U.S. patent application number 11/516612 was filed with the patent office on 2007-02-15 for laminate, a substrate with wiring, an organic el display element, a connection terminal for an organic el display element and a method for producing each.
This patent application is currently assigned to ASAHI GLASS COMPANY, LIMITED. Invention is credited to Yasuhiko Akao, Teruo Fujiwara, Takehiko Hiruma, Nobuhiro Nakamura.
Application Number | 20070036955 11/516612 |
Document ID | / |
Family ID | 32211551 |
Filed Date | 2007-02-15 |
United States Patent
Application |
20070036955 |
Kind Code |
A1 |
Hiruma; Takehiko ; et
al. |
February 15, 2007 |
Laminate, a substrate with wiring, an organic EL display element, a
connection terminal for an organic EL display element and a method
for producing each
Abstract
A laminate for forming a substrate with wires, comprising a
conductive layer containing Al or an Al alloy as the major
component, formed on a substrate and a capping layer containing a
Ni--Mo alloy as the major component, formed on the conductive
layer, a substrate with wires produced by etching the laminate to
remove an unnecessary metal, and a method for producing the
same.
Inventors: |
Hiruma; Takehiko; (Yonezawa,
JP) ; Akao; Yasuhiko; (Higashiokitama, JP) ;
Fujiwara; Teruo; (Yonezawa, JP) ; Nakamura;
Nobuhiro; (Yokohama, JP) |
Correspondence
Address: |
C. IRVIN MCCLELLAND;OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
ASAHI GLASS COMPANY,
LIMITED
Tokyo
JP
100-8405
|
Family ID: |
32211551 |
Appl. No.: |
11/516612 |
Filed: |
September 7, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10682719 |
Oct 10, 2003 |
|
|
|
11516612 |
Sep 7, 2006 |
|
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Current U.S.
Class: |
428/209 |
Current CPC
Class: |
H01L 51/0017 20130101;
H01L 27/3288 20130101; H01L 51/0021 20130101; H01L 51/56 20130101;
Y10T 428/24917 20150115; Y10S 428/917 20130101 |
Class at
Publication: |
428/209 |
International
Class: |
B32B 3/00 20060101
B32B003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 17, 2002 |
JP |
2002-303278 |
Claims
1. A laminate comprising: a substrate, a first conductive layer
that comprises Al or an Al alloy as the major component present on
said substrate; and a capping layer that comprises a Ni--Mo alloy
as the major component present on said first conductive layer.
2. The laminate according to claim 1, wherein said Al alloy is an
alloy of Al and at least one metal selected from the group
consisting of Nd, Ag, and Cu.
3. The laminate according to claim 1, wherein the film thickness of
the conductive layer is 100 to 500 nm.
4. The laminate according to claim 2, wherein the film thickness of
the capping layer is 10 to 200 nm.
5-9. (canceled)
10. The laminate according to claim 1, wherein the capping layer
comprises at least one member selected from the group consisting of
(1) oxygen, (2) nitrogen, (3) oxygen and nitrogen, (4) oxygen and
carbon, and (5) oxygen, nitrogen, and carbon.
11. The laminate according to claim 1, wherein the capping layer
comprises Ni by 20-90 mass % based on all the components, and
wherein the capping layer comprises Mo by 10-80 mass % based on all
the components.
12. An organic EL display element comprising a laminate described
in claim 1, wherein a second electrode layer is present between the
substrate and a first electrode layer, wherein an organic EL layer
is disposed between the first electrode layer and the second
electrode layer, and wherein the substrate, the first conductive
layer, and the capping layer are arranged in an order starting from
the substrate.
13. An organic EL display element comprising: a first electrode
layer; and a second electrode layer present between the first
electrode layer and a substrate; and an organic EL layer disposed
between the first electrode layer and the second electrode layer,
wherein a first conductive layer is connected electrically to the
first electrode layer, wherein a capping layer is present on an
upper side of the first conductive layer, wherein the first
conductive layer comprises Al or an Al alloy as the major
component, and wherein the capping layer comprises a Ni--Mo alloy
as the major component.
14. The organic EL display element according to claim 13, wherein
the capping layer comprises at least one member selected from the
group consisting of (1) oxygen, (2) nitrogen, (3) oxygen and
nitrogen, (4) oxygen and carbon, and (5) oxygen, nitrogen, and
carbon.
15. The organic EL display element according to claim 13, further
comprising an ITO layer on said surface and an underlayer present
on said ITO layer.
16. The organic EL display element according to claim 15, wherein
the anti-Ni-diffusion layer comprises MoNb, MoTa, MoV, or MoW.
17. The organic EL display element according to claim 15, further
comprising an underlayer that comprises Mo or a Mo alloy present
under the first conductive layer.
18. The organic EL display element according to claim 13, wherein
the second electrode layer is an ITO layer.
19. A connection terminal for an organic EL display element, to
connect a first electrode layer present on the substrate for the
organic EL display element to a driving circuit, the connection
terminal comprising: a first conductive layer that comprises Al or
an Al alloy as the major component; a capping layer that comprises
a Ni--Mo alloy as the major component, wherein said capping layer
is present at an upper side of the first conductive layer, and
wherein a circuit supplies an electric current from the driving
circuit to the first electrode layer.
20. The connection terminal for an organic EL display element
according to claim 19, wherein the capping layer comprises at least
one member selected from the group consisting of (1) oxygen, (2)
nitrogen, (3) oxygen and nitrogen, (4) oxygen and carbon, and (5)
oxygen, nitrogen, and carbon.
21. The connection terminal for an organic EL display element
according to claim 19, further comprising an ITO layer on said
surface and an underlayer present on said ITO layer.
22. The connection terminal for an organic EL display element
according to claim 19, wherein the circuit supplies an electric
current from a plurality of second electrodes to a single first
electrode, and the maximum instantaneous current flowing into the
single first electrode is at least 50 mA.
23-25. (canceled)
26. A substrate comprising: the laminate described in claim 1, and
wires, wherein the laminate is patterned in a flat form.
27-29. (canceled)
30. An organic EL display element comprising: the organic EL
display element described in claim 13; and a driving circuit
connected to the display element so that a display has a luminance
of at least 100 cd/m.sup.2.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The entire disclosure of Japanese Patent Application No.
2002-303278 filed on Oct. 17, 2002, including specification,
claims, drawings and summary are incorporated herein by reference
in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a laminate, a substrate
with wires, an organic EL display element, a connection terminal
for the organic EL display element and a method for producing
each.
[0004] 2. Discussion of Background
[0005] As a flat panel display element (FPD) for coming generation,
an organic EL display element has come into use for a cellular
phone or the like. The organic EL display element comprises an
organic luminescent material wherein a display takes place by its
self-luminescence. Accordingly, it is more advantageous than
conventional LCD or PDP in terms of quick response, visibility,
luminance and so on.
[0006] The basic structure and the principle of operation are
described in, for instance, "Appl. Phys. Lett., 51, 913 (1987). In
order to cause luminescence, it has opposing electrodes at least
one of which is a transparent electrode (made of, for instance, a
tin-doped indium oxide (ITO)) and organic layers such as a hole
transport layer, a light emission layer, an electron transport
layer and so on are provided in this order from an anode side,
between the opposing electrodes. Further research has been carried
out so as to prolong the lifetime of the organic EL display
element, to achieve an increased luminance, a full-colored display
and so on.
[0007] The organic EL display element belongs to a current-driving
type display. Particularly, in a passive-driving type organic EL
display element, a current is supplied to it in only a selection
period for each row, whereby the light emission layer emits light
in response to this so that a display takes place. As a result, a
large current flows into the electrodes unlike a case of using a
voltage-driving type LCD.
[0008] For example, it is assumed a case that a panel having a
pixel size of 300 .mu.m.times.300 .mu.m and 100 anodes is driven at
a duty ratio of 1/64. The total amount of the current flowing into
cathodes in a selection period is 172.8 mA in order to operate it
at a luminous efficiency of 1 cd/A and an average luminance of 300
cd/m.sup.2.
[0009] With demands of a full-colored display and a high definition
display in the flat panel display (FPD) in recent years, it is
desired for the transparent electrode to have a further low
resistance. However, reduction in the resistance of ITO used
conventionally for LCD or the like approaches the limit.
Accordingly, a low resistance wiring technique combining a metal
having a low resistance with ITO, used widely in TFT-LCD and so on,
has been introduced.
[0010] Thus, it is necessary to use the low resistance wiring
technique for controlling voltage increase due to a large current
between the cathode and the connection terminal in the organic EL
display element. Generally, a structure that supplementary wires
are provided between cathodes and connection terminals so that a
current flows to the connection terminals through the supplementary
wires, is adopted.
[0011] However, there are very strong demands to increase the size,
precision and luminance of the display panel. In order to achieve
these demands, it is necessary to reduce further resistances of the
supplementary wires. As a low resistance wiring material for FPD,
Al or an Al alloy is generally used. However, hillocks are apt to
occur in using Al or the Al alloy, and an Al oxide is easily
produced on its surface. Further, even when such material is
electrically connected to another metal, the contact resistance is
high and accordingly, it is difficult to use such material as it
is.
[0012] Therefore, a technique that Al or an Al alloy is capped with
Mo or a Mo alloy (an alloy of Mo and Cr, Ti, Ta, Zr, Hf or V) is
often adopted (see for example, JP-A-13-311954 as a prior art
document 1) because Mo can be etched with the same etching liquid
as for Al. Accordingly, when a combination of Mo and Al is used, Al
and Mo can be patterned together in a photolithographic process to
form a display panel.
[0013] However, since the humidity resistance of Mo is generally
low and it is easily corroded due to moisture in air, there was a
problem that when Mo was used as a wiring material for FPD, the
wire portions were apt to deteriorate. On the other hand, when Al
was capped with Cr having a high humidity resistance, it could not
be etched with the same etching liquid as for Al and therefore,
there was difficulty in patterning both materials together in a
manufacturing process.
[0014] Further, since Ni has a high humidity resistance, the
resistance does not show a substantial change even when it is left
under a high moisture condition. However, Ni can not actually be
etched when a certain kind of etching liquid (comprising phosphoric
acid: nitric acid: acetic acid and water=16:1:2:1 (in volume
ratio)) is used. ("Photoetching and Microfabrication" by Kiyotake
Naraoka and one other, published by Sogo Denshi Shuppansha (on May
10, 1977), p. 82-p. 83).
[0015] Further, since Ni is a ferromagnetic material, it is
difficult to use a magnetron sputtering method as a generally used
thin film forming method. Accordingly, it is difficult to use a
thin Ni film as a wiring material for FPD.
[0016] Further, in the organic EL display element, the contact
between a cathode and a supplementary wire and lowering of the
resistance of a connection terminal to a supplementary wire create
new problems. In particular, it is necessary for the contact
characteristics between the cathode and the supplementary wire to
have not only low resistance characteristics but also being stable
against the Joule heat generated at the contact portion depending
on the magnitude of an electric current flowing there.
[0017] Namely, the difficulty of increasing the contact resistance
by the Joule heat is required. The increase of the contact
resistance by the Joule heat is considered to be due to the
oxidation of the metal used for the supplementary wire or the
like.
[0018] FIG. 17 is a cross-sectional view partly omitted of an
organic EL display element prepared according to a conventional
technique. An anode 20a is formed on a transparent substrate 1 made
of glass or the like. An electrode disposed inside the element and
a driving circuit are connected with a supplementary wire 30X
comprising a connection-terminal-side pattern portion 30b and an
inner side pattern portion 30a. A cathode 70 is connected
electrically to a connecting wire 150 at an outer side by means of
the supplementary wire 30X. An organic EL layer 60 emits light by
supplying a current between the anode 20a and the cathode 70. A
counter substrate 80 is provided to seal the organic EL layer 60
and so on.
[0019] An insulation film 40 serves to define an opening region 40a
where the organic EL layer 60 and the anode 20a contact. In such
structure, generally, ITO (indium oxide-tin oxide) is used for the
anode 20a, and an easily oxidizable metal such as Al, Mg, Ag or the
like is used for the cathode. Metal such as Cr or the like is used
for the supplementary wire.
[0020] When a patterned Cr having a film thickness of 300 nm, a
width of 150 .mu.m, a length of 4 mm and a specific resistance of
20 .mu..OMEGA. cm is used for the supplementary wire, the
resistance is 17.7.OMEGA.. In this case, when the above-mentioned
current is supplied, a voltage drop of about 3.1 V takes place in
response to the resistance of the wire, whereby there is a voltage
increase beyond the predetermined electric potential.
[0021] Further, as shown in FIG. 17, an oxidized layer is formed on
the surface of the supplementary wire 30X with processes of
manufacturing, and accordingly, the contact resistance between the
cathode 70 and the supplementary wire 30X increases to thereby
increase a voltage in these members. The voltage rise is considered
to cause adverse effects such as an uneven display at the time of
gradation display and an increase in the breakdown of an anode
driver used.
[0022] Explanation will be made as to a supplementary wiring
technique described in JP-A-11-317292 (a prior art document 2). The
prior art document 2 is characterized in that a transparent
electrode material is used for a connection terminal connectable to
a driving circuit, and the same material is used for a cathode and
a supplementary wire. In this case, there would arise no problem
about the contact resistance between the cathode and the
supplementary wire unless surfaces of the cathode and the
supplementary wire are oxidized before the connection of the
cathode to the supplementary wire.
[0023] However, an easily oxidizable material is generally used for
the cathode of an organic EL display element. Therefore, when the
material for the supplementary wire is used also for the cathode,
there occurs a problem that the surface of supplementary wire is
oxidized during the manufacture of the organic EL display element
and the contact resistance to the cathode becomes high. In
particular, the increase of the contact resistance is remarkable
when it is kept at a high temperature. When Al or an Al alloy is
applied to the cathode or the supplementary wire, the contact
resistance increases remarkably when it is kept at about
100.degree. C.
[0024] JP-A-11-329750 (a prior art document 3) discloses a
technique of reducing the contact resistance between a cathode and
a supplementary wire. According to the proposal of the prior art
document 3, low-resistance contact characteristics can be obtained
by forming a supplementary wire portion into two portions: an
undercoat pattern and an electrode pattern, and TiN or Cr is used
for the undercoat pattern and Al is used for the electrode pattern
to bring the supplementary wire portion into contact with the
cathode.
[0025] In the prior art document 3, however, it is necessary to
conduct a photolithographic process twice in order to form the
supplementary wire portion. Further, in order to use TiN as a
material for wiring, it is necessary to apply dry etching for the
patterning which causes a problem of productivity. Further, in the
case of using Cr for the undercoat pattern, the contact resistance
may become extremely high when it is left at a high temperature of
about 100.degree. C. even though the initial contact
characteristics are excellent.
[0026] In the organic EL display element, a large current should be
supplied to the electrodes, and it is desirable to use a metal
having low resistance characteristics is used to connect the
cathode as described above. It is desirable that the connection
terminal has excellent weather resistance characteristics,
particularly, humidity resistance characteristics because it is not
disposed in the sealed element but it is exposed in the
environment.
[0027] Thus, when the material for the supplementary wire is used
for the organic EL display element, there is a requirement of not
only having excellent contact characteristics to the cathode but
also being capable of suppressing corrosion due to moisture as
possible because the material is extended from the sealed display
panel to the outside of it.
[0028] The present invention is to provide a laminate applicable to
an organic EL display element. It can form a substrate with wires
having excellent humidity resistance, and it provides also a low
resistance and an excellent patterning performance. Further, it is
an object of the present invention to provide a substrate with
wires formed by using the laminate.
[0029] In particular, the present invention is to provide a method
for producing a substrate with wires by forming a laminate suitable
for FPD such as an organic EL display element and etching the
laminate two dimensionally, and to provide a substrate with wire
formed by using the method.
[0030] Further, the present invention is to provide a circuit
structure exhibiting excellent low resistance characteristics at a
contact region constituting the circuit when a driving current is
supplied to an organic EL display element to cause light
emission.
[0031] Further, the present invention is to maintain low resistance
contact characteristics to the electrodes to which a large current
is supplied and to realize reliable contact characteristics.
Further, the present invention is to provide an organic EL display
element of high reliability wherein the corrosion resistance of a
metal constituting the electrodes and wires is improved.
SUMMARY OF THE INVENTION
[0032] According to an Embodiment 1 of the present invention, there
is provided a laminate for forming a substrate with wires, which
comprises a substrate, a first conductive layer containing Al or an
Al alloy as the major component, formed on the substrate, and a
capping layer containing a Ni--Mo alloy as the major component,
formed on the first conductive layer.
[0033] According to an Embodiment 2, there is provided the laminate
according to the Embodiment 1, wherein between the first conductive
layer and the substrate, an ITO layer and an underlayer are
arranged in this order from the side of the substrate.
[0034] According to an Embodiment 3, there is provided the laminate
according to the Embodiment 2, wherein the major component of the
underlayer is Mo or a Mo alloy.
[0035] According to an Embodiment 4, there is provided the laminate
according to the Embodiment 2 or 3, wherein the underlayer contains
NiMo as the major component and contains one member selected from
the group consisting of oxygen, nitrogen, oxygen and nitrogen,
oxygen and carbon, and oxygen, nitrogen and carbon.
[0036] According to an Embodiment 5, there is provided the laminate
according to the Embodiment 2, 3 or 4, wherein the content of Ni in
the underlayer is 20-90 mass % based on the all components and the
content of Mo is 10-80 mass % based on the all components.
[0037] According to an Embodiment 6, there is provided the laminate
according to the Embodiment 1, 2, 3, 4 or 5, wherein an
anti-Ni-diffusion layer without containing Ni is formed between the
first conductive layer and the capping layer.
[0038] According to an Embodiment 7, there is provided the laminate
according to the Embodiment 6, wherein the anti-Ni-diffusion layer
contains Mo as the major component and does not contain Ni.
[0039] According to an Embodiment 8, there is provided the laminate
according to the Embodiment 6 or 7, wherein the anti-Ni-diffusion
layer comprises MoNb, MoTa, MoV or MoW.
[0040] According to an Embodiment 9, there is provided the laminate
according to the Embodiment 6, 7 or 8, wherein the conductive
material in the anti-Ni-diffusion layer contains Mo, Nb or Ta, the
content of Mo is 80-98 mass % and the content of Nb or Ta is 2-20
mass %.
[0041] According to an Embodiment 10, there is provided the
laminate according to any one of Embodiments 1 to 9, wherein the
capping layer contains one member selected from the group
consisting of oxygen, nitrogen, oxygen and nitrogen, oxygen and
carbon, and oxygen, nitrogen and carbon.
[0042] According to an Embodiment 11, there is provided the
laminate according to any one of Embodiments 1 to 10, wherein the
content of Ni in the capping layer is 20-90 mass % based on the all
components and the content of Mo is 10-80 mass % based on the all
components.
[0043] According to an Embodiment 12, there is provided an organic
EL display element comprising a laminate described in any one of
Embodiments 1 to 11, wherein a second electrode layer is provided
on the substrate so as to face a first electrode layer, an organic
EL layer is disposed between the first electrode layer and the
second electrode layer, and the substrate, the first conductive
layer and the capping layer are arranged in this order from the
side of the substrate.
[0044] According to an Embodiment 13, there is provided an organic
EL display element comprising, a first electrode layer and a second
electrode layer facing the first electrode layer, formed on the
substrate, and an organic EL layer disposed between the first
electrode layer and the second electrode layer, wherein a first
conductive layer is connected electrically to the first electrode
layer, a capping layer is formed on an upper side of the first
conductive layer, the major component of the first conductive layer
is Al or an Al alloy, and the major component of the capping layer
is a Ni--Mo alloy.
[0045] According to an Embodiment 14, there is provided the organic
EL display element according to the Embodiment 13, wherein the
capping layer contains one member selected from the group
consisting of oxygen, nitrogen, oxygen and nitrogen, oxygen and
carbon, and oxygen, nitrogen and carbon.
[0046] According to an Embodiment 15, there is provided the organic
EL display element according to the Embodiment 13 or 14, wherein an
anti-Ni-diffusion layer without containing Ni is formed between the
first conductive layer and the capping layer.
[0047] According to an Embodiment 16, there is provided the organic
EL display element according to the Embodiment 13, 14 or 15,
wherein the anti-Ni-diffusion layer comprises MoNb, MoTa, MoV or
MoW.
[0048] According to an Embodiment 17, there is provided the organic
EL display element according to the Embodiment 13, 14, 15 or 16,
wherein an underlayer containing Mo or a Mo alloy is provided under
the first conductive layer.
[0049] According to an Embodiment 18, there is provided the organic
EL display element according to any one of Embodiments 13 to 17,
wherein the second electrode layer is an ITO layer.
[0050] According to an Embodiment 19, there is provided a
connection terminal for an organic EL display element, to connect a
first electrode layer provided on the substrate for the organic EL
display element to a driving circuit, the connection terminal
comprising a first conductive layer containing Al or an Al alloy as
the major component and a capping layer containing a Ni--Mo alloy
as the major component, which is formed at an upper side of the
first conductive layer, and a circuit to supply an electric current
from the driving circuit to the first electrode layer.
[0051] According to an Embodiment 20, there is provided the
connection terminal for an organic EL display element according to
the Embodiment 19, wherein the capping layer contains one member
selected from the group consisting of oxygen, nitrogen, oxygen and
nitrogen, oxygen and carbon, and oxygen, nitrogen and carbon.
[0052] According to an Embodiment 21, there is provided the
connection terminal for an organic EL display element according to
the Embodiment 19 or 20, wherein an anti-Ni-diffusion layer without
containing Ni is formed between the first conductive layer and the
capping layer.
[0053] According to an Embodiment 22, there is provided the
connection terminal for an organic EL display element according to
the Embodiment 19, 20 or 21, which has a circuit to supply an
electric current from a plurality of second electrodes to a single
first electrode, and the maximum instantaneous current flowing into
the single first electrode is at least 50 mA.
[0054] According to an Embodiment 23, there is provided a method
for producing the laminate described in any one of Embodiments 1 to
11, wherein the first conductive layer is formed on the substrate
and then, the capping layer is formed thereon.
[0055] According to an Embodiment 24, there is provided the method
for producing the laminate according to the Embodiment 23, wherein
a transparent second conductive layer is formed, the formed layer
is patterned and then, the first conductive layer is formed
thereon.
[0056] According to an Embodiment 25, there is provided the method
for producing the laminate according to the Embodiment 23 or 24,
wherein in the formation of the capping layer, a process of
oxidizing or nitriding, or processes of oxidizing and nitriding,
oxidizing and carbonizing, nitriding and carbonizing or oxidizing,
nitriding and carbonizing are carried out.
[0057] According to an Embodiment 26, there is provided a substrate
with wires, which comprises the laminate described in any one of
Embodiments 1 to 11 wherein the laminate is patterned in a flat
form.
[0058] According to an Embodiment 27, there is provided a method
for producing the connection terminal for an organic EL display
element, described in the Embodiment 19, 20, 21 or 22,
characterized in that a transparent second conductive layer is
formed; the formed layer is patterned; a lamination layer
comprising the first conductive layer and the capping layer is
formed, and then, the lamination layer is patterned.
[0059] According to an Embodiment 28, there is provided a method
for producing the organic EL display element described in any one
of Embodiments 12 to 18, characterized in that a transparent second
conductive layer is formed on the substrate and a lamination layer
comprising a first conductive layer and a capping layer is formed
on the substrate, the second conductive layer is used as a second
electrode, and the lamination layer is patterned so that the
lamination layer is used as a part of wires extending from the
first conductive layer to a connection terminal.
[0060] According to an Embodiment 29, there is provided the method
for producing the organic EL display element according to the
Embodiment 28, wherein the transparent second conductive layer is
formed on the substrate, the second conductive layer is patterned
to use it as the second electrode, the first conductive layer and
the capping layer are formed as the lamination layer, and then,
patterning is carried out to the lamination layer.
[0061] According to an Embodiment 30, there is provided an organic
EL display element comprising the organic EL display element
described in any one of Embodiments 12 to 18 and a driving circuit
connected to the display element so that a display is provided at a
luminance of at least 100 cd/m.sup.2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0062] FIG. 1 is a front view partly omitted showing an Embodiment
of a substrate with wires formed by using the laminate of the
present invention.
[0063] FIG. 2 is a cross-sectional view of the part taken along an
A-A' cutting-plane line in FIG. 1.
[0064] FIG. 3 is a cross-sectional view of the part taken along a
B-B' cutting-plane line in FIG. 1.
[0065] FIG. 4(a) is a diagram showing an ESCA depth profile before
a heat treatment of a laminate for the substrate with wires in
Example 3, and FIG. 4(b) is a diagram showing an ESCA depth profile
after the heat treatment of the laminate for the substrate with
wires in Example 3.
[0066] FIG. 5(a) is a photograph showing an observation result with
a laser microscope after the humidity resistance test of the
substrate with wires of the present invention in Example 12, and
FIG. 5(b) is a photograph showing an observation result with the
laser microscope after the humidity resistance test of the
substrate with wires in Example 15.
[0067] FIG. 6 is a plan view showing an Embodiment of the organic
EL display element according to the present invention.
[0068] FIG. 7 is a cross-sectional view partly omitted taken along
a C-C' cutting-plane line in FIG. 6.
[0069] FIG. 8 is a plan view of TEG for evaluating a wire
resistance.
[0070] FIG. 9 is a plan view of TEG for evaluating a contact
resistances of a cathode and a supplementary wire.
[0071] FIG. 10 is a cross-sectional view partly omitted taken along
a D-D' cutting-plane line in FIG. 9.
[0072] FIG. 11 is a current vs voltage characteristics diagram of a
contact TEG obtained in Example B2.
[0073] FIG. 12 shows a contact resistance of the contact TEG
obtained in Example B2.
[0074] FIG. 13 is a current vs voltage characteristics diagram of
the contact TEG obtained in Example B3.
[0075] FIG. 14 shows a contact resistance of the contact TEG
obtained in Example B3.
[0076] FIG. 15 is a photograph after evaluation to high temperature
and high humidity of a terminal portion of the organic EL display
element obtained in Example B4.
[0077] FIG. 16 is a photograph after evaluation to high temperature
and high humidity of a terminal portion of the organic EL display
element as a Comparative Example in Example B4.
[0078] FIG. 17 is a cross-sectional view of a cathode contact
portion of the organic EL display element prepared according to the
conventional technique.
[0079] FIG. 18 is a plan view of a terminal portion with TCP.
[0080] FIG. 19 is a cross-sectional view of the part taken along a
E-E' cutting-plane line in FIG. 18.
[0081] FIG. 20 is a flow chart showing a method for production
according to the present invention.
[0082] FIG. 21 is a cross-sectional view showing a structural
example 1 of the laminate of the present invention;
[0083] FIG. 22 is a cross-sectional view showing a structural
example 2 of the laminate of the present invention.
[0084] FIG. 23 is a perspective view of an Embodiment of the
substrate with wires of the present invention.
[0085] FIG. 24 is a cross-sectional view partly omitted showing a
forming step 1 for a cathode side circuitous circuit of an organic
EL display element.
[0086] FIG. 25 is a cross-sectional view partly omitted showing a
forming step 2 for the cathode side circuitous circuit of the
organic EL display element.
[0087] FIG. 26 is a cross-sectional view partly omitted showing a
forming step 3 for the cathode side circuitous circuit of the
organic EL display element.
[0088] FIG. 27 is a cross-sectional view partly omitted showing a
forming step 4 for the cathode side circuitous circuit of the
organic EL display element.
[0089] FIG. 28 is a cross-sectional view partly omitted showing a
forming step 5 for the cathode side circuitous circuit of the
organic EL display element.
[0090] FIG. 29 is a diagrammatical plan view in a manufacturing
step 1 of the organic EL display element of the present
invention.
[0091] FIG. 30 is a diagrammatical plan view in a manufacturing
step 2 of the organic EL display element of the present
invention.
[0092] FIG. 31 is a diagrammatical plan view in a manufacturing
step 3 of the organic EL display element of the present
invention.
[0093] FIG. 32 is a diagrammatical plan view in a manufacturing
step 4 of the organic EL display element of the present
invention.
[0094] FIG. 33 is a diagrammatical plan view in a manufacturing
step 5 of the organic EL display element of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0095] In the following, some practical embodiments of the present
invention will be described with reference to drawings, Examples
and so on. However, these drawings and Examples show
exemplification of the present invention and they do not limit the
scope of the present invention. Of course, another practical
embodiment belongs to the present invention as long as it meets the
spirit of the present invention.
[0096] The substrate used in the present invention is not
necessarily in a flat plate-like shape but may have a curved plane
or a different shape. As the substrate, there are a transparent or
opaque glass substrate, a ceramic substrate, a plastic substrate, a
metal substrate and so on.
[0097] When the substrate is used for an organic EL display element
having a structure that emission of light is caused from a
substrate side, it is preferable that the substrate is transparent.
In particular, the substrate is preferably a glass substrate from
viewpoints of strength and heat resistance. As the glass substrate,
a transparent colorless soda lime glass substrate, quartz glass
substrate, borosilicate glass substrate and non-alkali glass
substrate can be mentioned. As the glass substrate used for the
organic EL display element, it preferably has a thickness of
0.2-1.5 mm from viewpoints of strength and transmittance.
[0098] The laminate for forming a substrate with wires according to
the present invention is a laminate of at least two layers
comprising essentially a conductive layer containing Al or an Al
alloy (hereinbelow, it may be referred to as the Al series metal)
as the major component, formed on the substrate and a capping layer
containing Ni--Mo as the major component, formed on the conductive
layer. Since the conductive layer is the Al series metal,
low-resistivitization of wires can be achieved. In particular, an
Al--Nd alloy is preferable since hillocks of Al can be prevented
while it can keep low resistance characteristics. The Al alloy is
an alloy of Al and a metal such as Nd, Ag, Cu or the like, which is
of little risk in increasing the resistance of the wires.
[0099] The Al series metal layer may contain Ti, Mn, Si, Cu, Na or
O as impurities, and it is preferable that the content of
impurities is 1 mass % or less in total. The content of Al in the
Al alloy layer is preferably 80-100 mass %, more preferably, 90-100
mass % from the viewpoint of reducing the resistance of the
wires.
[0100] The film thickness of the conductive layer is preferably
100-500 nm, more preferably, 100-400 nm, further preferably,
150-400 nm, particularly preferably, 150-300 nm so that a
sufficient conductivity and excellent feasibility of patterning can
be obtained.
[0101] The capping layer formed on the conductive layer is a layer
containing a Ni--Mo alloy as the major component. Since the Ni--Mo
alloy layer is excellent in humidity resistance, the capping layer
can reduce the resistance of the wires; can prevent an aluminum
oxide layer from occurring on the surface of the Al series metal
layer, and suppress an increase of the contact resistance.
[0102] Accordingly, reliability to an electronic device using such
substrate with wires can be improved. Further, an obtainable
laminate can allow precise patterning. In addition, when the Ni--Mo
alloy layer undergoes patterning by a photolithographic method, the
conductive layer (the Al series metal layer) and the capping layer
(the Ni--Mo alloy layer) can be etched at substantially the same
rate by using the same etching liquid (aqueous solution of acid).
Namely, patterning can be conducted together with the conductive
layer.
[0103] A large difference in the etching rate between the
conductive layer and the capping layer is not preferable because
over-etching or a residue is resulted during the formation of the
wires. The etching rate of the Ni--Mo alloy layer can easily be
adjusted by changing the proportion of composition of Ni and Mo
depending on a kind of the etching liquid. When the proportion of
Mo to Ni is large, the etching rate becomes higher.
[0104] The film thickness of the capping layer is preferably 10-200
nm, more preferably, 15-50 nm from viewpoints of humidity
resistance and feasibility of patterning.
[0105] The content of Ni in the Ni--Mo alloy layer is preferably
20-90 mass %, more preferably, 55-75 mass %. If the content of Ni
is less than 20 mass %, the humidity resistance of the Ni--Mo alloy
layer is insufficient, and if it exceeds 90 mass %, the etching
rate by the etching liquid is low and it is difficult to adjust it
to the same rate as for the conductive layer. Further, the content
of Mo in the Ni--Mo alloy layer is preferably 10-80 mass %, more
preferably, 20-40 mass %.
[0106] If the content of Mo is less than 10 mass %, the etching
rate by the etching liquid is low and it is difficult to adjust it
to the same rate as the conductive layer. If it exceeds 80 mass %,
the humidity resistance of the Ni--Mo alloy layer is insufficient.
It is preferable that the total content of Ni and Mo in the Ni--Mo
alloy layer is 90-100 mass %.
[0107] The Ni--Mo alloy layer may contain a kind of or at least 2
kinds of metal such as Ti, V, Cr, Fe, Co, Zr, Nb, Ta, W or the like
in a range that the humidity resistance and the feasibility of
etching are not deteriorated, e.g., in an amount of not more than
10 mass %.
[0108] The laminate for forming a substrate with wires of the
present invention can be formed by a sputtering method. For
example, it can be formed by a combined steps: a step of forming a
conductive layer on a surface of a glass substrate by sputtering
with an Al series metal target in an inert gas atmosphere and a
step of forming a capping layer on the conductive layer by
sputtering with a Ni--Mo alloy series target.
[0109] The Al series metal target is, for example, an Al metal
target, an Al alloy target containing Nd, an Al non-alloy target
containing Nd, or the like. The Ni--Mo alloy target is, for
example, a Ni--Mo alloy target, a Ni--Mo alloy target containing
Fe, a Ni--Mo non-alloy target containing Fe, or the like.
[0110] As the Ni--Mo non-alloy target containing Fe, there is such
one formed by combining in a mosaic form Ni plates, Mo plates and
Fe plates having smaller surface areas than the surface area of the
target, or such one formed by combining a Ni--Mo alloy target plate
and a Fe plate, for example. The sputtering method permits the
formation of a laminate for forming a substrate with wires which
has a uniform film thickness over a large surface area.
[0111] When an Al layer as the conductive layer and a Ni--Mo alloy
layer as the capping layer are formed in the laminate for the
substrate with wires of the present invention, the following method
can be used, for example.
[0112] An Al series target and a Ni--Mo alloy series target are
fixed separately to the cathode of a d.c. magnetron sputtering
device, and a substrate is fixed to the substrate holder. Then, air
in the deposition chamber is evacuated and an Ar gas is introduced
as sputtering gas. Although He, Ne or Kr gas can be used instead of
the Ar gas, the Ar gas is preferable because it provides a stable
discharge and is economical. The sputtering pressure is preferably
0.1 to 2 Pa and the backpressure is preferably 1.times.10.sup.-6 to
1.times.10.sup.-2 Pa. The substrate temperature is preferably from
the room temperature to 400.degree. C. A higher deposition
temperature is preferably because it may reduce the resistance.
However, it increases the surface roughness. When it is necessary
to make the surface roughness small, the substrate temperature
should be lowered. The lowering of the surface roughness has an
advantage that the coverage of the Ni--Mo layer formed on the Al
layer becomes good.
[0113] When the Al metal layer is formed, an Al metal target may be
used, and when the Al alloy layer is formed, Al and other metal for
forming an alloy may be used as separate targets to form the alloy
layer. However, it is preferable, from viewpoints of
controllability of the composition of the conductive layer and
improvement of uniformity, that an Al alloy having a predetermined
composition is previously prepared and the alloy is used for the
target.
[0114] First, sputtering is conducted by using the Al metal target
to form an Al metal layer as the conductive layer on the substrate.
Then, sputtering is conducted to the layer by using the Ni--Mo
series target to form a Ni--Mo alloy layer whereby a laminate is
produced.
[0115] As described above, the laminate of the present invention
comprises two layers formed on the substrate as the basic
structure. However, the present invention is not limited to such
structure, but includes a structure having three or more layers
comprising other layers as described below. It is preferable to
form these other layers by a sputtering method.
[0116] The laminate of the present invention may have an
anti-Ni-diffusion layer having a composition different from the
capping layer, between the Ni--Mo alloy layer (the capping layer)
and the Al metal layer (the conductive layer) containing Al or an
Al alloy as the major component. When a heat treatment is conducted
under the condition that the capping layer is in contact with the
conductive layer, Ni diffuses from the capping layer to the
conductive layer whereby the resistance of the conductive layer
increases. The increase of the resistance can be suppressed by
providing the anti-Ni-diffusion layer. It is preferable that the
anti-Ni-diffusion layer is also formed by a sputtering method. In
the formation of the anti-Ni-diffusion layer, it is preferable to
use the same conditions (the sputtering pressure and so on) as the
Al layer.
[0117] The film thickness of the anti-Ni-diffusion layer is
preferably 10-200 nm from viewpoints of a barrier effect and
feasibility of patterning, more preferably, 15-80 nm, particularly
preferably, 15-50 nm.
[0118] It is preferable that the anti-Ni-diffusion layer comprises
a Mo series metal layer containing Mo as the major component
because it can be etched together with the capping layer and the
conductive layer. When the Mo series metal layer is formed as the
anti-Ni-diffusion layer between the conductive layer and the
capping layer, Mo is exposed at a patterned cross-sectioned portion
after patterning. However, there is no substantial change of the
humidity resistance because the major part of the Mo series metal
layer is covered with the capping layer and the conductive
layer.
[0119] However, the anti-Ni-diffusion layer can contain, other than
Mo, a kind or at least two kinds of metal such as Nb, Ta, V, W, Cr,
Zr, Ti or the like in a range of from 2 to 20 mass % in order to
improve further the humidity resistance. If it contains an element
or elements in an amount of less than 2 mass %, the effect of
improving the humidity resistance by the addition of element or
elements is not sufficient. On the other hand, if more than 20 mass
%, there is difficulty in manufacturing because the feasibility of
patterning becomes worse. The content of Mo in the Mo series alloy
layer containing Mo as the major component is preferably 80 to 98
mass %.
[0120] In the laminate of the present invention, the capping layer
is preferably subjected to a process of oxidizing or nitriding, or
processes of oxidizing and nitriding, oxidizing and carbonizing,
nitriding and carbonizing or oxidizing, nitriding and carbonizing.
Namely, the increase of the resistance can be prevented likewise
the anti-Ni-diffusion layer by conducting such process or processes
in the formation of the capping layer so that the Ni--Mo alloy
layer is rendered to be an oxidized, nitrided, oxynitrided,
oxycarbonized, carbonitried or oxycarbonitrided Ni--Mo alloy
layer.
[0121] Such process or processes are conducted by a method using a
mixed gas comprising a reactive gas such as O.sub.2, N.sub.2, CO,
CO.sub.2 or the like and an Ar gas, as sputtering gas, in the
formation of the Ni--Mo alloy layer by sputtering. The content of
the reactive gas is preferably 5 to 50 volume % from the viewpoint
of an anti-Ni-diffusion effect, more preferably, 20 to 40 volume
%.
[0122] Further, the laminate of the present invention may have a
tin-doped indium oxide layer (ITO layer). In this case, there is a
disadvantage that the Al series metal layer has a large contact
resistance to the ITO layer. Accordingly, it is practically
preferable for the laminate to have a structure comprising a
capping layer/a conductive layer/an underlayer/an ITO layer/a
substrate by interposing the underlayer.
[0123] The ITO layer can be used as a transparent electrode.
Accordingly, after the ITO layer has been formed on the substrate
in the laminate of the present invention, when a necessary portion
is masked in the formation of the underlayer, the conductive layer
and the capping layer, there is no underlayer, conductive layer and
capping layer under the mask, and only the ITO layer exists. Thus,
it can be used as the electrode. If necessary, an organic layer can
be formed on the electrode to form an organic EL display element.
On the other hand, since there are the underlayer, the conductive
layer and the capping layer on the ITO layer in the unmasked
portion, the ITO layer as the electrode can be connected to the
underlayer, the conductive layer and the capping layer as wires,
without any step.
[0124] The ITO layer can be formed on, for instance, a glass
substrate by using an electron beam method, a sputtering method, an
ion plating method or the like. The ITO layer can preferably be
formed by sputtering, using an ITO target containing SnO.sub.2 in 3
to 15 mass % based on the total amount of In.sub.2O.sub.3 and
SnO.sub.2, for instance. The sputtering gas is preferably a mixed
gas of O.sub.2 and Ar and the concentration of O.sub.2 gas is
preferably 0.2 to 2 volume %.
[0125] The film thickness of the ITO layer is preferably 50-300 nm,
more preferably, 100 to 200 nm.
[0126] Then, the conductive layer and the capping layer are formed
on the ITO film by sputtering to obtain the laminate for forming a
substrate with wires having the ITO layer.
[0127] The conductive layer has the disadvantage of large contact
resistance to the ITO layer. Accordingly, when the ITO layer is
formed between the substrate and the conductive layer, the
underlayer should be formed under the conductive layer in order to
prevent an increase of the contact resistance between the ITO layer
and wires. It is preferable that the underlayer is a layer
containing Mo or a Mo alloy as the major component. The layer
containing Mo or a Mo alloy as the major component means that the
content of Mo or a Mo alloy in the layer is 90 to 100 mass %.
Further, it is preferable to form the underlayer under the same
conditions (such as sputtering pressure and so on) as the Al
layer.
[0128] The film thickness of the underlayer is preferably 10 to 200
nm from viewpoints of a barrier effect and feasibility of
patterning, more preferably, 15 to 50 nm.
[0129] The Ni--Mo alloy layer is preferably used as the layer
containing Mo or the Mo alloy as the major component. When the
Ni--Mo alloy layer is used as the underlayer, the content of Ni in
the alloy layer is preferably 20 to 90 mass % in the all
components, more preferably, 55 to 75 mass %. The content of Mo is
preferably 10 to 80 mass % in the all components, more preferably,
20 to 40 mass %.
[0130] Further, a kind of or at least two kinds of metal such as
Ti, V, Cr, Fe, Co, Zr, Nb, Ta, W and so on may be contained in an
amount not to cause deterioration of the humidity resistance and
feasibility of patterning, e.g., in an amount of not more than 10
mass %.
[0131] The composition of the Ni--Mo alloy layer as the underlayer
formed under the conductive layer may be the same as or different
from the composition of the Ni--Mo alloy layer as the capping
layer. Use of the same composition allows using the same material
as the target, and is advantageous in economy. When compositions of
upper and lower Ni--Mo alloy layers are adjusted so that etching
rates for the Ni--Mo alloy layer (capping layer), the Al series
metal layer (conductive layer) and the Ni--Mo alloy layer
(underlayer) are increased in this order, the patterned portion can
be processed in a taper-like form in cross section. It is also
advantageous because the abrasion resistance and adhesive
properties can be improved. Further, an anti-Ni-diffusion layer may
be formed between the conductive layer and the Ni--Mo alloy layer
as the underlayer. The structure of the anti-Ni-diffusion layer is
the same as the anti-Ni-diffusion layer provided between the
conductive layer and the capping layer as describe before.
[0132] When the layer containing Mo or a Mo alloy as the major
component is formed as an underlayer under the conductive layer, Mo
exposes in the cross-sectioned portion of a patterned portion after
the patterning. However, an improvement of the humidity resistance
can be kept because the major portion of the layer containing Mo or
a Mo alloy as the major component is covered with the substrate or
the ITO film, and the conductive layer.
[0133] In the formation of a laminate without the anti-Ni-diffusion
layer, when an oxidizing process, a nitriding process or a
carbonizing process (or a combination of these processes) is
conducted, a laminate having desired characteristics can be formed.
In this case, there is an advantage of obtaining the laminate with
a smaller number of layers.
[0134] Or, when a laminate made of metal comprising 4 layers or 5
layers is formed, there is an advantage that a continuous
production is possible by using an in-line type continuous film
forming system.
[0135] Further, the laminate of the present invention may have a
silica layer between the conductive layer and the substrate. The
silica layer may be in contact with the substrate or may be without
contact thereto. Generally, the silica layer is formed by
sputtering a silica target. When a glass substrate is used as the
substrate, the deterioration of the conductive layer is prevented
because an alkali component in the glass substrate moves to the
conductive layer. It is preferable that the film thickness is 5 to
30 nm.
[0136] The laminate of the present invention is of a low
resistance; is excellent in feasibility of patterning and has a
high humidity resistance. When such laminate is used for an organic
EL display element, the organic EL display element having a long
lifetime and an improved luminescent characteristics is obtainable
because it is provided with wires of highly reliable and low
resistance. The thus obtained laminate of the present invention is
preferably subjected to etching by a photolithographic method in
order to form a substrate with wires.
[0137] A photoresist is coated on the capping layer providing the
outermost surface of the laminate; a pattern for wires is formed by
baking, and an unnecessary portion of the metal layer is removed
according to the pattern of the photo-resist by an etching liquid,
whereby the substrate with wires is formed. The etching liquid is
preferably an aqueous solution of acid such as phosphoric acid,
nitric acid, acetic acid, sulfuric acid or hydrochloric acid, or a
mixture of these components, ammonium cerium nitrate, perchloric
acid or a mixture of these components.
[0138] A mixed solution of water and phosphoric acid, nitric acid,
acetic acid or sulfuric acid is preferable. A mixed solution of
water and phosphoric acid, nitric acid or acetic acid is more
preferable.
[0139] In the formation of the substrate with wires, each layer of
the laminate, for example, each layer of (1) capping
layer/conductive layer/substrate, (2) capping layer/conductive
layer/underlayer/ITO layer/substrate or (3) capping
layer/anti-Ni-diffusion layer/conductive layer/anti-Ni-diffusion
layer/underlayer/ITO layer/substrate is subjected to etching to
have the same pattern.
[0140] When the laminate has the ITO layer, the capping
layer/conductive layer may be removed together with the ITO layer
by an etching liquid. Or, the capping layer and the conductive
layer may be previously removed and the ITO layer is separately
removed. Or, the ITO layer may be previously patterned; the
conductive layer and the capping layer are sputtered, and then,
portions of the capping layer/conductive layer excluding a wire
portion are removed.
[0141] In the next, a preferred example of producing a substrate
with wires and the laminate and an organic EL display element by
using the substrate according to the present invention will be
described with reference to FIGS. 1 to 3. However, the present
invention is not limited to such examples.
[0142] First, an ITO film is formed on a glass substrate 1. Etching
is conducted to the ITO film to form an ITO anode 3 of stripe
pattern. Then, a Ni--Mo alloy layer (not shown) is formed by
sputtering so as to cover the entire surface of the glass
substrate. On the alloy layer, a Mo series metal layer (not shown)
as the underlayer, an Al series metal layer 2a as the conductive
layer, a Mo series metal layer (not shown) as the anti-Ni-diffusion
layer and a Ni--Mo layer 2b as the capping layer are formed in this
order by sputtering to thereby obtain a laminate for forming a
substrate with wires. Of course, the ITO layer may be formed
entirely or partly on the glass substrate 1.
[0143] A photoresist is coated on the laminate. Unnecessary
portions of the metal layers are removed by etching according to
the pattern of the photoresist. When the photoresist is peeled off,
wires 2 comprised of the Ni--Mo alloy layer, the Mo series metal
layer, the Al series metal layer 2a, the Mo series metal layer and
the Ni--Mo alloy layer 2b is obtained. Then, a ultraviolet
ray-ozone treatment or an oxygen-plasma treatment is conducted to
the entirety of the laminate by irradiation and cleaning with
ultraviolet rays. In the irradiation and cleaning with ultraviolet
rays, ultraviolet rays are generally irradiated with a U.V. lamp to
remove organic matters.
[0144] Then, an organic layer 4 having a hole transport layer, a
light emission layer and an electron transport layer is formed on
the ITO anode 3. When a cathode separator (separator) is to be
formed, the separator is formed by photolithography before the
organic layer 4 is formed by vacuum deposition.
[0145] An Al cathode 5 as a cathode back-electrode is formed by
sputtering so as to cross perpendicularly to the ITO electrode 3
after the wires 2, the ITO electrode 3 and the organic layer 4 are
formed.
[0146] Then, the portion surrounded by a broken line is sealed with
resin to form a sealed can 6.
[0147] Since the substrate with wires of the present invention
comprises the above-mentioned laminate wherein Al or an Al alloy of
low resistance is used for the conductive layer and a Ni--Mo alloy
having a high humidity resistance is used for the capping layer, it
has a low resistance and is excellent in patterning, and has a high
humidity resistance whereby there is little possibility of causing
the deterioration of the wires.
[0148] Further, when the laminate of the present invention is used
for a substrate with wires for an organic EL display element, it is
necessary to conduct, to the substrate, a ultraviolet ray-ozone
treatment that is a special treatment for organic
electroluminescence. In this case, the substrate with wires of the
present invention has durability against such treatment.
[0149] By using the laminate of the present invention, the
substrate with wires having a low resistance, being excellent in
patterning, and having a high humidity resistance can be formed.
Further, a display of high precision and highly reliable can be
provided. In particular, an organic EL display element having a
long lifetime and being desired for lowering the resistance of the
wires in order to improve luminescence characteristics, can be used
effectively.
[0150] In the following, the present invention will be described by
several Examples. However, the present invention should not be
limited to these.
COMPARATIVE EXAMPLES 1-5
[0151] Soda lime glass substrates having a thickness of 0.7 mm, a
length of 100 mm and a width of 100 mm were cleaned. The glass
substrates were set on a sputtering device. A RF magnetron
sputtering was carried out by using a silica target to form a
silica layer having a thickness of 20 nm on each substrate. Thus,
glass substrates with silica layers were obtained.
[0152] Then, a d.c. magnetron sputtering was carried out by using
an ITO target (containing 10 mass % of SnO.sub.2 based on the total
amount of In.sub.2O.sub.3 and SnO.sub.2) to form an ITO layer
having a thickness of 160 nm, whereby glass substrates with an ITO
layer (referred simply to as the substrates) were obtained. As
sputtering gas, Ar gas containing 0.5 volume % of O.sub.2 gas was
used.
[0153] A d.c. magnetron sputtering was carried out in an Ar gas
atmosphere by using 5 kinds of targets to the entire surface
(excluding the portion used for holding the substrates) of the
glass substrates with ITO layers to thereby form 5 kinds of single
films as shown in Table 1. Thus, glass substrates with films were
obtained. The backpressure was 1.3.times.10.sup.-3 Pa, the
sputtering pressure was 0.3 Pa and the substrates were not heated.
The magnetron sputtering to an Ni target was possible since the
thickness of the target was reduced to 1 mm.
[0154] The film thickness, the sheet resistance, the etching rate
and the humidity resistance (1) of the glass substrates with films
were measured. Results are shown in Table 1.
[0155] The sheet resistance was measured by a four-probe method
with use of Loresta IP MCP-T250 manufactured by Mitsubishi
Petrochemical Co., Ltd.
[0156] The etching rate was obtained by measuring a time expended
until the film on each substrate was dissolved under the condition
that the substrates with films were dipped for 5 minutes in an
etching liquid comprising phosphoric acid, nitric acid, acetic acid
and water in proportion of 16:1:2:1 in volume ratio. The case of
incompletion of the etching even after 5 minutes was evaluated as
X.
[0157] Evaluation of the humidity resistance (1) was made by
measuring a change of the resistance after the glass substrates
with films were left one day under conditions of 60.degree. C. and
95% RH by using a constant temperature and constant humidity
chamber (PR-1S manufactured by Espec Co., Ltd). The case that the
change rate of the sheet resistance was less than 5% was evaluated
as .largecircle., and the case that the change rate of the sheet
resistance was at least 5% was evaluated as X.
[0158] It is understood from Table 1 that the Mo layer has a low
humidity resistance, and the Ni layer and the Ni--Mo alloy layer
have an excellent humidity resistance. In the case of the Mo layer,
corrosion could be observed visually in its surface. In cases of Ni
layer and the Ni--Mo alloy layer, on the other hand, corrosion
could not be observed visually in their surfaces.
[0159] The etching to the Ni layer was not finished even after
5-minutes dipping. On the other hand, the Ni--Mo alloy layer could
be etched at the same etching rate as the Al layer or faster than
it. Namely, excellent etching performance was exhibited. In
particular, when a Ni--Mo--Fe alloy target was used, substantially
the same etching rate as the Al layer could be obtained.
Accordingly, in Examples described below, a Ni--Mo--Fe alloy target
having a mass percentage of 65%-32%-3% (hereinbelow, it may be
referred to as the Ni--Mo target) was used in order to form a Mo
alloy layer. The layer formed by the Ni--Mo target is referred to
as the Ni--Mo alloy layer.
EXAMPLES 1-2
[0160] Soda lime glass substrates having a thickness of 0.7 mm, a
length of 100 mm and a width of 100 mm were cleaned. The glass
substrates were set on a sputtering apparatus. A RF magnetron
sputtering was carried out by using a silica target to form a
silica layer having a thickness of 20 nm on each substrate. Thus,
glass substrates with silica layers were obtained.
[0161] A d.c. magnetron sputtering was carried out in an Ar
atmosphere by using an Al metal target to the entire surface
(excluding the portion used for holding the substrates) of the
glass substrates with silica layers to thereby form Al layers
(conductive layers). The backpressure was 1.3.times.10.sup.-3 Pa,
the sputtering pressure was 0.3 Pa and the substrates were not
heated.
[0162] A d.c. magnetron sputtering was carried out in an Ar gas
atmosphere by using a Mo target (Example 1) or a Ni--Mo target
(Example 2) to glass substrates with conductive layers thus
obtained whereby a Mo layer (Example 1) or a Ni--Mo alloy layer
(Example 2) was formed as a capping layer. Thus, laminates for
substrates with wires were obtained. The backpressure was
1.3.times.10.sup.-3 Pa, the sputtering pressure was 0.3 Pa and the
substrates were not heated.
[0163] The film thickness, the humidity resistance (1), of the
laminates for substrates with wires, the sheet resistance before
heating and the heat resistance of the laminates were measured.
Results are shown in Table 2.
[0164] Evaluation of the humidity resistance (1) was made in the
same manner as Reference Example 1. When the capping layer was the
Mo layer (Example 1), corrosion could be observed visually in its
surface. However, when the capping layer was the Ni--Mo alloy layer
(Example 2), corrosion could not be observed visually in its
surface.
[0165] The heat treatment to the laminates was carried out by
leaving the laminates in a constant temperature chamber (PMS-P101
manufactured by Espec Co., Ltd.) at 320.degree. C. in the
atmosphere for 1 hour, and the sheet resistance of the laminates
before the heat treatment and the change rate of the resistance
before and after the heat treatment were measured. The case that
the change rate of the sheet resistance was not more than 10% was
evaluated as .largecircle.; the case that it exceeded 10% but not
more than 100% was as .DELTA., and the case that it exceeded 100%
was as X.
EXAMPLE 3
[0166] A d.c. magnetron sputtering was carried out in an Ar gas
atmosphere by using a Ni--Mo target to the entire surface
(excluding the portion used for holding the substrate) of glass
substrate with an ITO layer in Reference Example 1 to thereby form
a Ni--Mo alloy layer (an undercoat layer). Thus, a glass substrate
with an undercoat layer was obtained.
[0167] The backpressure was 1.3.times.10.sup.-3 Pa, the sputtering
pressure was 0.3 Pa and the substrate was not heated. Then, an Al
layer (a conductive layer) and a Ni--Mo alloy layer (a capping
layer) were formed on the undercoat layer under the same conditions
as Example 2 to thereby obtain a laminate for forming a substrate
with wires. The film thickness and the humidity resistance (1) of
the laminate, the sheet resistance before a heat treatment and the
heat resistance of the laminate were measured in the same manner as
Example 1. Table 2 shows a result.
[0168] FIGS. 4(a) and 4(b) show an ESCA depth profiles of the
laminate of Example 3 before and after the heat treatment. It is
understood that Ni metal diffuses into the Al layer (the conductive
layer) by the heat treatment in the laminate of Example 3.
EXAMPLES 4-7
[0169] A d.c. magnetron sputtering was carried out in an Ar gas
atmosphere by using a Mo target to form a Mo layer (an
anti-Ni-diffusion layer) on the undercoat layer of each of the
glass substrates with undercoat layers in Example 3. Then, an Al
layer (a conductive layer) was formed on the anti-Ni-diffusion
layer in the same manner as Example 2, and a Mo layer (an
anti-Ni-diffusion layer) was formed on the conductive layer under
the same conditions as the above-mentioned anti-Ni-diffusion
layer.
[0170] Further, a Ni--Mo alloy layer (a capping layer) was formed
on each of the anti-Ni-diffusion layers by using a Ni--Mo target
under the same conditions as Example 2 to obtain laminates for a
substrate with wires.
[0171] The film thickness and the humidity resistance (1) of the
laminates, the sheet resistance before a heat treatment and the
heat resistance of the laminates were measured in the same manner
as Example 1, Table 2 shows results.
[0172] It is clear from Table 2 and FIGS. 4(a) and 4(b) that the
capping layer comprising the Mo layer in Example 1 shows bad
humidity resistance, but the Ni--Mo alloy layer in Example 2 shows
excellent humidity resistance. Further, it is understood that when
a heat treatment is carried out in a state that the Ni--Mo alloy
layer is in contact with the Al layer as in Example 3, the heat
resistance becomes worse.
[0173] On the other hand, it is cleat from results of Examples 4-7
that the Mo layer interposed between the Ni--Mo alloy layer and the
Al layer prevents the deterioration of the heat resistance.
Further, it is understood that a good result can be obtained when
the film thickness of the Mo layer is preferably 10 nm or more and
60 nm or less.
EXAMPLES 8-11
[0174] Sputtering was carried out under the same conditions as in
Example 3 except that a mixed gas having the composition shown in
Table 3 was used instead of the Ar gas used in Example 3, as
sputtering gas for forming the undercoat layer and the capping
layer, to thereby obtain laminates for substrates with wires.
[0175] The film thickness and the humidity resistance (1) of the
laminates, the sheet resistance before a heat treatment and the
heat resistance of the laminates were measured in the same manner
as in Example 1, Table 3 shows results.
[0176] It is understood from Table 3 that when nitriding or
oxidizing/carbonizing are conducted to the Ni--Mo alloy layer, the
diffusion of Ni into the Al series metal layer is prevented and the
deterioration of the heat resistance can be prevented.
EXAMPLE 12
[0177] A mask pattern having a line/space of 25 .mu.m/65 .mu.m was
used for the laminate for forming a substrate with wires of Example
5. Patterning was carried out by using an Al etching liquid by a
photolithographic method to prepare a substrate with wires.
[0178] The film thickness of the laminate, the sheet resistance of
the laminate before the patterning and the change rate of the
resistance (heat resistance) of the laminate before and after the
heat treatment were measured in the same manner as Example 1. Table
4 shows a result.
[0179] In the evaluation of the feasibility of the patterning, the
distance of etching proceeded beyond the patterning line was
measured from a direction perpendicular to the line and an amount
of over-etching was observed. The case that an amount of
over-etching was 2 .mu.m or less was evaluated as .largecircle. and
the case that it was more than 2 .mu.m was evaluated as X.
[0180] The humidity resistance (2) of the substrate with wires
after the patterning was evaluated under conditions that the
substrate with wires was left one day at 60.degree. C. and 95% RH
by using a constant temperature/constant humidity chamber (PR-1S
manufactured by Espec Co., Ltd), and wires were observed with a
laser microscope. The case that no corrosion was recognized in the
wires was evaluated as .largecircle., and the case that corrosion
was recognized was evaluated as X. Table 4 shows a result of the
feasibility of patterning and the humidity resistance (2). Further,
FIG. 5(a) shows a result of observation of the substrate with wires
of Example 12 with a laser microscope (magnification: 500 times)
after the evaluation of the humidity resistance (2).
EXAMPLE 13
[0181] A d.c. magnetron sputtering was carried out in a mixed
Ar--CO.sub.2 gas atmosphere having the composition as shown in
Table 4 by using a Ni--Mo target to the entire surface (excluding
the portion used for holding the substrate) of the glass substrate
with an ITO layer in Reference Example 1 to thereby form a Ni--Mo
alloy layer (an undercoat layer). The backpressure was
1.3.times.10.sup.-3 Pa, the sputtering pressure was 0.3 Pa and the
substrate was not heated.
[0182] Then, an Al layer (a conductive layer) was formed on the
undercoat layer by using an Al metal target, and a Mo alloy layer
(an anti-Ni-diffusion layer) was formed on the Al layer (conductive
layer) by using a Mo target. Further, a Ni--Mo alloy layer (capping
layer) was formed on the anti-Ni-diffusion layer by using a Ni--Mo
target to thereby obtain a laminate for forming a substrate with
wires.
[0183] The film thickness of the laminate, the sheet resistance of
the laminate before the patterning and the change rate of the
resistance (heat resistance) of the laminate before and after a
heat treatment were measured in the same manner as Example 1. Table
4 shows a result.
[0184] Then, patterning was carried out under the same conditions
as the method in Example 12 to obtain a substrate with wires. The
feasibility of patterning and the humidity resistance (2) of the
substrate with wires were measured in the same manner as Example
12. Table 4 shows a result of evaluation. Further, the humidity
resistance (3) of the substrate with wires after the pattering of
the laminate was evaluated under the same conditions as the case of
the humidity resistance (2) except that the substrate was left for
5 days. Table 5 shows a result.
EXAMPLE 14
[0185] A d.c. magnetron sputtering was carried out in a mixed
Ar--CO.sub.2 gas atmosphere having the composition shown in Table 4
by using a Ni--Mo target to the entire surface (excluding the
portion used for holding the substrate) of the glass substrate with
an ITO layer in Reference Example 1 to thereby form a Ni--Mo alloy
layer (an undercoat layer). The backpressure was
1.3.times.10.sup.-3 Pa, the sputtering pressure was 0.3 Pa and the
substrate was not heated.
[0186] Then, an Al layer (a conductive layer) was formed on the
undercoat layer by using an Al metal target.
[0187] Further, a Ni--Mo alloy layer (a capping layer) was formed
on the conductive layer by using a d.c. magnetron sputtering method
using a Ni--Mo target in a mixed Ar--CO.sub.2 gas atmosphere having
the composition as shown in Table 4 to thereby obtain a laminate
for forming a substrate with wires. The film thickness of the
laminate, the sheet resistance of the laminate before the
patterning and the change rate of the resistance (heat resistance)
of the laminate before and after a heat treatment were measured in
the same manner as Example 1, Table 4 shows a result.
[0188] Then, patterning was carried out under the same conditions
as the method in Example 12 to obtain a substrate with wires. The
feasibility of patterning and the humidity resistance (2) of the
substrate with wires were measured in the same manner as Example 2.
Table 4 shows a result of evaluation.
EXAMPLE 15
[0189] A d.c. magnetron sputtering was carried out in an Ar gas
atmosphere by using a Mo target to the entire surface (excluding
the portion used for holding the substrate) of the glass substrate
with an ITO layer in Reference Example 1 to thereby form a Mo
layer. The backpressure was 1.3.times.10.sup.-3 Pa, the sputtering
pressure was 0.3 Pa and the substrate was not heated.
[0190] Then, an Al layer (a conductive layer) was formed on the
undercoat layer by using an Al metal target, and a Mo layer (a
capping layer) was formed on the conductive layer by using a Mo
target to obtain a laminate for forming a substrate with wires. The
film thickness of the laminate, the sheet resistance of the
laminate before the patterning and the change rate of the
resistance (heat resistance) of the laminate before and after a
heat treatment were measured in the same manner as Example 1, Table
4 shows a result.
[0191] Then, patterning was carried out under the same conditions
as the method in Example 12 to obtain a substrate with wires. The
feasibility of patterning and the humidity resistance (2) of the
substrate with wires were measured in the same manner as Example
12. Table 4 shows a result of evaluation. Further, FIG. 5(b) shows
a result of observation of the substrate with wires of Example 15
with a laser microscope (magnification: 500 times) after the
evaluation of the humidity resistance (2).
[0192] In view of Table 4 and FIG. 5(b), it is understood that the
capping layer comprising a Mo layer has a low humidity
resistance.
EXAMPLE 16
[0193] Sputtering was carried out under the same conditions as in
Example 13 except that the anti-Ni-diffusion layer in Example 13
was not formed, to form a laminate according to the present
invention. The film thickness of the laminate, the sheet resistance
of the laminate before the patterning and the change rate of the
resistance (heat resistance) of the laminate before and after a
heat treatment were measured in the same manner as Example 1, Table
4 shows a result.
[0194] Then, patterning was carried out under the same conditions
as the method in Example 13 to obtain a substrate with wires. The
feasibility of patterning, the humidity resistance (2) and the
humidity resistance (3) of the substrate with wires were measured
in the same manner as Example 13. Table 5 shows a result. The
humidity resistance (2) is obtained through a test of one day and
the humidity resistance (3) is obtained through a test of
consecutive 5 days. In the Table, .largecircle. means no corrosion,
.DELTA. means slight corrosion and X means corrosion.
EXAMPLE 17
[0195] The anti-Ni-diffusion layer in Example 13 was formed by
using a Mo--Nb alloy target in which the content of Nb was 5 mass
%. Sputtering was carried out under the same conditions as Example
13 except that the anti-Ni-diffusion layer was a Mo--Nb alloy layer
to thereby form a laminate. The film thickness of the laminate, the
sheet resistance of the laminate before the patterning and the
change rate of the resistance (heat resistance) of the laminate
before and after a heat treatment were measured in the same manner
as Example 1. Table 4 shows a result.
[0196] Then, patterning was carried out under the same conditions
as the method in Example 13 to obtain a substrate with wires. The
feasibility of patterning, the humidity resistance (2) and the
humidity resistance (3) of the substrate with wires were measured
in the same manner as Example 13. Table 5 shows a result of
evaluation.
EXAMPLE 18
[0197] The anti-Ni-diffusion layer in Example 13 was formed by
using a Mo--Nb alloy target in which the content of Nb was 10 mass
%. Sputtering was carried out under the same conditions as Example
13 except that the anti-Ni-diffusion layer was a Mo--Nb alloy layer
to thereby form a laminate. The film thickness of the laminate, the
sheet resistance of the laminate before the patterning and the
change rate of the resistance (heat resistance) of the laminate
before and after a heat treatment were measured in the same manner
as Example 1, Table 4 shows a result.
[0198] Then, patterning was carried out under the same conditions
as the method in Example 13 to obtain a substrate with wires. The
feasibility of patterning, the humidity resistance (2) and the
humidity resistance (3) of the substrate with wires were measured
in the same manner as Example 13. Table 5 shows a result.
[0199] From Table 5, it is understood that the anti-Ni-diffusion
layer comprising a MoNb alloy further improves the humidity
resistance.
EXAMPLE 19
[0200] Sputtering was carried out under the same conditions as
Example 13 except that the temperature of the substrate in Example
13 was 200.degree. C., to obtain a laminate. The film thickness of
the laminate, the sheet resistance of the laminate before the
patterning, the feasibility of patterning, the humidity resistance
(2) and the humidity resistance (3) of the laminate were measured
in the same manner as Example 13. Table 5 shows a result.
[0201] The surface roughness (Ra) was measured with an atomic force
microscope (Nano Scope IIIa manufactured by Digital Instrument
Inc.). Ra in Example 13 was 3 nm and Ra in Example 19 was 21 nm.
From these results, it is understood that when the substrate is
heated, the resistance decreases. On the other hand, it is
understood that when the substrate is heated, the surface roughness
increases.
[0202] In the above-mentioned Examples, when a process of
oxidizing, nitriding or carbonizing or processes of oxidizing and
nitriding, nitriding and carbonizing, or oxidizing, nitriding and
carbonizing are conducted, an amount of these atoms contained in
the thus formed metal film is considered to be, for instance, from
several % to about 30%.
[0203] FIGS. 21 and 22 are cross-sectional views of a part of the
laminate of the present invention. FIG. 21 shows a laminate having
a three-layer structure of laminate films 35, e.g., a layered
structure of NiMo--O.sub.x/Al series metal/NiMo--N.sub.y. FIG. 22
shows a four-layer structure of laminate films 35, e.g.,
NiMo--O.sub.x/Al series metal/Mo/NiMo or NiMo--O.sub.x/Al series
metal/MoNb/NiMo. Further, the laminate includes a five-layer
structure of laminate films, e.g., NiMo--O.sub.x/Mo/Al series
metal/Mo/NiMo.
[0204] FIG. 23 is a diagram showing a portion around a connection
terminal of the organic EL display element. An external connection
lead 41 is connected to a connection terminal according to the
present invention.
[0205] In the following, explanation will be made about Examples B1
to B4 for forming organic EL display elements. Examples B1 to B4
relate to passive matrix driving type organic EL display elements.
However, these techniques can, of course, be applied to TFT driving
type organic EL display elements using electrodes of low
resistance.
EXAMPLE B1
[0206] FIG. 6 is a plan view showing an example of the organic EL
display element of the present invention. FIG. 7 is a
cross-sectional view taken along C-C' in FIG. 6. In FIG. 6, a
counter substrate and TCP are omitted from the Figure. FIG. 20 is a
flowchart of a method for forming the organic EL display element of
the present invention. In the following, description will be made
as to steps of FIG. 20 sequentially with reference to FIGS. 6 and
7.
[0207] Further, each state of the organic EL display element
corresponding each step is shown in partly cross-sectional views of
FIGS. 24 to 28, and plan views are shown in FIGS. 29 to 33. A
transparent conductive film (ITO layer) is formed on a substrate
followed by patterning the film to thereby form an electrode layer
usable as an anode 20a. A connection terminal 20b for the anode is
located at an end portion of the substrate. Then, a lamination film
35 of metal is formed on the substantially entire surface of the
substrate (FIG. 29). Thereafter, the lamination film 35 is
patterned to form supplementary wires 30 (FIG. 30).
[0208] Then, an insulation film 40 is formed so that display
portions of anodes 20a are covered with the insulation film 40 so
as to cover the entirety of the substrate surface including the
supplementary wires 30 and the anodes 20a to form apertures 40a for
pixels (FIG. 31). Then, a pattern of insulation film having the
pixel apertures 40a and insulation film apertures 40b is formed
(FIG. 32). Further, a pattern of metal is formed for cathodes 70 so
as to obtain electric contact to the supplementary wires 30 at
these portions (FIG. 33). End portions of the supplementary wires
are patterned to form connection terminals and are connected to an
external driving circuit.
[0209] In the laminate of the present invention, patterning of the
anodes may be carried out first and then, forming the metal
lamination film on the substrate (see FIG. 29). Or, a desired film
may optionally be formed depending on the size of the substrate
surface.
[0210] First, a conductive layer is formed on a silica coat layer
of a glass substrate 1 having the silica coat layer at Step
S.sub.1. This conductive layer corresponds to the second electrode
layer as described before. As the glass substrate, soda lime glass
may be used, for example. The thickness of the silica coat layer is
generally 5 to 30 nm, and the silica coat layer can be formed by,
e.g., a sputtering method.
[0211] The conductive layer generally has translucency. The meaning
of translucency should include the case having a certain degree of
translucency other than the case that the transmittance of light is
high as 90 to 100% like a so-called a transparent conductive layer.
The second electrode layer is preferably a transparent conductive
layer because it performs sufficiently function as a display
element.
[0212] The thickness of the conductive layer is generally 50 to 300
nm, more preferably, 100 to 200 nm. Typically, an ITO film prepared
by a d.c. sputtering method is used. In this example, an ITO film
is used. The conductive layer can generally be formed by a physical
vapor phase epitaxial method (PVD) such as a vacuum deposition
method, ion plating method or the like.
[0213] Then, at Step S.sub.2, a resist was patterned by a
photolithographic process. At Step S.sub.3, the ITO film was
etched. Then, at Step S.sub.4, the resist is peeled off to obtain
the anodes 20a and connection terminals 20b for the anodes. Any
known resist may be used unless it is against the spirit of the
present invention. For the etching, a mixed aqueous solution of
hydrochloric acid and nitric acid can be used. In order to peel off
the resist, any known parting agent may be used unless it is
against the spirit of the present invention.
[0214] Then, at Step S.sub.5, a lamination film of metal including
a capping layer comprising a low resistance layer of Al or an Al
alloy and a Ni alloy is formed by d.c. sputtering. It is preferable
to use Al form the low resistance layer in order to reduce the
resistance of wires. In this case, it is possible to use an Al
alloy such as AlNd or AlSiCu to improve the anti-corrosion
characteristics. A detailed example of film formation will be
described later.
[0215] Then, at Step S.sub.6, the resist is patterned by a
photolithographic method. At Step S.sub.7, the lamination film of
metal is etched. At Step S.sub.8, the resist is peeled off. For the
resist used for forming the lamination film, any known resist may
be used unless it is against the spirit of the present
invention.
[0216] In the etching, an etching liquid composed of a mixed
aqueous solution of phosphoric acid, acetic acid and nitric acid
can be used, for example. In order to peel off the resist, any
known parting agent may be used unless it is against the spirit of
the present invention. Laminated films in the present invention can
be etched altogether by this etching liquid. Thus, the
supplementary wires 30 can be formed. Further, an internal
patterned portion 30a located at an inner side of the element and
the connection-terminal side patterned portion 30b are formed.
[0217] For the patterning process for the ITO film (Steps S.sub.2
to S.sub.4) and the patterning process for the lamination film of
metal (Step S.sub.6 to S.sub.8), it is possible to form
sequentially the ITO film and the lamination film of metal by
sputtering and then, patterning is conducted to the lamination film
of metal and the ITO film in this order. However, it is preferable
to use a manufacturing method in which patterning to ITO is
conducted beforehand because of the reason as follows. In ITO
etching after the patterning of the supplementary wires, the
etching liquid used for ITO is of a strong acid. If there is pin
holes in the resist, there is a possibility of losing the pattern
for supplementary wires.
[0218] Then, at Step S.sub.9, spin coating of, e.g., a
photosensitive polyimide film as the insulation film is carried
out. At Step S.sub.10, patterning is carried out by a
photolithographic method. At Step S.sub.11, the film is cured to
thereby obtain a pattern of insulation film 40 having apertures 40a
for pixels at pixel portions as shown in FIGS. 6 and 7. The film
thickness of the pattern of insulation film 40 after curing is
generally about 1.0 .mu.m. When an aperture for a pixel is about
300 .mu.m.times.300 .mu.m, the contact portion between a cathode
and a supplementary wire should be 200 .mu.m.times.200 .mu.m or
less because there is no substantial effect to the size of the
display element.
[0219] Then, at Step S.sub.12, spin coating of, e.g., a
photosensitive acrylic resin is carried out; patterning of the
formed resin is carried out by a photolithographic method followed
by curing whereby a pattern 50 for separating cathodes is formed
(see FIG. 9). When the pattern for separating cathodes is formed, a
negative type photosensitive resin is preferably used so as to
provide a reverse taper structure. Use of the negative type
photosensitive resin causes insufficient curing at a deeper
position when light is irradiated from an upper side of the resin.
As a result, the cross-sectional area of a lower portion of the
cured portion is narrower than that of an upper portion of the
cured portion in view of the above. Such structure is referred to
as the reverse taper structure.
[0220] In using such reverse taper structure, when a mask for
forming the cathodes is to be formed by vacuum deposition in a
later process, vacuum deposition does not reach a hidden portion in
view of the above. Accordingly, it is possible to separate cathodes
individually. There is a case that the above-mentioned
photosensitive polyimide resin and photosensitive acrylic resin are
interchangeable. Further, any known resin for the insulation film
such as epoxy resin, phenol resin or the like can be used unless it
is against the spirit of the present invention.
[0221] Then, at Step S.sub.13, irradiation of oxygen plasma is
carried out by using, e.g., a parallel plate type RF plasma (high
frequency plasma) device to modify the surface of the ITO film.
Then, at Step S.sub.14, an organic EL layer 60 and the cathodes 70
are formed by vacuum deposition through the mask by using, e.g., a
vacuum deposition device (see FIGS. 27 to 28 and FIGS. 29 to
33).
[0222] These cathodes correspond to the first electrode layer of
the present invention. The organic EL layer often comprises an
interface layer, a hole transport layer, a light emitting layer, an
electron injection layer and so on as structural elements. However,
the organic EL layer may have a different layer structure. The
thickness of the organic EL layer is generally 100 to 300 nm.
[0223] By forming the insulation film pattern, end portions of the
anodes 20a are covered with the insulation film. Accordingly, the
surface of the organic EL layer in contact with the anodes 20a is
made flat whereby a possibility of breaking of the organic EL layer
or a cathode due to concentration of the electric field or the like
can be reduced, and the withstand voltage of an anode and a cathode
can be improved. Al is often used for the cathodes. However, alkali
metal such as Li or the like or an alloy of Ag, Ca, Mg, Y, In or
including these can be used instead of Al.
[0224] The thickness of a cathode is generally 50 to 300 nm. It is
not necessary that a cathode consists of solely Al or an Al alloy,
but the portion of the conductive layer to be connected to a
supplementary wire may contain Al or an Al alloy. There is a case
that cathode is formed by a physical vapor phase epitaxial method
such as sputtering, ion plating or the like, other than the
above-mentioned method.
[0225] Thus, patterned organic EL portions 60 formed of the organic
EL layer and the patterned cathode portions 70 are formed (see a
plan view of FIG. 6). By applying the lamination film of the
present invention to the supplementary wires and the terminal
portions of the cathodes, they are of a low resistance and it is
possible to maintain low contact resistance characteristics to the
cathodes and the connection terminal of a driving circuit. Further,
an organic EL display element with supplementary wires having
reliable contact characteristics and a driving circuit for driving
the organic EL display element can be obtained.
[0226] At S.sub.15, a resin film in which CaO is mixed as a
hydroscopic agent 100 is bonded to a counter substrate 80. For the
bonding, it is desirable for the counter substrate 80 that the
glass substrate is caved partially by sand blasting or the like.
Then, a ultraviolet curing type resin is dispensed at a peripheral
portion of the substrate of the element and the counter substrate 8
is bonded thereto. Ultraviolet rays are irradiated thereto to form
a peripheral seal 90 to thereby fix the counter substrate 80. Such
processes are carried out in a nitrogen atmosphere so that moisture
and oxygen do not enter into the display panel. Then, the substrate
is cut to form each panel, and terminal portions are exposed.
[0227] At S.sub.16, an external driving circuit is mounted.
Specifically, an anisotropic conductive film 110 is bonded to the
connection-terminal side patterned portion 30b which provides
connection terminals, and then, wires of copper sheet for TCP are
arranged so as to overlap the terminals with TCP side connection
wires followed by bonding by heat pressing.
[0228] Here, explanation will be made as to a sealing process and a
consecutive mounting process, which are important in the organic EL
display element, with reference to FIG. 17. Since the organic EL
display element is deteriorated by moisture, the counter substrate
80 is sealed with the peripheral seal 90. As a sealing material
used for this purpose, a photosensitive epoxy resin is
preferred.
[0229] Next, explanation will be made as to the hydroscopic agent
for the organic EL display element. In the organic EL display
element, it is preferable to incorporate the hydroscopic agent in
order to remove moisture during operations of sealing. As the
hydroscopic agent, there are barium oxide, calcium oxide, zeolite
and so on. For example, a hydroscopic film 100 which calcium oxide
is mixed in a resin film bonded to a concave portion at an inner
surface side of the counter substrate 80 (see FIG. 17).
[0230] Then, the anodes and the cathodes are connected to an
external driving circuit. Then, the driving circuit formed in a TCP
structure is mounted on terminal portions of the anodes and the
cathodes. Further, as the method for connecting the organic EL
display element to the driving circuit, terminals connected
electrically to wires in the element are provided and the terminals
are connected to the driving circuit.
[0231] In order to perform a high density connection, there are a
method that the external driving circuit is connected to a side of
a polyimide film having patterned thin copper wires and the other
side is connected to element terminals via an anisotropic
conductive film (ACF) (a TCP mounting) or a method that a metal
bump is provided at bare tips of the driving circuit and is
connected to terminals via ACF (COG mounting).
[0232] TCP is a structure that a driving IC and a connection wire
are provided on a film such as polyimide. The terminal portion in
the TCP mounting is shown in a plan view of FIG. 18 and a
cross-sectional view taken along a E-E' cutting-plane line in FIG.
18 is shown in FIG. 19. Terminals 30C are formed on the glass
substrate 1, an anisotropic conductive film (ACF) 110 is bonded
thereon, and connection wires 150 formed on a polyimide film of
TCP120 are bonded thereon so as to obtain alignment to the
terminals. The anisotropic conductive film is constituted by
dispersing conductive particles 130 in a resin. As the resin, an
epoxy resin is generally used, and as the conductive particles, Ni
or Au-coated plastic particles or Ni particles are used.
[0233] The TCP is formed by forming driving ICs 140 and connection
wires 150 on a polyimide tape 160. The connection wires 150 are
made mainly of Cu. The TCP connecting process is as follows. First,
ACF is bonded temporarily to the terminal portion. The temperature
for temporarily bonding is generally about 50 to 150.degree. C. and
the pressure is generally 1 to 2 MPa. Then, after adjusting the
positional relation between the connection wires 150 of TCP and the
terminals 30C, the TCP is bonded permanently. The temperature for
permanently bonding is generally about 150 to 250.degree. C. and
the pressure is generally 2 to 3 MPa. After the permanently
bonding, the conductive particles between the connection wires 150
and the terminals 30C are crushed to obtain electric connection.
After the mounting is completed, the mounted portion may be covered
with a resin to prevent corrosion. Generally, a silicone type resin
or an ultraviolet curing type epoxy resin is used.
[0234] Thus, the organic EL display element is prepared. Further, a
test element group (hereinbelow, referred to as TEG) is sometimes
formed in order to confirm function of individual parts and to
obtain the performance of each process. TEG produced in the same
manner as the above-mentioned process is shown in FIGS. 8 and
9.
[0235] Although TEG is formed with constructional materials of a
part, it is formed via all processes until S.sub.15 in FIG. 20.
These processes allow evaluation of not only performance and
workability of the materials but also influence to the materials,
suffered from the process history. A pattern of supplementary wire
30 as shown in FIG. 8 is formed by processes of forming the ITO
film, removing it by etching and forming a lamination film of
metal. By using this pattern, the resistance of a wire constituted
by the lamination film can be obtained. Here, the width of the wire
is 40 .mu.m and the length of the wire is 6.8 mm. The structure in
FIG. 9 is formed according to processes of S.sub.1 to S.sub.14. The
shape in cross-section taken along a D-D' cutting-plane line in
FIG. 9 is shown in FIG. 10.
[0236] First, the ITO film is removed at S.sub.1 to S.sub.4. Then,
patterning is conducted to the lamination film to form the
supplementary wires 30 at S.sub.5 to S.sub.8, and the pattern of
insulation film 40 and patterned apertures 40b of insulation film
are formed at S.sub.9 to S.sub.11. A patterned aperture of
insulation film has a square shape having a side of 200 .mu.m.
Then, the cathode separating pattern 50 is formed at S.sub.12. This
pattern is provided with slits 50a near apertures of insulation
film.
[0237] Then, the pattern for the cathodes 70 is formed at S.sub.14
to complete TEG. In this TEG, the supplementary wires 30 formed by
patterning the lamination film of metal are connected to the
patterned cathodes 70 at apertures 40b of insulation film. When a
voltage is applied across adjacent supplementary wires (patterned
lamination film) 30, a current flows from the patterned aperture
40b to the patterned cathode and further flows to the adjacent
supplementary wires (patterned lamination film) 30 via the slits
50a of patterned partitions.
[0238] At this moment, the current flows in the connection between
two patterned metal portions (parts of lamination film) and the
patterned cathode. Accordingly, it is possible to calculate the
resistance of the connecting portion (contact resistance) by
subtracting resistances of the other portions. The reason that the
cathode separating pattern is provided, is as follows. A developing
solution may stay at a patterned aperture 40b of insulation film at
the time of developing the cathode separating pattern, and there is
a possibility of causing adverse influence to the contact
resistance. For this, faithful reproduction is necessary. Thus, it
is possible to evaluate resistances of wires and the contact
resistance between a supplementary wire and a cathode.
[0239] According to the above-mentioned explanation, an organic EL
display element was prepared. The contents of each process are the
same as above unless specifically described.
EXAMPLE B2
[0240] According to the above-mentioned explanation, TEG for the
wire resistance and TEG for the contact resistance shown in FIGS.
8, 9 and 10 are prepared.
[0241] First, according to S.sub.1 to S.sub.4, an ITO film having
150 nm was formed and it was removed partially. Then, films of
NiMo, Mo, Al, Mo and NiMo were formed sequentially by d.c.
sputtering. When the underlayer of NiMo was formed, CO.sub.2 was
fed for oxidizing and carbonizing.
[0242] The NiMo layer is 50 nm, Mo is 200 nm, and the Al layer is
400 nm in thickness. These laminated films can be etched all
together with an aqueous solution of phosphoric acid, acetic acid
and nitric acid. By these treatments, a pattern of laminated metal
3 was obtained. Then, a pattern of insulation film 40 was obtained.
In FIG. 8, the pattern of insulation film is not formed at this
moment. Then, a cathode separating pattern 50 was obtained. In the
same manner as above, the cathode separating pattern is not formed
in FIG. 8. Slits 50a of the cathode separating pattern are of 300
.mu.m.
[0243] Then, irradiation of oxygen plasma was carried out to modify
the surface of the ITO film by using a parallel plate type RF
plasma device. Specifically, a plasma processing of RIE (reactive
ion etching) mode was conducted for 60 sec under plasma processing
conditions of a flow rate of oxygen of 50 sccm (50 mL/min in a
standard condition), a total gas pressure of 6.7 Pa and 1.5 kW.
[0244] Then, by using a vapor deposition device, vapor deposition
of Al was carried out for cathode through a mask in 300 nm to
obtain a patterned cathode 70. Thus prepared TEG for the wire
resistance was measured by a four-terminal method to find
25.5.OMEGA.. In conversion of the obtained resistance into the
sheet resistance, it was 0.15.OMEGA./.quadrature.. The heat
resistance of the film just after sputtering was
0.13.OMEGA./.quadrature..
[0245] This revealed that wires having low resistance were formed
although there was found a certain increase of the resistance in
processes for forming the organic EL display element. FIG. 11 shows
current vs voltage characteristics with respect to the TEG for the
contact resistance, and FIG. 12 shows the contact resistance. The
contact resistance is obtained by subtracting the voltage in the
wire portion at the normal temperature from the obtained
resistance.
[0246] A voltage was applied to adjacent patterned metal portions
of TEG with a probe. As a result, the terminal was burned off at
the contact position between the probe and the terminal at 4.8 V,
and it was impossible to apply a higher voltage. As is understood
from the result of measurement that when the above-mentioned
five-layered lamination film is applied to supplementary wires, the
contact resistance is low as about 0.5 to 3.0.OMEGA., and a current
of 350 mA or higher would be able to feed thereto. The fact that
the increase of the current is gradually suppressed, is considered
that the temperature of the wire portion is increased by the
current and the resistance is increased.
[0247] In the evaluation of a similar pattern made of Cr, the
contact resistance could be controlled to be about 10.OMEGA..
However, when a current of about 10 mA was fed, the pattern was
burned off at the contact portion.
[0248] Thus, by applying the above-mentioned lamination film of
metal to supplementary wires for the organic EL display element,
they showed a low resistance and a low contact resistance in
comparison with the conventional wires made of Cr. Accordingly, a
display allowing a large current flow and a display of high
luminance and high duty could be fabricated.
EXAMPLE B3
[0249] TEG was prepared by using another lamination film of metal
in the same manner as Example B1. The lamination film of metal used
was obtained by forming NiMo, Al and NiMo sequentially. In the
formation of the underlayer of NiMo, CO.sub.2 was supplied for
oxidizing and carbonizing. When the capping layer of NiMo was to be
formed, N.sub.2 was supplied for nitriding. The NiMo layer is 50 nm
and the Al layer is 400 nm in thickness. The other processes are
the same as in Example B1.
[0250] In the measurement of thus prepared TEG for the wire
resistance by a four-terminal method, the resistance was
18.7.OMEGA.. In conversion of the measured resistance to the sheet
resistance, 0.11.OMEGA./.quadrature. is obtainable. FIG. 11 shows
current-voltage characteristics with respect to the TEG for contact
resistance, and FIG. 12 shows the contact resistance. In this
Example, the wire was burnt off at its positive side in the
application of 4.2 V, and it was impossible to apply a higher
voltage. By applying the lamination film to supplementary wires for
the organic EL display element, a display having performance
comparable with or higher than the case of Example B1 could be
prepared.
EXAMPLE B4
[0251] According to the before-mentioned explanation, an organic EL
display element and TEG were prepared. The method for preparing TEG
is omitted. FIG. 6 is a plan view of the organic EL display element
in this example, and FIG. 7 is a cross-sectional view taken along
C- in FIG. 6.
[0252] First, an ITO film of 150 nm was formed on a silica coat
layer of a soda lime glass substrate 1 of 0.7 mm thick, having the
silica coat layer of 20 nm formed by sputtering, by d.c.
sputtering. Then, patterning of resist was carried out by a
photolithographic process. Thereafter, the ITO film was etched, by
using a mixed aqueous solution of hydrochloric acid and nitric
acid, followed by peeling off the resist, whereby a pattern of
anodes 20a and connection terminals 20b for the anodes was
obtained.
[0253] As the resist, a phenol novolack resin was used, and as the
resist parting agent, monoethanolamine was used. Then, lamination
films of metal of NiMo, Al, Mo and NiMo were formed in this order.
In film thicknesses of lamination films of metal, the NiMo layer is
50 nm, the Mo layer is 20 nm and Al is 360 nm. The NiMo layer as an
underlayer was oxidized and carbonized by feeding CO.sub.2.
[0254] Then, patterning of the resist was carried out by a
photolithographic method. The lamination films of metal were etched
by using an etching solution composed of a mixed aqueous solution
of phosphoric acid, acetic acid and nitric acid, and the resist was
peeled off, whereby an inner side pattern 30a and a connection
terminal side pattern 30b were formed to provide the supplementary
wires 30. As the resist, a phenol novolack resin was used, and as
the resist parting agent, monoethanolamine was used. Then, a
pattern of insulation film 40 having apertures 40a for pixels was
obtained. This pattern of insulation film 40 is provided on the
patterned supplementary wires 30 to form supplementary wire contact
portions 40b, as shown in FIG. 6.
[0255] An aperture for a pixel was of 300 .mu.m.times.300 .mu.m and
a contact portion 40b between a cathode and a supplementary wire
was of 200 .mu.m.times.200 .mu.m. Thereafter, a cathode separating
pattern 50 was obtained. Then, irradiation of oxygen plasma was
carried out by using a parallel plate type RF plasma device to
modify the surface of the ITO film, and an organic EL layer and
cathodes were formed by vacuum deposition through a mask by using a
vacuum deposition device. Specifically, plasma processing of RIE
(reactive ion etching) mode was carried out for 60 sec under the
plasma process conditions of a flow rate of oxygen of 50 sccm (50
mL/min in a standard state), a total gas pressure of 6.7 Pa and 1.5
kW.
[0256] Then, an interface layer composed of copper phtalocyanine
(hereinbelow, referred to as CuPc), a hole transport layer composed
of N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (hereinbelow,
referred to as .alpha.-NPD), a light emitting layer composed of
tris(8-quinolinolato)aluminum (hereinbelow, abbreviated as Alq), an
electron implanting layer composed of LiF and cathodes of Al were
formed to have 10 nm, 60 nm, 50 nm, 0.5 nm and 200 nm,
respectively.
[0257] Among these, the interface layer of CuPc, the hole transport
layer of .alpha.-NPD, light emitting layer of Alq and the electron
implanting layer of LiF constitute the organic EL layer. With
respect to the hole transport layer, a triphenylamine type material
such as triphenyldiamine (hereinbelow, referred to as TPD) can be
used instead of .alpha.-NPD.
[0258] Then, an organic EL pattern 60 comprising the organic EL
layer and a pattern of cathodes 70 were formed. Thereafter, the
organic EL display element was bonded to a counter substrate 80
with a peripheral seal 90 comprising the ultraviolet curing type
resin. Specifically, a film containing CaO as a hydroscopic agent
100 was attached to the counter substrate and the ultraviolet
curing type resin was applied to a peripheral portion of the
organic EL display element by using a dispenser. These two
substrates were bonded mutually by irradiating ultraviolet rays. As
the ultraviolet curing type resin, Nagase-Chiba XNR5516 was
used.
[0259] Then, an anisotropic conductive film is bonded to the
terminal portion, and TCP is connected to the terminal portion via
the film. Specifically, the anisotropic conductive film 110 was
bonded temporarily to the mounted terminal portion. As the
anisotropic conductive film, Anisolm 7106U manufactured by Hitachi
Chemical Co., Ltd. is usable, for example. The temperature for
temporarily bonding is 80.degree. C., the pressing pressure is 1.0
MPa and the pressing time is 5 sec.
[0260] Then, TCP including a driving circuit is bonded permanently
to the connection terminal portion. The temperature for permanently
bonding is 170.degree. C., the pressing pressure is 2.0 MPa and the
pressing time is 20 sec. Thus prepared organic EL display element
has supplementary wires of low resistance and low contact
resistance and terminals having excellent humidity resistance.
[0261] For the laminate according to the present invention, TEG
using a metal film was prepared in the same manner as mentioned
above. The wire resistance was 0.14.OMEGA./.quadrature.. Further,
the sheet resistance at the sputtering was
0.11.OMEGA./.quadrature.. The contact resistance obtained from the
contact TEG was 0.5 to 0.8.OMEGA./200 .mu.m.quadrature., and the
metal pattern was burned down at about 350 mA.
[0262] Further, the terminal portion without mounting on the
substrate of this Example was kept under high temperature/high
humidity conditions of 80.degree. C. and 90% RH. As Comparative
Examples, terminal portions made of metal of MoNb (10 atom %) and
Al, MoNb (10 atom %) were evaluated as well as the above. In this
case, the film thickness of MoNb was 70 nm and the film thickness
of Al was 350 nm. FIGS. 15 and 16 show states of corrosion after
100 hours. FIG. 15 shows the pattern of lamination films of this
Example and FIG. 16 shows the lamination films formed by MoNb and
Al.
[0263] Thus, it is understood that in the case of using the
lamination film according to the present invention, the degree of
corrosion can be reduced in comparison with the case of using MoNb
as the capping film. Further, when the mounted terminal portion was
observed after 700 hours by removing mounted FPC and ACF. As a
result, the degree of corrosion could further be reduced.
[0264] This suggests that the NiMo alloy as the capping layer has
excellent anti-corrosion characteristics. Further, when a pattern
of the laminated metals is formed, Mo in the anti-Ni-diffusion
layer exposes at an end of the pattern. When the Mo is replaced by
a metal having improved anti-corrosion characteristics like MoNb,
the diffusion of Ni into Al can be prevented, and corrosion can be
suppressed.
[0265] Thus, by using the laminate of the present invention, it is
possible to form a useful substrate with wires having a low
resistance, being excellent in patterning performance and having a
high humidity resistance. Further, a display of high performance
and reliability can be prepared. In particular, the present
invention is useful for an organic EL display element having a long
lifetime and being expected for low-resistivitization of wires in
order to improve light emitting characteristics. TABLE-US-00001
TABLE 1 Film Sheet Humidity Reference Composition of thickness
resistance Etching rate resistance Example target (mass %) (nm)
(.OMEGA./.quadrature.) (nm/sec) (1) 1 Ni 200 0.44 X .largecircle. 2
72.5Ni--24.5Mo--3Fe 118 10 0.7 .largecircle. 3 65Ni--32Mo--3Fe 114
11 1.8 .largecircle. 4 Mo 200 0.75 6.7 X 5 Al 167 0.27 1.5
.largecircle.
[0266] TABLE-US-00002 TABLE 2 Sheet resistance before Humidity heat
Substrate Film thickness resistance treatment Heat Example
structure Film structure (nm) (1) (.OMEGA./.quadrature.) resistance
1 Glass/SiO.sub.2 Al/Mo 200/20 .largecircle. 0.24 .largecircle. 2
Glass/SiO.sub.2 Al/NiMo 200/20 .largecircle. 0.24 .DELTA. 3
Glass/SiO.sub.2/ITO NiMo/Al/NiMo 20/200/20 .largecircle. 0.22 X 4
Glass/SiO.sub.2/ITO NiMo/Mo/Al/Mo/NiMo 20/10/200/10/20
.largecircle. 0.22 .largecircle. 5 Glass/SiO.sub.2/ITO
NiMo/Mo/Al/Mo/NiMo 20/20/200/20/20 .largecircle. 0.20 .largecircle.
6 Glass/SiO.sub.2/ITO NiMo/Mo/Al/Mo/NiMo 20/30/200/30/20
.largecircle. 0.21 .largecircle. 7 Glass/SiO.sub.2/ITO
NiMo/Mo/Al/Mo/NiMo 20/50/200/50/20 .largecircle. 0.19
.largecircle.
[0267] TABLE-US-00003 TABLE 3 Proportion of supplied sputtering gas
in the formation of underlayer Sheet (Ni--Mo layer) resistance and
capping before Film layer (Ni--Mo heat Substrate Film thickness
layer) Humidity treatment Heat Example structure structure (nm) Ar
N.sub.2 CO.sub.2 resistance (1) (.OMEGA./.quadrature.) resistance 3
Glass/SiO.sub.2/ NiMo/Al/NiMo 20/200/20 100 0 0 .largecircle. 0.22
X ITO 8 Glass/SiO.sub.2/ NiMo/Al/NiMo 20/200/20 90 10 0
.largecircle. 0.21 .DELTA. ITO 9 Glass/SiO.sub.2/ NiMo/Al/NiMo
20/200/20 79 21 0 .largecircle. 0.23 .largecircle. ITO 10
Glass/SiO.sub.2/ NiMo/Al/NiMo 20/200/20 90 0 10 .largecircle. 0.23
.DELTA. ITO 11 Glass/SiO.sub.2/ NiMo/Al/NiMo 20/200/20 66 0 34
.largecircle. 0.23 .largecircle. ITO
[0268] TABLE-US-00004 TABLE 4 Substrate Film thickness Example
structure Film structure (nm) 12 Glass/SiO.sub.2/ITO
NiMo/Mo/Al/Mo/NiMo 20/20/200/20/20 13 Glass/SiO.sub.2/ITO
NiMo/Al/Mo/NiMo 20/200/20/20 14 Glass/SiO.sub.2/ITO NiMo/Al/NiMo
20/200/20 15 Glass/SiO.sub.2/ITO Mo/Al/Mo 20/200/20 Proportion of
Proportion of Sheet supplied sputtering supplied sputtering
resistance gas in the formation gas in the formation before of
underlayer of capping layer heat Feasibility Humidity (Ni--Mo
layer) (Ni--Mo layer) treatment Heat of resistance Example Ar
N.sub.2 CO.sub.2 Ar N.sub.2 CO.sub.2 (.OMEGA./.quadrature.)
resistance patterning (2) 12 100 0 0 100 0 0 0.22 .largecircle.
.largecircle. .largecircle. 13 66 0 34 100 0 0 0.22 .largecircle.
.largecircle. .largecircle. 14 66 0 34 79 21 0 0.23 .largecircle.
.largecircle. .largecircle. 15 100 -- -- 100 -- -- 0.22
.largecircle. .largecircle. X
[0269] TABLE-US-00005 TABLE 5 Proportion of supplied sputtering gas
in the formation of underlayer Substrate Film thickness (Ni--Mo
layer) Example structure Film structure (nm) Ar N.sub.2 CO.sub.2 13
Glass/SiO.sub.2/ITO NiMo/Al/Mo/NiMo 20/200/20/20 66 0 34 16
Glass/SiO.sub.2/ITO NiMo/Al/NiMo 20/200/20 66 0 34 17
Glass/SiO.sub.2/ITO NiMo/Al/Mo-5Nb/NiMo 20/200/20/20 66 0 34 18
Glass/SiO.sub.2/ITO NiMo/Al/Mo-10Nb/NiMo 20/200/20/20 66 0 34 19
Glass/SiO.sub.2/ITO NiMo/Al/Mo/NiMo 20/200/20/20 66 0 34 Proportion
of Sheet supplied sputtering resistance gas in the formation before
of capping layer heat Feasibility Humidity Humidity (Ni--Mo layer)
treatment Heat of resistance resistance Example Ar N.sub.2 CO.sub.2
(.OMEGA./.quadrature.) resistance patterning (2) (3) 13 100 0 0
0.22 .largecircle. .largecircle. .largecircle. .DELTA. 16 100 0 0
0.22 .DELTA. .largecircle. .largecircle. .largecircle. 17 100 0 0
0.22 .largecircle. .largecircle. .largecircle. .largecircle. 18 100
0 0 0.22 .largecircle. .largecircle. .largecircle. .largecircle. 19
100 0 0 0.20 .largecircle. .largecircle. .largecircle.
.largecircle.
* * * * *