JP4670151B2 - Surface-emitting light-emitting device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nitride semiconductor (In_XAl_YGa_1-XYMore particularly, the present invention relates to a nitride semiconductor light-emitting device that can be used as a micro light source. The surface-emitting light-emitting device has a semiconductor layer made of N, 0 ≦ X, 0 ≦ Y, and X + Y ≦ 1.
[0002]
[Prior art]
The present applicant has put blue and green nitride semiconductor light emitting diodes having high light emission output into practical use as light sources for large displays and the like. For example, in Japanese Patent Laid-Open No. 9-153642, a buffer layer made of GaN, a Si-doped n-type GaN layer, a light-emitting layer made of undoped InGaN, an Mg-doped p-type AlGaN layer, an Mg-doped layer, A light emitting diode consisting of a p-type GaN layer is described.
[0003]
However, the light-emitting diodes used in such large-sized displays are not sufficiently satisfactory when they are used as light sources for optical fiber communication or electrophotography, or as micro light sources such as virtual reality. .
[0004]
Therefore, as a practical micro light source, an edge-emitting light emitting diode can be cited. An edge-emitting light-emitting element having a semiconductor layer made of a general nitride semiconductor has the same basic element structure as a semiconductor laser, and a double hetero structure in which the light-emitting layer is sandwiched between wide-bandgap p-type and n-type semiconductor layers. In a nitride semiconductor edge emitting light emitting diode, an AlGaN / GaN / InGaN separate confinement heterostructure (SCH) is used. Furthermore, since the light emitting layer is formed in a stripe shape and has a structure in which light is emitted from the light emitting layer exposed on the end face, the condensed spot size is smaller than the light emitting diode for a large display as described above. Luminescence can be obtained.
[0005]
[Problems to be solved by the invention]
However, although the edge-emitting light emitting diode as described above can obtain light with a small spot size, not only the end face of the light emitting layer but also the end face of the n-type semiconductor layer stacked on the substrate side of the light emitting layer. However, since light is emitted, there is a problem that multi-mode light emission occurs and it is difficult to obtain a near-field pattern as a sufficiently good single spot. For this reason, the conventional edge-emitting light-emitting diode cannot be sufficiently satisfied as a minute light source. In addition, it is difficult to sufficiently extract light emitted in the back direction away from the emission end face.
[0006]
Accordingly, the present invention provides a surface-emitting light-emitting element that extracts light with a small spot size from the semiconductor stack side, not from the end face, as a micro light source used for optical fiber communication or electrophotographic light sources or virtual reality. The purpose is to do.
[0007]
[Means for Solving the Problems]
A surface-emitting light emitting device according to an embodiment includes a substrate, a semiconductor layer sequentially having an n-type nitride semiconductor layer, a light-emitting layer, and a p-type nitride semiconductor layer on the substrate, and an n-type nitride semiconductor in the semiconductor layer. A cavity covered with a layer, a light emitting layer and a p-type nitride semiconductor layer, and a region corresponding to the cavity as viewed from the p-type nitride semiconductor layer side as an opening, and the opening on the p-type semiconductor layer And a p-electrode provided around the light-emitting layer, and the light from the light-emitting layer is reflected by the cavity to the p-type nitride semiconductor layer side and can be extracted to the outside through the opening. And
  A surface-emitting light-emitting device according to another embodiment is a surface-emitting light-emitting device including a semiconductor layer including at least an n-type nitride semiconductor layer, a light-emitting layer, and a p-type nitride semiconductor layer, wherein the semiconductor layer includes: The cavity has at least a cavity penetrating from the light emitting layer to the n-type nitride semiconductor layer, and the outer wall of the cavity has an inversely tapered shape.
[0008]
Thus, by providing a refractive index difference between the semiconductor layer and the air layer in the cavity in the semiconductor layer, and by forming the outer wall of the cavity, which is an interface between them, into an inversely tapered shape, Is efficiently condensed on the interface, and the condensed light can be extracted upward in a single mode. Since the spot shape of the light corresponds to the bottom surface of the cavity, it is possible to easily obtain a round spot that has been difficult until now by adjusting the bottom surface of the cavity.
Further, according to the present invention, since the light emitted from the light emitting layer around the cavity propagates in the thickness direction of the p-type nitride semiconductor layer and is extracted outside, the surface light emitting device according to the present invention In comparison, the optical waveguide path can be made extremely short, and single-mode light emission can be achieved with high output.
[0009]
In addition, the p-type nitride semiconductor layer has a positive electrode around the opening with a light emitting surface positioned above the cavity as an opening on the uppermost surface.
When the positive electrode is formed so as to surround the light emitting surface in this way, current can be concentrated on the light emitting surface, and uniform light emission can be obtained. Further, the output can be easily improved by adjusting the area of the positive electrode.
[0010]
In addition, by having an opaque film with at least the light emitting surface as an opening on the upper surface of the p-type nitride semiconductor layer and the side surface of the semiconductor layer, the light from other than the light emitting surface is blocked to correspond to the shape of the cavity. Only the emitted light can be extracted with high brightness from the upper surface direction.
[0011]
Further, a negative electrode is provided on the n-type nitride semiconductor layer partially exposed by etching from the p-type nitride semiconductor layer side, and is continuously in contact with the etching surface between at least the positive electrode and the negative electrode. It has an insulating film. This can suppress a short circuit between the electrodes.
[0012]
A method for manufacturing a surface-emitting light-emitting device according to the present invention is a method for manufacturing a surface-emitting light-emitting device comprising a semiconductor layer having at least an n-type nitride semiconductor layer, a light-emitting layer, and a p-type nitride semiconductor layer, It has a 1st process of providing a mask layer in a part on a board | substrate, and a 2nd process of laminating | stacking the said semiconductor layer in order on the said board | substrate after the said 1st process.
[0013]
By manufacturing in this way, a cavity having the mask layer as a bottom surface is formed in the semiconductor layer, and a spot micropoint light source corresponding to the shape of the mask layer can be obtained. It is preferable to provide a substantially circular spot when a mask layer having a circular upper surface is provided.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, surface-emitting light-emitting elements according to embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view of a surface light emitting element according to the present embodiment, and FIG. 2 is a schematic cross-sectional view taken along the line AA ′ of FIG.
As shown in FIG. 2, the surface-emitting light-emitting device of the present embodiment has a mask layer and an n-type nitride semiconductor layer having a thickness larger than that of the mask layer provided on a substrate separately from each other. A light emitting layer and a p-type nitride semiconductor layer are sequentially stacked on the n-type nitride semiconductor layer. On the mask layer is a cavity where no semiconductor layer is stacked. A negative electrode is provided on the surface of the n-type nitride semiconductor layer exposed by etching from the p-type nitride semiconductor layer side of the laminated semiconductor layer, and the p-type nitride is located above the cavity. A positive electrode is provided around the surface of the physical semiconductor layer as an opening.
[0015]
Hereinafter, a detailed configuration and manufacturing method of the surface-emitting light-emitting element according to the embodiment will be described.
[0016]
[First step]
First, the mask layer 2 is provided on a part of the substrate 1.
(Substrate 1)
The substrate 1 is preferably made of a material having a refractive index smaller by 0.2 or more than the semiconductor layer stacked on the substrate. This is because the amount of light entering the substrate from the semiconductor layer formed on the substrate can be reduced. As a substrate, sapphire whose main surface is a sapphire C-plane, R-plane or A-plane, or other spinel (MgA1₂O_FourIn addition to an insulating substrate such as SiC), a semiconductor substrate such as SiC (including 6H, 4H, and 3C), Si, ZnO, GaAs, and GaN can be used. Sapphire is particularly preferable as the substrate because the crystallinity of the nitride semiconductor layer formed thereon can be improved. In the case of using a heterogeneous substrate, after growing the nitride semiconductor substrate, the heterogeneous substrate may be removed by a method such as polishing to form an element structure as a single substrate of the nitride semiconductor, The heterogeneous substrate may be removed after the element structure is formed.
[0017]
(Mask layer 2)
The material of the mask layer 2 is not particularly limited as long as it is not decomposed at a high temperature and a semiconductor layer is not formed on the surface. Specifically, SiO₂, SiN, W and the like are preferable. By providing a semiconductor layer after providing such a mask layer, a cavity that is an air layer can be formed on the upper surface of the mask layer. By adopting such a configuration, light can be almost totally reflected at the interface using the difference in refractive index between the air layer and the semiconductor layer and extracted upward.
[0018]
The mask layer is preferably provided in a columnar shape. As a result, it is possible to obtain a spot light having a perfect circular shape, which is not possible with edge emission. The diameter of the bottom surface of the mask layer corresponds to the spot diameter of the emitted light, and light having a required spot diameter can be easily emitted by adjusting the diameter of the mask layer in the first step. In order to obtain good single mode light, the diameter of the mask layer is 0.5 μm to 20 μm, more preferably 1 μm to 10 μm.
The thickness of the mask layer is preferably 2.5% to 12.5% of the thickness of the n-type nitride semiconductor layer to be stacked later. After providing the mask layer with such a thickness, the semiconductor layers are sequentially stacked, and a cavity penetrating from the n-type nitride semiconductor layer to the p-type nitride semiconductor layer can be easily formed. The light reflecting surface can be enlarged.
[0019]
[Second step]
A semiconductor layer is sequentially stacked over a substrate having a mask layer.
(Semiconductor layers 3, 4, 5)
In the surface light emitting element of the present invention, at least an n-type nitride semiconductor layer 3, a light emitting layer 4, and a p-type nitride semiconductor layer 5 are sequentially stacked. For example, an n-type nitride semiconductor layer made of GaN doped with Si on a substrate, a light emitting layer made of InGaN, a p-type cladding layer made of AlGaN doped with Mg, and a p-type contact made of GaN doped with Mg The thing of the double hetero structure by which the layer was laminated | stacked in order is mentioned. The p-type cladding layer can be omitted. Further, a clad layer made of p-type and n-type AlGaN may be formed with a thickness of 50 nm or less, more preferably 40 nm or less. The light emitting layer 103 can also be configured as a single quantum well structure or a multiple quantum well structure.
[0020]
(Cavity 13)
In the present invention, by laminating the semiconductor layer on the substrate having the mask layer, the semiconductor layer has at least a hollow portion penetrating from the light emitting layer to the n-type nitride semiconductor layer, and the outer wall of the hollow portion is Inverted taper shape. In this way, by providing a cavity portion that is an air layer in the semiconductor layer, light emitted at a high current density is efficiently collected and totally reflected on the outer wall of the cavity portion so that light of a desired spot size can be output with high power. Thus, it can be emitted upward. In addition to providing a mask layer on the substrate, such a cavity can be formed by a method of laminating semiconductor layers after roughening the substrate corresponding to the bottom surface of the cavity to be formed.
[0021]
The position occupied by the cavity in the semiconductor layer is not particularly limited, but the cavity is preferably provided over the entire semiconductor layer. This is preferable because all the light emitted from each semiconductor layer can be condensed on the outer wall of the cavity. Moreover, it is preferable that an outer wall is made into the reverse taper shape inclined toward the center of a cavity part. Thereby, the light condensed on the outer wall can be efficiently totally reflected and extracted upward. Further, in the cross-sectional view of the cavity cut perpendicularly to the direction of the semiconductor lamination, the tips of the left and right outer walls intersect at one point to form one corner, that is, the cavity that is substantially triangular due to the bottom of the cavity and the outer wall. When the is formed, the light of the spot having the bottom shape of the cavity can be emitted with high luminance without causing color unevenness.
[0022]
(Electrodes 6, 7)
Further, in the present invention, the positive electrode 6 and the negative electrode 7 are not particularly limited as long as they are materials that can make ohmic contact with the respective underlayers, and various materials can be used. . Specific examples of the electrode include those described in Examples described later. The positive electrode is formed so as to surround the light emitting surface with the light emitting surface above the cavity on the p-type contact layer as an opening, and the negative electrode is exposed by etching so as to surround the positive electrode. Preferably, the n-type contact layer is formed on almost the entire surface. As a result, current can be injected concentratedly on the light emitting surface, and light emitted at a high current density can be efficiently condensed in the optical waveguide hole, so that the light emission output of the device can be increased. Further, the contrast of light is improved by providing the negative electrode on almost the entire surface of the exposed n-type contact layer.
[0023]
In the present invention, the means for etching the nitride semiconductor layer is preferably performed by dry etching, for example, a method such as RIE (reactive ion etching).
[0024]
(Insulating film 8)
In the present invention, after forming the positive electrode and the negative electrode, the insulating film 8 is provided so as to cover at least the semiconductor layer between the respective electrodes by using the light emitting surface located above the bonding portion and the cavity of each electrode as an opening. Just do it. In the present embodiment, an insulating film is continuously formed on the element surface and the end face exposed by etching, except for the light emitting surface, the positive electrode, and the pad electrode forming portion of the negative electrode. Accordingly, it is possible to prevent a short circuit between the respective electrodes, and it is preferable to use a film having reflectivity because it is possible to suppress light leakage from the upper surface and the side surface. The insulating film is preferably provided so as to slightly cover the upper surface of each electrode. With such a configuration, peeling between each electrode and the base layer can be suppressed. Here, the insulating film is not particularly limited as long as it is an electrically insulating material. For example, ZrO₂, SiO₂, SiN, Al₂O_Three, AlN, Ta₂O_Five, Nb₂O_Five, HfO₂TiO₂Etc., and the film thickness thereof is preferably set in the range of 50 to 5000 mm.
[0025]
(Pad electrodes 9, 10)
In addition, it is preferable that the p-pad electrode 9 is continuously formed on one surface so as to cover the positive electrode on the p-type nitride semiconductor layer because bonding can be performed satisfactorily and the heat dissipation of the element is improved. Further, the n pad electrode 10 may be formed on a part of the negative electrode. These pad electrodes are not particularly limited as long as they have good adhesion to the electrodes which are the wire and the underlying layer. Next, the first layer / third layer two-layer structure selected from the materials, or the first A three-layer structure of layer / second layer / third layer is preferable.
First layer: at least one selected from Ni, Cu, Rh, Ru
Second layer: at least one selected from Ti, W, Pt, Ta, Mo,
Third layer: Au.
More preferably, Ni / Ti / Au, Ni / Au, Cu / Pt / Au, Ni / Pt / Au, and the film thickness is set to 1000 to 3 μm. Further, a metallized layer 11 is formed on almost the entire top surface of the p-type nitride semiconductor layer so as to cover the p-bad electrode.
[0026]
(Impermeable film 12)
If an opaque film is provided on the upper surface of the p-type nitride semiconductor layer and the side surface of the semiconductor layer with the light emitting surface at least above the cavity as an opening, the unevenness of light emission can be suppressed. A minute point light source can be obtained in a single mode only from the light emitting surface. The light-impermeable film can be used as long as it does not transmit light, but is preferably composed of a metal such as Rh, RhO, Ni, Cr, RuO, or Cu or a metal oxide thereof. Can do. The metal may be formed directly on the semiconductor layer as long as it is in contact with the semiconductor layer and the Schottky barrier, or any metal may be formed as long as it is formed through an insulating film. Furthermore, it is particularly preferable to form a dielectric multilayer film and further form a metal thin film thereon. In the present invention, a multilayer film such as Ni / Au is used for the non-light-transmitting film continuously provided on the p-type nitride semiconductor layer and on the etching surface so as to cover the positive electrode. And preferred. Examples of the method for forming the opaque film include sputtering and vapor deposition.
[0027]
【Example】
Examples according to the present invention will be described below. In addition, this invention is not limited to a following example.
[Example 1]
(Mask layer 2)
On the substrate 1 made of sapphire (C-plane), SiO₂A mask layer having a cylindrical shape with a diameter of 4 μm and a height of 0.5 μm is formed, and the surface is cleaned in a reaction vessel at 1050 ° C. in a hydrogen atmosphere.
[0028]
(Buffer layer)
Subsequently, the substrate temperature is lowered to 510 ° C., hydrogen is used as the carrier gas, TMG (trimethylgallium) gas and ammonia gas are used as the source gas, and a buffer layer made of GaN is grown on the substrate to a thickness of about 200 angstroms ( Not shown).
[0029]
(N-type nitride semiconductor layer 3)
Subsequently, at 1050 ° C., TMG gas and ammonia gas are similarly used as source gas, and silane gas (SiH) is used as impurity gas._Four) And Si is 4.5 × 10¹⁸/ Cm^ThreeAn n-type contact layer made of doped n-type GaN is grown to a thickness of 4 μm.
[0030]
(Light emitting layer 4)
Next, the carrier gas is switched to nitrogen, a barrier layer made of undoped InAlGaN is grown to a thickness of 250 mm, the temperature is subsequently lowered to 800 ° C., and TEG gas, TMI (trimethylindium) gas and ammonia gas are used as source gases. Undoped In_xGa_1-xA well layer made of N (0 <x ≦ 1) is grown to a thickness of 30 mm. Then, 6 barrier layers and 5 well layers are alternately laminated in the order of barrier layer + well layer + barrier layer + well layer +. Grow.
[0031]
(P-type nitride semiconductor layer 5)
Next, after stopping the source gas and raising the temperature to 1050 ° C., TEG gas, TMA (trimethylaluminum) gas and ammonia gas as source gas, hydrogen gas as carrier gas, Cp as impurity gas₂Mg (cyclopentadienylmagnesium) is used and Mg is 1 × 10²⁰/ Cm^ThreeDoped Al_0.3Ga_0.7A p-type layer made of N is grown to a thickness of 300 mm.
[0032]
Subsequently, at the same temperature, undoped Al_0.16Ga_0.84A layer made of N is grown to a thickness of 25 mm, followed by 5 × 10 Mg at the same temperature.¹⁸/ Cm^ThreeA layer made of doped p-type GaN is grown to a thickness of 25 mm. A p-type cladding layer having a superlattice structure with a total film thickness of 4000 mm is formed by alternately stacking 80 layers. This layer acts as a carrier confinement layer, and the resistivity on the p-type nitride semiconductor layer side can be reduced by employing a superlattice structure.
[0033]
Finally, at 1050 ° C., on the p-type cladding layer, TMG gas and ammonia gas as source gas, hydrogen gas as carrier gas, Cp as impurity gas₂Mg (cyclopentadienylmagnesium) is used and Mg is 1 × 10¹⁸/ Cm^ThreeA p-type contact layer made of doped GaN is grown to a thickness of 150 mm. In this manner, a p-type nitride semiconductor layer in which the p-type cladding layer and the p-type contact layer are stacked is formed.
[0034]
After completion of the reaction, the wafer is annealed in a reaction vessel at 700 ° C. in a nitrogen atmosphere to further reduce the resistance of the p-type nitride semiconductor layer.
[0035]
Next, leaving the pn stacked portion, the periphery is etched so as to surround the light emitting surface to expose the n-type contact layer.
[0036]
(Positive electrode 6)
Next, on the p-contact layer, a light emitting surface above the cavity is used as an opening, and a positive electrode made of Ni (100 発 光) / Au (1400Å) is formed so as to surround the opening.
[0037]
(Negative electrode 7)
A negative electrode made of Ti (100 Å) / Al (5000 Å) is formed on substantially one surface of the n-type contact layer exposed so as to surround the light emitting surface and the positive electrode.
[0038]
(Insulating film 8)
Next, the pad electrode formation surface of the positive electrode and the negative electrode is used as an opening, and SiO 2₂A continuous insulating film is formed with a film thickness of 2000 mm.
[0039]
(Pad electrodes 9, 10)
Next, as shown in FIG. 1, a p-pad electrode is formed on almost the entire upper surface of the p-type nitride semiconductor layer with the light emitting surface inside the positive electrode as an opening, and an n-pad is formed on a part of the negative electrode. An electrode is formed.
Here, the p pad electrode and the n pad electrode have a three-layer structure of Ni (1000 Å) / Ti (1000 Å) / Au (8000 Å).
[0040]
(First opaque film 11)
Further, an opaque film made of Ni (1000 Å) / Au (1300 Å) is provided from the p pad electrode to the end face of the semiconductor layer.
[0041]
After the back surface of the sapphire substrate of the wafer is polished to a thickness of about 100 μm, the wafer is cleaved at the M surface of the sapphire substrate.
[0042]
(Second opaque film 12)
Finally, a metal thin film made of Al is formed with a thickness of 3000 mm on the side surface of the semiconductor layer corresponding to the outer periphery of the element and the lower surface of the substrate by sputtering.
[0043]
The light emitting diode of Example 1 formed as described above can obtain a minute point light source having a single mode with a spot diameter of 4 μm and a near-field pattern of almost a perfect circle.
[0044]
[Comparative example]
Next, as a comparative example, an edge light emitting device having a ridge structure of an AlGaN / GaN / InGaN separate confinement heterostructure (SCH) without a cavity in the semiconductor layer will be described. The process is the same as in Example 1 until the buffer layer is formed on the substrate.
[0045]
The surface of the substrate 1 made of sapphire (C-plane) is cleaned at 1050 ° C. in a hydrogen atmosphere in a reaction vessel. Subsequently, as in Example 1, the substrate temperature is lowered to 510 ° C. A buffer layer made of GaN is grown on the substrate to a thickness of about 200 Å using hydrogen and TMG (trimethylgallium) gas and ammonia gas as source gases.
[0046]
(N-type nitride semiconductor layer)
Subsequently, TMA (trimethylaluminum), TMG, and ammonia are used at 1050 ° C., and silane gas (SiH) is used as the impurity gas._Four) And Si is 5 × 10¹⁸/ Cm^ThreeDoped n-type Al_0.1Ga_0.9An n-type cladding layer made of N is formed with a film thickness of 0.4 μm.
[0047]
Next, an optical guide layer 103G made of undoped GaN is formed on the n-type cladding layer to a thickness of 0.15 μm.
[0048]
(Light emitting layer)
Next, the temperature is lowered to 800 ° C., the carrier gas is switched to nitrogen, TMG gas, TMI (trimethylindium) gas and ammonia gas are used as the source gas, and a barrier layer made of GaN is formed with a thickness of 50 mm, In_0.3Ga_0.7A well layer composed of N is formed in order with a thickness of 30 mm, and a light emitting layer composed of a three-layer repeated multiple quantum well structure is formed.
[0049]
(P-type nitride semiconductor layer)
Next, a light guide layer made of undoped GaN is formed on the light emitting layer with a thickness of 0.15 μm.
[0050]
Next, after stopping the source gas and raising the temperature to 1050 ° C., TMG gas, TMA (trimethylaluminum) gas and ammonia gas as source gas, hydrogen gas as carrier gas, Cp as impurity gas₂Mg (cyclopentadienylmagnesium) is used and Mg is 1 × 10²⁰/ Cm^ThreeDoped Al_0.1Ga_0.9A p-type cladding layer made of N (0 <x ≦ 1) is grown to a thickness of 0.4 μm.
[0051]
Subsequently, the TMA gas is stopped, and TMG gas and ammonia gas as source gases, hydrogen gas as carrier gas, and Cp as impurity gas on the p-type cladding layer at the same temperature.₂Mg (cyclopentadienylmagnesium) is used and Mg is 5 × 10¹⁸/ Cm^ThreeA p-type contact layer made of doped GaN is grown to a thickness of 0.1 μm.
[0052]
Next, a ridge structure is formed by etching from the p-type contact layer to the p-type cladding layer. The p-type cladding layer exposed on one side of the ridge stripe is etched to expose the n-type contact layer that forms the n-electrode.
[0053]
(electrode)
A positive electrode made of Ni / Au is formed on the entire surface of the ridge. Next, the surface of the p-type cladding layer and the p-type contact layer excluding the positive electrode is made of SiO.₂An insulating film is formed, and a p-pad electrode is formed on the positive electrode through this insulating film. On the other hand, a negative electrode made of Ti and Al is formed on the n-type contact layer exposed earlier.
[0054]
The edge-emitting light-emitting device obtained in this way can provide a minute point light source having a vertical spot size of 6 μm and a near-field pattern consisting of a plurality of elliptical peaks.
[0055]
As described above, in the comparative example, the emission intensity peaks are observed in the optical waveguide, the n-type cladding layer, and the n-type contact layer each composed of the light-emitting layer and the light guide layer. Is capable of emitting a single spot light with high output by condensing the light on the outer wall of the cavity having a reverse taper shape and totally reflecting it upward.
[0056]
【The invention's effect】
As described above in detail, in the nitride semiconductor light emitting device according to the present invention, the semiconductor layer has a cavity that penetrates at least from the light emitting layer to the n-type nitride semiconductor layer and has a side surface having a reverse tapered shape. The light emitted from each layer on the side surface can be condensed and totally reflected upward, and single mode light having a spot diameter corresponding to the bottom surface of the cavity can be emitted with high output.
In addition, the method for manufacturing a surface-emitting light-emitting device of the present invention can easily set a single layer having any spot diameter and spot shape by setting the size and shape of the mask layer provided on the substrate corresponding to the required spot diameter. Mode light can be output.
Therefore, according to the present invention, there is provided a surface-emitting light-emitting element that has a small spot size and can obtain uniform light as a micro light source used for optical fiber communication or electrophotographic light sources or virtual reality. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a surface-emitting light emitting device according to the present invention.
FIG. 2 is a schematic cross-sectional view taken along the line AA ′ in FIG.
[Explanation of symbols]
1 ... Board
2 ... Mask layer
3 ... n-type nitride semiconductor layer
4 ... Light emitting layer
5 ... p-type nitride semiconductor layer
6 ... Positive electrode
7 ... Negative electrode
8 ... Insulating film
9 ... P pad electrode
10 ... n pad electrode
11: First opaque film
12: Second opaque film
13 ... Cavity

Claims (3)

A substrate,
A semiconductor layer having an n-type nitride semiconductor layer, a light emitting layer, and a p-type nitride semiconductor layer in this order on the substrate;
In the semiconductor layer, a cavity covered with an n-type nitride semiconductor layer, a light emitting layer, and a p-type nitride semiconductor layer; and
A region corresponding to the cavity as viewed from the p-type nitride semiconductor layer side as an opening, and a p-electrode provided around the opening on the p-type semiconductor layer,
The surface-emitting light-emitting element is characterized in that light from the light-emitting layer is reflected toward the p-type nitride semiconductor layer by the cavity and can be extracted to the outside through the opening. The surface-emitting light emitting device according to claim 1, wherein the substrate is made of a material having a refractive index smaller than that of the semiconductor layer. The surface-emitting light-emitting element further has an opaque film,
3. The surface-emitting light emitting device according to claim 1, wherein the opaque film is provided by opening a region corresponding to the cavity as viewed from the p-type nitride semiconductor layer side. element.

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