JP2010278145A - Light-emitting element and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting element in which a side wall of a substrate includes at least first and second structure surfaces, here, the first structure surface is substantially a flat surface, and the second structure surface is substantially a non-flat surface, and to provide a method of manufacturing the same. <P>SOLUTION: A method of manufacturing a light-emitting element includes: a step of providing a substrate having first and second main surfaces; a step of forming a plurality of light-emitting stack layers on the first main surface of the substrate; a step of forming an etching protection layer on the plurality of light-emitting stack layers; a step of forming a plurality of discontinuous holes on the substrate by discontinuous laser beam; a step of etching the plurality of discontinuous holes; and a step of cutting the substrate along the plurality of discontinuous holes. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device, and in particular, a side wall of a substrate includes at least a first structure surface and a second structure surface, wherein the first structure surface is a substantially flat surface, and the second structure surface The present invention relates to a light emitting device having a substantially uneven surface and a method for manufacturing the same.

  The light emission principle of a light emitting diode (LED) is to release energy in the form of light by utilizing the difference in energy generated when electrons move between the n-type semiconductor layer and the p-type semiconductor layer. Since such a light emission principle is completely different from the light emission principle of incandescent lamps due to heat generation, the light emitting diode is called a cold light source. In addition, since it has advantages such as high durability, long life, small size, light weight, and low power consumption, the light emitting diode has become a new generation lighting fixture instead of the traditional light source. Currently, light emitting diodes are applied in various fields related to traffic signs, backlight modules, street lamp lighting, medical equipment, and the like.

  FIG. 1 is a diagram illustrating a structure of a conventional light emitting device. As shown in FIG. 1, a conventional light emitting device 100 includes a transparent substrate 10, a semiconductor stack layer 12 positioned on the transparent substrate 10, and at least one electrode 14 positioned on the semiconductor stack layer 12, where The semiconductor stack layer 12 described above includes at least a first conductivity type semiconductor layer 120, an active layer 122, and a second conductivity type semiconductor layer 124 from top to bottom.

  In addition, the light-emitting element 100 described above can be combined with other elements to form a light-emitting device. FIG. 2 is a diagram illustrating a structure of a conventional light emitting device. As shown in FIG. 2, the light emitting device 200 includes a submount 20 having at least one circuit 202 and at least one solder 22 positioned on the submount 20, and the light emitting element 100 is attached to the submount 20 by the solder 22. The solder 22 for electrically connecting the substrate 10 of the light emitting element 100 to the circuit 202 of the submount 20 and the electrical connection structure 24 for electrically connecting the electrode 14 of the light emitting element 100 to the circuit 202 of the submount 20. In this case, the submount 20 described above may be a lead frame or a large-sized mount substrate, which facilitates the layout of the circuit of the light emitting device 200 and also improves the heat dissipation effect. it can.

  However, as shown in FIG. 1, in the conventional light emitting device 100, the surface of the transparent substrate 10 is a flat surface, and the refractive index of the transparent substrate 10 is different from the refractive index of the external environment. When the emitted light A enters the external environment from the substrate, total reflection is likely to occur, and the light output rate of the light emitting element 100 is reduced.

  It is an object of the present invention that the side wall of the substrate includes at least a first structural surface and a second structural surface, wherein the first structural surface is a substantially flat surface, and the second structural surface is substantially An object of the present invention is to provide a light emitting device having a non-planar surface and a method for manufacturing the same.

  In order to achieve the above object, the present invention provides a light emitting device. The light-emitting element includes at least a substrate and a light-emitting stack layer positioned on the substrate, and the substrate has at least one side wall, and the side wall includes at least a first structure surface and a second structure. The first structural surface is a substantially flat surface and the second structural surface is a substantially uneven surface.

  The present invention also provides other light emitting elements. The light-emitting element includes at least a substrate and a light-emitting stack layer positioned on the substrate, and the substrate has at least one side wall, and the side wall includes at least a first structure surface and a second structure. Including a substantially discontinuous structure of surfaces, the first structural surface being a substantially flat surface and the second structural surface being a substantially uneven surface. This substantially discontinuous structure of the substrate sidewall improves the light output rate of the light emitting element.

  The present invention also provides a method for manufacturing a light emitting device. The manufacturing method includes providing a substrate having a first major surface and a second major surface, forming a semiconductor epitaxial layer on the first major surface of the substrate, and an etching protection layer on the semiconductor epitaxial layer. Forming a plurality of discontinuous holes in the substrate with the discontinuous laser beam, etching the plurality of discontinuous holes, and along the plurality of discontinuous holes. Cutting to form a light emitting element.

  In the present invention, the side wall of the substrate includes at least a first structure surface and a second structure surface, wherein the first structure surface is a substantially flat surface, and the second structure surface is substantially uneven. Provided are a light emitting device having a smooth surface and a method for manufacturing the same.

It is a figure which shows the structure of the conventional light emitting element. It is a figure which shows the structure of the conventional light-emitting device. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure in the manufacturing process of this invention. It is a figure which shows the structure of the Example which concerns on this invention. It is a figure which shows the structure of the other Example which concerns on this invention. It is a figure which shows the structure of the other Example which concerns on this invention. It is a figure which shows the microstructure by the scanning electron microscope of the Example which concerns on this invention.

  Next, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  3A to 3I are diagrams showing the structure in the manufacturing process of the present invention.

  First, as shown in FIG. 3A, a substrate 30 is provided, where the substrate 30 includes a first major surface 302 and a second major surface 304. Next, as shown in FIG. 3B, a plurality of semiconductor epitaxial layers 31 are formed on the first main surface 302 of the substrate 30, where the semiconductor epitaxial layers 31 are at least a first conductivity type from bottom to top. A semiconductor layer 310, an active layer 312, and a second conductivity type semiconductor layer 314 are included.

Subsequently, as shown in FIG. 3C, by etching the semiconductor epitaxial layer 31 described above by lithography / etching technology, a part of the substrate 30 is exposed, and the semiconductor epitaxial layer 31 has a plurality of trapezoidal structures. The light emitting stack layers 32 are formed, and each light emitting stack layer 32 exposes a part of the first conductivity type semiconductor layer 310. Next, as shown in FIG. 3D, an etching protective layer 34 is formed on the light emitting stack layer 32. In other embodiments, the etching protective layer 34 may cover the light emitting stack layer 32 and the substrate 30 at the same time. Here, the material of the etching protection layer 34 described above may be silicon dioxide (SiO ₂ ) or silicon nitride (SiNx). Thereafter, as shown in FIG. 3E, a plurality of discontinuous holes 36 are formed in the first main surface 302 of the substrate 30 by the discontinuous laser light flux. Here, the “discontinuous laser light flux” In the process of moving the laser beam on the substrate 10, the laser beam is emitted at regular or indefinite time intervals, thereby forming a plurality of discontinuous holes 36 in the first main surface 302 of the substrate 10. In this embodiment, the “discontinuous laser beam” may be an intermittent laser beam such as a pulsed laser beam. FIG. 3F is a diagram showing a structure when FIG. 3E is viewed from above. As shown in FIG. 3F, in the embodiment of the present invention, the discontinuous holes 36 formed by the discontinuous laser beam are distributed so as to surround the plurality of light emitting stack layers 32.

Subsequently, as shown in FIG. 3G, under the condition that the temperature is 100 ° C. to 300 ° C., the aforementioned discontinuous holes 36 are etched for about 10 minutes to 50 minutes with an etching solution. Preferably, under conditions where the temperature is 150 ° C. to 250 ° C., an etching solution having a concentration ratio of sulfuric acid (H ₂ SiO ₄ ) to phosphoric acid (H ₃ PO ₄ ) of 3 to 1 is about 20 minutes to 40 minutes. Etch for minutes. In another embodiment, the etching solution may be a phosphoric acid solution. Finally, as shown in FIG. 3H, the etch protection layer 34 is removed, and the second major surface 304 of the substrate 30 is polished to reduce the thickness of the substrate 30, and then a plurality of discontinuous holes 36. A plurality of light emitting elements 300 are formed by cutting along the line.

  3I, at least the transparent conductive oxide layer 38 may be formed on the light emitting stack layer 32 and then at least the electrode 40 may be formed on the transparent conductive oxide layer 38 before performing the above-described cutting. .

  In addition to this, in the above-described embodiment, a plurality of discontinuous holes 36 are formed by irradiating the first main surface 302 of the substrate 30 with discontinuous laser beams. However, the present invention is not limited to this, and the other positions of the substrate may be irradiated with a discontinuous laser beam. For example, the second main surface 304 of the substrate 30 may be irradiated with a discontinuous laser beam. A second major surface having a plurality of discontinuous holes may be formed.

  4 to 6 are views showing the structure of an embodiment according to the present invention.

  As shown in FIG. 4, the light emitting device 300 includes at least a substrate 30 and a light emitting stack layer 32 positioned on the substrate 30. The substrate 30 includes at least a first major surface 302, a second major surface 304, and at least one sidewall 306, wherein the sidewall 306 of the substrate 30 described above has at least a substantially flat surface. It includes a first structure surface 3060 and a second structure surface 3062 having a substantially uneven surface, wherein the thickness of the second structure surface 3062 is about 5 μm to 20 μm. In this embodiment, the second structural surface 3062 is located near the first major surface of the side wall 306 of the substrate 30, and the substantially uneven surface is formed by a discontinuous laser irradiation and etching process. Here, the concavo-convex structure described above has a stretching direction B, and the stretching direction B is a longitudinal direction. This longitudinal stretching may be stretching from the first major surface 302 of the substrate 30 away from the first major surface 302, stretching from the second major surface 304 of the substrate 30 away from the second major surface 304, or And stretching in the direction from the first major surface 302 to the second major surface of the substrate 30. That is, the stretching direction B has an angle θ with respect to the normal direction C of the first main surface 302, where 0 ° ≦ θ <90 °. In the embodiment described above, the extending direction B of the concavo-convex structure is substantially parallel to the normal direction C of the first main surface 302 of the substrate 30, that is, θ is approximately 0 °.

  In addition, the substrate 30 described above may be a transparent substrate made of sapphire, zinc oxide (ZnO), or the like. In this embodiment, a sapphire substrate is employed. The light emitting stack layer 32 includes, from bottom to top, a first conductive semiconductor layer 310, an active layer 312 and a second conductive semiconductor layer 314, and the material thereof includes Al, Ga, In, As, P, or N. A semiconductor material may be used, for example, a GaN-based material or an AlGaInP-based material. In this embodiment, the material of the light emitting stack layer 32 is a GaN-based material.

  The light emitting device 300 described above further includes a transparent conductive oxide layer 38 positioned on the light emitting stack layer 32 and at least one electrode 40 positioned on the transparent conductive oxide layer 38, where The material of the oxide layer 38 includes one or more materials selected from the group consisting of ITO, InO, SnO, CTO, ATO, AZO, and ZnO.

  FIG. 5 is a diagram showing the structure of another embodiment according to the present invention. In this structure, in addition to the fact that the second structural surface 3062 having a substantially uneven surface is located near the second main surface 304 of the side wall 306, each component, structure, connection relationship, etc. of the light emitting element This is the same as that shown in FIG.

  FIG. 6 is a diagram showing the structure of another embodiment according to the present invention. In this structure, the second structure surface 3062 having a substantially non-planar surface is located at the center of the side wall 306 of the substrate 30, and the upper and lower sides of the second structure surface 3062 are all substantially flat. Other than 3060, each component, structure, connection relationship, and the like of the light emitting element are the same as those shown in FIG.

  FIG. 7 is a diagram showing a microstructure of a scanning electron microscope according to an embodiment of the present invention. As shown in FIG. 7, the second structure surface 3062 of the substrate 30 is an uneven surface having an uneven structure.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and all modifications to the present invention are within the scope of the present invention unless departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 100 Light emitting element 10 Transparent substrate 12 Semiconductor stack layer 14 Electrode 120 First conductive type semiconductor 122 Active layer 124 Second conductive type semiconductor 200 Light emitting device 20 Submount 202 Circuit 22 Solder 24 Electrical connection structure 30 Substrate 302 First main surface 304 First Two main surfaces 306 Side walls 32 Semiconductor stack layer 320 First conductive type semiconductor layer 322 Active layer 324 Second conductive type semiconductor layer 326 Trapezoidal structure 34 Etching protective layer 36 Hole 300 Light emitting element 38 Transparent conductive oxide layer 40 Electrode 3060 First structure Surface 3062 second structure surface

Claims (14)

A method for manufacturing a light emitting device, comprising at least:
Providing a substrate having a first major surface and a second major surface;
Forming a plurality of light emitting stack layers on a first major surface of the substrate;
Forming an etching protection layer on the plurality of light emitting stack layers;
Forming a plurality of discontinuous holes in the substrate by discontinuous laser light;
Etching the plurality of discontinuous holes;
Cutting the substrate along the plurality of discontinuous holes;
including,
Manufacturing method of light emitting element. Further comprising removing the etch protection layer.
The manufacturing method of the light emitting element of Claim 1. The step of forming the plurality of light emitting stack layers includes at least:
Forming a first conductivity type semiconductor layer on a first major surface of the substrate;
Forming an active layer on the first conductivity type semiconductor layer;
Forming a second conductivity type semiconductor layer on the active layer;
Etching the first conductive semiconductor layer, the active layer, and the second conductive semiconductor layer by a lithography / etching technique to form a plurality of trapezoidal light emitting stack layers;
including,
The manufacturing method of the light emitting element of Claim 1. Etching the plurality of discontinuous holes is etching for 10 minutes to 50 minutes with an etchant under conditions where the temperature is 100 ° to 300 °.
The manufacturing method of the light emitting element of Claim 1. The etching solution is a solution having a component ratio of sulfuric acid and phosphoric acid of 3 to 1, or a phosphoric acid solution.
The manufacturing method of the light emitting element of Claim 4. In the step of forming the plurality of discontinuous holes in the substrate by the discontinuous laser light, the discontinuous laser light is intermittent laser light.
The manufacturing method of the light emitting element of Claim 1. In the step of forming the plurality of discontinuous holes in the substrate by the discontinuous laser light, the plurality of discontinuous holes are formed in the first main surface or the second main surface.
The manufacturing method of the light emitting element of Claim 1. And forming at least an electrode on the light emitting stack layer, and forming a transparent conductive oxide layer between the light emitting stack layer and the electrode.
The manufacturing method of the light emitting element of Claim 1. A light emitting device, at least,
A substrate having at least a first major surface, a second major surface and sidewalls;
A light emitting stack layer located on the substrate;
Including
The side wall of the substrate includes at least a first structure surface and at least a second structure surface, the first structure surface being a substantially flat surface, and the second structure surface being substantially uneven. The surface is
Light emitting element. The second structure surface has an uneven structure,
The light emitting device according to claim 9. The concavo-convex structure has a stretching direction;
The stretching direction is a longitudinal direction, which is a direction substantially parallel to the normal direction of the main surface of the substrate.
The light emitting device according to claim 10. The concavo-convex structure extends along a direction from the first main surface toward the second main surface, extends along a direction away from the first main surface, or the second main surface. Stretching along a direction away from the second major surface from the surface;
The light emitting device according to claim 10. The second structural surface is formed on a side wall of the substrate at a location close to the first main surface or the second main surface.
The light emitting device according to claim 9. The second structure surface is formed on a side wall of the substrate, and the top and bottom of the second structure surface are all the first structure surface.
The light emitting device according to claim 9.

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