JP2007123065A - Method of manufacturing light emitting device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a light emitting device capable of suppressing color shift depending on viewing angles, and to provide electronic equipment provided with the light emitting device manufactured by the method. <P>SOLUTION: An organic EL device 10 comprises an optical resonator structure for a blue pixel DB, green pixel DG, and red pixel DR. The pixel electrode 15B of the blue pixel DB comprises a first pixel electrode and a second pixel electrode whose film thickness is different from that of the first pixel electrode. The pixel electrodes 15B, 15G, and 15R with different film thickness are formed in each of blue, green, and red pixel electrode formation regions SB, SG, and SR in four photolithography processes. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting device and an electronic apparatus.

  2. Description of the Related Art In recent years, development of an organic electroluminescence light emitting device having a pixel including an organic electroluminescence (hereinafter referred to as “organic EL”) element using a light emitting organic material for a light emitting layer has been advanced. In general, an organic EL element has a configuration in which a functional layer including at least a light emitting layer is sandwiched between two electrodes, and light emitted from the light emitting layer is directly used as display light.

However, since the light extracted from the organic EL element as it is has a broad spectrum and low emission luminance, there is a problem that sufficient color reproducibility cannot be obtained when applied to a light emitting device. Therefore, each pixel is provided with a dielectric mirror layer (semi-transparent reflective layer), and the light emitted from the light emitting layer is reflected back and forth between one electrode and the dielectric mirror layer, so that the optical There has been proposed a light-emitting device having a resonator structure in which only light having a resonance wavelength corresponding to the distance is amplified and extracted to the outside. A light-emitting device having such a resonator structure can take out light of wavelengths corresponding to red (R), green (G), and blue (B) by appropriately changing the optical distance. (For example, refer to Patent Document 1).
Japanese Patent No. 2797883

  By the way, in the light emitting device, each electrode and the dielectric mirror are sequentially stacked in the vertical direction with respect to the substrate. Therefore, the optical distance of each pixel is vertical and oblique with respect to the substrate. Apparent optical distance is different.

  As shown in FIGS. 10 (a) and 10 (b), the light having each wavelength corresponding to blue (B) and red (R) emitted obliquely with respect to the substrate has an emission angle Q of 0. It can be seen that the peak wavelength gradually shifts to the short wavelength side as the angle becomes as wide as °, 20 °,. For example, in the light of the wavelength corresponding to blue (B) and red (R), the emission angle Q is 0 °, that is, the light emitted to the front (0 °) with respect to the substrate, and 30 with respect to the substrate. Light with a wavelength shifted by about 10 nm is emitted with light emitted with a shift of °, and light with a wavelength shifted by about 50 nm with light emitted with a shift of 60 ° with respect to the substrate.

  Therefore, the light emitted in the direction perpendicular to the substrate and the light emitted in the oblique direction are different in wavelength, so that a so-called chromaticity shift that looks different depending on the viewing angle (viewing angle) occurs. The problem will arise.

  The present invention has been made in view of such circumstances, and a method for manufacturing a light emitting device capable of suppressing a chromaticity shift depending on a viewing angle, and an electronic apparatus including the light emitting device manufactured by the manufacturing method. The purpose is to provide.

In the method for manufacturing a light emitting device according to the present invention, a light reflecting layer, a pixel electrode, a functional layer including at least a light emitting layer, and a semi-transmissive reflective layer are laminated on a substrate. The functional layer is sandwiched between and a pixel having an optical resonator structure that resonates light emitted from the light emitting layer between the light reflecting layer and the transflective layer, The optical distance between the light reflection layer and the transflective layer is composed of three kinds of first pixels, second pixels, and third pixels, and the pixel electrodes of the first pixels are: A method of manufacturing a light emitting device that includes a first region and a second region having different film thicknesses and emits light having different resonance wavelengths from the respective regions, wherein at least one of the second pixel and the third pixel When forming the pixel electrode of a pixel, the first pixel At the same time to form the pixel electrode of the at least one area of the region and the second region.

  According to this, the pixel electrode in the first or second region of the first pixel is formed at the same time when the pixel electrode of the second or third pixel is formed. Therefore, the number of steps can be reduced as compared with the case where each pixel electrode is formed for each pixel.

  In this method of manufacturing a light emitting device, among the pixel electrodes of the first pixel, the thickness of the pixel electrode in the first region is d1a, and the thickness of the pixel electrode in the second region is d1b (d1a <d1b). Furthermore, when the film thickness of the pixel electrode of the second pixel is represented by d2, and the film thickness of the pixel electrode of the third pixel is represented by d3, a third pixel electrode on which the pixel electrode of the third pixel is formed. A first step of forming a first electrode layer having a film thickness of d3-d2 in the formation region; and a film thickness of d2-d1b on the first electrode layer formed in the third pixel electrode formation region. Forming a second electrode layer, and forming a second electrode layer in a second pixel electrode formation region in which a pixel electrode of the second pixel is formed; the third pixel electrode formation region; and The second power formed in the second pixel electrode formation region, respectively. A third step of forming a third electrode layer having a thickness of d1b-d1a on the layer, and forming the third electrode layer in the first region of the first pixel; A fourth electrode layer having a thickness of d1a is formed on each of the third electrode layers formed in the pixel electrode formation region and the second pixel electrode formation region, respectively, and in the first pixel electrode formation region, A fourth step of forming the fourth electrode layer in the first region and the second region may be provided.

  According to this, pixel electrodes having different film thicknesses are formed in each region in four steps. Therefore, an optical distance optimal for optical resonance can be formed in each of the first, second, and third pixels. The pixel electrode of the third pixel is thicker than the pixel electrodes of the first and second pixels, but the pixel electrode of the third pixel is divided so as to be formed in four steps. Therefore, the etching time for forming each electrode film can be set to approximately the same time. Accordingly, when the film thickness is increased, the etching time becomes longer, so that side etching is likely to occur, but this can be suppressed.

  In this method of manufacturing a light emitting device, the first pixel is a blue pixel that emits blue light, the second pixel is a green pixel that emits green light, and the third pixel is Red pixels that emit red light may also be used.

  According to this, the pixel electrode of the blue pixel can be formed as a pixel electrode having regions having different film thicknesses. Therefore, two or more different resonance conditions are provided from the blue pixel, and light having a resonance wavelength that matches each resonance condition is emitted. As a result, the light emitted in the direction perpendicular to the substrate and the light emitted in the oblique direction have the same wavelength, so that the chromaticity deviation is suppressed depending on the viewing angle (viewing angle). Can be manufactured.

  In this method of manufacturing a light emitting device, a red conversion layer is provided at a position opposite to the red pixel, a green conversion layer is provided at a position opposite to the green pixel, and a blue conversion layer is provided at a position opposite to the blue pixel. You may have further provided the color filter.

According to this, since the color filter is provided, the viewing angle characteristics of the green pixel and the red pixel are corrected by the color filter, and the blue pixel can suppress the chromaticity shift due to the viewing angle by two resonance conditions. . As a result, a light emitting device with better color reproducibility can be manufactured.

In this method for manufacturing a light emitting device, a protective layer that covers the entire reflective layer may be formed between the light reflective layer and the pixel electrode.
According to this, the light reflection layer is generally formed of aluminum (Al) or silver (Ag). Therefore, although the light reflection layer is deteriorated by a known developer or stripping solvent used when forming the pixel electrode, a protective layer is formed on the light reflection layer as in the present invention. Therefore, it does not deteriorate. As a result, since the pixel electrode has a high light reflectance, a light-emitting device with high light extraction efficiency, that is, high luminance can be manufactured.

In this method for manufacturing a light emitting device, the protective layer may have a refractive index lower than that of the pixel electrode.
According to this, the optical resonance wavelength of each pixel is the optical distance between the light reflecting layer and the semi-transmissive reflecting layer, that is, the pixel electrode disposed between the light reflecting layer and the semi-transmissive reflecting layer, the function It is known that the optical distance of each layer corresponds to the sum of the optical distances of the layer and the protective layer, and the optical distance of each layer is obtained by the product of the film thickness and the refractive index. In the present invention, since the refractive index of the protective layer is lower than that of the pixel electrode, the optical resonance wavelength is not affected by the protective layer. When the refractive index of the protective layer is large, it is necessary to form the pixel electrode very thin from the viewpoint of the optical resonator. However, since this can be suppressed, the thickness of the pixel electrode is easy to manufacture. Can be formed.

An electronic apparatus according to the present invention includes a light emitting device manufactured by the method for manufacturing a light emitting device described above.
According to this, it is possible to provide an electronic device capable of displaying an image with suppressed chromaticity deviation even with a wide viewing angle.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing a schematic configuration of an organic EL device as a light emitting device of the present invention.

The organic EL device 10 of the present embodiment is a so-called top emission type organic EL device that extracts light (display light) emitted from the light emitting layer (internal light emission) from the side opposite to the substrate.
As shown in FIG. 1, the organic EL device 10 includes a light-transmitting substrate (transparent substrate) 11, and on the substrate 11, a blue pixel forming region ZB, a green pixel forming region ZG, and a red The pixel formation regions ZR are arranged in a matrix. Each of the blue, green, and red pixel formation regions ZB, ZG, and ZR is in the order of the blue pixel formation region ZB → the green pixel formation region ZG → the red pixel formation region ZR →. The pixel formation regions ZB, ZG, and ZR of the same color are arranged along the Z arrow direction (the rear side direction on the paper surface). A blue pixel electrode formation region SB is formed in the blue pixel formation region ZB. A green pixel electrode formation region SG as a second pixel electrode formation region is formed in the green pixel formation region ZG. A red pixel electrode formation region SR as a third pixel electrode formation region is formed in the red pixel formation region ZR.

  On the substrate 11, a plurality of light reflecting layers 12 made of a material having high light reflectivity and the like are extended in stripes along the same color pixel formation regions ZB, ZG, ZR. The light reflecting layer 12 of this embodiment is made of aluminum (Al).

A protective layer 13 is formed on each light reflecting layer 12 so as to cover the light reflecting layer 12. The protective layer 13 is made of a material having excellent light transmittance and electrical insulation. In the present embodiment, the protective layer 13 includes blue, green, and red pixel electrodes 15B and 15G described later.
, 15R is made of a material having a lower refractive index. The protective layer 13 of this embodiment is made of silicon nitride (SiN) (refractive index 1.8).

  On the protective layer 13 in each of the blue, green, and red pixel electrode formation regions SB, SG, SR, blue, green, and red pixel electrodes that are made of a light-transmitting conductive material 15B, 15G, and 15R are partitioned. That is, the plurality of blue, green, and red pixel electrodes 15B, 15G, and 15R are arranged in a matrix so as to face each light reflection layer 12 with the protective layer 13 interposed therebetween. The pixel electrodes 15B, 15G, and 15R of this embodiment are made of indium-tin oxide (ITO).

  As shown in FIG. 2, the blue pixel electrode formation region SB includes the first blue pixel electrode formation region SB1 as the first region formed on the left side (anti-X arrow direction side) in FIG. 2 and the right side in FIG. 2. And a second blue pixel electrode forming region SB2 as a second region formed on the (X arrow direction side). Hereinafter, for convenience of description, the blue pixel electrode 15B disposed on the first blue pixel electrode formation region SB1 is referred to as a first blue pixel electrode portion 18B, and is disposed on the second blue pixel electrode formation region SB2. The blue pixel electrode 15B is referred to as a second blue pixel electrode portion 19B. The film thickness d1a of the first blue pixel electrode portion 18B is thinner than the film thickness d1b of the second blue pixel electrode portion 19B. That is, the blue pixel electrode 15B has a stepped shape. In the present embodiment, the film thickness d1a of the first blue pixel electrode portion 18B is 20 nm, and the film thickness d1b of the second blue pixel electrode portion 19B is 45 nm.

  As shown in FIG. 3, in the present embodiment, the green pixel electrode 15G has a film thickness d2 of 65 nm. Further, as shown in FIG. 4, in the present embodiment, the red pixel electrode 15R has a film thickness d3 of 95 nm.

  Further, as shown in FIG. 1, a functional layer 20 is formed on the substrate 11 so as to cover the blue, green, and red pixel electrodes 15B, 15G, and 15R. In the functional layer 20 of this embodiment, a hole transport layer 21, a light emitting layer 22, and an electron transport layer 23 are sequentially stacked from the substrate 11 side. A common electrode 25 is formed on the entire surface of the functional layer 20 (on the electron transport layer 23).

  The hole transport layer 21 has a function of increasing charge injection efficiency from the blue, green, and red pixel electrodes 15B, 15G, and 15R to the light emitting layer 22, and blocking electrons moving in the light emitting layer 22. There exists an effect | action which raises the recombination probability of the electron and hole in the light emitting layer 22. FIG. For the hole transport layer 21, a material having a low injection barrier from the blue, green, and red pixel electrodes 15B, 15G, and 15R and a high hole mobility is preferably used. As such a material, for example, a polythiophene derivative, a polypyrrole derivative, or a doped body thereof is used. Specifically, a dispersion of 3,4-polyethylenedioxyophene / polystyrene sulfonic acid (PEDOT / PSS) [trade name; Bytron-p: manufactured by Bayer], that is, polystyrene sulfone as a dispersion medium. A dispersion obtained by dispersing 3,4-polyethylenedioxythiophene in an acid and further dispersing it in water can be used. In the present embodiment, the hole transport layer 21 has a uniform film thickness for each of the blue, green, and red pixel electrodes 15B, 15G, and 15R.

The light emitting layer 22 is made of a known organic polymer light emitting material capable of emitting fluorescence or phosphorescence. Such materials include polyfluorene derivatives (PF), polyparaphenylene vinylene derivatives (PPV), polyphenylene derivatives (PP), polyparaphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polydialkylfluorenes ( PDAF), polyfluorene benzothiadiazole (PFBT), polyalkylthiolene (PAT), polysilanes such as polymethylphenylsilane (PMPS), and the like can be suitably used. In addition, for each of these light emitting materials, polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, quinacridone, etc. It is also possible to use a low molecular weight material doped. In addition, in the light emitting layer 22 of this embodiment, it is comprised with the well-known polymer light emitting material which light-emits white light. In the present embodiment, the light emitting layer 22 has a uniform film thickness over the entire surface of the hole transport layer 21.

  The electron transport layer 23 enhances the electron injection efficiency from the common electrode 25 to the light emitting layer 22 and has a hole blocking function. The electron transport layer 23 is made of an organic material such as an oxadiazole derivative or Alq3. In the present embodiment, the electron transport layer 23 has a uniform film thickness over the entire surface of the light emitting layer 22.

  The common electrode 25 is an electrode that functions as a transflective layer that transmits part of the light emitted from the light emitting layer 22 and reflects part or all of the remaining light to the light reflecting layer 12 side. Therefore, the functional layer 20 is sandwiched between the common electrode 25 and the blue, green, and red pixel electrodes 15B, 15G, and 15R. An optical resonator structure that reflects and resonates light emitted from the light emitting layer 22 so as to reciprocate between the light reflecting layer 12 and the common electrode 25 disposed immediately below the pixel electrodes 15B, 15G, and 15R. Is formed.

  The blue pixel formation area ZB has a blue pixel DB as a first pixel, the green pixel formation area ZG has a green pixel DG as a second pixel, and the red pixel formation area ZR has a green pixel DG. A red pixel DR as the third pixel is assigned. Among the pixels DB, DG, and DR, the same color pixels DB, DG, and DR are arranged on the same light reflection layer 12. That is, among the pixels DB, DG, DR, the blue pixel DB includes the blue pixel electrode 15B (18B, 19B), the common electrode 25, and the blue pixel electrode 15B (18B, 19B) and the common electrode. The organic EL element 28B for blue comprised by the functional layer 20 clamped by 25 is provided. Further, the green pixel DG includes a green organic EL element 28G configured by the green pixel electrodes 15G, the common electrode 25, and the functional layer 20 sandwiched between the green pixel electrodes 15G and the common electrode 25. Is provided. Similarly, the red pixel DR includes the red pixel electrode 15R, the common electrode 25, and the red organic EL element configured by the functional layer 20 sandwiched between the red pixel electrode 15R and the common electrode 25. 28R is provided.

  Note that the pixels DB, DG, and DR in the present embodiment are composed of the light reflection layer 12, the pixel electrode 15, the functional layer 20, and the common electrode 25 formed on the substrate 11, and are formed. Indicates the region that was created. In addition, a plurality of data lines and a plurality of scanning lines (not shown) are formed on the substrate 11, and the pixels DB, DG, and DR are formed at positions corresponding to the intersections between the data lines and the scanning lines. Further, on the substrate 11 corresponding to each pixel DB, DG, DR, driving TFTs such as switching transistors and driving transistors (not shown) for controlling the light emission of the organic EL elements 28B, 28G, 28R are formed.

Next, the details of each blue pixel DB, green pixel DG, and red pixel DR configured as described above will be described.
Hereinafter, for convenience of explanation, as shown in FIG. 2, the distance between the light reflection layer 12 and the common electrode 25 in the first blue pixel electrode formation region SB1 in the blue pixel DB (this is referred to as “first distance”). LB1 and LB2 the distance between the light reflecting layer 12 and the common electrode 25 in the second blue pixel electrode formation region SB2 (referred to as “second distance”). Similarly, as shown in FIG. 3, the distance between the light reflection layer 12 and the common electrode 25 in the green pixel electrode formation region SG in the green pixel DG is set to LG. Similarly, as shown in FIG. 4, the distance between the light reflection layer 12 and the common electrode 25 in the red pixel electrode formation region SR in the red pixel DR is LR.

First, for the blue pixel DB, as shown in FIG. 2, each hole transport layer 21, light-emitting layer 22, and electron transport layer 23 have a uniform film thickness with respect to the pixel electrode 15B, so the first distance LB1. Is longer than the second distance LB2 by a difference (= d1b−d1a) between the film thickness d1a of the first blue pixel electrode portion 18B and the film thickness d1b of the second blue pixel electrode portion 19B.

  By the way, the light emitted from each pixel DB, DG, DR becomes light having a resonance wavelength according to the resonance condition of the optical resonator structure formed in each pixel DB, DG, DR. This resonance wavelength corresponds to the optical distance between the light reflecting layer 12 and the common electrode 25, that is, the sum of the optical distances of the layers disposed between the light reflecting layer 12 and the common electrode 25. The optical distance of each layer is determined by the product of its film thickness and refractive index. In the present embodiment, since the organic EL elements 28B, 28G, and 28R are all made of a common material, the refractive indexes of the respective layers are equal. Therefore, the optical distance of each pixel DB, DG, DR is determined by each distance LB1, LB2, LG, LR which is the sum of the film thicknesses of each layer. The resonance wavelength becomes longer as the optical distance becomes longer (in the present embodiment, as the distances LB1, LB2, LG, and LR become longer).

  Accordingly, the blue pixel DB includes a first optical distance corresponding to the first distance LB1 and a second optical distance corresponding to the second distance LB2. In other words, the blue pixel DB has two different resonance conditions. The green and red pixels DG and DR have optical distances corresponding to the distances LG and LR, respectively. That is, each of the green and red pixels DG and DR has one resonance condition.

  The first and second blue pixel electrode portions 18B are provided so that the first and second distances LB1 and LB2 of the blue pixel DB are both obtained by resonance of light having a wavelength corresponding to blue light. 19B, film thicknesses d1a and d2a are set. The first distance LB1 is set so that the resonance wavelength PB1 of the blue light HB1 emitted along the direction perpendicular to the substrate 11 (the direction indicated by the arrow Y in FIG. 2) becomes a predetermined desired blue light. The film thickness d1a of the 1-blue pixel electrode portion 18B is adjusted in advance (20 nm in this embodiment). In addition, since the second distance LB2 is longer than the first distance LB1, the optical distance is increased accordingly, so that the blue light HB2 having a longer wavelength than the resonance wavelength PB1 is emitted. In the present embodiment, the second distance LB2 is set in advance so that the film thickness d1b of the second blue pixel electrode portion 19B is set so that the resonance wavelength PB2 of the light HB2 satisfies the following equation (1) (this embodiment: In the case of 45 nm).

(PB1 + 10 nm) ≦ PB2 ≦ (PB1 + 50 nm) (1)
The resonance wavelength PB2 of the light HB2 satisfying the above equation (1) is the resonance of the light emitted in the direction perpendicular to the substrate 11 when the emission angle is emitted in an oblique direction with respect to the substrate 11 at 60 °. The wavelength is substantially equal to the wavelength PB1. That is, the wavelength of blue light emitted from the blue pixel DB in the vertical direction is substantially equal to the wavelength of blue light emitted in the oblique direction. Here, the emission angle means an angle formed by a parallel direction (X arrow direction in FIG. 2) with respect to a direction perpendicular to the substrate 11 (Y arrow direction in FIG. 2). For example, the exit angle in the direction perpendicular to the substrate 11 is 0 °, and the exit angle in the direction parallel to the substrate 11 from the perpendicular direction is 90 °.

  The distance LB of the green pixel DG is set to a film thickness d2 (65 nm) so that light having a wavelength corresponding to green light can be obtained by resonance. The distance LR of the red pixel DR is set to a film thickness d3 (95 nm) so that light having a wavelength corresponding to red light can be obtained by resonance.

As shown in FIG. 1, a color filter 51 is attached on the common electrode 25. The color filter 51 includes a light transmissive color filter substrate 52. The color filter substrate 52 transmits blue, green, and red light having wavelengths corresponding to the resonance wavelengths of the pixels DB, DG, and DR. Conversion layers 53B, 53G, and 53R are provided. Each color conversion layer 53B, 53G, 53R is partitioned and arranged in a matrix by a black matrix BM.

  In the color filter 51, the blue conversion layer 53B is opposed to the blue pixel DB, the green conversion layer 53G is opposed to the green pixel DG, and the red conversion layer 53R is relative to the red pixel DR. It is attached on the common electrode 25 so as to be arranged at the facing position.

  FIG. 5 is a graph showing the light transmittance with respect to the wavelength of each of the blue, green, and red conversion layers 53B, 53G, and 53R. In FIG. 5, a curve 55B is a curve showing the light transmittance of the blue conversion layer 53B, a curve 55G is a curve showing the light transmittance of the green conversion layer 53G, and a curve 55R is a curve showing the light transmittance of the red conversion layer 53R. . In FIG. 5, curves Lb1 and Lb2 are emission spectra of the light HB1 having the resonance wavelength PB1 and the light HB2 having the resonance wavelength PB2, respectively. Similarly, the curve Lg is the emission spectrum of the light HG having the resonance wavelength PG, and the curve Lr is the emission spectrum of the light HR having the resonance wavelength PR.

  As shown in FIG. 5, in this embodiment, the resonance wavelengths PB2, PG, PR of the light HB2, HG, HR emitted from each blue pixel DB, green pixel DG, and red pixel DR are blue, The distances LB2, LR, and LB are appropriately adjusted so as to coincide with the wavelength indicating the maximum transmittance in the light transmittance characteristics of the green and red conversion layers 53B, 53G, and 53R.

Next, a method for manufacturing the organic EL device 10, in particular, a method for forming the pixel electrodes 15 </ b> B, 15 </ b> G, and 15 </ b> R that determines each optical distance will be described with reference to FIGS. 6 to 8.
As described above, the film thickness d1a of the first blue pixel electrode portion 18B is 20 nm, the film thickness d1b of the second blue pixel electrode portion 19B is 45 nm, the film thickness d2 of the green pixel electrode 15G is 65 nm, red The pixel electrode 15R is formed so that the film thickness d3 is 95 nm.

  First, a light-transmitting substrate (transparent substrate) 11 made of glass or the like is prepared, and driving TFTs such as data lines, scanning lines, switching transistors, and driving transistors (not shown) are formed on the substrate 11 by a known method. Form. Then, as shown in FIG. 6A, stripe-like light reflecting layers 12 are formed on the blue, green, and red pixel formation regions ZB, ZG, and ZR arranged in a row. In the present embodiment, the light reflecting layer 12 is formed by sputtering aluminum (Al) on the entire surface of the substrate 11 and patterning it.

  Subsequently, silicon nitride (SiN) is sputtered over the light reflection layer 12 over the entire surface of the substrate 11 and patterned to form the protective layer 13 so as to cover the light reflection layer 12. . In the present embodiment, the protective layer 13 having a thickness of 50 nm is formed.

  Next, on the red pixel electrode formation region SR, a light transmission having a difference (= d3−d2 = 30 nm) between the film thickness d3 of the red pixel electrode 15R and the film thickness d2 of the green pixel electrode 15G. A conductive film having the property is formed by photolithography. Specifically, as shown in FIG. 6B, a conductive film 61 made of indium-tin oxide (ITO) is formed on each protective layer 13 to a thickness of 30 nm by sputtering. . Thereafter, a known resist film is applied to the entire surface of the conductive film 61, and resist precure, mask exposure, and resist development are sequentially performed, so that the resist film 62 is formed only on the conductive film 61 on the red pixel electrode formation region SR. Form.

  Subsequently, the conductive film 61 is etched through the resist film 62, and the resist film 62 is peeled and removed. As a result, as shown in FIG. 6C, the conductive film 61 having a film thickness of 30 nm is patterned and formed only on the protective layer 13 on the red pixel electrode formation region SR. Hereinafter, for convenience of explanation, at this time, the conductive film 61 formed on the protective layer 13 on the red pixel electrode formation region SR is referred to as a first electrode layer Q1, and its film thickness T1 is 30 nm.

  Next, the difference (= d2) between the film thickness d2 of the green pixel electrode 15G and the film thickness d1b of the second blue pixel electrode portion 19B on the red pixel electrode formation region SR and the green pixel electrode formation region SG. A conductive film having a light transmission property with a film thickness of −d1b = 20 nm is formed by photolithography. Specifically, as shown in FIG. 6D, a conductive film 63 made of indium-tin oxide (ITO) is formed on each protective layer 13 to a thickness of 20 nm by sputtering. . Thereafter, a known resist film is applied to the entire surface of the conductive film 63, and resist precure, mask exposure, and resist development are sequentially performed. As shown in FIG. A resist film 64 is formed on the conductive film 63 on the green pixel electrode formation region SG.

  Subsequently, the conductive film 63 is etched through the resist film 64, and the resist film 64 is peeled and removed. As a result, as shown in FIG. 7B, on each protective layer 13 on the red pixel electrode formation region SR, a conductive film 63 having a thickness of 20 nm on the first electrode layer Q1 formed previously. Is formed by patterning. Further, a conductive film 63 having a thickness of 20 nm is patterned on each protective layer 13 on the green pixel electrode formation region SG. Hereinafter, for convenience of explanation, the conductive film 63 formed on each of the protective layers 13 on the red and green pixel electrode formation regions SR and SG is referred to as a second electrode layer Q2, and its film thickness T2 is 20 nm. It becomes.

  Next, the film thickness d1a of the first blue pixel electrode portion 18B and the second blue pixel electrode portion SB2 are respectively formed on the red and green pixel electrode formation regions SR, SG and the second blue pixel electrode formation region SB2. A light-transmitting conductive film having a film thickness difference (= d1b−d1a = 25 nm) from the film thickness d1b of 19B is formed by photolithography. Specifically, as shown in FIG. 7C, a conductive film 65 made of indium-tin oxide (ITO) is formed on each protective layer 13 to a thickness of 25 nm by sputtering. . Thereafter, a known resist film is applied to the entire surface of the conductive film 65, and resist precure, mask exposure, and resist development are sequentially performed, so that the red and green pixel electrode formation regions SR and SG and the second blue pixel electrode are applied. A resist film 66 is formed on the conductive film 65 on the formation region SB2.

  Subsequently, the conductive film 65 is etched through the resist film 66, and the resist film 66 is peeled and removed. As a result, as shown in FIG. 7 (d), on each of the protective layers 13 on the red and green pixel electrode formation regions SR and SG, the film thickness of 25 nm is formed on the second electrode layer Q2 formed previously. The conductive film 65 is formed by patterning. In addition, a conductive film 65 having a film thickness of 25 nm is formed by patterning on each protective layer 13 on the second blue pixel electrode formation region SB2. Hereinafter, for convenience of explanation, at this time, the conductive film 65 formed on each protective layer 13 on the red, green, and second blue pixel electrode formation regions SR, SG, SB2 is referred to as a third electrode layer Q3. The film thickness T3 is 25 nm.

  Next, light having a thickness d1a (= 20 nm) of the first blue pixel electrode portion 18B on the red and green pixel electrode formation regions SR and SG and the blue pixel electrode formation region SB, respectively. A conductive film having transparency is formed by photolithography. Specifically, as shown in FIG. 8A, a conductive film 67 made of indium-tin oxide (ITO) is formed on each protective layer 13 to a thickness of 20 nm by sputtering. . Thereafter, a known resist film is applied to the entire surface of the conductive film 67, and resist precure, mask exposure, and resist development are sequentially performed. As shown in FIG. 8B, red, green, and blue pixel electrodes are formed. A resist film 68 is formed on each conductive film 67 on the formation regions SR, SG, and SB.

Subsequently, the conductive film 67 is etched through each of the resist films 68, and the resist film 68 is further removed. As a result, as shown in FIG. 8C, the first and second pixel layers formed on the protective layers 13 on the red and green pixel electrode formation regions SR and SG and the second blue pixel electrode formation region SB2 are formed. A conductive film 67 having a thickness of 20 nm is formed by patterning on the three-electrode layer Q3, and a conductive film 67 having a thickness of 20 nm is formed by patterning on each protective layer 13 on the first blue pixel electrode formation region SB1. The Hereinafter, for convenience of explanation, the conductive film 67 formed on each protective layer 13 on the red, green, and second blue pixel electrode formation regions SR, SG, and SB2 is referred to as a fourth electrode layer Q4.

  As described above, the first to fourth electrode layers Q1, Q2, Q3, and Q4 are laminated on the protective layer 13 in the red pixel electrode formation region SR, and the red pixel electrode 15R having a film thickness d3 (= T1 + T2 + T3 + T4 = 95 nm). Is formed. Further, the second to fourth electrode layers Q2, Q3, and Q4 are laminated on the protective layer 13 in the green pixel electrode formation region SG to form a green pixel electrode 15G having a film thickness d2 (= T2 + T3 + T4 = 65 nm). The Further, a fourth electrode layer Q4 is laminated on the protective layer 13 in the first blue pixel electrode formation region SB1 to form a first blue pixel electrode portion 18B having a film thickness d1a (= T4 = 20 nm). The third and fourth electrode layers Q3 and Q4 are stacked on the protective layer 13 in the second blue pixel electrode formation region SB2, and the second blue pixel electrode portion 19B having a film thickness d1b (= T3 + T4 = 45 nm) is formed. It is formed.

  Subsequently, the hole transport layer 21, the light emitting layer 22, and the electron transport layer 23 are sequentially formed on the entire surface of the substrate 11 over the pixel electrodes 15B, 15G, and 15R. Each of these layers 21, 22, and 23 is formed by a vapor deposition method. The functional layer 20 is formed by the hole transport layer 21, the light emitting layer 22, and the electron transport layer 23. In the present embodiment, the light emitting layer 22 is formed of a light emitting organic material.

  Thereafter, the common electrode 25 is formed on the functional layer 20. In the present embodiment, the common electrode 25 is formed by sputtering. As the common electrode 25, a light-transmitting conductive material such as indium-tin oxide (ITO) is used. Such a conductive material functions as a transflective film and forms an optical resonator structure that resonates light emitted from the light emitting layer 22 between the pixel electrodes 15B, 15G, and 15R. Thereafter, a driving driver or the like (not shown) is mounted on the substrate 11, and a color filter 50 separately manufactured by a known method is bonded onto the common electrode 25, whereby the organic EL device 10 is completed.

As described above, the present embodiment has the following effects.
(1) According to the present embodiment, the blue pixel DB has two resonance conditions. Accordingly, each blue pixel DB emits blue light HB1 having a resonance wavelength PB1 and blue light HB2 having a resonance wavelength PB2 that is longer than the resonance wavelength PB1. As a result, the light emitted in the oblique direction with respect to the substrate 11 has a shorter wavelength than the light emitted in the direction perpendicular to the substrate 11, but each resonance wavelength PB2 is a long wavelength in advance. The light emitted in an oblique direction with respect to the substrate 11 becomes substantially equal in wavelength to light emitted in the direction perpendicular to the substrate 11. Therefore, it is possible to display an image that does not cause a so-called chromaticity shift, which looks different in color depending on the viewing angle (viewing angle) with respect to the substrate 11.

  (2) According to the present embodiment, the pixel electrodes 15B, 15R, and 15R having different film thicknesses are formed for the blue, green, and red pixel electrode formation regions SB, SG, and SR in four photolithography processes. Can do. Therefore, an optical distance optimal for optical resonance can be formed in each of the first, second, and third pixels.

  (3) According to the present embodiment, the red pixel electrode 15R is thicker than the other green pixel electrode 15G and the blue pixel electrode 15B. Since it is divided so as to be formed by a photolithography process, the etching time for forming the pixel electrodes 15B, 15G, and 15R can be set to approximately the same time. As a result, when the film thickness is increased, the etching time becomes longer and side etching is likely to occur, but this can be suppressed.

  (4) According to the present embodiment, among the light emitted from each of the pixels DB, DG, and DR having the optical resonance structure, only the light that has passed through the color filter 51 is extracted to the outside. A good organic EL device can be realized.

  (5) According to the present embodiment, the blue, green, and red conversion layers 53B, 53G, and 53R of the color filter 51 have the resonance wavelengths PB1, PG, and PR of the lights HB1, HG, and HR, respectively, blue, green, and It matches the wavelength indicating the maximum transmittance in each light transmittance characteristic of the red color conversion layers 53B, 53G, and 53R. Therefore, it is possible to realize an organic EL device in which color deviation of red, green, and blue light is suppressed without reducing luminance.

  (6) According to the present embodiment, the protective layer 13 is formed between the light reflecting layer 12 and the pixel electrodes 15B, 15G, and 15R so as to cover the entire light reflecting layer 12. Accordingly, since the known developer and the solvent of the stripping solution used when forming the pixel electrodes 15B, 15G, and 15R do not come into direct contact with the light reflecting layer 12, the light reflecting layer 12 is not the developer or the stripping solution. There is no deterioration by the solvent. As a result, each of the pixel electrodes 15B, 15G, and 15R has a high light reflectance, so that an organic EL device with high light extraction efficiency, that is, high luminance can be realized.

  (7) According to the present embodiment, the protective layer 13 is made of a material having a lower refractive index than the pixel electrodes 15B, 15G, and 15R. Therefore, the resonance wavelengths PB1, PG, and PR of the light beams HB1, HG, and HR are not affected by the protective layer 13. Therefore, when the refractive index of the protective layer 13 is large, the pixel electrodes 15B, 15G, and 15R need to be formed very thin from the viewpoint of the optical resonator, but this can be suppressed. As a result, the pixel electrodes 15B, 15G, and 15R can be formed with thicknesses that are easy to manufacture.

  (8) According to this embodiment, each layer of the protective layer 13 and the functional layer 20 has a uniform film thickness for each pixel DB, DG, DR. Therefore, since the film thickness of the light emitting layer 22 is not changed, two or more different resonance conditions can be provided for each blue pixel DB without changing the light emission characteristics of each pixel DB, DG, DR.

(9) According to the present embodiment, the resonance wavelength PB2 of the light HB2 emitted from each blue pixel DB is determined so as to satisfy the above equation (1). Therefore, the wavelength of the light emitted from each blue pixel DB at an emission angle of 60 ° with respect to the substrate 11 can be made substantially equal to the resonance wavelength PB1 of the light emitted in the direction perpendicular to the substrate 11. . As a result, the color shift of blue light is suppressed even when the viewing angle is about 60 °. Accordingly, it is possible to realize the organic EL device 10 that can emit blue light with no chromaticity deviation even with a wide viewing angle.
(Second Embodiment)
Next, an example of an electronic apparatus including the organic EL device 10 according to the first embodiment will be described.

  FIG. 9 is a perspective view showing an example of a mobile phone. A cellular phone 80 shown in FIG. 9 includes a plurality of operation buttons 81, a mouthpiece 82, a mouthpiece 83, and a display unit 84. The mobile phone 80 configured as described above includes the display unit 84 including any one of the organic EL devices 10, 50, 60, and 70 according to the first to fourth embodiments. Therefore, an image with suppressed chromaticity deviation is displayed on the display unit 84 of the mobile phone 80 even when the viewing angle is wide.

In addition, this invention can also be changed and embodied as follows.
In each of the above embodiments, the blue pixel DB has two resonance conditions, and light of two types of resonance wavelengths corresponding to the resonance conditions is emitted, but the present invention is not limited to this. In short, light of two types of resonance wavelengths may be emitted from any one of the blue pixel DB, the green pixel DG, and the red pixel DR.

  In the first embodiment, the light emitting layer 22 is applied to the organic EL device 10 using a light emitting organic material. However, the light emitting element includes a material other than the light emitting organic material (for example, a light emitting diode (LED)). The present invention can also be applied to a light emitting device using an element.

  In the second embodiment, the mobile phone 80 has been described as an electronic device. However, the present invention is not limited to this, and can be widely applied to electronic devices having a display such as a mobile personal computer and a digital camera. .

  In each of the above embodiments, the functional layer 20 is configured by the hole transport layer 21, the light emitting layer 22, and the electron transport layer 23, but the present invention is not limited to this. Any one or all of the above layers 21 to 23 other than the light emitting layer 22 (a hole injection layer or an electron injection layer) may be included. In short, the functional layer 20 only needs to include the light emitting layer 22. By doing in this way, the same effect as each above-mentioned embodiment can be acquired.

  In the first embodiment, the substrate 11 is a light-transmitting substrate (transparent substrate) such as glass, but the present invention is not limited to this. For example, a substrate that does not transmit light (an opaque substrate) can also be used. When the substrate 11 is a substrate that does not transmit light (opaque substrate), for example, a ceramic sheet such as alumina, a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation, or thermosetting Examples thereof include a resin, a thermoplastic resin, and a film (plastic film). In short, any pixel can be used as long as the pixel can be formed.

  -In the said 1st Embodiment, although the light reflection layer 12 was comprised with aluminum (Al), it is not limited to this, As long as it is excellent in light reflectivity, it may be comprised with what kind of material. . For example, you may be comprised with silver (Ag).

  In the first embodiment, the unit pixel is embodied as the blue, green, and red pixels DB, DG, and DR. However, the unit pixel is embodied as a pixel other than the blue, green, and red pixels DB, DG, and DR. May be. For example, the present invention may be embodied in pixels of colors that emit light of colors other than blue, green, and red.

  In the first embodiment, the light emitting layer 22 is embodied in the so-called top emission type organic EL device 10 that takes out light emitted from the side opposite to the substrate 11, but the present invention is not limited to this. The so-called bottom emission type organic EL device 10 that extracts light emitted from the light emitting layer 22 from the substrate 11 side can also be applied to the manufacturing method of the pixel electrodes 15B, 15G, and 15R.

  In the first embodiment, the protective layer 13 is made of silicon nitride (SiN), but the present invention is not limited to this. It may be made of silicon oxynitride (SiON), silicon oxide (SiOn), or acrylic resin. In short, any material that has optical transparency and a higher refractive index than the pixel electrodes 15B, 15G, and 15B may be used.

1 is a cross-sectional view of an organic EL device according to a first embodiment. The expanded sectional view of the pixel for blue. The expanded sectional view of the pixel for green. The expanded sectional view of the pixel for red. The graph which shows the light transmittance of a color filter. (A), (b), (c), (d) is a figure for demonstrating the manufacturing method of an organic electroluminescent apparatus, respectively. Similarly, (a), (b), (c), and (d) are diagrams for explaining a method of manufacturing an organic EL device, respectively. Similarly, (a), (b), and (c) are diagrams for explaining a method of manufacturing an organic EL device, respectively. The perspective view of the mobile telephone as an electronic device. (A) is the emission intensity of blue light emitted at various emission angles, and (b) is the emission intensity of red light emitted at various emission angles.

Explanation of symbols

  DB ... Blue pixel as the first pixel, DG ... Green pixel as the second pixel, DR ... Red pixel as the third pixel, Q1 ... First electrode layer, Q2 ... Second electrode layer, Q3 ... First Three electrode layers, Q4 ... fourth electrode layer, SG ... green pixel electrode formation region as second pixel electrode formation region, SR ... red pixel electrode formation region as third pixel electrode formation region, 10 ... as light emitting device Organic EL device, 11 ... substrate, 12 ... light reflecting layer, 15B ... blue pixel electrode as pixel electrode, 15G ... green pixel electrode as pixel electrode, 15R ... red pixel electrode as pixel electrode, 20 ... Functional layer, 21 ... hole transport layer, 22 ... light emitting layer, 23 ... electron transport layer, 25 ... common electrode as second electrode, 51 ... color filter, 53B ... blue conversion layer, 53G ... green conversion layer, 53R ... Red color conversion layer, 80 ... Portable power as electronic equipment .

Claims (7)

On the substrate, a light reflecting layer, a pixel electrode, a functional layer including at least a light emitting layer, and a semi-transmissive reflective layer are laminated, and the functional layer is sandwiched between the light reflective layer and the semi-transmissive reflective layer, Comprising a pixel having an optical resonator structure for resonating light emitted from the light emitting layer between the light reflecting layer and the transflective layer;
The pixel is composed of three types of first pixel, second pixel, and third pixel having different optical distances between the light reflecting layer and the semi-transmissive reflecting layer,
The pixel electrode of the first pixel includes a first region and a second region having different thicknesses, and a method for manufacturing a light emitting device that emits light having a different resonance wavelength from each region,
When forming the pixel electrode of at least one of the second pixel and the third pixel, the pixel electrode of at least one of the first region and the second region of the first pixel is simultaneously formed. A method for manufacturing a light-emitting device. In the manufacturing method of the light-emitting device according to claim 1,
Of the pixel electrodes of the first pixel, the thickness of the pixel electrode in the first region is d1a, the thickness of the pixel electrode in the second region is d1b (d1a <d1b), and When the film thickness of the pixel electrode is represented by d2, and the film thickness of the pixel electrode of the third pixel is represented by d3,
A first step of forming a first electrode layer having a thickness of d3-d2 in a third pixel electrode formation region in which a pixel electrode of the third pixel is formed;
A second pixel electrode on which a second electrode layer having a thickness of d2-d1b is formed on the first electrode layer formed in the third pixel electrode formation region, and a pixel electrode of the second pixel is formed; A second step of forming the second electrode layer in a formation region;
A third electrode layer having a thickness of d1b-d1a is formed on each of the second electrode layers formed in the third pixel electrode formation region and the second pixel electrode formation region, respectively, and the first A third step of forming the third electrode layer in the first region of the pixel;
A fourth electrode layer having a thickness of d1a is formed on each of the third electrode layers formed in the third pixel electrode formation region and the second pixel electrode formation region, respectively, and the first pixel electrode And a fourth step of forming the fourth electrode layer in the first region and the second region. In the manufacturing method of the light-emitting device of Claim 1 or 2,
The first pixel is a blue pixel that emits blue light;
The second pixel is a green pixel that emits green light,
The method of manufacturing a light emitting device, wherein the third pixel is a red pixel that emits red light. In the manufacturing method of the light-emitting device according to claim 3,
The color filter further includes a red color conversion layer at a position opposite to the red pixel, a green color conversion layer at a position opposite to the green pixel, and a blue color conversion layer at a position opposite to the blue pixel. A method for manufacturing a light-emitting device. In the manufacturing method of the light-emitting device as described in any one of Claims 1-4,
A method for manufacturing a light emitting device, wherein a protective layer is formed between the light reflection layer and the pixel electrode to cover the entire reflection layer. In the manufacturing method of the light-emitting device according to claim 5,
The method for manufacturing a light emitting device, wherein the protective layer has a refractive index lower than that of the pixel electrode. An electronic apparatus comprising the light emitting device manufactured by the method for manufacturing a light emitting device according to claim 1.

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