U.S. patent application number 09/737656 was filed with the patent office on 2001-08-30 for production of structured electrodes.
Invention is credited to Gonther, Ewald.
Application Number | 20010017516 09/737656 |
Document ID | / |
Family ID | 7871319 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010017516 |
Kind Code |
A1 |
Gonther, Ewald |
August 30, 2001 |
Production of structured electrodes
Abstract
The present invention relates to a new method and apparatus for
structure electrodes of electro-luminescent components used
displays and the like. The electrodes are structured in such a way
that its layers are protected during structuring and the components
may be tightly packed together to improve display resolution. The
method includes the steps of: on a substrate (1) at least two
layers (3, 4) are applied, whereas the first layer (3) is
electrically insulated and is not damaged when the second layer (4)
is applied and between both layers a defined boundary is
maintained, and whereby the first layer shows a higher solvent rate
in a liquid solvent than the second layer and the second layer is
structurable and cross-linked; the second layer (4) is structured
and the structure is transferred onto the first layer (3) and then
the second layer (4) is cross-linked or the second layer (4) is
first structured and cross-linked and then the structure is
transferred onto the first layer (3), whereas the second layer
shows a larger structure width than the first layer and the
difference in the structure width of both layers is kept during the
cross-linking. On the second layer (4) the electrode (6) is
deposited.
Inventors: |
Gonther, Ewald; (Singapore,
SG) |
Correspondence
Address: |
Epping, Hermann & Fischer
Attn: Jacob Eisenberg
Ridlerstrasse 55
Munich
Bavaria
D-80339
DE
|
Family ID: |
7871319 |
Appl. No.: |
09/737656 |
Filed: |
December 18, 2000 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09737656 |
Dec 18, 2000 |
|
|
|
PCT/DE99/01655 |
Jun 7, 1999 |
|
|
|
Current U.S.
Class: |
313/504 ;
427/66 |
Current CPC
Class: |
H01L 27/3283 20130101;
H01L 51/5203 20130101 |
Class at
Publication: |
313/504 ;
427/66 |
International
Class: |
H01J 001/62 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 18, 1998 |
DE |
19827224.3 |
Claims
I claim:
1. A method of producing structured electrodes for organic
electro-luminescent displays, comprising the steps of: forming a
first layer on a substrate, said first layer having a first width
and a first solvent rate; overcoating said first layer with a
protective layer; forming a second layer on said protective layer,
said second layer having a second width and a second solvent rate;
etching said first and second layer with at least one solvent such
that said second width is greater than said first width; and
forming an electrode on said second layer.
2. The method according to claim 1, further comprising the step of:
forming at least one organic active layer on said second layer,
said active layer being formed below said electrode.
3. The method according to claim 1, wherein said first solvent rate
is higher than said second solvent rate.
4. The method according to claim 1, wherein said step of forming a
first layer further comprises the step of: forming a bottom
electrode on said substrate, said bottom electrode being formed
below said first layer.
5. The method according to claim 1, wherein the step for forming a
second layer further comprises the step of: after formation of said
second layer, cross linking said second layer.
6. The method according to claim 1, wherein the step of forming a
protective layer, further comprises the step of: cross linking a
second layer.
7. The method according to claim 1, wherein said protective layer
electrically insulates said first layer from said second layer.
8. The method according to claim 1, wherein said first layer
comprises an organic layer.
9. The method according to claim 1, wherein said second layer
comprises an organic layer.
10. The method according to claim i, wherein said first and second
layers comprise an organic layer.
11. The method according to claim 8, wherein said first layer
comprises a photoresist.
12. The method according to claim 9, wherein said second layer
comprises a photoresist.
13. The method according to claim 10, wherein said first and second
layer comprise a photoresist.
14. The method according to claim 11, wherein said photoresist is a
positive photoresist.
15. The method according to claim 12, wherein said photoresist is a
positive photoresist.
16. The method according to claim 12, wherein said photoresist is a
negative photoresist.
17. the method according to claim 13, wherein the step of forming a
first layer further comprises the step of: exposing said first
layer to radiation.
18. The method according to claim 14, wherein said photoresist
comprises one of polyglutarimid and polybenzoxazol.
19. The method according to claim 15, wherein said photoresist
comprises one of Novolak and Diaxochinon.
20. The method according to claim 16, wherein said photoresist
comprises one of Novolak, Integrater, and Photoacid.
21. The method according to claim 1, wherein said first layer
comprises a photoresist and said photoresist comprises an alkaline
developable non-photo-sensitive polyamide.
22. The method according to claim l wherein said second layer
comprises a photoresist and said photoresist comprises an alkaline
developable non-photo-sensitive polyamide.
23. The method according to claim 1, wherein both said first and
second layers comprise a photoresist and said photoresist comprises
an alkaline developable non-photo-sensitive polyamide.
24. The method according to claim 1, further comprising the steps
of: forming a second active organic layer on said substrate
adjacent to at least one of said first layers; and forming a second
top electrode on a top surface area of said second active organic
layer.
25. The method according to claim 24, wherein said top surface area
is maximized within an area having at least two borders defined by
planes tangential to said at least two of said second layers.
26. The method according to claim 24, wherein said top electrode
and second top electrode comprise a metal.
27. The method according to claim 24, wherein said top electrode
and second top electrode comprise a metal coating.
28. The method according to claim 24, wherein said top electrode
and second top electrode comprise a dielectrical layer.
29. A method of producing structured electrodes for organic
electro-luminescent displays, comprising the steps of: first
forming a bottom electrode on a semiconductor substrate; second
forming a first layer on said bottom electrode, said first layer
having a first width; third overcoating said first layer with a
protective layer; fourth forming a second layer on said protective
layer, said second layer having a second width; fifth etching said
first and second layer such that said second width is greater than
said first width; sixth forming an organic active layer on said
second layer; and seventh forming a top electrode on said second
layer.
30. The method according to claim 29, further comprising the steps
of: forming a second active organic layer on said substrate
adjacent to at least one of said first layers; and forming a second
top electrode on a top surface area of said second active organic
layer.
31. The method according to claim 30, wherein said top surface area
is maximized within an area having at least two borders defined by
planes tangential to said at least two of said second layers.
32. An optical display comprising a plurality of organic
electro-luminescent components having structured electrodes, said
components comprising: a substrate; at least one first layer formed
on said substrate, said first layer having a first width; a
protective layer overcoated on top of said first layer; a second
layer formed on said protective layer, said second layer having a
second width, said second width being greater than said first
width; an active organic layer formed on top of said second layer;
and a top electrode formed on top of said active organic layer.
33. The apparatus according to claim 32, wherein the bottom
electrode is transparent.
34. The apparatus according to claim 32, wherein said protective
layer is an electrically insulating layer.
35. The apparatus according to claim 32, the first layer has a
first solvent rate the second layer has a second solvent rate and
said first solvent rate is higher than said second solvent
rate.
36. The apparatus according to claim 32, wherein the second layer
is cross linked.
37. The apparatus according to claim 32, wherein said first layer
comprises an organic layer.
38. The apparatus according to claim 32, wherein said second layer
comprises an organic layer.
39. The apparatus according to claim 32, wherein said first and
second layers comprise an organic layer.
40. The apparatus according to claim 37, wherein said first layer
comprises a photoresist.
41. The apparatus according to claim 38, wherein said second layer
comprises a photoresist.
42. The apparatus according to claim 39, wherein said first and
second layer comprise a photoresist.
43. The apparatus according to claim 37, wherein said photoresist
is a positive photoresist.
44. The apparatus according to claim 38, wherein said photoresist
is a positive photoresist.
45. The apparatus according to claim 38, wherein said photoresist
is a negative photoresist.
46. The apparatus according to claim 31, wherein said photoresist
comprises one of polyglutarimid and polybenzoxazol.
47. The apparatus according to claim 38, wherein said photoresist
comprises one of Novolak and Diaxochinon.
48. The apparatus according to claim 38, wherein said photoresist
comprises one of Novolak, Integrater, and Photoacid.
49. The apparatus according to claim 29, further comprising; a
second active organic layer on said substrate adjacent to at least
one of said first layers; and a second top electrode on a top
surface area of said second active organic layer.
50. The method according to claim 49, wherein said top surface area
is maximized within an area having at least two borders defined by
planes tangential to said at least two of said second layers.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of copending
international application PCT/DE99/01655, filed Jun. 7, 1999, which
designated the United States.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for producing
structured electrodes and especially organic electro-luminescent
components with structured electrodes. The components are used in
displays and the like and further comprise structured metal
electrodes, The electrode is supported by multiple layers of
varying widths and heights such that in combination with other
supports, active organic layers may be tightly packed into a
display area. A possible arrangement includes the active layers
layered below a top electrode.
[0004] 2. Description of Related Art
[0005] Thin layers, in particular those with a thickness of 1 nm to
10 .mu.m, find diverse technological applications in for example:
semiconductor production; and microelectronic, sensory and display
technologies. Production of the organic electro-luminescent
components almost always includes the structuring of necessary
layers; whereas the necessary structure sizes go from the
sub-.mu.-area to the entire substrate area. In addition, the
required component form varieties are practically unlimited.
[0006] In general, there are many available lithographic processes
available for structuring electrodes. That which most all the
processes have in common, is that the layers to be structured come
into contact with more or less caustic chemicals, including
photoresists, solvents, developing fluids, and corrosive gases.
Such contact leads, during some applications, to corrosion or at
least damage of the layers to be structured. This is often the case
for organic light emitting diodes.
[0007] Organic Light Emitting Diodes (OLEDs), i.e.
electro-luminescent diodes, are predominately used in displays.
Examples of such applications are set out in U.S. Pat. Nos.
4,356,429 and 5,247,190. An example method of producing electrodes
in general is set out in German patent registration reference 197
45 610.3. The structure and production of OLED displays typically
occurs as follows.
[0008] A substrate, for example glass, is coated entirely with a
transparent electrode--bottom electrode, anode. The bottom
electrode comprises for example indium-tin-oxide (ITO). To produce
pixel-matrix-displays, the transparent bottom electrode as well as
later formed top electrode (cathode), must be structured.
Accordingly, both electrodes are usually structured in the form of
parallel strip conductors. The strip conductors of the bottom and
top electrodes tend to run vertically with respect to each other,
The structuring of the bottom electrode occurs via a
photolithographic process which includes wet chemical etching
methods, the details of which are known to one skilled in the art.
The etched final structure, which is obtainable with this method,
is essentially limited by the photolithographic steps and the
consistency of the bottom electrode. According to the current state
of the art, pixel sizes as well as non-emitting spaces between the
pixels can be realized to a size of few micrometers. The lengths of
the strip shaped strip conductors of the bottom electrode can be up
to many centimeters. According to current lithographic masking,
emitting areas up to several square centimeters can also be
produced. The sequence of each emitting area can be regular
(pixel-matrix-display) or variable (symbol presentations).
[0009] One or more organic layers are applied on a substrate, the
substrate including the structured transparent bottom electrode.
These organic layers may comprise polymers, oligomers, and low
molecular combinations or mixtures thereof. To apply polymers, for
example polyanilin, poly (p-phylenvinylen) and poly
(2-methoxy-5-(2'ethyl) hexyloxy-p-phenylenvinylen), generally
liquid phase processes are used (application of a solution by spin
coating or blading); while for low molecular and oligomer
combinations a gas phase deposition is preferred (Evaporation or
Physical Vapor Deposition, PVD). Examples of preferred low
molecular layers include the following combinations transported by
positive charge carriers:
N,N'-to-(3-methylphenyl)-N,N'-to'(phenyl)benzid- in (m-TPD),
4,4',4"-Tris-(N-3-methylphenyl-N-phenylamino)-triphenylamin
(m-MTDATA) and 4,4',4"-Tris-(carbazol-9-yl)-triphenylamin (TCTA).
Hydroxychinoline-aluminium-III-salt (Alq) is used, for example as
an emitter, which can be remunerated with suitable chromophores
(Chincridon-derivates, aromatic hydrocarbons, etc.). If necessary,
exemplary existing additional layers which influence the
electro-optical characteristics as well as the long-term
characteristics may be copper-phthalocyanine. The entire thickness
of the layer sequence can be between 10 nm and 10 .mu.m, typically
lying in the range of 50 to 200 nm.
[0010] The top electrode usually comprises a metal which is
generally applied by gas phase deposition (thermic deposition,
sputtering or cathode rays deposition). Preferred compositions are
base and therefore reactive metals, especially to water and oxygen,
and include lithium, magnesium, aluminum and calcium as well as
alloys of these metals. For the production of a pixel-matrix-order
structure having metal electrodes, the structure is obtained
generally by the metal being applied through a mask opening.
[0011] A produced OLED-display, according to this method, may
additional contain electro-optical features such as: UV-filters,
polarization filters, anti-reflex-coatings, and (micro-cavities)
known installations such as color conversion and color correctional
filters. In addition, a hermetically sealed packaging may be
provided by which the organic electro-luminescent displays are
protected from external environmental influences such as humidity
and mechanical strains. In addition, thin film transistors for
individual picture elements (pixel) can be present.
[0012] For high resolution displays for which the presentation of
large informational content is possible, a fine structuring of the
metal electrodes in the form of strip conductors is necessary, i.e.
the width of the strip conductors as well as the spacing
therebetween must be structured in keeping with narrow tolerances
in the microns. Herein, the width of a strip conductor can lie
between 10 .mu.m and several hundred micrometers, preferably
between 100 and 300 .mu.m. To reach a high filling factor (share of
the active light emitting area versus the entire display area) it
is additionally necessary that the spaces between the metallic
strip conductors as well as the spaces between the strip conductors
of the transparent bottom electrode are only a few micrometers.
Established structuring techniques can not be used here because the
existing active organic layers, i.e. the electro-luminescent
materials, are not resistant to the necessary chemicals for such
fine structuring.
[0013] By so called shadow masking, i.e. thin metals or segments
with correspondingly formed openings for a desired structure, only
layers can be structured and produced according to CVD or PVD
(chemical vapor deposition, physical vapor deposition) methods.
Furthermore, the obtainable dissolution produces (based on the
finite distance between masking and substrate) relatively inferior
results and large areas (as a result of a bending of the shadow
masking) which cannot be realized in view of production
engineering.
[0014] A lift off method for the production of structured
metallizations by use of two separate photoresist layers is known
from German reference DE-A44 01 590. Relatively thick metal
structures on semiconductor components can be produced by this
method.
[0015] Furthermore European reference EP-A-0 732 868 shows a method
for the production of an organic electro-luminescent display
device. For this, on a multiple number of first display electrodes,
electrically insulated overhanging structures are produced, which
are built up from a first layer, for example of polyamide, and a
second layer of for example SiO.sub.2. Afterwards, organic
functional layers for different color components or also an only
color component are applied in the areas between the electrically
insulated structures by use of (shadows) masks, and following this
the material for the second display electrode is precipitated on
the organic functional layers and the electrically insulated
structures.
BRIEF SUMMARY OF THE INVENTION
[0016] It is an object of the invention to provide a generally
applicable structuring technique for electrodes, i.e. a technique
which is subject, as little as possible, to limitations regarding
geometry (structure size, forms, areas) and production (CVD and PVD
methods, solvent processes). In particular, the instant method
allows for suitable mass production of structured electrodes in
organic electro-luminescent components, and in particular of fine
structured metallic top electrodes for highly dissolvent displays
wherein the electrodes to be structured are not damaged by
chemicals.
[0017] With the foregoing and other objects in view, there is
provided in accordance with the invention a method of producing
structured electrodes for organic electro-luminescent displays,
comprising the steps of: forming a first layer on a substrate, said
first layer having a first width and a first solvent rate; forming
a protective layer over said first layer; forming a second layer on
said protective layer, said second layer having a second width and
a second solvent rate; etching said first and second layer with at
least one solvent such that said second width is greater than said
first width; and forming an electrode on said second layer.
[0018] The present invention may further comprises a method of
producing structured electrodes for organic electro-luminescent
displays, comprising the steps of: first forming a bottom electrode
on a semiconductor substrate, second forming a first layer on said
bottom electrode, said first layer having a first width and a first
solvent rate; third forming an electrically insulating protective
layer over said first layer; fourth forming a second layer on said
protective layer, said second layer having a second width and a
second solvent rate; fifth etching said first and second layer with
at least one solvent such that said second width is greater than
said first width; sixth forming an organic active layer on said
second layer; and seventh forming a top electrode on said second
layer. And in addition, the method may be applied where only one
solvent is used and said first and second layers are reactive to
said one solvent.
[0019] By this invention, a new method for a maskless production of
structured electrodes, especially for organic electro-luminescent
components, is realized. This method especially enables the
production of structured metal electrodes, particularly for
organic-electro-luminescent displays. By this method, structures
can be produced which are suitable for wide area displays and in
addition the possibility of the structuring of metal electrodes on
electro-luminescent polymers. The instant method is also especially
suitable for lithographic applications.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0020] The FIGURE depicts a schematic cross section of an example
embodiment of an organic light emitting diode produced in
accordance with the instant method.
DETAILED DESCRIPTION OF THE INVENTION
[0021] As depicted, the diode comprises a substrate 1, with a
structured bottom electrode 2 layered thereon. Electrode 2 may be
transparent. The electrode 2 may further comprise a non-planar
geometry of glass, metal, silicon or polymer (in the form of a
foil). Electrode 2 may further comprise an ITO electrode
(ITO=Indium Tin Oxide). Atop the electrode 2, a first layer 3 is
formed, the details of which are set out below. A protective layer
is formed on layer 3 (not shown). The layer may be electrically
insulating and comprise any properties known to one skilled in the
art to accomplish the same. Likewise, the layer may prevent
intermixing, as discussed below, and further comprise any suitable
materials for the same. Atop the protective layer, a second layer 4
is formed. Thereon, an active organic layer 5 is formed and still
further a top electrode 6. The top electrode may be a metal. As set
out in more detail below, the first and second layers are formed
such that the second layer overhangs the first layer. In the spaces
between the above-described structure, a second active organic
layer 5 and top electrode 6 may be formed--second formation, The
first and second active organic layers and top electrodes may be
identical, different and/or related in composition and function.
The height and width of the second formation is engineered so as to
maximize exposure of the active organic layer, in the top
direction, from between adjacent structured electrode formations or
along side at least one electrode formation.
[0022] By way of more detail, according to the instant method, two
layers are preferably applied on a bottom electrode, itself
positioned on a substrate. On a second of the two layers, (after
structuring, structure transmission and integration) at least one
active organic layer is applied. Then on the active organic
functional layer a top electrode is deposited.
[0023] The top electrode, which preferably includes few escaping
electrons, functions as an electron-receiving electrode, and
comprises a metal or a metallic coating. In addition, this
electrode may also include a layered arrangement, wherein on a thin
dielectrical layer (<5 nm), which for example comprises
lithiumfluoride or aluminiumoxide, a metal or ITO layer as a
(transparent) electrode.
[0024] According to the present inventive method, it is essential
that the first lower electrode, which can be a structured or
applied layer, is not damaged by applying the second upper layer
and as such between both layers a defined boundary is maintained.
The first and/or second layer preferably comprises an organic film
developing material, such as a photoresist.
[0025] Photoresists are radiation sensitive film developing
materials whose solubility changes with exposure to radiation.
Herein, it is distinguished between use of positive and negative
photoresists. When the upper and lower layers comprise a
photoresist and each are sensitive to approximately the same
radiation wavelength, the lower photoresist may not be a negative
photoresist.
[0026] According to a preferred embodiment of the present
invention, wherein an essential characteristic of the embodiment
includes a photolithographic process, at least two layers are
selectively applied on a transparent bottom electrode, wherein the
first layer comprises a resist or photoresist and the second layer
comprises a positive or negative photoresist layer, and in the case
where the first layer comprises a photoresist layer, the first
layer with be exposed to radiation prior to the application of the
second layer. The layers are then structured in such a way that the
active organic layers and top electrodes may be respectively
applied and/or deposited on the second layer. The layers are
structured in a vertical direction with respect to the length of
the bottom electrode. The application of the active organic layers
on the second layer can generally occur by thermic deposition
processes as well as by solvent applications, such as spinning or
blading following drying.
[0027] At the photolithographic method step, the first of the two
layers must be overcoatable or overcoated with a protective layer.
This means, that both layers can be applied on top of each other
without a so called intermixing, i.e. applied coatings dissolvable
in different solvents, such that the (photo)resist of the first
layer is not affected by the solvent for the photoresist of the
second layer. Accordingly, the applied first layer is preserved
during application of the second layer. Likewise, between the two
layers a defined boundary is effected.
[0028] For the photolithographic method step it is additionally
recommended, that the first layer has a higher developing rate than
the second layer. As such, after the exposure, by the necessary
structuring treatment of the photoresist layers, the first layer
dissolves faster with a developing solvent than the second layer.
It is of advantage here, if both layers can be treated i.e.
developed, with the same developer, preferably a watery-alkaline
developer.
[0029] In general, for the lower layer, electrical insulating
organic and inorganic materials are used. Suitable inorganic
materials include: silicondioxide; siliconnitrite; and
aluminiumoxide. But the lower layer may for example also comprise
an alkaline developing non-photo sensitive polyamide. It is
advantageous if the lower layer is photosensitive and preferably
comprises a positive photoresist on the basis of polyglutarimide or
polybenzoxazol.
[0030] The upper layer is preferably also a photoresist. This layer
comprises a positive photoresist (Positivresist) of a
Novolak/Diazochinon-basis or a negative photoresist (Negativresist)
on the basis of Novolak/Integrater/photo acid. For the
positiveresist polymethylmethacrylate (PMM) may be used, and as
negativeresist an integratable polysilpheylensiloxanes may be
used.
[0031] However, it is also possible to indirectly structure the
upper layer. An amorphous carbon (a-C) or amorphous hydrogen carbon
(a-C:H) serves, for example, as a coating material. Such layers are
structured in an oxygen plasma, whereas a corrosive masking is used
in the form of a silicon photoresist layer, particularly a
so-called CARL-resist (CARL=Chemical Amplification of Resist Line)
or a TSI system (TSI=Top Surface Imaging).
[0032] Following the above described method, a structure as shown
in the figure is created, wherein the second layer shows a larger
structure width than the first layer (overhanging structure). The
second layer, which consists preferably of a film developing
organic material, is cross-linked, whereby the mechanical stability
and the thermic resistance is elevated. The overhanging structure
will not be impaired by the cross-linking.
[0033] Based on the cross-linking, the overhanging of the second
layer will be stabilized, so that larger areas, especially long
borders, can be realized and the layer production can take place by
solvent processes. The stable overhanging then produces the
structure of the following applied layers because at the border of
the overhanging by, CVD- or PVD as well as from liquid phase
processes, applied layers are cut off and therefore separated in to
different zones, i.e. structured. In particular, these are active
organic layers, i.e. electro-luminescent layers, and
electrodes.
[0034] As discussed above, the upper layer shows a wider
structuring width after the structuring than the lower layer. The
difference in the structuring width (overhanging) is preferably
between 1 and 10 .mu.m. Preferably, the thickness of the lower
layer is 0.1 to 30 .mu.m and in particular 0.5 to 10 .mu.m, and the
thickness of the upper layer 0.1 to 30 .mu.m and in particular 0.5
to 5 m.
[0035] The following are two examples of implementing the
above-described method.
EXAMPLE 1
Production of an OLED Display
[0036] The production of a display proceeds according to the
following method steps:
[0037] 1. An entire area of a glass sheet is coated with
indium-tin-oxide (ITO) and then structured according to a
photolithographic method followed by wet chemical etching, in such
a way that parallel conductor strips with a width of approximately
200 .mu.m and a space of approximately 50 .mu.m are formed. The
photoresist used during structuring is then completely removed. The
conductor strips are each approx. 2-cm long and include at their
outer ends additions for external contacting if applicable,
[0038] 2. The glass sheet will be heated approximately 1 hour at a
temperature of 250.degree. C., then a commercial photoresist on the
basis of polyglutarimide will be spun on (application for a
duration of 10 seconds at 700 rotations/minute, then spun off for
30 seconds at 3000 rotations/minute). The received layer will be
dried for 15 minutes at 150.degree. C. and then 30 minutes at
250.degree. C. in a circulating air oven. A streaming exposure at a
wavelength of 248 nm (polychromatic) with a dose of 100 mJ/cm.sup.2
is created afterwards. Then a commercial photoresist on the basis
of Novolak/Diazochinone (10:1 thinned with
(1-mehtoxy-2-propyl)acetate) will be spun on at 2000
rotations/minute for 20 seconds. Both layers will be dried 60
seconds at 100.degree. C., and afterwards with a radiation dose of
62 mJ/cm.sup.2 at a wavelength of 365 nm (polychromatic) via
lithographic masking. Then with a commercial developer which
contains tetramethylammoniumhydroxyde, the structure is developed
for 20 seconds. Afterwards the glass sheet will be put into a
100.degree. C. preheated air circulating oven and annealed for 45
minutes at 230.degree. C.; thereby cross-linking the upper
photoresist. Then the described developer develops twice more for
70 seconds; thereby an overhanging of the upper layer of
approximately 5 .mu.m is created. The layer thickness of the lower
layer is approximately 2.6 .mu.m; both layers together are approx.
4.3 .mu.m thick. Afterwards, resist remnants will be removed for 90
seconds from the ITO surface by oxygen plasma (RF capacity: 70 W,
gas flux: 30 sccm),
[0039] 3. At a pressure of 10.sup.-5 mbar, a layer of
N,N'-(3methylpheyle)-N,N'-(phenyl)-benzidin (m-TPD) will be applied
by conventional vapor deposition (layer thickness: 135 nm,
deposition rate: 0.2 nm/s).
[0040] 4. Without the use of a mask, a 100 nm thick layer of
magnesium will be applied on the active surface of the display by
thermic deposition (deposition rate: 1 nm/s, pressure:10.sup.-5
mbar), Interrupting the vacuum, a 100 nm thick layer of silver nm
will be applied, also by vapor deposition, on the active display
area (deposition rate: 1 nm/s, pressure: 10.sup.-5 mbar). The
resulting display flashes are clearly visibly in the day light and
the emission color is greenish-yellow.
EXAMPLE 2
Production of an OLED Display
[0041] A 1% solvent of an electro-luminescent polymer on the basis
of fluorines in Xylole is spun on (4000 rotations/min, 30 s) a
glass sheet with a produced layer build up corresponding to example
1. Afterwards, it is dried for 60 seconds at 85.degree. C. Without
the use of masking, a 100 nm thick layer of calcium will be applied
on the active area of the display by vapor deposition (deposition
rate: 1 nm/s, pressure: 10.sup.-5 mbar). Without interrupting the
vacuum, a 100 nm thick layer of silver will also be applied on the
active display area by vapor deposition (deposition rate; 1 nm/s,
pressure: 10.sup.-5 mbar).
[0042] The display flashes are clearly visibly in the day light and
the emission color is greenish-yellow. The invention being thus
described, it will be obvious that the same may be varied in many
ways. Such variations are not to be regarded as a departure from
the spirit and scope of the invention, and all such modifications
would be obvious to one skilled in the art intended to be included
within the scope of the following claims,
* * * * *