U.S. patent application number 09/526470 was filed with the patent office on 2001-07-05 for developing solution and method of forming polyimide pattern by using the developing solution.
This patent application is currently assigned to Yoshiaki Kawamonzen. Invention is credited to Hayase, Rumiko, Kawamonzen, Yoshiaki, Matake, Shigeru, Mikoshiba, Satoshi.
Application Number | 20010006767 09/526470 |
Document ID | / |
Family ID | 26410295 |
Filed Date | 2001-07-05 |
United States Patent
Application |
20010006767 |
Kind Code |
A1 |
Kawamonzen, Yoshiaki ; et
al. |
July 5, 2001 |
Developing solution and method of forming polyimide pattern by
using the developing solution
Abstract
Disclosed is a developing solution for a photosensitive
polyimide, which consists of an aqueous solution of an amine
compound having a base dissociation index pKb [=-log (Kb)=-log
(Kw/Ka)=14-pKa, where Kb is a base dissociation constant, Ka is
acid dissociation constant of a proton complex, pKa is an acid
dissociation index of a proton complex=-log (Ka), and Kw is an ion
product of water=1.times.10.sup.-14] of 5 to 8 within an aqueous
solution of 25.degree. C.
Inventors: |
Kawamonzen, Yoshiaki;
(Machida-shi, JP) ; Matake, Shigeru;
(Yokohama-shi, JP) ; Hayase, Rumiko;
(Yokohama-shi, JP) ; Mikoshiba, Satoshi;
(Yamato-shi, JP) |
Correspondence
Address: |
Oblon Spivak Mcclelland Maier & Neustadt P C
Fourth Floor
1755 Jefferson Davis Highway
Arlington
VA
22202
US
|
Assignee: |
Yoshiaki Kawamonzen
|
Family ID: |
26410295 |
Appl. No.: |
09/526470 |
Filed: |
March 15, 2000 |
Current U.S.
Class: |
430/330 ;
430/281.1; 430/331 |
Current CPC
Class: |
G03F 7/0233 20130101;
G03F 7/022 20130101; G03F 7/322 20130101 |
Class at
Publication: |
430/330 ;
430/281.1; 430/331 |
International
Class: |
G03F 007/30 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 15, 1999 |
JP |
11-069112 |
Mar 10, 2000 |
JP |
2000-66836 |
Claims
What is claimed is:
1. A developing solution consisting of an aqueous solution of an
amine compound having a base dissociation index pKb of 5 to 8
within an aqueous solution of 25.degree. C.
2. The developing solution according to claim 1, wherein the base
dissociation index pKb of said amine compound within an aqueous
solution of 25.degree. C. is 6 to 7.
3. The developing solution according to claim 1, wherein the
concentration of said amine compound is 0.1 to 20% by weight.
4. The developing solution according to claim 1, wherein the
developing solution is for a photosensitive polyimide.
5. The developing solution according to claim 1, wherein said amine
compound is a tertiary amine compound.
6. The developing solution according to claim 5, wherein the base
dissociation index pKb of said amine compound within an aqueous
solution of 25.degree. C. is 6 to 7.
7. The developing solution according to claim 5, wherein the
concentration of said amine compound is 0.1 to 20% by weight.
8. The developing solution according to claim 5, wherein the
developing solution is for a photosensitive polyimide.
9. The developing solution according to claim 5, wherein said
tertiary amine compound is selected from the group consisting of a
substituted or unsubstituted N-substituted imidazole, a substituted
or unsubstituted N-substituted morpholine, a substituted or
unsubstituted N-substituted pyrroline, a substituted or
unsubstituted N-(2-cyanoethyl)piperazine, a substituted or
unsubstituted N-substituted propargyl piperazine, a substituted or
unsubstituted N-(2-hydroxyethyl)piperazine, a substituted or
unsubstituted 2-(N,N-disubstituted amino)propionitrile, a
substituted or unsubstituted N,N-disubstituted propargylamine, a
substituted or unsubstituted triethanol amine, a substituted or
unsubstituted N-substituted diethanol amine, and a substituted or
unsubstituted N,N-disubstituted tris (hydroxymethyl)amino
methane.
10. The developing solution according to claim 9, wherein the base
dissociation index pKb of said amine compound within an aqueous
solution of 25.degree. C. is 6 to 7.
11. The developing solution according to claim 9, wherein the
concentration of said amine compound is 0.1 to 20% by weight.
12. The developing solution according to claim 9, wherein the
developing solution is for a photosensitive polyimide.
13. The developing solution according to claim 9, wherein said
tertiary amine compound is a substituted or unsubstituted
N-substituted imidazole.
14. The developing solution according to claim 13, wherein the
concentration of said amine compound is 0.1 to 20% by weight.
15. The developing solution according to claim 13, wherein the
developing solution is for a photosensitive polyimide.
16. A method of forming a pattern of a polyimide film, comprising
the steps of: (I) coating a substrate surface with a photosensitive
polyimide solution of a positive type containing a polyimide
precursor and a photosensitive dissolution inhibitor, followed by
heating the coating to form a resin layer; (II) selectively
exposing a desired region of said resin layer to light; (III)
developing the resin layer after the light exposure with a
developing solution consisting of an aqueous solution of an amine
compound having a base dissociation index pKb of 5 to 8 within an
aqueous solution of 25.degree. C.; and (IV) applying a heat
treatment to the resin layer after the development.
17. The method of forming a polyimide film pattern according to
claim 16, wherein said polyimide precursor has a repeating unit
represented by general formula (1): 7where .phi. represents a
tetravalent organic group selected from the group consisting of a
substituted or unsubstituted aliphatic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted alicyclic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted aromatic hydrocarbon group having 1 to 30 carbon
atoms, a substituted or unsubstituted heterocyclic group having 1
to 30 carbon atoms, and a compound radical having said aliphatic
hydrocarbon group, alicyclic hydrocarbon group, aromatic
hydrocarbon group, and heterocyclic group mutually coupled with
each other directly or with a crosslinking group interposed
therebetween; .psi. represents a divalent organic group selected
from the group consisting of a substituted or unsubstituted
aliphatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted alicyclic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted heterocyclic group having 1 to 30 carbon atoms, and a
compound radical having said aliphatic hydrocarbon group, alicyclic
hydrocarbon group, aromatic hydrocarbon group, and heterocyclic
group mutually coupled with each other directly or with a
crosslinking group interposed therebetween; and m is a positive
integer.
18. The method of forming a polyimide film pattern according to
claim 16, wherein said polyimide precursor is synthesized by the
reaction within an organic solvent among 1.0 molar equivalent of
tetracarboxylic dianhydride component containing at least 0.6 molar
equivalent of at least one kind of diphthalic dianhydride selected
from the group consisting of 3,3',4,4'-benzophenone tetracarboxylic
dianhydride, methylene-4,4'-diphthalic dianhydride,
1,1-ethylidene-4,4'-diphthanlic dianhydride,
2,2-propylidene-4,4'-diphthalic dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphthalic dianhydride,
oxy-4,4'-diphthalic dianhydride, thio-4,4'-diphthalic dianhydride,
sulfonyl-4,4'-diphthalic acid dianhydride,
1,3-bis(3,4-dicarboxyphenyl)-1- ,1,3,3-tetramethyl disiloxane
dianhydride, 9-phenyl-9-(trifluoromethyl)xan-
tene-2,3,6,7-tetracarboxylic dianhydride, and
9,9-bis(trifluoromethyl)xant- ene-2,3,6,7-tetracarboxylic
dianhydride; 0.8 to 1.2 molar equivalent of diamine compound
containing at least 0.6 molar equivalent of at least one kind of a
dianiline derivative selected from the group consisting of
oxy-3,3'-dianiline, oxy-3,4'-dianiline, oxy-4,4'-dianiline,
sulfonyl-3,3'-dianiline, sulfonyl-4,4'-dianiline,
methylene-3,3'-dianilin- e, methylene-4,4'-dianiline,
2,2-propylidene-3,3'-dianiline, 2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,- 3'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-5,5'-di(2-toluidine), and
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(2-aminophenol); and
0.02 to 0.2 molar equivalent of at least one kind of a siloxane
compound selected from the group consisting of
1,3-bis(3-aminopropyl)-1,1,3,3-tetr- amethyl disiloxane,
1,5-bis(3-aminopropyl)-1,1,3,3,5,5-hexamethyl trisiloxane,
1,7-bis(3-aminopropyl)-1,1,3,3,5,5,7,7-octamethyl tetrasiloxane,
and 1,11-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11-dode-
camethyl hexasiloxane.
19. The method of forming a polyimide film pattern according to
claim 16, wherein said photosensitive dissolution inhibitor is at
least one naphthoquinone diazide compound selected from the
compounds represented by general formulas (2) to (5): 8where Q,
which may be the same or different, represents a hydrogen atom, a
1,2-naphtoquinone-2-diazide-4-su- lfonyl group or a
1,2-naphtoquinone-2-diazide-5-sulfonyl group, at least one
substituent Q being a 1,2-naphtoquinone-2-diazide-4-sulfonyl group
or a 1,2-naphtoquinone-2-diazide-5-sulfonyl group; R, which may be
the same or different, represents a hydrogen atom, a substituted or
unsubstituted aliphatic hydrocarbon group, a substituted or
unsubstituted alicyclic hydrocarbon group, a substituted or
unsubstituted aromatic hydrocarbon group, or a substituted or
unsubstituted heterocyclic group; T, which may be the same or
different, represents a substituted or unsubstituted aliphatic
hydrocarbon group, a substituted or unsubstituted alicyclic
hydrocarbon group, a substituted or unsubstituted aromatic
hydrocarbon group, or a substituted or unsubstituted heterocyclic
group; X, which may be the same or different, represents an oxy
group, a thio group, a sulfonyl group, a carbonyl group, a
methylene group, an ethylidene group, a 2,2-propylidene group, a
1,1,1,3,3,3-hexafluoro-2,2-propylidene group, a
1-phenyl-1,1-ethylidene group, a 1,1-cyclohexylidene group or a
9,9-fluorenylidene group; Z, which may be the same or different,
represents an oxy group or an imino group, j is an integer of 0 to
3, k, which may be the same or different, is an integer of 1 to 3,
and n, which may be the same or different, is an integer of 0 to
4.
20. The method of forming a polyimide film pattern according to
claim 16, wherein said developing solution is an aqueous solution
of an amine compound having a base dissociation index pKb of 5 to 8
within an aqueous solution of 25.degree. C. and said amine compound
is selected from the group consisting of a substituted or
unsubstituted N-substituted imidazole, a substituted or
unsubstituted N-substituted morpholine, a substituted or
unsubstituted N-substituted pyrroline, a substituted or
unsubstituted N-(2-cyanoethyl)piperazine, a substituted or
unsubstituted N-substituted propargyl piperazine a substituted or
unsubstituted N-(2-hydroxyethyl)piperazine, a substituted or
unsubstituted 2-(N,N-disubstituted amino)propionitirile, a
substituted or unsubstituted N,N-disubstituted amino
propargylamine, a substituted or unsubstituted triethanol amine, a
substituted or unsubstituted N-substituted diethanol amine, and a
substituted or unsubstituted N,N-disubstituted
tris(hydroxymethyl)amino methane.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Application No. 11-069112,
filed Mar. 15, 1999, the entire contents of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a developing solution for a
photosensitive resin, which permits markedly improving the residual
film characteristics and the resolution characteristics in the
formation of a photosensitive polyimide pattern used as, for
example, an insulating member, a protective film member, a liquid
crystal element member or an optical element member. The present
invention also relates to a pattern forming method that permits
obtaining a polyimide film pattern excellent in resolution, heat
resistance and adhesivity and used for forming an insulating film,
a protective film, an .alpha.-ray shielding film or an optical
waveguide of various electronic parts. Further, the present
invention relates to an electronic part prepared by employing the
particular pattern forming method.
[0003] In the ordinary semiconductor device comprising a
semiconductor substrate, the surface of the semiconductor substrate
bearing semiconductor elements is generally covered with a
protective film called a passivation film for the purpose of
improving the reliability of the semiconductor device by protecting
the semiconductor elements from any influence by the outer
environment. As a material for this passivation film, polyimide
resin is extensively employed in view of its excellent properties
such as electric properties, e.g. insulating characteristics,
radiation resistance, environmental stability and heat resistance.
Furthermore, this polyimide is widely employed in a semiconductor
device as an a-ray shielding film, or as an interlayer insulating
film for a multilayered wiring structure or for a multilayered
element structure (a multichip module).
[0004] This polyimide can be easily formed into a film from
polyamic acid which is a precursor for the polyimide. Namely, a
varnish of polyamic acid is coated on the surface of a
predetermined substrate and then the coated layer is heated to form
a film of polyamic acid, which is then heat-treated at a high
temperature thereby to cause a cyclodehydration reaction of the
polyamic acid to take place, thus curing the polyamic acid film and
forming a polyimide film. It is possible, with the employment of
this method, to easily form a film of polyimide in spite of the
fact that polyimide can be hardly worked since it is not or hardly
soluble to most of organic solvents and is high in softening point.
Therefore, the aforementioned method has been widely adopted in the
formation of polyimide film.
[0005] Meanwhile, in the manufacture of a semiconductor device,
various workings, for example, for forming a through-hole in a
multilayered wiring structure or for forming a pad for effecting an
electric connection with an external lead are required. In order to
carry out these workings, a polyimide film formed as a protective
film (passivation film) or an interlayer insulating film as
explained above is required to be patterned thereby to form holes
or grooves of predetermined patterns. Generally, the patterning of
polyimide film is performed by making use of PEP (photo-engraving
process) using a photoresist. Namely, after a polyimide film is
formed on the surface of a semiconductor substrate bearing a
semiconductor element thereon by the aforementioned method, a
photoresist film is formed on the surface of the polyimide film and
then subjected to a light exposure process followed by a
development process thereby forming a resist pattern. Then, the
underlying polyimide film is selectively etched by using this
resist pattern as an etching mask thereby to form a polyimide
protective film or interlayer insulating film having a prescribed
pattern.
[0006] However, the aforementioned method of forming a polyimide
pattern requires two independent steps, i.e. a step of forming a
polyimide film and a step of the PEP, making the method troublesome
to carry out.
[0007] With a view to solve the aforementioned drawback in carrying
out the method, a method of patterning a polyimide film without
employing the PEP has been demanded. In response to such a demand,
a resin composition comprising a polyimide precursor has been
proposed.
[0008] For example, each of Japanese Patent Disclosure (Kokai) No.
52-13315 and Japanese Patent Disclosure No. 62-135824 discloses a
composition prepared by adding an o-quinone diazide compound as a
photosensitizer to a polyimide precursor as a photosensitive resin
composition having a photosensitivity of positive type.
[0009] Each of these photosensitive resin compositions is prepared
by adding a photosensitizer (inhibitor of a photosensitive
dissolution) to a polyimide precursor, i.e., polyamic acid. For
forming a polyimide film pattern by using such a photosensitive
resin composition, a substrate surface is coated with a solution of
the photosensitive resin composition, followed by drying the
coating to form a resin layer and subsequently forming a pattern by
light exposure and developing treatments. Further, a heat treatment
is applied to the resin layer so as to cure, or imidize, the
polyimide precursor by a dehydration-cylization reaction.
[0010] These photosensitive resin compositions can be developed
with an alkaline developing solution. It was customary to use as
the alkaline developing solution for the photosensitive polyimide
an aqueous solution of an inorganic alkaline material such as
sodium hydroxide, potassium hydroxide, sodium carbonate and
potassium carbonate and an organic alkaline material such as
tetramethyl ammonium hydroxide, choline, triethyl amine, ethanol
amine, or diethyl ethanol amine, said aqueous solution being widely
used as an alkaline developing solution for a photoresist
material.
[0011] These inorganic and organic alkaline materials are compounds
having a very strong basicity. Specifically, these inorganic and
organic alkaline materials have a base dissociation index pKb not
larger than 4.5 (i.e., acid dissociation index pKa of the proton
complex not smaller than 9.5). Since an aqueous solution of these
inorganic and organic alkaline materials dissolves the
photosensitive polyimide very rapidly, the aqueous solution is used
as a dilute solution having a concentration not higher than 0.05
mol/L (liter).
[0012] However, use of the conventional developing solution for the
photosensitive polyimide gives rise to serious problems that the
resolution characteristics and the residual film characteristics
are very poor.
BRIEF SUMMARY OF THE INVENTION
[0013] An object of the present invention, which has been achieved
in view of the above-noted problems inherent in the prior art, is
to provide a developing solution capable of markedly improving the
resolution characteristics and the residual film characteristics of
the photosensitive polyimide.
[0014] Another object of the present invention is to provide a
pattern forming method that permits forming a polyimide film
pattern excellent in resolution characteristics and residual film
characteristics without using separately a photoresist.
[0015] According to a first aspect of the present invention, there
is provided a developing solution consisting of an aqueous solution
of an amine compound having a base dissociation index pKb of 5 to 8
within the aqueous solution at 25.degree. C.
[0016] According to a second aspect of the present invention, there
is provided a developing solution consisting of an aqueous solution
of a substituted or unsubstituted N-substituted imidazole having a
base dissociation index pKb of 5 to 8 within the aqueous solution
at 25.degree. C.
[0017] Further, according to a third aspect of the present
invention, there is provided a method of forming a polyimide film
pattern, comprising the steps of:
[0018] (I) coating a substrate surface with a photosensitive
polyimide solution of a positive type containing a polyimide
precursor and a photosensitive dissolution inhibitor, followed by
heating the coating to form a resin layer;
[0019] (II) exposing a desired region of said resin layer to
light;
[0020] (III) developing the resin layer after the light exposure
with a developing solution consisting of an aqueous solution of an
amine compound having a base dissociation index pKb of 5 to 8
within the aqueous solution at 25.degree. C.; and
[0021] (V) applying a heat treatment to the resin layer after the
development.
[0022] The developing solution of the present invention is suitably
used for development of a photosensitive polyimide pattern.
[0023] It is desirable for the polyimide precursor used in the
method of forming a polyimide film pattern to be a polyamic acid
having a repeating unit represented by a general formula (1) given
below: 1
[0024] where .phi. represents a tetravalent organic group selected
from the group consisting of a substituted or unsubstituted
aliphatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted alicyclic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted heterocyclic group having 1 to 30 carbon atoms, and a
compound group having an aliphatic hydrocarbon group, an alicyclic
hydrocarbon group, an aromatic hydrocarbon group or a heterocyclic
group coupled with each other directly or with a crosslinking group
interposed therebetween, .psi. represents a divalent organic group
selected from the group consisting of a substituted or
unsubstituted aliphatic hydrocarbon group having 1 to 30 carbon
atoms, a substituted or unsubstituted alicyclic hydrocarbon group
having 1 to 30 carbon atoms, a substituted or unsubstituted
aromatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted heterocyclic group having 1 to 30
carbon atoms, and a compound group having an aliphatic hydrocarbon
group, an alicyclic hydrocarbon group, an aromatic hydrocarbon
group or a heterocyclic group coupled with each other directly or
with a crosslinking group interposed therebetween, and m is a
positive integer.
[0025] It is particularly desirable to use a polyamic acid as the
polyimide precursor. The polyamic acid suitable for use in the
present invention can be synthesized by the reaction within an
organic solvent among 1.0 molar equivalent of tetracarboxylic
dianhydride component containing at least 0.6 molar equivalent of
at least one kind of diphthalic dianhydride selected from the group
consisting of 3,3',4,4'-benzophenone tetracarboxylic dianhydride,
methylene-4,4'-diphthalic dianhydride,
1,1-ethylidene-4,4'-diphthanlic dianhydride,
2,2-propylidene-4,4'-diphthalic dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphthalic dianhydride,
oxy-4,4'-diphthalic dianhydride, thio-4,4'-diphthalic dianhydride,
sulfonyl-4,4'-diphthalic acid dianhydride,
1,3-bis(3,4-dicarboxyphenyl)-1- ,1,3,3-tetramethyl disiloxane
dianhydride, 9-phenyl-9-(trifluoromethyl)xan-
tene-2,3,6,7-tetracarboxylic dianhydride, and
9,9-bis(trifluoromethyl)xant- ene-2,3,6,7-tetracarboxylic
dianhydride; 0.8 to 1.2 molar equivalent of diamine compound
containing at least 0.6 molar equivalent of at least one kind of a
dianiline derivative selected from the group consisting of
oxy-3,3'-dianiline, oxy-3,4'-dianiline, oxy-4,4'-dianiline,
sulfonyl-3,3'-dianiline, sulfonyl-4,4'-dianiline,
methylene-3,3'-dianilin- e, methylene-4,4'-dianiline,
2,2-propylidene-3,3'-dianiline, 2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,- 3'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-5,5'-di(2-toluidine), and
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(2-aminophenol); and
0.02 to 0.2 molar equivalent of at least one kind of a siloxane
compound selected from the group consisting of
1,3-bis(3-aminopropyl)-1,1,3,3-tetr- amethyl disiloxane,
1,5-bis(3-aminopropyl)-1,1,3,3,5,5-hexamethyl trisiloxane,
1,7-bis(3-aminopropyl)-1,1,3,3,5,5,7,7-octamethyl tetrasiloxane,
and 1,11-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11-dode-
camethyl hexasiloxane.
[0026] It is desirable for the photosensitive dissolution inhibitor
used in the method of forming a polyimide film pattern to be a
naphthoquinone diazide sulfonic ester compound or a naphthoquinone
diazide sulfonic acid amide compound obtained by the reaction
between a phenol compound or an aniline compound and naphthoquinone
diazide sulfonyl chloride compound.
[0027] It is particularly desirable to use at least one kind of the
naphthoquinone diazide compound selected from the compounds
represented by general formulas (2) to (5) given below: 2
[0028] where Q, which may be the same or different, represents a
hydrogen atom, a 1,2-naphtoquinone-2-diazide-4-sulfonyl group or
1,2-naphtoquinone-2-diazide-5-sulfonyl group, at least one
substituent Q being a 1,2-naphtoquinone-2-diazide-4-sulfonyl group
or a 1,2-naphtoquinone-2-diazide-5-sulfonyl group; R, which may be
the same or different, represents a hydrogen atom, a substituted or
unsubstituted aliphatic hydrocarbon group, a substituted or
unsubstituted alicyclic hydrocarbon group, a substituted or
unsubstituted aromatic hydrocarbon group, or a substituted or
unsubstituted heterocyclic group; T, which may be the same or
different, represents a substituted or unsubstituted aliphatic
hydrocarbon group, a substituted or unsubstituted alicyclic
hydrocarbon group, a substituted or unsubstituted aromatic
hydrocarbon group, or a substituted or unsubstituted heterocyclic
group; X represents an oxy group, a thio group, a sulfonyl group, a
carbonyl group, a methylene group, an ethylidene group, a
2,2-propylidene group, a 1,1,1,3,3,3-hexafluoro-2,2-propylidene
group, a 1-phenyl-1,1-ethylidene group, a 1,1-cyclohexylidene group
or a 9,9-fluorenylidene group; Z represents an oxy group or an
imino group, j is an integer of 0 to 3, k, which may be the same or
different, is an integer of 1 to 3, and n, which may be the same or
different, is an integer of 0 to 4.
[0029] The present invention provides an electronic part comprising
the polyimide film pattern formed by the polyimide film
pattern-forming method of the present invention as at least an
insulating member, a protective film member, a liquid crystal
element member or an optical element member.
[0030] The present inventors have paid attentions to the fact that
the carboxyl group of a polyimide precursor (polyamic acid) used as
a base polymer of a photosensitive polyimide has a low acid
dissociation index pKa, which is 3.5 to 4.5, arriving at the
present invention. In the case of using the developing solution of
the present invention for a photosensitive polyimide, it is
possible to dissolve promptly the polyamic acid in the dissolved
portion without impairing the mutual function between the carboxyl
group of the polyimide precursor (polyamic acid) of the undissolved
portion and the dissolution inhibitor.
[0031] To be more specific, the developing solution of the present
invention using an amine compound or a cyclic amine compound having
a base dissociation index pKb of 5 to 8 (an acid dissociation index
pka of 6 to 9) within the aqueous solution at 25.degree. C. makes
it possible to maintain an associated body between the polyamic
acid and the photosensitive dissolution inhibitor without impairing
the association between the carboxyl group of the polyamic acid and
the photosensitive dissolution inhibitor such as a naphthoquinone
diazide compound. At the same time, it is possible to dissolve and
remove selectively the polyamic acid in the portion where the
photosensitive dissolution inhibitor is decomposed by the
photoreaction in the light-exposed portion so as to loose its
dissolution inhibiting function. It follows that the dissolved
portion can be promptly dissolved and removed while scarcely
corroding the film in the undissolved portion.
[0032] As described above, in forming a pattern of a photosensitive
polyimide film, the dissolved portion can be promptly dissolved
while scarcely corroding the film in the undissolved portion by
using the developing solution of the present invention in the
developing step, making it possible to form a fine polyimide film
pattern with a high resolution and a high residual film ratio.
[0033] Incidentally, in the case of using a developing solution
using an amine compound having a base dissociation index pKb that
is less than 5 (or where an acid dissociation index pKa of the
proton complex exceeds 9), which fails to fall within the scope of
the present invention, the basicity of the developing solution is
unduly high so as to inhibit the mutual function between the
carboxyl group of the polyamic acid and the photosensitive
dissolution inhibitor. In this case, the associated body between
the polyamic acid and the photosensitive dissolution inhibitor is
hydrolyzed. As a result, the film in the undissolved portion is
greatly corroded so as to markedly lower the resolution and the
residual film characteristics of the photosensitive polyimide. On
the other hand, in the case of using a developing solution using an
amine compound having a base dissociation index pKb that is larger
than 8 (or where an acid dissociation index pKa of the proton
complex is less than 6), which fails to fall within the scope of
the present invention, the basicity of the developing solution is
unduly weak, resulting in failure to dissolve and remove the
polyamic acid. It follows that it is impossible to form a pattern
of a photosensitive polyimide film.
[0034] Additional objects and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0035] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate presently
preferred embodiments of the invention, and together with the
general description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
[0036] FIG. 1 is a cross-sectional view of a semiconductor element
provided with a passivation film consisting of a polyimide film
pattern which has been obtained by pattern forming method according
to the present invention;
[0037] FIG. 2 is a cross-sectional view of a multi-chip module
provided with an interlayer insulating film consisting of a
polyimide film pattern which has been obtained by pattern forming
method according to the present invention;
[0038] FIG. 3 is a cross-sectional view of an optical waveguide
provided with a polymer core layer consisting of a polyimide film
pattern which has been obtained by pattern forming method according
to the present invention; and
[0039] FIG. 4 is a cross-sectional view of a semiconductor element
having a multilayered wiring structure comprising an interlayer
insulating film consisting of a polyimide film pattern which has
been obtained by pattern forming method according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The developing solution of the present invention will now be
described.
[0041] The developing solution of the present invention for a
photosensitive polyimide consists of an aqueous solution of an
amine compound having a base dissociation index pKb of 5 to 8
within the aqueous solution at 25.degree. C.
[0042] A base dissociation constant Kb of the amine compound A
within an aqueous solution, an acid dissociation constant Ka of the
proton complex HA.sup.+of the amine compound, and an ion product of
water Kw are represented by following formulas, respectively: 1 Kb
= [ HA + ] [ OH - ] [ A ] Ka = [ H + ] [ A ] [ HA + ]
Kw=[H.sup.+].[OH.sup.-]=Ka.Kb
[0043] where [A] is a molar concentration of the amine compound A,
[HA.sup.+] is a molar concentration of the proton complex of the
amine compound, [OH.sup.-] is a molar concentration of a hydroxide
ion, and [H.sup.+] is a molar concentration of a hydrogen ion
(proton).
[0044] The relationship between the base dissociation index pKb of
the amine compound within an aqueous solution and the acid
dissociation index pKa of a proton complex of the amine compound is
represented by the formula given below:
[0045] pKb=-log (Kb)
[0046] =-log (Kw/Ka)
[0047] =-log (Kw)-pKa
[0048] (pKa=-log(Ka))
[0049] Since the ion product of water in an aqueous solution of
25.degree. C. is 1.times.10.sup.-14 (mol.sup.2/L.sup.2), the base
dissociation index pKb at 25.degree. C. is represented as
follows:
pKb=14-pKa
[0050] The amine compound having a base dissociation index pKb of 5
to 8 in an aqueous solution of 25.degree. C. is equal to an amine
compound having the acid dissociation index pKa of the proton
complex of 6 to 9 within an aqueous solution of 25.degree. C.
[0051] The amine compound used in the developing solution of the
present invention is an amine compound having a base dissociation
index pKb of 5 to 8 within an aqueous solution of 25.degree. C.,
i.e., an amine compound having an acid dissociation index pKa of
the proton complex of 6 to 9. Particularly, it is desirable to use
an amine compound having pKa of 6 to 7 within an aqueous solution
of 25.degree. C., (i.e., an amine compound having pKa of the proton
complex of 7 to 8 within an aqueous solution of 25.degree. C). A
developing solution containing the amine compound meeting the
particular requirement is excellent in its resolution
characteristics and residual film characteristics.
[0052] The amine compound used in the present invention, which has
pKb of 5 to 8 within an aqueous solution of 25.degree. C.,
represents a cyclic amine compound or an acyclic amine compound
having pKb of 5 to 8 within an aqueous solution of 25.degree. C. To
be more specific, the particular amine compound used in the present
invention includes, for example, a substituted or unsubstituted
imidazole, a substituted or unsubstituted morpholine, a substituted
or unsubstituted pyrroline, a substituted or unsubstituted
N-(2-cyanoethyl)piperazine, a substituted or unsubstituted
N-propargyl piperazine, a substituted or unsubstituted
N-(2-hydroxyethyl) piperazine, a substituted or unsubstituted
2-anminopropyonitrile, a substituted or unsubstituted propargyl
amine, a substituted or unsubstituted triethanol amine, a
substituted or unsubstituted diethanol amine, and a substituted or
unsubstituted tris (hydroxymethyl)amino methane.
[0053] The substituent groups introduced into the cyclic amine
compounds or the acyclic amine compounds noted above include, for
example, aliphatic hydrocarbon groups given in item (A) below,
alicyclic hydrocarbon groups given in item (B) below, aromatic
hydrocarbon groups given in item (C) below, heterocyclic groups
given in item (D) below, characteristic groups given in item (a)
below, substituted aliphatic hydrocarbon groups in which the
characteristic group in item (a) is substituted in the aliphatic
hydrocarbon groups, substituted alicyclic hydrocarbon groups in
which the characteristic group in item (a) is substituted in the
alicyclic hydrocarbon groups, substituted aromatic hydrocarbon
groups in which the characteristic group in item (a) is substituted
in the aromatic hydrocarbon groups, and substituted heterocyclic
groups in which the characteristic group in item (a) is substituted
in the heterocyclic groups.
[0054] (A) Aliphatic Hydrocarbon Groups:
[0055] The aliphatic hydrocarbon group is at least one aliphatic
hydrocarbon group selected from methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, sec-butyl, tert-butyl, pentyl, tert-pentyl,
isopentyl, neopentyl, hexyl, isohexyl, heptyl, octyl, nonyl, decyl,
vinyl, allyl, isopropenyl, propenyl, methallyl, crotyl, butenyl,
pentenyl, butadienyl, ethynyl, propynyl, butynyl and pentynyl
group.
[0056] (B) Alicyclic Hydrocarbon Groups:
[0057] The alicyclic hydrocarbon group is at least one alicyclic
hydrocarbon group selected from cyclopropyl, cyclobutyl,
cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclopentenyl,
cyclohexenyl, cycloheptenyl, cyclooctenyl, cyclopentadienyl, and
cyclohexadienyl group.
[0058] (C) Aromatic Hydrocarbon Groups:
[0059] The aromatic hydrocarbon group is at least one aromatic
hydrocarbon group selected from benzene ring, naphthalene ring,
anthracene ring, phenanthrene ring, tetralin ring, azulene ring,
biphenylene ring, acenaphthylene ring, acenaphthene ring, fluorene
ring, triphenylene ring, pyrene ring, chrysene ring, picene ring,
perylene ring, benzopyrene ring, rubicene ring, coronene ring,
ovalene ring, indene ring, pentalene ring, heptalene ring, indacene
ring, phenalene ring, fluoranthene ring, acephenanthrylene ring,
aceanthrylene ring, naphthacene ring, pleiadene ring, pentaphene
ring, pentacene ring, tetraphenylene ring, hexaphene ring, hexacene
ring, trinaphthylene ring, heptaphene ring, heptacene ring and
pyranthrene ring.
[0060] (D) Heterocyclic Groups:
[0061] The heterocyclic group is at least one heterocyclic group
selected from pyrrole ring, pyrroline ring, pyrrolidine ring,
indole ring, isoindole ring, indoline ring, isoindoline ring,
indolizine ring, carbazole ring, carboline ring, furan ring,
oxolane ring, coumarone ring, coumaran ring, isobenzofuran ring,
phthalan ring, dibenzofuran ring, thiophene ring, thiolane ring,
benzothiophene ring, dibenzothiophene ring, pyrazole ring,
pyrazoline ring, indazole ring, imidazole ring, imidazoline ring,
imidazolidine ring, benzimidazole ring, benzimidazoline ring,
naphthimidazole ring, oxazole ring, oxazoline ring, oxazolidine
ring, benzoxazole ring, benzoxazoline ring, naphthoxazole ring,
isoxazole ring, benzisoxazole ring, thiazole ring, thiazoline ring,
thiazolidine ring, benzothiazole ring, benzothiazoline ring,
naphthothiazole ring, isothiazole ring, benzisothiazole ring,
triazole ring, benzotriazole ring, oxadiazole ring, thiadiazole
ring, benzoxadiazole ring, benzothiadiazole ring, tetrazole ring,
purine ring, pyridine ring, piperidine ring, quinoline ring,
isoquinoline ring, acridine ring, phenanthridine ring,
benzoquinoline ring, naphthoquinoline ring, naphthylidine ring,
phenanthroline ring, pyridazine ring, pyrimidine ring, pyrazine
ring, piperazine ring, phthalazine ring, quinoxaline ring,
quinazoline ring, cinnoline ring, phenazine ring, perimidine ring,
triazine ring, tetrazine ring, pteridine ring, oxazine ring,
benzoxazine ring, phenoxazine ring, thiazine ring, benzothiazine
ring, phenothiazine ring, oxadiazine ring, thiadiazine ring,
dioxolane ring, benzodioxole ring, dioxane ring, benzodioxane ring,
dithiolane ring, benzodithiol ring, dithiane ring, benzodithiane
ring, pyrane ring, chromene ring, xanthene ring, oxane ring,
chroman ring, isochroman ring, trioxane ring, thiane ring,
trithiane ring, morpholine ring, quinuclidine ring, selenazole
ring, benzoselenazole ring, naphthoselenazole ring, tellurazole
ring and benzotellurazole ring.
[0062] (a) Characteristic Groups:
[0063] The characteristic group is at least one characteristic
group selected from di-substituted amino group (dimethylamino,
diethylamino, dibutylamino, ethylmethylamino, butylmethylamino,
diamylamino, dibenzylamino, diphenethylamino, diphenylamino,
ditolylamino, dixylylamino, methylphenylamino and benzylmethylamino
group); mono-substituted amino group (methylamino, ethylamino,
propylamino, isopropylamino, tert-butylamino, anilino, anisidino,
phenetidino, toluidino, xylidino, pyridylamino, thiazolylamino,
benzylamino and benzylideneamino group); cyclic amino group
(pyrrolidino, piperidino, piperazino, morpholino, 1-pyrrolyl,
1-pyrazolyl, 1-imidazolyl and 1-triazolyl group); acylamino group
(formylamino, acetylamino, benzoylamino, cinnamoylamino,
pyridinecarbonylamino and trifluoroacetylamino group);
sulfonylamino group (mesylamino, ethylsulfonylamino,
phenylsulfonylamino, pyridylsufonylamino, tosylamino, taurylamino,
trifluoromethylsulfonylamino, sulfamoylamino, methylsulfamoylamino,
sulfanylamino and acetylsulfanylamino group); amino group;
hydroxyamino group; ureido group; semicarbazido group; carbazido
group; di-substituted hydrazino group (dimethylhydrazino,
diphenylhydrazino and methylphenylhydrazino group);
mono-substituted hydrazino group (methylhydrazino, phenylhydrazino,
pyridylhydrazino and benzylidenehydrazino group); hydrazino group;
amidino group; oxime group (hydroxyiminomethyl, methoxyiminomethyl,
ethoxyiminomethyl, hydroxyiminoethyl, hydroxyiminopropyl group,
etc.); hydroxyl group; oxy group (methoxy, ethoxy, propoxy, butoxy,
hydroxyethoxy, phenoxy, naphthoxy, pyridyloxy, thiazolyloxy and
acetoxy group); thio group (methylthio, ethylthio, phenylthio,
pyridylthio and thiazolylthio group); alkoxyalkyl group
(hydroxymethyl, hydroxyethyl and hydroxypropyl group); cyano group;
cyanato group; thiocyanato group; nitro group; nitroso group;
mercapto group; halogen group (fluoro, chloro, bromo and iodo
group); carboxyl group and the salts thereof; oxycarbonyl group
(methoxycarbonyl, ethoxycarbonyl, phenoxycarbonyl and
pyridyloxycarbonyl group); aminocarbonyl group (carbamoyl,
methylcarbamoyl, phenylcarbamoyl, pyridylcarbamoyl, carbazoyl,
allophanoyl, oxamoyl and succinamoyl group); thiocarboxyl and the
salts thereof; dithiocarboxyl and the salts thereof; thiocarbonyl
group (methoxythiocarbonyl, methylthiocarbonyl and
methylthiothiocarbonyl group); acyl group (formyl, acetyl,
propionyl, acryloyl, benzoyl, cinnamoyl, pyridinecarbonyl,
thiazolecarbonyl and trifluoroacetyl group); thioacyl group
(thioformyl, thioacetyl, thiobenzoyl and pyridinethiocarbonyl);
sulfino group and the salts thereof; sulfo group and the salts
thereof; sulfinyl group (methylsulfinyl, ethylsulfinyl and
phenylsulfinyl group); sulfonyl group (mesyl, ethylsulfonyl,
phenylsulfonyl, pyridylsulfonyl, tosyl, tauryl,
trifluoromethylsulfonyl, sulfamoyl, methylsulfamoyl, sulfanilyl and
acetylsulfanilyl group); oxysulfonyl group (methoxysulfonyl,
ethoxysulfonyl, phenoxysulfonyl, acetaminopheoxysulfonyl and
pyridyloxysulfonyl group); thiosulfonyl group (methylthiosulfonyl,
ethylthiosulfonyl, phenylthiosulfonyl, acetaminophenylthiosulfonyl
and pyridylthiosulfonyl group); aminosulfonyl group (sulfamoyl,
methylsulfamoyl, dimethylsulfamoyl, ethylsulfamoyl,
diethylsulfamoyl, phenylsulfamoyl, acetaminophenylsulfamoyl and
pyridylsulfamoyl group); ammonio group (trimethylammonio,
ethyldimethylammonio, dimethylsulphenylammonio, pyridinio and
quinolinio group); azo group (phenylazo, pyridylazo and
thiazolylazo group); azoxy group; alkyl halide group (chloromethyl,
bromomethyl, fluoromethyl, dichloromethyl, dibromomethyl,
difluoromethyl, trifluoromethyl, pentafluoroethyl and
heptafluoropropyl group); organosilicic group (silyl, disilanyl,
trimethylsilyl and triphenylsilyl group).
[0064] In the developing solution of the present invention for a
photosensitive polyimide film, it is more desirable to use a
tertiary amine compound as the amine compound. It is particularly
desirable to use as the tertiary amine compound at least one
compound selected from the group consisting of a substituted or
unsubstituted N-substituted imidazole, a substituted or
unsubstituted N-substituted morpholine, a substituted or
unsubstituted N-substituted pyrroline, a substituted or
unsubstituted N-(2-cyanoethyl) piperazine, a substituted or
unsubstituted N-propargyl piperazine, a substituted or
unsubstituted N-(2-hydroxyethyl) piperazine, a substituted or
unsubstituted 2-(N,N-di-substituted amino) propionitrile, a
substituted or unsubstituted N,N-di-substituted propargyl amine, a
substituted or unsubstituted triethanol amine, a substituted or
unsubstituted N-substituted diethanol amine, and a substituted or
unsubstituted N,N-di-substituted tris(hydroxymethyl) amino methane.
The developing solution containing any of these tertiary amines is
excellent in its resolution characteristics and residual film
characteristics.
[0065] The substituent group at the N-position of these compounds
includes, for example, aliphatic hydrocarbon groups given in item
(A) above, alicyclic hydrocarbon groups given in item (B) above,
aromatic hydrocarbon groups given in item (C) above, heterocyclic
groups given in item (D) above, characteristic groups given in item
(a) above, substituted aliphatic hydrocarbon groups in which the
characteristic group in item (a) is substituted in the aliphatic
hydrocarbon groups, substituted alicyclic hydrocarbon groups in
which the characteristic group in item (a) is substituted in the
alicyclic hydrocarbon groups, substituted aromatic hydrocarbon
groups in which the characteristic group in item (a) is substituted
in the aromatic hydrocarbon groups, and substituted heterocyclic
groups in which the characteristic group in item (a) is substituted
in the heterocyclic groups. Particularly, it is desirable to use as
the substituent group a hydrocarbon group having 6 or less carbon
atoms such as a methyl group, an ethyl group, a propyl group, an
isopropyl group, a butyl group, an isobutyl group a sec.-butyl
group, a tert.-butyl group, a pentyl group, a tert.-pentyl group,
an isopentyl group, a neopentyl group, a hexyl group, an isohexyl
group, a cyclopenthyl group, a cyclohexyl group, a phenyl group, a
hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group,
and a hydroxy butyl group.
[0066] The substituent groups for substitution in positions other
than N-position include, for example, aliphatic hydrocarbon groups
given in item (A) above, alicyclic hydrocarbon groups given in item
(B) above, aromatic hydrocarbon groups given in item (C) above,
heterocyclic groups given in item (D) above, characteristic groups
given in item (a) above, substituted aliphatic hydrocarbon groups
in which the characteristic group in item (a) is substituted in the
aliphatic hydrocarbon groups, substituted alicyclic hydrocarbon
groups in which the characteristic group in item (a) is substituted
in the alicyclic hydrocarbon groups, substituted aromatic
hydrocarbon groups in which the characteristic group in item (a) is
substituted in the aromatic hydrocarbon groups, and substituted
heterocyclic groups in which the characteristic group in item (a)
is substituted in the heterocyclic groups.
[0067] The specific examples of the tertiary amine compounds
include, for example, N-methyl imidazole, N-ethyl imidazole,
N-(hydroxyethyl)imidazole- , N-methylmorpholine, N-ethylmorpholine,
N-(hydroxyethyl)morpholine, 2-((dimethylamino)propionitrile,
2-(diethylamino)propionitrile, N,N-dimethylpropargyl amine,
N,N-diethyl propargyl amine, triethanol amine, N-methyl diethanol
amine, N-ethyl diethanol amine, N,N-dimethyl
tris(hydroxymethyl)amino methane,
N-methyl-N'-(hydroxyethyl)piperazine,
N-ethyl-N'-(hydroxyethyl)piperazine, and
N-(hydroxyethyl)-N'-(hydroxyethy- l)piperazine. Among these
compounds, it is desirable to use at least one tertiary amine
compound having pKb of 6 to 7, which is selected from the group
consisting of N-substituted imidazole compound, N-substituted
morpholine compound, 2-(N,N-disubstituted amino)propionitrile
compound, N,N-disubstituted propargyl amine compound and triethanol
amine, because these compounds are excellent in the resolution
characteristics and the residual film characteristics. The specific
compounds of these tertiary amine compounds include, for example,
N-methylimidazole, N-ethylimidazole, N-(hydroxyethyl)imidazole,
N-methylmorpholine, N-ethylmorpholine, N-(hydroxyethyl)morpholine,
2-(dimethylamino)propionit- rile, 2-(diethylamino)propionitrile,
N,N-dimethyl propargyl amine, N,N-diethylpropargyl amine, and
triethanol amine. It is most desirable to use N-substituted
imidazole compounds because the film is unlikely to peel off in the
developing step.
[0068] For preparing the developing solution of the present
invention for a photosensitive polyimide film, it is desirable to
dissolve the amine enumerated above in water and to control the
amine concentration of the solution at 0.1 to 20% by weight. If the
concentration of the amine compound exceeds 20% by weight, the film
is markedly corroded in the undissolved portion, leading to poor
residual film characteristics. On the other hand, where the
concentration of the amine compound is less than 0.1% by weight, it
is difficult to dissolve and remove sufficiently the dissolved
portion. Incidentally, the concentration of the amine compound in
the developing solution of the present invention should desirably
fall within a range of between 1% and 10% by weight.
[0069] For preparing the developing solution of the present
invention, it is desirable to use a pure water or an ultra pure
water prepared by deionization with an ion exchange resin in order
to prevent contamination with an ionic impurity of a silicon wafer
or a substrate for forming a film pattern.
[0070] In order to improve the permeability of the developing
solution or to control the dissolving speed, it is possible to add
to the developing solution of the present invention an alcohol
compound, a surfactant, an inorganic alkaline compound (such as
sodium hydroxide, potassium hydroxide, sodium carbonate, or
potassium carbonate), an organic alkaline compound (such as
tetramethyl ammonium hydroxide, choline, triethyl amine, ethanol
amine, or diethyl ethanol amine), or an acid compound (such as
boric acid, phosphoric acid, carbonic acid, oxime compound,
succinimide compound or a phthalimide compound).
[0071] The developing solution of the present invention can be used
for a photosensitive resin prepared by adding a photosensitive
dissolution inhibitor to an alkali soluble resins such as phenolic
resin, novolak resin, polyacrylic acid, polyimide precursor
(polyamic acid) and benzoxazole precursor and is useful as a
developing solution for, particularly, a photosensitive polyimide
prepared by adding a photosensitive dissolution inhibitor to the
polyimide precursor (polyamic acid).
[0072] A method of forming a polyimide film pattern by using the
developing solution of the present invention will now be
described.
[0073] The method of the present invention for forming a polyimide
film pattern comprises at least steps (I) to (IV), given below:
[0074] (I) The step of coating a substrate surface with a
photosensitive polyimide solution of a positive type containing a
polyimide precursor and a photosensitive dissolution inhibitor,
followed by heating the coating to form a resin layer;
[0075] (II) The step of exposing a desired region of the resin
layer to light;
[0076] (III) The step of developing the resin layer after the light
exposure step with the developing solution of the present
invention; and
[0077] (IV) The step of applying a heat treatment to the resin
layer after the developing step.
[0078] In step (I) noted above, a substrate surface is coated with
a solution of a photosensitive polyimide of a positive type by, for
example, a spin coating method, followed by heating the coating
with a hot plate under temperatures not higher than 160.degree. C.
so as to dry the coating and, thus, to form a resin layer. It is
desirable to set the heating temperature in the heating-drying step
to fall generally within a range of between 70 and 130.degree. C.
However, in order to control the dissolution speed on the occasion
of the development, it is possible to carry out the heating at 130
to 180.degree. C. to imidize partly the polyimide precursor.
Incidentally, it suffices to apply the heating-drying treatment for
0.5 to 60 minutes in general.
[0079] The polyimide precursor in the solution of the
photosensitive polyimide of a positive type used in step (I) noted
above includes polyamic acid, polyamic ester, and a mixture of
polyamic acid and polyamic ester. To be more specific, polyimide
precursor noted above includes, for example, polyamic acid obtained
by the reaction within an organic solvent between tetracarboxylic
dianhydride compound and a diamine compound, polyamic ester
prepared by esterifying a part or all of the carboxylic group of
polyamic acid with a substituted or unsubstituted alkyl group or
tetrahydropyranyl group, and a mixture of such a polyamic acid and
such a polyamic ester.
[0080] It is particularly desirable to use a polyimide precursor
(polyamic acid) having a repeating unit represented by general
formula (1) given below: 3
[0081] where .phi. represents a tetravalent organic group selected
from the group consisting of a substituted or unsubstituted
aliphatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted alicyclic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted heterocyclic group having 1 to 30 carbon atoms, and a
compound radical having an aliphatic hydrocarbon group, an
alicyclic hydrocarbon group, an aromatic hydrocarbon or a
heterocyclic group coupled with each other directly or with a
crosslinking group interposed therebetween, .psi. represents a
divalent organic group selected from the group consisting of a
substituted or unsubstituted aliphatic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted alicyclic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted aromatic hydrocarbon group having 1 to 30 carbon
atoms, a substituted or unsubstituted heterocyclic group having 1
to 30 carbon atoms, and a compound radical having an aliphatic
hydrocarbon group, an alicyclic hydrocarbon group, an aromatic
hydrocarbon or a heterocyclic group coupled with each other
directly or with a crosslinking group interposed therebetween, and
m is a positive integer.
[0082] The polyimide precursor (polyamic acid) represented by
general formula (1) can be synthesized by the reaction within an
organic solvent between a tetracarboxylic dianhydride represented
by general formula (6) given below and a diamine compound
represented by general formula (7) given below: 4
[0083] where .phi. represents a tetravalent organic group selected
from the group consisting of a substituted or unsubstituted
aliphatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted alicyclic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted heterocyclic group having 1 to 30 carbon atoms, and a
compound radical having an aliphatic hydrocarbon group, an
alicyclic hydrocarbon group, an aromatic hydrocarbon or a
heterocyclic group coupled with each other directly or with a
crosslinking group interposed therebetween.
H.sub.2N--.psi.--NH.sub.2 (7)
[0084] where .psi. represents a divalent organic group selected
from the group consisting of a substituted or unsubstituted
aliphatic hydrocarbon group having 1 to 30 carbon atoms, a
substituted or unsubstituted alicyclic hydrocarbon group having 1
to 30 carbon atoms, a substituted or unsubstituted aromatic
hydrocarbon group having 1 to 30 carbon atoms, a substituted or
unsubstituted heterocyclic group having 1 to 30 carbon atoms, and a
compound radical having an aliphatic hydrocarbon group, an
alicyclic hydrocarbon group, an aromatic hydrocarbon or a
heterocyclic group coupled with each other directly or with a
crosslinking group interposed therebetween.
[0085] Examples of tetracarboxylic dianhydride represented by the
general formula (6) are pyromellitic dianhydride,
3-fluoropyromellitic dianhydride, 3,6-difluoropyromellitic
dianhydride, 3-(trifluoromethyl) pyromellitic dianhydride,
3,6-bis(trifluoromethyl)pyromellitic dianhydride,
1,2,3,4-benzenetetracarboxylic dianhydride,
3,3',4,4'-benzophenonetetracarboxylic dianhydride,
2,2',3,3'-benzophenonetetracarboxylic dianhydride,
3,3',4,4'-biphenyltetracarboxylic dianhydride,
3,3",4,4"-terphenyltetraca- rboxylic dianhydride,
3,3"',4,4"'-quaterphenyltetracarboxylic dianhydride,
3,3"",4,4""-quinquephenyltetracarboxylic dianhydride,
2,2',3,3'-biphenyltetracarboxylic dianhydride,
methylene-4,4'-diphthalic dianhydride,
1,1-ethylidene-4,4'-diphthalic dianhydride,
2,2-propylidene-4,4'-diphthalic dianhydride,
1,2-ethylene-4,4'-diphthalic dianhydride,
1,3-trimethylene-4,4'-diphthalic dianhydride,
1,4-tetramethylene-4,4'-diphthalic dianhydride,
1,5-pentamethylene-4,4'-d- iphthalic dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphtha- lic
dianhydride, difluoromethylene-4,4'-diphthalic dianhydride,
1,1,2,2-tetrafluoro-1,2-ethylene-4,4'-diphthalic dianhydride,
1,1,2,2,3,3-hexafluoro-1,3-trimethylene-4,4'-diphthalic
dianhydride,
1,1,2,2,3,3,4,4-octafluoro-1,4-tetramethylene-4,4'-diphthalic
dianhydride,
1,1,2,2,3,3,4,4,5,5-decafluoro-1,5-pentamethylene-4,4'-dipht- halic
dianhydride, oxy-4,4'-diphthalic dianhydride, thio-4,4'-diphthalic
dianhydride, sulfonyl-4,4'-diphthalic dianhydride,
1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride,
1,4-bis(3,4-dicarboxyphe- nyl)benzene dianhydride,
1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride,
1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride,
1,3-bis[2-(3,4-dicarbox- yphenyl)-2-propyl] benzenedianhydride,
1,4-bis[2-(3,4-dicarboxyphenyl)-2-p- ropyl]benzene dianhydride,
bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride,
bis[4-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride,
2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride,
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride,
2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]-1,1,3,3,3-hexafluoropropane
dianhydride,
2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]-1,1,1,3,3,3-hexafluo-
ropropane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane
dianhydride,
1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane
dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride,
1,4,5,8-naphthalenetetracarboxylic dianhydride,
1,2,5,6-naphthalenetetrac- arboxylic dianhydride,
3,4,9,10-perylenetetracarboxylic dianhydride,
2,3,6,7-anthracenetetracarboxylic dianhydride,
1,2,7,8-phenanthrenetetrac- arboxylic dianhydride,
ethylenetetracarboxylic dianhydride, 1,2,3,4-butane tetracarboxylic
dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride,
cyclopentanetetracarboxylic dianhydride,
cyclohexane-1,2,3,4-tetracarboxylic dianhydride,
cyclohexane-1,2,4,5-tetr- acarboxylic dianhydride,
3,3',4,4'-bicyclohexyltetracarboxylic dianhydride,
carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride,
methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride,
1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride,
1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride,
2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic) dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(cyclohexane-1,2-dicarboxy-
lic) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic)
dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic)
dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic)
dianhydride, 2,2'-difluoro-3,3',4,4'-biphenyltetracarboxylic
dianhydride, 5,5'-difluoro-3,3',4,4'-biphenyltetracarboxylic
dianhydride, 6,6'-difluoro-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
2,2',5,5',6,6'-hexafluoro-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
2,2'-bis(trifluoromethyl)-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
5,5'-bis(trifluoromethyl)-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
6,6'-bis(trifluoromethyl)-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
2,2',5,5'-tetrakis(trifluoromethyl)-3,3',4,4'-biphenyltetracarboxylic
dianhydride,
2,2',6,6'-tetrakis(trifluoromethyl)-3,3',4,4'-biphenyltetrac-
arboxylic dianhydride,
5,5',6,6'-tetrakis(trifluoromethyl)-3,3',4,4'-biphe-
nyltetracarboxylic dianhydride,
2,2',5,5',6,6'-hexakis(trifluoromethyl)-3,-
3',4,4'-biphenyltetracarboxylic dianhydride,
oxy-4,4'-bis(3-fluorophthalic- ) dianhydride,
oxy-4,4'-bis(5-fluorophthalic) dianhydride,
oxy-4,4'-bis(6-fluorophthalic) dianhydride,
oxy-4,4'-bis(3,5,6-trifluorop- hthalic) dianhydride,
oxy-4,4'-bis[3-(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[5-(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[6-(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[3,5-bis(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[3,6-bis(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[5,6-bis(trifluoromethyl) phthalic] dianhydride,
oxy-4,4'-bis[3,5,6-tris(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis(3-fluorophthalic) dianhydride,
sulfonyl-4,4'-bis(5-fluo- rophthalic) dianhydride,
sulfonyl-4,4'-bis(6-fluorophthalic) dianhydride,
sulfonyl-4,4'-bis(3,5,6-trifluorophthalic) dianhydride,
sulfonyl-4,4'-bis[3-(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[5-(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[6-(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[3,5-bis(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[3,6-bis(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[5,6-bis(trifluoromethyl) phthalic] dianhydride,
sulfonyl-4,4'-bis[3,5,6-tris(trifluoromethyl) phthalic]
dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(3-fluorophthalic)
dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(5-fluorophth- alic)
dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(6-fluor- ophthalic)
dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(3,-
5,6-trifluorophthalic) dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-
-4,4'-bis[3-trifluoromethyl) phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis[5-(trifluoromethyl)
phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis[6--
(trifluoromethyl) phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propyl-
idene-4,4'-bis[3,5-bis(trifluoromethyl) phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis[3,6-bis(trifluoromethyl)
phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis[5,-
6-bis(trifluoromethyl) phthalic] dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-p-
ropylidene-4,4'-bis[3,5,6-tris(trifluoromethyl) phthalic]
dianhydride,
9-phenyl-9-(trifluoromethyl)xanthene-2,3,6,7-tetracarboxylic
dianhydride,
9,9-bis(trifluoromethyl)xanthene-2,3,6,7-tetracarboxylic
dianhydride, and bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic
dianhydride.
[0086] These tetracarboxylic dianhydride can be used singly or in
the form of a mixture of at least two of these tetracarboxylic
dianhydride.
[0087] The tetracarboxylic dianhydride is used in an amount of at
least 0.8 molar equivalent, preferably at least 0.9 molar
equivalent, of all the acid anhydride components. If the
tetracarboxylic dianhydride is used in an amount smaller than the
amount noted above, the heat resistance of the resultant polyimide
resin is lowered.
[0088] Examples of diamine compound represented by the general
formula (7) are 1,2-phenylenediamine, 1,3-phenylenediamine,
1,4-phenylenediamine, 3,3'-diaminobiphenyl, 3,4'-diaminobiphenyl,
4,4'-diaminobiphenyl, 3,3"-diaminoterphenyl, 4,4"-diaminoterphenyl,
3,3"'-diaminoquaterphenyl, 4,4"'-diaminoquaterphenyl,
3,3""-diaminoquinquephenyl, 4,4""-diaminoquinquephenyl,
oxy-3,3'-dianiline, oxy-4,4'-dianiline, thio-3,3'-dianiline,
thio-4,4'-dianiline, sulfonyl-3,3'-dianiline,
sulfonyl-4,4'-dianiline, methylene-3,3'-dianiline,
methylene-4,4'-dianiline, 1,2-ethylene-3,3'-dianiline,
1,2-ethylene-4,4'-dianiline, 1,1-ethylidene-3,3'-dianiline,
1,1-ethylidene-4,4'-dianiline, 1,3-propylene-3,3'-dianiline,
1,3-propylene-4,4'-dianiline, 2,2-propylidene-3,3'-dianiline,
2,2-propylidene-4,4'-dianiline, difluoromethylene-3,3'-dianiline,
difluoromethylene-4,4'-dianiline,
1,1,2,2-tetrafluoro-1,2-ethylene-3,3'-d- ianiline,
1,1,2,2-tetrafluoro-1,2-ethylene-4,4'-dianiline,
2,2,2-trifluoro-1,1-ethylidene-3,3'-dianiline,
2,2,2-trifluoro-1,1-ethyli- dene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,3'-dianiline- ,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline,
1,1,2,2,3,3-hexafluoro-1,3-propylene-3,3'-dianiline,
1,1,2,2,3,3-hexafluoro-1,3-propylene-4,4'-dianiline,
1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,
1,3-bis(3-aminophenylthio)benzene,
1,3-bis(4-aminophenylthio)benzene,
1,3-bis(3-aminophenylsulfonyl)benzene,
1,3-bis(4-aminophenylsulfonyl)benz- ene,
1,3-bis[2-(3-aminophenyl)-2-propyl]benzene,
1,3-bis[2-(4-aminophenyl)- -2-propyl]benzene,
1,3-bis[2-(3-aminophenyl)-1,1,1,3,3,3-hexafluoro-2-prop- yl]
benzene, 1,3-bis[2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoro-2-propyl]
benzene, 1,4-bis(3-aminophenoxy)benzene,
1,4-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenylthio)benzene,
1,4-bis(4-aminophenylthio)benzene,
1,4-bis(3-aminophenylsulfonyl)benzene,
1,4-bis(4-aminophenylsulfonyl)benz- ene,
1,4-bis[2-(3-aminophenyl)-2-propyl]benzene,
1,4-bis[2-(4-aminophenyl)- -2-propyl]benzene,
1,4-bis[2-(3-aminophenyl)-1,1,1,3,3,3-hexafluoro-2-prop- yl]
benzene, 1,4-bis[2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoro-2-propyl]
benzene, 4,4'-bis(3-aminophenoxy)biphenyl,
4,4'-bis(4-aminophenoxy)biphen- yl,
bis[4-(3-aminophenoxy)phenyl]ether,
bis[4-(4-aminophenoxy)phenyl]ether- ,
bis[4-(3-aminophenoxy)phenyl]sulfone,
bis[4-(4-aminophenoxy)phenyl]sulfo- ne,
2,2-bis[4-(3-aminophenoxy)phenyl]propane,
2,2-bis[4-(4-aminophenoxy)ph- enyl]propane,
2,2-bis[4-(3-aminophenoxy)phenyl-1,1,1,3,3,3-hexafluoropropa- ne,
2,2-bis[4-(4-aminophenoxy)phenyl-1,1,1,3,3,3-hexafluoropropane,
5-fluoro-1,3-phenylenediamine, 2-fluoro-1,4-phenylenediamine,
2,5-difluoro-1,4-phenylenediamine,
2,4,5,6-hexafluoro-1,3-phenylenediamin- e,
2,3,5,6-hexafluoro-1,4-phenylenediamine,
3,3'-diamino-5,5'-difluorobiph- enyl,
4,4'-diamino-2,2'-difluorobiphenyl,
4,4'-diamino-3,3'-difluorobiphen- yl,
3,3'-diamino-2,2',4,4',5,5',6,6'-octafluorobiphenyl,
4,4'-diamino-2,2',3,3',5,5',6,6'-octafluorobiphenyl,
oxy-5,5'-bis(3-fluoroaniline), oxy-4,4'-bis(2-fluoroaniline),
oxy-4,4'-bis(3-fluoroaniline), sulfonyl-5,5'-bis(3-fluoroaniline),
sulfonyl-4,4'-bis(2-fluoroaniline),
sulfonyl-4,4'-bis(3-fluoroaniline),
1,3-bis(3-aminophenoxy)-5-fluorobenzene,
1,3-bis(3-amino-5-fluorophenoxy)- benzene,
1,3-bis(3-amino-5-fluorophenoxy)-5-fluorobenzene,
5-trifluoromethyl-1,3-phenylenediamine,
2-trifluoromethyl-1,4-phenylenedi- amine,
2,5-bis(trifluoromethyl)-1,4-phenylenediamine,
2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl,
3,3'-bis(trifluoromethyl)- -4,4'-diaminobiphenyl,
oxy-5,5'-bis[3-(trifluoromethyl)aniline],
oxy-4,4'-bis[2-(trifluoromethyl)aniline],
oxy-4,4'-bis[3-(trifluoromethyl- )aniline],
sulfonyl-5,5'-bis[3-(trifluoromethyl)aniline],
sulfonyl-4,4'-bis[2-(trifluoromethyl)aniline],
sulfonyl-4,4'-bis[3-(trifl- uoromethyl)aniline],
1,3-bis(3-aminophenoxy)-5-(trifluoromethyl)benzene,
1,3-bis[3-amino-5-(trifluoromethyl)phenoxy]benzene,
1,3-bis[3-amino-5-(trifluoromethyl)phenoxy]-5-(trifluoromethyl)benzene,
3,3'-bis(trifluoromethyl)-5,5'-diaminobiphenyl, bis
(3-aminophenoxy)dimethylsilane, bis (4-aminophenoxy)dimethylsilane,
1,3-bis(3-aminophenyl)-1,1,3,3-tetramethyldisiloxane,
1,3-bis(4-aminophenyl)-1,1,3,3-tetramethyldisiloxane,
methanediamine, 1,2-ethanediamine, 1,3-propanediamine,
1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine,
1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine,
1,10-decanediamine, 1,2-bis(3-aminopropoxy)ethane,
1,3-diaminocyclohexane, 1,4-diaminocyclohexane,
bis(3-aminocyclohexyl)methane, bis(4-aminocyclohexyl)methane,
1,2-bis(3-aminocyclohexyl)ethane, 1,2-bis(4-aminocyclohexyl)ethane,
2,2-bis(3-aminocyclohexyl)propane,
2,2-bis(4-aminocyclohexyl)propane, bis(3-aminocyclohexyl) ether,
bis (4-aminocyclohexyl) ether, bis(3-aminocyclohexyl)sulfone, bis
(4-aminocyclohexyl)sulfone,
2,2-bis(3-aminocyclohexyl)-1,1,1,3,3,3-hexafl- uoropropane,
2,2-bis(4-aminocyclohexyl)-1,1,1,3,3,3-hexafluoropropane,
1,3-xylylenediamine, 1,4-xylylenediamine, 1,8-diaminonaphthalene,
2,7-diaminonaphthalene, 2,6-diaminonaphthalene,
2,5-diaminopyridine, 2,6-diaminopyridine, 2,5-diaminopyrazine,
2,4-diamino-s-triazine, 1,3-bis(aminomethyl)cyclohexane,
1,4-bis(aminomethyl) cyclohexane,
1,4-bis(3-aminopropyldimethylsilyl)benzene, and
1,3-bis(3-aminopropyl)-1,- 1,3,3-tetraphenyl disiloxane.
[0089] These diamine compounds can be used singly or in the form of
a mixture of at least two of these diamine compounds.
[0090] It is desirable to use the diamine compound in an amount of
at least 0.8 molar equivalent, preferably at least 0.9 molar
equivalent, of all the amine compound components. If the diamine
compound is used in an amount smaller than the amount noted above,
the heat resistance of the resultant polyimide resin is
lowered.
[0091] It is possible to use a diamine compound represented by
general formula (8), i.e., bis (aminoalkyl) peralkyl polysiloxane
compound, together with the diamine compounds enumerated above.
5
[0092] where R, which may be the same or different, represents an
alkyl group having 1 to 5 carbon atoms, each of q and r represents
an integer of 1 to 10, and p represents a positive integer.
[0093] Examples of a bis(aminoalkyl)peralkyl polysiloxane compound
represented by the aforementioned general formula (8) are
1,3-bis(aminomethyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(2-aminoethyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(4-aminobutyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(5-aminopentyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(6-aminohexyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(7-aminoheptyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(8-aminooctyl)-1,1,3,3-tetramethyl disiloxane,
1,3-bis(10-aminodecyl)-1,1,3,3-tetramethyl disiloxane,
1,5-bis(3-aminopropyl)-1,1,3,3,5,5-hexamethyl trisiloxane,
1,7-bis(3-aminopropyl)-1,1,3,3,5,5,7,7-octamethyl tetrasiloxane,
1,11-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11-dodecamethyl
hexasiloxane,
1,15-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,-
15-hexadecamethyl octasiloxane, and
1,19-bis(3-aminopropyl)-1,1,3,3,5,5,7,-
7,9,9,11,11,13,13,15,15,17,17,19,19-eicosamethyl decasiloxane.
[0094] The bis (aminoalkyl) peralkyl polysiloxane represented by
general formula (8) produces an effect of improving the adhesivity
and bonding strength of the polyimide resin to, for example, a
glass substrate or a semiconductor substrate such as a silicon
substrate. It is desirable to use these compounds in an amount of
0.02 to 0.2 molar equivalent of all the diamine components. Where
these compounds are used in an amount noted above, the adhesivity
and bonding strength of the resultant polyimide resin to the
substrate is improved. However, if these compounds are used in an
excessively large amount, the heat resistance of the resultant
polyimide resin tends to be lowered.
[0095] Further, a dicarboxylic anhydride or monoamine compound can
be used in the present invention for controlling the degree of
polymerization of the polyamic acid.
[0096] Examples of such a dicarboxylic anhydride are maleic
anhydride, citraconic anhydride, dimethylmaleic anhydride,
ethylmaleic anhydride, diethylmaleic anhydride, propylmaleic
anhydride, butylmaleic anhydride, chloromaleic anhydride,
dichloromaleic anhydride, bromomaleic anhydride, dibromomaleic
anhydride, fluoromaleic anhydride, difluoromaleic anhydride,
trifluoromethylmaleic anhydride, bis(trifluoromethyl)maleic
anhydride, cyclobutanedicarboxylic anhydride,
cyclopentanedicarboxylic anhydride, cyclohexanedicarboxylic
anhydride, tetrahydrophthalic anhydride,
endomethylenetetrahydrophthalic anhydride, methyltetrahydrophthalic
anhydride, methylendomethylenetetrahydrophthalic anhydride,
phthalic anhydride, methylphthalic anhydride, ethylphthalic
anhydride, dimethylphthalic anhydride, fluorophthalic anhydride,
difluorophthalic anhydride, chlorophthalic anhydride,
dichlorophthalic anhydride, bromophthalic anhydride,
dibromophthalic anhydride, nitrophthalic anhydride,
2,3-benzophenonedicarboxylic anhydride,
3,4-benzophenonedicarboxylic anhydride, 3-phenoxyphthalic
anhydride, 4-phenoxyphthalic anhydride, 3-(phenylsulfonyl)phthalic
anhydride, 4-(phenylsulfonyl)phthalic anhydride,
2,3-biphenyldicarboxylic anhydride, 3,4-biphenyldicarboxylic
anhydride, 1,2-naphthalenedicarboxylic anhydride,
2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarbox-
ylic anhydride, 1,2-anthracenedicarboxylic anhydride,
2,3-anthracene dicarboxylic anhydride, 1,9-anthracene dicarboxylic
anhydride, 2,3-pyridine dicarboxylic anhydride, and 3,4-pyridine
dicarboxylic anhydride.
[0097] Examples of the monoamine compound are methylamine,
ethylamine, propylamine, butylamine, pentylamine, hexylamine,
heptylamine, octylamine,
1-(3-aminopropyl)-1,1,3,3,3-pentamethyldisiloxane, vinylamine,
allylamine, glycine, alanine, aminobutyric acid, valine, norvaline,
isovaline, leucine, norleucine, isoleucine, glutamine, glutamic
acid, tryptophan, aminocrotonic acid, aminoacetonitrile,
aminopropionitrile, aminocrotononitrile, cyclopropylamine,
cyclobutylamine, cyclopentylamine, cyclohexylamine,
cycloheptylamine, cyclooctylamine, aminoadamantane,
aminobenzocyclobutane, aminocaprolactam, aniline, chloroaniline,
dichloroaniline, bromoaniline, dibromoaniline, fluoroaniline,
difluoroaniline, nitroaniline, dinitroaniline, toluidine, xylidine,
ethylaniline, anisidine, phenetidine, aminoacetanilide,
aminoacetophenone, aminobenzoic acid, aminobenzaldehyde,
aminobenzonitrile, aminophthalonitrile, aminobenzotrifluoride,
aminostyrene, aminostilbene, aminoazobenzene, aminodiphenyl ether,
aminodiphenyl sulfone, aminobenzamide, aminobenzensulfonamide,
aminophenylmaleimide, aminophenylphthalimide, aminobiphenyl,
aminoterphenyl, aminonaphthalene, aminoanthracene,
aminoanthraquinone, aminofluorene, aminofluorenone,
aminopyrrolidine, aminopiperazine, aminopiperidine,
aminohomopiperidine, aminomorpholine, aminobenzodioxole,
aminobenzodioxane, aminopyridine, aminopyridazine, aminopyrimidine,
aminopyrazine, aminoquinoline, aminocinnoline, aminophthalazine,
aminoquinazoline, aminoquinoxaline, aminopyrrole, aminoimidazole,
aminopyrazole, aminotriazole, aminooxazole, aminoisoxazole,
aminothiazole, aminoisothiazole, aminoindole, aminobenzimidazole,
aminoindazole, aminobenzoxazole, aminobenzothiazole, benzylamine,
phenethylamine, phenylpropylamine, phenylbutylamine,
benzhydrylamine, aminoethyl-1,3-dioxolane, aminoethylpyrrolidine,
aminoethylpiperazine, aminoethylpiperidine, aminoethylmorpholine,
aminopropylimidazole, and aminopropylcyclohexane.
[0098] The mixing ratios of these dicarboxylic anhydride and
monoamine compound may be optionally selected taking the end-use
and viscosity into consideration. For example, these dicarboxylic
anhydride and monoamine compound may be added preferably at a ratio
of 0.02 to 0.4 molar equivalent based on tetracarboxylic
dianhydride and diamine compounds, respectively.
[0099] As for the method of synthesizing the polyamic acid
represented by the aforementioned general formula (1), there is not
any particular restriction. However, it may be preferable to carry
out the polymerization thereof in an organic polar solvent which is
free from water and in an inert gas atmosphere.
[0100] Examples of such an organic polar solvent which may be
employed in this polymerization reaction are N,N-dimethylformamide,
N,N-dimethylacetamide, N,N-diethylacetamide,
N,N-dimethoxyacetamide, N-methyl-2-pyrrolidinone,
N-acetyl-2-pyrrolidinone, N-benzyl-2-pyrrolidinone,
1,3-dimethyl-2-imidazolidinone, hexamethylphosphoric triamide,
N-methyl-.epsilon.-caprolactam, N-acetyl-.epsilon.-caprolactam,
1,2-dimethoxyethane, 1,2-diethoxyethane, bis(2-methoxyethyl) ether,
bis(2-ethoxyethyl) ether, 1,2-bis(2-methoxyethoxy) ethane,
bis[2-(2-methoxyethoxy)ethyl] ether, 1-acetoxy-2-methoxyethane,
1-acetoxy-2-ethoxyethane, (2-acetoxyethyl)(2-methoxyethyl) ether,
(2-acetoxyethyl)(2-ethoxyethyl) ether, methyl 3-methoxypropionate,
tetrahydrofuran, 1,3-dioxane, 1,3-dioxolane, 1,4-dioxane,
pyrroline, pyridine, picoline, dimethylsulfoxide, sulfolane,
.gamma.-butyrolactone, propylene carbonate, phenol, cresol,
acetone, methylethyl ketone, methylisobutyl ketone; cyclohexanone
and acetonylacetone. These organic solvents may be employed singly
or in combination of two or more kinds.
[0101] The temperature of this polymerization reaction may be
generally in the range of -20 to 100.degree. C., preferably in the
range of -5 to 30.degree. C. There is any particular limitation
with respect to the reaction pressure, and hence the reaction can
be performed satisfactorily under the normal pressure. The reaction
time depends on the kinds of tetracarboxylic dianhydride and also
on the kinds of the solvent to be employed in the reaction.
Generally, a time period of 1 to 24 hours may be sufficient for the
reaction.
[0102] The polyamic acid to be obtained in this case should
preferably be 0.3 (dL/g) or more, more preferably in the range of
0.3 (dL/g) to 1.5 (dL/g) in inherent viscosity of 0.5 wt % solution
of the polyamic acid in N,N-dimethylacetamide. The reason for this
is that if the inherent viscosity of the polyamic acid is too low,
i.e. if the polymerization degree of the polyamic acid is too low,
it is difficult to obtain a polyimide resin having a sufficient
heat resistance, whereas if the inherent viscosity of the polyamic
acid is too high, i.e. if the polymerization degree of the polyamic
acid is too high, the handling of it becomes difficult.
[0103] It is desirable to use a polyamic acid synthesized by the
reaction within an organic solvent between a tetracarboxylic
dianhydride and a diamine compound given below as the polyimide
precursor (polyamic acid) represented by general formula (1).
[0104] Examples of tetracarboxylic dianhydride are pyromellitic
dianhydride, 3,3,4,4'-benzophenonetetracarboxylic dianhydride,
3,3,4,4'-biphenyltetracarboxylic dianhydride,
3,3",4,4"-terphenyltetracar- boxylic dianhydride,
methylene-4,4'-diphthalic dianhydride,
1,1-ethylidene-4,4'-diphthalic dianhydride,
2,2-propylidene-4,4'-diphthal- ic dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphthalic dianhydride,
oxy-4,4'-diphthalic dianhydride, thio-4,4'-diphtalic dianhydride,
sulfonyl-4,4'-diphthalic dianhydride,
1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane
dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride,
1,4,5,8-naphthalenetetrac- arboxylic dianhydride,
9-phenyl-9-(trifluoromethyl)xanthene-2,3,6,7-tetrac- arboxylic
dianhydride, and 9,9-bis(trifluoromethyl)xanthene-2,3,6,7-tetrac-
arboxylic dianhydride.
[0105] Examples of diamine compound are 1,3-phenylenediamine,
1,4-phenylenediamine, 3,3'-diaminobiphenyl, 3,4'-diaminobiphenyl,
4,4'-diaminobiphenyl, 3,3"-diaminoterphenyl, 4,4"-diaminoterphenyl,
oxy-3,3'-dianiline, oxy-3,4'-dianiline, oxy-4,4'-dianiline,
sulfonyl-3,3'-dianiline, sulfonyl-4,4'-dianiline,
methylene-3,3'-dianilin- e, methylene-4,4'-dianiline,
2,2-propylidene-3,3'-dianiline, 2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,- 3'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-5,5'-di(2-toluidine),
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-bis(2-aminophenol),
1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene,
1,3-bis[2-(3-aminophenyl)-2-propyl]benzene,
1,3-bis[2-(4-aminophenyl)-2-p- ropyl]benzene,
1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benz- ene,
1,4-bis[2-(3-aminophenyl)-2-propyl]benzene,
1,4-bis[2-(4-aminophenyl)- -2-propyl]benzene,
4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl,
bis[4-(3-aminophenoxy)phenyl] ether,
bis[4-(4-aminophenoxy)phenyl]ether,
bis[4-(3-aminophenoxy)phenyl]sulfone,
bis[4-(4-aminophenoxy)phenyl]sulfone,
2,2-bis[4-(3-aminophenoxy)phenyl]pr- opane,
2,2-bis[4-(4-aminophenoxy)phenyl]propane,
2,2-bis[4-(3-aminophenoxy- )phenyl-1,1,1,3,3,3-hexafluoropropane,
2,2-bis[4-(4-aminophenoxy)phenyl-1,- 1,1,3,3,3-hexafluoropropane,
5-trifluoromethyl-1,3-phenylenediamine,
2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl,
3,3'-bis(trifluoromethyl)- -4,4'-diaminobiphenyl,
oxy-5,5'-bis[3-(trifluoromethyl)aniline], 1,8-diaminonaphthalene,
2,7-diaminonaphthalene, 2,6-diaminonaphthalene,
1,3-bis(3-aminopropyl)-1,1,3,3-tetraphenyl disiloxane,
1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyl disiloxane,
1,5-bis(3-aminopropyl)-1,1,3,3,5,5-hexamethyl trisiloxane,
1,7-bis(3-aminopropyl)-1,1,3,3,5,5,7,7-octamethyl tetrasiloxane,
1,11-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11-dodecamethyl
hexasiloxane,
1,15-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,-
15-hexadecamethyl octasiloxane, and
1,19-bis(3-aminopropyl)-1,1,3,3,5,5,7,-
7,9,9,11,11,13,13,15,15,17,17,19,19-eicosamethyl decasiloxane.
[0106] Particularly, a polyamic acid systhesized by reacting in an
organic solvent 1.0 molar equivalent of tetracarboxlic dianhydride
given below, 0.8 to 1.2 molar equivalent of diamine compound given
below, and 0.02 to 0.2 molar equivalent of siloxane compound given
below.
[0107] Examples of tetracarboxylic dianhydride used for the
synthesis are materials containing at least 0.6 molar equivalent of
at least one kind of diphthalic dianhydride derivative selected
from the group consisting of 3,3',4,4'-benzophenone tetracarboxylic
dianhydride, methylene-4,4'-diphtalic dianhydride,
1,1-ethylidene-4,4'-diphthalic dianhydride,
2,2-propylidene-4,4'-diphthalic dianhydride,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphthalic dianhydride,
oxy-4,4'-diphthalic dianhydride, thio-4,4'-diphthalic dianhydride,
sulfonyl-4,4'-diphthalic dianhydride,
1,3-bis(3,4-dicarboxyphenyl)-1,1,3,- 3-tetramethyl disiloxane
dianhydride, 9-phenyl-9-(trifluoromethyl)xanthene-
-2,3,6,7-tetracarboxylic dianhydride, and
9,9-bis(trifluoromethyl)xanthene- -2,3,6,7-tetracarboxylic
dianhydride.
[0108] Examples of diamine compound are materials containing at
least 0.6 molar equivalent of at least one kind of a dianiline
derivative selected from the group consisting of
oxy-3,3'-dianiline, oxy-3,4'-dianiline, oxy-4,4'-dianiline,
sulfonyl-3,3'-dianiline, sulfonyl-4,4'-dianiline,
methylene-3,3'-dianiline, methylene-4,4'-dianiline,
2,2-propylidene-3,3'-dianiline, 2,2-propylidine-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,3'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-5,5'-di(2-toluidine), and
1,1,1,3,3,3-hexafluoro-2-2-propylidene-4,4'-bis
(2-aminophenol).
[0109] The siloxane compounds are materials containing at least
0.02 molar equivalent of at least one compound selected from the
group consisting of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyl
disiloxane, 1,5-bis(3-aminopropyl)-1,1,3,3,5,5-hexamethyl
trisiloxane, 1,7-bis(3-aminopropyl)-1,1,3,3,5,5,7,7-octamethyl
tetrasiloxane, and
1,11-bis(3-aminopropyl)-1,1,3,3,5,5,7,7,9,9,11,11-dodecamethyl
hexasiloxane.
[0110] These polyamic acids are excellent in the dissolving speed
in the developing solution, the contrast between the light-exposed
portion and the non-exposed portion and the bonding strength to the
substrate and, thus, are particularly desirable.
[0111] The photosensitive dissolution inhibitor used in the
photosensitive polyimide of a positive type is a substituted or
unsubstituted compound selected from the group consisting of
1,2-naphtoquinone-2-diazide compound such as
1,2-naphthoquinone-2-diazide-4-sulfonic ester compound,
1,2-naphthoquinone-2-diazide-5-sulfonic ester compound,
1,2-naphthoquinone-2-diazide-4-sulfonamide compound, or
1,2-naphthoquinone-2-diazide-sulfonamide compound;
1,2-naphthoquinone-1-diazide compound such as
1,2-naphthoquinone-1-diazid- e-4-sulfonic ester compound,
1,2-naphthoquinone-1-diazide-5-sulfonic ester compound,
1,2-naphthoquinone-1-diazide-4-sulfonamide compound, or
1,2-naphthoquinone-1-diazide-5-sulfonamide compound;
quinoline-3,4-quinone-3-diazide compound;
1,4-naphthoquinone-1-diazide compound; 1,4-benzoquinone-1-diazide
compound; 1,4-benzoquinone-1-diazide compound;
pyridine-3,4,-quinone-3-diazide compound; and
1,4-dihydro-4-(2-nitrophenyl) pyridine compound (nifedipine,
etc.).
[0112] It is desirable to use as the photosensitive dissolution
inhibitor naphthoquinone diazide sulfonic ester compound or
naphthoquinone diazide sulfonic acid amide compound obtained by the
reaction between a phenol compound or an aniline compound and
naphthoquinone diazide sulfonyl chloride compound.
[0113] Specific examples of the naphthoquinone diazide sulfonic
ester compound include the compound obtained by the reaction
between the phenol compound enumerated in group (E) given below and
the naphthoquinone diazide sulfonyl chloride compounds enumerated
in group (F) given below, said reaction being carried out within
water or an organic solvent in the presence of a basic catalyst
such as sodium hydroxide, potassium hydroxide, potassium carbonate
or triethyl amine so as to sulfonic acid esterify the hydroxyl
group.
[0114] On the other hand, the specific examples of the
naphthoquinone diazide sulfonic acid amide compound include
compounds obtained by the reaction between the aniline compounds
enumerated in group (F) given below and the naphthoquinone diazide
sulfonyl chloride compounds enumerated in group (G) given below.
The reaction is carried out within water or an organic solvent in
the presence of a basic catalyst such as sodium hydroxide,
potassium hydroxide, potassium carbonate or triethyl amine to
subject the amino group to sulfonic acid amidation.
[0115] (E) Phenol Compounds:
[0116] The phenol compounds noted above include a substituted or
unsubstituted compound selected from the group consisting of
phenol, pyrocatechol, resorcinol, hydroquinone, benzene triol,
benzene tetraol, hydroxybenzyl alcohol, hydroxybenzene dimethanol,
hydroxybenzene trimethanol, hydroxyphenetyl alcohol, biphenol,
oxydiphenol, thiodiphenol, sulfonyl diphenol, dihydroxy
benzophenone, trihydroxy benzophenone, tetrahydroxy benzophenone,
methylene diphenol, ethylene diphenol, ethylidene diphenol,
propylidene diphenol, butylidene diphenol, pentylidene diphenol,
methylpropylidene diphenol, methylpentylidene diphenol,
hexafluoropropylidene diphenol, phenyl ethylidene diphenol,
cyclopentylidene diphenol, cyclohexylidene diphenol, fluorenylidene
diphenol, dimethyl silylene diphenol, tris(hydroxyphenyl)methane,
tris(hydroxyphenyl)ethane, tris(hydroxyphenyl)propane,
tris(4-hydroxyphenyl)butane, phenyl tris(hydroxyphenyl)methane,
cyclohexyl tris(hydroxyphenyl)methane,
bis(hydroxyphenyl)(dihydroxyphenyl- )methane,
bis(hydroxyphenyl)(dihydroxyphenyl)ethane,
bis(hydroxyphenyl){[(hydroxyphenyl)propyl]phenyl} methane,
bis(hydroxyphenyl){[(hydroxyphenyl)propyl]phenyl}ethane,
bis(hydroxyphenyl){[(hydroxyphenyl)propyl]phenyl} propane,
bis(hydroxyphenyl){[(hydroxyphenyl)propyl]phenyl}butane,
bis(hydroxyphenyl){[(hydroxyphenyl)propyl]phenyl} phenylmethane,
bis(hydroxyphenyl)cyclohexyl{[(hydroxyphenyl)propyl]
phenyl}methane, bis(hydroxyphenoxy)benzene,
bis(hydroxyphenylpropyl)benzene, bis(hydroxybenzyl) phenol,
bis(hydroxybenzyl)benzene diol, bis(hydroxybenzyl)benzene triol,
tris(hydroxybenzyl)benzene diol, tetrakis(hydroxyphenyl)ethane,
bis[bis(hydroxyphenyl)methyl]benzene, naphthol, naphthalene diol,
naphthalene triol, 3,3-bis(hydroxyphenyl)oxin- dole, and
3,3-bis(hydroxyphenyl)phthalide.
[0117] (F) Aniline Compounds:
[0118] The aniline compounds noted above include a substituted or
unsubstituted compound selected from the group consisting of
aniline, phenylene diamine, benzene triamine, benzene tetraamine,
hydroxyaniline, benzidine, oxy dianiline, thio dianiline, sulfonyl
dianiline, diamino benzophenone, methylene dianiline, ethylene
dianiline, ethylidene dianiline, propylidene dianiline, butylidene
dianiline, pentylidene dianiline, methylpropylidene dianiline,
methylpentylidene dianiline, hexafluoropropylidene dianiline,
phenylethylidene dianiline, cyclopentylidene dianiline,
cyclohexylidene dianiline, fluorenylidene dianiline, dimethyl
silylene dianiline, tris(aminophenyl)methane,
tris(aminophenyl)ethane, tris(aminophenyl)propane,
tris(4-aminophenyl)butane, phenyl tris(aminophenyl)methane,
cyclohexyl tris(aminophenyl)methane, bis(aminophenyl)benzene,
tris(aminophenyl)methane, tris(aminophenyl)ethane, naphthylamine,
naphthalene diamine, and naphthalene triamine.
[0119] (G) Naphthoquinone diazide sulfonyl chloride compound:
[0120] The naphthoquinone diazide sulfonyl chloride compound used
in the present invention include, for example,
1,2-naphthoquinone-2-diazide-4-su- lfonyl chloride,
1,2-naphthoquinone-2-diazide-5-sulfonyl chloride,
1,2-naphthoquinone-1-diazide-4-sulfonyl chloride and
1,2-naphthoquinone-1-diazide-5-sulfonyl chloride.
[0121] In view of the sensitivity and the resolution, it is
desirable to use the naphthoquinone diazide compounds represented
by general formulas (2) to (5) given below as the photosensitive
dissolution inhibitor. 6
[0122] where Q, which may be the same or different, represents a
hydrogen atom, 1,2-naphthoquinone-2-diazide-4-sulfonyl group or
1,2-naphthoquinone-2-diazide-5-sulfonyl group, at least one Q in
the general formulas representing
1,2-naphthoquinone-2-diazide-4-sulfonyl group or
1,2-naphthoquinone-2-diazide-5-sulfonyl group, R, which may be the
same or different, represents a hydrogen atom, a substituted or
unsubstituted aliphatic hydrocarbon group, alicyclic hydrocarbon
group, aromatic hydrocarbon group or heterocyclic group, T, which
may be the same or different, represents a substituted or
unsubstituted aliphatic hydrocarbon group, alicyclic hydrocarbon
group, aromatic hydrocarbon group or heterocyclic group, X, which
may be the same or different, represents an oxy group, a thio
group, a sulfonyl group, a carbonyl group, a methylene group, an
ethylidene group, 2,2-propylidene group,
1,1,1,3,3,3-hexafluoro-2,2-propylidene group,
1-phenyl-1,1-ethylidene group, 1,1-cyclohexylidene group, or
9,9-fluorenylidene group, Z, which may be the same or different,
represents an oxy group or an imino group, j is an integer of 0 to
3, k, which may be the same or different, is an integer of 1 to 3,
and n, which may be the same or different, is an integer of 0 to
4.
[0123] The substituent R of the naphthoquinone diazide compounds
represented by general formulas (2) to (5) given above, which may
be the same or different, represents a hydrogen atom, a substituted
or unsubstituted aliphatic hydrocarbon group, alicyclic hydrocarbon
group, aromatic hydrocarbon group or heterocyclic group. To be more
specific, R represents an aliphatic hydrocarbon group included in
group (A) given previously, an alicyclic hydrocarbon group included
in group (B) given previously, an aromatic hydrocarbon group
included in group (C) given previously, a heterocyclic group
included in group (D) given previously, and substituted aliphatic
hydrocarbon group, alicyclic hydrocarbon group, aromatic
hydrocarbon group or heterocyclic group, in which the
characteristic group included in group (a) given previously is
substituted in the aliphatic hydrocarbon group, alicyclic
hydrocarbon group, aromatic hydrocarbon group or heterocyclic
group. Particularly, R in the general formulas (2) to (5) should
desirably be a hydrogen atom or a hydrocarbon group having not more
than 6 carbon atoms such as methyl, ethyl, propyl, isopropyl,
butyl, isobutyl, sec.-butyl, tert.-butyl, pentyl, tert.-pentyl,
isopentyl, neopentyl, hexyl, isohexyl, cyclohexyl, cyclopentyl,
cyclohexyl, or phenyl.
[0124] The substituent T of the naphthoquinone diazide compounds
represented by general formulas (2) to (5), which may be the same
or different, represents a substituted or unsubstituted aliphatic
hydrocarbon group, alicyclic hydrocarbon group, aromatic
hydrocarbon group, heterocyclic group, or a characteristic
group.
[0125] The substituent T of the naphthoquinone diazide sulfonic
ester compounds or the naphthoquinone diazide sulfonic acid amide
compounds represented by general formulas (2) to (5), which may be
the same or different, represents a substituted or unsubstituted
aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic
hydrocarbon group, heterocyclic group, or a characteristic group,
or to be more specific, the aliphatic hydrocarbon groups included
in the group (A) given previously, the alicyclic hydrocarbon group
included in group (B) given previously, the aromatic hydrocarbon
group included in the group (C) given previously, the heterocyclic
group included in the group (D) given previously, the
characteristic group included in group (a) given previously, and
the substituted aliphatic hydrocarbon group, the substituted
alicyclic hydrocarbon group, the substituted aromatic hydrocarbon
group, or the substituted heterocyclic group, in which the
characteristic group included in group (a) is substituted in the
aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the
aromatic hydrocarbon group, or heterocyclic group. Particularly, it
is desirable for the substituent T to be a hydrocarbon group having
not more than 6 carbon atoms such as methyl, ethyl, propyl,
isopropyl, butyl, isobutyl, sec.-butyl, tert.-butyl, pentyl,
tert.-pentyl, isopentyl, neopentyl, hexyl, isohexyl, cyclopentyl,
cyclohexyl, or phenyl.
[0126] The specific examples of the naphthoquinone diazide
compounds represented by general formulas (2) to (5) includes the
compounds obtained by the reaction between the phenol compounds
included in group (H) given below or the aniline compounds included
in group (I) given below and
1,2-naphthoquinone-2-diazide-4-sulfonyl chloride or 1,2-
naphthoquinone-2-diazide-5-sulfonyl chloride. The reaction is
carried out within water or an organic solvent in the presence of a
basic catalyst so as to subject the hydroxyl group or amino group
to sulfonic acid esterification or sulfonic acid amidation. The
basic catalyst used in the reaction includes, for example, sodium
hydroxide, potassium hydroxide, potassium carbonate, and triethyl
amine.
[0127] It is desirable to introduce the naphthoquinone diazide
sulfonyl group into the substituent T included in the general
formula in an amount of at least 40 mol % in view of the
dissolution inhibiting effect.
[0128] (H) Phenol compounds:
[0129] The phenol compounds used in the reaction include, for
example, tris(4-hydroxyphenyl)methane,
1,1,1-tris(4-hydroxyphenyl)ethane,
1,1,1-tris(4-hydroxyphenyl)propane,
1,1,1-tris(4-hydroxyphenyl)butane,
phenyl-tris(4-hydroxyphenyl)methane,
cyclohexyl-tris(4-hydroxyphenyl)meth- ane,
tris(4-hydroxy-2-methylphenyl)methane,
1,1,1-tris(4-hydroxy-2-methylp- henyl)ethane,
tris(4-hydroxy-3-methylphenyl)methane,
1,1,1-tris(4-hydroxy-3-methylphenyl)ethane,
bis(4-hydroxyphenyl)(2-hydrox- yphenyl)methane,
bis(4-hydroxyphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxyphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-2-methylp- henyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-2-methylphenyl)(3-hydroxyphe- nyl)methane,
bis(4-hydroxy-2-methylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-2-methylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-3-methylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-3-methylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-3-methylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-3-methylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-3,5-dimethylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-3,5-dimethylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-3,5-dimethylphenyl)(4-dihydroxyphenyl)methane,
bis(4-hydroxy-3,5-dimethylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-3-isopropylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-3-isopropylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-3-isopropylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-3-isopropylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-3-t-butylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-3-t-butylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-3-t-butylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-3-t-butylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-3-cyclohexylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-3-cyclohexylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-3-cyclohexylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-3-cyclohexylphenyl)(3,4-dihydroxyphenyl )methane,
bis(4-hydroxy-5-cyclohexylphenyl-2-methylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexyl-2-methylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexy-2-methylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexyl-2-methylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-2,3,5-trimethylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-2,3,5-trimethylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-2,3,5-trimethylphenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-2,3,5-trimethylphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxyphenyl){4-[2-(4-hydroxyphenyl)-2-propyl]phenyl}methane,
1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4-hydroxyphenyl)-2-propyl]phenyl}ethane-
,
1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4-hydroxyphenyl)-2-propyl]phenyl}propa-
ne,
1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4-hydroxyphenyl)-2-propyl]phenyl}but-
ane,
1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4-hydroxyphenyl)-2-propyl]phenyl}-1-
-phenylmethane,
1,1-bis(4-hydroxyphenyl)-1-cyclohexyl-1-{4-[2-(4-hydroxyph-
enyl)-2-propyl]phenyl}methane, oxy-4,4'-diphenol,
thio-4,4'-diphenol, sulfonyl-4,4'-diphenol,
methylene-4,4'-diphenol, 1,1-ethylidene-4,4'-diph- enol,
2,2-propylidene-4,4'-diphenol,
1,1,1,3,3,3-hexafluoro-2,2-propyliden- e-4,4'-diphenol,
1-phenyl-1,1-ethylidene-4,4'-diphenol,
2,2-propylidene-4,4'-bis(2-methylphenol),
2,2-propylidene-4,4'-bis(3-meth- ylphenol),
2,2-propylidene-4,4'-bis(3,5-dimethylphenol),
2,2-propylidene-4,4'-bis(3-isopropylphenol),
2,2-propylidene-4,4'-bis(3-t- -butylphenol),
2,2-propylidene-4,4'-bis(3-cyclohexylphenol),
2,2-propylidene-4,4'-bis(3-phenylphenol),
cyclohexylidene-4,4'-diphenol,
cyclohexylidene-4,4'-bis(2-methylphenol),
cyclohexylidene-4,4'-bis(3-meth- ylphenol),
cyclohexylidene-4,4'-bis(3,5-dimethylphenol),
cyclohexylidene-4,4'-bis(3-isopropylphenol),
cyclohexylidene-4,4'-bis(3-t- -butylphenol),
cyclohexylidene-4,4'-bis(3-cyclohexylphenol),
cyclohexylidene-4,4'-bis(3-phenylphenol),
9,9-flurorenylidene-4,4'-diphen- ol, 4,4'-dihydroxy benzophenone,
2,3,4-trihydroxy benzophenone, 2,4,4'-trihydroxy benzophenone,
2,3,4,4'-tetrahydroxy benzophenone,
3,3-bis(4-hydroxyphenyl)phthalide,
3,3-bis(4-hydroxy-2-methylphenyl)phtha- lide, and
3,3-bis(4-hydroxy-3-methylphenyl)phthalide.
[0130] (I) Aniline compound:
[0131] The aniline compounds used in the reaction include, for
example, oxy-3,3-dianiline, oxy-3,4-dianiline, oxy-4,4-dianiline,
thio-4,4-dianiline, sulfonyl-3,3-dianiline, sulfonyl-4,4-dianiline,
3,3-diamino benzophenone, 4,4-diamino benzophenone,
methylene-4,4-dianiline, 2,2-propylidene-4,4-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-3,3-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4-dianiline,
1,1,1,3,3,3-hexafluoro-2,2-propylidene-5,5-bis(2-methylaniline),
phenylethylidene-4,4-dianiline, cyclohexylidene-4,4-dianiline, and
9,9-fluorenylidene-4,4-dianiline.
[0132] In view of the dissolution inhibiting properties and the
light transmitting properties, the naphthoquinone diazide compound
used in the present invention should desirably be consist of
1,2-naphthoquinone diazide-5-sulfonic ester compound or
1,2-naphthoquinone diazide-5-sulfonic acid amide compound having an
average introduction rate of at least 50 mol % and synthesized by
the reaction between the phenol compound or aniline compound given
below with 1,2-naphthoquinone diazide-5-sulfonyl chloride compound.
The term average introduction rate noted above denotes the
introduction rate of 1,2-naphthoquinone diazide-5-sulfonyl group in
the substituent Q included in the general formulas.
[0133] The phenol compounds noted above include, for example,
tris(4-hydroxyphenyl) methane, 1,1,1-tris(4-hydroxyphenyl)ethane,
bis(4-hydroxyphenyl)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohe-
xyl-2-methylphenyl)(2-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexyl-2--
methylphenyl)(3-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexyl-2-methyl-
phenyl)(4-hydroxyphenyl)methane,
bis(4-hydroxy-5-cyclohexyl-2-methylphenyl-
)(3,4-dihydroxyphenyl)methane,
bis(4-hydroxyphenyl){4-[2-(4-hydroxyphenyl)- -2-propyl]
phenyl}methane, 1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4-hydroxyphen-
yl)-2-propyl] phenyl}ethane, 2,2-propyliden-4,4'-diphenol,
1,1,1,3,3,3-hexafluoro-2,2-propyliden-4,4'-diphenol,
3,3-bis(4-hydroxyphenyl)phthalide,
3,3-bis(4-hydroxy-2-methylphenyl)phtha- lide, and
3,3-bis(4-hydroxy-3-methylphenyl) phthalide.
[0134] On the other hand, the aniline compounds noted above
include, for example, oxy-3,3-dianiline, oxy-3,4-dianiline,
oxy-4,4-dianiline, sulfonyl-3,3-dianiline, sulfonyl-4,4-dianiline,
2,2-propylidene-4,4-diani- line,
1,1,3,3,3-hexafluoro-2,2-propylidene-3,3-dianiline,
1,1,3,3,3-hexafluoro-2,2-propylidene-4,4-dianiline,
1,1,3,3,3-hexafluoro-2,2-propylidene-5,5-bis(2-methylaniline),
cyclohexylidene-4,4-dianiline, and
9,9-fluorenylidene-4,4-dianiline.
[0135] It is possible to use as desired a photosensitizer in the
solution of the photosensitive polyimide of a positive type for
increasing the sensitivity of the solution. The photosensitizer
used in the present invention includes, for example, acetophenone,
benzophenone, benzoin, 2-methylbenzoin, benzoin isopropyl ether,
anthrone, 1,9-benzoanthrone, anthracene, phenanthrene quinone,
pyrene-1,6-quinone, 9-fluorenone, 1,2-benzoanthraquinone,
anthanthrone, 2-chlorobenzanthraquinone, 2-bromobenzanthraquinone,
2-chloro-1,8-phthaloylnaphthalene, Michler's ketone,
4,4'-bis(diethylamino)benzophenone, benzoin methylether, benzyl
dimethylketal, 2-methyl-1-[4-(methylthio)phenyl]
-2-morpholino-1-propanon- e, 1-hydroxycyclohexyl phenylketone,
ethyl N,N-dimethylamino benzoate, acridine, cyanoacridine,
nitropyrene, 1,8-dinitropyrene, 5-nitroacenaphthene,
2-nitrofluorene, 2-t-buryl-9,10-anthraquinone, and N-phenyl
maleimide.
[0136] These photosensitizers are used singly or in the form of a
mixture of at least two compounds thereof in an amount of at least
0.01% by weight, preferably 0.1 to 20% by weight, based on the
amount of the polyimide precursor. If the amount of the
photosensitizer fails fall within the range specified in the
present invention, adverse effects are given to the developing
properties and the film forming properties.
[0137] Also, it is possible to add, as desired, a dye, a surfactant
and an alkali soluble resin to the solution of the photosensitive
polyimide of a positive type.
[0138] In preparing the solution of the photosensitive polyimide of
a positive type, a photosensitive dissolution inhibitor is
dissolved first in a solution of the polyimide precursor, followed
by diluting the solution as desired with a suitable organic
solvent. Further, a photosensitizer, a dye, a surfactant, an alkali
soluble resin are dissolved, as desired, in the resultant solution,
followed by removing fine impurities by, for example, filtration,
if necessary. It is desirable to add the photosensitive dissolution
inhibitor in an amount of 1 to 50% by weight, preferably 10 to 40%
by weight, based on the amount of the polyimide precursor.
[0139] The organic solvent used in the present invention includes,
for example, N,N-dimethylformamide, N,N-dimethylacetamide,
N,N-diethylacetamide, N,N-dimethoxyacetamide,
N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone,
N-benzyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolid- inone,
hexamethylphosphoric triamide, N-methyl-.epsilon.-caprolactam,
N-acetyl-.epsilon.-caprolactam, 1,2-dimethoxyethane,
1,2-diethoxyethane, bis(2-methoxy ethyl)ether,
bis(2-ethoxyethyl)ether, 1,2-bis(2-methoxy ethoxy)ethane,
bis([2-(2-methoxyethoxy)ethyl]ether, 1-acetoxy-2-methoxyethane,
1-acetoxy-2-etoxyethane, (2-acetoxyethyl)(2-methoxyethyl)ether,
(2-acetoxyethyl)(2-ethoxyethyl)eth- er, methyl 3-methoxypropionate,
tetrahydrofuran, 1,3-dioxane, 1,3-dioxolane, 1,4-dioxolane,
pyrroline, pyridine, picoline, dimethylsulfoxide, sulfolane,
.gamma.-butyrolactone, propylene carbonate, phenol, cresol,
acetone, methylethylketone, methylisobutylketone, cyclohexanone,
and acetonitrile. These organic solvents can be used singly or in
the form of a mixture of at least two of these compounds.
[0140] It is desirable to prepare the solution of the
photosensitive polyimide of a positive type as follows. In the
first step, the naphthoquinone compound represented by general
formulas (2) to (5) is added to the solution of polyamic acid
represented by general formula (1), followed by stirring the
solution with a mechanical stirrer, a magnetic stirrer, a
reciprocating shaker, a mix rotor, etc. It is possible to dilute
the solution with a suitable solvent, if necessary. The addition
amount of the naphthoquinone diazide compound is 1 to 50% by weight
based on the amount of the polyimide precursor. Further, a
photosensitizer, a dye, a surfactant, an alkali soluble resin are
added and dissolved, as desired, followed by removing the fine
impurities by, for example, filtration, as desired, so as to
prepare a solution of the photosensitive polyimide of a positive
type.
[0141] In step (II) described previously, the resin layer is
irradiated with an energy ray such as a visible light, an infrared
ray, an ultraviolet light, EB or an X-ray through a photo mask
having a predetermined pattern so as to expose a desired region of
the resin layer to light. Any of contact light exposure and
projecting light exposure can be employed in this light exposure
step.
[0142] Incidentally, it is possible to apply as desired a PEB
(post-exposure baking) using, for example, a hot plate during or
after the light exposure step in order to improve the resolution
characteristics. It is desirable to apply PEB at about 80 to
160.degree. C. for about 10 seconds to 10 minutes.
[0143] In step (III) described previously, the resin layer is
developed with the developing solution of the present invention for
a photosensitive polyimide after the light exposure step (or after
the PEB step, as desired). The light-exposed portion of the resin
layer is dissolved and removed by the developing treatment so as to
form a desired pattern of a positive type. The developing treatment
is performed by, for example, an immersion method, a spray
developing method or a paddle developing method.
[0144] After the developing step, it is desirable to apply a
rinsing treatment with water, alcohol, water-alcohol mixed
solution, etc. for removing the residual developing solution.
[0145] In step (IV) described previously, a heat treatment is
applied after the developing step to the resin layer having a
pattern formed thereon at 120 to 450.degree. C. by using a hot
plate or an oven so as to dry the developing solution or the
rinsing solution, to convert the polyimide precursor into a
polyimide film by imidization under heat and to thermally decompose
and remove the photosensitive dissolution inhibitor. Incidentally,
where the heat treatment is applied at a high temperature, e.g.,
not lower than 300.degree. C., it is desirable to apply the heat
treatment under vacuum or in the presence of an inert gas stream
such as a nitrogen gas stream or an argon gas stream so as to
prevent the polyimide film from being thermally oxidized.
[0146] The electronic part of the present invention is featured in
that the electronic part comprises the polyimide film obtained by
the pattern forming method of the polyimide film described above as
an insulating member, a protective film member, a liquid crystal
element member or an optical element member. The particular
electronic part includes, for example, an LSI device in which an
interlayer insulating film includes a multi-wiring layer formed of
a polymer resin such as polyimide and interposed between conductor
layers or semiconductor layers, a semiconductor device using a
passivation film made of a polymer resin such as polyimide as a
humidity resistant insulating protective layer interposed between
conductor layers or semiconductor layers, an electronic part using
a polymer resin such as polyimide for forming an insulating
protective film interposed between conductor layers or
semiconductor layers, as electronic part in which an insulating
protective layer made of a polymer resin such as polyimide is
interposed between a silicon wafer and a wiring layer or between
adjacent wiring layers, a thin film magnetic head in which an
insulating protective film made of a polymer film such as polyimide
is interposed between the substrate material and the wiring layer
or between the adjacent wiring layers, a high density printed
circuit board in which an insulating protective layer made of a
polymer resin such as polyimide is interposed between the substrate
material and the wiring layer or between the adjacent wiring
layers, a magnetic bubble memory in which an insulating protective
layer made of a polymer resin such as polyimide is interposed
between the substrate material and the wiring layer or between the
adjacent wiring layers, a solar battery in which an insulating
protective layer made of a polymer resin such as polyimide is
interposed between the substrate material and the wiring layer or
between the adjacent wiring layers, and an optical element using a
polymer resin such as polyimide as an optical waveguide.
[0147] The present invention will now be described based on
specific examples of the present invention. However, these examples
should not be construed as limiting the present invention.
[0148] (1) Synthesis of polyamic acid:
[0149] Polyamic acid was synthesized as follows by using raw
materials mixed together at a predetermined mixing ratio (shown in
molar equivalent) as shown in the following Table 1. First of all,
50 ml of N,N-dimethylacetamide was placed under an argon gas
atmosphere into a separable flask cooled down to -5 to 5.degree. C.
by using a cooling medium. Then, a predetermined amount of
tetracarboxylic dianhydride compound was added to the flask and
dissolved with stirring to obtain a solution. Subsequently, a
predetermined amount of diamine compound was dissolved in 50 ml of
N,N-dimethylacetamide to obtain a solution, which was then slowly
dripped into the first mentioned solution by means of a dropping
funnel provided with a pressure balance tube and stirred for 4
hours. Then, the resultant solution was further stirred at room
temperature to obtain a desired polyamic acid.
[0150] Then, the inherent viscosity of a 0.5 wt % solution of each
of these polyamic acids in N,N-dimethylacetamide was measured at a
temperature of 30.degree. C., the results being shown in Table
1.
1 TABLE 1 PAA1 PAA2 PAA3 PAA4 PAA5 PAA6 PAA7 PAA8 BNTA 1.00 -- --
1.00 -- -- -- -- ODPA -- 1.00 -- -- -- 1.00 -- -- 6FPA -- -- 1.00
-- 1.00 -- 1.00 -- PMA -- -- -- -- -- -- -- 1.00 ODA 0.95 0.95 0.95
-- -- -- 0.75 0.95 SNDA -- -- -- 0.95 0.95 -- -- -- 6FDA -- -- --
-- -- 0.95 0.20 -- TSDA 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
Solvent DMAC DMAC DMAC DMAC DMAC DMAC DMAC DMAC Concentration 20.18
20.42 20.35 19.55 20.63 19.24 20.65 18.20 wt % Inherent 0.98 0.82
0.68 0.92 0.60 0.94 0.66 1.10 viscosity *) [dL/g] *) 0.5 wt % DMAC
solution, Measuring temperature: 30.degree. C.
[0151] The tetracarboxylic dianhydride compounds, diamine compounds
and the solvent employed and shown in abbreviation in Table 1 are
as follows.
[0152] (Tetracarboxylic dianhydride compound)
[0153] BNTA: 3,3',4,4'-benzophenonetetracarboxylic dianhydride.
[0154] ODPA: oxy-4,4'-diphtalic dianhydride.
[0155] 6FPA: 1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-diphthalic
dianhydride.
[0156] PMA: Pyromellitic dianhydride.
[0157] (Diamine compound)
[0158] ODA: Oxy-4,4'-dianiline.
[0159] SNDA: Sulfonyl-3,3'-dianiline.
[0160] 6FDA:
1,1,1,3,3,3-hexafluoro-2,2-propylidene-4,4'-dianiline.
[0161] TSDA:
1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane.
[0162] (Solvent)
[0163] DMAC: N,N-dimethylacetamide.
[0164] (2) Preparation of photosensitive polyimide solution of
positive type:
[0165] The photosensitive dissolution inhibitor shown in Table 2
was added to the synthesized polyamic acid solution shown in Table
1 at a predetermined mixing ratio denoted by % by weight based on
the polyamic acid. The mixed system was stirred at room temperature
with a mixing rotor until the mixture was made uniform. Then, the
resultant mixture was filtered by a membrane filter having pores
sized at 0.2 .mu.m so as to obtain a desired photosensitive
polyimide solution of a positive type.
2TABLE 2 Photo- Photo- Photo- Polyamic sensitive Addition Photo-
Polyamic sensitive Addition sensitive acid dissolution amount
sensitive acid dissolution amount poyimide solution inhibitor (wt
%) poyimide solution inhibitor (wt %) PPI1 PAA1 PS-1 20.0 PPI11
PAA4 PS-2 20.0 PPI2 PAA2 PS-1 20.0 PPI12 PAA7 PS-2 20.0 PPI3 PAA3
PS-1 20.0 PPI13 PAA3 PS-3 20.0 PPI4 PAA4 PS-1 20.0 PPI14 PAA4 PS-3
20.0 PPI5 PAA5 PS-1 20.0 PPI15 PAA7 PS-3 20.0 PPI6 PAA6 PS-1 20.0
PPI16 PAA3 PS-4 20.0 PPI7 PAA7 PS-1 20.0 PPI17 PAA4 PS-4 20.0 PPI8
PAA1 PS-2 20.0 PPI18 PAA7 PS-4 20.0 PPI9 PAA2 PS-2 20.0 PPI19 PAA3
PS-5 20.0 PPI10 PAA3 PS-2 20.0 PPI20 PAA7 PS-5 20.0 *)wt % based on
polyamic acid
[0166] The abbreviations of the photosensitive dissolution
inhibitors shown in Table 2 represent the compounds given
below:
[0167] PS-1: reaction compound between tris(4-hydroxyphenyl)methane
and NAC5 (1,2-naphthoquinone-2-diazide-5-sulfonylchloride (average
introduction rate of naphthoquinone diazide sulfonyl group relative
to the phenolic OH group: 70 mol %);
[0168] PS-2: reaction compound between
1,1-bis(4-hydroxyphenyl)-1-{4-[2-(4- -hydrozyphenyl)-2-propyl]
phenyl}ethane and NAC5 (average introduction rate of naphthoquinone
diazide sulfonyl group relative to the phenolic OH group: 70 mol
%);
[0169] PS-3: reaction compound between
1,1,1,3,3,3-hexafluoro-2,2-propylid- ene-4,4-diphenol and NAC5
(average introduction rate of naphthoquinone diazide sulfonyl group
relative to the phenolic OH group: 100 mol %);
[0170] PS-4: reaction compound between
3,3-bis(4-hydroxyphenyl)phthalide and NAC5 (average introduction
rate of naphthoquinone diazide sulfonyl group relative to the
phenolic OH group: 100 mol %);
[0171] PS-5: reaction compound between oxy-4,4'-dianiline and NAC5
(average introduction rate of naphthoquinone diazide sulfonyl group
relative to NH.sub.2 group: 100 mol %).
[0172] (3) Preparation of developing solution:
[0173] The basic compounds shown in Table 3 were dissolved in and
diluted by an ion exchange water to a predetermined concentration
(denoted by concentration by weight and molar concentration),
followed by filtering the resultant diluted solution with a
membrane filter having pores of 0.2 .mu.m so as to obtain desired
aqueous solutions of the developing solution (DEV-1 to DEV-15). For
comparison, aqueous solutions of basic compounds [weakly basic
amines (WAM-1 to WAM-3), strongly basic amines (SAM-1 to SAM-9) and
inorganic alkaline salts (ALK-1 to ALK-3)], which fails to fall
within the scope of the present invention, were also prepared by
the similar method.
3TABLE 3 Base Weight Molar Develop- dissocia- concentra- concentra-
ing tion index tion tion solution Basic compound pkb*) (wt %)
(mol/L) pH(20.degree. C.) DEV-1 N-methyl imidazole 6.87 1.64 0.200
10.39 DEV-2 N-methyl morpholine 6.59 2.02 0.200 10.49 DEV-3
5-methyl-3,4-dihydro-2H-pyrrole 6.09 1.66 0.200 10.77
[2-methyl-1-pyroline] DEV-4 2-(dimethyl amino) propionitrile 6.35
1.96 0.200 10.59 DEV-5 triethanol amine 6.24 2.98 0.200 10.72 DEV-6
N-methly diethanol amine 5.48 2.38 0.200 11.11 DEV-7 N-ethyl
imidazole 6.67 1.92 0.200 10.42 DEV-8 N-methyl imidazole 6.87 2.00
0.244 10.43 DEV-9 N-methyl morpholine 6.59 2.00 0.198 10.48 DEV-10
triethanol amine 6.24 2.00 0.134 10.61 DEV-11 N-methyl diethanol
amine 5.48 2.00 0.168 11.06 DEV-12 N-methyl imidazole 6.87 3.00
0.366 10.46 DEV-13 N-methyl morpholine 6.59 3.00 0.297 10.52 DEV-14
triethanol amine 6.24 3.00 0.201 10.72 DEV-15 N-methyl diethanol
amine 5.48 3.00 0.252 11.16 WAM-1 N,N-dimethyl aniline 8.88 2.42
0.200 9.25 WAM-2 pyridine 8.83 1.58 0.200 9.30 WAM-3 N-methyl
benzoimidazole 8.43 2.64 0.200 9.50 SAM-1 2-amino ethanol 4.50 1.22
0.200 11.67 SAM-2 2-(diethylamino) ethanol 3.90 2.34 0.200 11.82
SAM-3 triethyl amine 3.29 2.02 0.200 12.29 SAM-4 piperidine 2.87
1.70 0.200 12.43 SAM-5 tetramethyl amnionium hydroxide <0 1.82
0.200 13.45 SAM-6 tetramethyl ammonium hydroxide <0 0.40 0.044
12.89 SAM-7 tetramethyl ammonium hydroxide <0 0.20 0.022 12.60
SAM-8 2-amino ethanol 4.50 0.50 0.082 11.36 SAM-9 2-(diethylamino)
ethanol 3.90 0.70 0.060 11.63 ALK-1 potassium carbonate 3.69 1.38
0.100 11.80 ALK-2 sodium hydroxide <0 0.80 0.200 13.41 ALK-3
sodium hydroxide <0 0.20 0.050 12.92 *)Value of aqueous solution
at 25.degree. C. [pKb = 14 - pKa (acid dissociation index of
portion complex)]
[0174] (4) Evaluation of residual film characteristics:
[0175] A silicon wafer having a diameter of 4 inches was coated by
a spin coating method with the photosensitive polyimide solution
(PPI1), followed by heating the coating on a hot plate set at
100.degree. C. for 3 minutes (pre-baking) to form a resin layer
having a thickness of about 5 .mu.m. The initial film thickness was
measured by a Taly Step (Taylor-Hobson Model). Then, the surface of
the resin layer was selectively exposed to light by using a light
exposure apparatus PLA-501FA manufactured by Cannon Corporation
with a quartz mask for evaluating the residual film characteristics
disposed on the resin layer.
[0176] After the light exposure step, the silicon wafer was dipped
for 30 seconds (or 60 seconds) in the developing solution shown in
Table 4, followed by applying a water wash for 20 seconds. Finally,
the resin layer was dried with a nitrogen air gun so as to prepare
a polyimide precursor pattern film (Examples 1-7 and Comparative
Examples 1 to 15).
[0177] A cross section of the pattern film was cut and peeled off
with a razor, followed by measuring the film thickness in the
light-exposed portion and the non-exposed portion with a Taly Step.
The residual film characteristics were determined by comparison of
the film thickness thus measured with the initial film thickness.
Table 4 shows the results.
4 TABLE 4 Residual Residual film film rate in rate in Light light-
non- Photo- Film irridation exposed exposed sensitive thickness
amount Developing Developing portion portion polyimide (.mu.m)
(mJ/cm.sup.2) solution time (sec) (%) (%) Example 1 PPI1 5.0 300
DEV-1 30 0 96 Example 2 PPI1 5.0 300 DEV-2 30 0 95 Example 3 PPI1
5.0 300 DEV-3 30 0 95 Example 4 PPI1 5.0 300 DEV-4 30 0 95 Example
5 PPI1 5.0 300 DEV-5 30 0 88 Example 6 PPI1 5.0 300 DEV-6 30 0 82
Example 7 PPI1 5.0 300 DEV-7 30 0 96 Comparative PPI1 5.0 300 WAM-1
30 100 100 Example 1 Comparative PPI1 5.0 300 WAM-2 30 100 100
Example 2 Comparative PPI1 5.0 300 WAM-3 30 100 100 Example 3
Comparative PPI1 5.0 300 SAM-1 30 0 38 Example 4 Comparative PPI1
5.0 300 SAM-2 30 0 12 Example 5 Comparative PPI1 5.0 300 SAM-3 30 0
0 Example 6 Comparative PPI1 5.0 300 SAM-4 30 0 0 Example 7
Comparative PPI1 5.0 300 SAM-5 30 0 0 Example 8 Comparative PPI1
5.0 300 SAM-6 60 0 42 Example 9 Comparative PPI1 5.0 300 SAM-7 60 5
55 Example 10 Comparative PPI1 5.0 300 SAM-8 60 0 56 Example 11
Comparative PPI1 5.0 300 SAM-9 60 0 48 Example 12 Comparative PPI1
5.0 300 ALK-1 30 0 0 Example 13 Comparative PPI1 5.0 300 ALK-2 30 0
0 Example 14 Comparative PPI1 5.0 300 ALK-3 60 0 40 Example 15
[0178] Table 4 supports the excellent effects of the present
invention, as apparent from the comparison based on the same
concentration (0.2 mol/L (liter)) of the developing solution.
Specifically, in the case of using the developing solution of the
present invention, the residual film is 0 in the light-exposed
portion and the residual film in the non-exposed portion is 82 to
96% in the non-exposed portion (Examples 1 to 7), supporting good
residual film characteristics. However, in the case of using the
developing solution using an amine compound, which was weakly basic
(pKb>8) compared with the amine compound specified in the
present invention, any of the light-exposed portion and the
non-exposed portion was not dissolved, failing to form a pattern
(Comparative Examples 1 to 3). Also, in the case of using the
developing solution using an amine compound, which was strongly
basic (pKb<5) compared with the amine compound specified in the
present invention, and an inorganic alkali salt, the residual film
rate in the non-exposed portion is 0 to 38%, supporting very poor
residual film characteristics (Comparative Examples 4-8, 13 and
14). Further, in the case of using the developing solution using an
amine compound, which was strongly basic (pKb<5) compared with
the amine compound specified in the present invention, and an
inorganic alkali salt, said developing solution being diluted with
a diluent about 10 times as much as the developing solution, it is
certainly possible to form a pattern if the developing time is
prolonged to 60 seconds. However, the residual film characteristics
remained to be as high as 40 to 56% (Comparative Examples 9, 11, 12
and 15).
[0179] The experimental data support that the developing solution
of the present invention permits markedly improving the residual
film characteristics of the positive photosensitive polyimide of
the type that a photosensitive dissolution inhibitor is added
thereto, making it possible to perform a pattern formation with a
high residual film rate.
[0180] (5) Evaluation of resolution characteristics:
[0181] First of all, a solution of each photosensitive resin
composition shown in Tables 5 to 8 was coated on the surface of a
silicon wafer 4 inches in diameter by means of a spin-coating
method, and then the coated layer was heated (pre-baking) for 3
minutes on a hot plate heated up to 100.degree. C. thereby to form
a resin layer having a film thickness of about 5 .mu.m. The initial
film thickness was measured by a Taly Step. Then, the resin layer
was exposed through a quartz mask for resolution test to the
irradiation of light at a predetermined exposure dose by using a
light exposure apparatus (PLA-501FA, Canon Co., Ltd.).
[0182] Then, the silicon wafer was dipped in each developing
solution shown in Tables 5 to 8 for 40 to 120 seconds, followed by
water wash for 20 seconds. Finally, the resin layer was dried with
a nitrogen air gun to form a polyimide precursor pattern film
(Examples 8 to 66 and Comparative Examples 16 to 69).
[0183] The film thickness in the light-exposed portion and the
non-exposed portion was measured by a Taly Step. Further, a cross
section of the formed pattern film was observed with an electron
microscope (SEM). The results of the characteristic test are shown
in Tables 5 to 8.
5 TABLE 5 Residual film Resolution rate in Photo- Film character-
non-exposed sensitive thickness Sensitivity Developing Developing
istics portion polyimide (.mu.m) (mJ/cm.sup.2) solution time (sec)
(.mu.m) (%) Example 8 PPI1 5.0 180 DEV-8 60 5.0 96 Example 9 PPI1
5.0 180 DEV-9 60 5.5 95 Example 10 PPI1 5.0 180 DEV-10 60 7.0 88
Example 11 PPI1 5.0 180 DEV-11 60 8.0 82 Example 12 PPI2 5.0 160
DEV-8 60 5.0 95 Example 13 PPI2 5.0 160 DEV-9 60 5.5 95 Example 14
PPI2 5.0 160 DEV-10 60 7.0 86 Example 15 PPI2 5.0 160 DEV-11 60 8.0
80 Example 16 PPI3 4.8 140 DEV-12 40 4.0 96 Example 17 PPI3 4.8 140
DEV-13 40 4.5 96 Example 18 PPI3 4.8 140 DEV-14 40 5.0 89 Example
19 PPI3 4.8 140 DEV-15 40 6.0 83 Example 20 PPI4 5.1 160 DEV-8 60
4.5 95 Example 21 PPI4 5.1 160 DEV-9 60 5.0 95 Example 22 PPI4 5.1
160 DEV-10 60 6.0 85 Example 23 PPI4 5.1 160 DEV-11 60 8.0 80
Example 24 PPI5 4.8 140 DEV-12 40 4.0 97 Example 25 PPI5 4.8 140
DEV-13 40 4.5 95 Example 26 PPI5 4.8 140 DEV-14 40 5.0 88 Example
27 PPI5 4.8 140 DEV-15 40 6.0 81 Example 28 PPI6 5.2 160 DEV-12 40
5.0 96 Example 29 PPI6 5.2 160 DEV-13 40 5.5 96 Example 30 PPI6 5.2
160 DEV-14 40 7.0 89 Example 31 PPI6 5.2 160 DEV-15 40 8.0 83
Example 32 PPI7 4.9 140 DEV-12 60 4.0 95 Example 33 PPI7 4.9 140
DEV-13 60 4.5 95 Example 34 PPI7 4.9 140 DEV-14 60 5.0 88 Example
35 PPI7 4.9 140 DEV-15 60 6.0 82 Example 36 PPI8 5.0 180 DEV-8 60
5.0 96 Example 37 PPI8 5.0 180 DEV-9 60 5.5 95 Example 38 PPI8 5.0
180 DEV-10 60 7.0 88
[0184]
6 TABLE 6 Photo- Film Resolution Residual sensitive thickness
Sensitivity Developing Developing characteristics film rate in
polyimide (.mu.m) (mJ/cm.sup.2) solution time (sec) (.mu.m)
nonexposed portion (%) Example 39 PPI9 5.0 160 DEV-8 60 5.0 95
Example 40 PPI9 5.0 160 DEV-9 60 5.5 95 Example 41 PPI9 5.0 160
DEV-10 60 7.0 87 Example 42 PPI10 4.8 140 DEV-12 40 4.0 95 Example
43 PPI10 4.8 140 DEV-13 40 4.5 95 Example 44 PPI10 4.8 140 DEV-14
40 5.0 85 Example 45 PPI11 5.1 160 DEV-8 60 4.5 96 Example 46 PPI11
5.1 160 DEV-9 60 5.0 95 Example 47 PPI11 5.1 160 DEV-10 60 6.0 88
Example 48 PPI12 4.9 140 DEV-12 40 4.0 95 Example 49 PPI12 4.9 140
DEV-13 40 4.5 95 Example 50 PPI12 4.9 140 DEV-14 40 5.0 86 Example
51 PPI13 4.8 140 DEV-12 40 4.5 94 Example 52 PPI13 4.8 140 DEV-13
40 5.0 94 Example 53 PPI14 5.1 160 DEV-8 60 5.0 92 Example 54 PPI14
5.1 160 DEV-9 60 6.0 92 Example 55 PPI15 4.9 140 DEV-12 60 4.5 95
Example 56 PPI15 4.9 140 DEV-13 60 5.0 94 Example 57 PPI16 4.8 140
DEV-12 40 4.5 95 Example 58 PPI16 4.8 140 DEV-13 40 5.0 94 Example
59 PPI17 5.1 160 DEV-8 60 5.0 92 Example 60 PPI17 5.1 160 DEV-9 60
6.0 91 Example 61 PPI18 4.9 140 DEV-12 60 4.5 94 Example 62 PPI18
4.9 140 DEV-13 60 5.0 94 Example 63 PPI19 4.8 140 DEV-12 40 4.0 95
Example 64 PPI19 4.8 140 DEV-13 40 4.5 95 Example 65 PPI20 4.9 140
DEV-12 60 4.0 96 Example 66 PPI20 4.9 140 DEV-13 60 4.5 95
Comparative PPI1 5.0 180 SAM-6 60 >30 42 Example 16 Comparative
PPI1 5.0 180 SAM-8 60 25 56 Example 17 Comparative PPI1 5.0 180
SAM-9 60 >30 48 Example 18 Comparative PPI1 5.0 180 ALK-3 60
>30 40 Example 19 Comparative PPI2 5.0 160 SAM-6 60 >30 35
Example 20 Comparative PPI2 5.0 160 SAM-B 60 30 52 Example 21
[0185]
7 TABLE 7 Residual film rate in Resolution non- Photo- Film charac-
exposed sensitive thickness Sensitivity Developing Developing
teristics portion polyimide (.mu.m) (mJ/cm.sup.2) solution time
(sec) (.mu.m) (%) Comparative PPI2 5.0 160 SAM-9 60 >30 42
Example 22 Comparative PPPI2 5.0 160 ALK-3 60 >30 36 Example 23
Comparative PPI3 4.8 140 SAM-6 80 25 56 Example 24 Comparative PPI3
4.8 140 SAM-8 80 20 66 Example 25 Comparative PPI3 4.8 140 SAM-9 80
20 60 Example 26 Comparative PPI3 4.8 140 ALK-3 80 30 52 Example 27
Comparative PPI4 5.1 160 SAM-6 60 >30 44 Example 28 Comparative
PPI4 5.1 160 SAM-8 60 30 54 Example 29 Comparative PPI4 5.1 160
SAM-9 60 >30 50 Example 30 Comparative PPI4 5.1 160 ALK-3 60
>30 42 Example 31 Comparative PPI5 4.8 140 SAM-6 80 25 58
Example 32 Comparative PPI5 4.8 140 SAM-8 80 20 62 Example 33
Comparative PPI5 4.8 140 SAM-9 80 20 60 Example 34 Comparative PPI5
4.8 140 ALK-3 80 30 52 Example 35 Comparative PPI6 5.2 160 SAM-6 80
30 51 Example 36 Comparative PPI6 5.2 160 SAM-8 80 30 58 Example 37
Comparative PPI6 5.2 160 SAM-9 80 30 55 Example 38 Comparative PPI6
5.2 160 ALK-3 80 30 50 Example 39 Comparative PPI7 4.9 140 SAM-6
120 25 55 Example 40 Comparative PPI7 4.9 140 SAM-8 120 20 62
Example 41 Comparative PPI7 4.9 140 SAM-9 120 20 60 Example 42
Comparative PPI7 4.9 140 ALK-3 120 30 52 Example 43 Comparative
PPI8 5.0 180 SAM-6 60 >30 40 Example 44 Comparative PPI8 5.0 180
SAM-8 60 30 51 Example 45 Comparative PPI9 5.0 160 SAM-6 60 >30
33 Example 46 Comparative PPI9 5.0 160 SAM-8 60 30 50 Example 47
Comparative PPI10 4.8 140 SAM-6 80 30 55 Example 48 Comparative
PPI10 4.8 140 SAM-8 80 25 62 Example 49 Comparative PPI11 5.1 160
SAM-6 60 >30 40 Example 50 Comparative PPI11 5.1 160 SAM-8 60 30
52 Example 51 Comparative PPI12 4.9 140 SAM-6 80 30 50 Example 52
Comparative PPI12 4.9 140 SAM-8 80 30 57 Example 53 Comparative
PPI13 4.8 140 SAM-6 80 30 48 Example 54 Comparative PPI13 4.8 140
SAM-8 80 30 56 Example 55
[0186]
8 TABLE 8 Residual film Resolution rate in Photo- Film character-
non-exposed sensitive thickness Sensitivity Developing Developing
istics portion polyimide (.mu.m) (mJ/cm.sup.2) solution time (sec)
(.mu.m) (%) Comparative PPI14 5.1 160 SAM-6 60 >30 38 Example 56
Comparative PPI14 5.1 160 SAM-8 60 30 49 Example 57 Comparative
PPI15 4.9 140 SAM-6 80 30 50 Example 58 Comparative PPI15 4.9 140
SAM-8 80 30 55 Example 59 Comparative PPI16 4.8 140 SAM-6 80 30 50
Example 60 Comparative PPI16 4.8 140 SAM-8 80 30 57 Example 61
Comparative PPI17 5.1 160 SAM-6 60 >30 41 Example 62 Comparative
PPI17 5.1 160 SAM-8 60 30 50 Example 63 Comparative PPI18 4.9 140
SAM-6 80 30 52 Example 64 Comparative PPI18 4.9 140 SAM-8 80 30 57
Example 65 Comparative PPI19 4.8 140 SAM-6 80 30 56 Example 66
Comparative PPI19 4.8 140 SAM-8 80 25 60 Example 67 Comparative
PPI20 4.9 140 SAM-6 80 30 61 Example 68 Comparative PPI20 4.9 140
SAM-8 80 25 65 Example 69
[0187] In the case of using the developing solution of the present
invention (Examples 8 to 66), it was possible to form a fine
positive pattern having a line and space of 4.0 to 8.0 .mu.m with a
high residual film rate of 80 to 97%. In the case of using an amine
compound having a strong basicity (pKb<5), compared with the
amine compound specified in the present invention, and an inorganic
alkali salt, the residual film rate was 33 to 66%, and the
resolution characteristics were not lower than 20 .mu.m, resulting
in failure to form a fine pattern, as shown in Comparative Examples
16 to 69.
[0188] As apparent from the experimental data, the developing
solution of the present invention permits markedly improving the
residual film characteristics of the positive photosensitive
polyimide of the type that a photosensitive dissolution inhibitor
is added thereto, making it possible to perform a pattern formation
with a high residual film rate.
[0189] (6) Trial manufacture of an electronic part:
[0190] Various electronic parts shown in FIGS. 1 to 4 were
manufactured on the trial basis by using the polyimide film pattern
forming method of the present invention.
[0191] FIG. 1 illustrates a cross-sectional view of a semiconductor
device provided with a passivation film consisting of a polyimide
pattern which was formed by using a pattern forming method of the
present invention. In this case, the photosensitive polyimide
material of Example PPI5 was employed for forming a patterned
polyimide film to be utilized as a passivation film as explained
below.
[0192] First of all, the photosensitive polyimide material was
coated on the surface of a silicon substrate (wafer) bearing
thereon a PNP type transistor on which a thermal oxide film and
electrodes were formed. The coated layer was pre-baked for 10
minutes at a temperature of 100.degree. C. to obtain a resin layer
having a film thickness of about 8 .mu.m. Subsequently, the resin
layer was exposed through a quartz mask to the irradiation of light
at a dosage of 300 mJ/cm.sup.2 by using a light exposure apparatus
(PLA-501FA, Canon Co.).
[0193] After this light exposure, the silicon substrate was dipped
in the developing solution of the present invention (aqueous
solution of 3 wt % N-methyl imidazole) for 60 seconds thereby
allowing the exposed portions of the resin layer to be selectively
dissolved and removed. Thereafter, the resin layer was rinsed with
water for 20 seconds. Finally, the resin layer was dried with a
nitrogen air gun, followed by heating the pattern thus obtained at
150.degree. C. for 60 minutes, at 250.degree. C. for 60 minutes,
and at 350.degree. C. for 60 minutes in a program oven, thereby
obtaining a polyimide film pattern.
[0194] Referring to FIG. 1, a bonding pad 12 is formed on an LSI
chip 11 mounted on a tab 13, and a passivation film 14 consisting
of a patterned polyimide film is superimposed thereon. The bonding
pad 12 formed on the LSI chip 11 is connected via a bonding wire 15
to a lead frame 16. Furthermore, these members are entirely
encapsulated with a sealing agent 17.
[0195] When a passivation film 14 consisting of a patterned
polyimide film formed by a pattern forming method of the present
invention is employed in the manufacture of a semiconductor
element, it is possible to obtain a semiconductor element which is
excellent in reliability while substantially preventing any
defective product from being produced in the manufacturing steps.
Moreover, since the conventional PEP step can be dispensed with,
the manufacturing process would be simplified without giving rise
to any problem involving safety, etc.
[0196] FIG. 2 illustrates a cross-sectional view showing a portion
of a multi-chip module provided with an interlayer insulation film
which was formed using a pattern forming method of the present
invention. In this case, a polyimide film which was formed by using
the photosensitive polyimide material PPI3 and patterned in the
same manner as mentioned above was utilized as the interlayer
insulation film.
[0197] Referring to FIG. 2, a thermal oxide film 22 is formed on
the surface of a silicon substrate (wafer) 21. On this thermal
oxide film 22, a copper wiring 23, an interlayer insulation film 24
consisting of a polyimide film, another copper wiring 25 and
another interlayer insulation film 26 consisting of a polyimide
film are successively superimposed. Furthermore, a contact hole is
formed at a portion of the upper interlayer insulation film 26. A
Pb/Sn electrode 27 connected to the copper wiring 23 and BLM (Ball
Limiting Metallization) 28 are also formed.
[0198] Since the interlayer insulation films 24 and 26 are formed
through a curing of a spin-coated layer of a solution comprising a
photosensitive polyimide, the step portions to be formed due to the
presence of the copper wiring can be greatly minimized, thus making
it possible to flatten the surface of the device and to obtain a
highly reliable wiring structure.
[0199] FIG. 3 illustrates a cross-sectional view showing an
embedded optical waveguide provided with a core layer consisting of
a polyimide film which was formed using a pattern forming method of
the present invention. In this case, a polyimide film which was
formed by using the photosensitive polyimide material of PPI7 and
patterned in the same manner as mentioned above was utilized as a
polymer core layer.
[0200] Referring to FIG. 3, a lower clad layer 32 consisting of a
heat-cured PAA8 film is formed on the surface of a silicon
substrate (wafer) 31. On this lower clad layer 32, a core polymer
layer 33 and an upper clad layer 34 consisting of a heat-cured PAA8
film are successively superimposed.
[0201] Since the core polymer layer 33 can be formed easily and
precisely by using a polyimide pattern forming method of the
present invention, the conventional PEP step can be dispensed with,
so that the productivity of the device can be greatly improved.
[0202] FIG. 4 illustrates a cross-sectional view showing a
semiconductor element having a multilayered wiring structure
provided with an interlayer insulation film consisting of a
polyimide film pattern which was formed using a pattern forming
method of the present invention. In this case, a polyimide film
which was formed by using the photosensitive polyimide material in
Example PPI3 and patterned in the same manner as mentioned above
was utilized as the interlayer insulation film.
[0203] Referring to FIG. 4, a thermal oxide film 42 is formed on
the surface of a silicon substrate (wafer) 41 bearing thereon an
element region 47. A contact hole is formed at a portion of this
thermal oxide film 42, and a first Al wiring 43 is formed over the
contact hole. An interlayer insulation film 44 consisting of a
polyimide film is superimposed on this first Al wiring 43.
Furthermore, another contact hole is formed at a portion of the
interlayer insulation film 44, and a second Al wiring 45 connected
to the first Al wiring 43 is formed over the latter contact hole.
Further superimposed on this second Al wiring 45 is another
interlayer insulation film 46 made of a polyimide film.
[0204] Since the interlayer insulation film 44 is formed through a
curing of a spin-coated layer of a solution comprising a
photosensitive polyimide, the step portions to be formed on the
surface of substrate can be greatly minimized, thus making it
possible to form multi-layered Al wirings while maintaining the
flatness of the surface of the device and to obtain a highly
reliable wiring structure.
[0205] As described above in detail, the developing solution of the
present invention for a photosensitive polyimide makes it possible
to markedly improve the resolution characteristics and the residual
film characteristics of the photosensitive polyimide of the type
that a photosensitive dissolution inhibitor is added thereto. As a
result, use of the developing solution of the present invention for
a photosensitive polyimide in the developing step of the
photosensitive polyimide produces a prominent effect that a
polyimide film pattern of a high resolution can be formed with a
high residual film rate.
[0206] Further, it is also possible to provide a highly reliable
electronic parts wherein a polyimide film pattern excellent in
resolution, adhesion and heat resistance is utilized as an
insulating member, a protecting film member, a liquid crystal
member or an optical waveguide member by forming a polyimide film
pattern on a substrate surface by the polyimide film pattern
forming method of the present invention.
[0207] Therefore, the patterned polyimide film of the present
invention can be used as a wiring insulating film for an LSI, as a
humidity resistant protecting film for an LSI, as an a-ray
shielding film for an LSI, as a passivation film for a
semiconductor device, as a wiring insulating film for a multi-chip
module, as a wiring insulating film for a thin film magnetic head,
as a wiring insulating film for a magnetic bubble memory, or as an
optical material for forming an optical waveguide of an optical
device or as an orienting film of a liquid crystal display
device.
[0208] Further, the electronic part of the present invention
comprises a polyimide film excellent in resolution, heat
resistance, and adhesivity, which is formed on the surface of an
element such as a silicon substrate or a glass substrate, said
polyimide film acting as an insulating member, a protective film
member, a member of a liquid crystal element or a member of an
optical device. It follows that the electronic part of the present
invention is excellent in reliability.
[0209] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *