TW201622174A - Light emitting element and method for producing light emitting element - Google Patents

Abstract

The present invention provides a light emitting element which comprises a supporting substrate that also serves as a window layer and a light emitting part that is provided on the window layer/supporting substrate and sequentially comprises a second semiconductor layer of a second conductivity type, an active layer and a first semiconductor layer of a first conductivity type in this order. This light emitting element is characterized in that: a first ohmic electrode is provided on the first semiconductor layer with a first selective etching layer being interposed therebetween; the surface of the first semiconductor layer and at least a part of the lateral surface of the light emitting part are covered by an insulating protective film; and the surface of the first semiconductor layer and the surface of the window layer/supporting substrate are subjected to surface roughening. Consequently, the present invention provides a light emitting element which comprises a window layer/supporting substrate and a light emitting part and performs element isolation, while being suppressed in electrode separation from the surface of the light emitting part and having improved luminous efficiency.

Description

Light-emitting element and method of manufacturing the same

The present invention relates to a light-emitting element and a method of fabricating the same, and more particularly to forming a first semiconductor layer, an active layer, a second semiconductor layer, and a window layer supporting substrate by epitaxial growth, and removing the substrate Then, the structure and the manufacturing method when the surface of the light-emitting element substrate on which the electrode is formed are subjected to surface roughening treatment are applied.

In recent years, light-emitting diodes (LEDs) have progressed toward high efficiency and have progressed toward applications for lighting devices. Conventional lighting devices are almost all devices made up of InGaN-based blue LEDs and phosphors. However, when a fluorescent agent is used, since the principle of Stokes loss cannot be avoided, there is a problem that the fluorescent agent cannot convert all the received light into another wavelength. This problem is particularly pronounced especially in the range of yellow and red, which are relatively blue with long wavelengths.

In order to solve this problem, the technology adopted in recent years is a combination of yellow or red LEDs and blue LEDs. At this time, it is not a COB (chip on board) type that extracts light on one side surface, and a bulb type lighting device in which LEDs are arranged side by side on a board and emits light in a wire type is gradually popularized. The LED component used in this type of device is not suitable for extracting light from a single side of the component because it has to be extended to the entire surface of the wire, and the ideal component is a device that extracts light from the global surface of the chip. Light.

Generally, a sapphire substrate is used for an InGaN-based LED which is a blue LED, and since the sapphire substrate is transparent with respect to an emission wavelength, it is an ideal form for the aforementioned illumination device. However, for a yellow or red LED, GaAs or Ge which is a light absorbing substrate with respect to an emission wavelength is used as a starting substrate, and is not suitable for the aforementioned use.

In order to solve this problem, a method of bonding a transparent substrate to a light-emitting portion as disclosed in Patent Document 1 and a method of growing a window layer to a thickness capable of supporting a substrate as disclosed in Patent Document 2 are disclosed. A technique of light-absorbing a starting substrate of a substrate to become an LED.

In the method disclosed in Patent Document 1, since it is necessary to bond a transparent substrate having a required thickness or more, and it is necessary to thin the substrate to a predetermined thickness after bonding, it becomes a factor of cost increase. Further, the substrate generally used for bonding has a thickness of 200 μm or more. Since the film thickness required for the LED element is at most about 100 μm in consideration of the light distribution characteristics and the combination with other elements, it is necessary to form a film thickness to such a thickness. In the thin film processing, the increase in the number of operating hours and the risk of wafer breakage due to processing become factors that increase the cost and decrease the yield.

On the other hand, in the method of growing a window layer which can be used for a supporting substrate by crystal growth as disclosed in Patent Document 2, it is only necessary to grow the window layer to a desired thickness. It is an excellent method because it can be formed at a low cost without performing a step of thin film forming or substrate bonding or adhesion.

Further, in the above-described light-emitting element having a transparent supporting substrate, a method generally adopted is to improve luminous efficiency by preventing multiple reflection inside the light-emitting element and suppressing light absorption. Patent Document 3 proposes to apply a surface to a window layer and a current supporting diffusion layer and a window layer supporting substrate in a structure in which a thick window layer and a current diffusion layer and a thick window layer and a supporting substrate sandwich the light emitting portion. Roughening, a method of roughening the surface of the light-emitting portion is not applied. However, in this method, it is necessary to form a deep trench penetrating through the window layer and the current diffusion layer portion. This method not only increases the cost, but also makes the wire bonding difficult because the height difference between the upper and lower electrodes is too large. Even when applied to a flip chip type, it is necessary to form a thick insulating film and a very long metal via, which causes a cost increase. Therefore, it is desirable that the window layer and the current diffusion layer which are the upper electrode portions are thin.

Patent Literatures 4 and 5 are disclosed as a technique for revealing that the thickness of the window layer and the current diffusion layer is small, the height difference between the upper electrode portion and the lower electrode portion is small, and the light extraction portion or the light reflection portion has a rough surface. In Patent Document 4, although a rough surface is formed on the surface of the n-type semiconductor layer on the side of the light extraction surface and the opposite side, it is disclosed in the technique of the flip chip type, and light that is efficiently emitted from the electrode side is reflected to the side of the window layer. purpose. Further, it has been revealed that it is difficult to roughen both surfaces of the window layer supporting substrate and the light emitting portion.

Patent Document 5 discloses a technique in which the surface of the light-emitting portion is roughened and has a platform shape or a simple platform shape at different angles on the side surface of the light-emitting portion. At this time, a reflective structure in which surface roughening is unnecessary is employed on the substrate. Further, a technique of forming irregularities such as a period of 2 μm by the lithography method on the surface of the light-emitting portion is also disclosed.

On the other hand, in the case where the window layer and the supporting substrate are formed by epitaxial growth, the substrate has large warpage due to lattice mismatch, and even by the contact exposure method, the surface of the light-emitting portion is formed to be 2 μm or less by the lithography method. The uniform pattern of spacing is also extremely difficult. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5, 427, 585 [Patent Document 3] Japanese Patent No. 4, 569, 858 (Patent Document 3) Japanese Patent No. 4,715, 370 [Patent Document 4] JP-A-2007-059518 (Patent Document 5) ]Japan Special Open 2011-198992

In the light-emitting element having the window layer and the supporting substrate portion and the light-emitting portion, the luminous efficiency has not been sufficient so far. However, in the case where the thin wire electrode is provided on the surface of the light-emitting portion, in order to improve the light-emitting efficiency, once the surface roughening treatment is performed on the surface of the light-emitting portion, there is a problem that over-etching occurs in the lower portion of the thin-line electrode to cause electrode peeling.

In view of the above problems, an object of the present invention is to provide a light-emitting element having a window layer supporting substrate and a light-emitting portion, and in the light-emitting element that performs element separation, peeling of the electrode on the surface of the light-emitting portion can be suppressed and the light-emitting efficiency can be improved.

In order to achieve the above object, the present invention provides a light-emitting element having a window layer and a supporting substrate and a light-emitting portion disposed on the window layer and the supporting substrate, the light-emitting portion sequentially including a second semiconductor of the second conductivity type a layer, an active layer, and a first semiconductor layer of a first conductivity type, wherein the light emitting device has a first ohmic electrode disposed on the first semiconductor layer through a first selective etch layer, and the first At least a portion of a surface of the semiconductor layer and a side surface of the light-emitting portion is covered with an insulating protective film, and a surface of the first semiconductor layer and a surface of the window layer supporting the substrate are surface roughened.

With such a light-emitting element, peeling of the electrode on the surface of the light-emitting portion is suppressed, and since the surface of the first semiconductor layer is not included, the surface including the window layer and the support substrate is also roughened to obtain a larger surface. The roughened area is thus a light-emitting element in which the amount of light extraction is further increased.

In this case, preferably, the light-emitting element has a removed portion excluding the light-emitting portion and a non-removed portion other than the removed portion, and the first selective etching layer is passed through the first semiconductor layer of the non-removed portion. The first ohmic electrode is disposed, and a second ohmic electrode is disposed on the window layer supporting substrate disposed on the removing portion. In this way, the present invention functions particularly effectively while becoming a light-emitting element having a more increased light extraction amount.

In this case, preferably, the substrate is composed of any one of Gap, GaAsP, AlGaAs, sapphire (Al ₂ O ₃ ), SiO ₂ , and SiC, and the first semiconductor layer, the active layer, and the second semiconductor The layer is composed of AlGaInP or AlGaAs. In this manner, as the window layer supporting substrate, the first semiconductor layer, the active layer, and the second semiconductor layer, a material such as the above can be suitably used.

In addition, the present invention provides a method for fabricating a light-emitting device, comprising: selecting an etch layer forming step, forming a selective etch layer on the substrate, the selective etch layer having at least a second selective etch layer and a first selective etch a light-emitting portion forming step of sequentially growing a first semiconductor layer, an active layer, and a second semiconductor layer by epitaxial growth on the selective etching layer to form a lattice matching system with the substrate Forming a light-emitting portion; the window layer and the supporting substrate forming step are formed on the light-emitting portion to form a window layer and a supporting substrate by epitaxial growth of the material of the substrate as an amorphous matching system; Removing the substrate and the second selective etch layer, and leaving only the first selective etch layer on the surface of the first semiconductor layer; the first ohmic electrode forming step is formed on the surface of the first selective etch layer An ohmic electrode; a first selective etch layer removing step of removing the first selective etch layer in a region other than a lower portion of the first ohmic electrode; a first surface roughening step, Performing a surface roughening treatment on the surface of the first semiconductor layer; a component separating step of forming a removed portion excluding a portion of the light emitting portion and a non-removing portion other than the light emitting portion; and a second ohmic electrode forming step of removing the light emitting portion a second ohmic electrode is formed on the window layer and the supporting substrate; the covering step covers the surface of the first semiconductor layer and at least a portion of the side surface of the light emitting portion with an insulating protective film; and the second surface roughening step is rough The window layer also supports the surface and the side surface of the substrate.

According to such a manufacturing method, the peeling of the electrode on the surface of the light-emitting portion can be suppressed at a relatively low cost, and the surface of the first semiconductor layer and the surface of the window layer can support the surface roughening of the substrate surface. Light-emitting element with luminous efficiency.

In this case, preferably, the substrate is GaAs or Ge, and the window layer and the supporting substrate are any one of Gap, GaAsP, AlGaAs, sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, and the first semiconductor. The layer, the active layer, and the second semiconductor layer are AlGaInP or AlGaAs. In this manner, as the substrate, the window layer supporting substrate, the first semiconductor layer, the active layer, and the second semiconductor layer, the above-described materials can be suitably used.

In this case, preferably, the first surface roughening treatment step is performed by using a mixture of an organic acid and a mineral acid, and the organic acid comprises: any one of citric acid, malonic acid, formic acid, acetic acid, and tartaric acid. In the above, the inorganic acid comprises: at least one of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid; and in the second surface roughening step, a mixture of an organic acid and an inorganic acid is used, and the organic acid comprises: Any one or more of citric acid, malonic acid, formic acid, acetic acid, and tartaric acid, and the inorganic acid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid, and the mixed solution contains iodine.

In this way, the surface of the surface can be surely roughened.

According to the present invention, it is possible to suppress the peeling of the electrode on the surface of the light-emitting portion, and it is possible to obtain a larger surface roughened by not only roughening the surface of the first semiconductor layer but also the surface of the window layer and supporting the surface of the substrate. A light-emitting element having an increased amount of light extraction is realized. Further, in the method for producing a light-emitting device of the present invention, the surface of the first semiconductor layer and the window layer can be supported by roughening the surface of the surface of the light-emitting portion at a relatively simple and low cost. A light-emitting element that improves the light-emitting efficiency by the surface of the substrate.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited thereto.

First, a light-emitting element of the present invention will be described with reference to Fig. 1. As shown in FIG. 1, the light-emitting element 1 of the present invention has a window layer and a supporting substrate 107, and a light-emitting portion 108 provided on the window layer-supporting substrate 107. The light-emitting portion 108 sequentially includes a second conductive portion. The second semiconductor layer 105 of the type, the active layer 104, is a first semiconductor layer 103 of the first conductivity type.

The window layer and support substrate 107 can be composed of Gap, GaAsP, AlGaAs, sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, etc., and the first semiconductor layer 103, the active layer 104, and the second semiconductor layer 105 can It consists of AlGaInP or AlGaAs.

Preferably, the light-emitting element 1 has at least the first semiconductor layer 103 and the removed portion 170 of the active layer 104 from which the light-emitting portion 108 is removed, and a non-removed portion 180 other than the removed portion 170. A first ohmic electrode 121 disposed on the first semiconductor layer 103 of the 180 through the first selective etching layer 102B, and a second ohmic electrode 122 disposed on the window layer of the removing portion 170 and the supporting substrate 107.

The surface of the first semiconductor layer 103 and at least a portion of the side surface of the light-emitting portion 108 are covered by an insulating protective film 150. The surface of the first semiconductor layer 103, the surface of the window layer and the supporting substrate 107, and the side surface thereof are The surface is roughened.

According to the light-emitting element 1 of the present invention, the peeling of the electrode on the surface of the light-emitting portion is suppressed, and since the surface is roughened, not only the surface of the first semiconductor layer but also the surface of the window layer and the supporting substrate can be larger. The area on which the surface is roughened is extracted, and thus the light-emitting element having a larger amount of light extraction is obtained.

Next, a method of manufacturing the light-emitting element of the present invention will be described with reference to Figs. 2 to 8. First, as shown in Fig. 3, a substrate 101 (SP1 of Fig. 2) is prepared as a starting substrate.

As the substrate 101, GaAs or Ge can be suitably used. In this manner, since the material of the active layer 104 to be described later can be epitaxially grown by the lattice matching system, the quality of the active layer 104 can be easily improved, and the brightness can be improved or the life characteristics can be improved.

Next, a selective etching layer 102 is formed on the substrate 101 (SP2 of FIG. 2). The selective etching layer 102 can be formed on the substrate 101 by, for example, MOVPE method (organic metal vapor deposition method), MBE (molecular beam epitaxy method), or CBE (chemical beam epitaxy method). The selective etching layer 102 is composed of two or more layer structures, and has at least a second selective etching layer 102A that is in contact with the substrate 101 and a first selective etching layer 102B that is in contact with the first semiconductor layer 103 to be described later. Preferably, the second selective etch layer 102A and the first selective etch layer 102B are formed of different materials or compositions.

Next, by the epitaxial growth, the first semiconductor layer 103 of the first conductivity type, the active layer 104, and the second semiconductor layer 105 of the second conductivity type which are lattice-matched with the substrate 101 are sequentially grown to form a light emission. Part 108 (SP3 of Fig. 2).

Next, on the light-emitting portion 108, the window layer-supporting substrate 107 is formed by epitaxial growth of the material for the substrate 101 as an amorphous matching system, thereby forming the epitaxial substrate 109 (SP4 of Fig. 2).

Specifically, in the above-described SP3, 4, as shown in FIG. 3, for example, the light can be composed of the first semiconductor layer 103 of the first conductivity type, the active layer 104, and the second semiconductor layer 105 of the second conductivity type. On the portion 108, an epitaxial substrate 109 which is epitaxially grown in the order of the buffer layer 106 and the window layer and the support substrate 107 is formed. Further, the window layer and supporting substrate 107 can also be formed by the HVPE method (hydride vapor deposition method).

The active layer 104 is in response to the wavelength of light and is (Al _x Ga _{l -x} ) _y In _1-y P (0≦x≦1, 0.4≦y≦0.6) or Al _z Ga _lz As (0≦z≦0.45). Was formed. In the case of visible light illumination, AlGaInP is suitable for use in the case of infrared illumination, and AlGaAs is suitable. However, regarding the design of the active layer 104, since the wavelength can be adjusted to a wavelength other than the material component by using a superlattice or the like, it is not limited to the above materials.

The first semiconductor layer 103 and the second semiconductor layer 105 may be selected from AlGaInP or AlGaAs, even if the same material as the active layer 104 is not selected.

In the present embodiment, the first semiconductor layer 103, the active layer 104, and the second semiconductor layer 105 having the simplest structure are all in the same material as the AlGaInP, as an example, in order to enhance the first semiconductor layer 103 or The characteristics of the second semiconductor layer 105 generally include a plurality of layers in each layer, and the first semiconductor layer 103 or the second semiconductor layer 105 is not limited to a single layer.

As the window layer and supporting substrate 107, Gap, GaAsP, AlGaAs, sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, or the like can be suitably used. In the case where the window layer and the support substrate 107 are formed of Gap, GaAsP, AlGaAs, sapphire (Al ₂ O ₃ ), SiO ₂ , SiC, or the like, the buffer layer 106 is preferably formed by GaInp, but the buffer layer 106 may have The material of the buffer function may be selected from any one of the materials, that is, the material of the buffer layer is not limited thereto. Further, the window layer and the supporting substrate 107 can also be formed of AlGaAs which is a material of a lattice matching system. Further, as the window layer and supporting substrate 107, GaAsP is selected, and the weather resistance is good. However, since there is a large lattice mismatch with GaAsP, AlGaInP-based materials, or AlGaAs-based materials, high-density strain or through-type difference is infiltrated into GaAsP. As a result, the epitaxial substrate 109 has a large warpage.

Here, preferably, in order to prevent wavelength drift due to formation of a natural superlattice, the light-emitting portion 108 is grown with a crystallographic inclination of 12 degrees or more with respect to the growth surface. Although the direction of the inclination can be selected in any one of the directions, in the case where the step of separating the elements by the step of dicing and slashing is employed, if the side of the scribe line is selected, the direction in which the crystal axis is not inclined and orthogonal is selected, and the scribed line is scribed. On the other hand, the direction in which the crystal axis is inclined is selected, that is, the surface on the side of the element which is inclined with respect to the surface of the element and the inner surface can be reduced. Therefore, generally, the one side of the scribe line is selected in a direction in which it is not inclined, and the inclination of the side surface of the element of about 20 degrees does not have much problem in the assembly. Therefore, the above-described orthogonal directions do not have to be strictly identical, and an angular range of about ±20 degrees from the orthogonal direction is conceptually included in the orthogonal direction.

Next, the substrate 101 and the second selective etching layer 102A are removed from the epitaxial substrate 109, and the first selective etching layer 102B is left alone on the surface of the first semiconductor layer 103 of the light-emitting element substrate 110 shown in FIG. 2 Figure SP5). Specifically, the first selective etching layer 102B can be left alone on the surface of the first semiconductor layer 103 by the wet etching method and using the second selective etching layer 102A to remove the substrate 101 from the epitaxial substrate 109.

Next, as shown in Fig. 5, on the surface of the first selective etching layer 102B, a first ohmic electrode 121 (see SP6 in Fig. 2) for supplying a potential to the light-emitting element is formed.

Next, as shown in FIG. 5, the first selective etching layer 102B in the region other than the lower portion of the first ohmic electrode 121 is removed (SP7 in Fig. 2). Specifically, the first ohmic electrode 121 is an etch mask, and the first selective etch layer 102B in a region other than the lower portion of the first ohmic electrode 121 can be removed by etching.

Next, as shown in FIG. 6, a first surface roughening treatment step (SP8 of FIG. 2) for performing surface roughening treatment on the surface of the first semiconductor layer 103 is performed.

The first surface roughening treatment step is carried out by using a mixed solution of an organic acid and an inorganic acid, and as the carboxylic acid of the organic acid, any one of citric acid, malonic acid, formic acid, acetic acid, and tartaric acid can be used. As described above, the inorganic acid can be used in any one or more of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid. In this way, the surface of the surface can be surely roughened.

Preferably, the Ra (arithmetic mean roughness) of the roughness of the rough surface of the surface of the first semiconductor layer 103 when the surface roughening is performed in the first surface roughening treatment step is set to 0.3 μm or more. The first roughening liquid forms a facet along the shape of the first ohmic electrode by forming the first selective etching layer 102B with a material having selective etching properties with respect to the first rough liquid. Since the occurrence of overetching of the lower portion of the first ohmic electrode 121 can be prevented by providing the first selective etching layer 102B on the lower portion of the first ohmic electrode 121, peeling of the electrode on the surface of the light emitting portion can be suppressed.

Next, as shown in Fig. 7, an element separation step (SP9 in Fig. 2) for forming the removed portion 170 from which a part of the light-emitting portion 108 is removed and the non-removed portion 180 other than the light-emitting portion 108 is formed.

The element separating step can form a pattern in which a predetermined region (the second ohmic electrode forming region 140, the scribe line region 141 in FIG. 6) on the first semiconductor layer 103 is formed with a photoresist by, for example, a lithography method, and This photoresist is used as an etch mask for etching. The etching is performed by a wet etching method using a wet etching solution containing hydrochloric acid, and the second semiconductor layer 105, the removing portion 170 for exposing the buffer layer 106 or the window layer supporting substrate 107, and the removing portion 170 can be formed. Other than the removal unit 180.

Further, in the element separation step, in addition to the wet etching method exemplified above, it is preferably carried out by a dry etching method such as an RIE method or an ICP method using a gas containing a halogen gas or hydrogen chloride. .

Next, as shown in Fig. 8, the second ohmic electrode 122 (SP10 of Fig. 2) is formed on the removed portion 170 on the window layer-supporting substrate 107 from which the light-emitting portion 108 is removed.

Next, as shown in FIG. 8, at least a part of the surface of the first semiconductor layer 103 and the side surface of the light-emitting portion 108 is covered with the insulating protective film 150 (SP11 of Fig. 2). Any one of the materials may be used as long as the insulating protective film 150 is a transparent and insulating material. As the insulating protective film 150, for example, SiO ₂ or SiN _X can be suitably used. With such a material, the upper portions of the first ohmic electrode 121 and the second ohmic electrode 122 can be easily opened by the lithography method and the etching solution containing hydrofluoric acid.

Next, as shown in FIG. 1, the second surface roughening treatment step is performed to roughen the surface and the side surface of the window layer supporting substrate 107 (SP12 in Fig. 2).

Before performing the second surface roughening treatment, first, the scribe line is cut along the removal portion 170, and preferably, the light-emitting element is separated by performing the cleavage to form the light-emitting element crystal grains. After the light-emitting element crystal grains are formed, preferably, the light-emitting element crystal grains are transferred to the carrier tape and moved to the upper surface of the window layer-supporting substrate 107, and then the second surface roughening treatment described below is performed.

The first surface roughening treatment step is carried out by using a mixed solution of an organic acid and an inorganic acid, and the organic acid can use any one or more of citric acid, malonic acid, formic acid, acetic acid, and tartaric acid, and the inorganic acid can be used. Any one or more of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid is contained, and the mixed solution can contain iodine. In this way, the surface of the surface can be surely roughened.

When the surface roughening is performed in the second surface roughening treatment step, Ra (arithmetic mean roughness) of the roughness of the surface of the window layer and the support substrate 107 and the rough surface of the side surface is set to 0.3 μm or more. a first surface roughening agent applied to the first semiconductor layer 103 used in the first surface roughening treatment step mentioned above, and a second surface applied to the window layer and supporting substrate 107 in the second surface roughening treatment step A roughening agent whose liquid components are different. Accordingly, since the etching characteristics different reasons, and will inevitably has a shape of the first semiconductor layer 103 and the window layer and the support substrate 107 and the roughened surface R _a is different.

In the method for producing a light-emitting device of the present invention described above, it is possible to suppress the peeling of the electrode on the surface of the light-emitting portion, and also to roughen the surface of the first semiconductor layer 103, the surface of the window layer and the support substrate 107, and the side surface. . In this way, since a larger surface roughening area can be taken, a light-emitting element having an increased light extraction amount and improved luminous efficiency can be manufactured. [Examples]

Hereinafter, the present invention will be more specifically described by showing examples and comparative examples of the invention, but the invention is not limited thereto.

<Example 1> An n-type GaAs buffer layer (not shown) was grown by 0.5 μm on an n-type GaAs substrate 101 having a thickness of 280 μm which was inclined by 15° from the [001] direction toward the [110] direction, and was made n-type. The second selective etching layer 102A composed of the AlInP layer is grown by 1 μm, and the first selective etching layer 102B composed of the n-type GaAs layer is grown by 1 μm, and then an n-type cladding layer composed of AlGaInp is formed by the MOVPE method ( a light-emitting portion 108 of 6.5 μm composed of the first semiconductor layer 103), the active layer 104, and the p-type cladding layer (second semiconductor layer 105), and a buffer layer 106 of 0.3 μm composed of p-type InGaP is formed, and A 1 μm layer composed of p-type GaP as a part of the GaP window layer supporting substrate 107 was formed (refer to FIG. 3). Next, moving to the HVPE furnace, the window layer and the supporting substrate 107 composed of p-type GaP were grown by 120 μm to obtain an epitaxial substrate 109.

Next, the GaAs substrate 101, the GaAs buffer layer, and the second selective etching layer 102A are removed, and the light-emitting element substrate 110 in which the first selective etching layer 102B remains is formed (refer to FIG. 4).

Next, a first ohmic electrode 121 is formed on the first selective etching layer 102B of the light-emitting element substrate 110 (refer to FIG. 5), and the lower portion of the first ohmic electrode 121 is removed by an acidic etching solution (SPM) containing a hydrogen peroxide solution. The first selected etch layer 102B of the other regions.

Next, a first surface roughening treatment step is performed on the surface of the first semiconductor layer 103 (refer to FIG. 6). The first surface roughening agent is a mixture of acetic acid and hydrochloric acid, and is subjected to surface roughening treatment at room temperature for 1 minute etching. The roughness of the rough surface of the surface of the first semiconductor layer 103 at this time was measured, and Ra was 0.6 μm.

Next, a region other than the second ohmic electrode forming region 140 and the cleavage region 141 (refer to FIG. 6) is covered with a photoresist by a lithography method, and is performed by a wet etching method using a wet etching solution containing hydrochloric acid. In the element separating step, the removing portion 170 that removes the light-emitting portion 108 and exposes the window layer and the supporting substrate 107 is formed, and the non-removing portion 180 other than the non-removing portion 180 (refer to FIG. 7).

Next, the second ohmic electrode 122 is formed in the removing portion 170 (refer to FIG. 8). Next, an insulating protective film 150 composed of SiO ₂ is laminated, and the surface of the first semiconductor layer 103 and the side surface of the light emitting portion 108 are covered with an insulating protective film 150. Further, the first ohmic electrode 121 and the second ohmic electrode 122 are formed in the insulating protective film 150 by the lithography method and the hydrofluoric acid etching.

Next, the scribe line is cut along the exposed removal portion 170, and the crease line is extended along the scribe line, and thereafter, the element is separated by performing the cleavage to form the light-emitting element crystal grain.

After the light-emitting element crystal grains are formed, the transfer element die is placed on the carrier tape so that the surface on which the first ohmic electrode is provided becomes the tape surface side, and then the second surface roughening treatment step is performed. The surface roughening agent used in the surface roughening of the window layer and the support substrate in the second surface roughening treatment step is a mixed solution of acetic acid, hydrofluoric acid, and iodine. Further, the second surface roughening treatment was performed by etching at room temperature for 1 minute. The roughness of the surface of the window layer and the support substrate 107 and the rough surface of the side surface at this time was measured, and Ra = 0.5 μm.

A light-emitting element was produced by the above method. Then, the light-emitting element produced by silver paste was fixed on TO-18, and then a gold wire was used to make a light bulb, and the light-emitting output was measured. As a result, the light-emitting output was about 60% higher than that of the comparative example described later. In addition, electrode peeling due to surface roughening did not occur.

<Example 2> First, the same processing steps as in Example 1 were carried out up to the first surface roughening treatment step. The roughness of the rough surface of the surface of the first semiconductor layer at this time was measured, and the same Ra as in Example 1 was 0.6 μm.

Next, in order to perform the dry etching method, the first semiconductor layer and the first ohmic electrode are covered with a 300 nm SiO ₂ film, and the photoresist pattern of the predetermined shape is separated by the lithography method. Next, the pattern opening portion is etched by hydrofluoric acid.

Further, a dry etching method was performed using an SiO ₂ film having an opening pattern as an etching mask. In the dry etching, the element is separated by etching by ICP method at a substrate temperature of 100 ° C, an ICP output of 300 W, a bias voltage of 20 W, a chlorine gas of 3 sccm, and a pressure of 0.3 Pa, thereby removing the light-emitting portion and exposing the window layer and the supporting substrate. Removal section.

Thereafter, in the same manner as in Example 1, a step from the formation of the second ohmic electrode to the second surface roughening treatment was performed to produce a light-emitting element. The roughness of the surface of the window layer and the support substrate and the rough surface of the side surface at this time were measured, and Ra = 0.5 μm.

The light-emitting element produced in the above procedure was produced in the same manner as in Example 1 to measure the light-emitting output. As a result, the light-emitting output was 62% higher than that of the comparative example described later. In addition, electrode peeling due to surface roughening did not occur.

<Comparative Example> The first surface roughening treatment and the second surface roughening treatment were not performed, and a light-emitting element was produced in the same manner as in Example 1 except that the first selective etching layer was not provided under the first ohmic electrode.

The light-emitting element produced in the above procedure was produced in the same manner as in Example 1 to measure the light-emitting output. As a result, although the peeling of the electrode did not occur, the light emission output was lower than that of the first embodiment and the second embodiment as described above.

Further, the present invention is not limited to the above-described embodiments, and the above-described embodiments are exemplified, and those having substantially the same technical concept as those described in the patent application scope of the present invention can be obtained by the same effects. It is within the technical scope of the present invention.

1‧‧‧Lighting elements
102‧‧‧Select etching layer
102A‧‧‧Second selective etching layer
102B‧‧‧First choice etching layer
103‧‧‧First semiconductor layer
104‧‧‧Active layer
105‧‧‧Second semiconductor layer
106‧‧‧buffer layer
107‧‧‧Window layer and support substrate
108‧‧‧Lighting Department
109‧‧‧ epitaxial substrate
110‧‧‧Light-emitting element substrate
121‧‧‧First ohmic electrode
122‧‧‧Second ohmic electrode
140‧‧‧Second ohmic electrode forming region
141‧‧‧cut area
150‧‧‧Insulation protective film
170‧‧‧Removal
180‧‧‧Non-removal department

[Fig. 1] is a schematic view showing an example of a light-emitting element of the present invention. [Fig. 2] A step diagram showing an example of a method of producing a light-emitting device of the present invention. [Fig. 3] is a schematic view showing an epitaxial substrate in which a selective etching layer, a light-emitting portion, and a window layer-supporting substrate are grown on a substrate during the manufacturing process of the method for producing a light-emitting device of the present invention. [Fig. 4] is a schematic view showing a light-emitting element substrate in which a substrate and a second selective etching layer are removed from an epitaxial substrate in the manufacturing process of the method for manufacturing a light-emitting device of the present invention. [Fig. 5] is a schematic view of a light-emitting element substrate on which a first ohmic electrode is formed in a process of manufacturing a light-emitting element of the present invention. [Fig. 6] is a schematic view of a light-emitting element substrate subjected to a first surface roughening process in the manufacturing process of the method for producing a light-emitting device of the present invention. [Fig. 7] is a schematic view of a light-emitting element substrate subjected to a component separation step in the manufacturing process of the method for producing a light-emitting device of the present invention. [Fig. 8] is a schematic view showing a second ohmic electrode and a light-emitting element substrate on which an insulating protective film is formed in the manufacturing process of the method for producing a light-emitting device of the present invention.

1‧‧‧Lighting elements

102B‧‧‧First choice etching layer

103‧‧‧First semiconductor layer

104‧‧‧Active layer

105‧‧‧Second semiconductor layer

106‧‧‧buffer layer

107‧‧‧Window layer and support substrate

108‧‧‧Lighting Department

121‧‧‧First ohmic electrode

122‧‧‧Second ohmic electrode

150‧‧‧Insulation protective film

170‧‧‧Removal

180‧‧‧Non-removal department

Claims (6)

A light-emitting element having a window layer and a supporting substrate and a light-emitting portion disposed on the window layer and the supporting substrate, the light-emitting portion sequentially including a second semiconductor layer of the second conductivity type, an active layer and a first a first semiconductor layer of a conductive type, wherein the light emitting element has a first ohmic electrode disposed on the first semiconductor layer via a first selective etch layer, and a surface of the first semiconductor layer and the light emitting portion At least a portion of the side surface is covered with an insulating protective film, and the surface of the first semiconductor layer and the surface of the window layer and the supporting substrate are surface roughened. The light-emitting element according to claim 1, wherein the light-emitting element has a removal portion excluding the light-emitting portion, a non-removed portion other than the removal portion, and the first semiconductor layer on the non-removed portion is transmitted through the first The first ohmic electrode provided to select the etching layer, and a second ohmic electrode having the window layer and the supporting substrate disposed on the removing portion. The light-emitting element according to claim 1 or 2, wherein the window layer and the supporting substrate are composed of any one of Gap, GaAsP, AlGaAs, Al ₂ O ₃ , SiO ₂ , and SiC, the first semiconductor layer, the first semiconductor layer The active layer and the second semiconductor layer are composed of AlGaInP or AlGaAs. A method for fabricating a light-emitting device, comprising: selecting an etching layer forming step, forming a selective etching layer on the substrate, the selective etching layer having at least a second selective etching layer and a first selective etching layer; and a light emitting portion forming step, Forming a light-emitting portion by sequentially growing a first semiconductor layer, an active layer, and a second semiconductor layer by epitaxial growth on the selective etching layer to form a light-emitting portion by epitaxial growth of the material; a layer-supporting substrate forming step is formed on the light-emitting portion to form a window layer and a supporting substrate by epitaxial growth of a material having an amorphous matching system for the substrate; and a residual step of removing the substrate and the first Selecting an etch layer and leaving only the first selective etch layer on the surface of the first semiconductor layer; the first ohmic electrode forming step is to form a first ohmic electrode on the surface of the first selective etch layer; An etching layer removing step of removing the first selective etching layer in a region other than a lower portion of the first ohmic electrode; a first surface roughening processing step of the first semiconductor layer The surface is subjected to a surface roughening treatment; the element separation step is a removal portion that removes a portion of the light-emitting portion and a non-removed portion other than the light-emitting portion; and the second ohmic electrode formation step is performed on the window layer and the support substrate from which the light-emitting portion is removed Forming a second ohmic electrode thereon; covering a surface of the first semiconductor layer and at least a portion of a side surface of the light emitting portion with an insulating protective film; and a second surface roughening step of roughening the window layer and supporting The surface and side of the substrate. The method of manufacturing a light-emitting device according to claim 4, wherein the substrate is GaAs or Ge, and the window layer and the supporting substrate are any one of Gap, GaAsP, AlGaAs, Al ₂ O ₃ , SiO ₂ , and SiC, and The first semiconductor layer, the active layer, and the second semiconductor layer are AlGaInP or AlGaAs. The method for producing a light-emitting device according to claim 5, wherein in the first surface roughening step, a mixture of an organic acid and a mineral acid is used, the organic acid comprising: citric acid, malonic acid, formic acid And at least one of acetic acid and tartaric acid, the inorganic acid comprising: at least one of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid; and in the second surface roughening step, using an organic acid and a mineral acid The organic acid includes at least one of citric acid, malonic acid, formic acid, acetic acid, and tartaric acid, and the inorganic acid includes at least one of hydrochloric acid, sulfuric acid, nitric acid, and hydrofluoric acid, and The mixture contains iodine.