U.S. patent application number 13/762749 was filed with the patent office on 2014-08-14 for block copolymer composition and methods relating thereto.
This patent application is currently assigned to ROHM AND HAAS ELECTRONIC MATERIALS LLC. The applicant listed for this patent is ROHM AND HAAS ELECTRONIC MATERIALS LLC. Invention is credited to Shih-Wei Chang, Valeriy Ginzburg, Xinyu Gu, Phillip Hustad, Daniel Murray, Peter Trefonas, Erin Vogel.
Application Number | 20140227448 13/762749 |
Document ID | / |
Family ID | 51272830 |
Filed Date | 2014-08-14 |
United States Patent
Application |
20140227448 |
Kind Code |
A1 |
Trefonas; Peter ; et
al. |
August 14, 2014 |
Block copolymer composition and methods relating thereto
Abstract
A copolymer composition is provided including a block copolymer
having a poly(acrylate) block and a poly(silyl acrylate) block;
wherein the block copolymer exhibits a number average molecular
weight, M.sub.N, of 1 to 1,000 kg/mol; and, wherein the block
copolymer exhibits a polydispersity, PD, of 1 to 2. Also provided
are substrates treated with the copolymer composition.
Inventors: |
Trefonas; Peter; (Medway,
MA) ; Hustad; Phillip; (Manvel, TX) ; Gu;
Xinyu; (Lake Jackson, TX) ; Vogel; Erin;
(Midland, MI) ; Ginzburg; Valeriy; (Midland,
MI) ; Chang; Shih-Wei; (Natick, MA) ; Murray;
Daniel; (Midland, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ROHM AND HAAS ELECTRONIC MATERIALS LLC |
Marlborough |
MA |
US |
|
|
Assignee: |
ROHM AND HAAS ELECTRONIC MATERIALS
LLC
Marlborough
MA
|
Family ID: |
51272830 |
Appl. No.: |
13/762749 |
Filed: |
February 8, 2013 |
Current U.S.
Class: |
427/385.5 ;
524/291 |
Current CPC
Class: |
C09D 153/00 20130101;
C08F 297/026 20130101; G03F 7/0002 20130101 |
Class at
Publication: |
427/385.5 ;
524/291 |
International
Class: |
C09D 153/00 20060101
C09D153/00 |
Claims
1. A copolymer composition, comprising: a block copolymer having a
poly(acrylate) block and a poly(silyl acrylate) block; and, an
antioxidant; wherein the block copolymer exhibits a number average
molecular weight, M.sub.N, of 1 to 1,000 kg/mol; wherein the
copolymer composition contains .gtoreq.2 wt % antioxidant (based on
the weight of the block copolymer) and, wherein the block copolymer
exhibits a polydispersity, PD, of 1 to 2.
2. The copolymer composition of claim 1, wherein the copolymer
composition contains 5 to 30 wt % antioxidant (based on the weight
of the block copolymer).
3. The copolymer composition of claim 1, wherein the antioxidant is
selected from the group consisting of: an antioxidant containing at
least one 2,6-di-tert-butylphenol moiety; an antioxidant containing
at least one moiety according to the formula ##STR00010## an
antioxidant containing at least one moiety according to the formula
##STR00011## an antioxidants containing at least one moiety
according to the formula ##STR00012## and, mixtures thereof.
4. The copolymer composition of claim 1, wherein the antioxidant is
selected from the group consisting of ##STR00013## ##STR00014##
and, mixtures thereof.
5. The copolymer composition of claim 1, wherein the poly(acrylate)
block includes residues from at least one of an acrylate monomer, a
deuterated acrylate monomer, an acrylate block modifying monomer
and a deuterated acrylate block modifying monomer; wherein the
poly(acrylate) block includes >75 wt % of acrylate monomer
derived units; wherein the acrylate monomer is selected from the
group consisting of C.sub.6-14 aryl (C.sub.1-5 alkyl)acrylate;
C.sub.1-5 alkyl (C.sub.1-5 alkyl)acrylate; wherein the deuterated
acrylate monomer is selected from the group consisting of
deuterated C.sub.6-14 aryl (C.sub.1-5 alkyl)acrylate; deuterated
C.sub.1-5 alkyl (C.sub.1-5 alkyl)acrylate; wherein the acrylate
block modifying monomer is selected from the group consisting of a
C.sub.1-5 alkene and a C.sub.3-7 cycloalkene; wherein the
deuterated acrylate block modifying monomer is selected from a
deuterated C.sub.1-5 alkene and deuterated a C.sub.3-7 cycloalkene;
and, wherein the poly(silyl acrylate) block includes residues from
at least one of a silyl acrylate monomer, a deuterated silyl
acrylate monomer, a silyl acrylate block modifying monomer and a
deuterated silyl acrylate block modifying monomer; wherein the
poly(silyl acrylate) block includes >75 wt % silyl acrylate
monomer derived units; wherein the silyl acrylate monomer is
according to the following formula
(R.sup.1(R.sup.2)(R.sup.3)Si).sub.rR.sup.4.sub.xOOCC(R.sup.5).dbd.CR.sup.-
6.sub.2 wherein each R.sup.1, R.sup.2 and R.sup.3 is independently
selected from the group consisting of a C.sub.1-6 alkyl group, a
silylated C.sub.1-6 alkyl group, an oxy C.sub.1-6 alkyl group, an
oxy silylated C.sub.1-6 alkyl group, a C.sub.6-10 aryl group, an
oxy C.sub.6-10 aryl group, a silylated C.sub.6-10 aryl group, an
oxy silylated C.sub.6-10 aryl group, a C.sub.1-10 arylalkyl group,
an oxy C.sub.1-10 arylalkyl group, a silylated C.sub.1-10 arylalkyl
group, an oxy silylated C.sub.1-10 arylalkyl group, a C.sub.6-10
alkylaryl group, an oxy C.sub.6-10 alkylaryl group, a silylated
C.sub.6-10 alkylaryl group, an oxy silylated C.sub.6-10 alkylaryl
group; wherein r is selected from the group consisting of 0, 1, 2
and 3; wherein R.sup.4 is selected from the group consisting of a
C.sub.1-3 alkyl; wherein x is selected from the group consisting of
0 and 1; wherein R.sup.5 is selected from the group consisting of a
hydrogen and a methyl group; wherein each R.sup.6 is a hydrogen;
wherein the silyl acrylate monomer includes at least one Si atom;
wherein the deuterated silyl acrylate monomer is according to the
following formula
(R.sup.7(R.sup.8)(R.sup.9)Si).sub.tR.sup.10.sub.yOOCC(R.sup.11).dbd.CR.su-
p.12.sub.2 wherein each R.sup.7, R.sup.8 and R.sup.9 is
independently selected from a C.sub.1-6 alkyl group, a silylated
C.sub.1-6 alkyl group, an oxy C.sub.1-6 alkyl group, an oxy
silylated C.sub.1-6 alkyl group, a C.sub.6-10 aryl group, an oxy
C.sub.6-10 aryl group, a silylated C.sub.6-10 aryl group, an oxy
silylated C.sub.6-10 aryl group, a C.sub.1-10 arylalkyl group, an
oxy C.sub.1-10 arylalkyl group, a silylated C.sub.1-10 arylalkyl
group, an oxy silylated C.sub.1-10 arylalkyl group, a C.sub.6-10
alkylaryl group, an oxy C.sub.6-10 alkylaryl group, a silylated
C.sub.6-10 alkylaryl group, an oxy silylated C.sub.6-10 alkylaryl
group, a deuterated C.sub.1-6 alkyl group, a deuterated silylated
C.sub.1-6 alkyl group, a deuterated oxy C.sub.1-6 alkyl group, a
deuterated oxy silylated C.sub.1-6 alkyl group, a deuterated
C.sub.6-10 aryl group, a deuterated oxy C.sub.6-10 aryl group, a
deuterated silylated C.sub.6-10 aryl group, a deuterated oxy
silylated C.sub.6-10 aryl group, a deuterated C.sub.1-10 arylalkyl
group, a deuterated oxy C.sub.1-10 arylalkyl group, a deuterated
silylated C.sub.1-10 arylalkyl group, a deuterated oxy silylated
C.sub.1-10 arylalkyl group, a deuterated C.sub.6-10 alkylaryl
group, a deuterated oxy C.sub.6-10 alkylaryl group, a deuterated
silylated C.sub.6-10 alkylaryl group and a deuterated oxy silylated
C.sub.6-10 alkylaryl group; wherein t is selected from the group
consisting of 0, 1, 2 and 3; wherein R.sup.10 is selected from the
group consisting of a C.sub.1-3 alkyl group, and a deuterated
C.sub.1-3 alkyl; wherein y is 0 or 1; wherein R.sup.11 is selected
from the group consisting of a hydrogen, a deuterium, a methyl
group and a deuterated methyl group; wherein each R.sup.12 is
selected from a hydrogen and a deuterium; wherein the deuterated
silyl acrylate monomer contains at least one Si atom; and, wherein
the deuterated silyl acrylate monomer contains at least one
deuterium; wherein the silyl acrylate block modifying monomer is
selected from the group consisting of an alkene and a cycloalkene;
and, wherein the deuterated silyl acrylate block modifying monomer
is selected from the group consisting of a deuterated alkene and a
deuterated cycloalkene.
6. The copolymer composition of claim 5, wherein the copolymer
composition contains 5 to 30 wt % antioxidant (based on the weight
of the block copolymer).
7. The copolymer composition of claim 5, wherein the acrylate
monomer is selected from the group consisting of butyl
(meth)acrylate, propyl (meth)acrylate), ethyl (meth)acrylate,
methyl (meth)acrylate; wherein the deuterated acrylate monomer is
selected from the group consisting of deuterated butyl
(meth)acrylate, deuterated propyl (meth)acrylate), deuterated ethyl
(meth)acrylate, deuterated methyl (meth)acrylate; wherein the
acrylate block modifying monomer is ethylene; and, wherein the
deuterated acrylate block modifying monomer is deuterated ethylene;
and, wherein the silyl acrylate monomer is selected from the group
consisting of (trimethylsilyl)methyl (meth)acrylate,
(triethylsilyl)methyl (meth)acrylate, (tripropylsilyl)methyl
(meth)acrylate, (triisopropylsilyl)methyl (meth)acrylate,
(tributylsilyl)methyl (meth)acrylate, (tri-sec-butylsilyl)methyl
(meth)acrylate, (triisobutylsilyl)methyl (meth)acrylate,
(sec-butylmethylsilyl)methyl (meth)acrylate,
(sec-butyldimethylsilyl)methyl (meth)acrylate,
(dimethylpropylsilyl)methyl (meth)acrylate,
(monomethyldipropylsilyl)methyl (meth)acrylate,
(methylethylpropylsilyl)methyl (meth)acrylate,
bis(trimethylsilyl)methyl (meth)acrylate,
tris(trimethylsilyl)methyl (meth)acrylate,
(pentamethyldisilyl)methyl (meth)acrylate,
tris(trimethylsiloxy)methyl (meth)acrylate,
tris(trimethylsiloxy)propyl (meth)acrylate),
(pentamethyldisiloxy)methyl (meth)acrylate,
(pentamethyldisiloxy)propyl (meth)acrylate, (trimethoxysilyl)propyl
(meth)acrylate and (triethoxysilyl)propyl (meth)acrylate; wherein
the deuterated silyl acrylate monomer is selected from the group
consisting of deuterated (trimethylsilyl)methyl (meth)acrylate,
deuterated (triethylsilyl)methyl (meth)acrylate, deuterated
(tripropylsilyl)methyl (meth)acrylate, deuterated
(triisopropylsilyl)methyl (meth)acrylate, deuterated
(tributylsilyl)methyl (meth)acrylate, deuterated
(tri-sec-butylsilyl)methyl (meth)acrylate, deuterated
(triisobutylsilyl)methyl (meth)acrylate, deuterated
(sec-butylmethylsilyl)methyl (meth)acrylate, deuterated
(sec-butyldimethylsilyl)methyl (meth)acrylate, deuterated
(dimethylpropylsilyl)methyl (meth)acrylate, deuterated
(monomethyldipropylsilyl)methyl (meth)acrylate, deuterated
(methylethylpropylsilyl)methyl (meth)acrylate, deuterated
bis(trimethylsilyl)methyl (meth)acrylate, deuterated
tris(trimethylsilyl)methyl (meth)acrylate, deuterated
(pentamethyldisilyl)methyl (meth)acrylate, deuterated
tris(trimethylsiloxy)methyl (meth)acrylate, deuterated
tris(trimethylsiloxy)propyl (meth)acrylate), deuterated
(pentamethyldisiloxy)methyl (meth)acrylate, deuterated
(pentamethyldisoloxy)propyl (meth)acrylate, deuterated
(trimethoxysilyl)propyl (meth)acrylate and deuterated
(triethoxysilyl)propyl (meth)acrylate; wherein silyl acrylate block
modifying monomer is ethylene; and, wherein the deuterated silyl
acrylate block modifying monomer is selected from a deuterated
ethylene.
8. The copolymer composition of claim 7, wherein the poly(acrylate)
block includes >95 wt % of acrylate monomer derived units,
wherein the acrylate monomer is methyl (meth)acrylate; and, wherein
the poly(silyl acrylate) block includes >95 wt % of silyl
acrylate monomer derived units, wherein the silyl acrylate monomer
is (trimethylsilyl)methyl methacrylate.
9. The copolymer composition of claim 8, wherein the copolymer
composition contains 5 to 30 wt % antioxidant (based on the weight
of the block copolymer).
10. A method comprising: providing a substrate; providing a
copolymer composition according to claim 1; applying a film of the
copolymer composition to the substrate; optionally, baking the
film; annealing the film, leaving a pattern of poly(acrylate)
domains and poly(silyl acrylate) domains; treating the annealed
film to remove the poly(acrylate) domains from the annealed film
and to convert the poly(silyl acrylate) domains in the annealed
film to SiO.sub.x.
11. A copolymer composition, comprising: a block copolymer having a
poly(acrylate) block and a poly(silyl acrylate) block; wherein the
block copolymer exhibits a number average molecular weight,
M.sub.N, of 1 to 1,000 kg/mol; wherein the block copolymer exhibits
a polydispersity, PD, of 1 to 2; and, wherein the block copolymer
contains .ltoreq.75 wt % of a poly(methyl
methacrylate)-block-poly((trimethylsilyl)methyl methacrylate)
diblock copolymer.
12. The copolymer composition of claim 11, wherein the block
copolymer contains <0.001 wt % of a poly(methyl
methacrylate)-block-poly((trimethylsilyl)methyl methacrylate)
diblock copolymer.
Description
[0001] The present invention relates to the field of self
assembling block copolymers. In particular, the present invention
is directed to a specific copolymer composition including a block
copolymer having a poly(acrylate) block and a poly(silyl acrylate)
block.
[0002] Some block copolymers, consisting of two or more distinct
homopolymers joined end to end, are known self-assemble into
periodic micro domains having typical dimensions of 10 nanometers
to 50 nanometers (nm). The possibility of using such micro domains
to pattern surfaces has attracted increasing interest because of
the expense and difficulty of patterning in nanoscale dimensions
(especially sub-45 nm) using optical lithography.
[0003] Controlling the lateral placement of the block copolymer
micro domains on the substrates continues to be a challenge,
however. This problem has been previously addressed using
lithographically predefined topographic and/or chemical patterning
of the substrate. Previous studies have demonstrated that self
assembled block copolymer micro domains in form of lamellae can be
directed to follow chemical patterning of the substrate, yielding
periodicities close to those of the chemical prepatterns. Other
studies have shown that by controlling the surface wetting
properties of the block copolymer on the bottom and side walls of a
topographic prepattern, the lamellae can be directed to follow the
topographic prepattern. The lamellae formed line/space patterns of
smaller dimensions than the substrate prepattern, subdividing the
topographic prepattern into a higher frequency line pattern; that
is, a line pattern having a smaller pitch. One limitation of block
copolymer patterning is the propensity of the patterns to form
everywhere on the pre-pattern surface, for topographic and/or
chemical guiding prepatterns.
[0004] The ability to shrink the size of various features on a
given substrate (e.g., gates in field effect transistors) is
currently limited by the wavelength of light used to expose
photoresists (i.e., 193 nm). These limitations create a significant
challenge for the fabrication of features having a critical
dimension (CD) of <50 nm. The use of conventional block
copolymers present difficulties in orientation control and long
range ordering during the self assembly process. Moreover, such
block copolymers frequently provide inadequate etch resistance for
subsequent processing steps.
[0005] Takenaka, et al..sup.1 investigated the use of diblock
copolymer for directed self assembly. Specifically, Takenaka, et
al. demonstrated the directed self assembly down to sub 10 nm half
pitch using a poly(styrene)-b-poly(dimethyl siloxane) diblock
copolymer with a molecular weight of 15.8 kg/mol; a heterogeneity
index of 1.03; and, a poly(styrene) volume fraction of 0.74
poly(styrene); wherein the diblock copolymer film was annealed in
vacuum at 170.degree. C. for 24 hours. .sup.1Takenaka, et al,
Formation of long-range stripe patterns with sub-10-nm half-pitch
from directed self-assembly of block copolymer, JOURNAL OF POLYMER
SCIENCE: PART B, Polymer Physics, vol. 48, pp. 2297-2301
(2010).
[0006] Notwithstanding, there remains a need for new copolymer
compositions for use in patterning substrates. In particular, there
remains a need for new copolymer compositions that enable
patterning on intermediate length scales (e.g., 20 to 40 nm) and
that preferably exhibit a fast annealing profile with low defect
formation.
[0007] The present invention provides a copolymer composition,
comprising: a block copolymer having a poly(acrylate) block and a
poly(silyl acrylate) block; and, an antioxidant; wherein the block
copolymer exhibits a number average molecular weight, M.sub.N, of 1
to 1,000 kg/mol; wherein the copolymer composition contains
.gtoreq.2 wt % antioxidant (based on the weight of the block
copolymer); and, wherein the block copolymer exhibits a
polydispersity, PD, of 1 to 2.
[0008] The present invention provides a method comprising:
providing a substrate; providing a copolymer composition of the
present invention; applying a film of the copolymer composition to
the substrate; optionally, baking the film; annealing the film,
leaving a pattern of poly(acrylate) domains and poly(silyl
acrylate) domains; treating the annealed film to remove the
poly(acrylate) domains from the annealed film and to convert the
poly(silyl acrylate) domains in the annealed film to SiO.sub.x.
[0009] The present invention provides a copolymer composition,
comprising: a block copolymer having a poly(acrylate) block and a
poly(silyl acrylate) block; wherein the block copolymer exhibits a
number average molecular weight, M.sub.N, of 1 to 1,000 kg/mol;
wherein the block copolymer exhibits a polydispersity, PD, of 1 to
2; and, wherein the block copolymer contains .ltoreq.75 wt % of a
poly(methyl methacrylate)-block-poly((trimethylsilyl)methyl
methacrylate) diblock copolymer.
[0010] The present invention provides a copolymer composition,
comprising: a block copolymer having a poly(acrylate) block and a
poly(silyl acrylate) block; wherein the block copolymer exhibits a
number average molecular weight, M.sub.N, of 1 to 1,000 kg/mol;
wherein the block copolymer exhibits a polydispersity, PD, of 1 to
2; and, wherein the block copolymer contains .ltoreq.0.001 wt % of
a poly(methyl methacrylate)-block-poly((trimethylsilyl)methyl
methacrylate) diblock copolymer.
DETAILED DESCRIPTION
[0011] When applied to the surface of a substrate, the copolymer
composition of the present invention exhibits an improved
capability to anneal at a given processing temperature to a low
defect structure compared to that obtained using a conventional
silicon containing polymers, such as PS-b-PDMS. Moreover, the
incorporation of an inorganic moiety in the poly(silyl acrylate)
domain of the copolymer composition of the present invention is
convertible to an etch resistant species (e.g., a mask) upon
processing of the deposited copolymer composition to remove the
organic components. The copolymer composition of the present
invention provides significant value for enabling thermal
processing in directed self assembly applications used to form
periodic nanostructures, such as line/space patterns on silicon
containing substrates, in, for example, the 20-40 nm range.
[0012] The term "PAcr-b-PSiAcr block copolymer" used herein and in
the appended claims is short hand for a
poly(acrylate)-block-poly(silyl acrylate); wherein the
poly(acrylate) block includes residues from at least one of an
acrylate monomer, a deuterated acrylate monomer, an acrylate block
modifying monomer and a deuterated acrylate block modifying
monomer; and, wherein the poly(silyl acrylate) block includes
residues from at least one of a silyl acrylate monomer, a
deuterated silyl acrylate monomer, a silyl acrylate block modifying
monomer and a deuterated silyl acrylate block modifying
monomer.
[0013] The term "deuterated acrylate monomer" used herein and in
the appended claims is an acrylate monomer in which at least one
hydrogen has been replaced with deuterium.
[0014] The term "deuterated acrylate block modifying monomer" used
herein and in the appended claims is an acrylate modifying monomer
in which at least one hydrogen has been replaced with
deuterium.
[0015] The term "deuterated silyl acrylate monomer" used herein and
in the appended claims is a silyl acrylate monomer in which at
least one hydrogen has been replaced with deuterium.
[0016] The term "deuterated silyl acrylate block modifying monomer"
used herein and in the appended claims is a silyl acrylate
modifying monomer in which at least one hydrogen has been replaced
with deuterium.
[0017] The terms "(trimethylsilyl)methyl methacrylate" and "TMSMMA"
used herein and in the appended claims refers to a monomer having
the following molecular structure:
##STR00001##
[0018] The term "M.sub.N-BCP" used herein and in the appended
claims in reference to a block copolymer of the present invention
is the number average molecular weight of the block copolymer
determined according to the method used herein in the Examples.
[0019] The term "M.sub.W-BCP" used herein and in the appended
claims in reference to a block copolymer of the present invention
is the weight average molecular weight of the block copolymer
determined according to the method used herein in the Examples.
[0020] The term "PD.sub.BCP" used herein and in the appended claims
in reference to a block copolymer of the present invention is the
polydispersity of the block copolymer determined according to the
following equation:
PD BCP = M W - BCP M N - BCP . ##EQU00001##
[0021] The term "Wf.sub.PAcr" used herein and in the appended
claims in reference to a block copolymer of the present invention
is the weight percent of the poly(acrylate) block in the block
copolymer.
[0022] The term "Wf.sub.PSiAcr" used herein and in the appended
claims in reference to a block copolymer of the present invention
is the weight percent of the poly(silyl acrylate) block in the
block copolymer.
[0023] Block copolymers are polymers that are synthesized from two
or more different monomers and exhibit two or more polymeric chain
segments that are chemically different, but yet, are covalently
bound to one another. Diblock copolymers are a special class of
block copolymers derived from two different monomers (e.g., A and
B) and having a structure comprising a polymeric block of A
residues covalently bound to a polymeric block of B residues (e.g.,
AAAAA-BBBBB).
[0024] The block copolymer used in the copolymer composition of the
present invention include block copolymers having at least two
different blocks; wherein one of the blocks is a poly(acrylate)
block and one of the blocks is a poly(silyl acrylate) block. The
block copolymers used in the copolymer composition of the present
invention optionally contain one or more other blocks (e.g., a
triblock copolymer).
[0025] Preferably, the block copolymer used in the copolymer
composition of the present invention is a PAcr-b-PSiAcr diblock
copolymer comprising domains of poly(acrylate) block and poly(silyl
acrylate) block; wherein the block copolymer exhibits a film pitch,
L.sub.o, of 10 to 100 nm (preferably 14 to 60 nm; most preferably
20 to 40 nm) when deposited on a substrate under the conditions set
forth herein in the Examples.
[0026] Preferably, the block copolymer used in the copolymer
composition of the present invention is a PAcr-b-PSiAcr diblock
copolymer comprising domains of poly(acrylate) and poly(silyl
acrylate); wherein the block copolymer exhibits a number average
molecular weight, M.sub.N-BCP, of 1 to 1,000 kg/mol (preferably 10
to 500 kg/mol; more preferably 15 to 300 kg/mol; still more
preferably 15 to 100 kg/mol; most preferably 20 to 60 kg/mol); and,
wherein the block copolymer exhibits a polydispersity, PD.sub.BCP,
of 1 to 3 (preferably 1 to 2; most preferably 1 to 1.2).
[0027] Preferably, the block copolymer used in the copolymer
composition of the present invention is a PAcr-b-PSiAcr diblock
copolymer comprising domains of poly(acrylate) and poly(silyl
acrylate); wherein the diblock copolymer has a poly(acrylate)
weight fraction, Wf.sub.PAcr, of 0.69 to 0.83 (preferably 0.69 to
0.80; most preferably 0.70 to 0.75); and wherein the diblock
copolymer has a number average molecular weight, M.sub.N, of 10 to
1,000 kg/mol (preferably 15 to 200 kg/mol; more preferably 15 to
100 kg/mol; most preferably 20 to 60 kg/mol). Diblock copolymers of
the present invention having a Wf.sub.PAcr of 0.69 to 0.83 and a
number average molecular weight, M.sub.N, of 10 to 1,000 kg/mol
tend to exhibit cylindrical poly(silyl acrylate) domains that
microphase separate from the poly(acrylate) domains. Given the
teachings provided herein, one of ordinary skill in the art will be
able to deposit a copolymer composition of the present invention
containing such PAcr-b-PSiAcr diblock copolymers, wherein
cylindrical poly(silyl acrylate) domains in the deposited copolymer
composition will self assemble to orient themselves with their axes
of symmetry parallel to the surface of the substrate, perpendicular
to the surface of the substrate or a combination of parallel and
perpendicular to the surface of the substrate, through the
selection and control of the film deposition conditions, for
example: (a) the substrate's surface energy (i.e., by pretreating
the surface of the substrate with an interposing material), (b) the
thickness of the film of copolymer composition deposited, (c) the
bake profile of the deposited copolymer composition (i.e., bake
temperature and bake time) and (d) the anneal profile of the
deposited copolymer composition (i.e., anneal temperature and
anneal time).
[0028] Preferably, the block copolymer of the present invention is
a PAcr-b-PSiAcr diblock copolymer comprising domains of
poly(acrylate) and poly(silyl acrylate); wherein the diblock
copolymer has a poly(acrylate) weight fraction, Wf.sub.PAcr, of
0.39 to <0.69 (preferably 0.44 to 0.64; most preferably 0.49 to
0.59); and wherein the diblock copolymer has a number average
molecular weight, M.sub.N, of 10 to 1,000 kg/mol (preferably 15 to
200 kg/mol; more preferably 15 to 100 kg/mol; most preferably 20 to
60 kg/mol). Diblock copolymers of the present invention having a
Wf.sub.PAcr of 0.39 to <0.69 and a number average molecular
weight, M.sub.N, of 10 to 1,000 kg/mol tend to exhibit microphase
separated poly(acrylate) and poly(silyl acrylate) lamellar domains.
Given the teachings provided herein, one of ordinary skill in the
art will be able to deposit a copolymer composition of the present
invention containing such PAcr-b-PSiAcr diblock copolymers, wherein
lamellar domains in the deposited copolymer composition will self
assemble to orient themselves with their axes of symmetry parallel
to the surface of the substrate, perpendicular to the surface of
the substrate or a combination of parallel and perpendicular to the
surface of the substrate, through the selection and control of the
film deposition conditions, for example: (a) the substrate's
surface energy (i.e., by pretreating the surface of the substrate
with an interposing material), (b) the thickness of the film of
copolymer composition deposited, (c) the bake profile of the
deposited copolymer composition (i.e., bake temperature and bake
time) and (d) the anneal profile of the deposited copolymer
composition (i.e., anneal temperature and anneal time).
[0029] Preferably, the block copolymer used in the copolymer
composition of the present invention is a PAcr-b-PSiAcr diblock
copolymer comprising domains of poly(acrylate) and poly(silyl
acrylate); wherein the diblock copolymer has a poly(acrylate)
weight fraction, Wf.sub.PAcr, of 0.23 to <0.39 (preferably 0.26
to 0.34; most preferably 0.27 to 0.30); and wherein the diblock
copolymer has a number average molecular weight, M.sub.N, of 10 to
1,000 kg/mol (preferably 15 to 200 kg/mol; more preferably 15 to
100 kg/mol; most preferably 20 to 60 kg/mol). Diblock copolymers of
the present invention having a Wf.sub.PAcr of 0.23 to <0.39 and
a number average molecular weight, M.sub.N, of 10 to 1,000 kg/mol
tend to exhibit cylindrical poly(acrylate) domains that microphase
separate from the poly(silyl acrylate). Given the teachings
provided herein, one of ordinary skill in the art will be able to
deposit a copolymer composition of the present invention containing
such PAcr-b-PSiAcr diblock copolymers, wherein cylindrical
poly(acrylate) domains in the deposited copolymer composition will
self assemble to orient themselves with their axes of symmetry
parallel to the surface of the substrate, perpendicular to the
surface of the substrate or a combination of parallel and
perpendicular to the surface of the substrate, through the
selection and control of the film deposition conditions, for
example: (a) the substrate's surface energy (i.e., by pretreating
the surface of the substrate with an interposing material), (b) the
thickness of the film of copolymer composition deposited, (c) the
bake profile of the deposited copolymer composition (i.e., bake
temperature and bake time) and (d) the anneal profile of the
deposited copolymer composition (i.e., anneal temperature and
anneal time).
[0030] Preferably, the poly(acrylate)-b-poly(silyl acrylate) block
copolymers have a poly(acrylate) block; wherein the poly(acrylate)
block includes residues from at least one of an acrylate monomer, a
deuterated acrylate monomer, an acrylate block modifying monomer
and a deuterated acrylate block modifying monomer; and, wherein the
poly(acrylate) block includes >75 wt % (more preferably, >90
wt %; most preferably, >95 wt %) of acrylate monomer derived
units.
[0031] Preferably, the acrylate monomer is selected from the group
consisting of aryl (alkyl)acrylate (e.g., phenyl acrylate, phenyl
methacrylate); alkyl (alkyl)acrylate (e.g., methyl acrylate, methyl
methacrylate); halogenated aryl (alkyl)acrylate (e.g., chlorophenyl
acrylate, chlorophenyl methacrylate); halogenated alkyl
(alkyl)acrylate (e.g., fluoropropyl acrylate, fluoropropyl
methacrylate) and, combinations thereof. More preferably, the
acrylate monomer is selected from the group consisting of
C.sub.6-14 aryl (C.sub.1-5 alkyl)acrylate; C.sub.1-5 alkyl
(C.sub.1-5 alkyl)acrylate. Still more preferably, the acrylate
monomer is selected from the group consisting of butyl
(meth)acrylate, propyl (meth)acrylate), ethyl (meth)acrylate,
methyl (meth)acrylate. Most preferably, the acrylate monomer is
methyl methacrylate.
[0032] Preferably, the deuterated acrylate monomer is selected from
the group consisting of deuterated aryl (alkyl)acrylate (e.g.,
deuterated phenyl acrylate, deuterated phenyl methacrylate);
deuterated alkyl (alkyl)acrylate (e.g., deuterated methyl acrylate,
deuterated methyl methacrylate); deuterated halogenated aryl
(alkyl)acrylate (e.g., deuterated chlorophenyl acrylate, deuterated
chlorophenyl methacrylate); deuterated halogenated alkyl
(alkyl)acrylate (e.g., deuterated fluoropropyl acrylate, deuterated
fluoropropyl methacrylate) and, combinations thereof. More
preferably, the deuterated acrylate monomer is selected from the
group consisting of deuterated C.sub.6-14 aryl (C.sub.1-5
alkyl)acrylate; deuterated C.sub.1-5 alkyl (C.sub.1-5
alkyl)acrylate. Still more preferably, the deuterated acrylate
monomer is selected from the group consisting of deuterated butyl
(meth)acrylate, deuterated propyl (meth)acrylate), deuterated ethyl
(meth)acrylate, deuterated methyl (meth)acrylate. Most preferably,
the deuterated acrylate monomer is deuterated methyl
methacrylate.
[0033] Preferably, the acrylate block modifying monomer is selected
from the group consisting of an alkene and a cycloalkene. More
preferably, the acrylate block modifying monomer is selected from a
C.sub.1-5 alkene and a C.sub.3-7 cycloalkene. Most preferably, the
acrylate block modifying monomer is ethylene.
[0034] Preferably, the deuterated acrylate block modifying monomer
is selected from the group consisting of a deuterated alkene and a
deuterated cycloalkene. More preferably, the deuterated acrylate
block modifying monomer is selected from a deuterated C.sub.1-5
alkene and deuterated a C.sub.3-7 cycloalkene. Most preferably, the
deuterated acrylate block modifying monomer is deuterated
ethylene.
[0035] Preferably, the poly(acrylate)-b-poly(silyl acrylate) block
copolymers have a poly(silyl acrylate) block; wherein the
poly(silyl acrylate) block includes residues from at least one of a
silyl acrylate monomer, a deuterated silyl acrylate monomer, a
silyl acrylate block modifying monomer and a deuterated silyl
acrylate block modifying monomer; and, wherein the poly(silyl
acrylate) block includes >75 wt % (more preferably, >90 wt %;
most preferably, >95 wt %) of silyl acrylate monomer derived
units.
[0036] Preferably, the silyl acrylate monomer is according to the
following formula
(R.sup.1(R.sup.2)(R.sup.3)Si).sub.rR.sup.4.sub.xOOCC(R.sup.5).dbd.CR.sup-
.6.sub.2
wherein each R.sup.1, R.sup.2 and R.sup.3 is independently selected
from the group consisting of a C.sub.1-18 alkyl group, a
halogenated C.sub.1-18 alkyl group, a silylated C.sub.1-18 alkyl
group, a silylated halogenated C.sub.1-18 alkyl group, an oxy
C.sub.1-18 alkyl group, an oxy silylated C.sub.1-18 alkyl group, an
oxy silylated halogenated C.sub.1-18 alkyl group, a C.sub.6-14 aryl
group, a halogenated C.sub.6-14 aryl group, an oxy C.sub.6-14 aryl
group, a silylated C.sub.6-14 aryl group, an oxy silylated
C.sub.6-14 aryl group, an oxy silylated halogenated C.sub.6-14 aryl
group, a C.sub.1-18 arylalkyl group, a halogenated C.sub.1-18
arylalkyl group, an oxy C.sub.1-18 arylalkyl group, a silylated
C.sub.1-18 arylalkyl group, a silylated halogenated C.sub.1-18
arylalkyl group, an oxy silylated C.sub.1-18 arylalkyl group, an
oxy silylated halogenated C.sub.1-18 arylalkyl group, a C.sub.6-14
alkylaryl group, a halogenated C.sub.6-14 alkylaryl group, an oxy
C.sub.6-14 alkylaryl group, a silylated C.sub.6-14 alkylaryl group,
an oxy silylated C.sub.6-14 alkylaryl group and an oxy silylated
halogenated C.sub.6-14 alkylaryl group (preferably, a C.sub.1-6
alkyl group, a silylated C.sub.1-6 alkyl group, an oxy C.sub.1-6
alkyl group, an oxy silylated C.sub.1-6 alkyl group, a C.sub.6-10
aryl group, an oxy C.sub.6-10 aryl group, a silylated C.sub.6-10
aryl group, an oxy silylated C.sub.6-10 aryl group, a C.sub.1-10
arylalkyl group, an oxy C.sub.1-10 arylalkyl group, a silylated
C.sub.1-10 arylalkyl group, an oxy silylated C.sub.1-10 arylalkyl
group, a C.sub.6-10 alkylaryl group, an oxy C.sub.6-10 alkylaryl
group, a silylated C.sub.6-10 alkylaryl group and an oxy silylated
C.sub.6-10 alkylaryl group; more preferably, a C.sub.1-3 alkyl
group; most preferably, a methyl group); wherein r is selected from
the group consisting of 0, 1, 2 and 3 (preferably, 1, 2 and 3; more
preferably, r is 1); wherein R.sup.4 is selected from the group
consisting of a C.sub.1-10 alkyl, a halogenated C.sub.1-10 alkyl
group, a silylated C.sub.1-10 alkyl group, a silylated halogenated
C.sub.1-10 alkyl group, an oxy silylated C.sub.1-10 alkyl group and
a halogenated oxy silylated C.sub.1-10 alkyl group (preferably, a
C.sub.1-3 alkyl group and a halogenated C.sub.1-3 alkyl group; more
preferably, a C.sub.1-3 alkyl group; most preferably a methyl
group); wherein x is selected from the group consisting of 0 and 1
(preferably, x is 1); wherein R.sup.5 is selected from the group
consisting of a hydrogen, a halogen, a C.sub.1-3 alkyl group, a
silylated C.sub.1-3 alkyl group and a halogenated C.sub.1-3 alkyl
group (preferably, a hydrogen and a methyl group; more preferably,
a methyl group); wherein each R.sup.6 is independently selected
from a hydrogen, a halogen, a silyl methyl group, a methyl group
and a halogenated methyl group (preferably, a hydrogen and a methyl
group; more preferably, a hydrogen); and, wherein the silyl
acrylate monomer includes at least one Si atom. More preferably,
the silyl acrylate monomer is selected from the group consisting of
(trimethylsilyl)methyl (meth)acrylate; (triethylsilyl)methyl
(meth)acrylate; (tripropylsilyl)methyl (meth)acrylate;
(triisopropylsilyl)methyl (meth)acrylate; (tributylsilyl)methyl
(meth)acrylate; (tri-sec-butylsilyl)methyl (meth)acrylate;
(triisobutylsilyl)methyl (meth)acrylate;
(sec-butylmethylsilyl)methyl (meth)acrylate;
(sec-butyldimethylsilyl)methyl (meth)acrylate;
(dimethylpropylsilyl)methyl (meth)acrylate;
(monomethyldipropylsilyl)methyl (meth)acrylate;
(methylethylpropylsilyl)methyl (meth)acrylate;
bis(trimethylsilyl)methyl (meth)acrylate;
tris(trimethylsilyl)methyl (meth)acrylate;
(pentamethyldisilyl)methyl (meth)acrylate;
tris(trimethylsiloxy)methyl (meth)acrylate;
tris(trimethylsiloxy)propyl (meth)acrylate);
(pentamethyldisiloxy)methyl (meth)acrylate;
(pentamethyldisiloxy)propyl (meth)acrylate; (trimethoxysilyl)propyl
(meth)acrylate; and, (triethoxysilyl)propyl (meth)acrylate. Most
preferably, the silyl acrylate monomer is (trimethylsilyl)methyl
methacrylate.
[0037] Preferably, the deuterated silyl acrylate monomer is
according to the following formula
(R.sup.7(R.sup.8)(R.sup.9)Si).sub.tR.sup.10.sub.yOOCC(R.sup.11).dbd.CR.s-
up.12.sub.2
wherein each R.sup.7, R.sup.8 and R.sup.9 is independently selected
from a C.sub.1-18 alkyl group, a halogenated C.sub.1-18 alkyl
group, a silylated C.sub.1-18 alkyl group, a silylated halogenated
C.sub.1-18 alkyl group, an oxy C.sub.1-18 alkyl group, an oxy
silylated C.sub.1-18 alkyl group, an oxy silylated halogenated
C.sub.1-18 alkyl group, a C.sub.6-14 aryl group, a halogenated
C.sub.6-14 aryl group, an oxy C.sub.6-14 aryl group, a silylated
C.sub.6-14 aryl group, an oxy silylated C.sub.6-14 aryl group, an
oxy silylated halogenated C.sub.6-14 aryl group, a C.sub.1-18
arylalkyl group, a halogenated C.sub.1-18 arylalkyl group, an oxy
arylalkyl group, a silylated C.sub.1-18 arylalkyl group, a
silylated halogenated C.sub.1-18 arylalkyl group, an oxy silylated
C.sub.1-18 arylalkyl group, an oxy silylated halogenated C.sub.1-18
arylalkyl group, a C.sub.6-14 alkylaryl group, a halogenated
C.sub.6-14 alkylaryl group, an oxy C.sub.6-14 alkylaryl group, a
silylated C.sub.6-14 alkylaryl group, an oxy silylated C.sub.6-14
alkylaryl group, an oxy silylated halogenated C.sub.6-14 alkylaryl
group, a deuterated C.sub.1-18 alkyl group, a deuterated
halogenated C.sub.1-18 alkyl group, a deuterated silylated
C.sub.1-18 alkyl group, a deuterated silylated halogenated
C.sub.1-18 alkyl group, a deuterated oxy C.sub.1-18 alkyl group, a
deuterated oxy silylated C.sub.1-18 alkyl group, a deuterated oxy
silylated halogenated C.sub.1-18 alkyl group, a deuterated
C.sub.6-14 aryl group, a deuterated halogenated C.sub.6-14 aryl
group, a deuterated oxy C.sub.6-14 aryl group, a deuterated
silylated C.sub.6-14 aryl group, a deuterated oxy silylated
C.sub.6-14 aryl group, a deuterated oxy silylated halogenated
C.sub.6-14 aryl group, a deuterated C.sub.1-18 arylalkyl group, a
deuterated halogenated C.sub.1-18 arylalkyl group, a deuterated oxy
C.sub.1-18 arylalkyl group, a deuterated silylated C.sub.1-18
arylalkyl group, a deuterated silylated halogenated C.sub.1-18
arylalkyl group, a deuterated oxy silylated C.sub.1-18 arylalkyl
group, a deuterated oxy silylated halogenated C.sub.1-18 arylalkyl
group, a deuterated C.sub.6-14 alkylaryl group, a deuterated
halogenated C.sub.6-14 alkylaryl group, a deuterated oxy C.sub.6-14
alkylaryl group, a deuterated silylated C.sub.6-14 alkylaryl group,
a deuterated oxy silylated C.sub.6-14 alkylaryl group and a
deuterated oxy silylated halogenated C.sub.6-14 alkylaryl group
(preferably, a C.sub.1-6 alkyl group, a silylated C.sub.1-6 alkyl
group, an oxy C.sub.1-6 alkyl group, an oxy silylated C.sub.1-6
alkyl group, a C.sub.6-10 aryl group, an oxy C.sub.6-10 aryl group,
a silylated C.sub.6-10 aryl group, an oxy silylated C.sub.6-10 aryl
group, a C.sub.1-10 arylalkyl group, an oxy C.sub.1-10 arylalkyl
group, a silylated C.sub.1-10 arylalkyl group, an oxy silylated
C.sub.1-10 arylalkyl group, a C.sub.6-10 alkylaryl group, an oxy
C.sub.6-10 alkylaryl group, a silylated C.sub.6-10 alkylaryl group,
an oxy silylated C.sub.6-10 alkylaryl group, a deuterated C.sub.1-6
alkyl group, a deuterated silylated C.sub.1-6 alkyl group, a
deuterated oxy C.sub.1-6 alkyl group, a deuterated oxy silylated
C.sub.1-6 alkyl group, a deuterated C.sub.6-10 aryl group, a
deuterated oxy C.sub.6-10 aryl group, a deuterated silylated
C.sub.6-10 aryl group, a deuterated oxy silylated C.sub.6-10 aryl
group, a deuterated C.sub.1-10 arylalkyl group, a deuterated oxy
C.sub.1-10 arylalkyl group, a deuterated silylated C.sub.1-10
arylalkyl group, a deuterated oxy silylated C.sub.1-10 arylalkyl
group, a deuterated C.sub.6-10 alkylaryl group, a deuterated oxy
C.sub.6-10 alkylaryl group, a deuterated silylated C.sub.6-10
alkylaryl group and a deuterated oxy silylated C.sub.6-10 alkylaryl
group; more preferably, a C.sub.1-3 alkyl group and a deuterated
C.sub.1-3 alkyl group; most preferably, a methyl group and a
deuterated methyl group); wherein t is selected from the group
consisting of 0, 1, 2 and 3 (preferably, 1, 2 and 3; more
preferably, t is 1); wherein R.sup.10 is selected from the group
consisting of a C.sub.1-10 alkyl, a halogenated C.sub.1-10 alkyl
group, a silylated C.sub.1-10 alkyl group, a silylated halogenated
C.sub.1-10 alkyl group, an oxy silylated C.sub.1-10 alkyl group, a
halogenated oxy silylated C.sub.1-10 alkyl group, a deuterated
C.sub.1-10 alkyl, a deuterated halogenated C.sub.1-10 alkyl group,
a deuterated silylated C.sub.1-10 alkyl group, a deuterated
silylated halogenated C.sub.1-10 alkyl group, a deuterated oxy
silylated C.sub.1-10 alkyl group and a deuterated halogenated oxy
silylated C.sub.1-10 alkyl group (preferably, a C.sub.1-3 alkyl
group and a deuterated C.sub.1-3 alkyl group; more preferably, a
C.sub.1-3 alkyl group; most preferably a methyl group); wherein y
is 0 or 1 (preferably, y is 1); wherein R.sup.11 is selected from
the group consisting of a hydrogen, a deuterium, a halogen, a
C.sub.1-3 alkyl group, a deuterated C.sub.1-3 alkyl group, a
silylated C.sub.1-3 alkyl group, a deuterated silylated C.sub.1-3
alkyl group, a halogenated C.sub.1-3 alkyl group and a deuterated
halogenated C.sub.1-3 alkyl group (preferably, a hydrogen, a
deuterium, a methyl group and a deuterated methyl group; more
preferably, a methyl group); wherein each R.sup.12 is independently
selected from a hydrogen, a deuterium, a halogen, a silyl methyl
group, a deuterated silyl methyl group, a methyl group, a
deuterated methyl group, a halogenated methyl group and a
deuterated halogenated methyl group (preferably, a hydrogen, a
deuterium, a methyl group and a deuterated methyl group; more
preferably, a hydrogen); wherein the deuterated silyl acrylate
monomer contains at least one Si atom; and, wherein the deuterated
silyl acrylate monomer contains at least one deuterium. More
preferably, the deuterated silyl acrylate monomer is selected from
the group consisting of deuterated (trimethylsilyl)methyl
(meth)acrylate; deuterated (triethylsilyl)methyl (meth)acrylate;
deuterated (tripropylsilyl)methyl (meth)acrylate; deuterated
(triisopropylsilyl)methyl (meth)acrylate; deuterated
(tributylsilyl)methyl (meth)acrylate; deuterated
(tri-sec-butylsilyl)methyl (meth)acrylate; deuterated
(triisobutylsilyl)methyl (meth)acrylate; deuterated
(sec-butylmethylsilyl)methyl (meth)acrylate; deuterated
(sec-butyldimethylsilyl)methyl (meth)acrylate; deuterated
(dimethylpropylsilyl)methyl (meth)acrylate; deuterated
(monomethyldipropylsilyl)methyl (meth)acrylate; deuterated
(methylethylpropylsilyl)methyl (meth)acrylate; deuterated
bis(trimethylsilyl)methyl (meth)acrylate; deuterated
tris(trimethylsilyl)methyl (meth)acrylate; deuterated
(pentamethyldisilyl)methyl (meth)acrylate; deuterated
tris(trimethylsiloxy)methyl (meth)acrylate; deuterated
tris(trimethylsiloxy)propyl (meth)acrylate); deuterated
(pentamethyldisiloxy)methyl (meth)acrylate; deuterated
(pentamethyldisoloxy)propyl (meth)acrylate; deuterated
(trimethoxysilyl)propyl (meth)acrylate; and, deuterated
(triethoxysilyl)propyl (meth)acrylate. Most preferably, the
deuterated silyl acrylate monomer is deuterated
(trimethylsilyl)methyl methacrylate.
[0038] Preferably, the silyl acrylate block modifying monomer is
selected from the group consisting of an alkene and a cycloalkene.
More preferably, the silyl acrylate block modifying monomer is
selected from a C.sub.1-5 alkene and a C.sub.3-7 cycloalkene. Most
preferably, the silyl acrylate block modifying monomer is
ethylene.
[0039] Preferably, the deuterated silyl acrylate block modifying
monomer is selected from the group consisting of a deuterated
alkene and a deuterated cycloalkene. More preferably, the
deuterated silyl acrylate block modifying monomer is selected from
a deuterated C.sub.1-5 alkene and deuterated a C.sub.3-7
cycloalkene. Most preferably, the deuterated silyl acrylate block
modifying monomer is deuterated ethylene.
[0040] Preferably, the copolymer composition of the present
invention contains .gtoreq.2 wt % antioxidant (based on the weight
of the PAcr-b-PSiAcr block copolymer). More preferably, the
copolymer composition contains 2 to 30 wt % antioxidant (based on
the weight of the PAcr-b-PSiAcr block copolymer). Still more
preferably, the copolymer composition contains 5 to 30 wt %
antioxidant (based on the weight of the PAcr-b-PSiAcr block
copolymer). Still more preferably, the copolymer composition
contains 10 to 25 wt % antioxidant (based on the weight of the
PAcr-b-PSiAcr block copolymer). Most preferably, the copolymer
composition contains 15 to 25 wt % antioxidant (based on the weight
of the PAcr-b-PSiAcr block copolymer).
[0041] Antioxidant contained in the copolymer composition of the
present invention can be selected from primary antioxidants and
secondary antioxidants. Preferably, the antioxidant is selected
from the group consisting of: antioxidants containing at least one
(preferably at least two; more preferably at least three; most
preferably three to four) 2,6-di-tert-butylphenol moiety;
antioxidants containing at least one (preferably at least two; more
preferably at least three; most preferably three to four) moiety
according to the formula
##STR00002##
antioxidants containing at least one (preferably at least two; most
preferably two) moiety according to the formula
##STR00003##
and, antioxidants containing at least one (preferably at least two;
most preferably two) moiety according to the formula
##STR00004##
and, mixtures thereof. More preferably, the antioxidant is selected
from the group consisting of:
##STR00005## ##STR00006##
and, mixtures thereof. Still more preferably, the antioxidant is
selected from the group consisting of
##STR00007##
and mixtures of
##STR00008##
and one or more other antioxidants. Most preferably, the
antioxidant is
##STR00009##
[0042] Preferably, the antioxidant (or mixture of antioxidants)
contained in the copolymer composition of the present invention has
an average molecular weight of .gtoreq.358 g/mol. More preferably,
the antioxidant (or mixture of antioxidants) contained in the
copolymer composition of the present invention has an average
molecular weight of .gtoreq.600 g/mol. Most preferably, the
antioxidant (or mixture of antioxidants) contained in the copolymer
composition of the present invention has an average molecular
weight of .gtoreq.1,000 g/mol.
[0043] Preferably, the antioxidant (or mixture of antioxidants)
contained in the copolymer composition of the present invention has
an average boiling point temperature measured at 760 mm Hg (101.3
kPa) of >400.degree. C. More preferably, the antioxidant (or
mixture of antioxidants) contained in the copolymer composition of
the present invention has an average boiling point temperature
measured at 760 mm Hg (101.3 kPa) of >500.degree. C. Still more
preferably, the antioxidant (or mixture of antioxidants) contained
in the copolymer composition of the present invention has an
average boiling point temperature measured at 760 mm Hg (101.3 kPa)
of >700.degree. C. Yet still more preferably, the antioxidant
(or mixture of antioxidants) contained in the copolymer composition
of the present invention has an average boiling point temperature
measured at 760 mm Hg (101.3 kPa) of >800.degree. C. Most
preferably, the antioxidant (or mixture of antioxidants) contained
in the copolymer composition of the present invention has an
average boiling point temperature measured at 760 mm Hg (101.3 kPa)
of >1,000.degree. C.
[0044] The copolymer composition of the present invention
optionally further comprises a solvent. Solvents include liquids
that are able to disperse the block copolymer into particles or
aggregates having an average hydrodynamic diameter of less than 50
nm as measured by dynamic light scattering. Preferably, the solvent
used is selected from propylene glycol monomethyl ether acetate
(PGMEA), ethoxyethyl propionate, anisole, ethyl lactate,
2-heptanone, cyclohexanone, amyl acetate, .gamma.-butyrolactone
(GBL), n-methylpyrrolidone (NMP) and toluene. More preferably, the
solvent used is selected from propylene glycol monomethyl ether
acetate (PGMEA) and toluene. Most preferably, the solvent used is
toluene.
[0045] The copolymer composition of the present invention
optionally further comprises an additive. Additives include
additional polymers (including homopolymers and random copolymers);
surfactants; photoacid generators; thermal acid generators;
quenchers; hardeners; adhesion promoters; dissolution rate
modifiers; photocuring agents; photosensitizers; acid amplifiers;
plasticizers; orientation control agents; and cross linking agents.
Preferred additives for use in the copolymer composition of the
present invention include surfactants.
[0046] The method of the present invention preferably comprises:
providing a substrate; providing a copolymer composition of the
present invention; applying a film of the copolymer composition to
the substrate; optionally, baking the film; annealing the film,
leaving a pattern of poly(acrylate) domains and poly(silyl
acrylate) domains; treating the annealed film to remove the
poly(acrylate) domains from the annealed film and to convert the
poly(silyl acrylate) domains in the annealed film to SiO.sub.x.
[0047] Substrates used in the method of the present invention
include any substrate having a surface that can be coated with the
copolymer composition of the present invention. Preferred
substrates include layered substrates. Preferred substrates include
silicon containing substrates (e.g., glass; silicon dioxide;
silicon nitride; silicon oxynitride; silicon containing
semiconductor substrates such as silicon wafers, silicon wafer
fragments, silicon on insulator substrates, silicon on sapphire
substrates, epitaxial layers of silicon on a base semiconductor
foundation, silicon-germanium substrates); plastic; metals (e.g.,
copper, ruthenium, gold, platinum, aluminum, titanium and alloys);
titanium nitride; and non-silicon containing semiconductive
substrates (e.g., non-silicon containing wafer fragments,
non-silicon containing wafers, germanium, gallium arsenide and
indium phosphide). Most preferred substrates are silicon containing
substrates.
[0048] Optionally, the surface of the substrate to be coated with
the copolymer composition of the present invention is pretreated
with an interposing material before the copolymer composition of
the present invention is applied. Preferably, the pretreatment
material acts like a tying layer interposed between the surface of
the substrate and the block copolymer in the copolymer composition
of the present invention to enhance the adhesion between the block
copolymer and the substrate. Preferably, the interposing material
forms a layer selected from an imaging layer and an orientation
control layer.
[0049] Imaging layers suitable for use in the method of the present
invention include, for example, any type of material that can be
patterned or selectively activated. Such materials include, for
example, polymer brushes and a self-assembled monolayers of silane
and siloxane compounds.
[0050] Orientation control layers suitable for use in the method of
the present invention include neutral and non-neutral orientation
control layers. That is, the orientation control layer can form an
interface between the surface of the substrate and the block
copolymer in the copolymer composition of the present invention
that is preferentially wetted by one of poly(acrylate) domains or
poly(silyl acrylate) domains--i.e., a non-neutral orientation
control layer. A neutral orientation control layer refers to a
layer that forms an interface between the surface of the substrate
and the block copolymer in the copolymer composition of the present
invention that is equally wetted by both poly(acrylate) and
poly(silyl acrylate). Neutral orientation control layers preferably
include films prepared by casting a random copolymer that comprises
residues of both acrylate monomers and silyl acrylate monomers
(e.g., poly(methyl methacrylate)-r-(trimethylsilyl)methyl
methacrylate)-OH).
[0051] Preferably, the pretreatment of the substrate before
depositing the copolymer composition of the present invention is
performed to facilitate the guided self assembly of the block
copolymer in the copolymer composition. Specifically, the
pretreatment can facilitate one of the two conventional methods
used for guided self assembly of block copolymer films, namely
graphoepitaxy and chemical epitaxy. In the graphoepitaxy, the
surface of the substrate is prepatterned with topographical
features on the surface of substrate (e.g., trenches, holes) that
operate to direct the self organization of the blocks in the block
copolymer.
[0052] In the chemical epitaxy, the surface of the substrate is
treated with a film that exhibits a compositional pattern, wherein
the affinity between the various parts of the compositional pattern
is different for poly(acrylate) and poly(silyl acrylate). This
chemical affinity difference operates to facilitate the directed
self assembly of the block copolymer in the copolymer
composition.
[0053] Preferably, the interposing layer is formed on the substrate
using a method selected from spin coating, dip coating, roll
coating, spray coating and laminating (most preferably spin
coating). After application of the interposing layer forming
material onto the surface of the substrate, the material is
optionally further processed to remove any residual solvent.
Preferably, the interposing layer is baked at an elevated
temperature (e.g., 70 to 340.degree. C.) for at least 10 seconds to
5 minutes to remove any residual solvent from the interposing
layer. Preferably, the baked interposing layer is rinsed with a
solvent capable of removing any residual unbound interposing layer
material from the surface of the substrate and then rebaked at an
elevated temperature (e.g., 70 to 340.degree. C.) for at least 10
seconds to 5 minutes to remove any residual solvent.
[0054] Applying a film of the copolymer composition of the present
invention to the substrate in the method of the present invention
preferably comprises depositing the copolymer composition onto the
substrate using a method selected from spin coating, dip coating,
roll coating, spray coating and laminating (most preferably spin
coating). After application of the copolymer composition to the
substrate, the deposited copolymer composition is optionally
further processed to remove any residual solvent. Preferably, the
deposited copolymer composition is baked at an elevated temperature
(e.g., 70 to 340.degree. C.) for at least 10 seconds to 5 minutes
to remove any residual solvent from the deposited film of the
copolymer composition.
[0055] Annealing of the deposited film can be done by any annealing
technique, for example, thermal annealing, thermal gradient
annealing and solvent vapor annealing. Preferably, the film is
annealed using a thermal annealing technique. More preferably, the
deposited film is annealed using a thermal annealing technique,
wherein the deposited film is heated at a temperature of 200 to
340.degree. C. (more preferably 200 to 300.degree. C.; most
preferably 225 to 300.degree. C.) for a period of 0.5 minute to 2
days (more preferably 0.5 minute to 2 hours; still more preferably
0.5 minute to 0.5 hour; most preferably 0.5 minute to 5 minutes).
Preferably, the deposited film is annealed using a thermal
annealing technique under a gaseous atmosphere, wherein the gaseous
atmosphere is selected from an atmosphere containing .gtoreq.20 wt
% oxygen and an atmosphere containing <20 wt % oxygen. More
preferably, the deposited film is thermally annealed under a
gaseous atmosphere, wherein the gaseous atmosphere is selected from
a gaseous nitrogen atmosphere and a gaseous argon atmosphere,
wherein the gaseous atmosphere has an oxygen concentration of
.ltoreq.150 ppm (more preferably, .ltoreq.10 ppm; still more
preferably, .ltoreq.7.5 ppm; yet still more preferably, .ltoreq.6.5
ppm; most preferably, .ltoreq.5 ppm). Most preferably, the
deposited film is thermally annealed under a gaseous nitrogen
atmosphere having an oxygen concentration of .ltoreq.100 ppm
(preferably, .ltoreq.7.5 ppm; more preferably, .ltoreq.6.5 ppm;
most preferably, .ltoreq.5 ppm).
[0056] In the method of the present invention, the annealed film is
treated to remove the poly(acrylate) domains in the annealed film
and to convert the poly(silyl acrylate) domains in the annealed
film to SiO.sub.x, providing a product film with a plurality of
voids (i.e., trench shaped voids perpendicular to the surface of
the substrate; cylindrical holes with axes of symmetry
perpendicular to the surface of the substrate; a plurality of
cylindrical SiO.sub.x posts with axes of symmetry perpendicular to
the surface of the substrate). The treatment comprises: exposing
the film to conditions that exhibit differential reactivity towards
the poly(acrylate) in the film relative to the poly(silyl acrylate)
in the film, to facilitate removal of the poly(acrylate) domains
from the annealed film and the conversion of the poly(silyl
acrylate) domains to SiO.sub.x. Preferably, the treatment
comprises: optionally, exposing the annealed film to a halogen
containing plasma (e.g., CF.sub.4) to remove any wetting layer that
formed on the surface of the annealed film; followed by exposing
the annealed film to a reactive plasma or a reactive ion etching
atmosphere to remove the poly(acrylate) domains and to convert the
poly(silyl acrylate) domains to SiO.sub.x. Most preferably, the
treatment comprises: exposing the annealed film to a halogen
containing plasma to remove any wetting layer formed on the
annealed film; and then exposing the annealed film to a reactive
plasma or a reactive ion etching atmosphere, wherein the atmosphere
comprises a plasma composed of a low pressure ionized oxidizing gas
(preferably O.sub.2); wherein the poly(acrylate) domains in the
annealed film is removed and the poly(silyl acrylate) domains in
the annealed film is converted to SiO.sub.x.
[0057] Some embodiments of the present invention will now be
described in detail in the following Examples.
[0058] The following materials were passed through a column packed
with activated A-2 grade alumina before being used in the Examples
herein, namely tetrahydrofuran (99.9% pure available from Aldrich),
styrene (available from Aldrich), and cyclohexane (HPCL grade
available from Fischer). The following materials were passed
through a column packed with basic alumina before being used in the
Examples herein, namely 1,1-diphenyl ethylene (available from
Aldrich) and methyl methacrylate (MMA). All the other materials
used in the Examples herein were commercial materials that were
used as received.
[0059] The film thicknesses reported in the Examples herein were
measured using a NanoSpec/AFT 2100 Film Thickness Measurement tool.
The thickness of the films were determined from the interference of
a white light passed through a diffraction grating. A standard
program called "Polyimide on Silicon" was used to analyze the
component wavelengths (380-780 nm) to determine the film thickness.
The thickness of the film of the deposited block copolymer
composition and the brush layer were measured together as one
polymeric layer. The reported film thickness is the combined
thickness of the deposited block copolymer composition and the
brush layer.
[0060] The number average molecular weight, M.sub.N, and
polydispersity values reported in the Examples were measured by gel
permeation chromatography (GPC) on an Agilent 1100 series LC system
equipped with an Agilent 1100 series refractive index and MiniDAWN
light scattering detector (Wyatt Technology Co.). Samples were
dissolved in HPCL grade THF at a concentration of approximately 1
mg/mL and filtered through at 0.20 .mu.m syringe filter before
injection through the two PLGel 300.times.7.5 mm Mixed C columns (5
mm, Polymer Laboratories, Inc.). A flow rate of 1 mL/min and
temperature of 35.degree. C. were maintained. The columns were
calibrated with narrow molecular weight PS standards (EasiCal PS-2,
Polymer Laboratories, Inc.).
[0061] Proton nuclear magnetic resonance (.sup.1H NMR) spectroscopy
results referred to in the Examples was done on a Varian INOVA 400
MHz NMR spectrometer. Deuterated chloroform was used. A delay time
of 10 seconds was used to ensure complete relaxation of protons for
quantitative integrations. Chemical shifts are reported relative to
tetramethylsilane.
[0062] A PlasmaTherm 790i/reactive ion etch platform was used for
all of the reactive ion etching steps mentioned in the
Examples.
[0063] The film pitch, L.sub.0, for the films reported in the
Examples was measured using image analysis of the SEMS of the films
with ImageJ, a public domain, JAVA based image processing program.
Spatial calibration was first carried out to convert distance in
pixels in the image to distances in nanometers for a given SEM
image. To measure the film pitch, a line was drawn across and
perpendicular to multiple SiO.sub.x cylinders. The film pitch was
calculated by dividing the length of the drawn line by (n-1),
wherein n is the number of SiO.sub.x cylinders crossed by the drawn
line.
Example 1
Preparation of Hydroxyl-Terminated Polystyrene Brush
[0064] Into a 2 liter glass reactor under a nitrogen atmosphere was
added cyclohexane (1,500 g). Styrene (50.34 g) was then added to
the reactor via cannula. The contents of the reactor were then
heated to 40.degree. C. Sec-butyllithium (19.18 g) diluted in
cyclohexane to a concentration of 0.32 M was then rapidly added to
the reactor via cannula, causing the reactor contents to turn
yellow. The contents of the reactor were stirred for 30 minutes.
The contents of the reactor were then cooled to 30.degree. C.
Ethylene oxide (0.73 g) was then transferred into the reactor. The
contents of the reactor were stirred for 15 minutes. Then a 20 mL
of a 1.4 M solution of HCl in methanol was added to the reactor.
The polymer in the reactor was then isolated by precipitating into
isopropanol at a ratio of 500 mL of polymer solution to 1,250 mL of
isopropanol. The resulting precipitate was then filtered and dried
overnight in a vacuum oven at 60.degree. C., yielding 42 g of
product hydroxyl-terminated polystyrene. The product
hydroxyl-terminated polystyrene exhibited a number average
molecular weight, M.sub.N, of 7.4 kg/mol and a polydispersity, PD,
of 1.07.
Comparative Example C1
Preparation of PS-b-PDMS Diblock Copolymer
[0065] Into a 500 mL 3-neck round bottom reactor under an argon
atmosphere was added cyclohexane (90 mL) and styrene (18.4 g). The
contents of the reactor were then warmed to 40.degree. C. A 0.5 mL
shot of a 1.4 M solution of sec-butyllithium in cyclohexane was
then rapidly added to the reactor via cannula, causing the reactor
contents to turn yellow-orange. The reactor contents were allowed
to stir for 30 minutes. A small portion of the reactor contents was
then withdrawn from the reactor into a small round bottomed flask
containing anhydrous methanol for gel permeation chromatography
analysis of the polystyrene block faulted. Next
2,2,5,5-tetramethyldisilafuran (337 mg) was added to the reactor.
Slowly the orange color began to fade. After 1 hour the contents of
the reactor were a slight yellow. Then a freshly sublimed
hexamethylcyclotrisiloxane (10.1 g) was then transferred to the
reactor via cannula. The reactor contents were allowed to react for
1.5 hours until the reactor contents were colorless. Then dry
tetrahydrofuran (90 mL) was added to the reactor and the reaction
was allowed to proceed for 3.25 hours. Chlorotrimethylsilane (1 mL)
was then added to the reactor to quench the reaction. The product
was isolated by precipitating into 500 mL of methanol and
filtering. After washing with additional methanol, the polymer was
redissolved in 150 mL of methylene chloride, washed three times
with deionized water and then reprecipitated into 500 mL of
methanol. The polymer was then filtered and dried overnight in a
vacuum oven at 70.degree. C., yielding 22.1 g. The
poly(styrene)-b-poly(dimethyl siloxane) block copolymer
("PS-b-PDMS") product exhibited a number average molecular weight,
M.sub.N, of 35.8 kg/mol; a polydispersity, PD, of 1.01 and a 25.0
wt % PDMS content (as determined by .sup.1H NMR).
Example 2
Preparation PMMA-b-PTMSMMA Diblock Copolymer
[0066] Into a 500 mL 3-neck round bottom reactor under an argon
atmosphere was added tetrahydrofuran ("THF")(113 g). The THF was
then cooled in the reactor to -78.degree. C. The contents of the
reactor were then titrated with a 0.36 M solution of
sec-butyllithium in cyclohexane until the contents of the reactor
exhibited a persistent pale yellow color. The contents of the
reactor were then warmed to, and maintained at, 30.degree. C. until
the color of the contents completely disappeared (approximately
10-15 minutes). 1,1-diphenylethylene (0.116 g) diluted in
cyclohexane (2.278 g) was then transferred to the reactor via
cannula. The contents of the reactor were then cooled to
-78.degree. C. Sec-butyllithium (6.15 g) diluted with cyclohexane
to concentration of 0.065 M was then rapidly added to the reactor
via cannula, causing the reactor contents to turn a dark ruby red.
The reactor contents were allowed to stir for 10 minutes. Then
methyl methacrylate (11.53 g) in cyclohexane (5.31 g) was
transferred to the reactor via cannula, causing the color of the
reactor contents to disappear. The reactor contents exhibited a
21.degree. C. temperature rise within 1 minute of the addition of
the methyl methacrylate to the reactor. The contents of the reactor
then cooled back down to -78.degree. C. and the reactor contents
were stirred for an additional 60 minutes. A small portion of the
reactor contents was then withdrawn for gel permeation
chromatography analysis of the polymethyl methacrylate ("PMMA")
block formed. (Trimethylsilyl) methyl methacrylate ("TMSMMA") (4.52
g) diluted in cyclohexane (4.86 g) was then transferred into the
reactor via cannula. Within 2 minutes of the addition of the TMSMMA
to the reactor, the reactor contents warmed to -69.degree. C.
before cooling back down to -78.degree. C. The reactor contents
were stirred for an additional 2.5 hours, after which the reaction
was quenched by the addition of anhydrous methanol to the reactor.
The reactor contents were then precipitated into 1 liter of
methanol. The product solids were collected by vacuum filtration.
After washing with additional methanol, the polymer was redissolved
in 150 mL of methylene chloride, washed twice with deionized water
and then reprecipitated into 1 liter of methanol. The polymer was
then filtered and dried overnight in a vacuum oven at 60.degree.
C., yielding 15.1 g. The product poly(methyl
methacrylate)-b-poly(trimethylsilyl) methyl methacrylate block
copolymer ("PMMA-b-PTMSMMA") exhibited a weight average molecular
weight, M.sub.W, of 31.4 kg/mol; a polydispersity, PD, of 1.21 and
a 30 wt % poly(trimethylsilyl)methyl methacrylate content (as
determined by .sup.1H NMR).
Example 3
Preparation PMMA-b-PTMSMMA Diblock Copolymer
[0067] Into a 500 mL 3-neck round bottom reactor under an argon
atmosphere was added tetrahydrofuran ("THF")(142 g). The THF was
then cooled in the reactor to -78.degree. C. The contents of the
reactor were then titrated with a 0.36 M solution of
sec-butyllithium in cyclohexane until the contents of the reactor
exhibited a persistent pale yellow color. The contents of the
reactor were then warmed to, and maintained at, 30.degree. C. until
the color of the contents completely disappeared (approximately
10-15 minutes). 1,1-diphenylethylene (0.086 g) diluted in
cyclohexane (1.63 g) was then transferred to the reactor via
cannula. The contents of the reactor were then cooled to
-78.degree. C. Sec-butyllithium (4.5 g) diluted with cyclohexane to
concentration of 0.065 M was then rapidly added to the reactor via
cannula, causing the reactor contents to turn a dark ruby red. The
reactor contents were allowed to stir for 21 minutes. Then methyl
methacrylate (11.5 g) in cyclohexane (17.81 g) was transferred to
the reactor via cannula, causing the color of the reactor contents
to disappear. The reactor contents exhibited a 15-20.degree. C.
temperature rise within 1 minute of the addition of the methyl
methacrylate to the reactor. The contents of the reactor then
cooled back down to -78.degree. C. and the reactor contents were
stirred for an additional 30 minutes. A small portion of the
reactor contents was then withdrawn for gel permeation
chromatography analysis of the polymethyl methacrylate ("PMMA")
block formed. (Trimethylsilyl) methyl methacrylate ("TMSMMA") (4.27
g) diluted in cyclohexane (10.26 g) was then transferred into the
reactor via cannula. Within 2 minutes of the addition of the TMSMMA
to the reactor, the reactor contents warmed to -70.degree. C.
before cooling back down to -78.degree. C. The reactor contents
were stirred for an additional 3.75 hours, after which the reaction
was quenched by the addition of anhydrous methanol to the reactor.
The reactor contents were then precipitated into 1 liter of
methanol. The product solids were collected by vacuum filtration.
After washing with additional methanol, the polymer was redissolved
in 150 mL of methylene chloride, washed twice with deionized water
and then reprecipitated into 1 liter of methanol. The polymer was
then filtered and dried overnight in a vacuum oven at 60.degree.
C., yielding 15.1 g. The product poly(methyl
methacrylate)-b-poly(trimethylsilyl) methyl methacrylate block
copolymer ("PMMA-b-PTMSMMA") exhibited a weight average molecular
weight, M.sub.W, of 42.0 kg/mol; a polydispersity, PD, of 1.18 and
a 28 wt % poly(trimethylsilyl)methyl methacrylate content (as
determined by .sup.1H NMR).
Example 4
Substrate Preparation
[0068] Substrates were prepared by cutting pieces
(.about.1''.times.1'') from a silicon wafer having a native oxide
layer. A hydroxyl-terminated polystyrene brush prepared according
to Example 1 was dissolved in toluene to form 1.5 wt % brush
solution. The brush solution was then spin coated onto each
substrate at 3,000 rpm for 1 minute. The deposited brush layer was
then baked by placing the substrate onto a hotplate set at
150.degree. C. for 1 minute. The deposited brush layer was then
annealed by placing the substrate onto another hotplate set at
250.degree. C. for 20 minutes in a nitrogen atmosphere. The
substrate was then cooled to room temperature. The substrate was
then immersed in toluene for 1 minute. The substrate was then spun
dry at 3,000 rpm for 1 minute. The substrate was then placed on a
hotplate set at 110.degree. C. for 1 minute and then stored in
nitrogen until used.
Comparative Example F1
Film Deposition-Self Assembly
[0069] A PS-b-PDMS block copolymer prepared according to
Comparative Example C1 was dissolved in propylene glycol methyl
ether acetate ("PGMEA")(Dowanol.RTM. PMA available from The Dow
Chemical Company) to form a 1.6 wt % solution. The solution was
then hand filtered through a 0.2 .mu.m Whatman syringe filter. The
filtered solution was then spin coated onto the polystyrene brushed
surface of a substrate prepared according to Example 4 at 2,370 rpm
to form a 41.5 nm PS-b-PDMS film. The substrate was then placed on
a hotplate set at 150.degree. C. for 1 minute to bake the film. The
substrate was then placed on another hotplate set at 250.degree. C.
for 1 hour under 50 psig nitrogen to anneal the PS-b-PDMS film.
[0070] A surface wetting layer of PDMS formed on the annealed film
at the atmosphere-film interface. The annealed film was then
treated using two consecutive reactive ion etching (RIE) steps to
reveal the block copolymer morphology of the deposited PS-b-PDMS
film. First, a short CF.sub.4 plasma (10 mT, 50 W) RIE treatment (8
seconds post plasma stabilization) was used to punch through the
surface wetting layer of PDMS. Then, an O.sub.2 plasma RIE
treatment (25 seconds post plasma stabilization) was employed to
remove the polystyrene domains and convert the PDMS domains to
SiO.sub.x.
[0071] The plasma treated film was then examined by Scanning
Electron Microscopy using a Hitachi S-4500 scanning electron
microscope (SEM) with a secondary electron detector. The test
sample was mounted on the SEM stage using double sided carbon tape
and cleaned by blowing nitrogen prior to analysis. An image of the
test sample was collected at 50,000.times. magnification and
working distances between 4 and 8. The film exhibited a pitch of
32.0 nm.
Comparative Example F2
Film Deposition-Self Assembly
[0072] A PMMA-b-PTMSMMA block copolymer prepared according to
Example 2 was dissolved in propylene glycol methyl ether acetate
(PGMEA) to form a 1.2 wt % solution. The solution was then hand
filtered through a 0.2 .mu.m Whatman syringe filter. The filtered
solution was then spin coated onto a polystyrene brushed surface of
a substrate prepared according to Example 4 to form a
PMMA-b-PTMSMMA film. The substrate was then placed on a hotplate
set at 150.degree. C. for 1 minute to bake the film. The substrate
was then placed on another hotplate set at 290.degree. C. under air
for 2 min.
[0073] A surface wetting layer of PTMSMMA formed on the annealed
film at the atmosphere-film interface. The annealed film was then
treated using two consecutive reactive ion etching (RIB) steps to
reveal the block copolymer morphology of the deposited
PMMA-b-PTMSMMA film. First, a short CF.sub.4 plasma (10 mT, 50 W)
RIE treatment (8 seconds post plasma stabilization) was used to
punch through the surface wetting layer of PTMSMMA. Then, an
O.sub.2 plasma RIE treatment (25 seconds post plasma stabilization)
was employed to remove the poly(methyl methacrylate) domains and
converting the PTMSMMA domains to SiO.sub.x.
[0074] The plasma treated product film was then examined by
Scanning Electron Microscopy using a Hitachi S-4500 scanning
electron microscope (SEM) with a secondary electron detector. The
test sample was mounted on the SEM stage using double sided carbon
tape and cleaned by blowing nitrogen prior to analysis. An image of
the test sample was collected at 50,000.times. magnification and
working distances between 4 and 8. The product film exhibited a
pitch of 36.3 nm.
Example 5
Film Deposition-Self Assembly
[0075] A formulation of PMMA-b-PTMSMMA block copolymer prepared
according to Example 2 and 5 wt % of the antioxidant
pentaerythritol
tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)
(Available from BASF under the tradename IRGANOX.RTM. 1010) was
dissolved in propylene glycol methyl ether acetate (PGMEA) to form
a 1.2 wt % solution. The solution was then hand filtered through a
0.2 .mu.m Whatman syringe filter. The filtered solution was then
spin coated onto a polystyrene brushed surface of a substrate
prepared according to Example 4 to form a PMMA-b-PTMSMMA film. The
substrate was then placed on a hotplate set at 150.degree. C. for 1
minute to bake the film. The substrate was then placed on another
hotplate set at 290.degree. C. under air for 2 min.
[0076] A surface wetting layer of PTMSMMA formed on the annealed
film at the atmosphere-film interface. The annealed film was then
treated using two consecutive reactive ion etching (RIE) steps to
reveal the block copolymer morphology of the deposited
PMMA-b-PTMSMMA film. First, a short CF.sub.4 plasma (10 mT, 50 W)
RIE treatment (8 seconds post plasma stabilization) was used to
punch through the surface wetting layer of PTMSMMA. Then, an
O.sub.2 plasma RIE treatment (25 seconds post plasma stabilization)
was employed to remove the poly(methyl methacrylate) domains and
converting the PTMSMMA domains to SiO.sub.x.
[0077] The plasma treated product film was then examined by
Scanning Electron Microscopy using a Hitachi S-4500 scanning
electron microscope (SEM) with a secondary electron detector. The
test sample was mounted on the SEM stage using double sided carbon
tape and cleaned by blowing nitrogen prior to analysis. An image of
the test sample was collected at 50,000.times. magnification and
working distances between 4 and 8. The product film exhibited a
pitch of 35.7 nm with no apparent, detrimental effects from the
elevated antioxidant concentration.
* * * * *