KR100778039B1 - Light emitting apparatus, method of manufacturing light emitting apparatus, and electronic apparatus - Google Patents

Abstract

An object of the present invention is to provide a light emitting device in which stable electrical characteristics are obtained and a method of manufacturing the same.

The pixel electrode 25 is composed of an electrode portion 25a having a plurality of light emitting regions arranged therein, and a connection portion 25b connected to the wiring 12. The pixel electrode 25 of the first unit element Ur is an electrode. The electrode layers 51, 52, and 53 corresponding to the portion 25a and the connection portion 25b are stacked, and the pixel electrode 25 of the second unit element Ug includes an electrode layer corresponding to the electrode portion 25a ( 52, 53 and the electrode layers 51, 52, 53 corresponding to the connection portion 25b are laminated, and the second unit element is larger than the number of stacked layers of the electrode layer in the electrode portion 25a of the first unit element Ur. A light emitting device is used in which the number of electrode layers in the electrode portion 25a of (Ug) is small.

Underlayer, light reflection layer, electrode part, partition wall layer, sealing material

Description

LIGHT EMITTING APPARATUS, METHOD OF MANUFACTURING LIGHT EMITTING APPARATUS, AND ELECTRONIC APPARATUS}

1 is a cross-sectional view showing a configuration of a light emitting device according to a first embodiment of the present invention.

FIG. 2 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1. FIG.

3 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

4 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

5 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

FIG. 6 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1; FIG.

7 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

8 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

9 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1;

FIG. 10 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1; FIG.

FIG. 11 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 1; FIG.

12 is a cross-sectional view illustrating a configuration of a light emitting device according to a contrast example.

FIG. 13 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 12; FIG.

FIG. 14 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 12; FIG.

FIG. 15 is a flowchart for explaining a method of manufacturing the light emitting device shown in FIG. 12; FIG.

16 is a perspective view showing an example of an electronic apparatus according to the present invention;

Explanation of symbols for the main parts of the drawings

10: board 12: wiring

14: base layer 21: light reflection layer

23: protective film 25: first electrode (pixel electrode)

25a: electrode portion 25b: connection portion

31 partition wall 33 light emitting body

35 second electrode (semi-transmissive reflective layer) 37 sealing material

51, 251: first electrode layer (electrode layer) 52, 252: second electrode layer (electrode layer)

53, 253: Third electrode layer (electrode layer) 1004: EL device

D: stepped portion

H, Hr, Hg, Hb, HR, HG, HB: Contact Hole

U: unit element Ur: unit element (first unit element)

Ug: unit element (second unit element) Ub: unit element (third unit element)

R, G, B: light emitting area

The present invention relates to a light emitting device, a manufacturing method of the light emitting device, and an electronic device.

DESCRIPTION OF RELATED ART Conventionally, the light emitting device by which the element (henceforth a "unit element") which interposed between the 1st electrode and the 2nd electrode the light emitting layer which consists of light emitting materials, such as organic electroluminescent (EL) material, is arrange | positioned on a board | substrate It is proposed. In such a light emitting device, since the peak width of the spectrum of the emitted light by the light emitting layer is wide and its intensity is low, for example, when it is employed as a display device, it is difficult to secure sufficient color reproducibility.

In order to solve this problem, for example, Patent Document 1 discloses a configuration in which each unit element has a resonator structure for resonating the light emitted from the light emitting layer. In this configuration, a light reflection layer (dielectric mirror) is disposed between the light transmissive first electrode positioned on the substrate side and the substrate. The emitted light from the light emitting layer is reciprocated between the light reflecting layer and the second electrode which face each other with the light emitting layer interposed therebetween. Then, the light of the resonant wavelength according to the optical distance between the light reflection layer and the second electrode is selectively amplified and then emitted to the observation side. Therefore, light having a narrow peak width and high intensity can be used for display. Therefore, it becomes possible to improve the color reproducibility of the display device. Further, by adjusting the optical distance between the light reflection layer and the second electrode for each unit element, light having a wavelength corresponding to a plurality of colors (for example, red, green, or blue) can be taken out.

Further, as a light emitting device in which the resonator structure is formed in each unit element, a first electrode having three kinds of thicknesses corresponding to RGB (red, green, blue), respectively, is proposed between the light reflection layer and the second electrode. In such a light emitting device, a film is first formed from a thick unit element in order, and the first pattern is formed by repeating patterning until the film becomes a predetermined thickness corresponding to each of the RGB. An electrode is formed.

[Patent Document 1] International Publication No. 01/039554 Pamphlet

However, when a first electrode having a predetermined thickness corresponding to each of RGB is formed by the method of repeating such patterning, whether or not the film formed on the unit element is etched away according to the required thickness of the first electrode. Is determined. Therefore, the contact hole constituting the unit element having a thin thickness of the first electrode is exposed to the etchant during the patterning of the first electrode of the thick unit element, which may cause a problem in the electrical characteristics of the light emitting device. .

This invention is devised in view of such a situation, Comprising: It makes it a subject to provide the light-emitting device by which stable electrical characteristic is obtained, and its manufacturing method.

MEANS TO SOLVE THE PROBLEM In order to solve this subject, the light emitting device which concerns on this invention is a light reflection layer, a semi-transmissive reflection layer, the light-emitting layer arrange | positioned between the said light reflection layer, and the said semi-transmissive reflection layer on a board | substrate, the said light reflection layer, and the said semi-reflection A plurality of unit elements including a light-transmitting pixel electrode disposed between the transmission reflection layer, a resonator structure is formed in the light emitting region of each unit element, the first unit element and the first unit of the plurality of unit elements A light emitting device comprising a device and a second unit device having a different resonant wavelength in the resonator structure, wherein the pixel electrode is composed of an electrode portion disposed in the light emitting region and a connection portion connected to a wiring; The pixel electrode of the unit element is formed by stacking a plurality of electrode layers corresponding to the electrode portion and the connection portion, wherein the pixel electrode of the second unit element is at least The electrode layer corresponding to the base electrode portion and the connecting portion and the electrode layer corresponding to the connecting portion are laminated, and the electrode portion of the second unit element is larger than the number of stacked layers of the electrode layer in the electrode portion of the first unit element. It is characterized in that the number of lamination of the electrode layer in.

In such a light emitting device, an electrode layer serving as a pixel electrode of a first unit element is smaller than that of the electrode layer of the second unit element than that of the electrode layer of the first unit element. By the first patterning at the time of forming the electrode, the electrode layer corresponding to the electrode portion of the second unit element is removed. However, in the light emitting device of the present invention, since the pixel electrode of the second unit element is formed by stacking an electrode layer corresponding to the electrode portion and the connecting portion and an electrode layer corresponding to the connecting portion, the pixel electrode of the first unit element. When patterning the electrode layer constituting the electrode, it is not necessary to remove the electrode layer corresponding to the connecting portion of the second unit element. Therefore, in the process of manufacturing the light emitting device of the present invention, the surface on the substrate side of the connecting portion is not exposed to the etching liquid used for patterning the electrode layer. For example, when the contact hole which exposes wiring is formed in the surface of the board | substrate side of a connection part, a contact hole is not exposed to the etching liquid used for patterning of an electrode layer. Therefore, in the light emitting device of the present invention, the etching solution used for patterning the electrode layer is effectively prevented from disturbing the electrical characteristics of the light emitting device.

In the light emitting device of the present invention, the pixel electrode of the second unit element is formed by stacking an electrode layer corresponding to the electrode portion and the connecting portion and an electrode layer corresponding to the connecting portion, so that the connecting portion of the second unit element is connected. A plurality of electrode layers are formed therein. Therefore, the reliability in the electrical connection of a connection part and wiring becomes high, and the stable electrical characteristic is acquired.

On the other hand, for example, when only one electrode layer is formed in the connection portion, disconnection tends to occur at the connection portion between the wiring and the pixel electrode, and the reliability in the electrical connection between the wiring and the pixel electrode is low. You lose.

In the light emitting device of the present invention, the first unit element, the second unit element, and the third unit element having different number of stacks of electrode layers corresponding to the electrode portion and having different resonant wavelengths in the resonator structure are provided. It can be done.

By setting it as such a light-emitting device, the 1st unit element, the 2nd unit element, and the 3rd unit element can extract light of the wavelength corresponding to RGB, respectively, and the stable electrical characteristic is acquired and it is excellent in color reproducibility. A light emitting device of color can be realized.

In the light emitting device of the present invention, the number of stacked layers of the electrode layers corresponding to the connecting portions can be the same in all the unit elements.

In such a light emitting device, the electrical resistance when the wiring and the pixel electrode are electrically connected is uniform as compared with the case where a unit element having a different number of stacking of electrode layers corresponding to the connection part is included, thereby stabilizing electrical characteristics of the light emitting device. Can be.

In the light emitting device of the present invention, the pixel electrode may cover the stepped portion existing on the substrate side of the pixel electrode.

By setting it as such a light emitting device, it is effective that the etching liquid used for patterning the electrode layer covering the stepped portion penetrates into the substrate side of the electrode layer from the stepped portion present on the substrate side of the electrode, thereby causing a problem in the characteristics of the light emitting device. You can prevent it.

In the light emitting device of the present invention, the light reflection layer may be disposed on the side opposite to the substrate of the light reflection layer, and a protective film having light transparency may be disposed.

When the etching liquid used for patterning an electrode layer adheres to a light reflection layer, the surface of a light reflection layer will be damaged (corrosion). As a material of the light reflection layer, materials such as aluminum and silver are suitably employed, but since such materials have low corrosion resistance, damage and deterioration due to the etching solution are particularly remarkable. And when the reflection characteristic (for example, reflectance) of a light reflection layer deteriorates because a light reflection layer is damaged, the resonance efficiency by a resonator structure will fall.

On the other hand, by setting it as the light emitting device in which the protective film which covers the said light reflection layer is arrange | positioned on the opposite side to the said board | substrate of the said light reflection layer, it can effectively prevent that the etching liquid used for patterning of an electrode layer adheres to a light reflection layer.

The manufacturing method of the light emitting device which concerns on this invention is a method of manufacturing the light emitting device of Claim 1, Comprising: It respond | corresponds to the said electrode part and the said connection part of a said 1st unit element, and corresponds to the said connection part of a said 2nd unit element. A first electrode layer forming step of forming a first electrode layer, and a second electrode layer forming step of forming a second electrode layer corresponding to the electrode portion and the connecting portion of the first unit element and the second unit element. It features.

According to the manufacturing method of the light emitting device of the present invention, when patterning the first electrode layer and the second electrode layer, the electrode layer serving as the connecting portion is not etched, and the surface of the substrate side of the connecting portion is patterned in the process of manufacturing the light emitting device. It is not exposed to the etchant used for the process.

In addition, according to the manufacturing method of the light emitting device of the present invention, two electrode layers of the first electrode layer and the second electrode layer are formed in the electrode portion of the first unit element by performing the first electrode layer forming step and the second electrode layer forming step. The second electrode layer is formed on the electrode portion of the second unit element, and two electrode layers of the first electrode layer and the second electrode layer are formed on the connection portion between the first unit element and the second unit element. Therefore, according to the manufacturing method of the light-emitting device of this invention, it can form that the number of laminated layers of the electrode layer which comprises an electrode part in a 1st unit element and a 2nd unit element differs. In addition, according to the manufacturing method of the light emitting device of the present invention, since two electrode layers are formed in the connecting portion in the first unit element and the second unit element, disconnection of the electrode layer is unlikely to occur, so that the electrical connection between the wiring and the pixel electrode is performed. The reliability of becomes high.

In the method of manufacturing the light emitting device, in the first electrode layer forming step, an electrode layer corresponding to the connecting portion of the third unit element different from the first unit element and the second unit element is formed by the first electrode layer, In the second electrode layer forming step, an electrode layer corresponding to the connecting portion of the third unit element is formed by the second electrode layer, and after the second electrode layer forming step, the first unit element and the second unit element And a third electrode layer forming step of forming a third electrode layer corresponding to the electrode portion and the connecting portion of the third unit element.

According to this manufacturing method, three electrode layers of the first electrode layer, the second electrode layer, and the third electrode layer are formed in the electrode portion of the first unit element, and the second electrode layer and the third electrode layer of the electrode portion of the second unit element are formed. Two electrode layers are formed, and a third electrode layer is formed on the electrode portion of the third unit element, and at the same time, the first electrode layer, the second electrode layer, and the first unit element, the second unit element, and the third unit element are connected to each other. Three electrode layers of the three electrode layers are formed. Therefore, disconnection of the electrode layer at the connecting portion is less likely to occur, and the reliability in the electrical connection between the wiring and the pixel electrode becomes very high.

In addition, according to such a manufacturing method, for example, the first unit element, the second unit element, and the third unit element can be made to extract light having a wavelength corresponding to RGB, respectively, and stable electrical characteristics can be obtained, resulting in color. The light emitting device of color excellent in reproducibility can be manufactured.

In the manufacturing method of the said light-emitting device, it can be set as the manufacturing method which forms a 1st electrode layer so that the step part on the to-be-formed surface which forms a said 1st electrode layer may cover at the said 1st electrode layer formation process.

According to this manufacturing method, it is possible to effectively prevent the etching liquid used for patterning the electrode layer from penetrating into the substrate side of the electrode layer from the stepped portion on the surface to be formed which forms the first electrode layer, thereby impairing the characteristics of the light emitting device. Can be.

In the manufacturing method of the said light-emitting device, it can be set as the manufacturing method which forms a 2nd electrode layer on the said 1st electrode layer so that the part corresponding to the said step part may be covered.

According to such a manufacturing method, intrusion of etching liquid can be prevented more effectively than when the stepped part on the to-be-formed surface is covered only by a 1st electrode layer.

In the manufacturing method of the said light-emitting device, it can be set as the manufacturing method including the process of forming the said light reflection layer before the said electrode formation process, and the protective film formation process which covers the said light reflection layer and forms the protective film which has a light transmittance.

According to such a manufacturing method, the etching liquid used for patterning of an electrode layer can be prevented from adhering to a light reflection layer.

An electronic device of the present invention includes the light emitting device according to any one of the above.

According to such an electronic device, the light-emitting device which has high reliability in the electrical connection of a wiring and a pixel electrode, and acquires stable electrical characteristics is provided.

Hereinafter, an embodiment in the case where the light emitting device of the present invention is applied to an EL device which is an example of a light emitting device will be described as an example. In addition, in the following description, although various structures are illustrated using drawing, the structure shown in these drawings may show different dimensions with respect to actual structure, in order to show a characteristic part easily.

<Light emitting device>

First, an EL device according to an embodiment of a light emitting device will be described.

1 is a sectional view showing the structure of an EL device according to the present embodiment. In the EL device shown in Fig. 1, a plurality of unit elements U (Ur, Ug, Ub) arranged in a matrix form are sealed on the surface of the substrate 10 by a sealing material 37. Each unit element U is an element which generates light of a wavelength corresponding to any one of red, green, and blue, and has a different resonant wavelength in the resonator structure. That is, the unit element Ur (first unit element) emits red light, the unit element Ug (second unit element) emits green light, and the unit element Ub (third unit element) Emits blue light.

The EL device in this embodiment is a top emission type in which light generated by each unit element U is emitted toward the side opposite to the substrate 10. Therefore, as the board | substrate 10, in addition to the board | plate material which has light transmittance, such as glass, opaque board | plate materials, such as ceramics and a metal sheet, can be employ | adopted.

As shown in FIG. 1, a plurality of wirings 12 are formed on the surface of the substrate 10. The wiring 12 is, for example, a data line or a scanning line for transmitting a signal for driving each unit element U.

In addition, the surface of the board | substrate 10 in which each wiring 12 was formed is covered by the base layer 14. The base layer 14 is a film body formed of various insulating materials such as resin materials such as acrylic or epoxy or inorganic materials such as silicon oxide (SiOx) and silicon nitride (SiNx).

On the surface of the base layer 14, the light reflection layer 21 is formed so as to correspond to each unit element U. The light reflection layer 21 in this embodiment is formed in a stripe shape so as to follow the arrangement of the unit elements U. Each light reflection layer 21 is made of a material having light reflection. Specifically, as the material for forming the light reflection layer 21, various materials such as a single metal such as aluminum or silver, or an alloy containing aluminum or silver as a main component are used.

The surface of the base layer 14 on which the light reflection layer 21 is formed is covered by a protective layer 23 which is continuously distributed over the plurality of unit elements U. As shown in FIG. The protective layer 23 is for protecting the etching solution used for patterning the electrode layer, which will be described later, from adhering to the light reflection layer 21. For example, the protective layer 23 is insulated with light transmittance such as silicon oxide (SiOx) or silicon nitride (SiNx). It is formed by the material.

In addition, as shown in FIG. 1, the contact penetrates the protective layer 23 and the base layer 14 in respective thickness directions at positions overlapping the wiring 12 when viewed in a direction perpendicular to the surface of the substrate 10. Holes H (Hr, Hg, Hb) are formed for each unit element U. That is, the contact hole Hr is the unit element Ub that emits red light, the contact hole Hg is the unit element Ug that emits green light, and the contact hole Hb is the unit element Ub that emits blue light. ) Is installed.

On the surface of the substrate 10 on which the protective layer 23 is formed, the electrode portion 25a disposed in the light emitting region RGB overlapping the light emitting body 33 in plan view, and the contact hole H, are disposed on the contact hole H. The 1st electrode 25 (pixel electrode) comprised from the connection part 25b connected to the wiring for receiving and connecting the electric charge connected to the exterior through (H) is formed. As shown in FIG. 1, the first electrode 25 is formed so as to cover the stepped portion D existing on the substrate 10 side of the first electrode 25, and for each unit element U. FIG. They are formed apart from each other. In the present embodiment, the number of layers of the electrode layers of the electrode portions 25a differs for each color of light emitted from the unit element U.

More specifically, on the surface of the substrate 10 on which the protective layer 23 is formed, the contact hole H and the light reflection layer 21 of the unit element Ur that emits red light among the unit elements U are covered. The first electrode layer 51 is formed. In addition, the second electrode layer 52 is formed so as to cover the first electrode layer formation region where the first electrode layer 51 is formed and the light reflection layer 21 of the unit element Ug that emits green light, and the second electrode layer 52. The third electrode layer 53 is formed to cover the light emitting layer 21 of the unit element Ub that emits blue light and the second electrode layer formation region where the () is formed. Each of the first electrode layer 51, the second electrode layer 52, and the third electrode layer 53 is formed of a light transmissive conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

Therefore, as shown in FIG. 1, the first electrode 25 of the unit element Ur emitting red light has the first electrode layer 51 and the second electrode layer (corresponding to the electrode portion 25a and the connecting portion 25b). 52 and three electrode layers of the third electrode layer 53 are stacked, and the first electrode 25 of the unit element Ug emitting green light is the first electrode layer 51 corresponding to the connection portion 25b. And two electrode layers of the second electrode layer 52 and the third electrode layer 53 corresponding to the electrode portion 25a and the connection portion 25b are laminated, and the first of the unit element Ub emitting blue light is emitted. The electrode 25 is formed by stacking a first electrode layer 51 and a second electrode layer 52 corresponding to the connecting portion 25b and a third electrode layer 53 corresponding to the electrode portion 25a and the connecting portion 25b. All.

As shown in FIG. 1, the first electrode layer 51, the second electrode layer 52, and the third electrode layer 53, which are all electrode layers constituting the first electrode 25, are stacked on each contact hole H. The number of layers of the electrode layers corresponding to the connection portions 25b of the first electrodes 25 is the same in all the unit elements U. In addition, the first electrode layer 51 enters the contact hole H to be in contact with the wiring 12, and the first electrode layer 51, the second electrode layer 52, and the third electrode layer 53 are connected to the wiring 12. Is electrically connected).

The partition layer 31 is formed on the surface of the substrate 10 on which the first electrode 25 is formed. The partition layer 31 is a partition wall formed in a lattice shape so as to partition a space on the surface of the substrate 10 for each unit element U. The partition layer 31 is formed of various insulating materials such as a resin material such as acrylic or epoxy or an inorganic material such as silicon oxide or silicon nitride.

A light emitter 33 is formed for each unit element U in a space surrounded by an inner wall of the partition layer 31 and having the first electrode 25 as a bottom surface. The light emitting body 33 has the structure which laminated | stacked the some functional layer containing the light emitting layer which consists of organic electroluminescent material. The light emitter 33 of each unit element U includes a light emitting layer that emits light of a wavelength corresponding to the unit element U. The first electrode 25 of each unit element U functions as an anode for imparting electrical energy to the light emitter 33. On the other hand, on the surface of each light emitter 33, a second electrode 35 serving as a cathode of the light emitter 33 is formed. However, the first electrode 25 may function as a cathode and the second electrode 35 may function as an anode.

The light emitter 33 in this embodiment has a structure in which three kinds of functional layers, a hole transporting layer, a light emitting layer, and an electron transporting layer, are stacked in this order from the substrate 10 side toward the second electrode 35 side. However, the structure of the light emitter 33 is not limited to this example. For example, the structure may be a structure in which a hole injection layer is interposed between the hole transport layer and the first electrode 25, or a structure in which an electron injection layer is interposed between the electron transport layer and the second electrode 35. In other words, the light emitting layer may be interposed between the first electrode 25 and the second electrode 35.

The second electrode 35 (semi-transmissive reflective layer) functions as a semi-transmissive reflective layer having the property of transmitting part of the light reaching the surface and reflecting the rest. The second electrode 35 in this embodiment is formed of a material having light transmittance such as indium tin oxide (ITO). Even when the second electrode 35 is made of a light transmissive material as described above, when the sealing material 37 is formed of a material having a lower refractive index than the second electrode 35, the second electrode 35 and the sealing material 37 Since part of the light is transmitted at the interface and the other part is reflected, the second electrode 35 can function as a semi-transmissive reflective layer. Further, even when a light reflective material such as aluminum or silver (or an alloy containing these metals as a main component) is thinly formed as the second electrode 35, the second electrode 35 can function as a semi-transmissive reflective layer. .

Each unit element U is an element including a light reflection layer 21, a first electrode 25, a light emitter 33, and a second electrode 35. In each unit element U, a resonator structure for resonating the light emitted from the light emitting layer is formed between the light reflection layer 21 and the second electrode 35. That is, after the light emitted by the light emitting layer of the light emitter 33 reciprocates between the light reflection layer 21 and the second electrode 35, only the components of the resonant wavelength in the resonator structure are selectively amplified, and thus the second electrode 35 ) Is transmitted through and is emitted to the observation side (upper side in FIG. 1). Therefore, according to this embodiment, light having a narrow peak width and high intensity can be used for display.

For example, assuming that the refractive index and the film thickness of the light emitter 33 are approximately the same regardless of the light emission color of each unit element U, the surface of the light reflection layer 21 facing the light emitter 33 and the light emitter 33 The resonant wavelength is determined in accordance with the optical distance between the surfaces opposing the light reflection layer 21. The optical distance between the light reflection layer 21 and the light emitter 33 in this embodiment is determined by the light emission color of the unit element U depending on the film thickness (the number of stacked layers) of the first electrode 25 as described below. Each is determined individually.

As described with reference to FIG. 1, the first electrode layer 51 and the second electrode layer 52 of the first electrode 25 are disposed between the light reflection layer 21 and the light emitter 33 in the red unit element Ur. The third electrode layer 53 and the protective film 23 are interposed. In addition, the second electrode layer 52, the third electrode layer 53, and the protective film 23 of the first electrode 25 are interposed between the light reflection layer 21 and the light emitter 33 of the green unit element Ug. do. In addition, a third electrode layer 53 and a protective film 23 of the first electrode 25 are interposed between the light reflection layer 21 and the light emitter 33 of the blue unit element Ub.

In addition, if the first electrode 25 is formed of ITO (Indium Tin Oxide) and the protective film 23 is formed of silicon nitride having the refractive index substantially the same as that of the first electrode 25, light The optical distance between the reflective layer 21 and the light emitter 33 is proportional to the geometric distance between the two. That is, in this embodiment, the resonant wavelength of the unit element Ur is longer than the resonant wavelength of the unit element Ug, and the resonant wavelength of the unit element Ug is longer than the resonant wavelength of the unit element Ub. The resonator structure of the unit element U is determined according to the film thickness of the first electrode 25 and the film thickness of the protective film 23.

<Method of manufacturing light emitting device>

Next, a method of manufacturing the EL device of this embodiment shown in FIG. 1 will be described with reference to FIGS. 2 to 11. In addition, each layer shown below is formed by various well-known film-forming techniques, such as sputtering, chemical vapor deposition (CVD), and vapor deposition. In addition, for example, photolithography and etching techniques are used for patterning each layer.

First, as shown in FIG. 2, a plurality of wirings 12 are formed at predetermined positions on the surface of the substrate 10. Next, the film | membrane which becomes the base layer 14 is formed over the whole surface on the surface of the board | substrate 10, and is patterned, and the base layer 14 is formed as shown in FIG. Next, a light reflective conductive film is formed over the entire surface of the substrate 10, and the light reflective layer 21 is formed as shown in FIG. 4 by patterning the conductive film.

In addition, an insulating film having light transparency is formed over the entire surface of the substrate 10, and by patterning the insulating film, a protective film 23 covering the light reflection layer 21 is formed as shown in FIG. 5 (protective film forming step). On the obtained protective film 23, a stepped portion D attributable to the thickness of the light reflection layer 21 is formed in a region covering the edge of the light reflection layer 21. In this embodiment, in this protective film forming step, as shown in FIG. 5, a portion of the insulating film overlapping the wiring 12 is removed to form a hole h in which the wiring, which becomes the contact hole H, is exposed. .

Next, the first electrode 25 (pixel electrode) is formed on the light reflection layer. First, a conductive film serving as the first electrode layer 51 of the first electrode 25 is formed over the entire surface of the substrate 10. Since the material of this conductive film is filled in the hole h which becomes all the contact holes H, the contact hole H which the 1st electrode layer 51 and the wiring 12 connect is formed. Then, as the conductive film serving as the first electrode layer 51 is patterned, as shown in FIG. 6, the light reflection layer of all of the contact holes H and the unit element Ur emitting red light among the unit elements U is shown. (1) The 1st electrode layer 51 is formed so that the step part D which exists on the protective film 23 (formation surface) used as the lower layer of the 1st electrode layer 51 may be formed (1st electrode layer formation process). . Therefore, in the first electrode layer forming step, as shown in FIG. 6, the green light is emitted while corresponding to the electrode portion 25a and the connecting portion 25b of the unit element Ur that emits red light among the unit elements U. The first electrode layer 51 corresponding to the connecting portion 25b of the unit element Ug and the unit element Ub that emits blue light is formed.

Next, the conductive film which becomes the 2nd electrode layer 52 of the 1st electrode 25 is formed over the whole surface of the board | substrate 10, and this conductive film is patterned, and as shown in FIG. 7, the 1st electrode layer 51 is shown in FIG. The second electrode layer 52 is formed so as to cover the formed first electrode layer formation region and the light reflection layer 21 of the unit element Ug that emits green light (second electrode layer forming step). Therefore, in the second electrode layer forming step, as shown in FIG. 7, the electrode unit 25a and the connection unit 25b of the unit element Ur emitting red light and the unit element Ug emitting green light are simultaneously supported. The second electrode layer 52 is formed on the first electrode layer 51 corresponding to the connection portion 25b and the step portion D of the unit element Ub that emits blue light.

Subsequently, the conductive film which becomes the 3rd electrode layer 53 of the 1st electrode 25 is formed over the whole surface of the board | substrate 10, and this conductive film is patterned, and as shown in FIG. 8, the 2nd electrode layer 52 will be The third electrode layer 53 is formed to cover the formed second electrode layer formation region and the light reflection layer 21 of the unit element Ub that emits blue light (third electrode layer forming step). Therefore, in the 3rd electrode layer formation process, as shown in FIG. 8, the 3rd electrode layer 53 corresponding to the electrode part 25a and the connection part 25b of all the unit elements U is formed.

Subsequently, as shown in FIG. 9, the partition layer 31 is formed by formation and patterning of the resin film. In addition, as shown in FIG. 10, in the space of each unit element U partitioned by the partition layer 31, the light emitter 33 including the light emitting layer of the emission color corresponding to the unit element U is sequentially formed. Is formed. Subsequently, as shown in FIG. 11, the semi-transmissive second electrode 35 is formed to face the first electrode 25 with each light emitter 33 therebetween, and the sealing material to cover the entire surface of the substrate 10. 37 is provided (see FIG. 1).

Here, the effects of the EL device of the present embodiment described above will be described in detail with reference to the following.

12 is an EL device according to a comparative example, and FIGS. 13 to 15 are process drawings of the manufacturing method of the EL device shown in FIG. In the EL device shown in FIG. 12, similarly to the EL device shown in FIG. 1, after the light reflection layers 21 of all the unit elements U are covered by a single protective film 23, the film of the first electrode 25 is covered. The thickness (the number of stacked layers) is individually selected for each color of light emitted from the unit elements U.

12 differs from the EL device shown in FIG. 1 in that all the electrode layers constituting the first electrode 25 are formed on all the contact holes H in the EL device shown in FIG. In the EL device shown in Fig. 12, only a part of the electrode layers constituting the first electrode are stacked on the contact holes HG and HB of the unit element Ug that emits green light and the unit element Ub that emits blue light. Specifically, on the contact hole HG of the unit element Ug that emits green light, among the three electrode layers of the first electrode layer 251, the second electrode layer 252, and the third electrode layer 253 of the first electrode. Similarly to the light reflection layer 21, only two layers of the second electrode layer 252 and the third electrode layer 253 are formed. Further, only one layer of the third electrode layer 253 is formed on the contact hole HB of the unit element Ub that emits blue light, similarly to the light reflection layer 21.

Incidentally, in the method of manufacturing the EL device shown in Fig. 12, since the only step different from the method of manufacturing the EL device shown in Fig. 1 is the step of forming the first electrode, only the step of forming the first electrode will be described below. To explain.

First, a conductive film serving as the first electrode layer 251 of the first electrode is formed over the entire surface of the substrate 10 shown in FIG. 5. The material of this conductive film is filled in the hole h which becomes all the contact holes H. As shown in FIG. Then, as the conductive film serving as the first electrode layer 251 is patterned, as shown in FIG. 13, only on the contact hole HR of the unit element Ur emitting the red light and on the light reflection layer 21 of the unit element Ur. The first electrode layer 251 is formed to cover.

Next, a conductive film serving as the second electrode layer 252 of the first electrode is formed over the entire surface of the substrate 10. The material of this electrically conductive film is filled in the hole h used as the contact hole HG and the contact hole HB. By patterning this conductive film, as shown in FIG. 14, on the 1st electrode layer formation area in which the 1st electrode layer 251 was formed, on the contact hole HG of the unit element Ug which emits green light, and the unit element Ug. The second electrode layer 252 is formed so as to cover the light reflection layer 21.

Subsequently, a conductive film serving as the third electrode layer 253 of the first electrode is formed over the entire surface of the substrate 10, and the conductive film is patterned, so that the second electrode layer 252 is formed as shown in FIG. 15. The third electrode layer 253 is formed to cover the electrode layer formation region, the contact hole HB of the unit element Ub that emits blue light, and the light reflection layer 21 of the unit element Ub.

When manufacturing the EL device shown in FIG. 12 by the above-mentioned method, in the process of forming the 1st electrode layer 251, the contact of the unit element Ug which emits green light, and the unit element Ub which emits blue light is contacted. The conductive film which becomes the 1st electrode layer 251 once filled in the hole h used as the hole H is removed by patterning. Therefore, the inside of the hole h serving as the contact hole HG and the contact hole HB is exposed to an etchant used for patterning the conductive film serving as the first electrode layer 251.

In the process of forming the second electrode layer 252, the conductive film made of the second electrode layer 252 once filled in the hole h, which becomes the contact hole HB of the unit element Ub that emits blue light, is formed. It is removed by patterning. Therefore, the inside of the hole h serving as the contact hole HB is exposed to the etching liquid used for patterning the conductive film serving as the second electrode layer 252.

On the other hand, when manufacturing the EL apparatus shown in FIG. 1, in the above-mentioned first electrode layer forming step, the conductive film serving as the first electrode layer 51 formed on the contact hole H is not removed by patterning. Therefore, the hole h serving as the contact hole H is not exposed to the etching liquid used for patterning the conductive film serving as the first electrode layer 51.

In addition, when manufacturing the EL apparatus shown in FIG. 1, in the 1st electrode layer formation process, the 1st electrode layer 51 corresponding to the connection part 25b of all the unit elements U is formed, and all the contact holes H Since the material of the conductive film used as the first electrode layer 51 is filled in the inside), the contact hole H is used in the etching liquid used for patterning not only in the first electrode layer forming step but also in the second electrode layer forming step and the third electrode layer forming step. The hole h which becomes) is not exposed. Therefore, according to the present embodiment, it is possible to effectively prevent deterioration of the contact hole H due to adhesion of the etchant used when forming the first electrode 25.

Further, in the EL device of this embodiment, all the electrode layers constituting the first electrode 25 are stacked on the contact hole H, so that the same number of stacks as those of the light emitting region on each contact hole, as in the EL device shown in FIG. The wiring 12 and the first electrode 25 are electrically connected to each other in the unit elements of the light-emitting device, such as when the electrode layers of the light emitting device are stacked. The electrical resistance at the time of connection becomes uniform, and the electrical characteristics of an EL device can be stabilized.

In addition, as in the EL device shown in FIG. 12, when only one electrode layer made of the third electrode layer 253 is formed on the contact hole HB of the unit element Ub that emits blue light, the EL shown in FIG. Compared with the contact hole H of the unit element U in the apparatus, an electrode layer disconnection on the contact hole H is likely to occur, and the electrical connection between the wiring 12 and the first electrode through the contact hole H is performed. The reliability at is lowered.

In the present embodiment, when the first electrode layer forming step is performed, since the light reflection layer 21 is covered with the protective film 23, the unit element Ug for emitting green light or the unit element Ub for emitting blue light is emitted. The etching liquid is not attached to the light reflection layer 21 of the unit element Ug or the unit element Ub when removing the conductive film serving as the first electrode layer 51 which is planarly overlapped with the light reflection layer 21. . In addition, in this embodiment, since the light reflection layer 21 is covered by the protective film 23, when performing the 2nd electrode layer formation process, it is planarly connected with the light reflection layer 21 of the unit element Ub which emits blue light. Even when the conductive film serving as the overlapping second electrode layer 52 is removed, the etching solution is not attached to the light reflection layer 21 of the unit element Ub. Therefore, deterioration of each light reflection layer 21 due to adhesion of the etching liquid used in the first electrode layer forming step and the second electrode layer forming step can be effectively prevented.

In addition, even when the protective film 23 covering the light reflection layer 21 is disposed, the stepped portion D formed on the protective film 23 tends to be defective, and the first electrode 25 is formed from the stepped portion D. The etching liquid used for patterning of the metal may invade and deteriorate the light reflection layer 21. On the other hand, in the present embodiment, since the first electrode layer 51 is formed so as to cover the stepped portion D existing on the protective film 23, defects due to the step of the protective film 23 can be prevented. This makes it possible to more effectively prevent the disturbance in the characteristics of the EL device.

<Variation example>

In addition, various modifications may be made to the above-described embodiment. Illustrative specific examples are as follows. Moreover, each of the following forms can also be combined suitably.

(1) In the above-described embodiment, the protective film 23 covering the light reflection layer 21 is formed as an example, but the protective film 23 may not be provided.

(2) Although the above-described embodiment exemplifies a configuration in which the elements constituting the light emitting colors of the unit elements U are spaced apart from each other, each element may be continuous over the light emitting color unit elements U. For example, at least one functional layer or the second electrode 35 of the light emitter 33 may be configured to be continuously distributed over all the unit elements U. Even if the light emitting layer is configured to be continuous over all the unit elements U, it is possible to make the emission color of each unit element U different by appropriately selecting the resonance wavelength of each unit element. In addition, the light reflection layer 21 in 1st Example can also be set as the structure distributed continuously over all the unit elements U. As shown in FIG.

(3) Although the above-mentioned embodiment exemplifies a configuration in which the second electrode 35 serves as the transflective reflective layer of the resonator structure, the transflective reflective layer may be formed separately from the second electrode 35. . The semi-transmissive reflective layer in this configuration may be provided on the light emitter 33 side with respect to the second electrode 35, or may be disposed on the opposite side (observation side).

(4) In the above-described embodiment, the color filter (red, green, and blue) corresponding to the emission color of each unit element U may be provided. As a color filter, the thing in which the various color filter was formed in the surface of the board | plate material which has light transmittance can be illustrated. The color filter corresponding to each unit element U is a means which selectively transmits the light of the wavelength corresponding to the resonance wavelength of the unit element U. As shown in FIG. For example, the color filter which permeate | transmits the light corresponding to red is provided in the observation side of the red unit element Ur. According to this structure, since only the component which permeate | transmitted the color filter out of the light emitted from each unit element U is emitted to an observation side, color reproducibility can be improved rather than the structure which is not provided with a color filter. In addition, since external light is absorbed by each color filter, there is an advantage that the reflection of external light is reduced.

(5) The material of each part which comprises a light emitting device, and the method of manufacturing each are arbitrarily changed. For example, although the light emitting layer which consists of organic electroluminescent material was illustrated in the above-mentioned embodiment, the present invention is equally applicable to the light emitting device which includes the light emitting layer which consists of inorganic electroluminescent material, or the light emitting device which used the light emitting diode as a light emitting body. Can be.

<Electronic device>

Next, an electronic device using the light emitting device according to the present invention will be described.

FIG. 16 shows a configuration of a mobile phone employing the EL device shown in FIG. 1 as a display device. The cellular phone 1000 includes a plurality of operation buttons 1001, a scroll button 1002, and an EL device 1004 as a display device.

As the electronic apparatus to which the light emitting device according to the present invention is applied, in addition to the personal computer, digital still camera, television, video camera, car navigation device, small pager, electronic notebook, and electronic paper, as shown in FIG. And electronic calculators, word processors, workstations, television phones, POS terminals, printers, scanners, copiers, video players, and devices with touch panels.

In addition, the use of the light emitting device according to the present invention is not limited to display of an image. For example, it is also possible to use the light-emitting device of this invention as a backlight of a liquid crystal panel.

As described above, according to the present invention, it is possible to provide a light emitting device in which stable electrical characteristics are obtained and a manufacturing method thereof.

Claims (11)

A plurality of light transmissive layers comprising a light reflecting layer, a semi-transmissive reflecting layer, a light emitting layer disposed between the light reflecting layer and the transflective reflecting layer, and a light transmissive pixel electrode disposed between the light reflecting layer and the transflective reflecting layer on the substrate. Having a unit element, A resonator structure is formed in the light emitting region of each unit element, and the light emitting device includes a first unit element among the plurality of unit elements, and a second unit element having a different resonant wavelength in the first unit element and the resonator structure. In The pixel electrode is composed of an electrode portion disposed in the light emitting region and a connection portion connected to a wiring, The pixel electrode of the first unit device is formed by stacking a plurality of electrode layers corresponding to the electrode portion and the connection portion, The pixel electrode of the second unit element is formed by stacking at least an electrode layer corresponding to the electrode portion and the connecting portion and an electrode layer corresponding to the connecting portion, And a stacking number of the electrode layers in the electrode portion of the second unit element is smaller than a stacking number of the electrode layers in the electrode portion of the first unit element. The method of claim 1, And a third unit element having a different number of stacks of the electrode layers corresponding to the first unit element, the second unit element, and the electrode unit, and having a different resonant wavelength in the resonator structure. The method according to claim 1 or 2, And a stacking number of electrode layers corresponding to the connecting portion is the same in all unit elements. The method of claim 1, And the pixel electrode covers a stepped portion present on the substrate side of the pixel electrode. The method of claim 1, A light-emitting device covering the light reflection layer on the side opposite to the substrate of the light reflection layer, and having a light transmissive protective film. As a method of manufacturing the light emitting device according to claim 1, A first electrode layer forming step of forming a first electrode layer corresponding to the electrode portion and the connecting portion of the first unit element and corresponding to the connecting portion of the second unit element; And a second electrode layer forming step of forming a second electrode layer corresponding to the electrode portion and the connection portion of the first unit element and the second unit element. The method of claim 6, In the first electrode layer forming step, an electrode layer corresponding to the connecting portion of the third unit element different from the first unit element and the second unit element is formed by the first electrode layer, In the second electrode layer forming step, an electrode layer corresponding to the connecting portion of the third unit element is formed by the second electrode layer, After the second electrode layer forming step, a third electrode layer forming step of forming a third electrode layer corresponding to the electrode portion and the connecting portion of the first unit element, the second unit element, and the third unit element. The manufacturing method of the light emitting device characterized by the above-mentioned. The method according to claim 6 or 7, In the first electrode layer forming step, the first electrode layer is formed so as to cover the stepped portion on the to-be-formed surface for forming the first electrode layer. The method of claim 8, A second electrode layer is formed on the first electrode layer so as to cover a portion corresponding to the stepped portion. The method of claim 6, And a step of forming the light reflection layer before the electrode forming step, and a step of forming a protective film covering the light reflection layer and forming a protective film having light transparency. An electronic device comprising the light emitting device according to claim 1.

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