JP6623973B2 - Light emitting device and method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a light emitting device made of a compound semiconductor and a method for manufacturing the same.

A light emitting element (LED) made of a compound semiconductor, for example, AlGaInP has an SiO ₂ protective film formed thereon to prevent deterioration or leakage due to humidity or foreign matter adhesion during a process (for example, see Patent Document 1).

In particular, the SiO ₂ film used for protecting the side surface of the light emitting layer is preferably formed of a material and a reaction system having a high shape following property, and is formed by plasma CVD using TEOS and oxygen. As a result, the side surface of the light emitting layer can be satisfactorily covered, and can sufficiently fulfill the function as a protective film.

JP 2007-266646 A

On the other hand, since the above-mentioned SiO ₂ film has a high shape-following property, it also uniformly covers a roughened surface as a light extraction surface, and thus has an effect of reducing unevenness (Rz). By reducing the irregularities on the surface of the SiO ₂ film, the anchor effect at the time of coating with the resin is reduced, the adhesiveness of the resin is reduced, and when the resin is sealed, the resin is peeled off in a high-humidity environment with the existing technology. There was a problem that occurs.

  The present invention has been made in view of the above-described problems, and a light-emitting element that can suppress occurrence of resin peeling in a high-humidity environment when resin sealing is performed without reducing resin adhesion. And a method for manufacturing a light-emitting element.

In order to achieve the above object, the present invention is a light-emitting element having a light-emitting portion made of a compound semiconductor, an electrode, and a protective film, and on a surface of the protective film covering at least a part of the light-emitting element, Provided is a light-emitting element in which unevenness is formed in which _Rz exceeds 5 nm.

As described above, since the surface of the protective film has irregularities with _Rz exceeding 5 nm, the anchor effect when the resin is coated is increased, the resin adhesion is increased, and the resin sealing is performed. The occurrence of resin peeling can be suppressed.

At this time, the protective film is preferably made of SiO ₂ .

SiO ₂ can be suitably used as the protective film.

  At this time, it is preferable that at least a part of the surface of the light emitting unit is roughened.

  With such a structure, the luminous efficiency of the light-emitting element can be improved.

Further, the present invention is a method for manufacturing a light-emitting element having a light-emitting portion made of a compound semiconductor, an electrode, and a protective film, wherein the protective film, which covers at least a part of the light-emitting element, is a SiO ₂ film. The present invention provides a method for manufacturing a light-emitting element, wherein irregularities are formed on the surface of the SiO ₂ film by performing a frost treatment with a liquid obtained by mixing hydrofluoric acid and a monovalent to tetravalent inorganic acid or organic acid. .

With such a method, it is possible to relatively easily form irregularities on the surface of the SiO ₂ film, increase the resin adhesion, and suppress the occurrence of resin peeling when performing resin sealing. A device can be manufactured.

  At this time, at least one of sulfuric acid, hydrochloric acid, and phosphoric acid is used as the inorganic acid, and at least one of malonic acid, acetic acid, citric acid, tartaric acid, and malic acid is used as the organic acid. Preferably, it is used.

If the above-mentioned inorganic or organic acid is used, irregularities can be more reliably formed on the surface of the SiO ₂ film.

  As described above, according to the light emitting element of the present invention, it is possible to increase the resin adhesion and suppress the occurrence of resin peeling when performing resin sealing. Further, by using the method for manufacturing a light emitting element of the present invention, a light emitting element capable of increasing resin adhesion and suppressing occurrence of resin peeling when performing resin sealing can be manufactured relatively easily. .

FIG. 1 is a schematic sectional view illustrating a first embodiment of a light emitting device of the present invention. FIG. 4 is a schematic sectional view showing a second embodiment of the light emitting device of the present invention. FIG. 6 is a schematic sectional view showing a third embodiment of the light emitting device of the present invention. It is a schematic sectional view showing a 4th embodiment of the light emitting element of the present invention. FIG. 4 is a process cross-sectional view illustrating a first embodiment of a method for manufacturing a light emitting device of the present invention. FIG. 6 is a process cross-sectional view (continued from FIG. 5) showing the first embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 7 is a process cross-sectional view (continued from FIG. 6) illustrating the first embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 8 is a process cross-sectional view (continued from FIG. 7) illustrating the first embodiment of the method for manufacturing a light-emitting element of the present invention. It is a process sectional view showing a 2nd embodiment of the manufacturing method of the light emitting element of the present invention. FIG. 10 is a process cross-sectional view (continued from FIG. 9) showing the second embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 11 is a process cross-sectional view (continued from FIG. 10) showing the second embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 12 is a process cross-sectional view (continued from FIG. 11) showing the second embodiment of the method for manufacturing a light-emitting element of the present invention. It is a process sectional view showing a 3rd embodiment of the manufacturing method of the light emitting element of the present invention. FIG. 14 is a process cross-sectional view (continued from FIG. 13) showing the third embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 15 is a process cross-sectional view (continued from FIG. 14) illustrating the third embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 16 is a process cross-sectional view (continued from FIG. 15) showing the third embodiment of the method for manufacturing a light-emitting element of the present invention. FIG. 17 is a process cross-sectional view (continued from FIG. 16) showing the third embodiment of the method for manufacturing a light-emitting element of the present invention. It is process sectional drawing which shows 4th Embodiment of the manufacturing method of the light emitting element of this invention. FIG. 19 is a process cross-sectional view (continued from FIG. 18) illustrating the fourth embodiment of the method for manufacturing the light-emitting element of the present invention. FIG. 20 is a process cross-sectional view (continued from FIG. 19) illustrating the fourth embodiment of the method for manufacturing the light-emitting element of the present invention. FIG. 21 is a process cross-sectional view (continued from FIG. 20) showing the fourth embodiment of the method for manufacturing a light-emitting element of the present invention. It is a figure which shows the relationship between a frost processing condition and a resin peeling rate. FIG. 4 is a schematic cross-sectional view illustrating a light emitting device of Comparative Example 1. FIG. 9 is a schematic cross-sectional view illustrating a light emitting device of Comparative Example 2. FIG. 9 is a schematic sectional view showing a light emitting device of Comparative Example 3. 13 is a schematic sectional view illustrating a light emitting device of Comparative Example 4. FIG.

As described above, the SiO ₂ film used for protecting the side surface of the light emitting layer is a material having a high shape following property, and is preferably formed by plasma CVD using a reaction between TEOS and oxygen. On the other hand, since the above-mentioned SiO ₂ film has a high shape following property, it also uniformly covers the roughened surface as the light extraction surface, so that the unevenness of the surface of the SiO ₂ film is reduced. For this reason, the anchor effect at the time of resin coating became small, the resin adhesiveness was reduced, and when resin sealing was performed, there existed a problem that resin peeling occurred in the existing technology.

The present inventors diligently studied a light emitting element that can suppress occurrence of resin peeling when resin sealing is performed without reducing resin adhesion. As a result, since the surface of the SiO ₂ film has irregularities with _Rz exceeding 5 nm, the anchor effect at the time of coating with the resin is increased, the resin adhesion is increased, and the resin sealing is performed. It has been found that the occurrence of resin peeling can be suppressed, and the present invention has been completed. Note that _Rz in the present application indicates the ten-point average roughness of the surface (JIS B0601-1994).

  Hereinafter, the present invention will be described in detail with reference to the drawings as an example of an embodiment, but the present invention is not limited to this.

(First embodiment)
First, a light emitting device according to a first embodiment of the present invention will be described with reference to FIG.
FIG. 1 shows a light emitting device 10 according to a first embodiment of the present invention.
The light emitting element 10 includes a support substrate 130 having a second electrode 162 and a second bonding metal layer 131, and an interface SiO ₂ part 120 having a conductive part 121 on a part of the surface of the first bonding metal layer 122. A second conductivity type current propagation layer 107 (thickness: 0.5 to 5.0 μm), a second conductivity type buffer layer 106 for alleviating lattice mismatch with the current propagation layer 107, and a second conductivity type second The semiconductor layer 105 (thickness: 0.5 to 1.0 μm), the active layer 104 (thickness: 0.1 to 1.0 μm), the first conductivity type first semiconductor layer 103 (thickness: 0.5 to 1.0 μm) ) Is laminated, a first electrode 161 is formed thereon, and a substrate having an SiO ₂ film 170 formed on the surface of the semiconductor layer is bonded to the light emitting element, and the surface of the SiO ₂ film 170 has an _Rz of 5 nm. Are formed. Here, Rz of the formed unevenness is preferably 50 nm or more, more preferably 100 nm or more.
Since the surface of the SiO ₂ film 170 has irregularities with _Rz exceeding 5 nm, the anchor effect at the time of coating with the resin is increased, the resin adhesion is increased, and the resin sealing is performed. In this case, occurrence of resin peeling can be suppressed.

Incidentally, the first conductivity type first semiconductor layer 103, the active layer 104, second conductive type second semiconductor layer 105, the material of the second conductivity type buffer layer 106 _{(Al x Ga 1-x)} y In 1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) or Al _z Ga _1−z As (0 ≦ z ≦ 1). The current spreader layer 107 may be _{Al z Ga 1-z As (} 0 ≦ z ≦ 1) or _{GaAs w P 1-w (0} ≦ w ≦ 1). Further, for example, the first semiconductor layer 103 is formed of two or more types of Al composition layers, and a layer (second layer) 103B on the side near the active layer 104 and an Al composition on the side near the first electrode 161. A structure having a low layer (first layer) 103A can be employed (see FIG. 1). The second layer 103B is a functional layer having a function of a clad layer, and does not mean a single composition or a single condition layer.

  Here, it is preferable that at least a part of the surface of the light emitting unit 108 (that is, a part of the surface of the first semiconductor layer 103) is roughened. With such a structure, the luminous efficiency of the light-emitting element can be improved.

  Next, a method for manufacturing the light emitting device according to the first embodiment will be described with reference to FIGS.

  As shown in FIG. 5, a substrate (starting substrate) 101 whose crystal axis is inclined in the [110] direction from the [001] direction is prepared (GaAs or Ge can be suitably used as the substrate 101). If the substrate 101 is selected from the above materials, the material of the active layer 104 can be epitaxially grown in a lattice-matched system, so that the quality of the active layer can be easily improved, and the brightness and the life characteristics can be improved.

  Next, on the starting substrate 101, a first semiconductor layer 103 of the first conductivity type, an active layer 104, a second semiconductor layer 105 of the second conductivity type, and a current propagation layer 107 having substantially the same lattice constant as the substrate are formed by epitaxial growth. Form sequentially. Further, a selective etching layer 102 for removing the substrate is inserted between the starting substrate 101 and the first semiconductor layer 103. The selective etching layer 102 has a layer structure of two or more layers, and the layer 102A and the layer 102B having at least the layer 102A in contact with the starting substrate 101 and the layer 102B in contact with the first semiconductor layer 103 may be made of different materials or compositions. .

  More specifically, the first semiconductor layer 103 of the first conductivity type is formed on the starting substrate 101 by, for example, MOVPE (metal organic chemical vapor deposition), MBE (molecular beam epitaxy), or CBE (actinic beam epitaxy). An epitaxial substrate 109 is formed by epitaxially growing a buffer layer 106 and a current propagation layer 107 in this order on a light emitting portion 108 composed of an active layer 104 and a second semiconductor layer 105 of the second conductivity type.

Active layer 104 in accordance with the emission wavelength _{(Al x Ga 1-x)} y In 1-y P (0 ≦ x ≦ 1,0.4 ≦ y ≦ 0.6) or _{Al z Ga 1-z As (} 0 ≦ z ≦ 0.45). When applied to visible light illumination, it is preferable to select AlGaInP, and when applied to infrared illumination, it is preferable to select AlGaAs or InGaAs. However, the design of the active layer is not limited to the above materials because the wavelength can be adjusted to a wavelength other than the wavelength due to the material composition by using a superlattice or the like.

  For the first semiconductor layer 103 and the second semiconductor layer 105, AlGaInP or AlGaAs is selected, and the selection is not necessarily made of the same material system as the active layer 104.

  Note that the first semiconductor layer 103, the active layer 104, or the second semiconductor layer 105 generally includes a plurality of layers in each layer in order to improve characteristics. The two semiconductor layers 105 are not limited to a single layer.

  As the current propagation layer 107, AlGaAs, GaAsP, or GaP can be preferably used.

When the current propagation layer 107 is formed of GaAs _x P _1-x (0 ≦ x <1), the buffer layer 106 is most preferably formed of InGaP or AlInP. Since a lattice mismatch exists between GaAs _x P _1-x (x ≠ 1) and an AlGaInP-based material or AlGaAs-based material, GaAs _x P _1-x (x ≠ 1) has a high density of strain or Threading dislocations enter. The threading dislocation density can be adjusted by the composition x.

Next, as shown in FIG. 6, an interface SiO ₂ part 120 is deposited on at least a part of the current propagation layer 107 on the epitaxial substrate 109, and an interface metal part (conductive material) is formed on at least a part of the region having no interface SiO ₂ part. 1), a first bonding metal layer 122 covering at least a part of the interface SiO ₂ portion 120 and the interface metal portion 121 is provided, and a first laminate 123 is formed.

  Next, the second bonding metal layer 131 is provided on the permanent substrate (supporting substrate) 130 to form the second stacked body 132. A bonding substrate in which at least a part of the first bonding metal layer 122 and the second bonding metal layer 131 are in contact with each other, and the first stacked body 123 and the second stacked body 132 are bonded by applying a pressure of 1000 N and applying heat of 150 ° C. or more. 140 is formed.

  Next, as shown in FIG. 7, the starting substrate 101 is removed from the bonding substrate 140 by a wet etching method, so that the first semiconductor layer 103 is exposed. At the time of etching, etching is performed using a mixed solution of ammonia and hydrogen peroxide solution (the ratio of the hydrogen peroxide solution is twice or more the ammonia ratio). When the etching stop layer 102A is made of a material different from that of the starting substrate 101, etching using a mixed solution of ammonia and hydrogen peroxide can be selectively stopped. AlInP can be used as the etching stop layer 102A.

  After removing the starting substrate 101, the etching stop layer 102A is removed. When AlInP is used as the etching stop layer 102A, hydrochloric acid can be used for removal. GaAs can be used for the etching stop layer 102B to stop etching by hydrochloric acid.

  Next, a first electrode 161 in contact with the first semiconductor layer 103 is formed, a second electrode 162 in contact with the permanent substrate 130 is formed, and an insulating layer 170 covering at least a part of the first semiconductor layer 103 is formed. The light emitting element substrate 171 is manufactured.

  When the first conductivity type is n-type, the first electrode 161 contains at least one material of Au, Ag, Al, Ni, Pd, Ge, Si, and Sn and has a thickness of 100 nm or more. It can be. When the first conductivity type is p-type, the first conductivity type may include at least one material of Au, Be, Mg, and Zn, and have a thickness of 100 nm or more. When the second conductivity type is n-type, the second electrode 162 includes at least one material of Au, Ag, Al, Ni, Pd, Ge, Si, and Sn, and has a thickness of 100 nm or more. It can be. When the second conductivity type is a p-type, the second conductivity type may include at least one material of Au, Be, Mg, and Zn and have a thickness of 100 nm or more.

  Next, as shown in FIG. 8, a frost treatment is performed on the insulating layer 170 of the light emitting element substrate 171 using a liquid mixture of hydrofluoric acid and a monovalent to tetravalent inorganic or organic acid. Here, the inorganic acid is at least one of sulfuric acid, hydrochloric acid, and phosphoric acid, and the organic acid is at least one of malonic acid, acetic acid, citric acid, tartaric acid, and malic acid. In this manner, a frost processing substrate 180 having irregularities on the surface of the insulating layer 170 is manufactured. Next, the frost processing substrate 180 is separated into individual dies, a wire is provided on the first electrode 161, the second electrode 162 is fixed to the stem with a conductive resin, and then sealed with an epoxy resin to manufacture a light emitting diode.

(Second embodiment)
Next, a light emitting device according to a second embodiment of the present invention will be described with reference to FIG.
FIG. 2 shows a light emitting device 20 according to a second embodiment of the present invention.
The light emitting device 20 includes a support substrate 230 having a second electrode 262 and a second bonding metal layer 231, an interface transparent conductive film layer 220 having a contact portion 208 on the first bonding metal layer 222, and a second conductive metal layer 220 thereon. Type current propagation layer 207 (0.5 to 5.0 μm in thickness), second conductivity type buffer layer 206 for relaxing lattice mismatch with current propagation layer 207, and second conductivity type second semiconductor layer 205 (thickness of 0.5 to 5.0 μm). 5 to 1.0 μm), an active layer 204 (thickness layer 0.1 to 1.0 μm), and a first conductivity type first semiconductor layer 203 (thickness 0.5 to 1.0 μm). A light-emitting element in which a first electrode 261 is formed and a substrate on which a SiO ₂ film 270 is formed on the surface of a semiconductor layer is bonded, and the surface of the SiO ₂ film 270 has irregularities in which _Rz exceeds 5 nm. . Here, Rz of the formed unevenness is preferably 50 nm or more, more preferably 100 nm or more. Also in the second embodiment, since the surface of the SiO ₂ film 270 is formed with irregularities with _Rz exceeding 5 nm, the anchor effect when the resin is coated is increased as in the first embodiment, It is possible to increase the resin adhesion and suppress the occurrence of resin peeling when performing resin sealing.

Incidentally, the first conductivity type first semiconductor layer 203, the active layer 204, second conductive type second semiconductor layer 205, the material of the second conductivity type buffer layer 206 _{(Al x Ga 1-x)} y In 1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) or Al _z Ga _1−z As (0 ≦ z ≦ 1). The current spreader layer 207 may be _{Al z Ga 1-z As (} 0 ≦ z ≦ 1) or _{GaAs w P 1-w (0} ≦ w ≦ 1). Further, for example, the first semiconductor layer 203 is composed of two or more types of Al composition layers, and a layer (second layer) 203B near the active layer 204 and an Al composition layer near the first electrode 261 are provided. A configuration having a low layer (first layer) 203A can be employed (see FIG. 2). The second layer 203B is a functional layer having the function of a cladding layer, and does not mean a single composition or a single condition layer.
The interface transparent conductive film 220 is made of an oxide containing at least one of Mg, Ni, Cu, Ga, In, and Sn.

  Next, a method for manufacturing the light emitting element 20 according to the second embodiment will be described with reference to FIGS.

  As shown in FIG. 9, a substrate (starting substrate) 201 whose crystal axis is tilted in the [110] direction from the [001] direction is prepared (GaAs or Ge can be suitably used as the substrate 201).

  Next, on the starting substrate 201, the first semiconductor layer 203 of the first conductivity type, the active layer 204, the second semiconductor layer 205 of the second conductivity type, the current propagation layer 207, the contact layer 208 are sequentially formed by epitaxial growth, and an epitaxial substrate 210 is formed. Note that the first semiconductor layer 203, the active layer 204, and the second semiconductor layer 205 form a light emitting unit 209. Further, a selective etching layer 202 for removing the substrate is inserted between the starting substrate 201 and the first semiconductor layer 203. The selective etching layer has a layer structure of two or more layers, and has at least a layer 202A in contact with the starting substrate and a layer 202B in contact with the first semiconductor layer. The layer 202A and the layer 202B may be made of different materials or compositions.

  The first semiconductor layer 203, the active layer 204, the second semiconductor layer 205, and the current propagation layer 207 are the same as the first semiconductor layer 103, the active layer 104, the second semiconductor layer 105, and the current propagation layer 107 of the first embodiment. Can be used, and a similar structure can be obtained. The contact layer 208 may be made of the same material as the current propagation layer 207, or may be made of a different material.

  Next, as shown in FIG. 10, a part of the contact layer 208 is removed from the epitaxial substrate 210, and a first transparent conductive film 220 is deposited so as to be in contact with at least a part of both the contact part 208 and the current propagation layer 207. Then, a first bonding metal layer 222 covering at least a part of the first transparent conductive film 220 is provided to form a first stacked body 223.

  Next, the second bonding metal layer 231 is provided on the permanent substrate (supporting substrate) 230 to form the second stacked body 232. A bonding substrate in which the first bonding metal layer 222 and at least a part of the second bonding metal layer 231 are in contact with each other, and the first stacked body 223 and the second stacked body 232 are bonded by applying a pressure of 1000 N and applying heat of 150 ° C. or more. Form 240.

  Next, as shown in FIG. 11, the starting substrate 201 is removed from the bonding substrate 240 by a wet etching method, so that the first semiconductor layer 203 is exposed. The etching can be performed in the same manner as in the first embodiment.

  After removing the starting substrate 201, the etching stop layer 202A is removed. The same materials as the etching stop layers 102A and 102B of the first embodiment can be used for the etching stop layers 202A and 202B.

  Next, a first electrode 261 in contact with the first semiconductor layer 203 is formed, a second electrode 262 in contact with the permanent substrate 230 is formed, and an insulating layer 270 covering at least a part of the first semiconductor layer 203 is formed. The light emitting element substrate 271 is manufactured. The first electrode 261 and the second electrode 262 can be made of the same material as the first electrode 161 and the second electrode 162 of the first embodiment, and can have the same thickness.

  Next, as shown in FIG. 12, a frost process is performed on the insulating layer 270 of the light emitting element substrate 271 in the same manner as in the first embodiment. Thus, a frost processing substrate 280 having irregularities on the surface of the insulating layer 270 is manufactured. Next, the frosted substrate 280 is separated into individual dice, wires are provided on the first electrode 261, the second electrode 262 is fixed to the stem with a conductive resin, and then a light emitting diode sealed with an epoxy resin is manufactured.

(Third embodiment)
Next, a light emitting device according to a third embodiment of the present invention will be described with reference to FIG.
FIG. 3 shows a light emitting device 30 according to a third embodiment of the present invention.
The light emitting element 30 includes a support substrate 330 having a second dielectric film 321 and a second adhesive layer 325, a first dielectric film 320 on the first adhesive layer 324, and a second conductivity type current propagation layer 307 thereon. (Thickness: 0.5 to 5.0 μm), a second conductivity type buffer layer 306 and a second conductivity type second semiconductor layer 305 (thickness: 0.5 to 1.0 μm) for alleviating lattice mismatch with the current propagation layer 307 ), An active layer 304 (thickness layer of 0.1 to 1.0 μm) and a first conductivity type first semiconductor layer 303 (thickness of 0.5 to 1.0 μm), and a first electrode 350 is formed thereon. In addition, a part of the semiconductor layer is cut out to the second conductivity type current propagation layer 307, a second electrode 351 is formed on the cut out second conductivity type current propagation layer 307, and the semiconductor layer surface to a light emitting element and the substrate SiO ₂ film 370 is formed is bonded, SiO ₂ Irregularities with _Rz exceeding 5 nm are formed on the surface of the film 370. Here, Rz of the formed unevenness is preferably 50 nm or more, more preferably 100 nm or more. Also in the third embodiment, since the surface of the SiO ₂ film 370 has irregularities with _Rz of more than 5 nm, the anchor effect when the resin is coated as in the first embodiment increases, It is possible to increase the resin adhesion and suppress the occurrence of resin peeling when performing resin sealing.

Incidentally, the first conductivity type first semiconductor layer 303, the active layer 304, second conductive type second semiconductor layer 305, the material of the second conductivity type buffer layer 306 _{(Al x Ga 1-x)} y In 1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) or Al _z Ga _1−z As (0 ≦ z ≦ 1). The current spreader layer 307 may be _{Al z Ga 1-z As (} 0 ≦ z ≦ 1) or _{GaAs w P 1-w (0} ≦ w ≦ 1). Further, for example, the first semiconductor layer 303 is formed of two or more types of Al composition layers, and a layer (second layer) 303 </ b> B on the side near the active layer 304 and an Al composition on the side near the first electrode 350. A structure having a low layer (first layer) 303A can be employed (see FIG. 3). The second layer 303B is a functional layer having the function of a cladding layer, and does not mean a single composition or a single condition layer.

  Next, a method for manufacturing the light emitting element 30 according to the third embodiment will be described with reference to FIGS.

  As shown in FIG. 13, a substrate (starting substrate) 301 whose crystal axis is inclined in the [110] direction from the [001] direction is prepared (GaAs or Ge can be suitably used as the substrate 301).

  Next, on the starting substrate 301, a first semiconductor layer 303 of the first conductivity type, an active layer 304, a second semiconductor layer 305 of the second conductivity type, and a current propagation layer 307 having substantially the same lattice constant as the substrate are epitaxially grown. An epitaxial substrate 309 is formed sequentially. Note that the first semiconductor layer 303, the active layer 304, and the second semiconductor layer 305 constitute a light emitting unit 308. Further, a selective etching layer 302 for removing the substrate is inserted between the starting substrate 301 and the first semiconductor layer 303. The selective etching layer 302 has a layer structure of two or more layers, and has at least a layer 302A in contact with the starting substrate and a layer 302B in contact with the first semiconductor layer. The layer 302A and the layer 302B may be made of different materials or compositions.

  The first semiconductor layer 303, the active layer 304, the second semiconductor layer 305, and the current propagation layer 307 are the same as the first semiconductor layer 103, the active layer 104, the second semiconductor layer 105, and the current propagation layer 107 of the first embodiment. Can be used, and a similar structure can be obtained.

Next, as shown in FIG. 14, a first SiO ₂ film 320 is deposited on the current propagation layer 307 of the epitaxial substrate 309. The first SiO ₂ film 320 can be formed by optical CVD, sputtering, or PECVD.

Next, a transparent adhesive layer 325 is formed on the first SiO ₂ film 320, and a first bonding substrate 326 is formed. For the transparent adhesive layer 325, BCB (benzocyclobutene), epoxy, or the like can be selected. It is preferable to select a material that can be formed by a dipping method or a spin coating method. For example, in the case of cycloten, which is a BCB material that can be deposited by spin coating, cycloten is dropped on the first SiO ₂ film 320, and spin coating is performed at a rotation speed of 1,000 to 5,000 rpm. Since it is only necessary to apply the adhesive uniformly, any of the above-mentioned rotation speeds can be selected, but a rotation speed of 3,000 rpm or more is preferable. After the spin coating, the solvent is volatilized by holding on a hot plate at 80 to 110 ° C. for 30 seconds or more. Any of the above-mentioned conditions can be selected since the solvent only needs to evaporate, but it is preferable to select a holding time of 90 ° C. or more and 60 seconds or more.

Next, a second SiO ₂ film 321 is deposited on the transparent substrate (supporting substrate) 330 to form a second bonding substrate 331. The second SiO ₂ film 321 can be formed by optical CVD, sputtering, or PECVD.

  Although the example in which the transparent bonding layer 325 is provided only on the first bonding substrate 326 has been disclosed, the same effect can be obtained by providing the second bonding substrate 331 with the transparent bonding layer. Further, a transparent adhesive layer can be provided on both the first bonding substrate 326 and the second bonding substrate 331.

Next, as shown in FIG. 14, the first bonding substrate 326 and the second bonding substrate 331 are set so that the transparent adhesive layer 325 and the second SiO ₂ film 321 face each other and do not contact each other, and a vacuum atmosphere of 30 Pa or less is provided. To After the vacuum atmosphere, the transparent adhesive layer 325 and the second SiO ₂ film 321 are brought into contact with each other, and the pressure is controlled to be 5000 N and the temperature is between 100 and 200 ° C., and the temperature is maintained for 5 minutes or more. Is applied, the first bonding substrate 326 and the second bonding substrate 331 are pressed to form a bonding substrate 340.

  The starting substrate 301 is removed from the bonding substrate 340 by etching. The etching can be performed in the same manner as in the first embodiment.

  After removing the starting substrate 301, the etching stop layer 302A is removed. The same materials as the etching stop layers 102A and 102B of the first embodiment can be used for the etching stop layers 302A and 302B.

  Next, as shown in FIG. 15, a first electrode 350 in contact with the first semiconductor layer 303 is formed. The first electrode 350 can be made of the same material as the first electrode 161 of the first embodiment, and can have a thickness of 300 nm or more. Next, a pattern in which the first semiconductor layer 303 and the active layer 304 in the region 360 other than the region where the first electrode 350 exists is cut out by etching using a dry method or a wet method. FIG. 15 shows an example in which the current propagation layer 307 is notched, but the same function is obtained even if the etching is stopped while the second semiconductor layer 305 or the buffer layer 306 is exposed. In FIG. 15, the region other than the region 360 is represented as a flat surface, but the invention is not limited to the flat surface, and the region other than the region 360 may be a rough surface or an uneven surface.

Next, as shown in FIG. 16, an insulating layer 370 covering at least a part of the first semiconductor layer 303 is formed. The insulating layer 370 is SiO ₂ . FIG. 16 illustrates an example in which the active layer 304, the second semiconductor layer 305, the buffer layer 306, and a part of the current propagation layer 307 are covered, but the embodiment is not limited to this.

  Next, a light-emitting element substrate 371 in which the second electrode 351 is formed in part of the region 360 is formed. The second electrode 351 can be made of the same material as the second electrode 162 of the first embodiment, and can have a thickness of 300 nm or more.

  Next, as shown in FIG. 17, a frost treatment is performed on the surface of the insulating layer 370 of the light emitting element substrate 371 in the same manner as in the first embodiment, and a frost treated substrate 380 having irregularities on the surface of the insulating layer 370 is obtained. Make it.

  Next, after the frosted substrate 380 is divided into individual dice by stealth dicing or blade dicing, the dice is fixed to the stem, wires are provided on the first electrode 350 and the second electrode 351, and sealed with epoxy resin. A stopped light emitting diode is manufactured.

(Fourth embodiment)
Next, a light emitting device according to a fourth embodiment of the present invention will be described with reference to FIG.
FIG. 4 shows a light emitting device 40 according to a fourth embodiment of the present invention.
The light emitting device 40 includes a second conductivity type current propagation layer 407 (thickness of 30 to 150 μm), a second conductivity type buffer layer 406 for reducing lattice mismatch with the current propagation layer 407, and a second conductivity type second semiconductor layer 405. (Thickness of 0.5 to 1.0 μm), active layer 404 (thickness of 0.1 to 1.0 μm), and first conductive type first semiconductor layer 403 (thickness of 0.5 to 1.0 μm) The first electrode 450 is formed thereon, and a part of the semiconductor layer is cut out to the second conductivity type current propagation layer 407. second electrode 451 is formed, further a light-emitting element SiO ₂ film 470 is formed on the semiconductor layer surface, _{unevenness R z} on the surface of the SiO ₂ film 470 is more than 5nm is formed. Here, Rz of the formed unevenness is preferably 50 nm or more, more preferably 100 nm or more. Also in the fourth embodiment, since the surface of the SiO ₂ film 470 has the irregularities with _Rz exceeding 5 nm, the anchor effect when the resin is coated is increased as in the first embodiment, It is possible to increase the resin adhesion and suppress the occurrence of resin peeling when performing resin sealing.

Incidentally, the first conductivity type first semiconductor layer 403, the active layer 404, second conductive type second semiconductor layer 405, the material of the second conductivity type buffer layer 406 _{(Al x Ga 1-x)} y In 1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) or Al _z Ga _1−z As (0 ≦ z ≦ 1). The current spreader layer 407 may be _{Al z Ga 1-z As (} 0 ≦ z ≦ 1) or _{GaAs w P 1-w (0} ≦ w ≦ 1). In addition, for example, the first semiconductor layer 403 is formed of two or more types of Al compositions, and a layer (second layer) 403 </ b> B near the active layer 404 and an Al composition near the first electrode 450 are provided. A structure having a low layer (first layer) 403A can be employed (see FIG. 4). The second layer 403B is a functional layer having the function of a cladding layer, and does not mean a single composition or a single condition layer.

  Next, a method for manufacturing the light emitting element 40 according to the fourth embodiment will be described with reference to FIGS.

  As shown in FIG. 18, a substrate (starting substrate) 401 whose crystal axis is inclined in the [110] direction from the [001] direction is prepared (GaAs or Ge can be suitably used as the substrate 401).

  Next, on the starting substrate 401, the first semiconductor layer 403 of the first conductivity type, the active layer 404, the second semiconductor layer 405 of the second conductivity type, and the current propagation layer 407, which have substantially the same lattice constant as the substrate, are epitaxially grown. An epitaxial substrate 409 is formed sequentially. Note that the first semiconductor layer 403, the active layer 404, and the second semiconductor layer 405 constitute a light emitting unit 408. Further, a selective etching layer 402 for removing the substrate is inserted between the starting substrate 401 and the first semiconductor layer 403. The selective etching layer has a layer structure of two or more layers, and has at least a layer 402A in contact with the starting substrate and a layer 402B in contact with the first semiconductor layer. The layer 402A and the layer 402B may be formed using different materials or compositions.

The first semiconductor layer 403, the active layer 404, the second semiconductor layer 405, and the current propagation layer 407 are the same as the first semiconductor layer 103, the active layer 104, the second semiconductor layer 105, and the current propagation layer 107 of the first embodiment. Can be used, and a similar structure can be obtained.
The first semiconductor layer 403 is composed of two or more types of Al compositions, and a layer (second layer) 403B near the active layer 404 and a low Al composition layer (close to the starting substrate 401). (First layer) 403A. The layer 403B is a functional layer having the function of a clad layer, and does not mean a single composition or a single condition layer.

  Next, as shown in FIG. 19, the starting substrate 401 is removed by etching. The etching can be performed in the same manner as in the first embodiment.

  After removing the starting substrate 401, the etching stop layer 402A is removed. The same material as the etching stop layers 102A and 102B of the first embodiment can be used for the etching stop layers 402A and 402B.

  Next, a pattern in which the region 460 of the first semiconductor layer 403 and the active layer 404 is cut out is formed by etching by a dry method or a wet method. Although FIG. 19 shows an example in which the current propagation layer 407 is cut away, the same function can be obtained even if the etching is stopped in a state where the second semiconductor layer 405 or the buffer layer 406 is exposed. In the example of FIG. 19, the region other than the region 460 is represented as a flat surface, but is not limited to the flat surface, and the region other than the region 460 may be a rough surface or an uneven surface.

Next, as shown in FIG. 20, the first electrode 450 in contact with at least a part of the first semiconductor layer 403, at least a part of the region 460, and an insulating layer covering at least a part of the region other than the region 460. A layer 470 is formed. The insulating layer 470 is SiO ₂ . Then, a light-emitting element substrate 471 in which the second electrode 451 is formed in part of the region 460 is formed.

  The first electrode 450 can be made of the same material as the first electrode 161 of the first embodiment, and can have a thickness of 300 nm or more. The second electrode 451 can be made of the same material as the second electrode 162 of the first embodiment, and can have a thickness of 300 nm or more.

  Next, as shown in FIG. 21, a frost treatment is performed on the surface of the insulating layer 470 of the light emitting element substrate 471 in the same manner as in the first embodiment, and a frosted substrate 480 having irregularities on the surface of the insulating layer 470 is provided. Is prepared.

  Next, after dividing into individual dice by a stealth dicing method, a scribe method, a blade dicing method, or the like, the dice is fixed to the stem, wires are provided on the first electrode 450 and the second electrode 451, and light emission sealed with epoxy resin is performed. Make a diode.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

(Example 1)
A light emitting device 10 as shown in FIG. 1 was manufactured. The first semiconductor layer 103, the active layer 104, and the second semiconductor layer 105 of the light emitting device 10 were made of the same material, AlInGaP. The first semiconductor layer 103 is formed of two or more types of Al compositions, and a layer (second layer) 103 </ b> B near the active layer 104 and a low Al composition layer near the first electrode 161. (First layer) 103A. The second layer 103B is a functional layer having the function of a cladding layer. The first conductivity type was n-type, and the electrode material of the first electrode 161 was selected from an AuGeNi alloy, and the film thickness was 500 nm. The second conductivity type was p-type, and the electrode material of the second electrode 162 was selected from an AuBe alloy, and the film thickness was 500 nm. As the insulating layer 170, a SiO ₂ film was formed by a P-CVD method using TEOS and O ₂ as raw materials. The thickness was 300 nm.

This light emitting device was manufactured from eight wafers in which irregularities were formed on the surface of the SiO ₂ film 170 by frost processing on the epitaxial substrate under the conditions 1 to 8 shown in Table 1 in the manufacturing process. Table 1 shows the respective frost treatment conditions (acetic acid as a monovalent organic acid, malic acid as a trivalent organic acid, tartaric acid as a tetravalent organic acid, and citric acid as a tetravalent organic acid. The surface roughness (Rz) in the case of frost treatment with a solution obtained by mixing any of them with hydrofluoric acid or buffered hydrofluoric acid is also shown.

  With respect to the light emitting device manufactured as described above, the resin peeling rate under each frost treatment condition was examined. The result is shown in FIG.

(Example 2)
The light emitting device 20 as shown in FIG. 2 was manufactured. The first semiconductor layer 203, the active layer 204, and the second semiconductor layer 205 of this light emitting element were made of the same material, AlInGaP. The first semiconductor layer 203 is formed of two or more types of Al composition layers, and a layer (second layer) 203B near the active layer 204 and a low Al composition layer near the first electrode 261. (First layer) The structure had 203A. The layer 203B is a functional layer having a function of a cladding layer. The first conductivity type was n-type, and the electrode material of the first electrode 261 was selected from an AuGeNi alloy, and the film thickness was 500 nm. The second conductive type was p-type, and the electrode material of the second electrode 262 was selected from an AuBe alloy, and the film thickness was 500 nm. As the insulating layer 270, a SiO ₂ film was formed by a P-CVD method using TEOS and O ₂ as raw materials. The thickness was 300 nm.
This light-emitting element was manufactured from eight wafers in which irregularities were formed on the surface of the SiO ₂ film 270 by frost processing on the epitaxial substrate under the conditions 1 to 8 shown in Table 1 in the manufacturing process.

  With respect to the light emitting device manufactured as described above, the resin peeling rate under each frost treatment condition was examined. The result is shown in FIG.

(Example 3)
A light emitting device 30 as shown in FIG. 3 was manufactured. The first semiconductor layer 303, the active layer 304, and the second semiconductor layer 305 of this light emitting element were made of the same material, AlInGaP. The first semiconductor layer 303 is composed of two or more types of Al compositions, and a layer (second layer) 303 </ b> B near the active layer 304 and a layer with a low Al composition near the first electrode 350. (First layer) The structure having 303A was adopted. The layer 303B is a functional layer having a function of a cladding layer. The transparent adhesive layer 325 was cycloten, which is a BCB material that can be deposited by spin coating. Cycloten was dropped on the first SiO ₂ film 320, and spin coating was performed at a rotation speed of 3,000 rpm. After spin coating, the solvent was volatilized by holding on a hot plate at 90 ° C. for 60 seconds or more. The first conductivity type was n-type, and the electrode material of the first electrode 350 was selected from an AuGeNi alloy, and the film thickness was 500 nm. The second conductivity type was p-type, and the electrode material of the second electrode 351 was selected from an AuBe alloy, and the film thickness was 500 nm. As the insulating layer 370, a SiO ₂ film was formed by a P-CVD method using TEOS and O ₂ as raw materials. The thickness was 300 nm.
This light-emitting element was manufactured from eight wafers in which irregularities were formed on the surface of the SiO ₂ film 370 by frost processing on the epitaxial substrate under the conditions 1 to 8 shown in Table 1 in the manufacturing process.

  With respect to the light emitting device manufactured as described above, the resin peeling rate under each frost treatment condition was examined. The result is shown in FIG.

(Example 4)
A light emitting device 40 as shown in FIG. 4 was manufactured. The first semiconductor layer 403, the active layer 404, and the second semiconductor layer 405 of this light emitting element were made of the same material, AlInGaP. The first semiconductor layer 403 is formed of two or more types of Al compositions, and a layer (second layer) 403B near the active layer 404 and a layer having a low Al composition near the first electrode 450 are provided. (1st layer) It was set as the structure which has 403A. The layer 403B is a functional layer having a function of a cladding layer. The first conductivity type was n-type, and the electrode material of the first electrode 450 was selected from an AuGeNi alloy, and the film thickness was 500 nm. The second conductivity type was p-type, and the electrode material of the second electrode 451 was selected from an AuBe alloy, and the film thickness was 500 nm. As the insulating layer 470, a SiO ₂ film was formed by a P-CVD method using TEOS and O ₂ as raw materials. The thickness was 300 nm.
This light emitting element was manufactured from eight wafers in which irregularities were formed on the surface of the SiO ₂ film 470 by frost processing on the epitaxial substrate under the conditions 1 to 8 shown in Table 1 during the manufacturing process.

  With respect to the light emitting device manufactured as described above, the resin peeling rate under each frost processing condition was examined. The result is shown in FIG.

(Comparative Example 1)
A light emitting device 50 as shown in FIG. 23 was manufactured. This light emitting device has the same structure as that of the first embodiment except that frost processing is not performed on the surface of the SiO ₂ protective film 170. This light-emitting element was manufactured from one epitaxial wafer that was not subjected to frost processing.

  With respect to the light emitting device manufactured as described above, the resin peeling ratio was examined. The result is shown in FIG.

(Comparative Example 2)
The light emitting element 60 as shown in FIG. 24 was manufactured. This light emitting element has the same structure as that of the second embodiment except that frost processing is not performed on the surface of the SiO ₂ protective film 270. This light-emitting element was manufactured from one epitaxial wafer that was not subjected to frost processing.

  With respect to the light emitting device manufactured as described above, the resin peeling ratio was examined. The result is shown in FIG.

(Comparative Example 3)
A light emitting device 70 as shown in FIG. 25 was manufactured. This light emitting element has the same structure as that of the third embodiment except that frost processing is not performed on the surface of the SiO ₂ protective film 370. This light-emitting element was manufactured from one epitaxial wafer that was not subjected to frost processing.

  With respect to the light emitting device manufactured as described above, the resin peeling ratio was examined. The result is shown in FIG.

(Comparative Example 4)
A light emitting device 80 as shown in FIG. 26 was manufactured. This light emitting element has the same structure as that of the fourth embodiment except that frost processing is not performed on the SiO ₂ protective film 470. This light-emitting element was manufactured from one epitaxial wafer that was not subjected to frost processing.

  With respect to the light emitting device manufactured as described above, the resin peeling ratio was examined. The result is shown in FIG.

As shown in FIG. 22, the peeling rate of Example 1 in which the frost processing was performed was significantly improved as compared with Comparative Example 1 in which the frost processing was not performed under any of the frost processing conditions of the conditions 1 to 8. I understand.
Further, as shown in FIG. 22, the peeling rate of Example 2 in which the frost treatment was performed was significantly larger than that of Comparative Example 2 in which the frost treatment was not performed under any of the conditions 1 to 8 for the frost treatment. You can see the improvement.
Further, as shown in FIG. 22, the peeling rate of Example 3 in which the frost processing was performed was significantly higher than that of Comparative Example 3 in which the frost processing was not performed, regardless of the frost processing conditions of any of the conditions 1 to 8. You can see the improvement.
Further, as shown in FIG. 22, the peeling rate of Example 4 in which the frost processing was performed was significantly larger than that of Comparative Example 4 in which the frost processing was not performed, regardless of the frost processing conditions of any of the conditions 1 to 8. You can see the improvement.

  Note that the present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

10, 20, 30, 40, 50, 60, 70, 80 ... light-emitting elements,
101: starting substrate (substrate), 102: selective etching layer,
102A, 102B: etching stop layer, 103: first semiconductor layer,
103A: Layer on the starting substrate (first electrode) side 103B: Layer on the active layer side
104 ... active layer, 105 ... second semiconductor layer, 106 ... buffer layer,
107: current propagation layer, 108: light emitting section, 109: epitaxial substrate,
120: interface SiO ₂ part; 121: conductive part (interface metal part);
122: first bonding metal layer, 123: first laminate, 130: support substrate (permanent substrate),
131: second bonding metal layer, 132: second laminate, 140: bonding substrate,
161, a first electrode, 162, a second electrode, 170, a SiO ₂ film (insulating layer),
171, a light emitting element substrate; 180, a frost processing substrate;
201: starting substrate (substrate), 202: selective etching layer,
202A, 202B ... etching stop layer, 203 ... first semiconductor layer,
203A: layer on the starting substrate (first electrode) side; 203B: layer on the active layer side;
204: an active layer; 205: a second semiconductor layer;
206: buffer layer, 207: current propagation layer, 208: contact part (contact layer),
209: light emitting unit, 210: epitaxial substrate, 220: interface transparent conductive film layer,
222: first bonding metal layer, 223: first laminate,
230: support substrate (permanent substrate), 231: second bonding metal layer, 232: second laminate,
240: bonding substrate, 261: first electrode, 262: second electrode,
270: surface SiO ₂ part (insulating layer) 271: light emitting element substrate
280: Frost treated substrate,
301: starting substrate (substrate), 302: selective etching layer,
302A, 302B ... etching stop layer, 303 ... first semiconductor layer,
303A: first layer, 303B: second layer,
304 ... active layer, 305 ... second semiconductor layer, 306 ... buffer layer,
307: current propagation layer, 308: light emitting section, 309: epitaxial substrate,
320: first dielectric film (first SiO ₂ film);
321, a second dielectric film (second SiO ₂ film), 324, a first adhesive layer,
325: second adhesive layer (transparent adhesive layer) 326: first bonding substrate
330: support substrate (transparent substrate), 331: second bonding substrate, 340: bonding substrate 350: first electrode, 351: second electrode, 360: region,
370: SiO ₂ film (insulating layer) 371: Light emitting element substrate
380: Frost treated substrate,
401: starting substrate (substrate), 402: selective etching layer,
402A, 402B ... etching stop layer,
403 ... first semiconductor layer, 403A ... first layer, 403B ... second layer,
404: active layer, 405: second semiconductor layer,
406: buffer layer, 407: current propagation layer, 408: light emitting unit
409: epitaxial substrate, 450: first electrode, 451: second electrode,
460: region, 470: SiO ₂ film (insulating layer), 471: light emitting element substrate,
480 ... frosted substrate.

Claims (4)

A light-emitting element having a light- emitting portion made of a compound semiconductor, an electrode, and a protective film that directly covers a surface of the light-emitting portion ,
While at least a part of the surface of the light emitting section is roughened ,
The protection film covering at least a part of the light emitting element , wherein the surface of the protection film directly covering the surface of the light emitting portion has an irregularity with Rz exceeding 5 nm formed thereon. Light emitting element. The light emitting device of claim 1, wherein the protective film is a SiO _2. A method for manufacturing a light-emitting element having a light- emitting portion made of a compound semiconductor, an electrode, and a protective film that directly covers a surface of the light-emitting portion ,
While roughening at least a part of the surface of the light emitting section,
A the protective film covering at least a portion of the light emitting element, the SiO ₂ film wherein a protective film covering the surface of the light emitting portion directly, a hydrofluoric acid and a monovalent to tetravalent inorganic acid or an organic acid A method for manufacturing a light-emitting element, wherein irregularities are formed on the surface of the SiO ₂ film by performing frost treatment with a mixed solution. As the inorganic acid, at least one of sulfuric acid, hydrochloric acid, and phosphoric acid is used, and as the organic acid, at least one of malonic acid, acetic acid, citric acid, tartaric acid, and malic acid are used. The method for manufacturing a light emitting device according to claim 3 , wherein:

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