(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2002/0158835 A1
`Kobayashi et al.
`(43) Pub. Date:
`Oct. 31, 2002
`
`US 2002O158835A1
`
`(54) DISPLAY DEVICE AND METHOD OF
`MANUFACTURING THE SAME
`(76) Inventors: Michiya Kobayashi, Fukaya-shi (JP);
`Kazushige Yamamoto, Yokohama-shi
`(JP)
`Correspondence Address:
`Pillsbury Winthrop LLP
`1600 Tysons Boulevard
`McLean, VA 22102 (US)
`(21) Appl. No.:
`10/125,612
`(22) Filed:
`Apr. 19, 2002
`(30)
`Foreign Application Priority Data
`
`Apr. 20, 2001 (JP)...................................... 2001-122485
`Apr. 20, 2001 (JP)...................................... 2001-122884
`
`Publication Classification
`
`(51) Int. Cl. ................................................... G09G 3/36
`(52) U.S. Cl. .............................................................. 345/100
`
`(57)
`
`ABSTRACT
`
`An active matrix type planar display device includes display
`elements arranged in a matrix and auxiliary wiring elements.
`The display element has an optical active layer between a
`first electrode formed on a Substrate and a Second electrode.
`The auxiliary wiring element is formed in the same layer or
`on the same Surface as the first electrode, electrically insu
`lated from the first electrode, and electrically connected to
`the Second electrode.
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`

`Patent Application Publication
`
`Oct. 31, 2002 Sheet 1 of 7
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`US 2002/0158835 A1
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`Patent Application Publication
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`Oct. 31, 2002. Sheet 2 of 7
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`US 2002/0158835 A1
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`Patent Application Publication Oct. 31, 2002 Sheet 3 of 7
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`US 2002/0158835 A1
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`Patent Application Publication Oct. 31, 2002. Sheet 4 of 7
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`US 2002/0158835 A1
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`Patent Application Publication Oct. 31, 2002 Sheet 5 of 7
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`US 2002/0158835 A1
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`III"
`FIG. 6A (iii.
`
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`Patent Application Publication Oct. 31, 2002 Sheet 6 of 7
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`US 2002/0158835A1
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`Patent Application Publication Oct. 31, 2002 Sheet 7 of 7
`
`US 2002/0158835 A1
`
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`

`US 2002/0158835 A1
`
`Oct. 31, 2002
`
`DISPLAY DEVICE AND METHOD OF
`MANUFACTURING THE SAME
`
`BACKGROUND OF THE INVENTION
`0001. The present invention relates to a planar display
`device Such as an organic electroluminescence (EL) display
`device, and a method of manufacturing the same. In par
`ticular, this invention relates to an active matrix type planar
`display device and a method of manufacturing the same.
`0002 There has been an increasing demand for planar
`display devices, represented by liquid crystal displayS,
`which are thinner, lighter and less in power consumption
`than CRT display devices. In particular, active matrix type
`planar display devices, wherein each display element is
`provided with a Switching device, have been applied to
`various displays of mobile information apparatuses, etc. The
`active matrix planar display device has a high display
`quality, with no croSStalk between adjacent display ele
`mentS.
`0003 Recently, organic electroluminescence (EL) dis
`play devices have been widely developed as Self-lumines
`cence type displays, which realize higher response Speeds
`and wider angles of View field. The organic EL display
`device comprises an organic EL panel and an external drive
`circuit for driving the organic EL panel. The organic EL
`panel comprises a display region in which display elements
`are arranged in a matrix on a Support Substrate of glass, etc.,
`and a drive circuit region for driving the display elements by
`signals from the external drive circuit. Each display element
`comprises a first electrode, a Second electrode disposed to
`oppose the first electrode, and an organic light-emission
`layer disposed between the first and Second electrodes.
`0004.
`In the organic EL display device, EL light is let out
`by a back-face luminescence method in which light is
`emitted via the Support Substrate, or a top-face luminescence
`method in which light is emitted from the Side opposing the
`Support Substrate. In the active matrix type organic EL
`display device adopting the back-face luminescence method,
`circuits of thin film transistors (TFTS), which block trans
`mission of EL light, are disposed under the organic light
`emission layer. It is thus difficult to obtain a sufficient
`opening ratio, posing a problem of how the efficiency in use
`of light is to be enhanced. On the other hand, the organic EL
`display device adopting the top-face luminescence method
`has Such a structure that the opening ratio can be determined
`regardless of the circuits disposed on the Support Substrate
`Side. Thus, highly efficient use of light is achieved.
`0005. In the planar display device, it is imperative that the
`light-emission-side electrode disposed on the Side of light
`emission be formed of a light-transmissive conductive film.
`In the case of the active matrix display device using the
`top-face luminescence method, it is necessary that a com
`mon electrode disposed on the light emission side be formed
`of a light-transmissive conductive film. It is generally
`known, however, that a transparent conductive material with
`light transmissivity has a higher resistivity than ordinary
`metal materials by two or three orders.
`0006 The use of transparent conductive material may
`lead to non-uniformity in electrode Voltage in the Screen
`plane of the light-emission-side electrode, degrading the
`display quality. This problem becomes more conspicuous as
`
`the Screen size increases. Incidentally, another problem may
`arise that the Screen Size needs to be limited.
`0007 AS has been stated above, in the prior art, it is
`difficult to use the active matrix display device using the
`top-face luminescence method.
`
`BRIEF SUMMARY OF THE INVENTION
`0008. The present invention has been made in consider
`ation of the above problems, and an object of the invention
`is to provide a display device capable of Suppressing display
`non-uniformity in a display Screen and enhancing the dis
`play quality, and a method of manufacturing the Same.
`0009. Another object of the invention is to provide a
`display device capable of increasing the degree of freedom
`in determining the Screen size.
`0010 Still another object of the invention is to provide an
`active matrix display device using a top-face luminescence
`method, and a method of manufacturing the Same.
`0011 Still another object of the invention is to provide a
`method of manufacturing a display device without a
`decrease in productivity.
`0012. According to a first aspect of the invention, there is
`provided a display device comprising a plurality of Scan
`Signal lines arranged on a Substrate, a plurality of Video
`Signal lines arranged Substantially perpendicular to the Scan
`Signal lines, Switching elements disposed near interSections
`between the Scan signal lines and the Video Signal lines, and
`display elements each having an optical active layer formed
`in an insular shape between a first electrode connected to the
`Switching element and a Second electrode disposed to
`oppose the first electrode, the display elements being
`arranged in a matrix,
`0013 wherein the display device further comprises
`an auxiliary wiring element formed in the same layer
`or on the same Surface as the first electrode, electri
`cally insulated from the first electrode, and electri
`cally connected to the Second electrode.
`0014. According to a second aspect of the invention,
`there is provided a method of manufacturing a display
`device wherein display elements, each having an optical
`active layer between a first electrode formed on a Substrate
`and a Second electrode disposed to oppose the first electrode,
`are arranged in a matrix, the method comprising the Steps of:
`0015 forming the first electrode and an auxiliary
`wiring element of a conductive material in one Step;
`0016 forming an insulating film having a region
`that exposes the first electrode and the auxiliary
`wiring element;
`0017 forming the optical active layer in the region
`of the insulating film, which exposes the first elec
`trode; and
`0018 disposing a light-transmissive conductive film
`over Substantially an entire Surface of the Substrate to
`form the Second electrode that is opposed to the first
`electrode via the optical active layer and electrically
`connected to the auxiliary wiring element.
`0019. According to a third aspect of the invention, there
`is provided a display device comprising a plurality of Scan
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`US 2002/0158835 A1
`
`Oct. 31, 2002
`
`Signal lines arranged on a Substrate, a plurality of Video
`Signal lines arranged Substantially perpendicular to the Scan
`Signal lines, Switching elements disposed near interSections
`between the Scan signal lines and the Video Signal lines, and
`display elements each having an optical active layer formed
`in an insular shape between a first electrode connected to the
`Switching element and a Second electrode disposed to
`oppose the first electrode, the display elements being
`arranged in a matrix,
`0020 wherein the first electrode is formed indepen
`dently for each of the display elements, and the
`Second electrode is formed commonly for the display
`elements, and
`0021 auxiliary wiring elements that are electrically
`insulated from the first electrode and electrically
`connected to the Second electrode are arranged more
`densely in a central area than in a peripheral area
`within a Surface of the Substrate.
`0022. According to a fourth aspect of the invention, there
`is provided a method of manufacturing a display device
`wherein display elements, each having an optical active
`layer between an anode formed on a Substrate and a cathode
`disposed to oppose the anode, are arranged in a matrix, the
`method comprising the Steps of
`0023 forming the anode of a conductive material in
`an insular shape;
`0024 forming an auxiliary wiring element of a
`conductive material;
`0025 forming the optical active layer on the anode;
`and
`0026 disposing a light-transmissive conductive film
`over Substantially an entire Surface of the Substrate to
`form the cathode that is opposed to the anode Via the
`optical active layer and electrically connected to the
`auxiliary wiring element.
`Additional objects and advantages of the invention
`0.027
`will be set forth in the description which follows, and in part
`will be obvious from the description, or may be learned by
`practice of the invention. The objects and advantages of the
`invention may be realized and obtained by means of the
`instrumentalities and combinations particularly pointed out
`hereinafter.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWING
`0028. The accompanying drawings, which are incorpo
`rated in and constitute a part of the Specification, illustrate
`presently preferred embodiments of the invention, and
`together with the general description given above and the
`detailed description of the preferred embodiments given
`below, Serve to explain the principles of the invention.
`0029 FIG. 1 is a plan view schematically showing the
`Structure of an organic EL display device according to an
`embodiment of the present invention;
`0030 FIG. 2 is a partial plan view schematically show
`ing the Structure of a display region of the organic EL
`display device shown in FIG. 1;
`
`FIG. 3 is a partial cross-sectional view, taken along
`0031
`line A-Ain FIG.2, Schematically showing an example of the
`Structure of the display region of the organic EL display
`device;
`0032 FIG. 4 is a table showing resistivities of metal
`materials and transparent conductive materials,
`0033 FIGS. 5A to 5F are plan views showing examples
`of arrangement of auxiliary wiring and Second electrode
`power Supply lines according to the embodiment of the
`invention;
`0034 FIGS. 6A to 6C are plan views showing examples
`of arrangement of a first electrode and auxiliary wiring
`according to the embodiment of the invention;
`0035 FIG. 7 is a partial cross-sectional view, taken along
`line A-A in FIG. 2, Schematically showing another example
`of the Structure of the display region of the organic EL
`display device;
`0036 FIG. 8 is a partial plan view schematically show
`ing an example of arrangement of auxiliary wiring in the
`display region of the organic EL display device shown in
`FIG. 7;
`0037 FIG. 9 is a graph showing a measurement result of
`a panel-face luminance of the organic EL display device, as
`measured along line B-B in FIG. 5A; and
`0038 FIG. 10 is a graph showing a measurement result
`of a panel-face luminance of an organic EL display device,
`which is not provided with auxiliary wiring.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`0039. An active matrix type planar display device accord
`ing to an embodiment of the present invention will now be
`described in detail with reference to the accompanying
`drawings. In this embodiment, a Self-luminescence type
`display device, more Specifically, an organic EL display
`device, is described as the active matrix type planar display
`device.
`0040 FIG. 1 is a plan view schematically showing the
`Structure of an organic EL display device according to an
`embodiment of the present invention. FIG. 2 is a partial plan
`View Schematically showing the Structure of a display region
`of the organic EL display device shown in FIG. 1. FIG. 3
`is a croSS-Sectional view taken along line A-A in FIG. 2.
`0041 AS is shown in FIGS. 1-3, an active matrix type
`organic EL display device 1 comprises an organic EL panel
`2 and an external drive circuit 3 for driving the organic EL
`panel 2. The organic EL panel 2 comprises three kinds of
`display elements P, which respectively emit red, green and
`blue light. The organic EL panel 2 includes a display region
`10 where the display elements P are arranged in a matrix.
`0042 Specifically, in this embodiment, the display region
`10 has a size of 10.4 (10.4 inches in diagonal dimension). In
`the display region 10, video signal lines 109 and scan signal
`lines 107 are arranged in a matrix on an insulative Support
`Substrate 101 of glass, etc. A Scan signal line drive circuit
`Ydr for Supplying drive pulses to the scan signal lines 107
`and a video Signal line drive circuit Xdr for Supplying drive
`Signals to the Video signal lines 109 are disposed at periph
`eral areas of the display region 10.
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`Oct. 31, 2002
`
`0043. In the display region 10, the organic EL panel 2
`includes an n-type TFT functioning as a Switching element
`SW1, a capacitor 110 for holding a video signal voltage, a
`p-type TFT functioning as a driving control element SW2,
`and an organic EL display element P. The Switching element
`SW1 is formed near each of intersections between the video
`signal lines 109 and scan signal lines 107. The driving
`control element SW2 is connected in series to the organic EL
`display element P. The Video signal Voltage holding capaci
`tor 110 is connected in series to the Switching element SW1
`and in parallel to the driving control element SW2.
`0044) The organic EL display element P comprises a first
`electrode 117 formed of a light-reflecting conductive film,
`which is connected to the driving control element SW2; an
`organic light-emission layer 121 functioning as a light active
`layer, which is disposed on the first electrode 117; and a
`Second electrode 122 disposed to be opposed to the first
`electrode 117 via the organic light-emission layer 121. The
`organic light-emission layer 121 may comprise three Stacked
`layers, i.e. a hole carrying layer and electron carrying layer,
`which are common for all the colors, and a light-emission
`layer formed for each of the different colors. Alternatively,
`the organic light-emission layer 121 may be formed of two
`or one function-integrated layer. The organic light-emission
`layer 121 is formed on that part of the first electrode 117,
`which is exposed to an opening portion 120b of a partition
`wall 120 that separates each display element P and is formed
`of a black resist material with a thickness of 3 lim.
`004.5 The organic EL display device adopts the top-face
`luminescence method in which the display Surface is pro
`vided on the Second electrode (light-emission-side elec
`trode) 122 side. The second electrode 122 of display element
`P is formed of a light-transmissive conductive film. The
`light-transmissive conductive film is made, for example, by
`using a transparent conductive material with high transpar
`ency, or by thinning a low-transparency material to increase
`its transparency. In this embodiment, a barium (Ba) layer is
`thinned to, e.g. 10 nm, So as to have transparency. The
`barium layer is formed as the transparent conductive film
`commonly for all display elements. The sheet resistance of
`this transparent conductive film was about 10 S2/
`0046) The organic EL display device of this embodiment
`includes auxiliary wiring elements 118 electrically con
`nected to the light-transmissive Second electrode 122. Spe
`cifically, as shown in FIG. 3, the auxiliary wiring element
`118 and the first electrode 117 are formed in the same layer
`or on the same Surface, and the auxiliary wiring element 118
`is electrically insulated from the first electrode 117 by the
`partition wall 120. The auxiliary wiring element 118 is
`electrically connected to the Second electrode 122 via a
`contact portion 120a that is provided in the partition wall
`120 so as to expose the auxiliary wiring element 118. The
`auxiliary wiring elements 118 are formed in a lattice shape
`so as to surround the first electrode 117 of each display
`element P. The auxiliary wiring elements 118 are intercon
`nected over the entire display region 10.
`0047 The organic EL display device has the auxiliary
`wiring elements 118, which are electrically connected to the
`second electrode 122 and uniformly provided over the entire
`display region 10. Thus, a potential variance can be Sup
`pressed within the Screen Surface of the light-emission side
`electrode, i.e. the Second electrode 122.
`
`0048. It is desirable that the auxiliary wiring element 118
`be formed of an electrically conductive material having a
`Sufficiently low resistivity, compared to the conductive
`material of the second electrode 122. More specifically, the
`auxiliary wiring element 118 should preferably be formed of
`a conductive material having a resistivity of 11x10 G2cm.
`By forming the auxiliary wiring element 118 of the low
`resistance conductive material, the potential variance within
`the Screen Surface of the light-emission-side electrode can
`further be reduced.
`0049 FIG. 4 shows the electrical resistivity (us2cm) of
`typical metal materials chosen for the auxiliary wiring
`element 118 and the electrical resistivity (uS2cm) of trans
`parent conductive materials. It is preferable, in particular,
`that the auxiliary wiring element 118 be formed of a con
`ductive material with a resistivity of 1x10 G2cm to 6x10
`G2cm. For example, the auxiliary wiring element 118 is
`formed of the following metals or alloys: silver (resistivity:
`1.6 uS2cm), copper (1.7 u2cm), Silver-palladium-copper
`alloy (2.2 uS2cm), gold (2.4 uS2cm), aluminum (3.0 uS2cm),
`aluminum-neodymium alloy (4.7 u2cm), titanium (5.0
`AuS2cm), molybdenum (5.6 uS2cm), and tungsten (5.6 uS2cm).
`Alternatively, a composite material of these may be used.
`0050. In this embodiment, the auxiliary wiring element
`118 is formed of the same material as the first electrode 117.
`For example, it is formed of three Stacked layers of alumi
`num (Al), molybdenum (Mo) and indium-tin-oxide (ITO).
`This stacked body is formed to have a resistivity of 4x10
`tuS2cm and a sheet resistance of 10' uS2/D. The Mo is
`provided to prevent corrosion of ITO and Al due to their
`direct contact. The Mo may be replaced with other metals
`having the same function, Such as titanium (Tl) and tungsten
`(W).
`0051 AS has been described above, the first electrode 117
`functions as the anode of the organic EL display element,
`and the second electrode 122 as the cathode thereof. It is
`desirable to use optimal materials depending on the polarity
`of the electrode. When the auxiliary wiring element 118 and
`the first electrode 117 are formed by the same process, it is
`imperative to choose the conductive material that has a low
`resistance and functions with good performance as the
`electrode.
`0.052 FIGS. 5A to 5F show examples of arrangement of
`auxiliary wiring element 118 and Second electrode power
`supply lines, and FIGS. 6A to 6C are enlarged views of
`display regions in FIGS. 5A to 5C.
`0053. In the above-described embodiment, as shown in
`FIGS. 5A and 6A, auxiliary wiring elements 118 surround
`the first electrode 117 of each display element P and are
`interconnected and uniformly patterned on the display
`region. Alternatively, the auxiliary wiring elements 118 may
`be formed with various patterns. It should suffice if the
`auxiliary wiring elements 118 are electrically isolated from
`the first electrodes 117 and electrically connected to the
`Second electrode 122.
`0054 For example, the auxiliary wiring elements 118
`may be arranged with varying density within the panel
`surface. As is shown in FIGS. 5B and 6B, the auxiliary
`wiring elements 118 may be formed within second electrode
`power Supply lines 119 arranged in a rectangular shape to
`Surround the display region Such that the density of arrange
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`US 2002/0158835 A1
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`Oct. 31, 2002
`
`ment is high at a central area far from the Second electrode
`power Supply lines 119 and low at peripheral areas near the
`second electrode power supply lines 119.
`0.055 The auxiliary wiring elements 118 may not linearly
`be arranged. As is shown in FIGS. 5C to 5E and FIG. 6C,
`the auxiliary wiring elements 118 may be arranged in a
`ZigZag shape along the peripheries of first electrodes 117.
`0056 Furthermore, as shown in FIG. 5F, the auxiliary
`wiring elements 118 may be formed in stripes within the
`second electrode power supply lines 119. Alternatively, the
`pixels may be varied in size for colors, and the sizes of
`auxiliary wiring elements may be determined in accordance
`with the distance between adjacent first electrodes. Optimal
`patterns may be adopted depending on conditions Such as
`the Screen size and the number of pixels.
`0057 The organic EL display device 1 is of the active
`matrix type wherein the first electrodes 117 are formed in
`independent insular shapes and the Second electrode 122 is
`provided commonly for all the display elements P. Thus,
`auxiliary wiring elements 118 connected between adjacent
`pixels may be provided in the same plane as the first
`electrodes 117.
`0.058. The same plane in this context refers to not only a
`planar plane but also a plane with unevenneSS or Steps. In
`addition, the layer in which the first electrodes 117 are
`formed may partly be formed of different materials in the
`direction of extension of the layer. In short, it refers to the
`Same plane in the thickness direction of the Stacked Struc
`ture.
`0059 Since the auxiliary wiring element 118 with fixed
`potential is provided between adjacent display elements P.
`capacitive coupling between pixels can be Suppressed and
`factors of degradation in display quality, Such as crosstalk,
`can be eliminated. Thus, the display device with high quality
`can be provided.
`0060. In the top-face luminescence type, when the first
`electrode 117 is formed on the TFTs (SW1 and SW2) via an
`insulating layer 116, the display element P can be formed
`over the TFTs (overlapping structure) and wiring under the
`insulating layer 116. Thus, the opening ratio can be deter
`mined irrespective of circuits such as TFTs, and high effi
`ciency of use of light can be achieved.
`0061. In the above-described embodiment, the thin Ba
`film is used as the transparent electrode material of the upper
`electrode (second electrode) 122 of display element P.
`Alternatively, various transparent conductive materials can
`be selectively used. It is desirable to use the material suitable
`for the organic light-emission layer 121. The Second elec
`trode 122 may be formed of a plurality of stacked films, and
`ITO or tin oxide (SnO) may be stacked on a thin film of Ba
`or calcium (Ca). When the second electrode 122 is used as
`an anode, ITO or IZO (indium Zn oxide) with high trans
`parency may be used as a transparent electrode material. It
`is also desirable to choose the material Suitable for the
`organic light-emission layer 121 as the metal material of the
`lower electrode (first electrode) 117 of display element P. It
`is also preferable to choose the material suitable for the
`polarity of the electrode.
`0.062 AS has been described above, according to the
`embodiment, the auxiliary wiring element 118 is electrically
`
`connected to the Second electrode 122. Thus, the resistance
`of the entire light-emission-side electrode can be lowered,
`and non-uniformity in display within the display Screen can
`Sufficiently be Suppressed.
`0063 A method of fabricating the organic EL panel 2 will
`now be described.
`0064. An undercoat layer 102 is formed by depositing an
`SiN film and/or an SiO film on an insulating support
`Substrate 101 of glass, etc. by means of atmospheric-pres
`sure CVD or plasma CVD. An amorphous silicon film is
`deposited on the undercoat layer 102. P-type impurities of
`boron (B), etc. may be doped in the entire surface of the
`Substrate in order to control thresholds of TFTs.
`0065. Then, an excimer laser beam is radiated on the
`amorphous Silicon film to anneal it. Thus, the amorphous
`Silicon layer is crystallized into a polysilicon film. Subse
`quently, the polysilicon film is Subjected to a photolithog
`raphy process comprising a Series of Steps of resist-coating,
`exposure, patterning and etching. Thereby, the polysilicon
`film is formed in insular shapes.
`0066. Thereafter, a silicon oxide (SiOx) film is formed
`over the entire Surface of the Substrate So as to cover the
`polysilicon film, thereby a gate insulating film 103 is
`formed. A MoW film is deposited as a gate metal film on the
`gate insulating film 103. The MoW film is subjected to a
`photolithography process to form a gate electrode 104 of a
`p-type TFT. Furthermore, boron (B) is doped to form a
`Source region 105 and a drain region 106, which are con
`ductive regions, in the polysilicon film of the p-type TFT.
`0067. The MoW gate metal film is then subjected to a
`photolithography process to form a Scan Signal line 107, a
`gate electrode 108 integral with the scan signal line 107, a
`portion 109a of a video signal line 109, and a lower
`electrode pattern 110a of a Video signal Voltage holding
`capacitor 110.
`0068. Using as a mask the gate electrode 108 or the resist
`at the time of forming the gate electrode, phosphorus (P)
`ions are doped from above to form a Source region 111 and
`a drain region 112 in the polysilicon film of an n-type TFT.
`0069. Subsequently, an SiOx film is formed by CVD to
`cover the entire Surface of the Substrate, thereby an inter
`layer insulating film 213 is formed. Then, contact holes are
`formed, which penetrate the interlayer insulating film 213
`and gate insulating film 103 and reach the Source regions
`105 and 111 and the drain regions 106 and 112 of the
`polysilicon film.
`0070. By sputtering, etc., a three-layer metal film com
`prising Mo/Al/Mo in Succession is formed. Then, a photo
`lithography process is performed to form a Source electrode
`113 connected to the source region 105, a drain electrode
`114 connected to the drain region 106, an organic EL current
`supply line 115 integral with the drain electrode 114, and a
`portion 109b of the video signal line 109.
`0071. The portion 109b of the video signal line is elec
`trically connected to the previously formed portion 109a via
`the contact hole, thus constituting the video signal line 109.
`In addition, the portion 109b of the video signal line is
`electrically connected to the drain region 112 of n-type TFT
`(SW1) via the contract hole, thus constituting the drain
`electrode 131. Besides, the source electrode 132 electrically
`
`SAMSUNG EX. 1003 - 12/16
`
`

`

`US 2002/0158835 A1
`
`Oct. 31, 2002
`
`connected to the source region 111 of n-type TFT (SW1) via
`the contact hole is electrically connected to the lower
`electrode pattern 110a of Video signal Voltage holding
`capacitor 110.
`0.072 Thus, the n-type TFTs functioning as the Switching
`elements SW1 and the p-type TFTs functioning as the
`driving control elements SW2 are formed. At the same
`process, the Video signal line drive circuit Xdr and Scan
`Signal line drive circuit Ydr in the drive circuit region, which
`are composed by combining the n-type TFTS and p-type
`TFTs, are formed. In addition, the video signal voltage
`holding capacitor 110 is formed, with the organic EL current
`supply line 115 formed as the upper electrode.
`0073. After an SiNX film is provided by CVD to form an
`insulating layer 116, a contact hole is formed which reaches
`the source electrode 113 of driving control element SW2.
`Subsequently, by Sputtering, etc., a three-layer metal film
`comprising Al/Mo/ITO in Succession is formed. Then, a
`photolithography process is performed to form a light
`reflecting first electrode 117 of display element P, an aux
`iliary wiring element 118, and a Second electrode power
`supply line 119 formed integral with the auxiliary wiring
`element 118 in a rectangular shape Surrounding the display
`region 10.
`0.074 As described above, the auxiliary wiring element
`118 and first electrode 117 are formed in the same step by
`using the Same conductive material. Accordingly, the aux
`iliary wiring element 118 can be formed without providing
`an additional step of forming the auxiliary wiring step 118.
`Moreover, the first electrode 117 of display element P is
`disposed on the insulating layer 116 and connected to the
`Source electrode 113 of driving control element SW2 via the
`insulating layer 116. Thus, the first electrode 117, driving
`control element SW2 and Switching element SW1 can be
`formed in an overlapping Structure, and the area of the first
`electrode 117 can be increased.
`0075 Following the above, a black organic resist mate
`rial is coated on the entire Surface of the Substrate Such that
`the film thickness of the dried resist material may become 3
`tim. Then, a partition wall 120 including regions exposing
`the first electrode 117 and auxiliary wiring element 118 is
`formed by photolithography. Specifically, the partition wall
`120 includes an opening portion 120b exposing the first
`electrode 117 at a position corresponding to the first elec
`trode 117, and a contact portion 120a exposing the auxiliary
`wiring element 118 at a position corresponding to the
`auxiliary wiring element 118.
`0.076 The partition wall 120 is formed so as to surround
`the display element P, and Separates each display element P.
`In order to prevent leak of EL light between adjacent display
`elements, the partition wall 120 should preferably be formed
`of a light-shielding black material. In addition, in order to
`Surely separate each display element P, the partition wall 120
`should preferably have a film thickness equal to or more than
`the film thickness of the