JP4951443B2 - Manufacturing method of light emitting diode - Google Patents

Description

  The present invention relates to a light emitting diode. In particular, the present invention relates to a light-emitting diode that is excellent in heat dissipation and can be easily divided when a chip is formed.

  Group III nitride semiconductors have a direct transition type band gap of energy corresponding to the range from visible light to ultraviolet light, and are excellent in luminous efficiency. Therefore, light emitting diodes (LEDs) and laser diodes (LDs) It is commercialized as a semiconductor light emitting device such as, and is used in various applications. Even when used in an electronic device, the group III nitride semiconductor has a potential for obtaining superior characteristics as compared with the case of using a conventional group III-V compound semiconductor.

  In general, a group III nitride semiconductor is manufactured by metal organic chemical vapor deposition (MOCVD) using trimethyl gallium, trimethyl aluminum, and ammonia as raw materials. The MOCVD method is a method in which a vapor of a raw material is contained in a carrier gas and transported to the substrate surface, and the raw material is decomposed by reaction with a heated substrate to grow crystals.

  As a substrate, it is known that a conductive substrate such as silicon carbide, silicon, zinc oxide, gallium arsenide, etc. can be used in addition to an insulating substrate such as sapphire, but perfectly lattice-matched with a group III nitride semiconductor. A substrate has not yet been developed, and at present, a blue LED element in which a group III nitride semiconductor layer is forcibly grown on sapphire having a lattice constant different by 10% or more has been put into practical use.

  A conventional blue LED element basically has a double hetero structure in which an n-type semiconductor layer made of a group III nitride semiconductor, a light emitting layer, and a p-type semiconductor layer are sequentially laminated on a sapphire substrate. As described above, since sapphire is insulative and the electrode cannot be taken out from the substrate side, a so-called face-up method in which a p-type electrode and an n-type ohmic electrode are provided on the same group III nitride semiconductor layer surface, Flip chip type elements.

  However, the conventional face-up type or flip-chip type device using sapphire as a substrate has a number of problems. First, since the p-type electrode and the n-type ohmic electrode are arranged in the horizontal direction, the current flows in the horizontal direction. As a result, there is a problem that the current density is locally increased and the chip generates heat. Next, since a very hard substrate called sapphire is used, there is a problem that advanced technology is required to form a chip. Finally, since sapphire has a relatively low thermal conductivity, it is a group III nitride. There is a problem that heat generated in the physical semiconductor layer cannot be efficiently radiated.

  In order to avoid the above problems, Patent Document 1 discloses a method of manufacturing a light emitting diode having an upper and lower electrode structure in which a group III nitride semiconductor layer is formed on a plating layer. That is, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer are sequentially stacked on a sapphire substrate to form a group III nitride semiconductor layer, and a p-type ohmic electrode is formed on one surface of the p-type semiconductor layer. First, a seed layer is formed on the p-type ohmic electrode, a resist is formed on the seed layer in a lattice pattern, a plating layer is formed so as to cover the seed layer and the resist, and then the sapphire substrate is removed. Discloses a method of manufacturing a light emitting diode having an upper and lower electrode structure in which an n-type ohmic electrode is formed on an n-type semiconductor layer and finally dicing is performed after removing the resist.

However, when the light-emitting diode is divided into chips, the light-emitting diode is manufactured in a state where a large number of light-emitting diodes are scattered from one wafer at a time, and the productivity of the process of manufacturing the next light-emitting diode lamp is inferior. There was a problem.
International Publication No. 05/029572 Pamphlet

  The present invention has been made in view of the above circumstances, and has excellent heat dissipation, and is manufactured not in a state where a large number of light emitting diodes are scattered at a time, but in a state where a large number of light emitting diodes are aligned. And it aims at providing the manufacturing method of the light emitting diode which can be easily chip-ized from there.

In order to achieve the above object, the present invention employs the following configuration. That is,
(1) A step of forming a compound semiconductor layer composed of an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer on a substrate and sequentially laminating a reflective p-type ohmic electrode and a seed layer on the compound semiconductor layer. And a step of forming a plating layer on the seed layer, affixing a temporary attachment substrate to the plating layer, removing the substrate from the n-type semiconductor layer, and extracting light from the n-type semiconductor layer Exposing the light-extracting surface, forming the n-type ohmic electrode on the light extraction surface, removing the temporary attachment substrate, irradiating the plating layer with laser light to form a re-fused portion, And a step of dividing the plated layer along the re-fused portion.
(2) In the step of sequentially laminating a reflective p-type ohmic electrode and a seed layer on the compound semiconductor layer, the compound semiconductor layer is provided with a separation groove to divide the compound semiconductor layer into a plurality of compounds, and each compound After forming the reflective p-type ohmic electrode on the semiconductor layer, a planarizing resist layer is formed in the separation groove, and the upper surface of the reflective p-type ohmic electrode and the upper surface of the resist layer are planarized. The resist layer is formed after the step of forming the seed layer on the planarized surface and removing the substrate from the n-type semiconductor layer to expose the light extraction surface of the n-type semiconductor layer. The method for producing a light-emitting diode according to (1), wherein the light-emitting diode is removed.
(3) The method for producing a light-emitting diode according to any one of (1) and (2), wherein the thickness of the plating layer is 40 to 80 μm.
(4) In the step of forming an n-type ohmic electrode on the n-type semiconductor layer, after the light extraction surface is dry-etched with an etching gas containing the same element as the dopant element in the n-type semiconductor layer The method for manufacturing a light-emitting diode according to any one of (1) to (3), wherein an n-type electrode is formed on the light extraction surface.
(5) The separation groove between the step of removing the substrate from the n-type semiconductor layer to expose the light extraction surface of the n-type semiconductor layer and the step of forming an n-type ohmic electrode on the light extraction surface. An insulating film for protecting a compound semiconductor layer is formed on the bottom and side surfaces of the light-emitting diode according to any one of (1) to (4).
(6) After forming an insulating film for protecting the compound semiconductor layer on the bottom and side surfaces of the separation groove, the light extraction surface is roughened before the step of forming an n-type ohmic electrode on the light extraction surface. The method for producing a light-emitting diode according to any one of (1) to (5), wherein:

  According to the above configuration, it has excellent heat dissipation and is manufactured not in a state where a large number of light emitting diodes are scattered at a time, but in a state in which a large number of light emitting diodes are aligned, and it can be easily chipped from there. The manufacturing method of the light emitting diode which can be performed can be provided.

Hereinafter, modes for carrying out the present invention will be described.
(Embodiment 1)
FIG. 1 is a schematic cross-sectional view showing an example of a light emitting diode according to an embodiment of the present invention. The light emitting diode shown in FIG. 1 shows an example of an upper and lower electrode structure.

As shown in FIG. 1, the light emitting diode 100 includes an n-type ohmic electrode 10, a compound semiconductor layer 20, a reflective p-type ohmic electrode 30, a seed layer 73, a plating layer 70, and an insulating film 35. .
A re-fused portion 59 is formed on the side surface of the plating layer 70.

The n-type ohmic electrode 10 becomes an anode of the compound semiconductor layer 20 by making ohmic contact with the n-type semiconductor layer 21 constituting the compound semiconductor layer 20. An n-type ohmic electrode 10 shown in FIG. 1 includes three layers including a Cr film 13 in contact with an n-type semiconductor layer 21, a Ti film 12 stacked on the Cr film 13, and an Au film 11 stacked on the Ti film 12. It is structured.
The n-type ohmic electrode 10 is not limited to this three-layer structure, and may be, for example, a four-layer structure in which a Ti film, an Al film, a Ti film, and an Au film are stacked.
As will be described later, the n-type ohmic electrode 10 is formed by sequentially laminating the Cr film 13, the Ti film 12, and the Au film 11 after dry etching the light extraction surface 20a. An ohmic contact is obtained with the n-type semiconductor layer 21.

  The compound semiconductor layer 20 is configured by stacking a p-type semiconductor layer 23, a light emitting layer 22, and an n-type semiconductor layer 21. The upper surface 20a of the compound semiconductor layer 20 is a light extraction surface 20a for extracting light from the light emitting layer 22 to the outside, and the n-type ohmic electrode 10 is formed on the light extraction surface 20a. Further, the light extraction surface 20a is roughened by means such as etching, so that the light extraction efficiency of the light emitting diode 100 is further enhanced.

Furthermore, an insulating film 35 made of an insulating material such as SiO ₂ is formed on the side surface 20b of the compound semiconductor layer 20 and the outer peripheral portion of the light extraction surface 20a. The insulating film 35 has a role of protecting the side surface of the compound semiconductor layer 20. The insulating film 35 extends to the side surface of the reflective p-type ohmic electrode 30 and the upper surface of the seed layer 73. By forming the insulating film 35, for example, even when a foreign matter adheres to the side surface of the compound semiconductor layer 20, a short circuit between the n-type semiconductor layer 21 and the p-type semiconductor layer 23 due to the foreign matter can be prevented.

  The reflective p-type ohmic electrode 30 is electrically connected to the plated layer 70 via the seed layer 73, and the plated layer 70 serves as an extraction electrode for the reflective p-type ohmic electrode 30. In addition, the reflective p-type ohmic electrode 30 and the plating layer 70 and the n-type ohmic electrode 10 have a relationship of being disposed on both sides in the thickness direction of the compound semiconductor layer 20. Thereby, the light emitting diode 100 which is embodiment of this invention is a light emitting diode of what is called an upper-lower electrode structure.

As shown in FIG. 1, a reflective p-type ohmic electrode 30 is disposed below the compound semiconductor layer 20. The reflective p-type ohmic electrode 30 serves as a positive electrode of the compound semiconductor layer 20 by making ohmic contact with the p-type semiconductor layer 23 constituting the compound semiconductor layer 20.
The reflective p-type ohmic electrode 30 includes an ohmic contact layer 31 in contact with the compound semiconductor layer 20, a reflective layer 32 in contact with the ohmic contact layer 31, and an interdiffusion prevention layer 33 in contact with the reflective layer 32. . By providing the reflective layer 32, the reflective p-type ohmic electrode 30 can reflect the light emitted from the light emitting layer 22 to the light extraction surface 20a side.
As will be described later, the reflective p-type ohmic electrode 30 is formed by laminating an ohmic contact layer 31 by an RF sputtering method, and the reflective layer 32 and the mutual diffusion prevention layer 33 are laminated by, for example, a DC sputtering method. . As a result, ohmic contact with the compound semiconductor layer 20 can be obtained without annealing.

  As the performance required for the ohmic contact layer 31, it is essential that the contact resistance with the p-type semiconductor layer 23 is small. The material of the ohmic contact layer 31 is preferably a platinum group such as Pt, Ru, Os, Rh, Ir, Pd, or Ag, and more preferably Pt, Ir, Rh, or Ru, from the viewpoint of contact resistance with the p-type semiconductor layer 23. , Pt is particularly preferred. Using Ag is preferable for obtaining good reflection, but the contact resistance is lower than Pt. Therefore, Ag can be used for applications that do not require much contact resistance. The thickness of the ohmic contact layer 31 is preferably 0.1 nm or more in order to stably obtain a low contact resistance. More preferably, it is 1 nm or more, and uniform contact resistance is obtained.

  On the ohmic contact layer 31, a reflective layer 32 such as an Ag alloy or an Al alloy is laminated. Pt, Ir, Rh, Ru, OS, Pd, and the like have a lower reflectance from visible light to ultraviolet region than Ag alloys. Therefore, it is difficult to obtain an element with high output because the light from the light emitting layer 22 is not sufficiently reflected. In this case, it is better to form the ohmic contact layer 31 thin enough to allow light to pass therethrough, and to form the reflection layer 32 such as an Ag alloy to obtain the reflected light, thereby obtaining good ohmic contact and higher output. An element can be created. In this case, the film thickness of the ohmic contact layer 31 is preferably 30 nm or less. More preferably, it is 10 nm or less. The thickness of the reflective layer 32 is preferably 0.1 nm or more in order to obtain a good reflectance. More preferably, it is 1 nm or more, and uniform adhesion is obtained. The Ag alloy is easy to cause migration, so the thinner one is preferable. Therefore, the film thickness is preferably 200 nm or less.

  The mutual diffusion preventing layer 33 is formed to prevent mutual diffusion between the constituent elements of the reflective layer 32 and constituent elements of the seed layer 73 described later. As the interdiffusion prevention layer 33, for example, Pt or the like is preferably used.

Next, as shown in FIG. 1, a seed layer 73 is disposed below the reflective p-type ohmic electrode 30. The seed layer 73 is a layer that becomes a base when the plating layer 70 is formed by a plating method, and is formed of a laminated film of a Ti film 74, a Ta film 75, and a Cu film 76. Here, the Ta film 75 functions as a barrier for Cu.
The thickness of the Ti film 74 is preferably about 100 to 300 nm, for example, the thickness of the Ta film 75 is preferably about 200 to 700 nm, and the thickness of the Cu film 76 is preferably about 100 to 500 nm, for example. The total thickness of the seed layer 73 is preferably about 400 to 1500 nm, for example.
The seed layer 73 may be formed as a single layer film made of Cu.

The plating layer 70 is a metal layer formed, for example, by electroplating using the seed layer 73 as a base. The material of the plating layer 70 is preferably a material corresponding to the material of the seed layer 73. When the seed layer 73 is a laminated film of the Ti film 74, the Ta film 75, and the Cu film 76, the seed layer 73 is formed. It is preferable to use Cu which is the same material as the Cu film 76 to be formed.
Cu is preferable as a material of the base of the light emitting diode 100 having the upper and lower electrode structures even in terms of high thermal conductivity. By providing the plated layer 70 made of Cu having high thermal conductivity, the heat generated in the light emitting layer 22 can be easily released to the outside, and the heat dissipation efficiency of the light emitting diode 100 can be improved.
Furthermore, Cu is preferable as a material of the base of the light emitting diode 100 having the upper and lower electrode structure in that the electric resistance is low. Since the plated portion 70 made of Cu is joined to the reflective p-type ohmic electrode 30 via the seed layer 73, it can be used as a conductive terminal, and it is not necessary to use a wire connected to the p-type terminal. Productivity as a light emitting diode lamp can be increased.

  The thickness of the plating layer 70 is preferably 40 to 80 μm, and more preferably about 60 μm. When the thickness of the plating layer 70 is less than 40 μm, the plating layer 70 is too thin, so that the durability as a light emitting diode is not only inferior, but the handling becomes difficult and the production efficiency is lowered. On the other hand, when it exceeds 80 μm, it becomes difficult to divide into light emitting diodes by laser scribing.

  In FIG. 1, re-fused portions 59 are formed on two side surfaces 70 b of the plated layer 70. As will be described later, the re-fused portion 59 is a part of the plating layer 70 that has been melted once by laser irradiation and then re-fused. This is a material region that has a fragile structure that can be easily broken down. By applying a slight mechanical stress to the re-fused portion 59, it can be easily divided into individual light emitting diodes.

As described above, the compound semiconductor layer 20 is roughly composed of the p-type semiconductor layer 23, the light emitting layer 22, and the n-type semiconductor layer 21.
As the compound semiconductor layer 20, a known semiconductor light emitting material such as a GaN-based single crystal, a GaP-based single crystal, a GaAs-based single crystal, or a ZnO-based single crystal can be used, and it is composed of a sapphire single crystal or a SiC single crystal described later. A GaN-based single crystal or a ZnO-based single crystal is more preferable, and a GaN-based single crystal is more preferable in that it can be epitaxially grown on the substrate.

As the semiconductor layer made of GaN based single crystal, and for example, the general formula _{Al X Ga Y In Z N 1} -A MA (0 ≦ X ≦ 1,0 ≦ Y ≦ 1,0 ≦ Z ≦ 1, X + Y + Z = 1. The symbol M represents a group V element different from nitrogen (N), and 0 ≦ A <1.) Many GaN-based semiconductors are known, and these well-known GaN-based semiconductors are also used in the present invention. including semiconductor and the general formula _{Al X Ga Y in Z N 1} -a M a (0 ≦ X ≦ 1,0 ≦ Y ≦ 1,0 ≦ Z ≦ 1, X + Y + Z = 1. symbol M nitrogen (N) Represents a different group V element, and 0 ≦ A <1). A GaN-based semiconductor represented by 0) can be used without any limitation.

  The n-type semiconductor layer 21 is configured by laminating a base layer, an n-contact layer, and an n-cladding layer in contact with the light emitting layer 22. The n contact layer can also serve as an underlayer and / or an n clad layer.

The underlayer is preferably composed of an Al _X Ga _1- XN layer (0 ≦ X ≦ 1, preferably 0 ≦ X ≦ 0.5, more preferably 0 ≦ X ≦ 0.1). The film thickness is 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more. An Al _X Ga _1-X N layer with good crystallinity is more easily obtained when the thickness is increased.
The underlayer may be doped with n-type impurities within the range of 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ , but undoped (<1 × 10 ¹⁷ / cm ³ ) is a better crystal. It is preferable in terms of maintaining the property. Although it does not specifically limit as an n-type impurity, For example, Si, Ge, Sn, etc. are mentioned, Preferably it is Si and Ge, More preferably, it is Si.

The n contact layer is composed of an Al _x Ga _1-x N layer (0 ≦ x ≦ 1, preferably 0 ≦ x ≦ 0.5, more preferably 0 ≦ x ≦ 0.1), as in the case of the underlayer. It is preferable.
The n contact layer is preferably doped with an n-type impurity, and the n-type impurity is preferably 1 × 10 ¹⁷ to 1 × 10 ¹⁹ / cm ³ , preferably 1 × 10 ¹⁸ to 1 × 10 ¹⁹ / cm ^3. Is preferable in terms of maintaining good ohmic contact with the n-type ohmic electrode 9, suppressing the occurrence of cracks, and maintaining good crystallinity. Although it does not specifically limit as an n-type impurity, For example, Si, Ge, Sn, etc. are mentioned, Preferably it is Si and Ge, More preferably, it is Si.
The GaN-based semiconductor constituting the n contact layer preferably has the same composition as that of the base layer, and the total film thickness of the n contact layer and the base layer is 1 to 20 μm, preferably 2 to 15 μm, more preferably 3 to 3. It is preferable to set in the range of 12 μm. When the total film thickness of the n-contact layer and the underlayer is in the above range, the crystallinity of the semiconductor is favorably maintained.

It is preferable to provide an n clad layer between the n contact layer and the light emitting layer 22. This is because the deterioration of the flatness generated on the surface of the n contact layer can be filled. The n-clad layer can be formed of AlGaN, GaN, GaInN, or the like. Alternatively, a heterojunction of these structures or a superlattice structure in which a plurality of layers are stacked may be used. Needless to say, when the n-cladding layer is formed of GaInN, it is preferably larger than the GaInN band gap of the light emitting layer 22. Moreover, it is preferable to comprise from a semiconductor material with a high refractive index.
The thickness of the n-clad layer is not particularly limited, but is preferably 0.005 to 0.5 μm, more preferably 0.005 to 0.1 μm. The n-type doping concentration of the n-clad layer is preferably 1 × 10 ¹⁷ to 1 × 10 ²⁰ / cm ³ , more preferably 1 × 10 ¹⁸ to 1 × 10 ¹⁹ / cm ³ . A doping concentration within this range is preferable in terms of maintaining good crystallinity and reducing the operating voltage of the device.

Next, as the light emitting layer 22 laminated on the lower side of the n-type semiconductor layer 21, a GaN-based semiconductor is preferable. For example, a Ga _{1 -S} In _S N (0 <S <0.4) GaN-based semiconductor is used. Can be mentioned.
The light emitting layer 22 may have any structure of double hetero (hereinafter referred to as DH), single quantum well (hereinafter referred to as SQW), or multiple quantum well (hereinafter referred to as MQW).
In the case of SQW, the film thickness of the light emitting layer 22 is not particularly limited, but is preferably a film thickness at which a quantum effect is obtained, that is, a critical film thickness, for example, 1 to 10 nm, more preferably 2 to 6 nm. The film thickness of the light emitting layer 22 is preferably in the above range in terms of light emission output.
In addition to the single quantum well (SQW) structure as described above, the light emitting layer 22 uses the Ga _{1 -S} In _S N as a well layer, and Al _c Ga _1-1 having a larger band gap energy than the well layer. _A multiple quantum well (MQW) structure including a _c N (0 ≦ c <0.3) barrier layer may be employed. The well layer and the barrier layer may be doped with impurities.

Next, the p-type semiconductor layer 23 is configured by laminating a p-cladding layer in contact with the light emitting layer 22 and a p-contact layer. However, the p contact layer may also serve as the p clad layer.
The p-cladding layer is not particularly limited as long as it has a composition larger than the band gap energy of the light-emitting layer 22 and can confine carriers in the light-emitting layer 22, but is preferably Al _d Ga _1-d N ( 0 <d ≦ 0.4, preferably 0.1 ≦ d ≦ 0.3). If the p-cladding layer is made of such AlGaN, it is preferable in terms of confinement of carriers in the light-emitting layer 7. The thickness of the p-clad layer is not particularly limited, but is preferably 1 to 400 nm, more preferably 5 to 100 nm. The p-type doping concentration of the p-clad layer is preferably 1 × 10 ¹⁸ to 1 × 10 ²¹ / cm ³ , more preferably 1 × 10 ¹⁹ to 1 × 10 ²⁰ / cm ³ . When the p-type dope concentration is in the above range, a good p-type crystal can be obtained without reducing the crystallinity.

The p-contact layer comprises at least Al _e Ga _1-e N (0 ≦ e <0.5, preferably 0 ≦ e ≦ 0.2, more preferably 0 ≦ e ≦ 0.1). Is a layer. When the Al composition is in the above range, it is preferable in terms of maintaining good crystallinity and good ohmic contact with the reflective p-type ohmic electrode 30. When a p-type impurity (dopant) is contained at a concentration of 1 × 10 ¹⁸ to 1 × 10 ²¹ / cm ³ , preferably at a concentration of 5 × 10 ^{19 to} 5 × 10 ²⁰ / cm ³ , good ohmic contact It is preferable from the standpoints of maintaining the thickness, preventing the occurrence of cracks, and maintaining good crystallinity. Although it does not specifically limit as a p-type impurity, For example, Preferably Mg is mentioned. Although a film thickness is not specifically limited, 0.01-0.5 micrometer is preferable, More preferably, it is 0.05-0.2 micrometer. When the film thickness is within this range, it is preferable in terms of light emission output.
Next, the manufacturing method of the light emitting diode which is embodiment of this invention is demonstrated.

2-9 is schematic sectional drawing which shows the manufacturing method of the light emitting diode 100 which is embodiment of this invention.
The method of manufacturing the light emitting diode 100 according to the embodiment of the present invention includes a step of forming the compound semiconductor layer 20, a step of forming the separation groove 25, a stacking step of forming the reflective p-type ohmic electrode 30, and a resist layer. 81 (planarization resist layer) forming step, seed layer 73 forming step, plating layer 70 forming step, temporary attaching substrate 86 attaching step, and light extraction surface 20a are exposed. A step of removing the resist layer 81, a step of forming the insulating film 35, a step of roughening the light extraction surface 20a, a step of forming the n-type ohmic electrode 10, and a temporary attachment substrate 86. , A step of forming the re-fused portion 59, and a dividing step.
Hereinafter, each step will be described.

“Process of forming compound semiconductor layer 20”
As shown in FIG. 2, a compound semiconductor layer 20 is formed by sequentially stacking an n-type semiconductor layer 21, a light emitting layer 22, and a p-type semiconductor layer 23 on a substrate 1.

As the substrate 1, it is preferable to use a substrate suitable for epitaxial growth of a compound semiconductor layer such as a sapphire substrate. Other examples include III-V group compound semiconductor single crystal substrates such as GaAs, indium phosphide (hereinafter referred to as InP), gallium phosphide (hereinafter referred to as GaP), and silicon (hereinafter referred to as Si) substrates.
In addition, when the compound semiconductor layer 20 is formed on the substrate 1, it is desirable to form a buffer layer on the substrate 1 in advance. That is, when a sapphire substrate is used as the substrate 1 and GaN is formed as the n-type semiconductor layer 21, the lattice constants of the substrate 1 and the n-type semiconductor layer 21 are different by 10% or more. In this case, the crystallinity of GaN constituting the n-type semiconductor layer 21 can be improved by using AlN, AlGaN, or the like having an intermediate lattice constant between the substrate 1 and the n-type semiconductor layer 21 as the buffer layer. it can.

On the buffer layer, an n-type semiconductor layer 21, a light emitting layer 22, and a p-type semiconductor layer 23 are sequentially stacked to form the compound semiconductor layer 20.
The growth method of the compound semiconductor layer 20 is not particularly limited, and a GaN-based semiconductor such as sputtering, MOCVD (metal organic chemical vapor deposition), HVPE (hydride vapor deposition), MBE (molecular beam epitaxy) is grown. All known methods can be applied. A preferable growth method is a sputtering method or an MOCVD method from the viewpoint of film thickness controllability and mass productivity.

In the sputtering method, a GaN-based semiconductor is preferably formed by a so-called reactive sputtering method using a target containing Ga and a mixed gas of argon and nitrogen as a plasma gas.
In the MOCVD method, hydrogen (H ₂ ) or nitrogen (N ₂ ) as a carrier gas, trimethyl gallium (TMG) or triethyl gallium (TEG) as a Ga source which is a group III source, trimethyl aluminum (TMA) or Al as a source Triethylaluminum (TEA), trimethylindium (TMI) or triethylindium (TEI) as the In source, ammonia (NH ₃ ), hydrazine (N ₂ H ₄ ), or the like as the N source that is a group V raw material are used. In addition, as a dopant, for n-type, monosilane (SiH ₄ ) or disilane (Si ₂ H ₆ ) is used as a Si raw material, germanium gas (GeH ₄ ) or tetramethyl germanium ((CH ₃ ) ₄ Ge) is used as a Ge raw material. Or an organic germanium compound such as tetraethylgermanium ((C ₂ H ₅ ) ₄ Ge) can be used.
In the MBE method, elemental germanium can also be used as a doping source. For the p-type, for example, biscyclopentadienyl magnesium (Cp ₂ Mg) or bisethylcyclopentadienyl magnesium (EtCp ₂ Mg) may be used as the Mg raw material.

  The n-type semiconductor layer 21 is preferably doped with Si or the like as an n-type dopant, and the p-type semiconductor layer 23 is preferably doped with Mg or the like as a p-type dopant.

“Process of forming the separation groove 25”
As shown in FIG. 3A, the separation groove 25 is formed in the compound semiconductor layer 20 by patterning using a normal photolithography technique. The separation groove 25 is a region that determines the outer shape of the light emitting diode 100, and the light emitting diode 100 is partitioned and formed in a substantially lattice shape in plan view. In this way, the compound semiconductor layer 20 is divided into a plurality.

“Lamination process for forming reflective p-type ohmic electrode 30”
As shown in FIG. 3B, an ohmic contact layer 31, a reflective layer 32, and an interdiffusion prevention layer 33 are sequentially stacked on the p-type semiconductor layer 23 of the divided compound semiconductor layer 20 to reflect p-type. The ohmic electrode 30 is formed.

  In forming the ohmic contact layer 31 on the p-type semiconductor layer 23, it is preferable to form the ohmic contact layer 31 by a sputtering film forming method using RF discharge. By using a sputtering film formation method by RF discharge, an electrode having a lower contact resistance can be formed than by using a vapor deposition method or a DC discharge sputtering film formation method. That is, by forming the ohmic contact layer 31 by the sputtering film forming method using RF discharge, the constituent elements of the p-type semiconductor layer 23 are mixed in the ohmic contact layer 31, and the configuration of the ohmic contact layer 31 is included in the p-type semiconductor layer 23. As a result, the ohmic contact layer 31 and the p-type semiconductor layer 23 are in ohmic contact.

  In sputtering deposition by RF discharge, energy is given to sputtered atoms attached to the p-type semiconductor layer 23 by the ion assist effect, and surface diffusion is promoted between the p-type semiconductor, for example, Mg-doped p-GaN. it is conceivable that. Furthermore, it is considered that the film formation also has an effect of imparting energy to the outermost surface atoms of the p-type semiconductor layer 23 to promote the diffusion of a semiconductor material such as Ga into the ohmic contact layer 31.

  The film formation by RF discharge has an effect of lowering the contact resistance in the initial stage. However, when the film thickness is increased, the film is sparse, so that the reflectivity is inferior to the film formation by DC discharge. Therefore, it is possible to form the ohmic contact layer 31 whose thickness is reduced in the range where the contact resistance is kept low to increase the light transmittance by RF discharge, and the reflective layer 32 and the mutual diffusion prevention layer 33 are formed thereon by DC discharge. preferable.

  Thus, the ohmic contact layer 31 and the p-type semiconductor layer 23 can be brought into ohmic contact by forming the ohmic contact layer 31 by the RF sputtering method. In this case, annealing after forming the ohmic contact layer 31 is not required. Rather, annealing promotes the diffusion of each of Pt and Ga and lowers the crystallinity of the semiconductor, which may deteriorate the electrical characteristics, and the Ag alloy that is the reflective film migrates due to the annealing. Annealing is not preferable because the reflectance is lowered. Therefore, after the ohmic contact layer 31 is formed, it is preferable that the heat treatment is not performed at a temperature higher than 350 ° C.

Sputtering can be carried out by appropriately selecting conventionally known conditions using a conventionally known sputtering apparatus. First, the substrate 1 on which the compound semiconductor layer 20 is stacked is housed in a chamber, and the substrate temperature is set in the range of room temperature to 500 ° C. Substrate heating is not particularly required, but may be appropriately heated to promote diffusion of the constituent elements of the ohmic contact layer 31 and the constituent elements of the p-type semiconductor layer 23. The chamber is evacuated until the degree of vacuum becomes 10 ⁻⁴ to 10 ⁻⁷ Pa.
As the sputtering gas, He, Ne, Ar, Kr, Xe or the like can be used. Ar is desirable because of availability. One of these gases is introduced into the chamber and the discharge is performed after the pressure is set to 0.1 to 10 Pa. Preferably it sets to the range of 0.2-5Pa. The supplied power is preferably in the range of 0.2 to 2.0 kW. At this time, the thickness of the layer to be formed can be adjusted by adjusting the discharge time and supply power.

“Process of filling resist layer 81”
As shown in FIG. 4A, a resist layer 81 is formed in the separation groove 25. After the resist material is filled in the separation groove 25, it is solidified by exposure and development. As a result, the resist layer 81 is formed in a substantially lattice shape in plan view corresponding to the separation groove 25. The resist layer 81 functions as a protective layer for preventing the seed layer 73 formed in the next step from being formed in the separation groove 25. In addition, a well-known thing can be used as a resist material. The height of the resist layer 81 is formed to be equal to the depth of the separation groove 25.

“Step of forming seed layer 73”
Further, as shown in FIG. 4B, a Ti film 74, a Ta film 75, and a Cu film 76 are sequentially laminated on the surface 81a of the resist layer 81 and the surface 30a of the reflective p-type ohmic electrode 30. A seed layer 73 is formed.
The thickness of the Ti film 74 is preferably about 100 to 300 nm, for example, the thickness of the Ta film 75 is preferably about 200 to 700 nm, and the thickness of the Cu film 76 is preferably about 100 to 500 nm, for example. The total thickness of the seed layer 73 is preferably about 400 to 1500 nm, for example.
Examples of the method for forming the seed layer 73 include a vapor deposition method and a sputtering method.

"Plating process for forming the plating layer 70"
Next, as shown in FIG. 5A, a plating layer 70 is formed on the entire surface of the seed layer 73. The plating layer 70 may be formed by electroplating while supplying current to the seed layer 73. The thickness of the plating layer 70 at this time is preferably 40 to 80 μm, and more preferably 60 μm.
The electroplating process is a series of processes including degreasing, acid treatment, neutralization, water washing, electroplating, and water washing. Degreasing, acid treatment, neutralization, and water washing treatment are performed by appropriately selecting conditions according to need.
Cu or the like can be used as the material of the plating layer.

"Process of pasting temporary pasting substrate 86"
First, the thermal foam tape 85 is attached to the temporary attachment substrate 86. Next, as shown in FIG. 5B, the other surface side of the thermal foam tape 85 is bonded to the plating layer 70.
As the heat-foaming tape 85, a commonly used tape can be used, and examples thereof include Riva Alpha (manufactured by Nitto Denko Corporation).
By attaching the temporary attachment substrate 86, the light-emitting diode substrate can be easily handled, and the subsequent manufacturing process can be easily performed. When the temporary attachment substrate 86 is not attached, the plating layer 70 is thin, lacks in strength, and easily deforms, so that handling becomes difficult.

“Process for exposing light extraction surface 20a”
Further, as shown in FIG. 5B, the laser 90 is irradiated from the substrate 1 side to the vicinity of the interface between the substrate 1 and the compound semiconductor layer 20. As a result, the buffer layer at the interface portion can be pyrolyzed, and the substrate 1 is laminated with the compound semiconductor layer 20, the reflective p-type ohmic electrode, the seed layer 73, and the plating layer 70 as shown in FIG. It can be peeled off from the temporary attachment substrate 86.
As the laser 90, a commonly used one can be used.

  As a method for removing the buffer layer and the substrate 1, it is preferable to use the laser lift-off method described above. This is because the laser lift-off method has the highest productivity. However, other known techniques such as a polishing method and an etching method can also be used.

“Step of removing resist layer 81”
Next, as shown in FIG. 6B, the resist layer 81 formed in the separation groove 25 is removed. It can be removed with a normal resist removal solvent such as NMP.

“Process for forming insulating film 35”
Next, as shown in FIG. 7A, a protective insulating film 35 is formed on each side surface (divided surface) 20 b of the compound semiconductor layer 20 divided into element shapes by the separation grooves 25.
Specifically, as shown in FIG. 7A, the insulating film 35 is formed so as to cover the bottom surface 25 a and the side surface 25 b of the separation groove 25 and the outer peripheral portion of the light extraction surface 20 a of each compound semiconductor layer 20. .
Examples of the material of the insulating film 35 include SiO _2, and examples of the film forming method include means such as a CVD method and a sputtering method.
After the insulating film 35 is formed on the entire compound semiconductor layer 20, the above-described insulating film 35 can be formed by forming a resist layer on the outer peripheral portion of the light extraction surface 20a and performing dry etching. Alternatively, after the resist layer is formed in the central portion of the light extraction surface 20a, the insulating film 35 is formed on the entire compound semiconductor layer 20, and the resist layer is removed to form the insulating film 35. good.

“Roughening of the light extraction surface 20a”
Next, as shown in FIG. 7B, the light extraction surface 20a of the compound semiconductor layer 20 is roughened.
Roughening means that minute irregularities are formed on the surface and can be formed chemically or mechanically.
Specifically, the light extraction surface 20a of the compound semiconductor layer 20 is immersed in a heated KOH solution. As a result, it is possible to remove the underlying layer present on the surface of the exposed portion of the light extraction surface 20a and to roughen the light extraction surface 20a of the compound semiconductor layer 20.
PEC (photoelectrochemical etch) can also be used for the removal of the underlayer and the surface roughening. The removal of the underlayer and the roughening of the light extraction surface 20a can also be performed by dry etching.
Moreover, the above-described operation for removing the underlayer is an operation necessary when the underlayer is an undoped layer, and when the underlayer is doped with Si or the like, the operation for removing the underlayer is not necessary.

“Process of forming n-type ohmic electrode 10”
After dry etching the light extraction surface 20a of the compound semiconductor layer 20 with an etching gas containing the same element as the dopant element in the n-type semiconductor layer 21, as shown in FIG. 8A, the light extraction surface 20a is formed on the light extraction surface 20a. An n-type ohmic electrode 10 is formed.
For example, a temporary attachment substrate 86 in which a plating layer 70, a seed layer 73, a reflective p-type ohmic electrode 30 and a compound semiconductor layer 20 are fixed with a thermal foam tape 85 is housed in a chamber of a plasma dry etching apparatus, and is n-type. A reaction gas composed of an etching gas containing the same element as the dopant element in the semiconductor layer 21 is supplied into the chamber, plasma is generated above the compound semiconductor layer 20, and the light extraction surface 20a is formed by the plasma containing the etching gas. Perform dry etching.

As the etching gas, when the dopant element in the n-type semiconductor layer 21 is silicon (Si), it is preferable to use silicon halide as the etching gas, and specifically, SiCl ₄ or SiF ₄ is preferable.
The pressure in the chamber when the reaction gas is introduced is preferably in the range of 0.2 to 2 Pa, for example, the flow rate of the etching gas is preferably in the range of 15 sccm to 50 sccm, and the plasma power is preferably about 120 W. The bias is preferably about 50 W, and the processing time is preferably about 150 seconds.
By performing such an etching process, Si contained in the etching gas is implanted in the vicinity of the surface of the n-type semiconductor layer 21, and the Si concentration in the vicinity of the surface is increased.

Next, the n-type ohmic electrode 10 is formed by sequentially laminating the Cr film 13, the Ti film 12, and the Au film 11 on the n-type semiconductor layer 21 that has been subjected to the plasma treatment.
The n-type ohmic electrode 10 is not limited to this three-layer structure, and a four-layer structure in which a Ti film, an Al film, a Ti film, and an Au film are stacked may be used.
Examples of a method for forming the n-type ohmic electrode 10 include a sputtering method and a vapor deposition method.
In this way, after the surface of the n-type semiconductor layer 21 is treated with plasma, a Cr film or a Ti film or the like is stacked, so that the Cr film or the Ti film and the n-type semiconductor layer constituting the n-type ohmic electrode 10 are stacked. 21 can be brought into ohmic contact. In this case, annealing after the formation of the n-type ohmic electrode 10 is not required. Rather, the electrical characteristics may be deteriorated by annealing, and the Ag alloy of the reflective film causes migration due to annealing, which is not preferable.

“Process to remove temporary sticking substrate 86”
As shown in FIG. 8B, heat is applied to the thermal foam tape 85, and the temporary attachment substrate 86 is removed.
For example, by heating to a predetermined temperature with an oven or a hot plate, the thermal foam tape 85 starts to foam, and the temporary attachment substrate 86 can be easily removed.

“Process for forming the re-fused portion 59”
Next, as shown in FIG. 9A, a re-fused portion 59 is formed in the plated layer 70 by irradiating a laser 92 using a laser scribing method.
First, for example, the light extraction surface 20a side is fixed to the heat-resistant substrate with an adhesive tape or the like. The heat-resistant substrate is disposed in order to prevent the laser 92 penetrating the plating layer 70 from burning the lower stage.

Next, laser scribing is performed by scanning the vertical line m while irradiating the laser 92 from the plated layer 70 side at a position substantially at the center of the separation groove 25, thereby forming the re-fused portion 59. The re-fused portion 59 is a fragile material region. The re-fused portion 59 of the plating layer once irradiated and heated by the laser 92 is re-fused as the temperature decreases as the laser 92 is scanned. However, since the temperature is rapidly decreased after the temperature is rapidly increased, the material characteristics of the plating layer 70 change and the structure easily collapses.
The re-fused portion 59 is formed in a substantially lattice shape in plan view so as to separate the light emitting diodes.
Further, as the laser 92, a commercially available laser having a wavelength range of 266 to 1064 nm is used, and its output is increased.

"Division process"
By attaching an adhesive tape to the plated layer 70 side and applying mechanical stress to the re-fused portion 59, as shown in FIG. It can be easily divided into 100. Moreover, since the adhesive tape is affixed to the entire surface, it is not scattered and can be handled in a state where the light emitting diodes are aligned one by one, and the manufacture of the light emitting diode lamp can be facilitated.
Hereinafter, effects of the embodiment of the present invention will be described.

  In the method of manufacturing the light emitting diode 100 according to the embodiment of the present invention, the compound semiconductor layer 20 including the n-type semiconductor layer 21, the light emitting layer 22, and the p-type semiconductor layer 23 is formed on the substrate 1. A step of sequentially laminating a reflective p-type ohmic electrode 30 and a seed layer 73 thereon, a step of forming a plating layer 70 on the seed layer 73, and a step of attaching a temporary attachment substrate 86 to the plating layer 70; a step of removing the substrate 1 from the n-type semiconductor layer 21 to expose the light extraction surface 20a of the n-type semiconductor layer 21, a step of forming the n-type ohmic electrode 10 on the light extraction surface 20a, and a temporary attachment substrate 86. And a step of dividing the plating layer 70 along the re-fusion portion 59 after forming the re-fusion portion 59 by irradiating the plating layer 70 with laser light. Therefore, a plurality of light emitting diodes 100 can be formed on the plated layer 70 in an aligned state, but a re-fused portion 59 is formed on the plated layer 70 between the light emitting diodes 100. Therefore, the plating layer 70 can be divided at the re-fused portion 59. Thereby, the light emitting diode 100 can be easily divided together with the plating layer 70. Thus, since the conventional laser scribing method can be applied when dividing the light emitting diode 100 having the plated layer 70, the light emitting diodes 100 can be emitted without scattering the light emitting diodes 100 when the light emitting diodes 100 are divided. The manufacturing efficiency of the diode lamp can be improved.

  In the method of manufacturing the light emitting diode 100 according to the embodiment of the present invention, the compound semiconductor layer 20 is provided with the separation groove 25 to divide the compound semiconductor layer 20 into a plurality of parts, and then the insulating film 35 is provided on the side surface 25b of the separation groove 25. Is generated when the laser 92 is directly irradiated and divided into the light emitting diodes 100, and the compound semiconductor layer 20 is attached to the side surface 25b of the compound semiconductor layer 20 due to the influence of dust or the like that causes leakage. The device characteristics of the light emitting diode 100 can be protected.

  The manufacturing method of the light emitting diode 100 according to the embodiment of the present invention is such that the plating layer 70 has a thin film thickness of 40 to 80 μm. Therefore, the light emitting diode 100 is easily formed after the re-fused portion 59 is formed by a laser scribe method. Can be divided into

  Since the method for manufacturing the light emitting diode 100 according to the embodiment of the present invention uses a laser scribing method in the step of forming the refused portion 59 in the plated layer 70, the refused for easily partitioning the light emitting diode 100. A portion 59 can be formed.

  A light emitting diode 100 according to an embodiment of the present invention includes a compound semiconductor layer 20 including a reflective p-type ohmic electrode 30, a p-type semiconductor layer 23, a light-emitting layer 22, and an n-type semiconductor layer 21 on a plating layer 70, and n Since the configuration includes at least the type ohmic electrode 10, the heat from the light emitting layer 22 can be easily released to the outside through the plating layer 70.

  Moreover, since the manufacturing method of the light emitting diode 100 which is embodiment of this invention comprises the process of forming the plating layer 70 in the seed layer 73, the reflective p-type ohmic electrode 30 and the plating layer 70 are comprised. Since it is a structure which can ensure electroconductivity, a light emitting diode lamp can be easily manufactured using the plating layer 70 as a p-type terminal, and the manufacturing efficiency and manufacturing cost can be improved.

  Moreover, since the manufacturing method of the light emitting diode 100 which is embodiment of this invention comprises the process of forming the plating layer 70 in the seed layer 73, the plating layer 70 is firmly joined through the seed layer 73. The light emitting diode 100 having excellent mechanical strength can be manufactured.

  In addition, the method for manufacturing the light emitting diode 100 according to the embodiment of the present invention includes a step of dividing the light emitting diode 100 by dividing the light emitting diode 100 by a re-fused portion 59 formed in a substantially lattice shape in plan view and formed in a fragile structure. Since the configuration is provided, it can be easily divided into chips.

Furthermore, since the light emitting diode 100 according to the embodiment of the present invention has a structure in which the structure of the re-fused portion 59 has a fragile region, it is easily divided by the re-fused portion 59 when dividing into chips. Can do.
Hereinafter, the present invention will be specifically described based on examples. However, the present invention is not limited only to these examples.

A light emitting diode as shown in FIG. 1 was prepared by the following steps.
“Process of forming compound semiconductor layer”
A buffer layer made of AlN having a thickness of 40 nm is formed on a substrate made of sapphire, an undoped GaN underlayer having a thickness of 2 μm, a Si-doped n-type GaN contact layer having a thickness of 2 μm, and a thickness of 20 nm are formed on the buffer layer. An n-type In _0.1 Ga _0.9 N cladding layer (n-type semiconductor layer), a Si-doped GaN barrier layer having a thickness of 15 nm, and an In _0.2 Ga _0.8 N well layer having a thickness of 2 nm are stacked five times. Finally, a light emitting layer having a multi-well structure provided with a barrier layer, a Mg-doped p-type Al _0.1 Ga _0.9 N cladding layer having a thickness of 10 nm, and a Mg-doped p-type Al _0.02 Ga _{0. A 98} N contact layer (p-type semiconductor layer) was sequentially laminated to obtain a compound semiconductor layer.

"Process for forming the separation groove"
By performing patterning using a normal photolithography technique, separation grooves having a substantially lattice shape in plan view were formed. After the photolithography process using the resist AZ4330, a separation groove forming process is performed by dry etching using a mixed gas of BCl ₃ —Cl ₂ .
"Lamination process to form reflective p-type ohmic electrodes"
An ohmic contact layer made of Pt having a thickness of 2 nm, a reflective layer made of an Ag alloy having a thickness of 100 nm, and an interdiffusion prevention layer made of Pt having a thickness of 50 nm are sequentially laminated on the p-type semiconductor layer, and then photolithography technology A reflective p-type ohmic electrode was formed by patterning with the above method. In forming the ohmic contact layer on the p-type semiconductor layer, the ohmic contact layer was formed by a sputtering film forming method using RF discharge. The reflection layer and the mutual diffusion prevention layer were formed by DC sputtering.

"Process to form resist layer"
A resist (trade name: AZ5200NJ) was filled in the separation groove, and then exposed and developed to form a resist layer.

“Process of forming seed layer”
A 200 nm thick Ti film, a 400 nm thick Ta film, and a 300 nm thick Cu film are sequentially deposited by sputtering on the entire exposed surface of the resist layer and the entire bottom surface of the diffusion preventing layer made of a Pt film. A layer was formed.

“Process of forming plating layer”
A plating layer was formed to a thickness of about 60 μm so as to cover the seed layer by electroplating while passing an electric current through the seed layer. The electroplating conditions were 2.5 A / dm ² × 1.83 hr.

"Process of pasting a temporary pasting substrate"
First, after sticking one surface side of a heat foaming tape to a temporary attachment board | substrate, the other surface side of this heat foaming tape is bonded together to a plating layer.
As the thermal foam tape, Riva Alpha (manufactured by Nitto Denko Corporation) was used.

“Process to expose the light extraction surface”
The two bonded substrates were placed in a laser irradiation apparatus, and the buffer layer and the sapphire substrate were removed from the n-type semiconductor layer by a laser lift-off method.
Specifically, focusing was performed near the junction between the compound semiconductor layer and the sapphire substrate, laser irradiation was performed, and the entire surface of the substrate was scanned. As a result, the sapphire substrate could be easily removed. An ArF (193 nm) excimer laser was used.

"Process to remove resist"
The resist layer formed in the separation groove was removed. A normal resist removing method such as NMP was used.

"Process for forming insulating film"
After carrying the substrate into the chamber and reducing the pressure, an insulating film made of SiO ₂ having a thickness of 460 nm was formed on each side surface of the compound semiconductor layer divided into a plurality by the separation grooves by a CVD method.
"Roughening the light extraction surface"
The substrate was removed from the chamber, and the light extraction surface of the n-type semiconductor layer was immersed in a heated KOH solution to roughen the light extraction surface.

“Process of forming n-type ohmic electrode”
Dry etching with SiCl ₄ was performed on the light extraction surface of the n-type semiconductor layer. Specifically, a plating substrate including a compound semiconductor layer is accommodated in a chamber of a plasma dry etching apparatus, SiCl ₄ gas is supplied as a reaction gas into the chamber, plasma is generated above the compound semiconductor layer, and a light extraction surface is obtained. Was etched.
The pressure in the chamber when the reaction gas is introduced is set to 0.5 Pa, the flow rate of the etching gas is set to 30 sccm, the plasma power is set to 120 W, the bias is set to 50 W, and the processing time is 150 seconds. Set to.
Furthermore, an n-type ohmic electrode was formed by sequentially depositing a Cr film with a thickness of 40 nm, a Ti film with a thickness of 100 nm, and an Au film with a thickness of 1000 nm on the n-type semiconductor layer after the dry etching process. .

"Process to remove temporary attachment substrate"
The substrate was carried into an oven and heated at 150 ° C. for 1 minute. The heat-foaming tape was foamed, and it was easy to remove the temporary attachment substrate.

"Process for forming re-bonded part"
Using a laser scribing method, a lattice-shaped re-fused portion was formed on the insulating film by scanning the center line of the separation groove by irradiating a laser from the plated layer side. The laser irradiation intensity was adjusted, and the depth of the re-fused portion formed by the laser was set to penetrate the plating layer.

"Division process"
By sticking an adhesive tape on the plated layer side and applying mechanical stress to the re-fused portion, the light-emitting diode could be easily divided into the re-fused portion. In addition, since the adhesive tape is affixed to the entire surface, it is not scattered and can be handled in a state where the light emitting diodes are aligned one by one, and the light emitting diode lamp can be easily manufactured.

  The present invention is excellent in heat radiation, and it is possible to manufacture a large number of light emitting diodes in a collective state, and easily form a chip from them, instead of disassembling many light emitting diodes at once. The present invention relates to a light emitting diode that can be produced. Therefore, it may be used in the optical industry where light emitting diodes are used for various display lamps.

It is a cross-sectional schematic diagram which shows an example of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention. It is a schematic sectional drawing explaining an example of the manufacturing method of the light emitting diode which is embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate, 10 ... n-type ohmic electrode, 11 ... Au film, 12 ... Ti film, 13 ... Cr film, 20 ... Compound semiconductor layer, 20a ... Light extraction surface, 20b ... Side surface, 21 ... N-type semiconductor layer, 22 DESCRIPTION OF SYMBOLS ... Light emitting layer, 23 ... p-type semiconductor layer, 25 ... Separation groove, 25a ... Bottom surface, 25b ... Side surface, 30 ... Reflective p-type ohmic electrode, 31 ... Ohmic contact layer, 32 ... Reflective layer, 33 ... Interdiffusion prevention layer 35 ... Insulating film, 70 ... Plating layer, 70a ... Bottom, 70b ... Side, 59 ... Re-fusion part, 73 ... Seed layer, 74 ... Ti film, 75 ... Ta film, 76 ... Cu film, 81 ... Resist layer (Resist layer for flattening), 85 ... thermal foam tape, 86 ... temporarily attached substrate, 90, 92 ... laser, 100 ... light emitting diode, m ... perpendicular

Claims (6)

Forming a compound semiconductor layer comprising an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer on a substrate, and sequentially laminating a reflective p-type ohmic electrode and a seed layer on the compound semiconductor layer;
Forming a plating layer on the seed layer and attaching a temporary attachment substrate to the plating layer;
Removing the substrate from the n-type semiconductor layer to expose a light extraction surface of the n-type semiconductor layer;
Forming an n-type ohmic electrode on the light extraction surface;
Removing the temporary attachment substrate;
Irradiating the plated layer with laser light to form a re-fused portion, and then dividing the plated layer along the re-fused portion;
A method for manufacturing a light emitting diode, comprising: In the step of sequentially laminating a reflective p-type ohmic electrode and a seed layer on the compound semiconductor layer,
After providing a separation groove in the compound semiconductor layer to divide the compound semiconductor layer into a plurality, and forming a reflective p-type ohmic electrode on each compound semiconductor layer,
A flattening resist layer is formed in the separation groove to flatten the upper surface of the reflective p-type ohmic electrode and the upper surface of the resist layer, and the seed layer is formed on the flattened surface. With
2. The light-emitting diode according to claim 1, wherein the resist layer is removed after the step of removing the substrate from the n-type semiconductor layer to expose a light extraction surface of the n-type semiconductor layer. Method.   The method for manufacturing a light-emitting diode according to claim 1, wherein the plating layer has a thickness of 40 to 80 μm.   In the step of forming an n-type ohmic electrode on the n-type semiconductor layer, the light extraction surface is subjected to dry etching with an etching gas containing the same element as the dopant element in the n-type semiconductor layer, and then the light The method for manufacturing a light-emitting diode according to claim 1, wherein an n-type electrode is formed on the extraction surface. Between the step of removing the substrate from the n-type semiconductor layer to expose the light extraction surface of the n-type semiconductor layer and the step of forming an n-type ohmic electrode on the light extraction surface,
The method for manufacturing a light-emitting diode according to claim 1, wherein an insulating film for protecting the compound semiconductor layer is formed on a bottom surface and a side surface of the separation groove. After forming an insulating film for protecting the compound semiconductor layer on the bottom and side surfaces of the spacing groove, before the step of forming an n-type ohmic electrode on the light extraction surface,
The method for manufacturing a light-emitting diode according to claim 1, wherein the light extraction surface is roughened.

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