U.S. patent application number 11/184080 was filed with the patent office on 2006-01-26 for color organic el display and method for manufacturing the same.
This patent application is currently assigned to DENSO CORPORATION. Invention is credited to Koji Ino, Taizo Ishida, Shoichi Kawai, Shigeru Miyaji, Kahoru Mori, Ryonosuke Tera.
Application Number | 20060017383 11/184080 |
Document ID | / |
Family ID | 35656418 |
Filed Date | 2006-01-26 |
United States Patent
Application |
20060017383 |
Kind Code |
A1 |
Ishida; Taizo ; et
al. |
January 26, 2006 |
Color organic EL display and method for manufacturing the same
Abstract
A color organic EL display includes: a substrate; a color filter
layer disposed on the substrate; a gas barrier layer disposed on
the color filter layer; and an organic EL structural body disposed
on the gas barrier layer. The substrate and the color filter layer
provide an underlayer of the gas barrier layer. The underlayer is a
degassed underlayer. The gas barrier layer is provided by an atomic
layer deposition method at a temperature equal to or lower than a
decomposition starting temperature of the color filter layer.
Inventors: |
Ishida; Taizo;
(Okazaki-city, JP) ; Mori; Kahoru; (Toyokawa-city,
JP) ; Miyaji; Shigeru; (Obu-city, JP) ; Kawai;
Shoichi; (Kuwana-city, JP) ; Tera; Ryonosuke;
(Toyota-city, JP) ; Ino; Koji; (Kariya-city,
JP) |
Correspondence
Address: |
POSZ LAW GROUP, PLC
12040 SOUTH LAKES DRIVE
SUITE 101
RESTON
VA
20191
US
|
Assignee: |
DENSO CORPORATION
Kariya-city
JP
|
Family ID: |
35656418 |
Appl. No.: |
11/184080 |
Filed: |
July 19, 2005 |
Current U.S.
Class: |
313/512 ;
257/100; 257/98; 313/112; 427/66; 428/917 |
Current CPC
Class: |
H01L 27/322 20130101;
H01L 51/5256 20130101 |
Class at
Publication: |
313/512 ;
428/917; 313/112; 257/098; 257/100; 427/066 |
International
Class: |
H05B 33/00 20060101
H05B033/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 14, 2005 |
JP |
2005-35891 |
Jul 20, 2004 |
JP |
2004-211593 |
May 30, 2005 |
JP |
2005-157722 |
Claims
1. A color organic EL display comprising: a substrate; a color
filter layer disposed on the substrate; a gas barrier layer
disposed on the color filter layer; and an organic EL structural
body disposed on the gas barrier layer, wherein the substrate and
the color filter layer provide an underlayer of the gas barrier
layer, the underlayer is a degassed underlayer, and the gas barrier
layer is provided by an atomic layer deposition method at a
temperature equal to or lower than a decomposition starting
temperature of the color filter layer.
2. The display according to claim 1, further comprising: an
overcoat layer disposed between the color filter layer and the gas
barrier layer so that the substrate, the color filter layer and the
overcoat layer provide the underlayer of the gas barrier layer,
wherein the overcoat layer is made of organic material, and the gas
barrier layer is provided by the atomic layer deposition method at
the temperature equal to or lower than a decomposition starting
temperature of the overcoat layer.
3. The display according to claim 2, wherein the color filter layer
and the overcoat layer are degassed by discharging water molecules
at 200.degree. C. in vacuum, and the discharged water molecules are
equal to or smaller than 2.times.10.sup.16 molecules per
mm.sup.3.
4. The display according to claim 1, wherein the gas barrier layer
is made of at least one material selected from the group consisting
of Al.sub.2O.sub.3, TiO.sub.2, SiN, SiO.sub.2, SiON, ZrO.sub.2,
MgO, CaO, GeO.sub.2, HfO.sub.2 and ZnO.
5. The display according to claim 1, wherein the gas barrier layer
has a film thickness equal to or thinner than 100 nm.
6. The display according to claim 5, wherein the gas barrier layer
has a film thickness equal to or thinner than 60 nm.
7. The display according to claim 1, wherein the gas barrier layer
is made of a multi-layered film including an Al.sub.2O.sub.3 layer
and a TiO.sub.2 layer.
8. The display according to claim 7, wherein the Al.sub.2O.sub.3
layer of the gas barrier layer has a total film thickness defined
as X, the TiO.sub.2 layer of the gas barrier layer has a total film
thickness defined as Y, and the thicknesses of X and Y have a
relationship of
37.gtoreq.3.times.10.sup.8.times.X+1.4.times.10.sup.9.times.Y.
9. The display according to claim 1, wherein the underlayer of the
gas barrier layer has a contact angle of a water drop equal to or
smaller than 10 degrees.
10. The display according to claim 1, wherein the substrate is made
of resin.
11. The display according to claim 1, further comprising: a
SiO.sub.2 layer, wherein the organic EL structural body includes a
transparent conductive film, and the SiO.sub.2 layer is disposed
between the gas barrier layer and the transparent conductive film
so that adhesiveness between the gas barrier layer and the
transparent conductive film is increased.
12. The display according to claim 1, wherein the gas barrier layer
includes a first film and a second film, which are stacked in this
order, the first film is capable of blocking gas generated from the
underlayer, and the second film has resistance to chemicals, which
are used after the gas barrier layer covers the color filter
layer.
13. The display according to claim 12, wherein the first film of
the gas barrier layer is made of at least one material selected
from the group consisting of Al.sub.2O.sub.3, TiO.sub.2, SiN,
SiO.sub.2, SiON, ZrO.sub.2, MgO, CaO, GeO.sub.2, HfO.sub.2 and
ZnO.
14. The display according to claim 12, wherein the second film of
the gas barrier layer is made of material, which is hardly
connected to a hydroxyl group for providing hydroxide.
15. The display according to claim 14, wherein the second film of
the gas barrier layer is made of at least one material selected
from the group consisting of TiO.sub.2, SiN, SiO.sub.2, SiON, and
Ta.sub.2O.sub.5.
16. The display according to claim 12, wherein the second film of
the gas barrier layer has a thickness equal to or larger than 5
nm.
17. The display according to claim 12, further comprising: an
insulation layer, wherein the second film of the gas barrier layer
has conductivity, and the insulation layer is disposed between the
second film and the organic EL structural body.
18. The display according to claim 17, wherein the insulation layer
is made of at least one material selected from the group consisting
of SiN, SiO.sub.2, SiON, Ta.sub.2O.sub.5, AlN, MgO, CaO, and
GeO.sub.2.
19. The display according to claim 1, wherein the substrate is made
of non-alkali glass.
20. The display according to claim 1, wherein the substrate
includes a glass substrate and an inorganic film, the inorganic
film covers the glass substrate, and the inorganic film includes no
alkali component.
21. A method for manufacturing a color organic EL display including
a substrate, a color filter layer, a gas barrier layer and an
organic EL structural body, which are stacked in this order,
wherein the substrate and the color filter layer provide an
underlayer of the gas barrier layer, the method comprising the
steps of: degassing the underlayer of the gas barrier layer; and
forming the gas barrier layer by an atomic layer deposition method
in such a manner that a plurality of raw material gases is
alternately introduced on the substrate under reduced pressure at a
temperature equal to or lower than a decomposition starting
temperature of the color filter layer.
22. The method according to claim 21, further comprising: forming
an overcoat layer disposed between the color filter layer and the
gas barrier layer so that the substrate, the color filter layer
and-the overcoat layer provide the underlayer of the gas barrier
layer, wherein the overcoat layer is made of organic material, and
the gas barrier layer is formed at the temperature equal to or
lower than a decomposition starting temperature of the overcoat
layer.
23. The method according to claim 21, wherein the step of degassing
is performed at a temperature equal to or lower than the
decomposition starting temperature of the color filter layer and
equal to or higher than a temperature of the substrate applied
after the step of degassing.
24. The method according to claim 21, wherein the step of degassing
is performed in dry atmosphere.
25. The method according to claim 22, wherein the step of degassing
is performed in such a manner that the color filter layer and the
overcoat layer is heated at 200.degree. C. in vacuum, and the step
of degassing is controlled to maintain the number of degassed water
molecules to be equal to or smaller than 2.times.10.sup.16
molecules per mm.sup.3.
26. The method according to claim 21, wherein the substrate is
preserved in dry atmosphere after the step of degassing and before
the step of forming the gas barrier layer.
27. The method according to claim 21, wherein the gas barrier layer
is formed at a temperature equal to or higher than a temperature of
the substrate applied after the step of forming the gas barrier
layer.
28. The method according to claim 21, wherein the gas barrier layer
is made of at least one material selected from the group consisting
of Al.sub.2O.sub.3, TiO.sub.2, SiN, SiO.sub.2, SiON, ZrO.sub.2,
MgO, CaO, GeO.sub.2, HfO.sub.2 and ZnO.
29. The method according to claim 21, wherein the gas barrier layer
is made of a multi-layered film including an Al.sub.2O.sub.3 layer
and a TiO.sub.2 layer.
30. The method according to claim 29, wherein the Al.sub.2O.sub.3
layer of the gas barrier layer has a total film thickness defined
as X, the TiO.sub.2 layer of the gas barrier layer has a total film
thickness defined as Y, and the thicknesses of X and Y have a
relationship of
37.gtoreq.3.times.10.sup.8.times.X+1.4.times.10.sup.9.times.Y
31. The method according to claim 21, wherein the underlayer of the
gas barrier layer has a contact angle of a water drop equal to or
smaller than 10 degrees.
32. The method according to claim 21, wherein the gas barrier layer
includes a first film and a second film, which are stacked in this
order, the first film is capable of blocking gas generated from the
underlayer, and the second film has resistance to chemicals, which
are used after the step of forming the gas barrier layer.
33. The method according to claim 32, wherein the first film of the
gas barrier layer is made of at least one material selected from
the group consisting of Al.sub.2O.sub.3, TiO.sub.2, SiN, SiO.sub.2,
SiON, ZrO.sub.2, MgO, CaO, GeO.sub.2, HfO.sub.2 and ZnO.
34. The method according to claim 32, wherein the second film of
the gas barrier layer is made of at least one material selected
from the group consisting of TiO.sub.2, SiN, SiO.sub.2, SiON, and
Ta.sub.2O.sub.5.
35. The method according to claim 21, wherein the gas barrier layer
is formed at the temperature equal to or higher than 200.degree. C.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on Japanese Patent Applications
No. 2004-211593 filed on Jul. 20, 2004, No. 2005-35891 filed on
Feb. 14, 2005, and No. 2005-157722 filed on May 30, 2005, the
disclosures of which are incorporated herein by references.
FIELD OF THE INVENTION
[0002] The present invention relates to a color organic EL display
and a method for manufacturing a color organic EL display.
BACKGROUND OF THE INVENTION
[0003] A color organic EL (i.e., electroluminescence) display
constituted by interposing a gas barrier layer between an organic
EL (electroluminescence) structural body and a color filter is
well-known.
[0004] This sort of color organic EL display is equipped with such
a structure that a color filter layer, a gas barrier layer, and an
organic EL structural body have been successively stacked on a
substrate.
[0005] Specifically, when an organic EL structural body for
emitting white light is combined with a color filter, the
below-mentioned structure of such a color organic EL display is
known. That is, a color filter layer, an overcoat layer, a gas
barrier layer, and an organic EL structural body element are
successively stacked on a transparent substrate, while the organic
EL structural body element emits white light.
[0006] In this color organic EL display, the gas barrier layer is
provided to prevent difficulties such as dark spots of the white
light emitting organic EL structural body and lowering of a
luminous efficiency thereof. These difficulties are caused by water
contents and the like, which are volatilized from the color filter
layer and the overcoat layer, which are made of resin.
[0007] Accordingly, as to the gas barrier layer, pin-holeless
characteristics are required, and superior step coverage thereof is
required. In addition to the above-described performance, other
performance such as transparent characteristics and flat
characteristics of surfaces is required.
[0008] Conventionally, as examples of gas barrier layers, one gas
barrier layer has been proposed which contains a silicon oxide and
is manufactured by executing a sputtering film forming method. For
example, Japanese Laid-open Patent Application No. Hei-11-260562
(which corresponds to EP 1115269-A1) discloses the structure. Also,
another gas barrier layer has been proposed in which an insulating
inorganic oxide layer is arranged as the gas barrier layer of a
color converting element (CCM). For example, Japanese Laid-open
Patent Application No. Hei-8-279394 (which corresponds to U.S. Pat.
No. 5,909,081) discloses this structure.
[0009] However, pin-holes are not considered in view of gas barrier
characteristics, as to these conventional gas barrier layers, so
that dark spots are easily produced in pixels, and such pixels
which cannot maintain desirable light emitting characteristics of
organic EL elements are readily produced.
[0010] As measures capable of solving such pin-hole problems
occurred in these gas barrier layers, one measure has been proposed
in which while a gas barrier layer is formed in a multilayer
structure, cleaning steps are carried out among film forming steps
for these plural gas barrier layers. For instance, Japanese
Laid-open patent Application No. 2003-229271 discloses this
structure. Another measure has been proposed in which while a gas
barrier layer is formed in a multilayer structure, resin layers are
distributed to the respective gas barrier layers. For instance,
Japanese Laid-open Patent Application No. 2003-282239 discloses the
structure.
[0011] Also, as the pin-hole measures, one measure has been
proposed in which a gas barrier layer is formed by a plasma CVD
method (P-CVD method), while this P-CVD method is capable of
forming a dense film, as compared with a sputtering method which
corresponds to a general-purpose film forming method for a gas
barrier layer. For example, Japanese Laid-open Patent Application
No. 2004-39468 discloses the structure.
[0012] However, the pin-hole measures described in the above
documents own problems as to productivity and cost aspects, since
the structures of the gas barrier layers and the manufacturing
processes thereof are complex.
[0013] Also, in the gas barrier layer manufactured by employing the
P-CVD method, when the gas barrier layer is formed by way of the
P-CVD method, the film forming operations are carried out at a
relatively low temperature, since heat resistance characteristics
as to the color filter layer and the overcoat layer are considered,
which are provided under the gas barrier layer. In this film
forming operation, since dense characteristics of these films are
deteriorated, gas barrier characteristics thereof are deteriorated.
As a result, these layer structures must be replaced by other
stacked layer structures, or the film thicknesses of these layers
must be made thicker, so that the problem as to the productivity
still remains, and thus, the manufacturing cost is increased.
SUMMARY OF THE INVENTION
[0014] In view of the above-described problem, it is an object of
the present invention to provide a color organic EL display
manufactured with low-cost and having simple structure.
[0015] A color organic EL display includes: a substrate; a color
filter layer disposed on the substrate; a gas barrier layer
disposed on the color filter layer; and an organic EL structural
body disposed on the gas barrier layer. The substrate and the color
filter layer provide an underlayer of the gas barrier layer. The
underlayer is a degassed underlayer. The gas barrier layer is
provided by an atomic layer deposition method at a temperature
equal to or lower than a decomposition starting temperature of the
color filter layer.
[0016] In the display, since the underlayer of the gas barrier
layer is degassed, the amount of gas discharged from the substrate
and the color filter layer is reduced. Further, since the gas
barrier layer is formed at the temperature equal to or lower than
the decomposition starting temperature of the color filter layer by
the atomic layer deposition method, the color filter layer is not
deteriorated with time. Therefore, the gas barrier layer can be
formed appropriately. Further, the gas barrier layer is formed by
the atomic layer deposition method, which is superior in coating
performance and minimum pin holes, compared with a vacuum
deposition method, a sputtering method, and a plasma CVD method;
and therefore, step coverage of the gas barrier layer is improved
and the number of pin holes is reduced. Furthermore, the gas
barrier layer can be formed by single process of the atomic layer
deposition method, so that productivity of the display is
increased, and the manufacturing cost is reduced. Furthermore, the
underlayer of the gas barrier layer is degassed so that the amount
of gas discharged from the underlayer is reduced. Therefore, the
gas barrier layer is prevented from expanding by the discharged
gas. Thus, the gas barrier layer is not peeled off. Thus, the color
organic EL display is manufactured with low-cost and having simple
structure.
[0017] Further, a method for manufacturing a color organic EL
display is provided. The display includes a substrate, a color
filter layer, a gas barrier layer and an organic EL structural
body, which are stacked in this order. The substrate and the color
filter layer provide an underlayer of the gas barrier layer. The
method includes the steps of: degassing the underlayer of the gas
barrier layer; and forming the gas barrier layer by an atomic layer
deposition method in such a manner that a plurality of raw material
gases is alternately introduced on the substrate under reduced
pressure at a temperature equal to or lower than a decomposition
starting temperature of the color filter layer.
[0018] In the display, the amount of gas discharged from the
substrate and the color filter layer is reduced. Further, the color
filter layer is not deteriorated with time. Therefore, the gas
barrier layer can be formed appropriately. Further, the gas barrier
layer is formed by the atomic layer deposition method, which is
superior in coating performance and minimum pin holes; and
therefore, step coverage of the gas barrier layer is improved and
the number of pin holes is reduced. Furthermore, productivity of
the display is increased, and the manufacturing cost is reduced.
Furthermore, the gas barrier layer is not peeled off. Thus, the
color organic EL display is manufactured with low-cost and having
simple structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The above and other objects, features and advantages of the
present invention will become more apparent from the following
detailed description made with reference to the accompanying
drawings. In the drawings:
[0020] FIG. 1 is a cross sectional view showing a color organic EL
display according to a first embodiment of the present
invention;
[0021] FIG. 2 is a cross sectional view showing the display taken
along line II-II in FIG. 1;
[0022] FIG. 3 is a graph explaining results of TDS analysis,
according to the first embodiment;
[0023] FIG. 4 is a graph showing a relationship between a baking
time of a degassing process and the number of degassed water
molecules, according to the first embodiment;
[0024] FIG. 5 is a graph showing a relationship between film
thickness and total stress in a TiO.sub.2/Al.sub.2O.sub.3
multi-layered film, according to the first embodiment;
[0025] FIG. 6 is a cross sectional view showing a color organic EL
display according to a second embodiment of the present
invention;
[0026] FIG. 7 is a cross sectional view showing a color organic EL
display according to a third embodiment of the present
invention;
[0027] FIG. 8 is a table showing the number of pin holes in a gas
barrier layer of different sample, according to the first
embodiment;
[0028] FIG. 9 is a table showing a peeling off of the gas barrier
layer in different degassing condition, according to the first
embodiment;
[0029] FIG. 10 is a table showing a crack in the gas barrier layer
having different film thickness, according to the first
embodiment;
[0030] FIG. 11 is a table showing an average of variation of
contact angle in different cleaning condition, according to the
first embodiment; and
[0031] FIG. 12 is a table showing a peeling off of the gas barrier
layer in different mounting condition and different cleaning
condition, according to the first embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0032] The Inventors of the present invention could succeed in
inventive researches of color organic EL displays.
[0033] That is, the reason why dark spots of color organic EL
displays are produced and durability thereof is deteriorated during
durability test is given in the below-mentioned explanations, while
the color organic EL displays are manufactured by combining organic
EL structural bodies with color filters. That is, gas such as water
contents which are contained in the color filters and the overcoats
may penetrate through the gas barrier layers, and then, may be
reached to the organic EL structural bodies.
[0034] Under such a circumstance, firstly, the amounts of gas
contained in underlayer portions (for instance, color filter layers
and overcoat layers) of the gas barrier layers must be lowered.
Secondly, the gas components produced from the underlayer portions
must be cut off by such a gas barrier layer having no pin-hole,
which can be realized in a simple forming process.
[0035] The Inventors have considered various researches, and thus,
could conceive the present invention based upon the above-described
inventive idea.
[0036] Further, in order to form a gas barrier layer, such a
low-temperature atomic layer growing method is employed which is
capable of realizing such a film that a film forming material can
have a superior covering characteristic, and pin-holes are reduced
as being permitted as possible, as compared with those of a vacuum
vapor deposition method, a sputtering method, and a plasma CVD
method. As a result, the formed film (gas barrier layer) can
effectively represent a gas barrier function capable of
interrupting gasses produced from the underlayer portion
thereof.
[0037] However, as a result of investigations made by the
Inventors, in the steps subsequent to the step for forming the gas
barrier layer, for instance, in such steps for cleaning the
substrate, in the electrode forming step, in the insulating layer
forming step, in the organic EL film forming step, various sorts of
medicines are utilized. As a result, there are some possibilities
that the gas barrier layer may be damaged by the relevant
medicines, depending upon a material of this gas barrier layer.
[0038] For instance, in such a case that the gas barrier layer is
manufactured by way of the low-temperature atomic layer growing
method which is executed at such a low temperature lower than, or
equal to the decomposition starting temperature of color filter
layers in the respective means, an amorphous alumina
(Al.sub.2O.sub.3) film is generally employed as the gas barrier
layer in view of cost and a film forming stability. This amorphous
alumina film has no problem as to the gas barrier characteristic
capable of cutting off the gasses produced from the underlayer
portion of this gas barrier layer.
[0039] However, as a result of investigations made by the
Inventors, the below-mentioned difficulty may occur when the
amorphous alumina film is processed. That is, the amorphous alumina
film is formed on a glass substrate where both the color filter
layers and an overcoat layer have been formed by executing the
low-temperature atomic layer growing method, and thereafter, this
formed amorphous alumina film is combined with the hydroxyl group
(--OH), so that this amorphous alumina film may produce such a
stable hydroxide as Al.sub.2(OH).sub.3 with respect to the medicine
process operations. These medicine process operations are carried
out in the substrate cleaning step, the electrode forming step, the
insulating layer forming step, the organic EL film forming step,
and the like.
[0040] In such a case of the stable hydroxide, the amorphous
alumina film functioning as the gas barrier layer is altered,
and/or is decomposed, so that there are some problems that the film
thickness thereof is decreased, and the gas barrier characteristic
of this gas barrier layer is deteriorated.
[0041] The following fact can be revealed. That is, the amorphous
alumina film may be very easily solved with respect to alkali and
acid. Especially, this amorphous alumina film may be readily
damaged with respect to warmed water having a temperature higher
than, or equal to 50.degree. C., an alkaline detergent, and an
alkaline processing fluid.
[0042] The reason why the amorphous alumina film may be readily
damaged in the warmed water is given as follows: That is, if a
temperature of water is equal to a room temperature, carbon acid
gas contained in air is solved in this water to become neutral.
However, if this water is warmed, then carbon acid gas is not
solved in this warmed water, but may easily represent alkaline.
[0043] Also, in accordance with the investigation made by the
Inventors, as to a color organic EL display, in such a case that a
soda glass substrate is employed as the substrate and the gas
barrier layer is formed on this soda glass substrate by a
low-temperature atomic layer forming method, when the soda glass
substrate is cleaned and thermally treated, and also, electrodes
are formed after the step for forming the gas barrier layer, such a
fact can be revealed. That is, a foaming/peeling phenomenon may
occur between the gas barrier layer and the soda glass
substrate.
[0044] Under such a circumstance, the Inventors have deeply
performed the investigations, and have improved the above-explained
respective means, and therefore, could conceive the below-mentioned
means in order prevent the following problems. That is, the gas
barrier layer is damaged by the medicines which are used in the
steps subsequent to the step for forming the gas barrier layer, and
the gas barrier layer is peeled with respect to the soda glass
substrate.
First Embodiment
[0045] FIG. 1 is a diagram for indicating a substantially sectional
structure of a color organic EL display 100 according to a first
embodiment mode of the present invention. FIG. 2 is a diagram for
showing a substantially sectional structure of the color organic EL
display 100, taken along a dot and dash line II-II shown in FIG.
1.
[0046] [Structure]
[0047] A substrate 11 is made of a glass substrate, a substrate
made of a resin (resin substrate), or the like. In this color
organic EL display 100 of the first embodiment mode, the substrate
11 corresponds to a transparent substrate 11 which is made of a
glass substrate.
[0048] Red, blue, and green color filter layers 13 which correspond
to three primary colors of light have been provided on one plane of
this glass substrate 11. It should be noted that shadow masks
(black matrix) 12 used to separate the color filter layers 13 have
been formed on one plane of the substrate 11, and the color filter
layers 13 have been provided with the shadow masks 12. The shadow
masks 12 are employed so as to cut off light, and are made of a
resin, or a metal. The shadow masks 12 may be provided, if
necessary.
[0049] A transparent overcoat layer 14 has been formed over the
color filter layers 13 and the shadow mask 12 as a flattening
layer, if required. It should also be noted that if this overcoat
layer 14 may be omitted, then this overcoat layer 14 need not be
employed. The color filter layers 13 and the overcoat layer 14 have
been mainly formed by an acrylic-series resin. Then, a gas barrier
layer 20 has been formed on this overcoat layer 14 in such a manner
that the gas barrier layer 20 covers this overcoat layer 14.
[0050] A degassing process operation has been carried out with
respect to underlayer portions of the gas barrier layer 20, namely,
the substrate 10, the color filter layers 13, and the overcoat
layer 14. Concretely speaking, the substrate 11 where the various
layers up to the overcoat layer 14 have been formed is put into
either a thermostatic oven or a vacuum chamber, and then, a
degassing process operation and a dehydrating process operation are
performed with respect to the conducted substrate 11.
[0051] It is preferable that a temperature of this degassing
process operation is selected to be higher than, or equal to such a
temperature which is applied to the substrate 11 in a manufacturing
step after the above-described degassing process step, and lower
than, or equal to a decomposition starting temperature of the color
filter layers 13. For example, in this first embodiment mode, the
degassing process temperature may be preferably selected to be
200.degree. C. to 230.degree. C.
[0052] The gas barrier layer 20 has been manufactured by executing
an atomic layer growing method at a temperature lower than, or
equal to the decomposition starting temperature of the color filter
layers 13 and the overcoat layer 14. This atomic layer growing
method is referred to as either an "atomic layer epitaxy method
(ALE method)" or an "atomic layer deposition method (ALD
method)."
[0053] In this case, the decomposition starting temperature of the
color filter layers 13 and the overcoat layer 14 is approximately
230.degree. C. Also, the gas barrier layer 20 may be formed as an
inorganic film which is made of one, or more sorts of metals. The
metals are selected from Al.sub.2O.sub.3, TiO.sub.2, SiN,
SiO.sub.2, SiON, ZrO.sub.2, MgO, GeO.sub.2, CaO, HfO.sub.2, and
ZnO.
[0054] Also, a film thickness of the gas barrier layer 20 may be
selected to be smaller than, or equal to 100 nm, preferably smaller
than, or equal to 60 nm. In this first embodiment mode, the gas
barrier layer 20 is such an alumina (Al.sub.2O.sub.3) film which
has been formed with a thickness of approximately 60 nm.
[0055] In the atomic layer growing method which is used in this
first embodiment mode, trimetyle aluminium corresponding to an
organic metal was used as a material in order that the gas barrier
layer 20 can be formed at a relatively low temperature at which no
damage is given to both the color filter layers 13 and the overcoat
layer 14. That is, to form the organic metal at a temperature lower
than, or equal to the decomposition starting temperature of the
color filter layer 13 and the overcoat layer 14, the trimetyle
aluminum is used.
[0056] A film forming temperature of the gas barrier layer 20 may
be selected to be on the order of 100 to 250.degree. C. This film
forming temperature is determined by considering such a condition
that the film forming temperature is selected to be lower than, or
equal to the decomposition starting temperature of both the color
filter layers 13 and the overcoat layer 14, and further, is
selected to be higher than, or equal to a temperature applied to
the substrate 11 in forming steps subsequent to the step for
forming the gas barrier layer 20. Preferably, this film forming
temperature of the gas barrier layer 20 may be selected to be
200.degree. C. to 230.degree. C. in this first embodiment mode.
[0057] Then, an organic EL structural body 30 functioning as an
organic electronic device has been formed over one plane of the
substrate 11, namely on the gas barrier layer 20. In other words,
the color organic EL display 100 has been formed in such a manner
that while one plane of the substrate 11 where the organic EL
structural body 30 is formed has been covered by the gas barrier
layer 20, the organic EL structural body 30 has been formed over
both this substrate 11 and the gas barrier layer 20.
[0058] This organic EL structural body 30 corresponds to such a
structural body manufactured by arranging an organic layer 32
containing an organic light emitting material between one pair of
electrodes 31 and 33, while one pair of these electrodes 31 and 33
are located opposite to each other. As this organic EL structural
body 30, materials and film structures may be employed which are
employed in a normal organic EL structural body. One example of
concrete structures will now be explained.
[0059] First, an anode (lower electrode) 31 functioning as a
transparent conducting film has been formed on the gas barrier
layer 20. The anode 31 is made of such a transparent conducting
film as an ITO (indium tin oxide), and may function as a hole
injection electrode.
[0060] The anode 31 has been formed by patterning an ITO film (for
example, thickness is 150 nm) by way of an etching process in a
stripe shape which is extended along right/left directions in FIG.
1. This ITO film has been formed by way of a sputtering method on
the gas barrier layer 20 at a film forming temperature of
200.degree. C.
[0061] As one example of this stripe shape, a plurality of
band-shaped anodes 31 each having a width of 500 .mu.m may be
arranged in a stripe shape in an interval of 50 .mu.m.
[0062] Further, an insulating film 40 made of an insulating
material is formed by performing a photolithography method in order
to prevent short-circuit occurred at an edge of the anode 31.
Similarly, a partition wall 41 is formed so as to separate a
cathode (upper electrode) 33 by the photolithography.
[0063] A hole injection layer, a hole transport layer, a light
emitting layer, and an electron transport layer are sequentially
formed as the organic layer 32 on this anode 31. These layers are
made of an organic light emitting material.
[0064] For instance, copper phthalic cyanin is formed as the hole
injection layer having a thickness of 20 nm by performing a vacuum
vapor deposition method. On this hole injection layer,
triphenylamine tetramer (HOMO: 5.4 eV, LUMO: 2.4 eV, Eg: 3.0 eV) is
formed as the hole transport layer having a thickness of, for
example, 40 nm by executing a vacuum vapor deposition manner.
[0065] Furthermore, as a red light emitting layer having a
thickness of, for example, 2 nm, triphenylamine tetramer into which
DCJT (HOMO: 5.3 eV, LUMO: 3.2 eV, Eg: 2.1 eV) has been added by 1%
is formed by performing a vacuum vapor deposition method.
[0066] On this red light emitting layer, BAlq (HOMO: 5.8 eV, LUMO:
3.0 eV, Eg: 2.8 eV) into which perylene (HOMO: 5.5 eV, LUMO: 2.6
eV, Eg: 2.9 eV) has been added by 1% by weight is formed by way of
a vacuum vapor deposition method. This perylene is used as
fluorescent dye functioning as a blue light emitting layer having a
thickness of, for example, 40 nm. In addition, aluminum complex
compound is formed at a thickness of 20 nm as the electron
transport layer by way of the vacuum vapor deposition method.
[0067] Although not shown in this drawing, a film having a
thickness of, for example, 0.5 nm of LiF has been formed as the
electron injection layer on these organic layers 32 by way of a
vacuum vapor deposition method. On this electron injection layer, a
film having a thickness of, for example, 100 nm of Al (aluminum)
has been formed as the cathode 33 corresponding to the upper
electrode by way of a vacuum vapor deposition method. In this case,
the cathode 33 has been formed in a stripe shape which is
orthogonally intersected with the anode 31 in such a manner that
the stripe shape of this cathode 33 is extended along the
right/left directions in FIG. 2.
[0068] Then, the organic EL structural body 30 (containing the
anode 31, the organic layer 32, and the cathode 33) which emits
white light has been formed by using these layers. It should also
be noted that film forming temperatures at which the organic layer
32 and the cathode 33 are formed by way of the vacuum vapor
deposition method are selected to be approximately the room
temperature.
[0069] As previously explained, the organic EL structural body 30
of this first embodiment mode has been manufactured as follows:
That is, the anode 31 having the stripe shape is overlapped with
the cathode 33 which is separated from the anode 31 by the
partition wall 41 in such a manner that the anode 31 is
orthogonally intersected with the cathode 33, and such a region
where these anode 31 and cathode 33 are overlapped with each other
constitutes display pixels (namely, original light emitting region)
which corresponds to such a portion where a light emitting display
should be carried out. Then, the color organic EL display 100
according to this first embodiment mode constitutes a dot matrix
display.
[0070] In this color organic EL display 100, since a driving DC
voltage having a predetermined duty ratio is applied between the
anode 31 and the cathode 33 by employing an external circuit, or
the like, holes are transported from the anode 31 and electrons are
transported from the cathode 33 into the light emitting layer
contained in the organic layer 32 respectively in desirable display
pixels.
[0071] Then, these holes are recombined with these electrons within
this light emitting layer, so that the fluorescent material
(namely, DCJT, perylene, and Balq in this first embodiment mode)
emits light by the radiation energy thereof. This light emission is
derived from the substrate 11 via the color filter layers 13.
[0072] [Manufactoring Method]
[0073] Next, a method for manufacturing the color organic EL
display 100 according to the first embodiment mode will now be
described, although a slightly duplicated explanation is made.
[0074] Both the color filter layers 13 and the overcoat layer 14
are sequentially formed on one plane of the substrate 10 by way of
either a spin coating method or a photolithography method. The
underlayer portion of the gas barrier layer 20 can be accomplished
by executing the previous manufacturing steps. Also, the
decomposition starting temperature of the color filter layers 13
and the overcoat layer 14 is selected to be 230.degree. C.
[0075] Next, a degassing process operation is carried out with
respect to the underlayer portion of the gas barrier layer 20. It
is preferable that a temperature of this degassing process
operation is selected to be higher than, or equal to such a
temperature which is given to the substrate 11 in a manufacturing
step after the above-described degassing process step, and lower
than, or equal to a decomposition starting temperature of the color
filter layers 13. For example, in this first manufacturing step,
the degassing process temperature may be preferably selected to be
200.degree. C. to 230.degree. C.
[0076] Also, it is preferable that the degassing process step is
carried out in a dry atmosphere. Concretely speaking, the substrate
11 on which the various layers up to the, overcoat layer 14 have
been formed is put into either the thermostatic oven or the vacuum
chamber so as to sinter this conducted substrate 11 in such a dry
atmosphere as a vacuum atmosphere, and a dry nitrogen gas
atmosphere. Then, the degassing process operation and the
dehydrating process operation are carried out.
[0077] Next, forming of the gas barrier layer 20 is performed. In
this forming step, it is preferable to hold the substrate 11 within
the dry atmosphere in a consistent manner after the degassing
process step until a forming step of the gas barrier layer 20.
[0078] Concretely speaking, after the substrate 11 has been set to
a film forming apparatus for forming the gas barrier layer 20, a
vacuum heating operation is sufficiently carried out so as to
execute a dehydrating process operation as to water contents.
Thereafter, the gas barrier layer 20 is formed by performing an
atomic layer growing method.
[0079] Alternatively, after the substrate 11 has been sufficiently
heated in a dry atmosphere such as a vacuum atmosphere, or a
nitrogen atmosphere in a multi-chamber apparatus in which a chamber
for a dehydrating process step has been provided, the substrate 11
may be moved to another chamber for forming the gas barrier layer
20 by way of an atomic layer growing method so as to form this gas
barrier layer 20.
[0080] Then, in the forming step of the gas barrier layer 20, this
gas barrier layer 20 is formed by executing such an atomic layer
growing method that material gases are alternately supplied so as
to form a thin film under reduced pressure at such a temperature
which is lower than, or equal to the decomposition starting
temperature of the color filter layers 13.
[0081] While the overcoat layer 14 made of the organic material has
been interposed between the color filter layers 13 and the gas
barrier layer 20, this gas barrier layer 20 is formed at a
temperature lower than, or equal to the decomposition starting
temperature of both the color filter layers 13 and the overcoat
layer 14.
[0082] Also, it is preferable to set a film forming temperature of
the atomic layer growing method for forming this gas barrier layer
20 to be higher than, or equal to such a temperature applied to the
substrate 11 in the forming step subsequent to the forming step of
the gas barrier layer 20, namely in the step for forming the
organic EL structural body 30.
[0083] Such a film forming temperature of the gas barrier layer 20
may be selected to be on the order of 100 to 250.degree. C. In this
manufacturing method, this film forming temperature is determined
by considering such a condition that the film forming temperature
is selected to be lower than, or equal to the decomposition
starting temperature of both the color filter layers 13 and the
overcoat layer 14, and further, is selected to be higher than, or
equal to the temperature applied to the substrate 11 in forming
steps subsequent to the step for forming the gas barrier layer 20.
Preferably, this film forming temperature of the gas barrier layer
20 may be selected to be 200.degree. C. to 230.degree. C. in this
first embodiment mode.
[0084] The gas barrier layer 20 is made of alumina by way of an
atomic layer growing method. The formation of such a gas barrier
layer 20 is carried out as follows: That is, the substrate 11 which
has been treated by a degassing process operation and a dehydrating
process operation is conducted to a reaction furnace; this reaction
furnace is set in a vacuum atmosphere; and then, both vaporized TMA
(trimethyl aluminium) and vaporized H.sub.2O are alternately
conducted to the reaction furnace by a carrier gas such as an
N.sub.2 gas. As to this detailed forming method, since a film
forming method of a general atomic layer forming method may be
employed which has been conventionally carried out, the explanation
thereof is omitted.
[0085] Next, the organic EL structural body 30 is formed on one
plane of the substrate 11, namely on the gas barrier layer 20.
[0086] In this first manufacturing method, an ITO film (having
thickness of, for example, 150 nm) is patterned by executing an
etching process operation so as to form the anode (lower electrode)
31 as the transparent conducting film. This ITO film has been
formed on the gas barrier layer 20 by executing a sputtering method
at the film forming temperature of 200.degree. C.
[0087] The maximum temperature applied to the substrate 11 in a
step subsequent to the degassing process step is preferably
selected to be the film forming temperature of this anode 31,
namely 200.degree. C., and the above-explained degassing process
step is preferably carried out at a temperature higher than, or
equal to the above-explained film forming temperature of
200.degree. C.
[0088] Next, the insulating film 40 is formed on the anode 31 by
way of a photolithography method, and subsequently, the partition
wall 41 is formed on the insulating film 40 by the
photolithography. Next, the organic layer 32 is formed on the anode
31 by way of a vacuum vapor deposition method, while the organic
layer 32 has been formed by sequentially forming thereon the hole
injection layer, the hole transport layer, the light emitting
layer, and the electron transport layer.
[0089] Next, both LiF functioning as the electron injection layer,
and the cathode 33 functioning as the upper electrode are formed in
the film form on the organic layer 32 by way of a vacuum vapor
deposition method. A film forming temperature of the organic layer
32 and the cathode 33 by way of the vacuum vapor deposition method
is selected to be the room temperature. As a result, the color
organic EL display 100 shown in FIG. 1 and FIG. 2 can be
accomplished in accordance with the first manufacturing method.
[0090] It should also be understood that after this color organic
EL device 100 has been manufactured, the-outer surface side of the
organic EL structural body 30 may be alternatively sealed by a
sealing can which is made of either stainless steel or glass and
contains a desiccating agent in order to cut off water contents
vaporized from the surface of this organic EL structural body 30,
while inert gas (N.sub.2 gas etc.) containing a very small amount
of oxygen, or only the inert gas is employed.
[0091] Also, as another sealing method, the outer surface of the
organic EL structural body 30 may be covered by such a protection
film which has been formed by way of an atomic layer growing
method, a sputtering method, a CVD method, a vapor deposition
method, or the like. As a result, the deteriorations of the organic
EL structural body 30 which are caused by water contents and/or gas
can be prevented in a higher level. In addition, if a protection
plate made of glass, a resin, a metal, or the like is adhered via
an adhesive agent such as a resin onto this protection film, then
there is a merit in view of avoiding a production of scratches.
[0092] [Effects]
[0093] As previously explained, in accordance with the first
embodiment mode, the color organic EL display 100 may be provided
with employment of the below-mentioned feature. That is, in the
color organic EL display 100 manufactured by that the color filter
layers 13, the gas barrier layer 20, and the organic EL structural
body 30 have been sequentially stacked on the substrate 11, the
underlayer portion of the gas barrier layer 20 has been treated by
the degassing process operation, and the gas barrier layer 20 has
been formed by way of the atomic layer growing method at the
temperature lower than, or equal to the decomposition starting
temperature of the color filter layer 13.
[0094] Since the underlayer portion of the gas barrier layer 20 has
been formed by executing the degassing process operation, the
amount of the gas produced from the substrate 11, the color filter
layers 13, and the like can be reduced to the extremely small
amount.
[0095] Also, the gas barrier layer 20 has been manufactured by
performing the atomic layer growing method at the temperature lower
than, or equal to the decomposition starting temperature of the
color filter layer 13. As a consequence, the gas barrier layer 20
can be properly formed without deteriorating the color filter
layers 13.
[0096] Then, when the gas barrier layer 20 is formed, the atomic
layer growing method is employed which can realize such a film
capable of having the superior covering characteristic for a film
forming member and also in which a total number of pin-holes can be
reduced as small as possible, as compared with the vacuum vapor
deposition method, the sputtering method, and the plasma CVD
method. As a result, such a gas barrier layer 20 can be realized in
which the step coverage thereof become superior, and a small number
of pin-holes are formed, as compared with the prior art.
[0097] As a consequence, since the gas barrier layer 20 owns the
superior covering characteristic and has substantially no pin-hole,
the gas such as very small amounts of water contents contained in
the color filter layer 13 and the overcoat layer 14 can be blocked
by the gas barrier layer 20, so that the gas is not penetrated into
the organic EL structural body 30. As a consequence, the
deteriorations of the organic EL structural body 30 which are
caused by this gas can be properly prevented.
[0098] The concrete effects of the gas barrier layer 20 formed in
accordance with this first embodiment mode could be confirmed based
upon the below-mentioned method. That is, while a gas barrier layer
was formed on a glass substrate where an ITO film having a
thickness of 150 nm was formed in such a square dimension of 100
mm.times.100 mm in such a manner that this gas barrier layer 20
covers the entire plane of the ITO film, this glass substrate was
dipped for 30 minutes in 50% aqua regia having a temperature of
50.degree. C., which is employed as an etching fluid of the ITO
film. In this case, places of pin-holes formed in the gas barrier
layer 20 may be readily detected, since the ITO film may be etched
and may become more conspicuous as ITO defects.
[0099] In order to detect the ITO defects, surface conditions of
the glass substrate before/after this glass substrate was dipped in
the aqua regia were measured by a defect inspecting apparatus
(i.e., KLA ACROTEC 6020). Then, both a place where a defect size
was increased, and a newly increased defect place were observed by
employing a microscope. Accordingly, a judgment was made as to
whether or not this observed defect portion corresponds to an ITO
defect of the gas barrier layer which is caused by a pin hole. FIG.
8 represents a result of this evaluation.
[0100] As the gas barrier layer, an Al.sub.2O.sub.3 film having a
thickness of 30 nm was formed by way of the ALE method as to a
sample No. 1 to a sample No. 5; an Al.sub.2O.sub.3 film having a
thickness of 60 nm was formed by way of the ALE method as to a
sample No. 6 to a sample No. 10; and an SiO.sub.2 film having a
thickness of 300 nm was formed by way of the sputtering method as
to a sample No. 11 to a sample NO. 15 as comparative examples.
[0101] An effect of the degassing process operation was confirmed
by performing a thermal desorption spectroscopy (TDS analysis). A
substrate in which both a color filter layer and an overcoat layer
have been formed on glass was cut in a square dimension of 10
mm.times.10 mm. Thereafter, three sorts of these cut substrates
having the square dimensions of 10 mm.times.10 mm were processed in
accordance with the below-mentioned three processing methods:
[0102] 1) A first cut substrate was processed by a degassing
process operation in a dry nitrogen atmosphere for 2 hours at a
temperature of 200.degree. C., and then, the degassing-processed
first cut substrate was transported within the dry nitrogen
atmosphere. In FIG. 3, IIIA represents a sample of this
treatment.
[0103] 2) A second cut substrate was processed by a similar
degassing process operation to the degassing process operation, and
then, the degassing-processed second cut substrate was transported
in an atmosphere. In FIG. 3, IIIB represents a sample of this
treatment.
[0104] 3) A third cut substrate was not processed by a degassing
process operation. In FIG. 3, IIIC represents a sample of this
treatment.
[0105] In the TDS analysis, while a temperature of the substrate
was changed from 50.degree. C. up to 200.degree. C., amounts of
projected gas whose molecular weight is in a range between 1 and
199 were measured. FIG. 3 shows pressure changes by the molecular
weight 18 (H.sub.2O) where the largest amount of gas detected in
this TDS analysis was detected.
[0106] As a consequence, as to such the sample IIIA which has been
processed by the degassing process and then transported in the dry
nitrogen atmosphere, there is substantially no pressure change. To
the contrary, as to such the sample IIIB or IIIC which has not yet
been processed by the degassing process, or has been transported in
the atmosphere, emissions of water contents could be clearly
confirmed.
[0107] As previously explained, the below-mentioned concrete
effects could be confirmed, since the underlayer portion of the gas
barrier layer 20 has been processed by the degassing process
operation, and the gas barrier layer 20 has been formed by
executing the atomic layer growing method at the temperature which
is lower than, or equal to the decomposition starting temperature
of the color filter layer 13.
[0108] Also, since the gas barrier layer 20 can be formed in a
single process operation, namely the atomic layer growing method,
productivity of this gas barrier layer 20 can be improved, and the
cost-up problem thereof can be suppressed.
[0109] As a consequence, in the color organic EL display 100
manufactured by interposing the gas barrier layer 20 between the
organic EL structural body 30 and the color filter layer 13, such a
low-cost gas barrier layer 20 having the superior gas barrier
characteristic can be realized.
[0110] By the way, since the gas barrier layer 20 has been formed
by way of the atomic layer forming method, this gas barrier layer
20 can be made dense with less of pin-holes, as compared with the
conventional gas barrier layer formed by executing the sputtering
method, or the P-CVD method.
[0111] However, if the gas barrier layer 20 having less of the
pin-holes is merely formed in the color organic EL display 100,
then the below-mentioned problem may occur.
[0112] In the conventional color organic EL display, the gas
barrier layer having the relatively deteriorated dense
characteristic has been formed with the large number of pin-holes,
as compared with the gas barrier layer 20 formed by way of the
atomic layer growing method. As a result, even if gas is produced
from the underlayer portion, this produced gas may pass through the
gas barrier layer 20.
[0113] However, since the gas barrier layer 20 formed by the atomic
layer growing method can be made dense with less of the pin-holes
in accordance with this first embodiment mode, the gas produced
from the underlayer portion can hardly pass through this gas
barrier layer 20. As a result, there are some risks that the gas
barrier layer 20 is expanded by the produced gas, and the expanded
layer portion may be peeled.
[0114] As to this risky point, the underlayer portion of this gas
barrier layer 20 has been formed by executing the degassing process
operation, and thus, the amount of gas which is produced from the
degassing-processed underlayer portion is suppressed as small as
possible. As a consequence, since such an expansion of the gas
barrier layer 20 caused by the gas can be prevented, there is no
problem.
[0115] In other words, since the gas barrier layer 20 is not simply
formed by performing the atomic layer growing method, but the
underlayer portion of this gas barrier layer 20 may be realized to
solve the problem, which is caused by the gas barrier layer 20 made
dense with less of the pin-holes.
[0116] In the color organic EL display 100 according to this first
embodiment mode, while the overcoat layer 14 made of the organic
material has been interposed between the color filter layers 13 and
the gas barrier layer 20, the gas barrier layer 20 has been formed
at the temperature lower than, or equal to the decomposition
starting temperature of the color filter layers 13 and the overcoat
layer 14.
[0117] As previously explained, in such a case that the overcoat
layer 14 made of the organic material has been interposed between
the color filter layers 13 and the gas barrier layer 20, if the gas
barrier layer 20 has been formed at the temperature lower than, or
equal to the decomposition starting temperature of the color filter
layers 13 and the overcoat layer 14, then the gas barrier layer 20
can be manufactured in a proper manner, while not only the color
filter layers 13, but also the overcoat layer 14 is not
deteriorated.
[0118] Also, in the color organic EL display 100 of this first
embodiment mode, the substrate 11 may be made of a glass substrate,
and preferably may be made of a resin substrate. Since the resin
substrate owns a better molding characteristic and is made in low
cost, as compared with those of the glass substrate, this resin
substrate may be preferably used.
[0119] Also, as to such a color organic EL display manufacturing
method in which the color filter layers 13, the gas barrier layer
20, and the organic EL structural body 30 have been sequentially
stacked on the substrate 11, the below-mentioned manufacturing
method may be provided in which after the underlayer portion of the
gas barrier layer 20 has been treated by the degassing process
operation, the gas barrier layer 20 is formed by performing the
atomic layer growing method at the temperature lower than, or equal
to the decomposition starting temperatures of the color filter
layer 13, in which the material gases are alternatively supplied
under reduced pressure so as to form the thin film.
[0120] The color organic EL display 100 having the feature point
can be manufactured in a proper manner. Then, the operation/effects
thereof are similar to those of the color organic EL display
100.
[0121] Also, in the method for manufacturing the color organic EL
device 100, in such a case that the color organic EL display 100 is
manufactured by interposing the overcoat layer 14 made of the
organic material between the color filter layers 13 and the gas
barrier layer 20, such a feature point is also made. That is, the
gas barrier layer 20 may be formed at the temperature lower than,
or equal to the decomposition starting temperature of the color
filter layers 13 and the overcoat layer 14.
[0122] Also, it is preferable that a temperature of this degassing
process operation is selected to be higher than, or equal to such a
temperature which is given to the substrate 11 in the manufacturing
step after the degassing process step, and lower than, or equal to
the decomposition starting temperature of the color filter layers
13.
[0123] If a temperature of a degassing process operation is lower
than such a temperature applied to the substrate 11 in a step
subsequent to this degassing process operation, there are some
possibilities that gas is further produced from the underlayer
portion of the gas barrier layer 20 in the step subsequent to the
degassing process operation.
[0124] As to this technical aspect, if this preferable
manufacturing method is employed, then such a problem may be
avoided, so that the production of the gas in the step subsequent
to the degassing processing step can be reduced. Furthermore, there
is no possibility that the color filter layers 13 are deteriorated
in the degassing process step.
[0125] Also, it is preferable that the degassing process step is
carried out in the dry atmosphere.
[0126] As a result, since an efficiency of the degassing process as
to the underlayer portion of the gas barrier layer 20 can be
improved, the degassing process operation is preferable.
[0127] Also, it is preferable to hold the substrate 11 in the
consistent manner within the dry atmosphere for process steps after
the degassing process step until the forming step of the gas
barrier layer 20.
[0128] This manufacturing method can preferably avoid that the gas
components are again attached to the underlayer portion of the gas
barrier layer 20 after the degassing process operation of this
underlayer portion of the gas barrier layer 20 has been carried out
until the step for forming the gas barrier layer 20.
[0129] Also, it is preferable that the film forming temperature of
the atomic layer growing method for forming the gas barrier layer
20 is higher than, or equal to the temperature applied to the
substrate 11 in the step subsequent to the step for forming the gas
barrier layer 20.
[0130] As a consequence, this manufacturing method may give a merit
that occurrences of cracks and peeling as to the gas barrier layer
20 can be suppressed in the step subsequent to the forming step of
the gas barrier layer 20.
[0131] The gas barrier layer 20 having preferable characteristics
is further described in view of protection of peeling off and
protection of generating cracks.
[0132] [Degassing Process]
[0133] In the color organic EL display 100, the degassing process
is performed in such a manner that the color filter layer 13 and
the overcoat layer 14 as the underlayer of the gas barrier layer 20
are annealed at 200.degree. C. in vacuum. In this case, it is
preferred that the number of degassed water molecules is equal to
or smaller than 2.times.10.sup.16 molecules per mm.sup.3. Here, the
degassed water molecules are discharged from the color filter layer
13 and the overcoat layer 14 at 200.degree. C. in vacuum.
[0134] In the gas barrier layer 20 having large density and no pin
holes formed by the ALE method, the underlayer of the gas barrier
layer 20 is degassed and the amount of the gas discharged from the
underlayer is limited so that the gas barrier layer 20 is prevented
from expanding according to the gas. Specifically, degree of the
degassing process is further studied. Here, the amount of the
degassed water is chosen as an index of the degree of the degassing
process. The degassed water is discharged from the color filter
layer 13 and the overcoat layer 14. The amount of the degassed
water is measured by the TDS analysis.
[0135] A glass substrate having a color filter layer and an
overcoat layer formed on the substrate is prepared. The substrate
has dimensions of 10 mm.times.10 mm. The substrate is degassed at
200.degree. C. in vacuum for 10 minutes, 20 minutes, 60 minutes or
120 minutes. Then, the substrate is transported in dry nitrogen
atmosphere. To compare with these substrates, a comparison sample
is prepared. The comparison sample is not processed in the
degassing process, i.e., the substrate is not degassed.
[0136] According to the TDS analysis, the substrate temperature is
changed from 50.degree. C. to 200.degree. C. Then, the amount of
the degassed water is calculated on the basis of integrated value
of degassed pressure of molecular weight of 18. The molecular
weight of 18 represents water, i.e., H.sub.2O. The result is shown
in FIG. 4. FIG. 4 shows a relationship between the process time of
the degassing process and the amount of the degassed water. In FIG.
4, the process time represents as "a baking time at 200.degree. C.
(scale on the minute)," which provides the horizontal axis. The
amount of the degassed water represents as "the number of water
molecules (scale on the molecules per mm.sup.3)," which provides
the vertical axis.
[0137] In FIG. 4, as the process time increases, the amount of the
degassed water is reduced. And, in a case where the process time is
about 60 minutes, the amount of the degassed water is saturated so
that the amount of the degassed water becomes around
2.times.10.sup.16 molecules per mm.sup.3. Thus, when the substrate
is degassed at 200.degree. C. in vacuum for equal to or longer than
60 minutes, the water contained in the color filter layer and the
overcoat layer can be removed sufficiently.
[0138] Next, the Al.sub.2O.sub.3 film as the gas barrier layer is
deposited on the above five different types of substrates after
degassing process, respectively. Specifically, the gas barrier
layer is formed on the color filter layer and the overcoat layer by
the ALE method. Then, peeling off test is performed after the
degassing process. The result is shown in FIG. 9. The color filter
layer 13 and the overcoat layer 14 as the underlayer of the gas
barrier layer 20 are degassed at 200.degree. C. in vacuum. Further,
when the number of the degassed water molecules discharged from the
color filter layer 13 and the overcoat layer 14 is equal to or
smaller than 2.times.10.sup.16 molecules per mm.sup.3, the peeling
off of the gas barrier layer 20 is prevented. Specifically, when
the process time is equal to or longer than 60 minutes, the peeling
off of the gas barrier layer 20 is prevented.
[0139] [Stress in Gas Barrier Layer]
[0140] In the color organic EL display 100, to prevent cracks in
the gas barrier layer 20, the stress in the gas barrier layer is
reduced. Specifically, the total stress in the gas barrier layer 20
is preferably reduced less than the limited stress of cracks.
[0141] This total stress depends on the membrane stress of the
material of the gas barrier layer 20 and the thickness of the gas
barrier layer 20. Therefore, reducing the thickness of the gas
barrier layer 20 is effective for reducing the total stress. Thus,
the thickness of the gas barrier layer 20 is determined in view of
the total stress. According to the Inventors, the single layer of
the Al.sub.2O.sub.3 film and the single layer of the TiO.sub.2 film
have no thickness dependency of the membrane stress. Specifically,
the membrane stress in the Al.sub.2O.sub.3 film is 300 MM/m.sup.2,
and the membrane stress in the TiO.sub.2 film is 1400
MN/m.sup.2.
[0142] FIG. 5 shows a relationship between the total stress and the
film thickness in the gas barrier layer 20. In FIG. 5,
"Al.sub.2O.sub.3=30" represents a case where the gas barrier layer
20 is made of the single layer of the Al.sub.2O.sub.3 film, and the
film thickness of the Al.sub.2O.sub.3 film is 30 nm.
"TiO.sub.2/Al.sub.2O.sub.3=9/30" represents a case where the gas
barrier layer 20 is made of the multi-layered film of the
Al.sub.2O.sub.3 film and the TiO.sub.2 film, and the total film
thickness X of the Al.sub.2O.sub.3 film is 30 nm and the total film
thickness Y of the TiO.sub.2 film is 9 nm. Here, the multi-layered
film of the Al.sub.2O.sub.3 film and the TiO.sub.2 film can be
formed of a two-layer film, in which the Al.sub.2O.sub.3 film and
the TiO.sub.2 film are deposited by the atomic layer deposition
method, respectively. Further, the multi-layered film of the
Al.sub.2O.sub.3 film and the TiO.sub.2 film can be formed of an
alternate stacking film, in which the Al.sub.2O.sub.3 films and the
TiO.sub.2 films are multiply, repeatedly and alternately stacked
each other.
[0143] The total stress of the multi-layered film of the
Al.sub.2O.sub.3 film and the TiO.sub.2 film shown in FIG. 5
corresponds to the total stress estimated from the membrane stress
of the single layer of the Al.sub.2O.sub.3 film, the membrane
stress of the single layer of the TiO.sub.2 film, and the ratio of
thickness of the Al.sub.2O.sub.3 film and the TiO.sub.2 film.
[0144] Next, cracks in the gas barrier layer 20 after deposition is
observed. FIG. 10 shows the results of the observation of the
cracks in the single layer of the Al.sub.2O.sub.3 film and in the
multi-layered film of the Al.sub.2O.sub.3 film and the TiO.sub.2
film as the gas barrier layer 20.
[0145] As shown in FIG. 10, when the gas barrier layer 20 made of
the single layer of the Al.sub.2O.sub.3 film, the cracks generate
in the gas barrier layer 20 in a case where the film thickness of
the gas barrier layer 20 is equal to or thicker than 120 nm. Thus,
it is preferred that the film thickness of the single layer of the
Al.sub.2O.sub.3 film as the gas barrier layer 20 is equal to or
thinner than 100 nm. In this case, the total stress in the gas
barrier layer 20 is about 37 N/m. Therefore, when the total stress
is almost equal to or smaller than 37 N/m, no crack generates in
the gas barrier layer 20.
[0146] Regarding the multi-layered film of the Al.sub.2O.sub.3 film
and the TiO.sub.2 film, the total stress of the gas barrier layer
20 is designed to be equal to or smaller than 37 N/m so that no
crack is generated in the gas barrier layer 20. Specifically, the
total stress of the multi-layered film is calculated from the
results shown in FIG. 5. Specifically, when the gas barrier layer
20 is formed of the multi-layered film of the Al.sub.2O.sub.3 film
and the TiO.sub.2 film, the total thickness X (scale on the meter,
i.e., m) of the Al.sub.2O.sub.3 film in the multi-layered film and
the total thickness Y (scale on the meter, i.e., m) of the
TiO.sub.2 film in the multi-layered film satisfy the relationship
of:
37.gtoreq.3.times.10.sup.8.times.X+1.4.times.10.sup.9.times.Y.
[0147] In this case, the total stress in the gas barrier layer 20
made of the multi-layered film becomes smaller than the stress
limit of cracks so that the cracks in the gas barrier layer 20 is
prevented.
[0148] [Adhesiveness of Gas Barrier Layer]
[0149] In the color organic EL display 100, it is preferred that a
contact angle of the surface of the underlayer of the gas barrier
layer 20 is equal to or smaller than 10 degrees.
[0150] In a mounting step of the color organic EL display 100, the
mounting is performed by thermal press contact method by using
anisotropic conductive bonding film (i.e., ACF). To prevent the gas
barrier layer 20 from peeling off in the mounting process, the
surface of the substrate 11 is cleaned up so that an absorption
site, i.e., hydroxyl group, is stabilized. To clean the surface of
the substrate 11, a UV process of the surface of the substrate is
effective. The UV process is such that the surface of the substrate
11 is irradiated with ultra violet light.
[0151] Here, the contact angle of the substrate 11 having the color
filter layer 13 is studied under different cleaning conditions.
FIG. 11 shows the results of the contact angle test. The contact
angle of the substrate 11 is measured by dropping a water drop on
the surface of the substrate 11. FIG. 11 shows the contact angle
before and after cleaning. That is, the initial contact angle of
the substrate 11 and the after cleaning contact angle of the
substrate 11 are measured. Here, this contact angle is measured
twice, i.e., n=2. Therefore, the average change of the contact
angle is obtained. The change of the contact angle is obtained by
subtracting the after cleaning contact angle from the initial
contact angle.
[0152] In the cleaning condition in FIG. 11, WET represents the
substrate 11, which is cleaned by a wet washing method only. Wet+UV
represents the substrate 11, which is cleaned by the wet washing
method, dried with an ordinary drying method, and then, cleaned by
a UV ozone washing method. WET+IR+UV represents the substrate 11,
which is cleaned by the wet washing method, dried with an infra red
light heating and drying method, and then, cleaned by a UV ozone
washing method.
[0153] As shown in FIG. 11, the initial contact angle of the
substrate 11 is in a range between 40 degrees and 60 degrees. Thus,
variations of the initial contact angle are large. However, after
the substrate 11 is cleaned by the UV ozone washing method, the
after cleaning contact angle becomes almost equal to or smaller
than 10 degrees.
[0154] Then, the substrates 11 cleaned by different cleaning
conditions, i.e., WET, WET+UV, and WET+IR+UV conditions are further
studied. Specifically, the Al.sub.2O.sub.3 film as the gas barrier
layer 20 having the thickness of 30 nm is formed on the substrates
11 by the ALD method, respectively. Then, an ACF (i.e., anisotropic
conductive film) contact test is performed.
[0155] FIG. 12 shows the results of the ACF contact test. The test
is performed in different mounting conditions. Then, peeling off of
the gas barrier layer 20 is checked. Three mounting conditions are
tested. One is such that the mounting is performed at 280.degree.
C. under pressure of 1.5 MPa, second is such that the mounting is
performed at 310.degree. C. under pressure of 4 MPa, and third is
such that the mounting is performed at 330.degree. C. under
pressure of 4 MPa.
[0156] As shown in FIG. 12, in the substrate 11 performed by the UV
process, the gas barrier layer 20 is protected from peeling off.
However, in the substrate 11 not performed by the UV process, the
gas barrier layer 20 peels off.
[0157] Specifically, to prevent the gas barrier layer 20 from
peeling off in a case where the substrate 11 is performed only by
the wet washing method, it is required to set the adhesive pressure
of the ACF equal to or smaller than 1 MPa. However, in this case
where the adhesive pressure is equal to or smaller than 1 MPa, the
conductivity of the ACF connection is not secured.
[0158] Thus, the contact angle on the surface of the substrate 11
is set to be equal to or smaller than 10 degrees. Further, the
adhesiveness of the gas barrier layer 20 formed on the surface of
the substrate 11 is sufficiently secured. Specifically, in this
case, the gas barrier layer 20 is protected from peeling off. Here,
the peeling off of the gas barrier layer 20 is generally occurred
by heat, pressure or thermal expansion when the ACF is connected to
the display.
Second Embodiment
[0159] FIG. 4 is a diagram for indicating a substantially sectional
structure of a color organic EL display 200 according to a second
embodiment mode of the present invention.
[0160] In this color organic EL display 200, in such a case that
the anode 31 has been formed on the gas barrier layer 20 and
functions as a transparent conducting film which constitutes the
organic EL structural body 30, it is preferable that an SiO.sub.2
layer 50 capable of improving a close contacting characteristic
between these gas barrier layer 20 and transparent conducting film
31 is interposed between the gas barrier layer 20 and the
transparent conducting film 31.
[0161] This SiO.sub.2 layer 50 may be formed by performing a
sputtering method, or the like, and a film thickness thereof may be
selected to be, for example, approximately 20 nm. Since the close
contacting characteristic between the gas barrier layer 20 and the
transparent conducting film 31 can be improved by this SiO.sub.2
layer 50, there is a merit that the transparent conducting film 31
is patterned.
Third Embodiment
[0162] FIG. 5 is a diagram for indicating a substantially sectional
structure of a color organic EL display 300 functioning as an
organic electronic device element according to a third embodiment
mode of the present invention.
[0163] Also, the substrate 11 is constituted by a glass substrate,
a substrate made of a resin (namely, resin substrate), or the like.
The substrate 11 corresponds to such a transparent substrate 11
which is made of non-alkali glass and does not contain such an
alkaline component as potassium and sodium.
[0164] Similar to the above-explained embodiment mode, the shadow
mask (black matrix) 12 and the color filter layers 13 have been
formed on one plane of this substrate 11, on which the transparent
overcoat layer 14 has been formed as a fattening layer.
[0165] Then, the gas barrier layer 20 has been formed on the
overcoat layer 14 in such a manner that this gas barrier layer 20
covers the overcoat layer 14 by executing an atomic layer growing
method at a temperature lower than, or equal to a decomposition
starting temperature of the color filter layer 13 and the overcoat
layer 14.
[0166] Also, an underlayer portion of the gas barrier layer 20,
namely, the substrate 11, the color filter layers 13, and the
overcoat layer 14 have been processed by a degassing process
operation similar to the above-explained embodiment mode.
[0167] Then, a preferable temperature of this degassing process
operation is selected to be higher than, or equal to such a
temperature which is applied to the substrate 11 in a manufacturing
step after the degassing process step, and lower than, or equal to
a decomposition starting temperature of the color filter layers 13.
For example, the degassing process temperature may be preferably
selected to be 200.degree. C. to 230.degree. C.
[0168] In this case, the gas barrier layer 20 is manufactured by
sequentially stacking a first film 21 and a second film 22. The
first film 21 functions as a gas interrupting layer which
interrupts gasses produced from the underlayer portion of this gas
barrier layer 20. The second film 22 functions as a step
withstanding layer having a withstanding characteristic with
respect to medicines used in steps subsequent to the step for
forming the gas barrier layer 20.
[0169] In this case, the first film 21 functioning as the gas
interrupting layer in the gas barrier layer 20 may be formed as an
inorganic film which is made of one, or more sorts of metals. The
metals are selected from Al.sub.2O.sub.3, TiO.sub.2, SiN,
SiO.sub.2, SiON, ZrO.sub.2, MgO, GeO.sub.2, CaO, HfO.sub.2, and
ZnO.
[0170] Also, a film thickness of the first film 21 may be selected
to be smaller than, or equal to 100 nm, preferably smaller than, or
equal to 60 nm. The first film 21 is such an alumina
(Al.sub.2O.sub.3) film which has been formed with a thickness of
approximately 60 nm.
[0171] In the atomic layer growing method which is used to form
this first film 21, trimetyle aluminum corresponding to an organic
metal was used as a material of the first film 21 in order that the
gas barrier layer 20 can be formed at a relatively low temperature
at which no damage is given to both the color filter layers 13 and
the overcoat layer 14, that is, at a temperature lower than, or
equal to the decomposition starting temperature of the color filter
layer 13 and the overcoat layer 14.
[0172] In this third embodiment mode, a film forming temperature of
the first film 21 may be selected to be on the order of 100 to
250.degree. C. This film forming temperature is determined by
considering such a condition that the film forming temperature is
selected to be lower than, or equal to the decomposition starting
temperature of both the color filter layers 13 and the overcoat
layer 14, and further, is selected to be higher than, or equal to a
temperature applied to the substrate 11 in forming steps subsequent
to the step for forming the gas barrier layer 20. Preferably, this
film forming temperature of the first film 21 may be selected to be
200.degree. C. to 230.degree. C.
[0173] Also, the second film 22 functioning as the step
withstanding layer in the gas barrier layer 20 is made of such a
material. That is, this material is combined with a hydroxyl group
(namely, OH group), so that a stable hydroxide can be hardly
formed. This second film 22 may be formed as an inorganic film
which is made of one, or more sorts of metals. The metals are
selected from TiO.sub.2, SiN, SiO.sub.2, SiON, and
Ta.sub.2O.sub.5.
[0174] Also, a film thickness of the second film 22 in the gas
barrier layer 20 may be selected to be preferably larger than, or
equal to 5 nm. The second film 22 is such a titania (TiO.sub.2)
film which has been formed with a thickness of approximately 5
nm.
[0175] In the atomic layer growing method which is used to form the
second film 22 as this step withstanding layer,
tetraisoproxytitanium corresponding to an organic metal was used as
a material of the second film 22 in order that the gas barrier
layer 20 can be formed at a relatively low temperature at which no
damage is given to both the color filter layers 13 and the overcoat
layer 14, that is, at a temperature lower than, or equal to the
decomposition starting temperature of the color filter layer 13 and
the overcoat layer 14.
[0176] It should be understood that titanium tetrachloride may be
alternatively employed other than tetraisoproxytitanium as the
material of the second film 22. A film forming temperature of this
second film 22 may be preferably selected to be approximately 100
to 250.degree. C.
[0177] Also, as shown in FIG. 3, in the color organic EL display
300, an insulating layer 23 having an electric insulating
characteristic has been interposed between the second film 22
provided in the gas barrier layer 20 and the organic EL structural
body 30.
[0178] When the second film 22 in the gas barrier layer 20 owns the
electric conducting characteristic, this insulating layer 23 is
provided. Since the second film 22 corresponds to the titania film
having the electric conducting characteristic, the insulating layer
23 has been provided. When the second film 22 corresponds to an
electric insulating film, this insulating layer 23 may be
omitted.
[0179] This insulating layer 23 may be made of one, or more sorts
of metals which are selected from SiN, SiO.sub.2, SiON,
Ta.sub.2O.sub.5, AlN, MgO, CaO, and GeO.sub.2. This insulating
layer 23 has been formed in a film having a thickness of 20 nm by
processing SiO.sub.2 by way of a sputtering method.
[0180] Then, the organic EL structural body 30 functioning as the
organic electronic device has been formed on one plane of the
substrate 11, namely on the gas barrier layer 20. In other words,
one plane of the substrate 11 where the organic EL structural body
30 will be formed has been covered by the insulating layer 23, and
both the first film 21 and the second film 22, which function as
the gas barrier layer 20. Then, the organic EL structural body 30
has been formed on this insulating layer 23.
[0181] Also, the organic EL structural body 30 functioning as the
organic electronic device corresponds to such a structural body
manufactured by arranging an organic layer 32 containing an organic
light emitting material between one pair of electrodes 31 and 33,
while one pair of these electrodes 31 and 33 are located opposite
to each other.
[0182] Then, as this organic EL structural body 30, materials and
film structures may be employed which are employed in a normal
organic EL structural body. One example of concrete structures may
be made similar to those of the first embodiment mode.
[0183] In other words, in the color organic EL display 300, a
stripe-shaped anode (lower electrode) 31 which is made of an ITO
film has been formed on the insulating layer 23. Also, both an
insulating film 40 and a partition wall 41 have been formed by
executing a photolithography method.
[0184] A hole injection layer, a hole transport layer, a light
emitting layer, and an electron transport layer have been
sequentially formed as an organic layer 32 formed on this anode 31.
These layers have been made of an organic light emitting
material.
[0185] Then, such a color organic EL display 300 has been
manufactured as a dot matrix display, while this dot matrix display
has been formed in such a way that the stripe-shaped cathode 33
made of Al is formed on the organic layer 32, and an area where the
anode 31 is overlapped with the cathode 33 is arranged as display
pixels.
[0186] The color organic EL display 300 may be basically
manufactured in a similar manner to that of the first embodiment
mode.
[0187] In this case, entire one plane as to the color filter layers
13 and the overcoat layer 14 has been covered by the insulating
layer 23 and the gas barrier layer 20 which is constituted by both
the first film 21 and the second film 22. After the underlayer
portion of the gas barrier layer 20 has been processed by executing
a degassing process operation in a similar manner to that of the
above-explained embodiment modes, the first film 21, the second
film 22, and the insulating layer 23 are formed.
[0188] For instance, the first film 21 made of alumina is formed by
way of an atomic layer growing method as follows: That is, the
substrate 11 which has been treated by a degassing process
operation and a dehydrating process operation is conducted to a
reaction furnace; this reaction furnace is set in a vacuum
atmoshpere; and then, both vaporized TMA (trimethyl aluminium) and
vaporized H.sub.2O are alternately conducted to the reaction
furnace by a carrier gas such as an N.sub.2 gas.
[0189] Also, the second film 22 made of titania may be formed by
way of the atomic layer growing method in a similar manner to that
of the first film 21 except that both tetraisoproxytitanium and
pure water are employed as a material.
[0190] It is preferable to set a film forming temperature of the
atomic layer growing method for forming the first film 22 and the
second film 22 to be higher than, or equal to such a temperature
applied to the substrate 11 in the forming step subsequent to the
forming step of the gas barrier layer 20, namely in the step for
forming the organic EL structural body 30. Such a film forming
temperature of the first film 21 and the second film 22 may be
selected to be on the order of 100 to 250.degree. C. Preferably,
this film forming temperature of these first and second films 21
and 22 may be selected to be 200.degree. C. to 230.degree. C.
similar to the first embodiment mode as to the film forming
temperature of the gas barrier layer 20 made of alumina.
[0191] It should also be noted that a detailed film forming
operation as to the first film 21 and the second film 22 by the
atomic layer growing method may be omitted, because the
general-purpose atomic layer growing method can be employed which
has been conventionally carried out.
[0192] On the other hand, the color organic EL display 300 may be
provided with employment of the below-mentioned feature. That is,
in the color organic EL display 300 manufactured by that the color
filter layers 13, the gas barrier layer 20, and the organic EL
structural body 30 have been sequentially stacked on the substrate
11, the underlayer portion of the gas barrier layer 20 has been
treated by the degassing process operation, and the gas barrier
layer 20 has been formed by way of the atomic layer growing method
at the temperature lower than, or equal to the decomposition
starting temperature of the color filter layers 13.
[0193] Since the underlayer portion of the gas barrier layer 20 has
been formed by executing the degassing process operation, the
amount of the gas produced from the underlayer portion of the gas
barrier layer 20 can be reduced to the extremely small amount.
Also, the gas barrier layer 20 having a superior step coverage and
less of pin-holes can be properly formed without deteriorating the
color filter layers 13.
[0194] As a consequence, similarly, in the color organic EL display
300, it is possible to properly avoid the deterioration of the
organic EL structural body 30, which is caused by the gas produced
from the underlayer portion of the gas barrier layer 20.
[0195] Further, the color organic EL display 300 is featured by
that the gas barrier layer 20 is manufactured by sequentially
stacking the first film 21 and the second film 22. The first film
21 functions as the gas interrupting layer which interrupts gasses
produced from the underlayer portion of this gas barrier layer 20.
The second film 22 functions as the step withstanding layer having
the withstanding characteristic with respect to medicines used in
the steps subsequent to the step for forming the gas barrier layer
20.
[0196] In accordance with this featured structure, the gas barrier
layer 20 can demonstrate the gas barrier characteristic by the
first film 21, and moreover, can own the withstanding
characteristic with respect to the medicines which are used in the
steps subsequent to the step for forming the gas barrier layer 20
based upon the second film 22. As a result, the gas barrier layer
20 can suppress the damages given to the gas barrier layer 20 as
being permitted as possible, which are caused by the medicines
which are used in the steps subsequent to the step for forming the
gas barrier layer 20.
[0197] Concrete effects as to the medicine withstanding
characteristic owned by the gas barrier layer 20 could be confirmed
in accordance with the below-mentioned methods.
[0198] That is, one gas barrier layer (will be referred to as
"sample No. 301") was manufactured in which an alumina film having
a thickness of 100 nm as the first film 21 was formed on silicon
substrate by performing the low temperature atomic layer growing
method. Further, another gas barrier layer (will be referred to as
"sample No. 302") was manufactured in which a titania film having a
thickness of 5 nm as the second film 22 was formed on the alumina
film by performing the low temperature atomic layer growing
method.
[0199] Then, both the sample No. 301 and the sample No. 302 were
dipped in warmed water of 70.degree. C., and thereafter, sectional
planes of these films were observed by using an electron
microscope.
[0200] As a result, the following conditions could be confirmed.
That is, in the sample No. 302 where the titania film has been
stacked on the alumina film, the film thicknesses as to both the
alumina film and the titania film were not changed, whereas in the
sample No. 1 having the single layer structure of the alumina film,
the film thickness of the alumina film was reduced, and the surface
of this alumina film became rough.
[0201] In other words, if the gas barrier layer 20 is manufactured
by the first film 21 functioning as the gas interrupting layer, and
the second film 22 which has been formed on the first film 21 as
the step withstanding layer, then both the first film 21 and the
second film 22 may have the superior covering characteristic and
own substantially no pin-hole. As a result, these films 21 and 22
can block very small amounts of water contents and of gasses, which
are contained in the color filter layers 13 and the overcoat layer
14, and further, can cause these water contents and gasses not to
be penetrated into the organic EL structural body 30.
[0202] Also, in the color organic EL display 300, since the
underlayer portion of the gas barrier layer 20 has been formed by
executing the degassing process operation, the amount of the gas
produced from the underlayer portion thereof can be reduced to the
extremely small amount, and similar to the first embodiment mode,
the expansion of the gas barrier layer 20 due to the produced gas
can be avoided.
[0203] As previously explained, the first film 21 in the gas
barrier layer 20, which is typically known as an amorphous alumina
film, may be very easily solved with respect to alkali and acid.
Especially, this first film 21 may be readily damaged with respect
to warmed water having a temperature higher than, or equal to
50.degree. C., an alkaline detergent, and an alkaline processing
fluid.
[0204] As to this damage aspect, the second film 22 in the gas
barrier layer 22 is made of such a material. That is, this material
is combined with a hydroxyl group, so that a stable hydroxide can
be hardly formed. For instance, this second film 22 is made of one,
or more sorts of metals. The metals are selected from TiO.sub.2,
SiN, SiO.sub.2, SiON, and Ta.sub.2O.sub.5. As a result, this second
film 22 can be hardly solved with respect to alkali and acid, and
thus, can properly represent the medicine withstanding
characteristic.
[0205] Also, in the color organic EL display 300, it is preferable
that the film thickness of the second film 22 formed in the gas
barrier layer 20 is thicker than, or equal to 5 nm. This preferable
film thickness could be confirmed in an experimental manner based
upon consideration made by the Inventors. As a consequence, if the
film thickness of this second film 22 is thicker than, or equal to
5 nm, then this second film 22 can properly represent the medicine
withstanding characteristic.
[0206] Further, in the color organic EL display 300, when the
second film 22 in the gas barrier layer 20 owns the electric
conducting characteristic, it is featured by that the insulating
layer 23 having the electric insulating characteristic has been
interposed between the second film 22 and the organic EL structure
body 30.
[0207] Normally, in the organic EL structural body 30 which is
formed on the gas barrier layer 20, the film which is located just
above the gas barrier layer 20 corresponds to the electrode film
having the electric conducting characteristic, namely the anode 31.
In such a case, if the second film 22 owns the electric conducting
characteristic, then the second film 22 may be electrically
conducted to the organic EL structural body 30, namely be
short-circuited.
[0208] As to this short-circuit aspect, since the layer located
just above the gas barrier layer 20 is formed as such an insulating
layer 23 having an electric insulating characteristic, it is
possible to prevent an occurrence of a short-circuit between the
gas barrier layer 20 and the organic EL structural body 30, for
example, if this insulating layer 23 may be made of one, or more
sorts of metals which are selected from SiN, SiO.sub.2, SiON,
Ta.sub.2O.sub.5, AlN, MgO, CaO, and GeO.sub.2.
[0209] Also, in accordance with the investigation made by the
Inventors, in such a case that a soda glass substrate is employed
as the substrate 11 in the color organic EL display, when the soda
glass substrate is cleaned and thermally treated, and also,
electrodes are formed after the step for forming the gas barrier
layer 20, such a fact can be revealed. That is, a foaming/peeling
phenomenon may occur between the gas barrier layer 20 and the soda
glass substrate 11.
[0210] To solve such a problem, the color organic EL display 300 is
featured by that the substrate 11 is made of non-alkali glass.
[0211] The Inventors analyzed the foaming/peeling phenomenon
occurred between the gas barrier layer 20 and the glass substrate
11. As a result of this analysis, the Inventors could recognize
that the alkaline components contained in the soda glass are
deposited, or separated due to heat which is produced when the
glass substrate 11 is cleaned and processed, and when the film is
formed, and thereafter, the deposited alkaline components may lower
the close contacting force between the gas barrier layer 20 and the
glass substrate 11.
[0212] As a consequence, if such a substrate is employed as this
substrate 11, which does not contain such alkaline components as
potassium and sodium, then it is possible to avoid peeling of the
gas barrier layer 20 in such a case that the soda glass substrate
is employed.
[0213] It should be noted that in order to solve the peeling
problem occurred between the substrate 11 and the gas barrier layer
20, another solution may be conceived by employing such a glass
substrate which is covered by an inorganic film containing no
alkaline component as the substrate 11.
[0214] As a result of this alternative solution, this inorganic
film may avoid that the alkaline components contained in the soda
glass are deposited, or separated due to heat which is produced
when the soda glass substrate is cleaned and processed, and when
the film is formed. As a result, similar to such a case that the
non-alkali glass is employed as the substrate 11, it is possible to
avoid peeling of the gas barrier layer 20 in such a case that the
soda glass substrate is employed.
[0215] In such a method for manufacturing the color organic EL
display 300 in such a manner that the color filter layers 13, the
gas barrier layer 20, and the organic EL structural body 30 are
sequentially stacked on the substrate 11, the following
manufacturing method is provided which is featured by that the
underlayer portion of the gas barrier layer 20 is treated by the
degassing process operation, and thereafter, the gas barrier layer
20 is formed by way of the atomic layer growing method at the
temperature lower than, or equal to the decomposition starting
temperature of the color filter layer 13, in which the material
gases are alternatively supplied under reduced pressure so as to
form the thin film.
[0216] The forming temperature of the gas barrier layer 20 may be
preferably selected to be lower than, or equal to the decomposition
starting temperature of both the color filter layers 13 and the
overcoat layer 14, and more preferably, may be selected to be
higher than, or equal to the temperature applied to the substrate
11 in forming steps subsequent to the step for forming the gas
barrier layer 20.
[0217] Also, in the manufacturing method, the temperature of the
degassing process operation may be preferably selected to be higher
than, or equal to the temperature applied to the substrate 11 in
the steps subsequent to this degassing process step, and
furthermore, may be preferably selected to be lower than, or equal
to the decomposition starting temperature of the color filter layer
13. Also, the preferable atmosphere of the degassing process step
corresponds to the dry atmosphere. Further, the substrate 11 may be
preferably held in the dry atmosphere in the consistent manner
after the degassing process step up to the step for forming the gas
barrier layer 20, which are similar to the manufacturing methods of
the above-explained embodiment modes.
[0218] Then, as a method for properly manufacturing the color
organic EL display 300 shown in FIG. 3, such a manufacturing method
may be provided that the gas barrier layer 20 is manufactured by
sequentially stacking the first film 21 and the second film 22,
while the first film 21 functions as the gas interrupting layer
which interrupts the gasses produced from the underlayer portion of
this gas barrier layer 20, and the second film 22 functions as the
step withstanding layer having the withstanding characteristic with
respect to the medicines used in steps subsequent to the step for
forming the gas barrier layer 20.
[0219] Also, the manufacturing method for the color organic EL
display 300 is featured by that the first film 21 in the gas
barrier layer 20 may be formed as an inorganic film which is made
of one, or more sorts of metals. The metals are selected from
Al.sub.2O.sub.3, TiO.sub.2, SiN, SiO.sub.2, SiON, ZrO.sub.2, MgO,
GeO.sub.2, CaO, HfO.sub.2, and ZnO.
[0220] Also, the manufacturing method for the color organic EL
display 300 is featured by that this second film 22 in the gas
barrier layer 20 may be formed as an inorganic film which is made
of one, or more sorts of metals. The metals are selected from
TiO.sub.2, SiN, SiO.sub.2, SiON, and Ta.sub.2O.sub.5. Furthermore,
in the manufacturing method for the color organic EL display 300,
the film forming temperature for forming the gas barrier layer 20
by way of the atomic layer growing method may be preferably
selected to be higher than, or equal to 200.degree. C.
[0221] As a result of investigations made by the Inventors, if the
film forming temperature for forming the gas barrier layer 20 by
way of the atomic layer growing method is selected to be higher
than, or equal to 200.degree. C., then the close contacting force
of the gas barrier layer 20 may be improved, and even when the soda
glass substrate is employed, peeling of the gas barrier layer 20
can be prevented.
Other Embodiments
[0222] It should also be understood that in accordance with the
color organic EL display of the present invention, at least, the
color filter layers, the gas barrier layer, and the organic EL
structural body have been simply stacked on the substrate in the
sequential manner. Alternatively, such a stacked layer structure
made of these structural elements may be provided, and also, the
overcoat layer and other layers may be furthermore interposed
between these structural elements.
[0223] Also, the structure of the organic EL structural body is not
limited only to the concrete example, but also may be realized by
employing materials and film structures which are employed in a
normal organic EL structural body, and may be alternatively
realized by employing materials and film structures which will be
employed in a future organic EL structural body.
[0224] A major portion of the present invention may be summarized
as follows: That is, in the color organic EL display manufactured
by that the color filter layers, the gas barrier layer, and the
organic EL structural body have been sequentially stacked on the
substrate, the underlayer portion of the gas barrier layer has been
treated by the degassing process operation, and the gas barrier
layer has been formed by way of the atomic layer growing method at
the temperature lower than, or equal to the decomposition starting
temperature of the color filter layer. Other structural portions
may be freely modified in a proper way.
[0225] While the invention has been described with reference to
preferred embodiments thereof, it is to be understood that the
invention is not limited to the preferred embodiments and
constructions. The invention is intended to cover various
modification and equivalent arrangements. In addition, while the
various combinations and configurations, which are preferred, other
combinations and configurations, including more, less or only a
single element, are also within the spirit and scope of the
invention.
* * * * *