Light-emitting device, electronic apparatus, and manufacturing method of the light-emitting device

Abstract

To provide a light-emitting device capable of reducing a distance between a first pixel electrode and a second pixel electrode.SOLUTION: A light-emitting device comprises: a substrate; a plurality of column-like parts; a first conductive type first conductor layer that is provided so as to be overlapped with the plurality of column-like parts; a first pixel electrode that is provided between a plurality of first column-like parts of the plurality of column-like parts and the substrate; a second pixel electrode that is provided between a plurality of second column-like parts of the plurality of column-like parts and the substrate, and is separated from the first pixel electrode; and a common electrode that is provided to the side opposite to the substrate of the first semiconductor layer. Each of the plurality of column-like parts includes: a second conductive type second conductor layer that is different from the first conductive type; a third semiconductor layer of the first conductive type, to be provided between the first semiconductor layer and the second semiconductor layer; and a quantum well layer that is provided between the second semiconductor layer and the third semiconductor layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a light-emitting device, an electronic device, and a method for manufacturing a light-emitting device.

Background Art

[0002] Light-emitting elements such as LEDs (Light Emitting Diodes) are applied to light sources such as display devices.

[0003] For example, Patent Document 1 describes that in an image display element in which micro light-emitting elements are arranged in an array, the micro light-emitting elements include an excitation light-emitting element that generates excitation light, a reflective wall surrounding the excitation light-emitting element, and a wavelength conversion material disposed inside the reflective wall.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the image display device as described above, in order to increase the resolution, it is necessary to integrate excitation light-emitting elements at a high density. In the image display device described in Patent Document 1, since a reflective wall is provided between adjacent excitation light-emitting elements, it is difficult to reduce the distance between adjacent excitation light-emitting elements.

Means for Solving the Problems

[0006] One aspect of the light-emitting device according to the present invention is a substrate, a plurality of columnar portions, a first semiconductor layer of a first conductivity type provided so as to overlap the plurality of columnar portions, A first pixel electrode provided between a plurality of first columnar portions among the plurality of columnar portions and the substrate; A second pixel electrode provided between a plurality of second columnar portions among the plurality of columnar portions and the substrate and spaced apart from the first pixel electrode; A common electrode provided on the side of the first semiconductor layer opposite to the substrate; and comprising Each of the plurality of columnar portions has a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type provided between the first semiconductor layer and the second semiconductor layer, and a quantum well layer provided between the second semiconductor layer and the third semiconductor layer.

[0007] One aspect of the electronic device according to the present invention has one aspect of the light-emitting device.

[0008] One aspect of the method for manufacturing a light-emitting device according to the present invention includes a step of forming a first semiconductor layer of a first conductivity type on a first substrate, a step of forming a plurality of columnar portions on the first semiconductor layer, a step of forming a first pixel electrode over a plurality of first columnar portions among the plurality of columnar portions and forming a second pixel electrode over a plurality of second columnar portions among the plurality of columnar portions, a step of bonding a structure having the first substrate, the first semiconductor layer, the plurality of columnar portions, the first pixel electrode, and the second pixel electrode to a second substrate with the first pixel electrode and the second pixel electrode sides facing the second substrate, a step of removing the first substrate to expose the first semiconductor layer, and a step of forming a common electrode on the first semiconductor layer. and comprising In the step of forming the plurality of columnar portions, ​​Form the plurality of columnar portions having a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type, and a quantum well layer provided between the second semiconductor layer and the third semiconductor layer.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0011] 1. Light-emitting device 1.1. Configuration First, the light-emitting device according to the present embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the light-emitting device 100 according to the present embodiment. FIG. 2 is a plan view schematically showing the light-emitting device 100 according to the present embodiment. Note that FIG. 1 is a cross-sectional view taken along line I-I of FIG. 2.

[0012] As shown in FIGS. 1 and 2, the light-emitting device 100 includes, for example, a driving substrate 10, a pixel electrode 20, a columnar portion 30, a mask layer 40, a first semiconductor layer 50, and a common electrode 60.

[0013] The driving substrate 10 is, for example, a Si substrate provided with a driving circuit. The driving circuit is a circuit for driving the light-emitting device 100. The driving circuit is, for example, composed of an IC (Integrated Circuit). The driving circuit has a pad electrode 12. The material of the pad electrode 12 is metal. A plurality of pad electrodes 12 are provided corresponding to a plurality of pixel electrodes 20.

[0014] ​As shown in FIG. 1, the pixel electrode 20 is provided on the driving substrate 10. The pixel electrode 20 is provided between the driving substrate 10 and the plurality of columnar portions 30. The pixel electrode 20 is provided on the pad electrode 12. The pixel electrode 20 is electrically connected to the driving circuit and the second semiconductor layer 32 of the columnar portion 30. The material of the pixel electrode 20 is, for example, a metal. Specifically, the pixel electrode 20 is composed of a titanium layer, an aluminum layer, or a laminate thereof. The pixel electrode 20 is one of the electrodes for injecting current into the quantum well layer 34. The pixel electrode 20 reflects the light generated in the quantum well layer 34 of the columnar portion 30 toward the first semiconductor layer 50 side.

[0015] A plurality of pixel electrodes 20 are provided. In the example shown in FIG. 2, the plurality of pixel electrodes 20 are arranged in a matrix. The plurality of pixel electrodes 20 are spaced apart from each other. The planar shape of the pixel electrode 20 is, for example, a quadrangle. Among the plurality of pixel electrodes 20, the first pixel electrode 20a and the second pixel electrode 20b are adjacent to each other. The pixel electrode 20, the columnar portion 30, the first semiconductor layer 50, and the common electrode 60 constitute a plurality of light emitting elements 102. The light emitting element 102 is, for example, an LED (Light Emitting Diode).

[0016] As shown in FIG. 1, the columnar portion 30 is provided between the driving substrate 10 and the first semiconductor layer 50. The columnar portion 30 is also called, for example, a nanocolumn, a nanowire, a nanorod, or a nanopillar. The planar shape of the columnar portion 30 is, for example, a polygon such as a regular hexagon or a circle.

[0017] The diameter of the columnar portion 30 is, for example, 50 nm or more and 500 nm or less, preferably 100 nm or more and 200 nm or less. By setting the diameter of the columnar portion 30 to 500 nm or less, a high-quality crystal quantum well layer 34 can be obtained, and the strain inherent in the quantum well layer 34 can be reduced.

[0018] Note that the "diameter of the columnar portion 30" is the diameter when the planar shape of the columnar portion 30 is a circle, and is the diameter of the minimum circumscribed circle when the planar shape of the columnar portion 30 is not a circle. For example, when the planar shape of the columnar portion 30 is a polygon, the diameter of the columnar portion 30 is the diameter of the smallest circle that contains the polygon inside, and when the planar shape of the columnar portion 30 is an ellipse, the diameter of the columnar portion 30 is the diameter of the smallest circle that contains the ellipse inside.

[0019] A plurality of columnar portions 30 are provided. The plurality of columnar portions 30 are spaced apart from each other. In the illustrated example, there is a gap between adjacent columnar portions 30. Although not shown, the space between adjacent columnar portions 30 may be filled with an insulating layer. The interval between adjacent columnar portions 30 is, for example, 1 nm or more and 500 nm or less. The plurality of columnar portions 30 are arranged at a predetermined pitch in a predetermined direction in a plan view. The plurality of columnar portions 30 are arranged at a predetermined pitch in a predetermined direction when viewed from the stacking direction of the second semiconductor layer 32 and the quantum well layer 34. The plurality of columnar portions 30 are arranged, for example, in a regular triangular lattice or a square lattice. The diameter and pitch of the plurality of columnar portions 30 are designed such that the photonic crystal formed thereby does not propagate light of the emission wavelength in the in-plane direction and is extracted in the vertical direction.

[0020] Note that the "pitch of the columnar portion 30" is the distance between the centers of adjacent columnar portions 30 in a predetermined direction. The "center of the columnar portion 30" is the center of the circle when the planar shape of the columnar portion 30 is a circle, and is the center of the minimum circumscribed circle when the planar shape of the columnar portion 30 is not a circle. For example, when the planar shape of the columnar portion 30 is a polygon, the center of the columnar portion 30 is the center of the smallest circle that contains the polygon inside, and when the planar shape of the columnar portion 30 is an ellipse, the center of the columnar portion 30 is the center of the smallest circle that contains the ellipse inside.

[0021] Among the plurality of columnar portions 30, the first columnar portion 30a is provided on the first pixel electrode 20a. The first columnar portion 30a is provided between the first pixel electrode 20a and the first semiconductor layer 50. The first columnar portion 30a protrudes upward from the first pixel electrode 20a. In plan view, the first columnar portion 30a overlaps the first pixel electrode 20a. The first columnar portion 30a is provided on the driving substrate 10 via the first pixel electrode 20a. A plurality of the first columnar portions 30a are provided. The first pixel electrode 20a is provided between the plurality of first columnar portions 30a and the driving substrate 10.

[0022] Among the plurality of columnar portions 30, the second columnar portion 30b is provided on the second pixel electrode 20b. The second columnar portion 30b is provided between the second pixel electrode 20b and the first semiconductor layer 50. The second columnar portion 30b protrudes upward from the second pixel electrode 20b. In plan view, the second columnar portion 30b overlaps the second pixel electrode 20b. The second columnar portion 30b is provided on the driving substrate 10 via the first pixel electrode 20a. A plurality of the second columnar portions 30b are provided. The second pixel electrode 20b is provided between the plurality of second columnar portions 30b and the driving substrate 10.

[0023] Among the plurality of columnar portions 30, the third columnar portion 30c is not provided on the pixel electrode 20. The third columnar portion 30c is provided in a region on the driving substrate 10 where the pixel electrode 20 is not provided, on an insulating layer (e.g., SiO 2) is provided on the driving substrate 10 via []. Therefore, the third columnar portion 30c is insulated from the driving substrate 10. Also, the space between the third columnar portion 30c and the driving substrate 10 may be in a floating state instead of being provided via an insulating layer as described above. A plurality of the third columnar portions 30c are provided. The third columnar portion 30c is provided between adjacent pixel electrodes 20 in a plan view. The third columnar portion 30c is provided between the first pixel electrode 20a and the second pixel electrode 20b in a plan view. The plurality of third columnar portions 30c surround the plurality of first columnar portions 30a in a plan view. Further, the plurality of third columnar portions 30c surround the plurality of second columnar portions 30b in a plan view. The plurality of third columnar portions 30c surround the plurality of pixel electrodes 20 in a plan view. The pitches of the plurality of first columnar portions 30a, the pitches of the plurality of second columnar portions 30b, and the pitches of the plurality of third columnar portions 30c are, for example, the same as each other.

[0024] The columnar portion 30 has a second semiconductor layer 32, a quantum well layer 34, and a third semiconductor layer 36. The second semiconductor layer 32, the quantum well layer 34, and the third semiconductor layer 36 are, for example, group III nitride semiconductors and have a wurtzite crystal structure.

[0025] The second semiconductor layer 32 is provided between the driving substrate 10 and the quantum well layer 34. The second semiconductor layer 32 is a semiconductor layer of a second conductivity type different from the first conductivity type. The second conductivity type is, for example, p-type. The second semiconductor layer 32 is, for example, a p-type GaN layer doped with Mg.

[0026] The quantum well layer 34 is provided on the second semiconductor layer 32. The quantum well layer 34 is provided between the second semiconductor layer 32 and the third semiconductor layer 36. The quantum well layer 34 generates light when current is injected. Current is injected into the quantum well layer 34 of the columnar portion 30 that overlaps with the pixel electrode 20 in plan view. Therefore, the quantum well layer 34 of the columnar portion 30 that overlaps with the pixel electrode 20 in plan view generates light. On the other hand, no current is injected into the quantum well layer 34 of the third columnar portion 30c that does not overlap with the pixel electrode 20 in plan view. Therefore, no light is generated in the quantum well layer 34 of the third columnar portion 30c.

[0027] The quantum well layer 34 has, for example, a well layer and a barrier layer. The well layer and the barrier layer are i-type semiconductor layers into which impurities are not intentionally doped. The well layer is, for example, an InGaN layer. The barrier layer is, for example, a GaN layer. The quantum well layer 34 has a MQW (Multiple Quantum Well) structure composed of a well layer and a barrier layer.

[0028] Note that the number of well layers and barrier layers constituting the quantum well layer 34 is not particularly limited. For example, only one well layer may be provided, and in this case, the quantum well layer 34 has a SQW (Single Quantum Well) structure. Also, although not shown, an EBL (Electron Blocking Layer) made of a p-type AlGaN layer may be provided between the second semiconductor layer 32 and the quantum well layer 34.

[0029] The third semiconductor layer 36 is provided on the quantum well layer 34. The third semiconductor layer 36 is provided between the quantum well layer 34 and the first semiconductor layer 50. The third semiconductor layer 36 is provided between the second semiconductor layer 32 and the first semiconductor layer 50. The third semiconductor layer 36 is a semiconductor layer of the first conductivity type. The first conductivity type is, for example, n-type. The third semiconductor layer 36 is, for example, an n-type GaN layer doped with Si. The second semiconductor layer 32 and the third semiconductor layer 36 are cladding layers having a function of confining light in the quantum well layer 34.

[0030] In the light-emitting device 100, a pin diode is formed by a p-type second semiconductor layer 32, an i-type quantum well layer 34 that is not intentionally doped with impurities, and an n-type third semiconductor layer 36. In the light-emitting device 100, when a forward bias voltage of the pin diode is applied between the pixel electrode 20 and the common electrode 60 by the drive circuit of the drive substrate 10, current is injected into the quantum well layer 34, and recombination of electrons and holes occurs in the quantum well layer 34. Light emission is caused by this recombination. The light generated in the quantum well layer 34 does not propagate laterally due to the effect of the photonic crystal formed by the plurality of columnar portions 30, and is emitted in the vertical direction, that is, the up-and-down direction. The pixel electrode 20 reflects the light emitted downward upward.

[0031] The mask layer 40 is provided around the columnar portion 30. It is provided under the first semiconductor layer 50. The thickness of the mask layer 40 is, for example, 1 nm or more and 10 nm or less, preferably 2 nm or more and 8 nm or less. If the thickness of the mask layer 40 is 10 nm or less, light absorption in the mask layer 40 can be reduced. The mask layer 40 is, for example, a Ti layer, a TiO 2 layer, a SiO 2 layer. The mask layer 40 is a mask for growing the columnar portion 30.

[0032] The first semiconductor layer 50 is provided on the plurality of columnar portions 30. The first semiconductor layer 50 is provided on the side opposite to the drive substrate 10 of the plurality of columnar portions 30. The first semiconductor layer 50 is provided across the plurality of columnar portions 30. The first semiconductor layer 50 is provided between the plurality of columnar portions 30 and the common electrode 60. The first semiconductor layer 50 is provided so as to overlap the plurality of columnar portions 30. The first semiconductor layer 50 is a semiconductor layer of the first conductivity type. The first semiconductor layer 50 is, for example, an n-type GaN layer doped with Si.

[0033] The common electrode 60 is provided on the first semiconductor layer 50. The common electrode 60 is provided on the side of the first semiconductor layer 50 opposite to the driving substrate 10. As shown in FIG. 2, for example, in a plan view, the common electrode 60 does not overlap with the pixel electrode 20. In a plan view, for example, the common electrode 60 surrounds a plurality of pixel electrodes 20.

[0034] The common electrode 60 is electrically connected to the third semiconductor layer 36 of the columnar portion 30 through the first semiconductor layer 50. The first semiconductor layer 50 may be in ohmic contact with the common electrode 60. Although not shown, the common electrode 60 is electrically connected to a driving circuit provided on the driving substrate 10 through wire bonding or the like. The common electrode 60 is laminated in the order of a Pd layer, a Pt layer, a Ni layer, and an Au layer from the first semiconductor layer 50 side, or is a single layer of a metal layer. The common electrode 60 is the other electrode for injecting current into the quantum well layer 34.

[0035] In the above description, the InGaN-based quantum well layer 34 has been described. However, as the quantum well layer 34, various material systems capable of emitting light by injecting current can be used according to the wavelength of the emitted light. For example, semiconductor materials such as AlGaN-based, AlGaAs-based, InGaAs-based, InGaAsP-based, InP-based, GaP-based, and AlGaP-based can be used.

[0036] In the above description, an example in which the first conductivity type is n-type and the second conductivity type is p-type has been described. However, the first conductivity type may be p-type and the second conductivity type may be n-type.

[0037] 1.2. Operational Effects In the light-emitting device 100, a driving substrate 10, a plurality of columnar portions 30, a first semiconductor layer 50 of a first conductivity type provided so as to overlap the plurality of columnar portions 30, a plurality of first columnar portions 30a among the plurality of columnar portions 30, a first pixel electrode 20a provided between the driving substrate 10 and the plurality of first columnar portions 30a, a plurality of second columnar portions 30b among the plurality of columnar portions 30, a second pixel electrode 20b provided between the driving substrate 10 and the plurality of second columnar portions 30b and separated from the first pixel electrode 20a, and a common electrode 60 provided on the side of the first semiconductor layer 50 opposite to the driving substrate 10 are included. Each of the plurality of columnar portions 30 has a second semiconductor layer 32 of a second conductivity type different from the first conductivity type, a third semiconductor layer 36 of the first conductivity type provided between the first semiconductor layer 50 and the second semiconductor layer 32, and a quantum well layer 34 provided between the second semiconductor layer 32 and the third semiconductor layer 36.

[0038] Therefore, in the light-emitting device 100, highly directional light can be emitted in the vertical direction due to the photonic crystal effect of the plurality of columnar portions 30. Thereby, high efficiency can be achieved without providing a reflective wall between the first pixel electrode 20a and the second pixel electrode 20b. Therefore, the distance between the first pixel electrode 20a and the second pixel electrode 20b can be reduced. Thus, the light-emitting elements 102 can be integrated at high density.

[0039] In the light-emitting device 100, the common electrode 60 does not overlap the first pixel electrode 20a and the second pixel electrode 20b in plan view. Therefore, in the light-emitting device 100, the common electrode 60 can reduce the possibility that the light generated in the quantum well layer 34 is absorbed.

[0040] In the light-emitting device 100, the materials of the first pixel electrode 20a and the second pixel electrode 20b are metals having a high reflectivity with respect to the emission wavelength. For example, it is Al. Therefore, in the light-emitting device 100, the first pixel electrode 20a can reflect the light generated in the quantum well layer 34 of the first columnar portion 30a. Further, the second pixel electrode 20b can reflect the light generated in the quantum well layer 34 of the second columnar portion 30b.

[0041] In the light-emitting device 100, among the plurality of columnar portions 30, the third columnar portion 30c is provided between the first pixel electrode 20a and the second pixel electrode 20b in a plan view. Thus, in the light-emitting device 100, in order to separate the light-emitting element 102 having the first pixel electrode 20a and the light-emitting element 102 having the second pixel electrode 20b, the third columnar portion 30c provided between the first pixel electrode 20a and the second pixel electrode 20b in a plan view is not removed. Therefore, the structure of the light-emitting device 100 can be simplified.

[0042] 2. Manufacturing Method of Light-Emitting Device Next, a method for manufacturing the light-emitting device 100 according to the present embodiment will be described with reference to the drawings. FIG. 3 is a flowchart for explaining the manufacturing method of the light-emitting device 100 according to the present embodiment. FIGS. 4 to 9 are cross-sectional views schematically showing the manufacturing process of the light-emitting device 100 according to the present embodiment.

[0043] As shown in FIGS. 3 and 4, a first semiconductor layer 50 is formed on a growth substrate 70 (step S1). Specifically, the first semiconductor layer 50 is epitaxially grown on the growth substrate 70. Examples of the epitaxial growth method include a MOCVD (Metal Organic Chemical Vapor Deposition) method and an MBE (Molecular Beam Epitaxy) method. The growth substrate 70 is, for example, a sapphire substrate, a Si substrate, or a SiC substrate. The upper surface of the growth substrate 70 is, for example, a c-plane.

[0044] As shown in FIG. 5, a mask layer 40 is formed on the first semiconductor layer 50 (step S2). The mask layer 40 is formed, for example, by a CVD (Chemical Vapor Deposition) method, an EB (electron beam) evaporation method, or a sputtering method. Next, the mask layer 40 is patterned to form a plurality of openings 42. The planar shape of the opening 42 is, for example, circular. The patterning is performed, for example, by resist patterning using electron beam lithography and dry etching. Note that the patterning may be performed using photolithography or nanoimprint lithography. In the patterning, a lift-off method may be used instead of etching.

[0045] As shown in FIG. 6, a plurality of columnar portions 30 are formed on the first semiconductor layer 50 (step S3). Specifically, using the mask layer 40 as a mask, a second semiconductor layer 32, a quantum well layer 34, and a third semiconductor layer 36 are epitaxially grown on the first semiconductor layer 50 in this order. The epitaxial growth is performed, for example, by an MBE method using RF (radio frequency) plasma as a nitrogen material source. By using appropriate conditions for the substrate temperature and the material irradiation amount, crystal deposition on the mask layer 40 can be suppressed, and crystals can be selectively grown in the openings 42.

[0046] As shown in FIG. 7, a plurality of pixel electrodes 20 are formed on the plurality of columnar portions 30 (step S4). In this step, a first pixel electrode 20a is formed over the plurality of first columnar portions 30a, and a second pixel electrode 20b is formed over the plurality of second columnar portions 30b. The pixel electrode 20 is formed by an EB evaporation method and patterning. The patterning is performed, for example, by photolithography and etching. In the patterning, a lift-off method may be used instead of etching.

[0047] Through the above steps, a structure 110 having a growth substrate 70, a first semiconductor layer 50, a mask layer 40, a plurality of columnar portions 30, and a plurality of pixel electrodes 20 can be formed.

[0048] Although not shown in the drawings, when an insulating layer is embedded between a plurality of columnar portions 30, the insulating layer is formed, for example, by an atomic layer deposition (ALD) method.

[0049] As shown in FIG. 8, the structure 110 is bonded to the driving substrate 10 with the pixel electrode 20 side facing the driving substrate 10 (step S5). Specifically, the pad electrode 12 and the pixel electrode 20 are aligned and then bonded together. The bonding is performed by applying pressure or heat treatment. The structure 110 is, for example, junction-down mounted on the driving substrate 10. The driving circuit of the driving substrate 10 is formed by ion implantation of impurities into the Si substrate, formation of an SiO 2 layer, patterning of the pad electrode 12, and the like.

[0050] As shown in FIG. 9, the growth substrate 70 is removed to expose the first semiconductor layer 50 (step S6). When the growth substrate 70 is a sapphire substrate, the growth substrate 70 is removed by a laser lift-off method. When the growth substrate 70 is a Si substrate, the growth substrate 70 is removed by polishing or a wet etching method.

[0051] As shown in FIG. 1, the first semiconductor layer 50 is thinned (step S7). Examples of the method for thinning include a Chemical Mechanical Polishing (CMP) method.

[0052] Next, a common electrode 60 is formed on the first semiconductor layer 50 (step S8). The common electrode 60 is formed, for example, by a CVD method, an EB evaporation method, or a sputtering method. Thereafter, the common electrode 60 and the driving circuit of the driving substrate 10 are electrically connected by wire bonding (not shown).

[0053] Through the above steps, the light-emitting device 100 can be manufactured.

[0054] In the manufacturing method of the light-emitting device 100, the steps include forming a first semiconductor layer 50 on a growth substrate 70 as a first substrate, forming a plurality of columnar portions 30 on the first semiconductor layer 50, forming a first pixel electrode 20a over a plurality of first columnar portions 30a among the plurality of columnar portions 30, forming a second pixel electrode 20b over a plurality of second columnar portions 30b among the plurality of columnar portions 30, bonding a structure 110 to a driving substrate 10 as a second substrate with the sides of the first pixel electrode 20a and the second pixel electrode 20b facing the driving substrate 10, removing the growth substrate 70 to expose the first semiconductor layer 50, and forming a common electrode 60 on the first semiconductor layer 50. In the step of forming the plurality of columnar portions 30, a plurality of columnar portions 30 having a second semiconductor layer 32, a third semiconductor layer 36, and a quantum well layer 34 are formed. Therefore, in the manufacturing method of the light-emitting device 100, the distance between the first pixel electrode 20a and the second pixel electrode 20b can be reduced.

[0055] 3. Modification Example of Light-Emitting Device 3.1. First Modification Example Next, a light-emitting device according to the first modification example of the present embodiment will be described with reference to the drawings. FIG. 10 is a cross-sectional view schematically showing a light-emitting device 200 according to the first modification example of the present embodiment.

[0056] Hereinafter, in the light-emitting device 200 according to the first modification example of the present embodiment, members having the same functions as those of the members of the light-emitting device 100 according to the above-described present embodiment are denoted by the same reference numerals, and detailed descriptions thereof are omitted. This also applies to the light-emitting device according to the second modification example of the present embodiment described later.

[0057] The light-emitting device 200 is different from the above-described light-emitting device 100 in that it includes an optical element 80 as shown in FIG. 10.

[0058] The optical element 80 is provided on the first semiconductor layer 50. The optical element 80 is provided on the side of the first semiconductor layer 50 opposite to the driving substrate 10. The first semiconductor layer 50 is provided between the plurality of columnar portions 30 and the optical element 80.

[0059] A plurality of optical elements 80 are provided corresponding to the plurality of pixel electrodes 20. The optical element 80 overlaps the pixel electrode 20 in plan view. Among the plurality of optical elements 80, the first optical element 80a overlaps the first pixel electrode 20a. Among the plurality of optical elements 80, the second optical element 80b overlaps the second pixel electrode 20b.

[0060] The optical element 80, for example, condenses the light generated in the quantum well layer 34. The optical element 80 may be a condenser lens. The optical element 80 may be a collimator lens. The plurality of optical elements 80 may constitute a microlens array.

[0061] In the light-emitting device 200, a first optical element 80a provided on the side opposite to the driving substrate 10 of the first semiconductor layer 50 and overlapping the first pixel electrode 20a in plan view, and a second optical element provided on the side opposite to the driving substrate 10 of the first semiconductor layer 50 and overlapping the second pixel electrode 20b in plan view. Element 80b. Therefore, in the light-emitting device 200, the light generated in the quantum well layer 34 of the first columnar portion 30a can be adjusted to a desired light distribution by the first optical element 80a. Further, the light generated in the quantum well layer 34 of the second columnar portion 30b can be adjusted to a desired light distribution by the second optical element 80b.

[0062] 3.2. Second modification Next, a light-emitting device according to a second modification of the present embodiment will be described with reference to the drawings. FIG. 11 is a cross-sectional view schematically showing a light-emitting device 300 according to a second modification of the present embodiment. FIG. 12 is a plan view schematically showing the light-emitting device 300 according to the second modification of the present embodiment. Note that FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 12.

[0063] In the light-emitting device 300, as shown in FIGS. 11 and 12, the shape of the common electrode 60 is different from that of the light-emitting device 100 described above. In the light-emitting device 300, the common electrode 60 has a frame portion 62 and an extending portion 64.

[0064] As shown in FIG. 12, the frame portion 62 surrounds the pixel electrode 20 in plan view. The frame portion 62 has a first portion 62a, a second portion 62b, a third portion 62c, and a fourth portion 62d. In plan view, the first portion 62a and the second portion 62b are arranged in the first direction. In plan view, a plurality of pixel electrodes 20 are provided between the first portion 62a and the second portion 62b. In plan view, the third portion 62c and the fourth portion 62d are arranged in a second direction orthogonal to the first direction. In plan view, a plurality of pixel electrodes 20 are provided between the third portion 62c and the fourth portion 62d.

[0065] The extending portion 64 is connected to the frame portion 62. The extending portion 64 extends between adjacent pixel electrodes 20. For example, a plurality of extending portions 64 are provided. The first extending portion 64a among the plurality of extending portions 64 extends from the first portion 62a to the second portion 62b. In the illustrated example, two first extending portions 64a are provided. One of the two first extending portions 64a is provided between the first pixel electrode 20a and the second pixel electrode 20b in plan view. The second extending portion 64b among the plurality of extending portions 64 extends from the third portion 62c to the fourth portion 62d. In the illustrated example, two first extending portions 64a are provided.

[0066] In the light-emitting device 300, the common electrode 60 has, in plan view, a frame portion 62 surrounding the first pixel electrode 20a and the second pixel electrode 20b, and an extending portion 64 extending between the first pixel electrode 20a and the second pixel electrode 20b. Therefore, in the light-emitting device 300, compared with the case where the extending portion 64 is not provided, the distance through which the current of the first semiconductor layer 50 having a relatively high sheet resistance flows can be shortened, and the voltage drop in the first semiconductor layer 50 can be suppressed. This is particularly effective when the first semiconductor layer 50 is thin or when the area of the light-emitting device is large.

[0067] 4. Projector Next, a projector as an electronic device according to the present embodiment will be described with reference to the drawings. FIG. 13 is a diagram schematically showing a projector 700 according to the present embodiment.

[0068] The projector 700 has, for example, a light emitting device 100 as a light source.

[0069] The projector 700 includes a housing (not shown) and a red light source 100R, a green light source 100G, and a blue light source 100B that are provided inside the housing and emit red light, green light, and blue light, respectively. For convenience, in FIG. 13, the red light source 100R, the green light source 100G, and the blue light source 100B are shown in a simplified manner.

[0070] The projector 700 further includes, for example, a first optical element 702R, a second optical element 702G, a third optical element 702B, a first light modulation device 704R, a second light modulation device 704G, a third light modulation device 704B, and a projection device 708 that are provided inside the housing. The first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B are, for example, transmissive liquid crystal light valves. The projection device 708 is, for example, a projection lens.

[0071] The light emitted from the red light source 100R enters the first optical element 702R. The light emitted from the red light source 100R is condensed by the first optical element 702R. Note that the first optical element 702R may have functions other than condensing light. The second optical element 702G and the third optical element 702B may also have functions other than condensing light.

[0072] The light condensed by the first optical element 702R enters the first light modulation device 704R. The first light modulation device 704R modulates the incident light according to image information. Then, the projection device 708 enlarges the image formed by the first light modulation device 704R and projects it onto the screen 710.

[0073] The light emitted from the green light source 100G is incident on the second optical element 702G. The light emitted from the green light source 100G is condensed by the second optical element 702G.

[0074] The light condensed by the second optical element 702G is incident on the second light modulation device 704G. The second light modulation device 704G modulates the incident light according to the image information. Then, the projection device 708 enlarges the image formed by the second light modulation device 704G and projects it onto the screen 710.

[0075] The light emitted from the blue light source 100B is incident on the third optical element 702B. The light emitted from the blue light source 100B is condensed by the third optical element 702B.

[0076] The light condensed by the third optical element 702B is incident on the third light modulation device 704B. The third light modulation device 704B modulates the incident light according to the image information. Then, the projection device 708 enlarges the image formed by the third light modulation device 704B and projects it onto the screen 710.

[0077] The projector 700 further has, for example, a cross-dichroic prism 706 that synthesizes the light emitted from the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B and guides it to the projection device 708.

[0078] The three color lights modulated by the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B are incident on the cross-dichroic prism 706. The cross-dichroic prism 706 is formed by bonding four right-angled prisms, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are arranged on its inner surface. These dielectric multilayer films synthesize the three color lights to form light representing a color image. Then, the synthesized light is projected onto the screen 710 by the projection device 708, and an enlarged image is displayed.

[0079] Note that the red light source 100R, the green light source 100G, and the blue light source 100B control the light emitting device 1 00 as pixels of the video according to the image information, and directly form the video without using the first light modulation device 704R, the second light modulation device 704G, and the third light modulation device 704B. Then, the projection device 708 may project the video formed by the red light source 100R, the green light source 100G, and the blue light source 100B onto the screen 710 after enlarging it.

[0080] In the above example, a transmissive liquid crystal light valve is used as the light modulation device, but a light valve other than liquid crystal may be used, or a reflective light valve may be used. Examples of such light valves include a reflective liquid crystal light valve and a digital micro mirror device (Digital Micro Mirror Device). The configuration of the projection device is appropriately changed according to the type of the light valve used.

[0081] Further, the light source can also be applied to a light source device of a scanning type image display device having scanning means which is an image forming device for displaying an image of a desired size on a display surface by scanning light from the light source on the screen.

[0082] 5. Display Next, a display as an electronic device according to the present embodiment will be described with reference to the drawings. FIG. 14 is a plan view schematically showing the display 800 according to the present embodiment. FIG. 15 is a cross-sectional view schematically showing the display 800 according to the present embodiment. In FIG. 14, the X-axis and the Y-axis are illustrated as two axes orthogonal to each other. For the sake of convenience, in FIGS. 14 and 15, the light emitting device 100 is illustrated in a simplified manner.

[0083] The display 800 has, for example, a light emitting device 100 as a light source.

[0084] The display 800 is a display device that displays images. The images include those that display only character information. The display 800 is a self-emitting display. As shown in FIGS. 14 and 15, the display 800 has, for example, a drive circuit 810, a lens array 820, and a heat sink 830.

[0085] The drive circuit 810 is provided on the drive substrate 10. The drive circuit 810 drives the light-emitting element 102, for example, based on the input image information. The drive substrate 10 has, for example, a display area 812. The drive circuit 810 has a data line drive circuit 814, a scan line drive circuit 816, and a control circuit 818.

[0086] The display area 812 is composed of a plurality of pixels P. In the illustrated example, the pixels P are arranged along the X-axis and the Y-axis.

[0087] Although not shown, the drive substrate 10 is provided with a plurality of scan lines and a plurality of data lines. For example, the scan lines extend along the X-axis, and the data lines extend along the Y-axis. The scan lines are connected to the scan line drive circuit 816. The data lines are connected to the data line drive circuit 814. The pixel P is provided corresponding to the intersection of the scan line and the data line.

[0088] One pixel P has, for example, one light-emitting element 102, one optical element 80, and a pixel circuit (not shown). The pixel circuit has a switching transistor that functions as a switch of the pixel P. The gate of the switching transistor is connected to the scan line, and one of the source or drain is connected to the data line.

[0089] The data line drive circuit 814 and the scan line drive circuit 816 are circuits that control the driving of the light-emitting element 102 constituting the pixel P. The control circuit 818 controls the display of the image.

[0090] The control circuit 818 is supplied with image data from an upper circuit. The control circuit 818 supplies various signals based on the image data to the data line driving circuit 814 and the scanning line driving circuit 816.

[0091] When the scanning line driving circuit 816 activates the scanning signal and the scanning line is selected, the switching transistor of the selected pixel P is turned on. At this time, the data line driving circuit 814 supplies a data signal from the data line to the selected pixel P, so that the light-emitting element 102 of the selected pixel P emits light according to the data signal.

[0092] The lens array 820 is composed of a plurality of lenses 822. The heat sink 830 is in contact with the driving substrate 10. The material of the heat sink 830 is, for example, a metal such as copper or aluminum. The heat sink 830 dissipates the heat generated by the light-emitting element 102.

[0093] 6. Head-Mounted Display 6.1. Overall Configuration Next, the head-mounted display as the electronic device according to the present embodiment will be described with reference to the drawings. FIG. 16 is a perspective view schematically showing the head-mounted display 900 according to the present embodiment.

[0094] As shown in FIG. 16, the head-mounted display 900 is a head-mounted display having an appearance like glasses. The head-mounted display 900 is worn on the head of an observer. The observer is a user who uses the head-mounted display 900. The head-mounted display 900 can allow the observer to visually recognize video light by a virtual image and can also allow the observer to visually recognize the outside world image in a see-through manner.

[0095] The head-mounted display 900 has, for example, a first display unit 910a, a second display unit 910b, a frame 920, a first temple 930a, and a second temple 930b.

[0096] The first display unit 910a and the second display unit 910b display images. Specifically, the first display unit 910a displays a virtual image for the right eye of the observer. The second display unit 910b displays a virtual image for the left eye of the observer. The display units 910a and 910b have, for example, an image forming device 911 and a light guiding device 915.

[0097] The image forming device 911 forms image light. The image forming device 911 has, for example, an optical system such as a light source and a projection device, and an external member 912. The external member 912 houses the light source and the projection device.

[0098] The light guiding device 915 covers in front of the observer's eyes. The light guiding device 915 guides the video light formed by the image forming device 911, and causes the observer to visually recognize the external light and the video light overlapping each other. Details of the image forming device 911 and the light guiding device 915 will be described later.

[0099] The frame 920 supports the first display unit 910a and the second display unit 910b. The frame 920 surrounds the display units 910a and 910b, for example. In the illustrated example, the image forming device 911 of the first display unit 910a is attached to one end of the frame 920. The image forming device 911 of the second display unit 910b is attached to the other end of the frame 920.

[0100] The first temple 930a and the second temple 930b extend from the frame 920. In the illustrated example, the first temple 930a extends from one end of the frame 920. The second temple 930b extends from the other end of the frame 920.

[0101] The first temple 930a and the second temple 930b are suspended on the ears of the observer when the head-mounted display 900 is worn by the observer. The head of the observer is positioned between the temples 930a and 930b.

[0102] 6.2. Image Forming Device and Light Guiding Device FIG. 17 is a diagram schematically showing an image forming device 911 and a light guiding device 915 of a first display unit 910a of the head-mounted display 900. Note that the first display unit 910a and the second display unit 910b basically have the same configuration. Therefore, the following description of the first display unit 910a is applicable to the second display unit 910b.

[0103] As shown in FIG. 17, the image forming device 911 includes, for example, a light emitting device 100 as a light source, a light modulation device 913, and a projection device 914 for imaging.

[0104] The light modulation device 913 modulates the light incident from the light emitting device 100 according to image information and emits image light. The light modulation device 913 is a transmissive liquid crystal light valve. Note that the light emitting device 100 may be a self-luminous light emitting device that emits light according to the input image information. In this case, the light modulation device 913 is not provided.

[0105] The projection device 914 projects the image light emitted from the light modulation device 913 toward the light guiding device 915. The projection device 914 is, for example, a projection lens. As the lens constituting the projection device 914, a lens having an axisymmetric plane as a lens surface may be used.

[0106] The light guiding device 915 is accurately positioned with respect to the projection device 914, for example, by being screwed to the lens barrel of the projection device 914. The light guiding device 915 includes, for example, an image light guiding member 916 that guides image light and a transparent member 918 for perspective viewing.

[0107] The image light guide light member 916 receives the image light emitted from the projection device 914. The image light guide light member 916 is a prism that guides the image light toward the observer's eyes. The image light incident on the image light guide light member 916 is repeatedly reflected on the inner surface of the image light guide light member 916 and then reflected by the reflection layer 917 and emitted from the image light guide light member 916. The image light emitted from the image light guide light member 916 reaches the observer's eyes. The reflection layer 917 is composed of, for example, a metal or a dielectric multilayer film. The reflection layer 917 may be a half mirror.

[0108] The transparent member 918 is adjacent to the image light guide light member 916. The transparent member 918 is fixed to the image light guide light member 916. The outer surface of the transparent member 918 is continuous with, for example, the outer surface of the image light guide light member 916. The transparent member 918 allows the observer to see the external light through it. The image light guide light member 916 also has a function of allowing the observer to see the external light through it in addition to the function of guiding the image light. Note that the head-mounted display 900 may be configured not to allow the observer to see the external light through it.

[0109] The light-emitting device according to the above-described embodiment can be used in addition to projectors, displays, and head-mounted displays. The light-emitting device according to the above-described embodiment is used, for example, in indoor and outdoor lighting, laser printers, scanners, sensing devices using light, EVF (Electronic View Finder), wearable displays such as smartwatches, vehicle-mounted lights, and vehicle-mounted head-up displays.

[0110] The above-described embodiments and modifications are merely examples and are not limited thereto. For example, it is also possible to appropriately combine each embodiment and each modification.

[0111] The present invention includes a configuration that is substantially the same as the configuration described in the embodiments, for example, a configuration having the same functions, methods, and results, or a configuration having the same objectives and effects. The present invention also includes a configuration in which a non-essential part of the configuration described in the embodiments is replaced. The present invention also includes a configuration that exhibits the same operational effects as the configuration described in the embodiments or a configuration that can achieve the same objective. The present invention also includes a configuration in which a known technique is added to the configuration described in the embodiments.

[0112] The following content is derived from the above-described embodiments and modified examples.

[0113] One aspect of the light-emitting device is a substrate, a plurality of columnar portions, a first semiconductor layer of a first conductivity type provided so as to overlap the plurality of columnar portions, a first pixel electrode provided between a plurality of first columnar portions among the plurality of columnar portions and the substrate, a second pixel electrode provided between a plurality of second columnar portions among the plurality of columnar portions and the substrate and spaced apart from the first pixel electrode, a common electrode provided on the side opposite to the substrate of the first semiconductor layer, and includes each of the plurality of columnar portions has a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type provided between the first semiconductor layer and the second semiconductor layer, and a quantum well layer provided between the second semiconductor layer and the third semiconductor layer. has.

[0114] According to this light-emitting device, the distance between the first pixel electrode and the second pixel electrode can be reduced.

[0115] In one aspect of the light-emitting device, the common electrode may not overlap the first pixel electrode and the second pixel electrode in a plan view.

[0116] According to this light emitting device, the possibility that the light generated in the quantum well layer is absorbed by the common electrode can be reduced.

[0117] In one embodiment of the light emitting device, The common electrode, in a plan view, a frame portion surrounding the first pixel electrode and the second pixel electrode; an extension portion provided between the first pixel electrode and the second pixel electrode; may have the following structure:

[0118] According to this light emitting device, the distance over which a current flows in the first semiconductor layer, which has a relatively high sheet resistance, can be shortened, and the voltage drop in the first semiconductor layer can be suppressed.

[0119] In one embodiment of the light emitting device, The first semiconductor layer is provided on the opposite side to the substrate, and the first pixel electrode is disposed on the opposite side to the substrate. a first optical element overlapping the pole; a second optical element provided on the opposite side of the first semiconductor layer from the substrate and overlapping the second pixel electrode in a plan view; may include:

[0120] According to this light emitting device, the first optical element can adjust the light generated in the quantum well layer of the first columnar section to a desired light distribution, and the second optical element can adjust the light generated in the quantum well layer of the second columnar section to a desired light distribution.

[0121] In one embodiment of the light emitting device, The first pixel electrode and the second pixel electrode may be made of a metal.

[0122] In this light emitting device, the first pixel electrode can reflect light generated in the quantum well layer of the first columnar section, and the second pixel electrode can reflect light generated in the quantum well layer of the second columnar section.

[0123] In one embodiment of the light emitting device, Among the plurality of columnar portions, the third columnar portion may be provided between the first pixel electrode and the second pixel electrode in a plan view.

[0124] According to this light-emitting device, since the third columnar portion provided between the first pixel electrode and the second pixel electrode in a plan view is not removed, the structure of the light-emitting device can be simplified.

[0125] One aspect of the electronic device has one aspect of the light-emitting device.

[0126] One aspect of the method for manufacturing a light-emitting device includes a step of forming a first semiconductor layer of a first conductivity type on a first substrate; a step of forming a plurality of columnar portions on the first semiconductor layer; a step of forming a first pixel electrode over a plurality of first columnar portions among the plurality of columnar portions and forming a second pixel electrode over a plurality of second columnar portions among the plurality of columnar portions; a step of bonding a structure including the first substrate, the first semiconductor layer, the plurality of columnar portions, the first pixel electrode, and the second pixel electrode to a second substrate with the first pixel electrode side and the second pixel electrode side facing the second substrate; a step of removing the first substrate to expose the first semiconductor layer; a step of forming a common electrode on the first semiconductor layer; and in the step of forming the plurality of columnar portions, the plurality of columnar portions having a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type, and a quantum well layer provided between the second semiconductor layer and the third semiconductor layer are formed.

[0127] According to this method for manufacturing a light-emitting device, a light-emitting device in which the distance between the first pixel electrode and the second pixel electrode can be reduced can be manufactured.

Description of Reference Numerals

[0128] 10… Driving substrate, 12… Pad electrode, 20… Pixel electrode, 20a… First pixel electrode, 20b… Second pixel electrode, 30… Columnar part, 30a… First columnar part, 30b… Second columnar part, 30c… Third columnar part, 32… Second semiconductor layer, 34… Quantum well layer, 36… Third semiconductor layer, 40… Mask layer, 42… Opening, 50… First semiconductor layer, 60… Common electrode, 62… Frame part, 62a… First part , 62b… Second part, 62c… Third part, 62d… Fourth part, 64… Extension part, 64a… First extension part, 64b… Second extension part, 70… Growth substrate, 80… Optical element, 80a… First optical element, 80b… Second optical element, 100… Light-emitting device, 100R… Red light source, 100G… Green light source, 100B… Blue light source, 102… Light-emitting element, 110… Structure, 200, 300… Light-emitting devices, 700… Projector, 702R… First optical element, 702G… Second optical element, 702B… Third optical element, 704R… First light modulation device, 704G… Second light modulation device, 704B… Third light modulation device, 706… Cross-dichroic prism, 708… Projection device, 710… Screen, 800… Display, 810… Driving circuit, 812… Display area, 814… Data line driving circuit, 816… Scanning line driving circuit, 818… Control circuit, 820… Lens array, 822… Lens, 830… Heat sink, 900… Head-mounted display, 910a… First display part, 910b… Second display part, 911… Image forming device, 912… External member, 913… Light modulation device, 914… Projection device, 915… Light guide device, 916… Video light guide member, 917… Reflective layer, 918… Transparent member, 920… Frame, 930a… First template, 930b… Second template

Claims

1. A substrate, a plurality of columnar portions, a first semiconductor layer of a first conductivity type provided so as to overlap with the plurality of columnar portions, a first pixel electrode provided between a plurality of first columnar portions among the plurality of columnar portions and the substrate, a second pixel electrode provided between a plurality of second columnar portions among the plurality of columnar portions and the substrate and spaced apart from the first pixel electrode, a common electrode provided on the side of the first semiconductor layer opposite to the substrate, comprising, each of the plurality of columnar portions, a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type provided between the first semiconductor layer and the second semiconductor layer, a quantum well layer provided between the second semiconductor layer and the third semiconductor layer, a light-emitting device having the above.

2. In claim 1, the common electrode does not overlap with the first pixel electrode and the second pixel electrode in plan view, a light-emitting device.

3. In claim 2, the common electrode, in plan view, a frame portion surrounding the first pixel electrode and the second pixel electrode, an extending portion provided between the first pixel electrode and the second pixel electrode, a light-emitting device having the above.

4. In claim 1, a first optical element provided on the side of the first semiconductor layer opposite to the substrate and overlapping with the first pixel electrode in plan view, a second optical element provided on the side of the first semiconductor layer opposite to the substrate and overlapping with the second pixel electrode in plan view, a light-emitting device including the above.

5. In claim 1, the materials of the first pixel electrode and the second pixel electrode are metals, a light-emitting device.

6. In claim 1, a third columnar portion among the plurality of columnar portions is provided between the first pixel electrode and the second pixel electrode in plan view, a light-emitting device.

7. An electronic device including the light-emitting device according to any one of claims 1 to 6.

8. A step of forming a first semiconductor layer of a first conductivity type on a first substrate, a step of forming a plurality of columnar portions on the first semiconductor layer, a step of forming a first pixel electrode over a plurality of first columnar portions among the plurality of columnar portions and forming a second pixel electrode over a plurality of second columnar portions among the plurality of columnar portions, A step of bonding a structure having the first substrate, the first semiconductor layer, the plurality of columnar portions, the first pixel electrode, and the second pixel electrode to a second substrate with the first pixel electrode and the second pixel electrode sides facing the second substrate toward the second substrate. A step of removing the first substrate to expose the first semiconductor layer; A step of forming a common electrode on the first semiconductor layer; comprising; In the step of forming the plurality of columnar portions, A method of manufacturing a light-emitting device, which forms the plurality of columnar portions having a second semiconductor layer of a second conductivity type different from the first conductivity type, a third semiconductor layer of the first conductivity type, and a quantum well layer provided between the second semiconductor layer and the third semiconductor layer.

Images