U.S. patent application number 11/167032 was filed with the patent office on 2005-10-27 for radiation curable composition, storing method thereof, forming method of cured film, patterning method, use of pattern, electronic components and optical waveguide.
This patent application is currently assigned to HITACHI CHEMICAL CO., LTD.. Invention is credited to Abe, Koichi, Sakurai, Haruaki.
Application Number | 20050239953 11/167032 |
Document ID | / |
Family ID | 34436893 |
Filed Date | 2005-10-27 |
United States Patent
Application |
20050239953 |
Kind Code |
A1 |
Sakurai, Haruaki ; et
al. |
October 27, 2005 |
Radiation curable composition, storing method thereof, forming
method of cured film, patterning method, use of pattern, electronic
components and optical waveguide
Abstract
The present invention provides a radiation curing composition
comprising (a): a siloxane resin, (b): a photoacid generator or
photobase generator, and (c): a solvent capable of dissolving
component (a) and containing an aprotic solvent.
Inventors: |
Sakurai, Haruaki;
(Hitachi-shi, JP) ; Abe, Koichi; (Hitachi-shi,
JP) |
Correspondence
Address: |
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW
SUITE 700
WASHINGTON
DC
20036
US
|
Assignee: |
HITACHI CHEMICAL CO., LTD.
Tokyo
JP
|
Family ID: |
34436893 |
Appl. No.: |
11/167032 |
Filed: |
June 27, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11167032 |
Jun 27, 2005 |
|
|
|
PCT/JP04/14850 |
Oct 7, 2004 |
|
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Current U.S.
Class: |
524/588 |
Current CPC
Class: |
G03F 7/0045 20130101;
G03F 7/0757 20130101; G03F 7/0048 20130101 |
Class at
Publication: |
524/588 |
International
Class: |
C08L 083/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 2003 |
JP |
P2003-348160 |
Aug 25, 2004 |
JP |
P2004-245105 |
Claims
1-25. (canceled)
26. A radiation curable composition comprising (a) a siloxane
resin, (b) a photoacid generator or photobase generator, and (c) a
solvent capable of dissolving component (a) and containing an
aprotic solvent including an ether-based solvent.
27. A radiation curable composition according to claim 26, wherein
said siloxane resin includes a resin obtainable by hydrolytic
condensation of a compound represented by the following general
formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1-20 organic group, X represents a hydrolyzable
group and n represents an integer of 0-2, with the proviso that
when n is 2, each R' may be the same or different, and when n is
0-2, each X may be the same or different.
28. A radiation curable composition according to claim 26, further
comprises (d): a curing acceleration catalyst.
29. A radiation curable composition according to claim 28, wherein
said curing acceleration catalyst is an onium salt.
30. A radiation curable composition according to claim 28, wherein
said curing acceleration catalyst is a quaternary ammonium
salt.
31. A forming method of a cured film comprising steps of: applying
a radiation curable composition according to claim 26 onto a
substrate and drying the composition to obtain a coating, and
exposing said coating, without heating of said coating after said
exposure step.
32. A forming method of a cured film comprising steps of: applying
a radiation curable composition according to claim 26 onto a
substrate and drying the composition to obtain a coating, exposing
said coating, and heating said coating after said exposure
step.
33. A patterning method comprising steps of: applying a radiation
curable composition according to claim 26 onto a substrate and
drying the composition to obtain a coating, exposing said coating
via a mask and removing the unexposed sections by development,
without heating of the coating after said exposure step.
34. A patterning method comprising steps of applying a radiation
curable composition according to claim 26 onto a substrate and
drying the composition to obtain a coating, exposing said coating
via a mask, heating said coating after said exposure step and
removing the unexposed sections of said coating by development
after said heating step.
35. A patterning method according to claim 33, wherein
tetramethylammonium hydroxide solution is used as the developing
solution in the removal step.
36. An use of a pattern wherein a pattern formed by a patterning
method according to claim 33 is used as a resist mask.
37. An electronic component possessing a cured film formed by a
forming method of a cured film according to claim 31.
38. An optical waveguide possessing a cured film formed by a
forming method of a cured film according to claim 31.
39. An electronic component possessing a pattern formed by a
patterning method according to claim 33.
40. An optical waveguide possessing a pattern formed by a
patterning method according to claim 33.
41. A storage method for a radiation curable composition according
to claim 26, wherein the radiation curable composition is stored at
a temperature of 0.degree. C. or below.
42. A radiation curable composition comprising (a) a siloxane
resin, (b) a photoacid generator or photobase generator, (c) a
solvent capable of dissolving component (a) and containing an
aprotic solvent, and (d) a curing acceleration catalyst.
43. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sub.nSiX.sub.4-n (1) wherein R.sup.1 represents an H or F atom, a
group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20
organic group, X represents a hydrolyzable group and n represents
an integer of 0-2, with the proviso that when n is 2, each R.sup.1
may be the same or different, and when n is 0-2, each X may be the
same or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), (b) a photoacid generator or photobase
generator, and (c) a solvent capable of dissolving component (a)
and containing an aprotic solvent, wherein the compound represented
by the general formula (1) contains a tetraalkoxysilane and a
trialkoxysilane.
44. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-- n (1) wherein R.sup.1 represents an H or F
atom, a group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1
-20 organic group, X represents a hydrolyzable group and n
represents an integer of 0-2, with the proviso that when n is 2,
each R.sup.1 may be the same or different, and when n is 0-2, each
X may be the same or different, an oligomer of compounds
represented by general formula (1) and/or a partial condensate of
compounds represented by general formula (1), (b) a photoacid
generator or photobase generator, and (c) a solvent capable of
dissolving component (a) and containing an aprotic solvent, wherein
the compound represented by the general formula (1) contains a
tetraalkoxysilane and a trialkoxysilane and the tetraalkoxysilane
contains a tetraethoxysilane.
45. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sub.nSiX.sub.4-n (1) wherein R.sup.1 represents an H or F atom, a
group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20
organic group, X represents a hydrolyzable group and n represents
an integer of 0-2, with the proviso that when n is 2, each R.sup.1
may be the same or different, and when n is 0-2, each X may be the
same or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), (b) a photoacid generator or photobase
generator, and (c) a solvent capable of dissolving component (a)
and containing an aprotic solvent, wherein the compound represented
by the general formula (1) contains a tetraalkoxysilane and a
trialkoxysilane and the trialkoxysilane contains a
methyltriethoxysilane.
46. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sub.nSiX.sub.4-n (1) wherein R.sup.1 represents an H or F atom, a
group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1 -20
organic group, X represents a hydrolyzable group and n represents
an integer of 0-2, with the proviso that when n is 2, each R.sup.1
may be the same or different, and when n is 0-2, each X may be the
same or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), (b) a photoacid generator or photobase
generator, and (c) a solvent capable of dissolving component (a)
and containing an aprotic solvent, wherein a total proportion of
the one or more atoms selected from the group consisting of H, F,
B, N, Al, P, Si, Ge, Ti and C atoms bonding to one Si atom with
respect to the Si atom in general formula (1) is from 0.90 to
0.20.
47. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (8):
SiX.sub.4 (8) wherein X represents a hydrolyzable group, an
oligomer of compounds represented by general formula (8) and/or a
partial condensate of compounds represented by general formula (8),
(b) a photoacid generator or photobase generator, and (c) a solvent
capable of dissolving component (a) and containing an aprotic
solvent.
48. A radiation curable composition comprising (a) a siloxane resin
including a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (8):
SiX.sub.4 (8) wherein X represents a hydrolyzable group, an
oligomer of compounds represented by general formula (8) and/or a
partial condensate of compounds represented by general formula (8),
the resin containing a resin obtainable by hydrolytic condensation
of a compound represented by general formula (8), an oligomer of
compounds represented by general formula (8), a partial condensate
of compounds represented by general formula (8), a compound
represented by the following general formula (1):
R.sub.nSiX.sub.4-n (1) wherein R.sup.1 represents an H or F atom, a
group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20
organic group, X represents a hydrolyzable group and n represents
an integer of 1-2, with the proviso that when n is 2, each R.sup.1
may be the same or different, and when n is 1-2, each X may be the
same or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), (b) a photoacid generator or photobase
generator, and (c) a solvent capable of dissolving component (a)
and containing an aprotic solvent.
49. A radiation curable composition comprising (a) a siloxane
resin, (b) a photoacid generator or photobase generator, (c) a
solvent capable of dissolving component (a) and containing an
aprotic solvent, and an organic acid or an inorganic acid, wherein
the aprotic solvent includes an ether acetate-based solvent or an
ether-based solvent.
50. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, without heating of the coating after said exposure
step.
51. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (8): SiX.sub.4 (8) wherein X represents a
hydrolyzable group, an oligomer of compounds represented by general
formula (8) and/or a partial condensate of compounds represented by
general formula (8).
52. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (8): SiX.sub.4 (8) wherein X represents a
hydrolyzable group, an oligomer of compounds represented by general
formula (8) and/or a partial condensate of compounds represented by
general formula (8), and wherein said resin obtainable by
hydrolytic condensation includes a resin obtainable by hydrolytic
condensation of a compound represented by the following general
formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1 -20 organic group, X represents a hydrolyzable
group and n represents an integer of 1-2, with the proviso that
when n is 2, each R.sup.1 may be the same or different, and when n
is 1-2, each X may be the same or different, an oligomer of
compounds represented by general formula (1) and/or a partial
condensate of compounds represented by general formula (1).
53. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1-20 organic group, X represents
a hydrolyzable group and n represents an integer of 0-2, with the
proviso that when n is 2, each R.sup.1 may be the same or
different, and when n is 0-2, each X may be the same or different,
an oligomer of compounds represented by general formula (1) and/or
a partial condensate of compounds represented by general formula
(1), and wherein a total proportion of the one or more atoms
selected from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti
and C atoms bonding to one Si atom with respect to the Si atom of
the resin obtainable by hydrolytic condensation is from 0.90 to
0.20.
54. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1-20 organic group and includes
one or more atoms selected from the group consisting of H, F, N,
Si, Ti and C atoms, X represents a hydrolyzable group and n
represents an integer of 0-2, with the proviso that when n is 2,
each R.sup.1 may be the same or different, and when n is 0-2, each
X may be the same or different, an oligomer of compounds
represented by general formula (1) and/or a partial condensate of
compounds represented by general formula (1), and wherein a total
proportion of the one or more atoms selected from the group
consisting of H, F, B, N, Al, P, Si, Ge, Ti and C atoms bonding to
one Si atom with respect to the Si atom of the resin obtainable by
hydrolytic condensation is from 0.90 to 0.20.
55. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1 -20 organic group and includes
one or more atoms selected from the group consisting of H, F, N, Si
and C atoms, X represents a hydrolyzable group and n represents an
integer of 0-2, with the proviso that when n is 2, each R.sup.1 may
be the same or different, and when n is 0-2, each X may be the same
or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), and wherein a total proportion of the one or
more atoms selected from the group consisting of H, F, B, N, Al, P,
Si, Ge, Ti and C atoms bonding to one Si atom with respect to the
Si atom of the resin obtainable by hydrolytic condensation is from
0.90 to 0.20.
56. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1 -20 organic group, X
represents a hydrolyzable group and n represents an integer of 0-2,
with the proviso that when n is 2, each R.sup.1 may be the same or
different, and when n is 0-2, each X may be the same or different,
an oligomer of compounds represented by general formula (1) and/or
a partial condensate of compounds represented by general formula
(1), and wherein a total proportion of the one or more atoms
selected from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti
and C atoms bonding to one Si atom with respect to the Si atom of
the resin obtainable by hydrolytic condensation is from 0.80 to
0.20.
57. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein the siloxane resin is soluble in an aprotic
solvent containing an ether-based solvent or an ether acetate-based
solvent.
58. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin and a
photoacid generator onto a substrate and drying the composition to
obtain a coating, and exposing said coating to irradiation of light
at a dose of 5-100 mJ/cm.sup.2 without heating of the coating after
said exposure step.
59. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2 without heating of the coating after said exposure
step, wherein the siloxane resin includes a resin obtainable by
hydrolytic condensation of a compound represented by the following
general formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1-20 organic group, X represents a hydrolyzable
group and n represents an integer of 0-2, with the proviso that
when n is 2, each R.sup.1 may be the same or different, and when n
is 0-2, each X may be the same or different, an oligomer of
compounds represented by general formula (1) and/or a partial
condensate of compounds represented by general formula (1).
60. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, and
exposing said coating to irradiation of light at a dose of 5-100
mJ/cm.sup.2, wherein the siloxane resin is soluble in an aprotic
solvent containing an ether-based solvent or an ether acetate-based
solvent, and wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein
R.sup.1 represents an H or F atom, a group containing a B, N, Al,
P, Si, Ge or Ti atom, or a C1 -20 organic group, X represents a
hydrolyzable group and n represents an integer of 0-2, with the
proviso that when n is 2, each R.sup.1 may be the same or
different, and when n is 0-2, each X may be the same or different,
an oligomer of compounds represented by general formula (1) and/or
a partial condensate of compounds represented by general formula
(1).
61. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin and a
photoacid generator onto a substrate and drying the composition to
obtain a coating, and exposing said coating to irradiation of light
at a dose of 5-100 mJ/cm.sup.2, without heating of the coating
after said exposure step, wherein the siloxane resin includes a
resin obtainable by hydrolytic condensation of a compound
represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1 represents an H or F
atom, a group containing a B, N, Al, P, Si, Ge or Ti atom, or a
C1-20 organic group, X represents a hydrolyzable group and n
represents an integer of 0-2, with the proviso that when n is 2,
each R.sup.1 may be the same or different, and when n is 0-2, each
X may be the same or different, an oligomer of compounds
represented by general formula (1) and/or a partial condensate of
compounds represented by general formula (1).
62. A patterning method comprising steps of: applying a radiation
curable composition containing a siloxane resin onto a substrate
and drying the composition to obtain a coating, exposing said
coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2 via
a mask, and removing the unexposed sections of said coating by
development, without heating of the coating after said exposure
step.
63. A patterning method comprising steps of: applying a radiation
curable composition containing a siloxane resin onto a substrate
and drying the composition to obtain a coating, exposing said
coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2 via
a mask, and removing the unexposed sections of said coating by
development, wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (8): SiX.sub.4 (8) wherein X represents a
hydrolyzable group, an oligomer of compounds represented by general
formula (8) and/or a partial condensate of compounds represented by
general formula (8).
64. A patterning method comprising steps of: applying a radiation
curable composition containing a siloxane resin onto a substrate
and drying the composition to obtain a coating, exposing said
coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2 via
a mask, and removing the unexposed sections of said coating by
development, wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (8): SiX.sub.4 (8) wherein X represents a
hydrolyzable group, an oligomer of compounds represented by general
formula (8) and/or a partial condensate of compounds represented by
general formula (8), and wherein said resin obtainable by
hydrolytic condensation includes a resin obtainable by hydrolytic
condensation of a compound represented by the following general
formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1-20 organic group, X represents a hydrolyzable
group and n represents an integer of 1-2, with the proviso that
when n is 2, each R.sup.1 may be the same or different, and when n
is 1-2, each X may be the same or different, an oligomer of
compounds represented by general formula (1) and/or a partial
condensate of compounds represented by general formula (1).
65. A patterning method comprising steps of: applying a radiation
curable composition containing a siloxane resin onto a substrate
and drying the composition to obtain a coating, exposing said
coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2 via
a mask, and removing the unexposed sections of said coating by
development, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1-20 organic group, X represents
a hydrolyzable group and n represents an integer of 0-2, with the
proviso that when n is 2, each R.sup.1 may be the same or
different, and when n is 0-2, each X may be the same or different,
an oligomer of compounds represented by general formula (1) and/or
a partial condensate of compounds represented by general formula
(1), and wherein a total proportion of the one or more atoms
selected from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti
and C atoms bonding to one Si atom with respect to the Si atom of
the resin obtainable by hydrolytic condensation is from 0.90 to
0.20.
66. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1 -20 organic group and includes
one or more atoms selected from the group consisting of H, F, N,
Si, Ti and C atoms, X represents a hydrolyzable group and n
represents an integer of 0-2, with the proviso that when n is 2,
each R.sup.1 may be the same or different, and when n is 0-2, each
X may be the same or different, an oligomer of compounds
represented by general formula (1) and/or a partial condensate of
compounds represented by general formula (1), and wherein a total
proportion of the one or more atoms selected from the group
consisting of H, F, B, N, Al, P, Si, Ge, Ti and C atoms bonding to
one Si atom with respect to the Si atom of the resin obtainable by
hydrolytic condensation is from 0.90 to 0.20.
67. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1-20 organic group and includes
one or more atoms selected from the group consisting of H, F, N, Si
and C atoms, X represents a hydrolyzable group and n represents an
integer of 0-2, with the proviso that when n is 2, each R.sup.1 may
be the same or different, and when n is 0-2, each X may be the same
or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1), and wherein a total proportion of the one or
more atoms selected from the group consisting of H, F, B, N, Al, P,
Si, Ge, Ti and C atoms bonding to one Si atom with respect to the
Si atom of the resin obtainable by hydrolytic condensation is from
0.90 to 0.20.
68. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, wherein said siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1)
wherein R.sup.1 represents an H or F atom, a group containing a B,
N, Al, P, Si, Ge or Ti atom, or a C1-20 organic group, X represents
a hydrolyzable group and n represents an integer of 0-2, with the
proviso that when n is 2, each R' may be the same or different, and
when n is 0-2, each X may be the same or different, an oligomer of
compounds represented by general formula (1) and/or a partial
condensate of compounds represented by general formula (1), and
wherein a total proportion of the one or more atoms selected from
the group consisting of H, F, B, N, Al, P, Si, Ge, Ti and C atoms
bonding to one Si atom with respect to the Si atom of the resin
obtainable by hydrolytic condensation is from 0.80 to 0.20.
69. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, wherein the siloxane resin is soluble in an aprotic
solvent containing an ether-based solvent or an ether acetate-based
solvent.
70. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin and a
photoacid generator onto a substrate and drying the composition to
obtain a coating, exposing said coating to irradiation of light at
a dose of 5-100 mJ/cm.sup.2 via a mask, and removing the unexposed
sections of said coating by development, without heating of the
coating after said exposure step.
71. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, without heating of the coating after said exposure
step, wherein the siloxane resin includes a resin obtainable by
hydrolytic condensation of a compound represented by the following
general formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1-20 organic group, X represents a hydrolyzable
group and n represents an integer of 0-2, with the proviso that
when n is 2, each R' may be the same or different, and when n is
0-2, each X may be the same or different, an oligomer of compounds
represented by general formula (1) and/or a partial condensate of
compounds represented by general formula (1).
72. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin onto a
substrate and drying the composition to obtain a coating, exposing
said coating to irradiation of light at a dose of 5-100 mJ/cm.sup.2
via a mask, and removing the unexposed sections of said coating by
development, wherein the siloxane resin is soluble in an aprotic
solvent containing an ether-based solvent or an ether acetate-based
solvent, and wherein the siloxane resin includes a resin obtainable
by hydrolytic condensation of a compound represented by the
following general formula (1): R.sup.1.sub.nSiX.sub.4-n (1) wherein
R.sup.1 represents an H or F atom, a group containing a B, N, Al,
P, Si, Ge or Ti atom, or a C1-20 organic group, X represents a
hydrolyzable group and n represents an integer of 0-2, with the
proviso that when n is 2, each R.sup.1 may be the same or
different, and when n is 0-2, each X may be the same or different,
an oligomer of compounds represented by general formula (1) and/or
a partial condensate of compounds represented by general formula
(1).
73. A forming method of a cured film comprising steps of: applying
a radiation curable composition containing a siloxane resin and a
photoacid generator onto a substrate and drying the composition to
obtain a coating, exposing said coating to irradiation of light at
a dose of 5-100 mJ/cm.sup.2 via a mask, and removing the unexposed
sections of said coating by development, without heating of the
coating after said exposure step, wherein the siloxane resin
includes a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1) wherein R' represents an H or F atom,
a group containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20
organic group, X represents a hydrolyzable group and n represents
an integer of 0-2, with the proviso that when n is 2, each R' may
be the same or different, and when n is 0-2, each X may be the same
or different, an oligomer of compounds represented by general
formula (1) and/or a partial condensate of compounds represented by
general formula (1).
Description
RELATED APPLICATIONS
[0001] This is a continuation-in-part application of application
Ser. no. PCT/JP2004/14850 filed on Oct. 7, 2004, now pending.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a radiation curable
composition, a storing method thereof, a forming method of a cured
film, a patterning method, an use of a pattern, electronic
components and an optical waveguide.
[0004] 2. Related Background of the Invention
[0005] As insulating films for use in LSIs and PDPs there have
conventionally been used SiO.sub.2 films formed by CVD methods, and
organic SOG (Spin On Glass) or inorganic SOG films formed by
coating methods, because of their excellent heat resistance and
electrical reliability. With insulating films of the prior art,
however, it is impossible to directly form wiring grooves or
contact holes, and usually a photoresist is patterned on the
insulating film, followed by either dry etching with plasma or wet
etching with a chemical solution, after which the film is subjected
to a resist removal step or washing step to form a pattern. On the
other hand, imparting photosensitive properties to an insulating
film material with excellent heat resistance, electrical
reliability and transparency eliminates the need for the resist
material required in the steps mentioned above, thereby allowing
the plasma dry etching, chemical solution wet etching, resist
removal and washing steps to be omitted.
[0006] In recent years there have been proposed radiation curing
polysiloxane materials with excellent heat resistance, electrical
reliability and transparency. For example, in Japanese Patent
Application Laid-Open No. 6-148895 and Japanese Patent Application
Laid-Open No. 10-24696 there are disclosed photosensitive resin
compositions comprising an alkali-soluble siloxane polymer, a
photoacid generator and a solvent, from which the water and
catalyst have been removed. Japanese Patent Application Laid-Open
No. 2000-181069 and Japanese Patent Application Laid-Open No.
2002-72502 disclose photosensitive polysilazane compositions
comprising polysilazane and a photoacid generator. Also, Japanese
Patent Application Laid-Open No. 2001-288364 discloses a radiation
curable composition comprising a hydrolyzable silane compound, a
photoacid generator and an acid diffusion controller.
SUMMARY OF THE INVENTION
[0007] However, when the present inventors conducted a detailed
investigation of patterning using such conventional insulating film
materials imparted with photosensitive properties, it was found
that when employing the photosensitive resin compositions
comprising an alkali-soluble siloxane polymer, a photoacid
generator and a solvent, from which the water and catalyst have
been removed as disclosed in Patent documents 1 and 2, for example,
a large light exposure dose is required in both cases, and
therefore mass production cannot be advantageously accomplished. In
addition, when using the photosensitive polysilazane compositions
comprising polysilazane and a photoacid generator, as disclosed in
Patent documents 3 and 4, the light exposure dose is low but the
steps of dipping in purified water after exposure or steps
requiring humidification treatment are obviously complicated,
making it difficult to obtain high pattern precision. On the other
hand, when using a radiation curable composition comprising a
hydrolyzable silane compound, a photoacid generator and an acid
diffusion controller, as disclosed in Patent document 5, the acid
diffusion controller controls diffusion of the acid generated by
the radiation, thereby allowing the pattern precision of the silane
compound to be increased. Nevertheless, since the acid diffusion
controller inactivates (neutralizes) the acid, the curing property
is impaired in cases with a low amount of photoacid generator or a
low exposure dose, thereby often leading to lower pattern
precision. Conversely, increasing the exposure dose in an attempt
to improve the patterning precision is clearly an unsuitable
strategy for mass production.
[0008] The present invention was accomplished in light of the
circumstances described above, and it provides a radiation curable
composition which yields a cured product with excellent pattern
precision even with a relatively low light exposure dose, a method
for its storage, a forming method of a cured film and a patterning
method, as well as an use of a pattern, electronic components and
an optical waveguide which employ the above.
[0009] When forming patterns by generation of acid with radiation
according to the prior art, the generated acid is inactivated with
an acid diffusion controller to improve the pattern precision. This
requires an increased exposure dose for generation of extra acid to
compensate for the inactivation, and therefore it has been
difficult to achieve both improvement in pattern precision and
reduction in exposure dose.
[0010] Different strategies that have been considered for
controlling diffusion of acid, other than by inactivation of the
acid with an acid diffusion controller, include the strategy of
reducing the exposure dose to reduce the amount of acid generated,
lowering the temperature of the post-exposure baking (PEB) step
after exposure, or eliminating the PEB step. However, the basic
concepts of such strategies have not been elucidated, nor have
radiation curable compositions suited for such strategies existed.
A radiation curable composition suited for such strategies would
allow formation of highly precise patterns without using an acid
diffusion controller. Nevertheless, when patterning is carried out
using conventional radiation curable compositions, reducing the
amount of acid generated prevents curing from proceeding to an
adequate degree. In addition, curing of the exposed sections also
fails to adequately proceed when the temperature of the
post-exposure baking (PEB) step after exposure is lowered or PEB is
not carried out. As a result, it has been difficult to form highly
precise patterns.
[0011] As a result of much diligent research, the present inventors
have completed the present invention after finding that the various
problems of the prior art can be overcome by a radiation curable
composition comprising specific components, a forming method of a
cured film and a patterning method.
[0012] The present invention provides a radiation curable
composition comprising (a): a siloxane resin, (b): a photoacid
generator or photobase generator, and (c): a solvent capable of
dissolving component (a) and containing an aprotic solvent.
[0013] The invention further provides the aforementioned radiation
curable composition wherein the siloxane resin includes a resin
obtainable by hydrolytic condensation of a compound represented by
the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1)
[0014] wherein R.sup.1 represents an H or F atom, a group
containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20 organic
group, X represents a hydrolyzable group and n represents an
integer of 0-2, with the proviso that when n is 2, each R.sup.1 may
be the same or different, and when n is 0-2, each X may be the same
or different.
[0015] The invention further provides the aforementioned radiation
curable composition wherein the aprotic solvent is at least one
solvent selected from the group consisting of ether-based solvents,
ester-based solvents, ether acetate-based solvents and ketone-based
solvents. These aprotic solvents are preferred from the standpoint
of sensitivity and pattern precision during pattern formation, and
mechanical strength of the cured film.
[0016] The invention still further provides the aforementioned
radiation curable composition which further comprises component
(d): a curing acceleration catalyst. Using a curing acceleration
catalyst is preferred because it can heighten the effect of
reducing the amount of photoacid generator or photobase generator,
the effect of reducing the exposure dose or the effect of lowering
the PEB temperature.
[0017] The invention still further provides the aforementioned
radiation curable composition wherein the curing acceleration
catalyst is an onium salt. An onium salt is preferred because it
can improve the electrical properties and mechanical strength of
the obtained cured film, while also increasing the stability of the
composition.
[0018] The invention still further provides the aforementioned
radiation curable composition wherein the curing acceleration
catalyst is a quaternary ammonium salt. Using a quaternary ammonium
salt as the curing acceleration catalyst will more notably produce
the aforementioned effects of improving the electrical properties
and mechanical strength while increasing the stability of the
composition.
[0019] The invention still further provides a forming method of a
cured film comprising steps of applying the aforementioned
radiation curable composition onto a substrate and drying it to
obtain a coating, and exposing the coating, without heating of the
coating after the exposure step. According to this method,
diffusion of the acid by heat and increased production costs are
adequately minimized, while the pattern precision of the cured film
is sufficiently high.
[0020] The invention still further provides a forming method of a
cured film comprising steps of applying the aforementioned
radiation curable composition onto a substrate and drying it to
obtain a coating, exposing the coating, and heating the coating
after the exposure step.
[0021] The invention still further provides a forming method of a
cured film comprising steps of applying a radiation curable
composition containing a siloxane resin onto a substrate and drying
it to obtain a coating, and exposing the coating, without heating
of the coating after the exposure step. According to this method,
diffusion of the acid by heat and increased production costs are
adequately minimized, while the pattern precision of the cured film
is sufficiently high.
[0022] The invention still further provides a forming method of a
cured film comprising steps of applying a radiation curable
composition containing a siloxane resin onto a substrate and drying
it to obtain a coating, exposing the coating, and heating the
coating to 70-110.degree. C. after the exposure step. This method
allows greater inhibition of the diffusion of the acid during
heating.
[0023] The invention still further provides a forming method of a
cured film comprising steps of applying a radiation curable
composition containing a siloxane resin onto a substrate and drying
it to obtain a coating, and exposing the coating to irradiation of
light at a dose of 5-100 mJ/cm.sup.2. A light dose within this
range will tend to facilitate control of exposure and improve the
productivity.
[0024] The invention still further provides a forming method of a
cured film comprising steps of applying a radiation curable
composition containing a siloxane resin onto a substrate and drying
it to obtain a coating, exposing the coating to irradiation of
light at a dose of 5-100 mJ/cm.sup.2, and heating the coating to
70-110.degree. C. after the exposure step.
[0025] The invention still further provides the aforementioned
forming method of a cured film which employs a radiation curable
composition comprising a siloxane resin, wherein the siloxane resin
includes a resin obtainable by hydrolytic condensation of a
compound represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1)
[0026] wherein R.sup.1 represents an H or F atom, a group
containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20 organic
group, X represents a hydrolyzable group and n represents an
integer of 0-2, with the proviso that when n is 2, each R.sup.1 may
be the same or different, and when n is 0-2, each X may be the same
or different.
[0027] The invention still further provides a patterning method
comprising steps of applying the aforementioned radiation curable
composition onto a substrate and drying it to obtain a coating,
exposing the coating via a mask and removing the unexposed sections
of the coating after the exposure step by development, without
heating of the coating after the exposure step. According to this
method, diffusion of the acid by heat and increased production
costs are adequately minimized, while the pattern precision of the
cured film is sufficiently high. The "heat" referred to here means
heat at a stage prior to the removal step, and heating may also be
carried out after the removal step.
[0028] The invention still further provides a patterning method
comprising steps of applying the aforementioned radiation curable
composition onto a substrate and drying it to obtain a coating,
exposing the coating via a mask, heating the coating after the
exposure step and removing the unexposed sections of the coating by
development after the heating step.
[0029] The invention still further provides a patterning method
comprising steps of applying a radiation curable composition
containing a siloxane resin onto a substrate and drying it to
obtain a coating, exposing the coating via a mask, and removing the
unexposed sections of the coating by development, without heating
of the coating after the exposure step. According to this method,
diffusion of the acid by heat and increased production costs are
adequately minimized, while the pattern precision of the cured film
is sufficiently high. The "heat" referred to here means heat at a
stage prior to the removal step, and heating may also be carried
out after the removal step.
[0030] The invention still further provides a patterning method
comprising steps of applying a radiation curable composition
containing a siloxane resin onto a substrate and drying it to
obtain a coating, exposing the coating via a mask, heating the
coating to 70-110.degree. C. after the exposure step, and removing
the unexposed sections of the coating by development after the
heating step. This method allows greater inhibition of the
diffusion of the acid during heating.
[0031] The invention still further provides a patterning method
comprising a step of applying a radiation curable composition
containing a siloxane resin onto a substrate and drying it to
obtain a coating, exposing the coating to irradiation of light at a
dose of 5-100 mJ/cm.sup.2 via a mask, and removing the unexposed
sections of the coating by development. A light dose within this
range will tend to facilitate control of exposure and improve the
productivity.
[0032] The invention still further provides a patterning method
comprising steps of applying a radiation curable composition
containing a siloxane resin onto a substrate and drying it to
obtain a coating, exposing the coating to irradiation of light at a
dose of 5-100 mJ/cm.sup.2 via a mask, heating the coating to
70-110.degree. C. after the exposure step, and removing the
unexposed sections of the coating by development after the heating
step.
[0033] The invention still further provides the aforementioned
patterning method which employs a radiation curable composition
comprising a siloxane resin, wherein the siloxane resin includes a
resin obtainable by hydrolytic condensation of a compound
represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1)
[0034] wherein R.sup.1 represents an H or F atom, a group
containing a B, N, Al, P, Si, Ge or Ti atom, or a C1-20 organic
group, X represents a hydrolyzable group and n represents an
integer of 0-2, with the proviso that when n is 2, each R.sup.1 may
be the same or different, and when n is 0-2, each X may be the same
or different.
[0035] The invention still further provides the aforementioned
patterning method wherein a tetramethylammonium hydroxide solution
is used as the developing solution in the removal step. This method
can adequately inhibit contamination of electronic components by
alkali metals during development.
[0036] The invention still further provides an use of a pattern
wherein a pattern formed by the aforementioned patterning method is
used as a resist mask.
[0037] The invention still further provides an electronic component
possessing a pattern formed by the aforementioned patterning
method.
[0038] The invention still further provides an optical waveguide
possessing a pattern formed by the aforementioned patterning
method.
[0039] The invention still further provides a storage method for
the aforementioned radiation curable composition wherein the
radiation curable composition is stored at a temperature of
0.degree. C. or below. Storing the composition at a temperature of
0.degree. C. or below will result in greater the storage stability
than by storage at a temperature of above 0.degree. C.
[0040] The radiation curable composition having this construction,
the forming method of a cured film and patterning method using the
radiation curable composition, and the storage method for the
radiation curable composition allow formation of cured films with
excellent pattern precision even using a relatively low exposure
dose, thus overcoming the problem of the prior art whereby it has
been impossible to achieve both low exposure dose and high pattern
precision.
[0041] The mechanism responsible for the exhibited effect of the
invention, which has not been achieved in the prior art, is not yet
fully understood. However, the present inventors conjecture that
the reduced exposure dose required for curing according to the
invention is realized because, for instance, there is no need to
use an acid diffusion controller to inhibit diffusion of generated
acid, and an aprotic solvent is used as the solvent to accelerate
curing.
[0042] When a curing acceleration catalyst is further included as
an additive, the effect described above is exhibited more
prominently. This is attributed to the fact that the radiation
curable composition can be more thoroughly cured at a lower
exposure dose.
[0043] The improvement in pattern precision is assumed to result
because the curing reaction of the radiation curable composition
occurs before diffusion of the acid when an aprotic solvent is used
as the curing acceleration solvent. Addition of a curing
acceleration catalyst as an additive also further improves the
pattern precision. This is attributed to the fact that the curing
reaction occurs at a more rapid timing. This mechanism differs from
the mechanism of the prior art, whereby the acid diffusion
controller inactivates (neutralizes) the generated acid to improve
the pattern precision. According to the invention, it is
conjectured that both pattern precision improvement and exposure
dose reduction can be achieved based on the aforementioned
mechanism which is different from that of the prior art.
[0044] The radiation curable composition, method for its storage,
forming method of a cured film and patterning method of the
invention can produce cured films with excellent pattern precision
at relatively low exposure doses. The present invention is
therefore useful for uses of a pattern, electronic components and
optical waveguides.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 is a schematic edge-on view of a preferred embodiment
of an electronic component according to the invention.
[0046] FIG. 2 is an SEM photograph showing a pattern shape
according to an example of the invention.
[0047] FIG. 3 is an SEM photograph showing a pattern shape
according to an example of the invention.
[0048] FIG. 4 is an SEM photograph showing a pattern shape
according to a comparative example of the invention.
[0049] FIG. 5 is an SEM photograph showing a pattern shape
according to a comparative example of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0050] Embodiments of the present invention will now be explained
in detail.
[0051] <Component (a)>
[0052] Component (a) is a siloxane resin, which may be a publicly
known one and preferably has OH groups on the ends or the side
chains of the resin. This will further promote the hydrolytic
condensation reaction for curing of the radiation curable
composition.
[0053] From the standpoint of solubility in the solvent, mechanical
properties and moldability, the siloxane resin preferably has a
weight-average molecular weight (Mw) of 500 to 1 million, more
preferably 500-500,000, even more preferably 500-100,000,
particularly 500-10,000 and most preferably 500-5000. If the
weight-average molecular weight is less than 500, the moldability
of the cured film will tend to be inferior, while if the
weight-average molecular weight is greater than 1 million, the
compatibility with solvents will tend to be reduced. Throughout the
present specification, the weight-average molecular weight is the
value measured by gel permeation chromatography (hereinafter,
"GPC") and calculated using a standard polystyrene calibration
curve.
[0054] The weight-average molecular weight (Mw) may be measured by
GPC under the following conditions, for example.
[0055] Sample: 10 .mu.L radiation curable composition
[0056] Standard polystyrene: Standard polystyrene by Toso Co., Ltd.
(molecular weights: 190,000, 17,900, 9100, 2980, 578, 474, 370,
266)
[0057] Detector: RI monitor Model "L-3000" by Hitachi, Ltd.
[0058] Integrator: GPC integrator Model "D-2200" by Hitachi,
Ltd.
[0059] Pump: Model "L-6000" by Hitachi, Ltd.
[0060] Degas apparatus: Model "Shodex DEGAS" by Showa Denko Co.,
Ltd.
[0061] Column: Models "GL-R440", "GL-R430" and "GL-R420" by Hitachi
Chemical Industries, used serially in that order
[0062] Eluent: Tetrahydrofuran (THF)
[0063] Measuring temperature: 23.degree. C.
[0064] Flow rate: 1.75 mL/min
[0065] Measuring time: 45 min
[0066] As examples of preferred siloxane resins there may be
mentioned resins obtainable by hydrolytic condensation of any
compound represented by the following general formula (1):
R.sup.1.sub.nSiX.sub.4-n (1)
[0067] as the essential component. In this formula, R.sup.1
represents an H or F atom, a group containing a B, N, Al, P, Si, Ge
or Ti atom, or a C1-20 organic group, X represents a hydrolyzable
group and n represents an integer of 0-2, and when n is 2, each
R.sup.1 may be the same or different and when n is 0-2, each X may
be the same or different.
[0068] As examples for the hydrolyzable group X there may be
mentioned alkoxy, halogens, acetoxy, isocyanate and hydroxyl. Among
these, alkoxy is preferred from the standpoint of liquid stability
and coating properties of the composition itself.
[0069] As examples of compounds of general formula (1) wherein the
hydrolyzable group X is an alkoxy group (alkoxysilanes) there may
be mentioned tetraalkoxysilanes, trialkoxysilanes and
dialkoxysilanes.
[0070] As examples of tetraalkoxysilanes there may be mentioned
tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane,
tetra-iso-propoxysilane, tetra-n-butoxysilane,
tetra-sec-butoxysilane, tetra-tert-butoxysilane and
tetraphenoxysilane.
[0071] As examples of trialkoxysilanes there may be mentioned
trimethoxysilane, triethoxysilane, tripropoxysilane,
fluorotrimethoxysilane, fluorotriethoxysilane,
methyltrimethoxysilane, methyltriethoxysilane,
methyltri-n-propoxysilane, methyltri-iso-propoxysi- lane,
methyltri-n-butoxysilane, methyltri-iso-butoxysilane,
methyltri-tert-butoxysilane, methyltriphenoxysilane,
ethyltrimethoxysilane, ethyltriethoxysilane,
ethyltri-n-propoxysilane, ethyltri-iso-propoxysilane,
ethyltri-n-butoxysilane, ethyltri-iso-butoxysilane,
ethyltri-tert-butoxysilane, ethyltriphenoxysilane,
n-propyltrimethoxysilane, n-propyltriethoxysilane,
n-propyltri-n-propoxysilane, n-propyltri-iso-propoxysilane,
n-propyltri-n-butoxysilane, n-propyltri-iso-butoxysilane,
n-propyltri-tert-butoxysilane, n-propyltriphenoxysilane,
iso-propyltrimethoxysilane, iso-propyltriethoxysilane,
iso-propyltri-n-propoxysilane, iso-propyltri-iso-propoxysilane,
iso-propyltri-n-butoxysilane, iso-propyltri-iso-butoxysilane,
iso-propyltri-tert-butoxysilane, iso-propyltriphenoxysilane,
n-butyltrimethoxysilane, n-butyltriethoxysilane,
n-butyltri-n-propoxysila- ne, n-butyltri-iso-propoxysilane,
n-butyltri-n-butoxysilane, n-butyltri-iso-butoxysilane,
n-butyltri-tert-butoxysilane, n-butyltriphenoxysilane,
sec-butyltrimethoxysilane, sec-butyltriethoxysilane,
sec-butyltri-n-propoxysilane, sec-butyltri-iso-propoxysilane,
sec-butyltri-n-butoxysilane, sec-butyltri-iso-butoxysilane,
sec-butyltri-tert-butoxysilane, sec-butyltriphenoxysilane,
t-butyltrimethoxysilane, t-butyltriethoxysilane,
t-butyltri-n-propoxysilane, t-butyltri-iso-propoxysilane,
t-butyltri-n-butoxysilane, t-butyltri-iso-butoxysilane,
t-butyltri-tert-butoxysilane, t-butyltriphenoxysilane,
phenyltrimethoxysilane, phenyltriethoxysilane,
phenyltri-n-propoxysilane, phenyltri-iso-propoxysilane,
phenyltri-n-butoxysilane, phenyltri-iso-butoxysilane,
phenyltri-tert-butoxysilane, phenyltriphenoxysilane,
trifluoromethyltrimethoxysilane, pentafluoroethyltrimethoxysilane,
3,3,3-trifluoropropyltrimethoxysilane and
3,3,3-trifluoropropyltriethoxys- ilane.
[0072] As examples of dialkoxysilanes there may be mentioned
dimethyldimethoxysilane, dimethyldiethoxysilane,
dimethyldi-n-propoxysila- ne, dimethyldi-iso-propoxysilane,
dimethyldi-n-butoxysilane, dimethyldi-sec-butoxysilane,
dimethyldi-tert-butoxysilane, dimethyldiphenoxysilane,
diethyldimethoxysilane, diethyldiethoxysilane,
diethyldi-n-propoxysilane, diethyldi-iso-propoxysilane,
diethyldi-n-butoxysilane, diethyldi-sec-butoxysilane,
diethyldi-tert-butoxysilane, diethyldiphenoxysilane,
di-n-propyldimethoxysilane, di-n-propyldiethoxysilane,
di-n-propyldi-n-propoxysilane, di-n-propyldi-iso-propoxysilane,
di-n-propyldi-n-butoxysilane, di-n-propyldi-sec-butoxysilane,
di-n-propyldi-tert-butoxysilane, di-n-propyldiphenoxysilane,
di-iso-propyldimethoxysilane, di-iso-propyldiethoxysilane,
di-iso-propyldi-n-propoxysilane, di-iso-propyldi-iso-propoxysilane,
di-iso-propyldi-n-butoxysilane, di-iso-propyldi-sec-butoxysilane,
di-iso-propyldi-tert-butoxysilane, di-iso-propyldiphenoxysilane,
di-n-butyldimethoxysilane, di-n-butyldiethoxysilane,
di-n-butyldi-n-propoxysilane, di-n-butyldi-iso-propoxysilane, di-
n-butyldi- n-butoxysilane, di-n-butyldi-sec-butoxysilane,
di-n-butyldi-tert-butoxysilane, di-n-butyldiphenoxysilane,
di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane,
di-sec-butyldi-n-propoxysilane, di-sec-butyldi-iso-propoxysilane,
di-sec-butyldi-n-butoxysilane, di-sec-butyldi-sec-butoxysilane,
di-sec-butyldi-tert-butoxysilane, di-sec-butyldiphenoxysilane,
di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane,
di-tert-butyldi-n-propoxysilane, di-tert-butyldi-iso-propoxysilane,
di-tert-butyldi-n-butoxysilane, di-tert-butyldi-sec-butoxysilane,
di-tert-butyldi-tert-butoxysilane, di-tert-butyldiphenoxysilane,
diphenyldimethoxysilane, diphenyldiethoxysilane,
diphenyldi-n-propoxysila- ne, diphenyldi-iso-propoxysilane,
diphenyldi-n-butoxysilane, diphenyldi-sec-butoxysilane,
diphenyldi-tert-butoxysilane, diphenyldiphenoxysilane,
bis(3,3,3-trifluoropropyl)dimethoxysilane and
methyl(3,3,3-trifluoropropyl)dimethoxysilane.
[0073] As examples of other compounds which are compounds of
general formula (1) wherein R.sup.1 is a C1-20 organic group there
may be mentioned bissilylalkanes and bissilylbenzenes such as
bis(trimethoxysilyl)methane, bis(triethoxysilyl)methane,
bis(tri-n-propoxysilyl)methane, bis(tri-iso-propoxysilyl)methane,
bis(trimethoxysilyl)ethane, bis(triethoxysilyl)ethane,
bis(tri-n-propoxysilyl)ethane, bis(tri-iso-propoxysilyl)ethane,
bis(trimethoxysilyl)propane, bis(triethoxysilyl)propane,
bis(tri-n-propoxysilyl)propane, bis(tri-iso-propoxysilyl)propane,
bis(trimethoxysilyl)benzene, bis(triethoxysilyl)benzene,
bis(tri-n-propoxysilyl)benzene and
bis(tri-iso-propoxysilyl)benzene.
[0074] As examples of compounds of general formula (1) wherein
R.sup.1 is a group containing an Si atom there may be mentioned
hexaalkoxydisilanes such as hexamethoxydisilane,
hexaethoxydisilane, hexa-n-propoxydisilane and
hexa-iso-propoxydisilane, and dialkyltetraalkoxydisilanes such as
1,2-dimethyltetramethoxydisilane, 1,2-dimethyltetraethoxydisilane
and 1,2-dimethyltetrapropoxydisilane.
[0075] As examples of compounds of general formula (1) wherein the
hydrolyzable group X is a halogen atom (halogen group) (halogenated
silanes) there may be mentioned these alkoxysilanes having the
alkoxy groups in the molecules replaced with halogen atoms. As
examples of compounds of general formula (1) wherein the
hydrolyzable group X is an acetoxy group (acetoxysilanes) there may
be mentioned these alkoxysilanes having the alkoxy groups in the
molecules replaced with acetoxy. As examples of compounds of
general formula (1) wherein the hydrolyzable group X is an
isocyanate group (isocyanatosilanes) there may be mentioned these
alkoxysilanes having the alkoxy groups in the molecules replaced
with isocyanate. As examples of compounds of general formula (1)
wherein the hydrolyzable group X is a hydroxyl group
(hydroxysilanes) there may be mentioned these alkoxysilanes having
the alkoxy groups in the molecules replaced with hydroxyl.
[0076] The compounds represented by general formula (1) may be used
alone or in combinations of two or more.
[0077] There may also be used resins obtainable by hydrolytic
condensation of partial condensates such as oligomers of compounds
represented by general formula (1), resins obtainable by hydrolytic
condensation of partial condensates such as oligomers of compounds
represented by general formula (1) with compounds represented by
general formula (1), resins obtainable by hydrolytic condensation
of compounds represented by general formula (1) with other
compounds, and resins obtainable by hydrolytic condensation of
partial condensates such as oligomers of compounds represented by
general formula (1) with compounds represented by general formula
(1) and other compounds.
[0078] As examples of partial condensates such as oligomers of
compounds represented by general formula (1) there may be mentioned
hexaalkoxydisiloxanes such as hexamethoxydisiloxane,
hexaethoxydisiloxane, hexa-n-propoxydisiloxane and
hexa-iso-propoxydisiloxane, as well as partially condensed
trisiloxane, tetrasiloxane and oligosiloxanes.
[0079] As examples of the "other compounds" there may be mentioned
compounds having polymerizable double or triple bonds. As examples
of compounds having polymerizable double bonds there may be
mentioned ethylene, propylene, isobutene, butadiene, isoprene,
vinyl chloride, vinyl acetate, vinyl propionate, vinyl caproate,
vinyl stearate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl
ether, acrylonitrile, styrene, methacrylic acid, methyl
methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl
methacrylate, n-butyl methacrylate, acrylic acid, methyl acrylate,
ethyl acrylate, phenyl acrylate, vinylpyridine, vinylimidazole,
acrylamide, acrylbenzene, diallyl benzene, and partially condensed
forms of these compounds. As compounds with triple bonds there may
be mentioned acetylene, ethynylbenzene and the like.
[0080] The resins obtained in this manner may be used alone or in
combinations of two or more.
[0081] The amount of water used for hydrolytic condensation of the
compound represented by general formula (1) is preferably 0.1-1000
moles and more preferably 0.5-100 moles to 1 mole of the compound
represented by general formula (1). If the amount of water is less
than 0.1 mole, the hydrolytic condensation reaction will tend to
proceed inadequately, while if the amount of water is greater than
1000 moles, gel-like matter will tend to be produced during the
hydrolysis or condensation.
[0082] A catalyst is preferably used for the hydrolytic
condensation of the compound represented by general formula (1). As
examples of suitable catalysts there may be mentioned acid
catalysts, alkali catalysts, metal chelate compounds and the
like.
[0083] As examples of acid catalysts there may be mentioned organic
acids and inorganic acids. As examples of organic acids there may
be mentioned formic acid, maleic acid, fumaric acid, phthalic acid,
malonic acid, succinic acid, tartaric acid, malic acid, lactic
acid, citric acid, acetic acid, propionic acid, butanoic acid,
pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
nonanoic acid, decanoic acid, oxalic acid, adipic acid, sebacic
acid, butyric acid, oleic acid, stearic acid, linolic acid,
linoleic acid, salicylic acid, benzenesulfonic acid, benzoic acid,
p-aminobenzoic acid, p-toluenesulfonic acid, methanesulfonic acid,
trifluoromethanesulfonic acid and trifluoroethanesulfonic acid. As
examples of inorganic acids there may be mentioned hydrochloric
acid, phosphoric acid, nitric acid, boric acid, sulfuric acid and
hydrofluoric acid. These may be used alone or in combinations of
two or more.
[0084] As examples of alkali catalysts there may be mentioned
inorganic alkalis and organic alkalis. As examples of inorganic
alkalis there may be mentioned sodium hydroxide, potassium
hydroxide, rubidium hydroxide and cesium hydroxide. As examples of
organic alkalis there may be mentioned pyridine, monoethanolamine,
diethanolamine, triethanolamine, dimethylmonoethanolamine,
monomethyldiethanolamine, ammonia, tetramethylammoniumhydrooxide,
tetraethylammoniumhydrooxide, tetrapropylammoniumhydrooxide,
methylamine, ethylamine, propylamine, butylamine, pentylamine,
hexylamine, heptylamine, octylamine, nonylamine, decylamine,
undecylamine, dodecylamine, cyclopentylamine, cyclohexylamine,
N,N-dimethylamine, N,N-diethylamine, N,N-dipropylamine,
N,N-dibutylamine, N,N-dipentylamine, N,N-dihexylamine,
N,N-dicyclopentylamine, N,N-dicyclohexylamine, trimethylamine,
triethylamine, tripropylamine, tributylamine, tripentylamine,
trihexylamine, tricyclopentylamine and tricyclohexylamine. These
may be used alone or in combinations of two or more.
[0085] As examples of metal chelate compounds there may be
mentioned metal chelate compounds containing titanium, such as
trimethoxy mono(acetylacetonate)titanium, triethoxy
mono(acetylacetonate)titanium, tri-n-propoxy
mono(acetylacetonate)titanium, tri-iso-propoxy mono
(acetylacetonate) titanium, tri-n-butoxy
mono(acetylacetonate)titanium, tri-sec-butoxy mono
(acetylacetonate) titanium, tri-tert-butoxy
mono(acetylacetonate)titanium, dimethoxy
di(acetylacetonate)titanium, diethoxy di(acetylacetonate)titanium,
di-n-propoxy di(acetylacetonate)titanium, di-iso-propoxy
di(acetylacetonate)titanium, di-n-butoxy
di(acetylacetonate)titanium, di-sec-butoxy
di(acetylacetonate)titanium, di-tert-butoxy
di(acetylacetonate)titanium, monomethoxy
tris(acetylacetonate)titanium, monoethoxy
tris(acetylacetonate)titanium, mono-n-propoxy
tris(acetylacetonate)titani- um, mono-iso-propoxy
tris(acetylacetonate)titanium, mono-n-butoxy
tris(acetylacetonate)titanium, mono-sec-butoxy
tris(acetylacetonate)titan- ium, mono-tert-butoxy
tris(acetylacetonate)titanium, tetrakis(acetylacetonate)titanium,
trimethoxy mono(ethylacetoacetate)tita- nium, triethoxy
mono(ethylacetoacetate)titanium, tri-n-propoxy
mono(ethylacetoacetate)titanium, tri-iso-propoxy
mono(ethylacetoacetate)t- itanium, tri-n-butoxy
mono(ethylacetoacetate)titanium, tri-sec-butoxy
mono(ethylacetoacetate)titanium, tri-tert-butoxy
mono(ethylacetoacetate)t- itanium, dimethoxy
di(ethylacetoacetate)titanium, diethoxy
di(ethylacetoacetate)titanium, di-n-propoxy
di(ethylacetoacetate)titanium- , di-iso-propoxy
di(ethylacetoacetate)titanium, di-n-butoxy
di(ethylacetoacetate)titanium, di-sec-butoxy
di(ethylacetoacetate)titaniu- m, di-tert-butoxy
di(ethylacetoacetate)titanium, monomethoxy
tris(ethylacetoacetate)titanium, monoethoxy
tris(ethylacetoacetate)titani- um, mono-n-propoxy
tris(ethylacetoacetate)titanium, mono-iso-propoxy
tris(ethylacetoacetate)titanium, mono-n-butoxy
tris(ethylacetoacetate)tit- anium, mono-sec-butoxy
tris(ethylacetoacetate)titanium, mono-tert-butoxy
tris(ethylacetoacetate)titanium and
tetrakis(ethylacetoacetate)titanium, as well as the aforementioned
titanium-containing metal chelate compounds wherein the titanium is
replaced with zirconium, aluminum or the like. These may also be
used alone or in combinations of two or more.
[0086] The hydrolysis of the compound represented by general
formula (1) is preferably carried out using such catalysts
mentioned above, but in some cases the stability of the composition
may be impaired or inclusion of the catalyst may have adverse
effects such as corrosion of other materials. In such cases, the
hydrolysis may be followed by, for example, removal of the catalyst
from the composition or reaction with other compounds to inactivate
the function of the catalyst. There are no particular restrictions
on the method of removal or the method of reaction, and removal may
be accomplished by distillation or by ion chromatography. The
hydrolysate obtained from the compound represented by general
formula (1) may also be removed from the composition by
reprecipitation or the like. As an example of a method for
inactivating the function of the catalyst by reaction, if the
catalyst is an alkali catalyst, there may be mentioned a method of
adding an acid catalyst for neutralization by acid-base reaction,
or for adjustment of the pH toward the acidic end.
[0087] The amount of catalyst used is preferably in the range of
0.0001-1 mole to 1 mole of the compound represented by general
formula (1). The reaction may not proceed substantially if the
amount used is less than 0.0001 mole, while gelling may be promoted
during the hydrolytic condensation if the amount is greater than 1
mole.
[0088] The alcohol by-product of hydrolysis is a protic solvent and
is therefore preferably removed using an evaporator or the
like.
[0089] The resin obtained in this manner, from the standpoint of
solubility in the solvent, mechanical properties and moldability,
preferably has a weight-average molecular weight (Mw) of 500 to 1
million, more preferably 500-500,000, even more preferably
500-100,000, particularly 500-10,000 and most preferably 500-5000.
If the weight-average molecular weight is less than 500, the
moldability of the cured film will tend to be inferior, while if
the weight-average molecular weight is greater than 1 million, the
compatibility with solvents will tend to be reduced.
[0090] When adhesion to ground layers and mechanical strength are
required, the total proportion of the one or more atoms selected
from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti and C
atoms with respect to the Si atoms in general formula (1)
(hereunder, this will be referred to as the total number (M) of
specific bonding atoms (R.sup.1 in general formula (1)) is
preferably 1.3-0.2 mole, more preferably 1.0-0.2 mole, even more
preferably 0.90-0.2 mole and most preferably 0.8-0.2 mole. This
will prevent reduction in adhesion to other films (layers) and
mechanical strength of the cured film.
[0091] If the total number (M) of specific bonding atoms is less
than 0.20, the dielectric properties of the cured film as an
insulating film will tend to be inferior, while if it is greater
than 1.3, the finally obtained cured film will tend to have poorer
adhesion to other films (layers) and mechanical strength. Among
these specific bonding atoms, the cured film preferably contains
one or more atoms selected from the group consisting of H, F, N,
Si, Ti and C from the standpoint of moldability, and it preferably
contains one or more selected from the group consisting of H, F, N,
Si and C from the standpoint of dielectric properties and
mechanical strength.
[0092] The total number (M) of specific bonding atoms may be
determined from the charging volume of the siloxane resin, and for
example, it may be calculated using the relationship represented by
the following formula (A):
M=(M1+(M2/2)+(M3/3))/Msi (A)
[0093] In this formula, M1 represents the total number of atoms
bonded with (only) one Si atom among the specific bonding atoms, M2
represents the total number of atoms bonded to two silicon atoms
among the specific bonding atoms, M3 represents the total number of
atoms bonded to three silicon atoms among the specific bonding
atoms, and Msi represents the total number of Si atoms.
[0094] Such siloxane resins may be used alone or in combinations of
two or more. As methods for combining two or more siloxane resins
there may be mentioned, for example, a method of combining two or
more different siloxane resins having different weight-average
molecular weights, and a method of combining two or more different
siloxane resins obtainable by hydrolytic condensation with
different compounds as essential components.
[0095] <Component (b)>
[0096] Component (b) is a photoacid generator or photobase
generator, and it is defined as a compound capable of releasing an
acidic activator or basic activator which can promote photocuring
(hydrolytic polycondensation) of component (a) by exposure to
radiation.
[0097] As examples of photoacid generators there may be mentioned
diarylsulfonium salts, triarylsulfonium salts,
dialkylphenacylsulfonium salts, diaryliodonium salts, aryldiazonium
salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid
esters, nitrobenzyl esters oximesulfonic acid esters, aromatic
N-oximidesulfonates, aromatic sulfamides, haloalkyl
group-containing hydrocarbon-based compounds, haloalkyl
group-containing heterocyclic compounds and
naphthoquinonediazido-4-sulfonic acid esters. These may be used
alone or in combinations of two or more. They may also be used in
combination with other sensitizing agents or the like.
[0098] As examples of photobase generators there may be mentioned
the group of compounds represented by general formulas (2) to (5)
below, nonionic photobase generators such as nifedipines,
cobaltamine complexes, ionic photobase generators such as the
quaternary ammonium salts represented by general formulas (6) and
(7) below, and the like. These may be used alone or in combinations
of two or more. They may also be used in combination with other
sensitizing agents or the like.
(R.sup.2--OCO--NH).sub.m--R.sup.3 (2)
[0099] In this formula, R.sup.2 represents a C1-30 monovalent
organic group which may include an aromatic ring with a methoxy
group or nitro group on a side chain, R.sup.3 represents a C1-20
monovalent to tetravalent organic group, and m represents an
integer of 1-4.
(R.sup.4R.sup.5C.dbd.N--OCO).sub.m--R.sup.3 (3)
[0100] In this formula, R.sup.3 and m have the same definitions as
for general formula (2), and R.sup.4 and R.sup.5 each independently
represent C1-30 monovalent organic groups, which may together form
a cyclic structure.
R--OCO--NR.sup.6R.sup.7 (4)
[0101] In this formula, R.sup.2 has the same definition as for
general formula (2), and R.sup.6 and R.sup.7 each independently
represent C1-30 monovalent organic groups, which may together form
a cyclic structure, and one of which may be a hydrogen atom.
R.sup.8--CO--R.sup.9--NR.sup.6R.sup.7 (5)
[0102] In this formula, R.sup.6 and R.sup.7 have the same
definitions as for general formula (4), R.sup.8 represents a C1-30
monovalent organic group which may include an aromatic ring with an
alkoxy, nitro, amino, alkyl-substituted amino or alkylthio group on
a side chain, and R.sup.9 represents a C1-30 divalent organic
group. 1
[0103] In this formula, R.sup.10 represents a C1-30 monovalent
organic group, R.sup.11 and R.sup.12 each independently represent a
C1-30 organic group or hydrogen atom, X.sup.1 represents a
monovalent group represented by any one of general formulas (6A),
(6B), (6C), (6D), (6E) and (6F) below (hereinafter referred to as
"(6A) to (6F)"), Z.sup.- represents the counter ion of the ammonium
salt, t represents an integer of 1-3, p and q represent integers of
0-2 and t+p+q=3. 2
[0104] In these formulas, R.sup.13, R.sup.14, R.sup.15 and R.sup.16
each independently represent a C1-30 monovalent organic group,
R.sup.17, R.sup.18 and R.sup.19 each independently represent a
C1-30 divalent organic group or a single bond, and R.sup.20 and
R.sup.21 each independently represent a C1-30 trivalent organic
group. 3
[0105] In this formula, R.sup.10, R.sup.11, R.sup.12, Z.sup.-, t, p
and q are the same as in general formula (6) above, and X.sup.2
represents a divalent group represented by any one of general
formulas (7A) to (7D) below. 4
[0106] In these formulas, R.sup.13, R.sup.14, R.sup.15, R.sup.16,
R.sup.17, R.sup.18, R.sup.19, R.sup.20 and R.sup.21 have the same
definitions as in general formulas (6A) to (6F) above.
[0107] The amount of component (b) used is not particularly
restricted, and may be selected from a wide range since it will
depend on the sensitivity and efficiency of the photoacid generator
or photobase generator used, the light source used, the thickness
of the desired cured film, etc. Specifically, the amount of
component (b) used is preferably 0.0001-50 wt %, more preferably
0.001-20 wt % and even more preferably 0.01-10 wt % with respect to
the total amount of component (a) in the radiation curable
composition. If the amount used is less than 0.0001 wt %, the
photocuring property will tend to be reduced or a greater exposure
dose will tend to be necessary for curing, while if it exceeds 50
wt %, the stability and film-forming property of the composition
will tend to be inferior, and the electrical properties and process
adaptability of the cured film will tend to be reduced.
[0108] A photosensitizing agent may be used together with the
aforementioned photoacid generator or photobase generator. Using a
photosensitizing agent will allow efficient absorption of the
radiation energy beam, thereby improving the sensitivity of the
photoacid generator or photobase generator. As examples of
photosensitizing agents there may be mentioned anthracene
derivatives, perylene derivatives, anthraquinone derivatives,
thioxanthone derivatives, coumarin and the like.
[0109] When the radiation curable composition is separated into two
solutions for storage, component (b) and component (a) may be
stored separately for increased storage stability.
[0110] When the radiation curable composition is to be stored
overnight, it is preferably stored at a temperature of, for
example, 0.degree. C. or below. The lower limit for the temperature
is preferably above the congealing point of the solvent in the
radiation curable composition, and more preferably -50.degree.
C.
[0111] <Component (c)>
[0112] Protic solvents, typically alcohols, have a hydrogen atom
bonded to an oxygen atom exhibiting high electronegativity.
Consequently, the protic solvent molecules solvate by forming
hydrogen bonds with nucleophilic reagents and the like.
Specifically, since protic solvents solvate with siloxane resins
obtained by hydrolysis of compounds represented by general formula
(1), the solvent molecules must be removed in order to condense the
siloxane resin, as they tend to inhibit curing at low
temperature.
[0113] Aprotic solvents, on the other hand, are solvents without
hydrogen atoms on highly electronegative elements, and are
therefore less a cause of reaction inhibition than are protic
solvents. Consequently, curing reaction proceeds with generation of
acidic active substances and basic active substances at the exposed
sections, thereby minimizing any reduction in pattern precision due
to diffusion of the acid or base, so that the pattern precision is
improved. This is a different mechanism from that of the prior art
whereby the acid diffusion controller inactivates (neutralizes) the
generated acid to improve the pattern precision. According to the
invention, both pattern precision improvement and exposure dose
reduction are presumably achieved in this manner.
[0114] As examples of aprotic solvents in component (c) there may
be mentioned ketone-based solvents such as acetone, methyl ethyl
ketone, methyl-n-propyl ketone, methyl-iso-propyl ketone,
methyl-n-butyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl
ketone, methyl-n-hexylketone, diethylketone, dipropyl ketone,
di-iso-butyl ketone, trimethyl nonanone, cyclohexanone,
cyclopentanone, methylcyclohexanone, 2,4-pentanedione,
acetonylacetone, .gamma.-butyrolactone and .gamma.-valerolactone;
ether-based solvents such as diethyl ether, methylethyl ether,
methyl-n-propyl ether, di-n-propyl ether, di-iso-propyl ether,
tetrahydrofuran, methyltetrahydrofuran, dioxane, dimethyldioxane,
ethyleneglycol dimethyl ether, ethyleneglycol diethyl ether,
ethyleneglycol di-n-propyl ether, ethyleneglycol dibutyl ether,
diethyleneglycol dimethyl ether, diethyleneglycol diethyl ether,
diethyleneglycol methylethyl ether, diethyleneglycol
methylmono-n-propyl ether, diethyleneglycol methylmono-n-butyl
ether, diethyleneglycol di-n-propyl ether,
diethyleneglycoldi-n-butyl ether, diethyleneglycol
methylmono-n-hexyl ether, triethyleneglycol dimethyl ether,
triethyleneglycol diethyl ether, triethyleneglycol methylethyl
ether, triethyleneglycol methylmono-n-butyl ether,
triethyleneglycol di-n-butyl ether, triethyleneglycol
methylmono-n-hexyl ether, tetraethyleneglycol dimethyl ether,
tetraethyleneglycol diethyl ether, tetradiethyleneglycol
methylethyl ether, tetraethyleneglycol methylmono-n-butyl ether,
tetraethyleneglycol methylmono-n-hexyl ether, tetraethyleneglycol
di-n-butyl ether, propyleneglycol dimethyl ether, propyleneglycol
diethyl ether, propyleneglycol di-n-propyl ether, propyleneglycol
dibutyl ether, dipropyleneglycol dimethyl ether, dipropyleneglycol
diethyl ether, dipropyleneglycol methylethyl ether,
dipropyleneglycol methylmono-n-butyl ether, dipropyleneglycol
di-n-propyl ether, dipropyleneglycol di-n-butyl ether,
dipropyleneglycol methylmono-n-hexyl ether, tripropyleneglycol
dimethyl ether, tripropyleneglycol diethyl ether,
tripropyleneglycol methylethyl ether, tripropyleneglycol
methylmono-n-butyl ether, tripropyleneglycol di-n-butyl ether,
tripropyleneglycol methylmono-n-hexyl ether, tetrapropyleneglycol
dimethyl ether, tetrapropyleneglycol diethyl ether,
tetrapropyleneglycol methylethyl ether, tetrapropyleneglycol
methylmono-n-butyl ether, tetrapropyleneglycol methylmono-n-hexyl
ether and tetrapropyleneglycol di-n-butyl ether; ester-based
solvents such as methyl acetate, ethyl acetate, n-propyl acetate,
i-propyl acetate, n-butyl acetate, i-butyl acetate, sec-butyl
acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl
acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl
acetate, benzyl acetate, cyclohexyl acetate, methylcyclohexyl
acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate,
acetic acid diethyleneglycol monomethyl ether, acetic acid
diethyleneglycol monoethyl ether, acetic acid diethyleneglycol
mono-n-butyl ether, acetic acid dipropyleneglycol monomethyl ether,
acetic acid dipropyleneglycol monoethyl ether, diacetic acid
glycol, acetic acid methoxy triglycol, ethyl propionate, n-butyl
propionate, i-amyl propionate, diethyl oxalate and di-n-butyl
oxalate; ether acetate-based solvents such as ethyleneglycol methyl
ether propionate, ethyleneglycol ethyl ether propionate,
ethyleneglycol methyl ether acetate, ethyleneglycol ethyl ether
acetate, diethyleneglycol methyl ether acetate, diethyleneglycol
ethyl ether acetate, diethyleneglycol-n-butyl ether acetate,
propyleneglycol methyl ether acetate, propyleneglycol ethyl ether
acetate, propyleneglycol propyl ether acetate, dipropyleneglycol
methyl ether acetate and dipropyleneglycol ethyl ether acetate; and
acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone,
N-propylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone,
N-cyclohexylpyrrolidinone, N,N-dimethylformamide,
N,N-dimethylacetamide, N,N-dimethylsulfoxide and the like. From the
standpoint of sensitivity and pattern precision during pattern
formation and mechanical strength of the cured film, ether-based
solvents, ester-based solvents, ether acetate-based solvents and
ketone-based solvents are preferred. Solvents containing no
nitrogen are also preferred. Among these, it is the opinion of the
present inventors that ether acetate-based solvents are the most
preferable, ether-based solvents are the second most preferable,
and ketone-based solvents are the third most preferable. They may
be used alone or in combinations of two or more.
[0115] When the stability of the radiation curable composition is
considered, component (c) is preferably soluble in water or has the
solubility of water, and more preferably it is soluble in water and
has the solubility of water. Thus, a protic solvent is preferably
added when the aprotic solvent is not soluble in water or does not
have the solubility of water. When the aprotic solvent is not
soluble in water or does not have the solubility of water, and
contains no protic solvent, the compatibility with the solvent of
component (a) will be reduced, tending to lower the stability.
However, if sensitivity is desired even at the expense of some
degree of stability, a smaller amount of protic solvent is
preferred.
[0116] As examples of such protic solvents there may be mentioned
alcohol-based solvents such as methanol, ethanol, n-propanol,
i-propanol, n-butanol, i-butanol, sec-butanol, t-butanol,
n-pentanol, i-pentanol, 2-methylbutanol, sec-pentanol, t-pentanol,
3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol,
2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol,
sec-octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol,
trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl
alcohol, phenol, cyclohexanol, methylcyclohexanol, benzyl alcohol,
ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol,
diethylene glycol, dipropylene glycol, triethylene glycol and
tripropylene glycol; ether-based solvents such as ethyleneglycol
methyl ether, ethyleneglycol ethyl ether, ethyleneglycol monophenyl
ether, diethyleneglycol monomethyl ether, diethyleneglycol
monoethyl ether, diethyleneglycol mono-n-butyl ether,
diethyleneglycol mono-n-hexyl ether, ethoxytriglycol,
tetraethyleneglycol mono-n-butyl ether, propyleneglycol monomethyl
ether, dipropyleneglycol monomethyl ether, dipropyleneglycol
monoethyl ether and tripropyleneglycol monomethyl ether; and
ester-based solvents such as methyl lactate, ethyl lactate, n-butyl
lactate and n-amyl lactate. These may be used alone or in
combinations of two or more.
[0117] The proportion of the aprotic solvent used is preferably at
least 50 wt %, more preferably at least 70 wt %, even more
preferably at least 90 wt % and most preferably at least 95 wt % of
the total solvent. If the proportion is too low, the exposed
sections will tend to be inadequately cured with a low exposure
dose. A low proportion may also require heat treatment at high
temperature for adequate curing, while diffusion of the generated
acid or base will be more likely and the pattern precision will
tend to be reduced.
[0118] The method of using component (c) is not particularly
restricted, and for example, it may be a method of using it as a
solvent for preparation of component (a), an addition method or a
solvent-exchange method after preparation of component (a), or a
method of adding the solvent (c) after removing component (a) by
solvent distillation or the like.
[0119] The radiation curable composition of the invention may also
contain water if necessary, but preferably in a range which does
not impair the desired characteristics. The amount of water used is
preferably no greater than 10 wt %, more preferably no greater than
5 wt % and even more preferably no greater than 2 wt % with respect
to the total amount of the radiation curable composition. If the
amount of water used exceeds 10 wt %, the coatability and coating
solution stability will tend to be inferior. Although the exact
reason is unknown, addition of a small amount of water can
sometimes permit reduction of the exposure dose.
[0120] The amount of solvent used (the total of the aprotic solvent
and protic solvent) is preferably an amount which gives a
concentration of 3-60 wt % for component (a) (siloxane resin). If
the amount of solvent is excessive so that the concentration of
component (a) is less than 3 wt %, it will tend to be difficult to
form a cured film with the desired film thickness, while if the
amount of solvent is insufficient so that the concentration of
component (a) is greater than 60 wt %, the film-forming property of
the cured film will be poor and the stability of the composition
itself will tend to be reduced.
[0121] <Component (d)>
[0122] Component (d) according to the invention is a curing
acceleration catalyst, and its addition to the radiation curable
composition is preferred because it can enhance the effect of
reducing the amount of the photoacid generator or photobase
generator required, the effect of reducing the exposure dose
required and the effect of lowering the PEB temperature. The curing
acceleration catalyst differs from an ordinary photoacid generator
or photobase generator for component (b) which generates an active
substance by light. It will therefore usually be distinguished from
an onium salt used as the photoacid generator or photobase
generator. Nevertheless, a material which comprises both the
photoacid generator or photobase generator and the curing
acceleration catalyst may be used.
[0123] The catalyst may be a specific one which does not exhibit a
catalytic effect in solution but exhibits its activity in the
coating after application. Presumably, since the curing reaction
accelerated by the curing acceleration catalyst proceeds
simultaneously with generation of an acidic active substance or
basic active substance at the exposed sections, the reduction in
the pattern precision due to diffusion of the acid or base is
further inhibited, or in other words, the pattern precision is
further improved.
[0124] A process for determining the curing acceleration catalyst
power of the curing acceleration catalyst will now be explained in
four steps.
[0125] 1. A composition comprising component (a) and component (c)
is prepared.
[0126] 2. The composition prepared in 1. above is applied onto a
silicon wafer so that the post-baking film thickness is 1.0.+-.0.1
.mu.m, and then baked for 30 seconds at a prescribed temperature,
and the film thickness of the coating is measured.
[0127] 3. The coating-formed silicon wafer is immersed for 30
seconds into a 2.38 wt % tetramethylammonium hydroxide (TMAH)
aqueous solution at 23.+-.2.degree. C., washed and dried, and then
the coating film loss is observed. The insolubility temperature is
defined as the minimum temperature during baking at which the
change in the coating film thickness before and after immersion in
the TMAH aqueous solution is less than 20%.
[0128] 4. The compound whose curing acceleration catalyst power is
to be confirmed is added to the composition prepared in 1. above at
0.01 wt % to obtain a composition, and the insolubility temperature
is determined in the same manner as 2. and 3. above. If the
insolubility temperature is lowered by addition of the compound
whose curing acceleration catalyst power is to be confirmed, the
compound is judged as having curing acceleration catalyst
power.
[0129] As examples of the curing acceleration catalyst of component
(d) there may be mentioned alkali metals such as sodium hydroxide,
sodium chloride, potassium hydroxide and potassium chloride, and
onium salts. These may be used alone or in combinations of two or
more.
[0130] Onium salts are preferred among these, with quaternary
ammonium salts being more preferred, from the standpoint of
improving the electrical properties and mechanical strength of the
obtained cured film while also increasing the stability of the
composition.
[0131] One example of an onium salt compound which may be mentioned
is a salt formed from (d-1) a nitrogen-containing compound and
(d-2) at least one selected from among anionic group-containing
compounds and halogen atoms. The atom bonded to the nitrogen of the
(d-1) nitrogen-containing compound is preferably at least one
selected from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti
and C atoms. As examples of anionic groups there may be mentioned
hydroxyl, nitrate, sulfate, carbonyl, carboxyl, carbonate and
phenoxy.
[0132] As examples of onium salt compounds there may be mentioned
ammonium salt compounds such as ammonium hydroxide, ammonium
fluoride, ammonium chloride, ammonium bromide, ammonium iodide,
ammonium phosphate, ammonium nitrate, ammonium borate, ammonium
sulfate, ammonium formate, ammonium maleate, ammonium fumarate,
ammonium phthalate, ammonium malonate, ammonium succinate, ammonium
tartrate, ammonium malate, ammonium lactate, ammonium citrate,
ammonium acetate, ammonium propionate, ammonium butanoate, ammonium
pentanoate, ammonium hexanoate, ammonium heptanoate, ammonium
octanoate, ammonium nonanoate, ammonium decanoate, ammonium
oxalate, ammonium adipate, ammonium sebacate, ammonium butyrate,
ammonium oleate, ammonium stearate, ammonium linolate, ammonium
linoleate, ammonium salicylate, ammonium benzenesulfonate, ammonium
benzoate, ammonium p-aminobenzoate, ammonium p-toluenesulfonate,
ammonium methanesulfonate, ammonium trifluoromethanesulfonate and
ammonium trifluoroethanesulfonate.
[0133] There may also be mentioned the aforementioned ammonium salt
compounds wherein the ammonium portion of the ammonium salt
compounds are replaced with methyl ammonium, dimethyl ammonium,
trimethyl ammonium, tetramethyl ammonium, ethyl ammonium, diethyl
ammonium, triethyl ammonium, tetraethyl ammonium, propyl ammonium,
dipropyl ammonium, tripropyl ammonium, tetrapropyl ammonium, butyl
ammonium, dibutyl ammonium, tributyl ammonium, tetrabutyl ammonium,
ethanol ammonium, diethanol ammonium or triethanol ammonium.
[0134] Among these onium salt compounds there are preferred
tetramethylammonium nitrate, tetramethylammonium acetate,
tetramethylammonium propionate, tetramethylammonium maleate and
tetramethylammonium sulfate, from the standpoint of curing
acceleration for the cured film.
[0135] These may be used alone or in combinations of two or
more.
[0136] The amount of component (d) used is preferably 0.0001-5 wt %
and more preferably 0.0001-1 wt %, with respect to the total amount
of component (a) in the radiation curable composition. If the
amount used is less than 0.0001 wt %, a greater exposure dose will
tend to be necessary for curing. If the amount used is greater than
5 wt %, the stability and film-forming property of the composition
will tend to be poor, while the electrical properties and process
adaptability of the cured film will tend to be reduced.
[0137] From the viewpoint of sensitivity and stability, the amount
of the curing acceleration catalyst of component (d) used is
preferably 0.0001-0.1 wt %, more preferably 0.0001-0.05 wt % and
even more preferably 0.0005-0.01 wt % with respect to the total
amount of component (a) in the radiation curable composition.
[0138] These onium salts may also be added after dissolution or
dilution to the prescribed concentration in water or another
solvent, as necessary. There are no particular restrictions on the
timing for the addition, and for example, it may be carried out at
the start of hydrolysis of component (a), during the hydrolysis,
after completion of the reaction, before or after solvent
distillation or at the point of adding the acid generator.
[0139] <Other Components>
[0140] A pigment may also be added to the radiation curable
composition of the invention. Addition of a pigment can produce a
sensitivity-adjusting effect or a stationary wave-inhibiting
effect.
[0141] In addition, surfactants, silane coupling agents,
thickeners, inorganic fillers, thermal decomposing compounds such
as polypropylene glycol, volatile compounds and the like may be
added in ranges which do not interfere with the object or effect of
the invention. Thermal decomposing compounds and volatile compounds
decompose or volatilize by heat (preferably 250-500.degree. C.),
and preferably are capable of forming gaps. The siloxane resin as
component (a) may also exhibit a gap-forming property.
[0142] When the radiation curable composition of the invention is
to be used in an electronic component, it preferably contains no
alkali metal or alkaline earth metal, or maximally at a metal ion
concentration of no greater than 1000 ppm and more preferably no
greater than 1 ppm in the composition. If the concentration of
these metal ions is greater than 1000 ppm, the metal ions will more
readily enter into the electronic component, e.g. semiconductor
element comprising the cured film obtained from the composition,
potentially having an adverse effect on the device performance.
Thus, if necessary, it may be effective to remove the alkali metals
or alkaline earth metals from the composition using an ion-exchange
filter, for example. However, no such restriction exists for use as
an optical waveguide or for other uses, so long as the intended
purpose is not impeded.
[0143] A method of forming a patterned cured film on a substrate
using a radiation curable composition of the invention will now be
explained through an example of a spin coating method, which
generally has excellent film formability and film uniformity.
However, the forming method of a cured film is not limited to a
spin coating method. Also, the substrate may have a flat surface or
it may be irregular, with electrodes or the like formed
therein.
[0144] First, the radiation curable composition is coated onto a
substrate such as a silicon wafer or glass substrate at preferably
500-5000 rpm and more preferably 500-3000 rpm to form a coating. If
the rotation rate is less than 500 rpm, the film uniformity will
tend to be poor, and if the rotation rate is greater than 5000 rpm,
the film-forming property may be impaired.
[0145] The film thickness of the cured film will differ depending
on the intended use, and for example, the film thickness for use as
an interlayer insulating film in an LSI or the like is preferably
0.01-2 .mu.m, while the film thickness is preferably 2-40 .mu.m for
use as a passivation layer. The film thickness for liquid crystal
uses is preferably 0.1-20 .mu.m, the film thickness for photoresist
uses is preferably 0.1-2 .mu.m, and the film thickness for optical
waveguide uses is preferably 1-50 .mu.m. Generally speaking, the
film thickness will be preferably 0.01-10 .mu.m, more preferably
0.01-5 .mu.m, even more preferably 0.01-3 .mu.m, still more
preferably 0.01-2 .mu.m and most preferably 0.1-2 .mu.m. The
concentration of component (a) in the composition may be adjusted
to control the film thickness of the cured film. When a spin
coating method is used, the film thickness may be controlled by
adjusting the rotation rate and number of applications. When the
film thickness is controlled by adjusting the concentration of
component (a), the concentration of component (a) may be increased
for a greater film thickness or the concentration of component (a)
may be decreased for a smaller film thickness. When the film
thickness is controlled using a spin coating method, the rotation
rate may be decreased or the number of applications increased for a
greater film thickness, or alternatively the rotation rate may be
increased or the number applications decreased for a smaller film
thickness.
[0146] The solvent in the coating is then dried with a hot plate at
preferably 50-200.degree. C. and more preferably 70-150.degree. C.,
and the drying temperature must be adjusted so that the coating
will dissolve under the conditions used for subsequent development.
If the drying temperature is below 50.degree. C., drying of the
solvent will tend to be inadequate, and if it is above 200.degree.
C., the film may not dissolve during development and a pattern may
not be formed.
[0147] Next, the film is exposed to radiation via a mask having the
desired pattern. The exposure dose is preferably 5-5000
mJ/cm.sup.2, more preferably 5-1000 mJ/cm.sup.2, even more
preferably 5-500 mJ/cm.sup.2 and most preferably 5-100 mJ/cm.sup.2.
If the exposure dose is less than 5 mJ/cm.sup.2 it may be difficult
to achieve control depending on the light source, and if it is
greater than 5000 mJ/cm.sup.2 the exposure time will be longer,
tending to lower productivity. The exposure dose for an ordinary
siloxane-based radiation curable composition of the prior art is
about 500-5000 mJ/cm.sup.2.
[0148] The radiation employed may be visible light, ultraviolet
light, infrared light, X-rays, .alpha.-rays, .beta.-rays,
.gamma.-rays or the like, although ultraviolet rays are
particularly preferred. As examples of ultraviolet ray generating
sources there may be mentioned ultrahigh voltage mercury lamps,
high voltage mercury lamps, low voltage mercury lamps, metal halide
lamps and excimer lamps.
[0149] The unexposed sections are adequately soluble in the
developing solution, but acidic active substances or basic active
substances are generated at the exposed sections, producing
hydrolytic condensation reaction and lowering the solubility in the
developing solution. This results in formation of a pattern.
[0150] If necessary, the exposure may be followed by a heating step
(post-exposure baking: PEB). The heating may be accomplished by
heating the coating on a hot plate or the like, and preferably the
heating is in a temperature range at which the solubility of the
unexposed sections in the developing solution is not lowered. The
temperature is preferably 50-200.degree. C., more preferably
70-150.degree. C., even more preferably 70-110.degree. C. and most
preferably 70-100.degree. C. A lower temperature is preferred
because a higher temperature will tend to facilitate diffusion of
the generated acid. The heating temperature is usually about
115-120.degree. C. in the PEB step for an ordinary siloxane-based
radiation curable composition of the prior art.
[0151] A developing solution such as an aqueous alkali solution may
be used for development, i.e. for removal of the unexposed sections
of the radiation curable composition. As examples of aqueous alkali
solutions there may be mentioned inorganic alkalis such as sodium
hydroxide, potassium hydroxide, sodium carbonate, sodium silicate,
sodium metasilicate and ammonia; primary amines such as ethylamine
and n-propylamine; secondary amines such as diethylamine and
di-n-propylamine; tertiary amines such as triethylamine and
methyldiethylamine; alcohol amines such as dimethylethanolamine and
triethanolamine; and quaternary ammonium salts such as
tetramethylammonium hydroxide (TMAH) and tetraethylammonium
hydroxide. The aqueous alkali solution may be an aqueous solution
containing an appropriate amount of an added water-soluble organic
solvent or surfactant as appropriate. Since contamination by alkali
metals is undesirable for electronic components, an aqueous
tetramethylammonium hydroxide solution is preferred as the
developing solution.
[0152] The preferred developing time will differ depending on the
film thickness and solvent, but in most cases it is preferably from
5 seconds to 5 minutes, more preferably from 30 seconds to 3
minutes and most preferably from 30 seconds to 1 minute. If the
developing time is shorter than 5 seconds it may be difficult to
control the time on the total surface of the wafer or substrate,
while if it is longer than 5 minutes the productivity may be lower.
The treatment temperature for development will generally be
20-30.degree. C. The developing method may be, for example, a
spray, paddle, immersion or ultrasonic system. The pattern formed
by development may subsequently be rinsed with distilled water or
the like if necessary.
[0153] The patterned cured film of the invention may be also used
directly as a resist mask.
[0154] In cases where the patterned cured film of the invention is
in the form of a residual interlayer insulating film or clad layer,
the coating may be fired at a heating temperature of, for example,
100-500.degree. C. for final curing. The final curing is preferably
carried out in an inert atmosphere of N.sub.2, Ar, He or the like,
in air or under reduced pressure, but there are no particular
restrictions so long as it yields the properties required for the
intended use. If the heating temperature is below 100.degree. C.
the curing may tend to be insufficient, leading to a poor
electrical insulation property, whereas heating at a temperature of
above 500.degree. C. may result in deterioration of the underlying
materials.
[0155] The heating time for the final curing is preferably 2-240
minutes and more preferably 2-120 minutes. A heating time of longer
than 240 minutes may not be suitable for mass production. As
heating apparatuses to be used there may be mentioned furnaces such
as quartz tube furnaces, and heat treatment apparatuses such as hot
plates and rapid thermal annealers (RTA).
[0156] Examples of electronic components employing the cured film
described above include devices comprising insulating films, such
as semiconductor elements, multilayer wiring boards and the like.
Specifically, the cured film may be used as a surface protective
film (passivation film), buffer coat film or interlayer insulating
film for a semiconductor element. It may also be suitably used as
an interlayer insulating film for a multilayer wiring board.
[0157] As examples of semiconductor elements there may be mentioned
discrete semiconductors such as diodes, transistors, compound
semiconductors, thermistors, varistors and thyristors, memory
elements such as DRAM (Dynamic Random Access Memory), SRAM (Static
Random Access Memory), EPROM (Erasable/Programmable Read Only
Memory), Mask ROM (Mask Read Only Memory), EEPROM
(Electrical/Erasable/Programmable Read Only Memory) and flash
memory, logic circuit elements such as microprocessors, DSP and
ASIC, integrated circuit elements such as compound semiconductors
including MMIC (Monolithic Microsave Integrated Circuit), hybrid
integrated circuits (hybrid IC), and photoelectric conversion
elements such as light emitting diodes and charge coupled devices.
As examples of multilayer wiring boards there may be mentioned
high-density wiring boards such as MCM.
[0158] The cured film may also be used for liquid crystal parts,
optical waveguides and photoresists, with no particular limitation
to these.
[0159] FIG. 1 is a schematic edge-on view of an embodiment of a TFT
(Thin-Film Transistor) according to the invention, as an electronic
component for installation in a TFT liquid crystal display. In this
TFT, a conduction layer 3 made of polysilicon is formed on an
undercoat film 2 formed on a glass substrate 1, and a source 4 and
drain 5 are situated sandwiching the conduction layer 3 in the
in-plane direction. A gate electrode 7 is provided on the
conduction layer 3 via a gate oxidation film 6 composed of
SiO.sub.2. The gate oxidation film 6 is formed in such a manner as
to prevent direct contact between the conduction layer 3 and the
gate electrode 7. The undercoat layer 2, conduction layer 3, source
4, drain 5, gate oxidation film 6 and gate electrode 7 are covered
with a first interlayer insulating film 8 to prevent shorting, and
portions of the first interlayer insulating film 8 are removed
during formation of the TFT, with metal wirings 9 extending from
those portions to connect with the source 4 and drain 5,
respectively. The portion of the metal wiring 9 extending to
connect to the drain 5 is electrically connected to a transparent
electrode 11, while the remaining portion is covered with a second
interlayer insulating film 10 to prevent shorting.
[0160] The cured film obtained from the radiation curable
composition of the invention is provided in the TFT primarily as
the second interlayer insulating film 10, but it may also be used
as the first interlayer insulating film 8. The interlayer
insulating films 8,10 may be formed in the following manner, for
example. First, the radiation curable composition of the invention
is applied onto a substrate by a spin coating method and dried to
obtain a coating. Next, the coating is exposed through a mask
having the desired pattern for curing of the desired sections (in
the case of the first interlayer insulating film 8, the sections
other than the sections on which the metal wiring 9 is to be
formed, or in the case of the second interlayer insulating film 10,
the sections other than the sections on which the transparent
electrode 11 is to be formed), and then further subjected to heat
treatment if necessary. The unexposed sections are removed by
developing treatment to obtain interlayer insulating films 8,10.
This may be followed by heat treatment if necessary for final
curing. The interlayer insulating films 8,10 may have the same
composition or different compositions.
EXAMPLES
[0161] Concrete examples of the present invention will now be
explained, with the understanding that the invention is in no way
limited to these examples.
[0162] Each of the examples was carried out in an environment
without the photosensitive wavelength of the photoacid generator or
photobase generator and sensitizing agent used until completion of
the development step for the radiation curable composition, to
avoid exciting the photoacid generator or photobase generator.
Example 1
[0163] To a solution of 317.9 g of tetraethoxysilane and 247.9 g of
methyltriethoxysilane in 1116.7 g of diethyleneglycol dimethyl
ether there was added dropwise 167.5 g of nitric acid, prepared to
0.644 wt %, over a period of 30 minutes while stirring. After
completion of the dropwise addition, reaction was conducted for 3
hours and then a portion of the produced ethanol and the
diethyleneglycol dimethyl ether were distilled off under reduced
pressure in a warm bath to obtain 1077.0 g of a polysiloxane
solution. To 525.1 g of the polysiloxane solution there was added
74.9 g of diethyleneglycol dimethyl ether, and the mixture was
dissolved by 30 minutes of stirring at room temperature (25.degree.
C.) to obtain a polysiloxane solution for a radiation curable
composition. The weight-average molecular weight of the
polysiloxane was 870 as measured by GPC. Next, 0.150 g of a
photoacid generator (PAI-1001, product of Midori Kagaku) was added
to 10.0 g of the radiation curable composition polysiloxane
solution to prepare a radiation curable composition. The amount of
component (a) used was 15 wt % with respect to the total radiation
curable composition, and the amount of component (b) used was 1.5
wt % with respect to the total radiation curable composition.
[0164] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 5-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 200 mJ/cm.sup.2 using an exposing apparatus
(PLA-600F, Canon) through a negative mask bearing a line pattern
with a minimum line width of 10 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, to dissolve the unexposed
sections. The wafer was then washed and spin dried. A furnace body
was used for heating of the spin dried wafer at 350.degree. C. for
30 minutes in a nitrogen atmosphere, to obtain a radiation cured
film on the wafer. Upon observing the pattern shape of the
radiation cured film from the top using an optical microscope and
observing the cross-sectional shape using a SEM, it was found that
the lines had been precisely formed, with a pattern precision of 10
.mu.m. A cross-sectional SEM photograph is shown in FIG. 2.
Example 2
[0165] To a solution of 317.9 g of tetraethoxysilane and 247.9 g of
methyltriethoxysilane in 1116.7 g of diethyleneglycol dimethyl
ether there was added dropwise 167.5 g of nitric acid, prepared to
0.644 wt %, over a period of 30 minutes while stirring. After
completion of the dropwise addition, reaction was conducted for 3
hours and then a portion of the produced ethanol and the
diethyleneglycol dimethyl ether were distilled off under reduced
pressure in a warm bath to obtain 1077.0 g of a polysiloxane
solution. To 525.1 g of the polysiloxane solution there was added
53.0 g of diethyleneglycol dimethyl ether, a tetramethylammonium
nitrate aqueous solution prepared to 2.38 wt % (pH 3.6) and 3.0 g
of water, and the mixture was dissolved by 30 minutes of stirring
at room temperature (25.degree. C.) to obtain a polysiloxane
solution for a radiation curable composition. The weight-average
molecular weight of the polysiloxane was 830 as measured by GPC.
Next, 0.193 g of a photoacid generator (PAI-1001, product of Midori
Kagaku) was added to 10.0 g of the radiation curable composition
polysiloxane solution to prepare a radiation curable composition.
The amount of component (a) used was 15 wt % with respect to the
total radiation curable composition, the amount of component (b)
used was 1.9 wt % with respect to the total radiation curable
composition, and the amount of component (d) used was 0.075 wt %
with respect to the total radiation curable composition.
[0166] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 5-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
70.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 200 mJ/cm.sup.2 using an exposing apparatus
(PLA-600F, Canon) through a negative mask bearing a line pattern
with a minimum line width of 10 .mu.m. The wafer carrying the
exposed coating was immersed for 30 seconds in a developing
solution comprising a 2.38 wt % tetramethylammonium hydroxide
(TMAH) aqueous solution, to dissolve the unexposed sections. The
wafer was then washed and spin dried. A furnace body was used for
heating of the spin dried wafer at 350.degree. C. for 30 minutes in
a nitrogen atmosphere, to obtain a radiation cured film on the
wafer. Upon observing the pattern shape of the radiation cured film
from the top using an optical microscope and observing the
cross-sectional shape using a SEM, it was found that the lines had
been precisely formed, with a pattern precision of 10 .mu.m.
Example 3
[0167] To a solution of 74.77 g of tetraethoxysilane and 128.68 g
of methyltriethoxysilane in 437.86 g of cyclohexanone there was
added dropwise 58.71 g of nitric acid, prepared to 0.644 wt %, over
a period of 10 minutes while stirring. After completion of the
dropwise addition, reaction was conducted for 3 hours and then a
portion of the produced ethanol and the cyclohexanone were
distilled off under reduced pressure in a warm bath to obtain
343.62 g of a polysiloxane solution for a radiation curable
composition. The weight-average molecular weight of the
polysiloxane was 1020 as measured by GPC. Next, 0.042 g of a
photoacid generator (PAI-101, product of Midori Kagaku) was added
to 5.0 g of the radiation curable composition polysiloxane solution
to prepare a radiation curable composition. The amount of component
(a) used was 20 wt % with respect to the total radiation curable
composition, and the amount of component (b) used was 0.8 wt % with
respect to the total radiation curable composition.
[0168] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 6-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 100 mJ/cm.sup.2 using an exposing apparatus
(FPA-3000 iW, Canon) through a negative mask bearing a line pattern
with a minimum line width of 2 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, for paddle development to
dissolve the unexposed sections. The wafer was then washed and spin
dried. A furnace body was used for heating of the spin dried wafer
at 350.degree. C. for 30 minutes in a nitrogen atmosphere, to
obtain a radiation cured film on the wafer. Upon observing the
pattern shape of the radiation cured film from the top using an
optical microscope and observing the cross-sectional shape using a
SEM, it was found that the lines had been precisely formed, with a
pattern precision of 2 .mu.m.
Example 4
[0169] To a solution of 96.13 g of tetraethoxysilane and 165.44 g
of methyltriethoxysilane in 562.99 g of propyleneglycol methyl
ether acetate there were added dropwise 75.47 g of nitric acid,
prepared to 0.644 wt % and 18.9 g of a tetramethylammonium nitrate
aqueous solution prepared to 2.38 wt % (pH 3.6), over a period of 5
minutes while stirring. After completion of the dropwise addition,
reaction was conducted for 3 hours and then a portion of the
produced ethanol and the propyleneglycol methyl ether acetate were
distilled off under reduced pressure in a warm bath to obtain
359.94 g of a polysiloxane solution. Propyleneglycol methyl ether
acetate was then added thereto to obtain 450.02 g of a polysiloxane
solution for a radiation curable composition. The weight-average
molecular weight of the polysiloxane was 1110 as measured by GPC.
Next, 0.080 g of a photoacid generator (PAI-101, product of Midori
Kagaku) was added to 20.0 g of the radiation curable composition
polysiloxane solution to prepare a radiation curable composition.
The amount of component (a) used was 20 wt % with respect to the
total radiation curable composition, the amount of component (b)
used was 0.4 wt % with respect to the total radiation curable
composition, and the amount of component (d) used was 0.1 wt % with
respect to the total radiation curable composition.
[0170] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 6-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 75 mJ/cm.sup.2 using an exposing apparatus
(FPA-3000 iW, Canon) through a negative mask bearing a line pattern
with a minimum line width of 2 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, for paddle development using a
coater/developer (Mark 7, product of Tokyo Electron) to dissolve
the unexposed sections. The wafer was then washed and spin dried. A
furnace body was used for heating of the spin dried wafer at
350.degree. C. for 30 minutes in a nitrogen atmosphere, to obtain a
radiation cured film on the wafer. Upon observing the pattern shape
of the radiation cured film from the top using an optical
microscope and observing the cross-sectional shape using a SEM, it
was found that the lines had been precisely formed, with a pattern
precision of 2 .mu.m. A cross-sectional SEM photograph is shown in
FIG. 3.
Example 5
[0171] To 10.0 g of the radiation curable composition polysiloxane
solution obtained in Example 4 there was added 0.040 g of a
photobase generator (NBC-101, product of Midori Kagaku), to prepare
a radiation curable composition. The amount of component (a) used
was 20 wt % with respect to the total radiation curable
composition, the amount of component (b) used was 0.4 wt % with
respect to the total radiation curable composition, and the amount
of component (d) used was 0.1 wt % with respect to the total
radiation curable composition.
[0172] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 6-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 100 mJ/cm.sup.2 using an exposing apparatus
(FPA-3000 iW, Canon) through a negative mask bearing a line pattern
with a minimum line width of 2 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, for paddle development using a
coater/developer (Mark 7, product of Tokyo Electron) to dissolve
the unexposed sections. The wafer was then washed and spin dried. A
furnace body was used for heating of the spin dried wafer at
350.degree. C. for 30 minutes in a nitrogen atmosphere, to obtain a
radiation cured film on the wafer. Upon observing the pattern shape
of the radiation cured film from the top using an optical
microscope and observing the cross-sectional shape using a SEM, it
was found that the lines had been precisely formed, with a pattern
precision of 2 .mu.m.
Example 6
[0173] To 10.0 g of the radiation curable composition polysiloxane
solution obtained in Example 4 there was added 0.040 g of a
photoacid generator (PAI-101, product of Midori Kagaku) and 0.5 g
of polypropylene glycol (PPG725 by Aldrich) as a thermal
decomposing compound, to prepare a radiation curable composition.
The amount of component (a) used was 20 wt % with respect to the
total radiation curable composition, the amount of component (b)
used was 0.4 wt % with respect to the total radiation curable
composition, and the amount of component (d) used was 0.1 wt % with
respect to the total radiation curable composition.
[0174] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 6-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 100 mJ/cm.sup.2 using an exposing apparatus
(FPA-3000 iW, Canon) through a negative mask bearing a line pattern
with a minimum line width of 2 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, for paddle development using a
coater/developer (Mark 7, product of Tokyo Electron) to dissolve
the unexposed sections. The wafer was then washed and spin dried. A
furnace body was used for heating of the spin dried wafer at
350.degree. C. for 30 minutes in a nitrogen atmosphere, to obtain a
radiation cured film on the wafer. The film thickness of the
radiation cured film was 3.0 .mu.m, and yet no cracking or other
problems were found. Upon observing the pattern shape of the
radiation cured film from the top using an optical microscope and
observing the cross-sectional shape using a SEM, it was found that
the lines had been precisely formed, with a pattern precision of 2
.mu.m.
Comparative Example 1
[0175] To a solution of 132.31 g of tetraethoxysilane and 103.19 g
of methyltriethoxysilane in 464.79 g of propyleneglycol monomethyl
ether there were added dropwise 69.73 g of nitric acid, prepared to
0.644 wt %, over a period of 10 minutes while stirring. After
completion of the dropwise addition, reaction was conducted for 3
hours and then a portion of the produced ethanol and the
propyleneglycol monomethyl ether were distilled off under reduced
pressure in a warm bath to obtain 487.79 g of a polysiloxane
solution. Next, 16.5 g of a tetramethylammonium nitrate aqueous
solution prepared to 2.38 wt % (pH 3.6) was then added dropwise
over a period of 5 minutes while stirring to obtain a polysiloxane
solution for a radiation curable composition. The weight-average
molecular weight of the polysiloxane was 1040 as measured by GPC.
Next, 0.150 g of a photoacid generator (PAI-1001, product of Midori
Kagaku) was added to 10.0 g of the radiation curable composition
polysiloxane solution to prepare a radiation curable composition.
The amount of component (a) used was 15 wt % with respect to the
total radiation curable composition, the amount of component (b)
used was 1.5 wt % with respect to the total radiation curable
composition, and the amount of component (d) used was 0.08 wt %
with respect to the total radiation curable composition.
[0176] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 5-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 200 mJ/cm.sup.2 using an exposing apparatus
(PLA-600F, Canon) through a negative mask bearing a line pattern
with a minimum line width of 10 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, to dissolve the unexposed
sections. When the wafer was washed and spin dried, the entire
coating dissolved leaving no discernible pattern shape.
Comparative Example 2
[0177] The procedure was carried out in the same manner as
Comparative Example 1 up to development, except that the
ultraviolet exposure dose of 200 mJ/cm.sup.2 was changed to 1000
mJ/cm.sup.2. After development, the wafer was washed and spin
dried. A furnace body was used for heating of the spin dried wafer
at 350.degree. C. for 30 minutes in a nitrogen atmosphere, to
obtain a radiation cured film on the wafer. Upon observing the
pattern shape of the radiation cured film from the top using an
optical microscope and observing the cross-sectional shape using a
SEM, it was found that 10 .mu.m-width lines were formed but the
shape was unsatisfactory. A cross-sectional SEM photograph is shown
in FIG. 4.
Comparative Example 3
[0178] To a solution of 44.86 g of tetraethoxysilane, 77.22 g of
methyltriethoxysilane and 0.88 g of a tetramethylammonium nitrate
aqueous solution prepared to 2.38 wt % (pH 3.6) in 122.72 g of
ethanol there was added dropwise 35.22 g of nitric acid, prepared
to 0.644 wt %, over a period of 10 minutes while stirring. After
completion of the dropwise addition, reaction was conducted for 3
hours and then a portion of the produced ethanol was distilled off
under reduced pressure in a warm bath to obtain 205.74 g of a
polysiloxane solution for a radiation curable composition. The
weight-average molecular weight of the polysiloxane was 870 as
measured by GPC. Next, 0.150 g of a photoacid generator (PAI-1001,
product of Midori Kagaku) was added to 10.0 g of the radiation
curable composition polysiloxane solution, but no dissolution
occurred. The amount of component (a) used was 20 wt % with respect
to the total radiation curable composition, the amount of component
(b) used was 1.5 wt % with respect to the total radiation curable
composition, and the amount of component (d) used was 0.01 wt %
with respect to the total radiation curable composition.
Comparative Example 4
[0179] To a solution of 128.87 g of tetraethoxysilane and 100.51 g
of methyltriethoxysilane in 229.97 g of propyleneglycol monomethyl
ether there was added dropwise 67.91 g of nitric acid, prepared to
0.644 wt %, over a period of 10 minutes while stirring. After
completion of the dropwise addition, reaction was conducted for 3
hours to obtain 527.26 g of a polysiloxane solution for a radiation
curable composition. The weight-average molecular weight of the
polysiloxane was 980 as measured by GPC. Next, 0.150 g of a
photoacid generator (PAI-1001, product of Midori Kagaku) was added
to 10.0 g of the radiation curable composition polysiloxane
solution, to obtain a radiation curable composition. The amount of
component (a) used was 15 wt % with respect to the total radiation
curable composition, and the amount of component (b) used was 1.5
wt % with respect to the total radiation curable composition.
[0180] A 2 mL portion of the radiation curable composition was
added dropwise onto the center of a 5-inch silicon wafer and
subjected to spin coating (30 seconds of rotation at 700 rpm) to
form a coating on the wafer, and this was dried for 30 seconds on a
100.degree. C. hot plate. Next, the dried coating was exposed to
ultraviolet rays at 200 mJ/cm.sup.2 using an exposing apparatus
(PLA-600F, Canon) through a negative mask bearing a line pattern
with a minimum line width of 10 .mu.m. The wafer carrying the
exposed coating was heated on a 100.degree. C. hot plate for 30
seconds and then allowed to cool naturally until the wafer reached
room temperature, after which the wafer was immersed for 30 seconds
in a developing solution comprising a 2.38 wt % tetramethylammonium
hydroxide (TMAH) aqueous solution, to dissolve the unexposed
sections. When the wafer was then washed and spin dried, the entire
coating dissolved leaving no discernible pattern shape.
Comparative Example 5
[0181] The procedure was carried out in the same manner as
Comparative Example 4 up to development, except that the
ultraviolet exposure dose of 200 mJ/cm.sup.2 was changed to 1000
mJ/cm.sup.2. After development, the wafer was washed and spin
dried. A furnace body was used for heating of the spin dried wafer
at 350.degree. C. for 30 minutes in a nitrogen atmosphere, to
obtain a radiation cured film on the wafer. Upon observing the
pattern shape of the radiation cured film from the top using an
optical microscope and observing the cross-sectional shape using a
SEM, it was found that 10 .mu.m-width lines were formed but the
shape was unsatisfactory. A cross-sectional SEM photograph is shown
in FIG. 5.
Comparative Example 6
[0182] To a solution of 44.90 g of tetraethoxysilane and 77.20 g of
methyltriethoxysilane in 122.75 g of ethanol there was added
dropwise 35.24 g of nitric acid, prepared to 0.644 wt %, over a
period of 10 minutes while stirring. After completion of the
dropwise addition, reaction was conducted for 3 hours and then a
portion of the produced ethanol was distilled off under reduced
pressure in a warm bath to obtain 210.05 g of a polysiloxane
solution for a radiation curable composition. The weight-average
molecular weight of the polysiloxane was 910 as measured by GPC.
Next, 0.150 g of a photoacid generator (PAI-1001, product of Midori
Kagaku) was added to 10.0 g of the radiation curable composition
polysiloxane solution, but no dissolution occurred. The amount of
component (a) used was 20 wt % with respect to the total radiation
curable composition, and the amount of component (b) used was 1.5
wt % with respect to the total radiation curable composition.
[0183] The results for Examples 1-6 and Comparative Examples 1-6
are shown in Table 1.
1 TABLE 1 Curing Exposure PEB Pattern Aprotic acceleration dose
temperature precision Pattern solvent catalyst (mJ/cm.sup.2)
(.degree. C.) (.mu.m) shape Example 1 present absent 200 100 10
good Example 2 present present 100 None 10 good Example 3 present
absent 100 100 2 good Example 4 present present 75 100 2 good
Example 5 present present 100 100 2 good Example 6 present present
100 100 2 good Comp. Ex. 1 absent present 200 100 no pattern formed
Comp. Ex. 2 absent present 1000 100 10 poor Comp. Ex. 3 absent
present no dissolution of photoacid generator Comp. Ex. 4 absent
absent 200 100 no pattern formed Comp. Ex. 5 absent absent 1000 100
10 poor Comp. Ex. 6 absent absent no dissolution of photoacid
generator
Example 7
[0184] When the radiation curable composition obtained in Example 3
was stored for 30 days in an atmosphere at -20.degree. C., the
storage stability was superior compared to storage of the same
radiation curable composition for 30 days in an atmosphere at
ordinary temperature. The radiation curable composition stored in
an atmosphere at -20.degree. C. was successfully patterned even
after storage for 30 days, but the radiation curable composition
stored for 30 days in an atmosphere at ordinary temperature could
not be patterned even after 7 days. This is attributed to
progressive condensation of the siloxane resin, with concomitant
production of water, in the radiation curable composition stored
for 7 days in an atmosphere at ordinary temperature.
[0185] According to the radiation curable composition, method for
its storage, forming method of a cured film and patterning method
of the invention, it is possible to obtain cured films with
excellent pattern precision even with a relatively low exposure
dose. The invention is therefore useful for uses of a pattern,
electronic components and optical waveguides.
* * * * *