
effective at inhibiting over 1000 .ANG. of ZnO growth.
Patterned Inorganic Multilayer Films Formed by Patterning Inhibitor
with O.sub.2 Plasma
Inventive Example I11
Inorganic Multilayer Formed Using O.sub.2 Plasma Patterned PMMA
950
[0138] Inventive example I11, was prepared as inventive example I8
with the following exception. Instead of depositing 1100 .ANG. of
ZnO, a material stack was deposited by first depositing nominally
250 .ANG. of Al.sub.2O.sub.3 was deposited using the SALD system
described above, at 200.degree. C. using 580 ALD cycles at the
conditions listed for Al.sub.2O.sub.3 in Table 1. Next, nominally
200 .ANG. of ZnO was deposited using the SALD system described
above, at 200.degree. C. using 120 ALD cycles at the conditions
listed for Al.sub.2O.sub.3 in Table 1. The sample was measured
using elipsometry, and the results can be found in Table 8.
Inventive Example I12
Inorganic Multilayer Formed Using O.sub.2 Plasma Patterned PMMA
950
[0139] Inventive example I12, was prepared as inventive example I10
with the following exception. Prior to depositing ZnO PMMA surface
was refreshed and the exposed Al.sub.2O.sub.3 cleaned using a short
5 minute 100 W O.sub.2 plasma at 300 mTorr. The sample was then
completed and measured like I11, and the results can be found in
Table 8.
TABLE-US-00008 TABLE 8 PMMA PMMA SALD after 30 growth 1 second PMMA
and PMMA Initial O.sub.2 additional additional after SALD PMMA
plasma + 5 second 5 second SALD final total thickness Di water
plasma plasma SALD layer 1 SALD SALD thickness Samples (.ANG.)
rinse (.ANG.) (.ANG.) (.ANG.) layer 1 thickness growth layer 2
(.ANG.) I11 1066.03 1049.63 757.08 Al2O3 690.71 ZnO 458.45 I12
1066.24 1048.04 720.64 358.17 Al2O3 267.38 278.09 ZnO 468.08
[0140] As can be seen in Table 8, PMMA inhibitor patterned using an
O.sub.2 plasma can be used to form patterned inorganic multilayer
stacks. The surface of the first inorganic layer can be cleaned
prior to depositing the second inorganic layer without impacting
the ability of the PMMA to inhibit the SALD growth.
[0141] The invention has been described in detail with particular
reference to certain example embodiments thereof, but it will be
understood that variations and modifications can be effected within
the scope of the invention.
PARTS LIST
[0142] 1 providing a substrate [0143] 10 uniformly depositing a
thin layer of polymeric inhibitor material [0144] 12 providing a
substrate having a patterned thin layer of polymeric inhibitor
material [0145] 15 depositing a patterned mask layer using a
printing process [0146] 20 providing a patterned mask [0147] 22
removing the patterned mask [0148] 30 patterning the PMMA with a
highly reactive oxygen process [0149] 40 cleaning the substrate and
patterned polymeric inhibitor layer [0150] 50 cleaning the
substrate and the patterned thin layer of polymeric inhibitor
material using a highly reactive oxygen process [0151] 52 ALD
[0152] 55 Deposit a first inorganic thin film by ALD [0153] 57
Deposit a second inorganic thin film by ALD [0154] 60 Optionally
removing the polymeric deposition inhibitor material [0155] 65
Optionally removing the polymeric deposition inhibitor material
[0156] 81 nitrogen gas flow [0157] 82, 83, 84 gas bubbler [0158]
85, 86 flow meter [0159] 87, 88 flow meter [0160] 89, 91, 94 flow
meter [0161] 90 air flow [0162] 92 metal precursor flow [0163] 93
oxidizer-containing flow [0164] 94 nitrogen purge flow [0165] 96
substrate support [0166] 97 example substrate [0167] 98 arrow
[0168] 99 gap [0169] 100 delivery head [0170] 105 output face
[0171] 110 exhaust channels [0172] 200 substrate [0173] 210 uniform
polymer deposition inhibiting material layer [0174] 215 region
where the mask material layer is not present [0175] 220 patterned
mask layer [0176] 230 patterned polymer deposition inhibiting
material layer [0177] 232 partially removed patterned polymer
deposition inhibiting material layer [0178] 235 region where
polymer deposition inhibiting material layer is not present [0179]
240 patterned inorganic thin film material [0180] 300 substrate
[0181] 310 uniform polymer deposition inhibiting material layer
[0182] 315 region where the mask material layer is not present
[0183] 320 patterned mask layer [0184] 330 patterned polymer
deposition inhibiting material layer [0185] 335 region where the
polymer deposition inhibiting material layer is not present [0186]
340 patterned first inorganic thin film material [0187] 345
patterned second inorganic thin film material [0188] 350 inorganic
multi-layered thin film structure [0189] 400 substrate [0190] 430
patterned polymer deposition inhibiting material layer [0191] 432
partially removed patterned polymer deposition inhibiting material
layer [0192] 435 region where the polymer deposition inhibiting
material layer is not present [0193] 440 patterned inorganic thin
film material [0194] 500 substrate [0195] 530 patterned polymer
deposition inhibiting material layer [0196] 532 partially removed
patterned polymer deposition inhibiting material layer [0197] 534
partially removed patterned polymer deposition inhibiting material
layer [0198] 535 region where the polymer deposition inhibiting
material layer is not present [0199] 540 patterned first inorganic
thin film material [0200] 545 patterned second inorganic thin film
material [0201] 550 inorganic multi-layered thin film structure
* * * * *