JP2003332633A - Display device and method of manufacturing display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device that does not require pixel replacement even when defects occur in light emitting diodes used as display elements and hardly causes pixel missing and color shading in a displayed picture. <P>SOLUTION: In this display device, pixels each of which is constituted by combining sub-pixels emitting different colors of light rays with each other are arranged in a matrix-like state on a holding substrate. Each sub-pixel is constituted of a plurality of light emitting elements which emit almost the same color of light rays. In the display device, in addition, light emitting elements are formed on a plurality of semiconductor growing substrates and the plurality of light emitting elements constituting each sub-pixel is made to become light emitting elements grown by crystallinity on different semiconductor growing substrates by transferring the light emitting elements formed on the plurality of semiconductor growing substrates to each sub-pixel constituting a pixel on the holding substrate. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using a light emitting diode as a display pixel and a method for manufacturing the display device.

[0002]

2. Description of the Related Art When pixels are arranged in a matrix and assembled into an image display device, a liquid crystal display device (LC
D: Liquid Crystal Display)
And plasma display panel (PDP: Plasma)
A device is directly formed on a substrate like a display panel, or a single LED package is arranged like a light emitting diode display (LED display). For example, LCD,
In an image display device such as a PDP, since it is not possible to separate the elements, it has been usual to form the respective elements with a space corresponding to the pixel pitch of the image display device from the beginning of the manufacturing process.

On the other hand, in the case of an LED display, L
The ED chip is taken out after dicing, individually connected to an external electrode by wire bonding or bump connection by flip chip, and packaged. Since LEDs (light emitting diodes), which are light emitting elements, are expensive, it is possible to reduce the cost of an image display device using LEDs by manufacturing many LED chips from one wafer. That is, the size of the LED chip is about 3
The price of an image display device can be reduced by manufacturing an image display device by packaging an LED chip of several tens of μm square instead of a 00 μm square one.

As mentioned above, light emitting diodes (LEDs)
An image display device (LED display) using is usually constructed by regularly mounting a display panel including LEDs on a plane.
In the case of the D display, if the mounted display panel has a defect, pixel drop occurs in which the LED does not light up, and the image quality is greatly impaired. Further, if the emission wavelengths of the LEDs are different from each other or the emission brightness is varied, color unevenness occurs due to a defective coloring that cannot perform the same color display in all pixels.

Since a display using LEDs as a light emitting source has a structure in which all pixels are independently mounted, if there are pixels that do not light up or pixels that are not colored after the entire manufacturing process, It is possible in principle to repair. However, in the image display device using the LED, a physical communication path is required for transmitting and receiving signals, and wiring connection is performed by a method such as a cable, aluminum wiring, or wire bonding. Attempting to implement it involves fine and difficult work such as repairing wiring and insulating layers.

Therefore, after manufacturing the display using the LED, the number of manufacturing steps and the manufacturing cost are increased in order to remove the pixels that do not light up or the pixels with defective coloring and replace the LEDs with lights up, and then reconnect the wiring. There was a problem of doing it.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed in view of such a conventional situation, and it is not necessary to exchange pixels even when a defect occurs in a light emitting diode which is a display element, and a display is provided. It is an object of the present invention to provide a display device and a method of manufacturing the display device in which pixel defects and color unevenness are unlikely to occur.

[0008]

In the display device of the present invention for solving the above-mentioned problems, the pixels formed by combining partial pixels that emit different colors are arranged in a matrix on a holding substrate, The pixel is characterized by being composed of a plurality of light emitting elements that emit light of substantially the same color.

Since a partial pixel (sub-pixel) is formed by a plurality of light-emitting elements that emit light of substantially the same color, even when some of the light-emitting elements in the sub-pixel have defective light emission or defective color development. Since the sub-pixels themselves do not have defective light emission or defective color development, it is possible to reduce pixel defects and color unevenness without replacing the pixels of the display device.

Further, the display device of the present invention for solving the above-mentioned problems is characterized in that a plurality of light emitting elements constituting the partial pixels are light emitting elements crystal-grown on different semiconductor growth substrates. .

By forming a sub-pixel by a plurality of light emitting elements formed on different semiconductor growth substrates, even when there is a bias due to the semiconductor growth substrate in the emission wavelength and brightness characteristics of the light emitting elements, the sub pixels are Since the emission wavelength and the luminance are averaged in the pixel, it is possible to perform display with reduced color unevenness.

Further, a method of manufacturing a display device of the present invention for solving the above-mentioned problems includes a step of forming light emitting elements on a plurality of semiconductor growth substrates and a partial pixel forming a pixel on a holding substrate. A step of transferring the light emitting device from the plurality of semiconductor growth substrates.

By forming a light emitting device on a plurality of semiconductor growth substrates and transferring the light emitting devices from the plurality of semiconductor growth substrates into one subpixel, the semiconductor growth substrate can be provided with characteristics of emission wavelength and brightness of the light emitting device. Even if there is a bias due to the deviation, the emission wavelength and the luminance are averaged in the sub-pixels, and thus display with reduced color unevenness can be performed.

[0014]

DETAILED DESCRIPTION OF THE INVENTION

[First Embodiment] Hereinafter, a semiconductor package and a display device to which the present invention is applied will be described in detail with reference to the drawings. 1A and 1B are plan views showing a configuration of a semiconductor package used in a display device of the present invention, FIG. 1A is a plan view, and FIG. 1B is a front view.

An n-type layer 2 having n-type doping of a plurality of GaN-based semiconductors is formed on a base growth substrate 1 which is a sapphire substrate, and an n-electrode 3 and p-type doping are performed on the n-layer 2. A plurality of p layers 4 are formed, and a p electrode 5 is formed on each p layer 4. Here, an example in which three p layers 4 are formed in a row is shown, but the number of p layers 4 and the arrangement method are not particularly limited. Although the undergrowth substrate 1 is a sapphire substrate, any substrate that can grow a semiconductor layer may be used, and the n layer 2 and the p layer 4 formed on the undergrowth substrate 1 are also GaN-based semiconductors. Not limited to

On the surface of the underlying growth substrate 1 on which the n-electrode 3, p-layer 4 and p-electrode 5 are formed, an insulating layer 6 is laminated so as to cover these structures. A p-side hole 7 reaching the p-electrode 5 is formed in the insulating layer 6, and the p-side hole 7 is filled with a metal and electrically connected to the p-electrode 5. Further, an n-side hole 8 reaching the n-electrode 3 is formed in the insulating layer 6, and the n-side hole 8 is filled with a metal and electrically connected to the n-electrode 3. On the insulating layer 6, the p-side pad electrode 9 and n
The side pad electrode 10 is formed.

Next, a method of manufacturing the above-described semiconductor light emitting device package will be described below with reference to FIGS. 2 and 3. An n-layer 2 that is an n-type doped layer of a GaN-based semiconductor is stacked on the underlying growth substrate 1, and a p-layer 4 that is a p-type doped layer is stacked on the n layer 2 (FIG. 2a). At this time, the n-layer 2 and the p-layer 4 are formed by metalorganic vapor phase epitaxy (MOC).
VD: metal-organic chemical
vapor deposition) and hydride vapor phase epitaxy (HVPE: Hybrid Vapor)
Phase Epitaxy) and molecular beam epitaxy (MBE: Molecular Beam Epit).
Axy) or the like is used and there is no particular limitation.

After patterning on the p layer 4 using a negative photoresist, titanium / nickel (Ti / Ni) of 10/300 n is formed by using an electron beam evaporation apparatus.
m, and the resist is lifted off using acetone to form a metal mask, and the p layer 4 is etched to the n layer 2 using a dry etching apparatus.
The metal mask is removed using a mixed solution of nitric acid: hydrochloric acid = 1: 3. As a result, island-shaped regions of the p layer 4 are formed on the n layer 2 (FIG. 2b). Although the photolithography technique is illustrated here, another technique may be used as long as it is a lithography technique. Although the electron beam exposure apparatus is used for depositing the metal for the metal mask, a hot filament vapor deposition apparatus, a sputtering apparatus, or the like may be used.

Next, after patterning is performed using a negative type photoresist, Ti /
Ni was deposited to a thickness of 10/300 nm and a resist was removed to form a metal mask, and the n layer 2 was etched to the underlying growth substrate 1 using a dry etching apparatus, and then nitric acid: hydrochloric acid = 1: 3 was used. The metal mask is removed using a mixed solution. As a result, an island-shaped region of the n layer 2 is formed on the underlying growth substrate 1 (FIG. 2).
c).

Next, after patterning is performed using the photolithography technique, nickel / platinum / gold (Ni / Pt / Au) of 1 is respectively used by using an electron beam evaporation apparatus.
The p-electrode 5 is formed on the p-layer 4 by depositing 0/50/100 nm and removing the resist (FIG. 2d).

Next, after patterning is performed using the photolithography technique, titanium / platinum / gold (Ti / Pt / Au) of 10 each is formed using an electron beam vapor deposition apparatus.
/ 50/100 nm is deposited and the resist is removed to form the n-electrode 3 on the n-layer 2 (FIG. 3e). In this embodiment, Ni / Pt / Au is used as the p electrode 5, and the n electrode 3 is used.
Although the case where Ti / Pt / Au is used is shown as above, the present invention is not limited to this as long as the electrode is formed so that electrical connection with low contact resistance can be obtained.

Next, using a spin coating technique, a photosensitive polyimide is applied to the surface of the underlying growth substrate 1 where the p layer 2 and the n layer 3 are formed, and then 350 ° C. in a nitrogen atmosphere.
The insulating layer 6 is formed by baking the polyimide under the condition of 30 minutes (FIG. 3f).

Next, patterning is performed on the insulating layer 6 by using a photolithography technique to remove the exposed region of the insulating layer 6, and the n-side hole 8 reaching the n-electrode 3 and the p-electrode. A p-side hole 7 reaching 5 is formed in the insulating layer 6 (FIG. 3g).

A p-side hole 7 and an n-side hole 8 are formed on the insulating layer 6 at positions corresponding to the p-side hole 7 and the n-side hole 8 by using a sputtering apparatus.
The side hole 8 is filled with metal. Here, the kind of metal with which the p-side hole 7 and the n-side hole 8 are filled is not particularly limited, and may be a metal used for wiring such as copper or aluminum. After that, titanium / aluminum (Ti /
Al) is deposited on the insulating layer 6 at a thickness of 10/200 nm and patterned by using a photolithography technique, and Al and Ti are etched by using phosphoric acid, ammonia and hydrogen peroxide solution. p
The side pad electrode 9 and the n-side pad electrode 10 are formed (FIG. 3h).

1 to 3, the structure and the manufacturing method of one semiconductor light emitting device package are described, but a normal semiconductor package and an LED (light-e) are used.
Similar to the manufacturing of the mixing diode, a plurality of packages are collectively formed on one undergrowth substrate, and the individual packages are separated by a dicing process.

By the manufacturing method shown in FIGS. 2 and 3, a semiconductor light emitting device package 11 in which a plurality of p layers 4 are formed on the n layer 2 is obtained. By applying a voltage between the p-side pad electrode 9 and the n-side pad electrode 10,
Since a potential difference is generated between the p electrode 5 and the n electrode 3 of the layer 4, and the combination of each p layer 4 and the n layer 2 functions as a light emitting element,
The semiconductor light emitting device package emits light.

Referring to FIGS. 4 and 5, after holding the semiconductor light emitting device package on the underlying growth substrate on an adhesive sheet having an adhesive layer formed on the sheet, the semiconductor light emitting device package is selectively placed on the substrate. A method of arranging the semiconductor light emitting device packages for arranging to manufacture the display device will be described.

In this embodiment, the semiconductor light emitting device package on the underlying growth substrate is held on the adhesive sheet without being expanded, and then the semiconductor light emitting device package is selectively released from the adhesive sheet to separate the semiconductor light emitting device packages from each other. In the case of arranging the semiconductor light emitting device packages in an enlarged manner, the semiconductor light emitting device packages may be arranged on the adhesive sheet after the distance between the semiconductor light emitting device packages is expanded and held.

As shown in FIG. 4A, the undergrowth substrate 1
A semiconductor light emitting device package 11, which is a plurality of light emitting devices, is formed on the main surface of. The undergrowth substrate 1 is a semiconductor light emitting device package 11 such as a sapphire substrate.
A substrate having a high transmittance with respect to the wavelength of the laser light emitted from the back surface side when separating from the undergrowth substrate 1 is used. The plurality of semiconductor light emitting device packages 11 are separated for each semiconductor light emitting device package 11 by anisotropic etching such as reactive ion etching, and the individual semiconductor light emitting device packages 11 are in a separable state. The distance between the semiconductor light emitting device packages 11 is, for example, 200 μm.
It can be m. In the first embodiment, the plurality of semiconductor light emitting device packages 11 are formed on the main surface of the underlying growth substrate 1. However, the substrate on which the semiconductor light emitting device packages are arranged has a matrix of semiconductor light emitting device packages. It may be a substrate such as a glass substrate or a plastic substrate arranged in the above, or may be a substrate arranged by transferring the semiconductor light emitting device package from the undergrowth substrate 1 at an increased distance.

As shown in FIG. 4A, the adhesive sheet 12 is laid on the undergrowth substrate 1 on which the semiconductor light emitting device packages 11 are arranged, and as shown in FIG. Semiconductor light emitting device package 11 by applying pressure from
To the adhesive sheet 12. The pressure-sensitive adhesive sheet 12 includes a sheet 13 and a pressure-sensitive adhesive layer 14 formed on the entire surface of the sheet 13. For example, the thickness of the sheet 13 and the pressure-sensitive adhesive layer 14 can be about 100 μm and about 25 μm, respectively. As the sheet 13, vinyl resin, polyolefin resin,
Polyester resin or the like can be used. Since the semiconductor light emitting device packages 11 are selectively arranged on the substrate by irradiating light from the back surface side of the sheet 13 as described later,
The sheet 13 is transparent to this light. Sheet 1
Various materials such as an ultraviolet (UV) curable adhesive agent, a thermosetting adhesive agent, and a thermoplastic adhesive agent can be used for the adhesive layer 14 formed on 3 and, for example, an ultraviolet (UV) curable epoxy agent. Examples include resin and ultraviolet (UV) curable acrylic resin.

When adhering onto the adhesive sheet 12 as described above, the pressure is applied from both sides of the undergrowth substrate 1, and the sheet 13 of the adhesive sheet 12 is a non-flexible material as in the conventional example. Since the semiconductor light emitting device package 11 is made of a flexible material unlike the substrate, the top of the semiconductor light emitting device package 11 does not cross the adhesive layer 14 to reach the sheet 13 and damage the crystal of the semiconductor light emitting device package 11 without causing damage. It is possible to avoid the deterioration of the light emitting performance of No. 11.

After adhering the semiconductor light emitting device package 11 onto the sheet 13 via the adhesive layer 14, the underlying growth substrate 1
Laser light is radiated from the back surface side of FIG. 4C (FIG. 4C) to cause ablation at the interface between the underlying growth substrate 1 and the semiconductor light emitting device package 11 to separate the semiconductor light emitting device package 11 from the underlying growth substrate 1. At this time, when the semiconductor light emitting device package 11 is a GaN-based light emitting semiconductor light emitting device package, it is decomposed into gallium and nitrogen at the interface with the underlying growth substrate 1, so that the semiconductor light emitting device package 11 is relatively deeper than the underlying growth substrate 1. It can be easily separated (Fig. 5 (d)).

An excimer laser, a harmonic YAG laser, or the like is used as the laser light irradiated from the back surface side of the undergrowth substrate 1. When the GaN-based semiconductor light emitting device package 11 is separated from the underlying growth substrate 1 by the laser light, gallium, which hinders conductivity and patterning, is deposited on the separated surface, and thus the gallium is etched. As the etching solution, for example, a sodium hydroxide aqueous solution or dilute nitric acid can be used.

FIG. 5E shows a process of selectively separating the semiconductor light emitting device packages 11 held on the sheet 13 and arranging them on the holding substrate 15 which is the second substrate. The holding substrate 15 is a substrate such as a glass substrate, a quartz glass substrate, or a plastic substrate, and may be a device substrate or a substrate after the element is transferred in the element transfer step. An adhesive layer 17 for adhering the semiconductor light emitting device package 11 is formed on the holding substrate 15. As the adhesive layer 17 on the holding substrate 15, an ultraviolet (UV) curable adhesive, a thermosetting adhesive, a thermoplastic adhesive or the like can be used.

When transferring from the holding substrate 15 to another substrate, a fluorine coating, a silicone resin, a water-soluble adhesive (for example, PVA) may be provided between the adhesive layer 17 and the substrate or on the adhesive layer 17. Alternatively, a peeling layer of polyimide or the like may be formed. When selectively arranging the semiconductor light emitting device packages 11 on the holding substrate 15, first, the sheet 1 for holding the plurality of semiconductor light emitting device packages 11 on the holding substrate 15 is formed.
The semiconductor light emitting device package 11 is stacked on the adhesive layer 17 by stacking three layers.
To adhere. Then, on the sheet 13, a mask 16 is formed by patterning by photolithography in order to irradiate the laser beam and selectively heat the adhesive layer 14. With the mask pattern of the mask 16, when the back surface of the holding substrate 15 is irradiated with light, the adhesive layer 14 can be selectively heated and selectively cured. Light from the back surface side of the holding substrate 15 may be, for example, ultraviolet rays (UV) or infrared rays (IR), depending on the material of the adhesive layer 14.

The semiconductor light emitting device package 11 is selectively placed on the holding substrate 15 by irradiating the holding substrate 15 with light from the surface side.
The adhesive layers 14 on the sheet 13 and the adhesive layer 17 on the holding substrate 15 are selectively arranged due to the difference in adhesiveness between the adhesive layer 14 and the adhesive layer 14 on the holding substrate 15. The positioned semiconductor light emitting device package 11 is separated from the adhesive sheet 12 and arranged on the holding substrate 15 (FIG. 5F).

For example, when an ultraviolet (UV) curable adhesive is used for the adhesive layer 14, the ultraviolet (UV) curable adhesive is cured by being irradiated with ultraviolet (ultraviolet) light and its adhesive property is deteriorated. Therefore, the adhesive layer 14 at the portion opened by the mask 16 and irradiated with the ultraviolet ray (UV) is cured, and the adhesive layer 14 at the portion not irradiated with the ultraviolet ray (UV) by the mask 16 remains uncured. Become. for that reason,
The semiconductor light emitting device package 11 located at a location irradiated with ultraviolet rays (UV) is adhered to the adhesive layer 17 having stronger adhesiveness than the adhesive layer 14 whose adhesiveness is deteriorated by curing, and the holding substrate 1
Ultraviolet rays (UV) are not irradiated to the portions arranged on the upper surface 5 and covered with the mask 16, the adhesive layer 14 is not deteriorated, and the semiconductor light emitting device package 11 remains on the sheet 13.

Further, for example, when a thermosetting adhesive is used for the adhesive layer 14, the thermosetting adhesive has a characteristic that it cures when heat is applied and its adhesiveness deteriorates, so that the mask 16 is opened. The pressure-sensitive adhesive layer 14 in the area irradiated with infrared rays (IR) is cured, and the infrared rays (I
The adhesive layer 14 at the portions not irradiated with R) remains uncured. Therefore, the semiconductor light emitting device package 11 located at the location irradiated with infrared (IR) is arranged on the holding substrate 15 by adhering to the adhesive layer 17 having stronger adhesiveness than the adhesive layer 14 having deteriorated adhesiveness. The semiconductor light emitting device package 11 remains on the sheet 13 without irradiating infrared rays (IR) to the portion covered with and the adhesive layer 14 is not deteriorated.

As described above, the semiconductor light emitting device package 11 on the underlying growth substrate 1 is attached to the adhesive layer 14 of the adhesive sheet 12.
The semiconductor light emitting device package 11 is selectively released from the adhesive sheet 12 after being adhered to and held by the holding substrate 1
5, the semiconductor light emitting device packages 11 are transferred and arranged for the display device. The above-described arrangement of the semiconductor light emitting device packages 11 on the holding substrate 15 is carried out for the semiconductor light emitting device packages 11 that emit red (R) green (G) blue (B) colors. Wiring to the p-side pad electrode 9 and the n-side pad electrode 10 can be performed to manufacture a display device.

The semiconductor light emitting device package 11 functions as a partial pixel (sub-pixel) of each pixel. However, since the semiconductor light emitting device package 11 is formed with a plurality of light emitting portions, light is emitted to a part thereof. Even if a defect occurs, the display device does not have a pixel drop because the other light emitting portions are emitting light. Therefore, it is possible to obtain a good display device without a pixel drop without replacing the defective light emitting element. it can. Further, since the plurality of light emitting units are formed, the emission wavelengths from the plurality of light emitting units are averaged, and it is possible to obtain the display device in which the variation in the emission wavelength of each pixel is reduced and the color unevenness is reduced.

[Second Embodiment] Next, as another embodiment of the semiconductor light emitting device package of the present invention, a semiconductor light emitting device package having a pyramid type light emitting portion will be described below with reference to the drawings. explain. 6A and 6B are plan views showing a configuration of a semiconductor light emitting device package used in the display device of the present invention, FIG. 6A is a plan view, and FIG. 6B is a device sectional view.

This semiconductor light emitting device package is a GaN-based light emitting diode, and is a device which is crystal-grown on the underlying growth substrate 21 which is, for example, a sapphire substrate. The structure of the semiconductor light emitting device package is a hexagonal pyramidal G that is selectively grown on the underlying growth layer 22 made of a GaN-based semiconductor layer.
A plurality of aN layers 23 are formed. Here, an example is shown in which three hexagonal pyramidal GaN layers 23 are formed in a row, but the number and arrangement method of the hexagonal pyramidal GaN layers 23 are not particularly limited. Although the undergrowth substrate 21 is a sapphire substrate, any substrate that can grow a semiconductor layer may be used, and the undergrowth layer 22 and the GaN layer 23 formed on the undergrowth substrate 21 are also GaN-based. Not limited to semiconductors.

An insulating film (not shown) is present on the underlying growth layer 22, and the hexagonal pyramidal GaN layer 23 is formed by MOCVD or the like at the opening of the insulating film. This GaN layer 23 is an S plane (1-101 plane) when the main surface of the sapphire substrate used during growth is the C plane.
This is a pyramid-shaped growth layer covered with, and is a region doped with silicon. The inclined S of the GaN layer 23
The surface part functions as a double heterostructure cladding. An InGaN layer 24, which is an active layer, is formed so as to cover the inclined S surface of the GaN layer 23, and a magnesium-doped GaN layer 25 is formed on the outside thereof. The magnesium-doped GaN layer 25 also functions as a clad.

Further, in a light emitting element having a substantially triangular cross section and a hexagonal pyramid shape as shown in FIG. 6A, a crystal layer is formed by using selective growth to extend in a plane parallel to the inclined crystal plane. Therefore, in order to improve the light emission output of the light emitting device, the GaN layer 2
3 and the amount of impurities doped into the GaN layer 25 is increased, the impurities in the GaN layer 23 and the GaN layer 25 are changed to InGaN.
It is easy to diffuse into the layer 24. Therefore, the InGaN layer 24
In order to avoid the deterioration of the crystal quality of the InGaN layer 24 and the deterioration of the InGaN layer 24, a GaN layer that is not doped with impurities is formed near the InGaN layer 24 of the light emitting device.
The diffusion of impurities into the N layer 24 may be prevented.

In such a light emitting device, a p electrode 26 and an n electrode are provided.
The electrode 27 is formed. The p-electrode 26 is Ni / Pt / Au formed on the magnesium-doped GaN layer 25.
Alternatively, it is formed by depositing a metal material such as Ni (Pd) / Pt / Au. The n-electrode 27 is formed by vapor-depositing a metal material such as Ti / Al / Pt / Au at the opening of the insulating film (not shown). When the n-side electrode is taken out from the back surface side of the underlayer growth layer 22, the formation of the n electrode 27 is not necessary on the front surface side of the underlayer growth layer 22.

On the surface of the underlying growth substrate 21 on which the underlying growth layer 22 and the hexagonal pyramidal GaN layer 23 are formed,
An insulating layer 28 is laminated so as to cover these structures. A p-side hole 29 reaching the p-electrode 26 is formed in the insulating layer 28, and the p-side hole 29 is filled with a metal and electrically connected to the p-electrode 26. The insulating layer 28 has an n-electrode 27.
An n-side hole 30 reaching up to is formed, and the n-side hole 30 is filled with a metal and electrically connected to the n-electrode 27. The p-side pad electrode 31 and the n-side pad electrode 3 are formed on the insulating layer 28.
2 are formed.

Hereinafter, the method for manufacturing the semiconductor light emitting device package of the present embodiment described above will be described with reference to the drawings by an example in which selective growth is performed by a vapor phase growth method using a hexagonal mask. An undergrowth substrate 21 having a 2-inch main surface as the c-plane is installed in an unillustrated metal-organic vapor phase epitaxy apparatus, the surface of the undergrowth substrate 21 is thermally cleaned, and then ammonia as N raw material is placed in a reaction furnace. (N
H ₃ ) and trimethylgallium (T
MGa, Ga (CH ₃ ) ₃ ) is supplied to grow a GaN buffer layer on the underlying growth substrate 21 whose main surface is the c-plane. The GaN buffer layer may be an AlN buffer layer. After the low temperature buffer layer is formed, the underlying growth layer 22 composed of an undoped GaN layer and a silicon (Si) -doped n-type GaN layer is formed at about 1000 ° C. by about 2 μm. Grow (Fig. 7a). The raw material of silicon is silane gas.

After the underlying growth layer 22 is formed, an oxide film 34, which is a growth inhibiting film in which a plurality of hexagonal openings 33 are formed, is arranged on the underlying growth layer 22 (FIG. 7b). The opening diameter of the opening 33 is, for example, 8 μm, and the region other than the opening 33 is covered with the oxide film 34 which is a growth inhibiting film.

A method of forming the oxide film 34 having the hexagonal opening 33 is shown in FIG. The aluminum (Al) plate 35 is oxidized by an anodic oxidation method in an acidic electrolytic solution of sulfuric acid or oxalic acid (not shown) to form an alumina (Al ₂ O ₃ ) layer 36 (FIG. 9a). ).
Since the anodic oxidation is performed in the acidic electrolytic solution, the oxide film is dissolved by the action of the acid, and the alumina layer 36 becomes a porous film (FIG. 9b). The electric field strength in the film thickness direction is increased in the portion where the minute pores 37 are generated due to the dissolution of the alumina layer 36, the dissolution of the oxide film is accelerated, and the thickness of the aluminum plate 35 is decreased due to the dissolution. Then, the growth of the oxide film also progresses (Fig. 9
c).

In this way, the alumina layer 3 which is an oxide film
As a result of the dissolution and growth of 6, the fine pores 37
A porous alumina layer 38 having a large number of is formed. The structure of the porous alumina layer 38 is a structure in which cylindrical alumina of uniform size called a cell 39 is densely packed, and the pores 37 oriented vertically to the film surface are arranged at substantially equal intervals. At the time of anodizing aluminum, it is possible to control the distance between the pores 37 by a voltage and to control the depth of the pores 37 by the time of anodizing.

Naturally formed porous alumina layer 38
Then, by arranging cells 39 hexagonally, hexagonal cells 39
Are formed, and the pores 37 of the cell 39 are expanded by etching, so that the shape of the pore 37 approaches the shape of the cell 39 and becomes a hexagonal shape (FIG. 9d). Finally, by removing the unoxidized aluminum part by etching,
An oxide film 34 having a hexagonal opening 33 is obtained (FIG. 9e).

Then, the underlying growth substrate 21 is installed again in the metal-organic vapor phase epitaxy apparatus, the temperature is raised to about 1020 ° C., and, for example, a mixed gas of H ₂ and N ₂ is used as a carrier gas in the reaction furnace. Ammonia (NH ₃ ) as N raw material and trimethylgallium (TMGa, G as Ga raw material)
a (CH ₃ ) ₃ ) to supply G by selective growth.
The aN layer 23 is grown (FIG. 7c). During this selective growth, the GaN layer 23 is grown from the opening 33 so as to form a direction perpendicular to the main surface of the substrate and an inclined surface outside the opening 33, and along the hexagonal opening 33 of the GaN layer 23. As a result, a slope (S surface) is formed. GaN layer 23 by selective growth
In the middle of the growth, the region sandwiched by the S-planes of the slopes exhibits an upper surface parallel to the main surface of the substrate, and the opening diameter is about 7 μm at a certain point. At this time, trimethylgallium (TMGa) which is a group III source gas is set to about 60 μmol / min.

While the selective growth is continued and the height of the GaN layer 23 is gradually increased by the selective growth, trimethylgallium (TMGa), which is the group III source gas, is reached when the width of the upper surface reaches about 2 μm. The gas supply rate of 1) is reduced to about 15 μmol / min. As a result, the crystallinity of the apex portion has been deteriorated in the past, but in this embodiment, the gas supply rate is reduced to about 15 μmol / min, so that the good crystallinity is obtained.

After forming the GaN layer 23 while lowering the gas supply amount near the apex, the supply of trimethylgallium is temporarily stopped, and then the carrier temperature is all changed to nitrogen gas while the growth temperature is lowered to 730 ° C. , Trimethylgallium as a Ga raw material and trimethylindium as an In raw material are supplied to obtain 30 liters of InGaN.
An InGaN layer 24, which is an active layer, is laminated on the GaN layer 23 (FIG. 7d).

After forming the InGaN layer 24, the temperature is raised while supplying trimethylgallium as a Ga raw material and methylcyclopentadienylmagnesium as a Mg raw material to form a magnesium-doped p-type GaN layer 25, 800
C. Annealing in nitrogen gas is performed to form an n-electrode 27 made of a Ti / Al electrode and a p-electrode 26 made of Ni / Pt / Au.
To form a plurality of light emitting devices (FIG. 8).
e).

Next, using a spin coating technique, photosensitive polyimide is applied to the surface of the undergrowth substrate 1 on which the undergrowth layer 22 and the GaN layer 23 are formed, and then 350 ° C. for 30 minutes in a nitrogen atmosphere. The insulating layer 28 is formed by solidifying the polyimide under the conditions (FIG. 8f).

Next, the insulating layer 28 is patterned by using the photolithography technique to remove the exposed region of the insulating layer 28, and the p-side hole 2 reaching the p-electrode 26.
9 and the n-side hole 30 that reaches the n-electrode 27 are formed in the insulating layer 28 (FIG. 8g).

A p-side hole 29 and an n-side hole 3 are formed on the insulating layer 28.
At a position corresponding to 0, a p-side hole 29 is formed by using a sputtering device.
And the n-side hole 30 is filled with metal. Here, the p-side hole 2
There is no particular limitation on the kind of metal with which the 9 and n-side holes 30 are filled, and a metal such as copper or aluminum used for wiring may be used. After that, titanium / aluminum (Ti / Al) is deposited on the insulating layer 6 by 10/2 using a sputter deposition apparatus.
The p-side pad electrode 31 and the n-side pad electrode 32 are deposited on the insulating layer 28 by depositing it to a thickness of 00 nm, patterning it using a photolithography technique, and etching Al and Ti using phosphoric acid, ammonia, and hydrogen peroxide solution. Are formed (FIG. 8h).

6 to 8, the structure and the manufacturing method of one semiconductor light emitting device package are described. However, a normal semiconductor package or an LED (light-e) is used.
Similar to the manufacturing of the mixing diode, a plurality of packages are collectively formed on one undergrowth substrate, and the individual packages are separated by a dicing process.

By the manufacturing method shown in FIGS. 7 and 8, a plurality of hexagonal pyramidal GaN layers 2 are formed on the underlying growth layer 22.
A semiconductor light emitting device package in which 3 is formed is obtained.
By applying a voltage between the p-side pad electrode 31 and the n-side pad electrode 32, a potential difference is generated between the p-electrode 26 and the n-electrode 27, and the hexagonal pyramidal GaN layer 23 and the InGaN layer 24 are formed.
Since and function as a light emitting element, the semiconductor light emitting element package emits light.

A semiconductor light emitting device package on a base growth substrate is held on an adhesive sheet having an adhesive layer formed on the sheet, and then the semiconductor light emitting device package is selectively arranged on the substrate to manufacture a display device. The semiconductor light emitting device packages are arranged in the same manner as in FIGS. 4 and 5 of the first embodiment. Arrangement is performed for semiconductor light emitting device packages that emit red (R) green (G) blue (B),
The display device can be manufactured by wiring the p-side pad electrode 31 and the n-side pad electrode 32 of each semiconductor light emitting device package.

The semiconductor light emitting device package functions as a partial pixel (sub pixel) of each pixel. However, since a plurality of light emitting portions are formed in the semiconductor light emitting device package, light emission failure occurs in a part thereof. Even if it occurs, it does not become a display device in which pixels are dropped because other light emitting portions are emitting light. Therefore, it is possible to obtain a good display device in which pixels are not dropped without replacing the defective light emitting element. Further, since the plurality of light emitting units are formed, the emission wavelengths from the plurality of light emitting units are averaged, and it is possible to obtain the display device in which the variation in the emission wavelength of each pixel is reduced and the color unevenness is reduced.

[0063]

Third Embodiment Next, as another embodiment of the display device using the light emitting device of the present invention, a plurality of light emitting diodes of the same color system are used to form a partial pixel (sub pixel) of the display device. The case of forming will be described below with reference to the drawings.

As shown in FIG. 10, in the display device of this embodiment, light emitting diodes 41 for emitting light corresponding to red (R) green (G) blue (B) are arranged in a matrix on a holding substrate 40. Then, wiring is formed in each light emitting diode 41, and a drive voltage is applied to each light emitting diode 41 to display an image. Pixel 4 which is the minimum unit for emitting color light in the combination of RGB surrounded by a broken line frame in the figure
2 includes a plurality of light emitting diodes 41 corresponding to RGB colors. That is, the sub-pixel 43 is formed by the light-emitting diode 41 of the same color enclosed by the broken line frame in the drawing included in the pixel, and the pixel 42 is formed by the sub-pixel 43 of each color of RGB.

FIG. 11 is a plan view showing the structure of the light emitting diode 41 used in the display device of the present invention.
1 (a) is a plan view and FIG. 11 (b) is a front view. Although the structure is similar to that of the semiconductor light emitting device package according to the first embodiment described above, the number of light emitting devices formed in each package is one in this embodiment.

An n layer 5 in which a plurality of GaN-based semiconductors are n-type-doped on a base growth substrate 51 which is a sapphire substrate.
2 is formed, an n-electrode 53 and a p-type doped p-layer 54 are formed on the n-layer 52, and a p-type p is formed on the p-layer 54.
The electrode 55 is formed. Further, although the underlying growth substrate 51 is a sapphire substrate, any substrate that can grow a semiconductor layer may be used, and the n layer 52 and the p layer 54 formed on the underlying growth substrate 51 are also GaN-based semiconductors. Not limited to

On the surface of the underlying growth substrate 51 on which the n-electrode 53, the p-layer 54 and the p-electrode 55 are formed, an insulating layer 56 is laminated so as to cover these structures. A p-side hole 57 reaching the p-electrode 55 is formed in the insulating layer 56, and the p-side hole 57 is filled with a metal and electrically connected to the p-electrode 55. In addition, an n-side hole 58 reaching the n-electrode 53 is formed in the insulating layer 56, and the n-side hole 58 is filled with a metal and electrically connected to the n-electrode 53. A p-side pad electrode 59 and an n-side pad electrode 60 are formed on the insulating layer 56.
And are formed.

The method for manufacturing the light emitting diode 41 described above is the same as the method for manufacturing the semiconductor light emitting device package according to the first embodiment described above, and will be described with reference to FIGS. 2 and 3. Here, as in the case of manufacturing a normal light emitting diode, a plurality of packages are collectively formed on one undergrowth substrate, and the individual packages are separated by a dicing process.

In the present embodiment, an example in which five sub-pixels 43 are formed by arranging five light-emitting diodes 41 with different grown undergrowth substrates is shown.
This is for averaging the emission wavelength of 1 and the luminance, and therefore the number is not limited as long as a plurality of light emitting diodes form a subpixel. Further, an example in which the light emitting diode 41 is formed by a pair of the n layer 52 and the p layer 54 is shown, but using the semiconductor light emitting device package in which a plurality of p layers are formed on the n layer shown in the first embodiment is used. Alternatively, as shown in the second embodiment, a semiconductor light emitting device package in which a plurality of hexagonal pyramidal light emitting devices are formed may be used.

The light emitting diode 41 in which the p layer 54 is formed on the n layer 52 is obtained by the steps similar to the manufacturing method shown in FIGS. By applying a voltage between the p-side pad electrode 59 and the n-side pad electrode 60, a potential difference is generated between the p-electrode 55 and the n-electrode 53 of the p-layer 54, and the p-layer 5
Since the combination of 4 and the n layer 52 functions as a light emitting element, the light emitting diode 41 emits light.

The light emitting diode 41 on the underlying growth substrate is
A method of arranging light emitting diodes for manufacturing a display device by holding light emitting diodes 41 on a substrate and then selectively arranging the light emitting diodes 41 on the substrate will be described. In the same manner as described with reference to FIGS. 4 and 5 in the first embodiment, after the light emitting diode 41 on the undergrowth substrate is adhered and held on the adhesive layer of the adhesive sheet, the light emitting diode 41 is attached to the adhesive sheet. By selectively detaching from and arranging on the holding substrate 40, the light emitting diodes 41 are transferred and arranged for the display device.

The rule of arrangement of the light emitting diodes 41 on the holding substrate 40 when transferring the light emitting diodes 41 will be described with reference to FIG. Multiple adhesive sheets 44
Light-emitting diodes formed on the underlying growth substrate are separated and held by dicing in a to 44e. The light emitting diodes held by the adhesive sheets 44a to 44e are all designed to emit light of the same color, and are blue light emitting diodes as an example. Further, it is assumed that the plurality of light emitting diodes 41 formed on the same underlying growth substrate are held on the same adhesive sheet.

The light emitting diode 41 is attached to the adhesive sheets 44a ...
When transferring from 44e to the holding substrate 40, a plurality of light emitting diodes of the same color system included in the same subpixel 43 are extracted from each adhesive sheet 44a to 44e and arranged. More specifically, after transferring the light emitting diode 41 held by the adhesive sheet 44a to a predetermined area of each sub-pixel 43 and arranging it, the light emitting diode held by another adhesive sheet is moved in a predetermined area. Transfer to and place. By repeating this process up to the adhesive sheet 44e, it becomes possible to disperse and arrange the light emitting diodes 41 held by the plurality of adhesive sheets in the respective sub-pixels 43.

The above-described arrangement of the light emitting diodes 41 on the holding substrate 40 is carried out for the light emitting diodes 41 which emit the respective colors of red (R) green (G) blue (B). Wiring is performed to the side pad electrode 59 and the n-side pad electrode 60 to manufacture a display device.

Since a plurality of light emitting diodes 41 are formed in the sub-pixel 43, even if a defective light emission occurs in a part of the sub-pixels 43, the other light emitting diodes 41 are emitting light and the display device has a pixel drop. Therefore, it is possible to obtain a good display device with no pixel drop even if the defective light emitting element is not replaced.

In general, even when the light emitting diode is crystal-grown under the same conditions, the characteristics of the emission wavelength and the emission luminance may differ between the underlying growth substrates. However, since a plurality of light emitting diodes 41 are arranged in the sub-pixel 43 of each pixel 42, and the light emitting diodes 41 in the sub-pixels 43 are light emitting diodes grown from different undergrowth substrates, they are derived from the grown undergrowth substrate. It is possible to obtain the sub-pixel 43 in which the difference between the emission wavelength and the brightness is averaged. As a result, it is possible to obtain a display device in which variations in emission wavelength and luminance between pixels are reduced and color unevenness is reduced.

[0077]

Since the sub-pixel is formed by a plurality of light-emitting elements that emit light of substantially the same color, even if some of the light-emitting elements in the sub-pixel have a light emission failure or a color development failure, Since the pixel itself does not have a light emission failure or a color development failure, it is possible to reduce pixel defects and color unevenness without replacing the pixels of the display device.

By configuring a sub-pixel by a plurality of light emitting elements formed on different semiconductor growth substrates, even if there is a bias due to the semiconductor growth substrate in the characteristics of the emission wavelength and the brightness of the light emitting elements, the sub pixel Since the emission wavelength and the luminance are averaged in the pixel, it is possible to perform display with reduced color unevenness.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a semiconductor light emitting device package according to a first embodiment of the present invention, FIG. 1 (a) is a plan view, and FIG. 1 (b) is a front view.

FIG. 2 is a first half of a process diagram showing a method for manufacturing the semiconductor light emitting device package shown in FIG.

FIG. 3 is the second half of the process chart showing the method for manufacturing the semiconductor light emitting device package shown in FIG.

FIG. 4 is a first half of a process diagram showing an arrangement method for selectively transferring and arranging a semiconductor light emitting device package onto another substrate.

FIG. 5 is a second half of a process diagram showing an arrangement method for selectively transferring and arranging a semiconductor light emitting device package on another substrate.

6A and 6B are diagrams showing a configuration of a semiconductor light emitting device package according to a second embodiment of the present invention, wherein FIG. 6A is a plan view and FIG. 6B is a front view.

7 is a first half of a process diagram showing a method of manufacturing the semiconductor light emitting device package shown in FIG.

FIG. 8 is the second half of the process chart showing the method for manufacturing the semiconductor light emitting device package shown in FIG.

FIG. 9 is a diagram schematically showing a step of forming an oxide film and an opening used as a mask for selective growth in Embodiment 2 by an anodic oxidation method of aluminum.

FIG. 10 is a plan view showing a display device according to a third embodiment of the present invention, in which sub-pixels are formed by a plurality of light emitting diodes of the same color.

FIG. 11 is a diagram showing a configuration of a light emitting diode according to a third embodiment of the present invention, FIG. 11 (a) is a plan view, and FIG. 11 (b) is a front view.

FIG. 12 is a schematic diagram showing an arrangement rule in transferring the light emitting diodes to the holding substrate in the third embodiment.

[Explanation of symbols] 1, 21, 51 Undergrowth substrate 2,52 n layers 3, 27, 53 n-electrode 4, 54 p-layer 5, 26, 55 p electrode 6, 28, 56 Insulation layer 7, 29, 57 p side hole 8, 30, 58 n side hole 9, 31, 59 p-side pad electrode 10, 32, 60 n-side pad electrode 11 Semiconductor light emitting device package 12 Adhesive sheet 13 sheets 14,17 Adhesive layer 15, 40 holding substrate 16 masks 22 Underlayer 23 GaN layer 24 InGaN layer 25 GaN layer 33 opening 34 Oxide film 35 Aluminum plate 36 Alumina layer 37 pores 38 Porous alumina layer 39 cells 41 light emitting diode 42 pixels 43 sub pixels 44 Adhesive sheet

Continued front page    F term (reference) 5C094 AA03 AA41 BA23 CA19 CA24                       FB14                 5F041 AA14 AA41 CA02 CA04 CA10                       CA34 CA40 CA46 CA65 CA74                       DA14 DA20 DA82 DB08 FF01

Claims (9)

[Claims] 1. Pixels formed by combining partial pixels that emit different colors are arranged in a matrix on a holding substrate, and the partial pixels are formed by a plurality of light emitting elements that emit light of substantially the same color. A display device characterized by the above. 2. The display device according to claim 1, wherein the plurality of light emitting elements are formed on the same light emitting element package. 3. A plurality of second semiconductor growth layers are formed on the first semiconductor growth layer, and the plurality of second semiconductor growth layers are combined by a combination of the first semiconductor growth layer and the plurality of second semiconductor growth layers. The display device according to claim 2, wherein a light emitting element is formed. 4. The display device according to claim 1, wherein the plurality of light emitting elements forming the partial pixel are light emitting elements crystal-grown on different semiconductor growth substrates. 5. The display device according to claim 1, wherein the plurality of light emitting elements are light emitting diodes or semiconductor lasers. 6. The display device according to claim 1, wherein the plurality of light emitting elements are semiconductor light emitting elements containing gallium nitride as a main component. 7. A step of forming light emitting elements on a plurality of semiconductor growth substrates, and a step of transferring the light emitting elements from the plurality of semiconductor growth substrates to one partial pixel forming a pixel on a holding substrate. A method for manufacturing a display device, comprising: 8. The step of transferring the light emitting elements from the plurality of semiconductor growth substrates to the partial pixels further includes an adhesive sheet having an adhesive layer formed on the light emitting elements formed on the semiconductor growth substrate. A step of fixing the array above, a step of allowing the light emitting elements to be transferred among the fixed light emitting elements to be peeled off from the adhesive sheet, and a transfer object removable from the adhesive sheet. 8. The method for manufacturing a display device according to claim 7, further comprising the step of: transferring the light emitting element to a holding substrate provided with another adhesive layer. 9. The adhesive layer formed on the adhesive sheet is made of a thermoplastic material, and the position of the adhesive layer corresponding to the light emitting element to be transferred is heated to change the light emitting element to be transferred. The method for manufacturing a display device according to claim 8, wherein the display device is removable from the adhesive sheet.