JP2010027643A - Nitride semiconductor light emitting element and fabrication process therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable nitride semiconductor light emitting element which exhibits high light extraction efficiency and high fabrication yield which reduce short circuit or current leak at a PN junction, and to provide a fabrication process therefor. <P>SOLUTION: A nitride semiconductor light emitting element including a conductive substrate, a bonding layer and a nitride semiconductor layer, in this order, is further provided with an insulating layer between the bonding layer and the nitride semiconductor layer, and the outer circumferential portion of the nitride semiconductor layer on the side of the bonding layer touches the surface of the insulating layer. The nitride semiconductor layer includes, at least, a second n-type nitride semiconductor layer, a p-type nitride semiconductor layer, a light emitting layer, and a first n-type nitride semiconductor layer, in this order, from side of the conductive substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nitride semiconductor light emitting device and a method for manufacturing a nitride semiconductor light emitting device.

  Conventional nitride semiconductor light emitting devices have been manufactured by laminating and growing a nitride semiconductor on an insulating substrate such as sapphire, spinel, lithium niobate, neodymium gallate and the like. However, when sapphire is used for an insulating substrate, for example, two electrodes must be taken out from the same surface side of the insulating substrate, so that the chip size becomes large and a large number of chips cannot be obtained from the wafer. There was a problem, and sapphire is very hard and has no cleaving ability, so that advanced technology is required to make a chip.

  Due to the above problems, it is difficult to reduce the size of a chip in a nitride semiconductor light emitting device using an insulating substrate. Therefore, another attempt has been made to grow a nitride semiconductor on a conductive substrate such as silicon carbide, silicon, zinc oxide, gallium arsenide, gallium phosphide, etc., but the above problem can still be solved completely. The current situation is not.

  In order to solve such a problem, Patent Document 1 discloses that a nitride semiconductor layer is laminated and grown on an insulating substrate such as sapphire, but finally has a conductive substrate, and the conductive substrate A method of manufacturing a nitride semiconductor light emitting device in which electrodes are taken out from above and below is disclosed. Hereinafter, an example of a method for manufacturing the nitride semiconductor light emitting device described in Patent Document 1 will be schematically described with reference to FIG.

First, on a sapphire substrate (not shown), a first n-type nitride semiconductor layer 941 made of Al _X Ga _1-X N (0 ≦ X ≦ 1) doped with donor impurities, and In _Y Ga _{1− The} light-emitting layer 942 made of YN (0 <Y <1) and the p-type nitride semiconductor layer 943 made of Al _x Ga _1-x N (0 ≦ X ≦ 1) doped with acceptor impurities. A first pasted metal layer 931 made of a silver paste is formed on the surface of the nitride semiconductor layer 94 to improve adhesion.

  Separately from the nitride semiconductor layer 94 formed above, a second adhesive metal layer 932 is formed on the surface of the p-type GaAs substrate 911 which is a conductive substrate, and the first adhesive metal layer 931 and the second adhesive metal layer are formed. After the layer 932 is bonded and bonded by heating, the sapphire substrate (not shown) is removed by polishing to expose the first n-type nitride semiconductor layer 941 of the nitride semiconductor layer 94. Thereafter, the first electrode 98 is formed on the first n-type nitride semiconductor layer 941, the second electrode 99 is formed on the surface of the p-type GaAs substrate 911, and the wafer of the nitride semiconductor light emitting device is formed. In addition, the wafer on which the second electrode 99 and the first electrode 98 are formed is separated into 200 μm square light emitting chips using the cleavage of the p-type GaAs substrate 911, and the nitride semiconductor having the structure as shown in FIG. A light emitting element 91 is obtained.

By manufacturing a nitride semiconductor light emitting element as in Patent Document 1, a structure in which electrodes can be taken out from both the upper and lower directions of a p-type GaAs substrate 911 and a more compact nitride semiconductor light emitting element 91 is realized. It is now possible to do.
Japanese Patent No. 3511970 Japanese Patent No. 3893874

  However, in the nitride semiconductor light emitting device 91 manufactured by the method disclosed in Patent Document 1, the PN junction portion is exposed at the end of the chip, so that the first pasted metal layer 931 and the second pasted metal layer 932 There is a problem in that a part of the metal used protrudes from the end portion of the chip and further wraps around to short-circuit the PN junction portion, resulting in poor yield.

  Further, when silver paste is used as the metal used for the first adhesive metal layer 931 and the second adhesive metal layer 932 to which the p-type GaAs substrate 911 is attached, leakage occurs due to long-term aging even if there is no problem in the initial characteristics. There is a problem that the current gradually increases and the light extraction efficiency gradually decreases. The cause of the increase in the leakage current is presumed to be due to the leakage of the silver paste used for the first pasted metal layer 931 described above.

  Therefore, in order to solve the above problem, in Patent Document 2, as shown in FIG. 11, the bonding layer 103, the p-side ohmic layer 106, the insulating layer 105, and the p-type nitride semiconductor layer are formed on the conductive substrate 102. 1043, a light emitting layer 1042, a first n-type nitride semiconductor layer 1041 and an n-side ohmic electrode 108 in this order are disclosed.

  According to the method for manufacturing a nitride semiconductor light emitting device described in Patent Document 2, since the p-layer side dividing groove is provided at the position where the chip is divided and the PN junction is covered with the insulating layer 105, the chip division is performed. In this case, it is possible to prevent the end face leakage at the PN junction. However, in this method for manufacturing a nitride semiconductor light emitting device, since the bonding layer 103 is formed by thermocompression bonding after forming the p-layer side dividing groove, the metal of the bonding layer adheres to the side surface of the p-layer side dividing groove, There was a problem that the light extraction efficiency was lowered.

  Therefore, the present invention has been made in view of the above-described problems, and the nitride semiconductor light emitting device of the present invention has a reduced PN junction short circuit and current leakage, and has a light extraction efficiency. An object of the present invention is to provide a nitride semiconductor light emitting device that is high, has a high manufacturing yield, and is highly reliable, and a method for manufacturing the same.

  That is, the nitride semiconductor light emitting device of the present invention is a nitride semiconductor light emitting device including a conductive substrate, a bonding layer, and a nitride semiconductor layer in this order, and is provided between the bonding layer and the nitride semiconductor layer. Further has an insulating layer, and the outer peripheral portion of the surface of the nitride semiconductor layer on the bonding layer side is in contact with the surface of the insulating layer.

  Further, an electrode layer is further included between the insulating layer and the nitride semiconductor layer, and the insulating layer includes a part of the surface of the electrode layer on the bonding layer side, the side surface of the electrode layer, and the nitride semiconductor layer. The nitride semiconductor light emitting device is in contact with the outer peripheral portion of the surface in contact with the electrode layer.

  The nitride semiconductor layer includes at least a p-type nitride semiconductor layer, a light emitting layer, and a first n-type nitride semiconductor layer in this order from the conductive substrate side.

  The nitride semiconductor layer includes at least a second n-type nitride semiconductor layer, a p-type nitride semiconductor layer, a light emitting layer, and a first n-type nitride semiconductor layer in this order from the conductive substrate side. It is characterized by including.

  The outer periphery of the nitride semiconductor layer is preferably smaller than the outer periphery of the insulating layer, and more preferably smaller than the outer periphery of the conductive substrate.

  In addition, the thickness of the insulating layer is preferably a thickness that can withstand as an etching stop layer in the step of removing the nitride semiconductor layer by etching to expose the insulating layer.

The side surface of the nitride semiconductor layer is preferably tapered.
The surface of the first n-type nitride semiconductor layer on the side opposite to the side in contact with the light emitting layer preferably has an uneven shape.

  Moreover, it is preferable that the said electrode layer contains the contact | adherence protective layer for maintaining the adhesiveness with the said insulating layer in the surface of the side in contact with the said insulating layer.

  Moreover, it is preferable that the said joining layer contains a 1st sticking metal layer and a 2nd sticking metal layer, and this 2nd sticking metal layer contains the 1st ohmic layer used as an ohmic contact with an electroconductive board | substrate.

  The bonding layer preferably includes one or both of a first eutectic bonding layer and a second eutectic bonding layer.

  The bonding layer preferably includes an adhesion layer for maintaining adhesion to the insulating layer on a surface in contact with the insulating layer.

The bonding layer preferably includes a plating base layer.
In the method for manufacturing a nitride semiconductor light emitting device of the present invention, the first n-type nitride semiconductor layer, the light emitting layer, and the p-type nitride semiconductor layer are stacked in this order on the first substrate (A). When,
A step (B) of forming an insulating layer on the surface of the p-type nitride semiconductor layer;
Removing part of the insulating layer to expose a part of the surface of the electrode layer in contact with the insulating layer (C);
A step (D) of laminating a bonding layer and a conductive substrate in this order over the entire surface of the insulating layer;
Removing part or all of the first substrate (E);
And a step (F) of obtaining a plurality of nitride semiconductor light emitting devices by dividing the chip obtained by the steps (A) to (E).

  Moreover, it is preferable to include the process (A1) of laminating | stacking a 2nd n-type nitride semiconductor layer between the said process (A) and a process (B).

  Moreover, before performing the said process (B), it is preferable to perform the process (G) which laminates | stacks an electrode layer.

  Further, it is preferable to include a step (H) between the step (E) and the step (F), in which the nitride semiconductor layer is removed so as to expose the insulating layer, and a chip dividing groove is formed.

  Moreover, it is preferable to include the process (J) of removing a part of 1st n-type nitride semiconductor layer between the said process (E) and a process (H).

  Moreover, before performing the said process (F), it may include the process (I) which removes a part of 1st n-type nitride semiconductor layer and forms surface unevenness | corrugation in the said 1st n-type nitride semiconductor layer. preferable.

  In the step (E), part or all of the first substrate is preferably removed by laser light irradiation.

  In the step (F), the position where the chip is divided is preferably any position of the chip dividing groove.

  In the step (I), the surface irregularities of the first n-type nitride semiconductor layer are preferably formed by etching.

  In the step (H), the insulating layer preferably functions as an etching stop layer.

  Moreover, in the said process (D), the lamination | stacking of the said electroconductive board | substrate joins the 1st eutectic joining layer contained in the said joining layer, and the 2nd eutectic joining layer formed on the said electroconductive board | substrate. Is preferably performed.

  In the step (D), the conductive substrate is preferably laminated by a plating method.

  In the step (C), the electrode layer preferably functions as an etching stop layer.

  According to the nitride semiconductor light emitting device and the method for manufacturing the same of the present invention, the nitride semiconductor light emitting device has high light extraction efficiency, high manufacturing yield in the substrate pasting step and peeling step, and high reliability. And a method for manufacturing the same. That is, since the nitride semiconductor light emitting device of the present invention does not have a nitride semiconductor layer in the chip division region, a source of leakage current due to metal entrapment or the like in a process of forming a nitride semiconductor light emitting device wafer into a chip or the like Generation can be reduced, and the yield can be improved. In addition, it is possible to provide a highly reliable nitride semiconductor light emitting device that is less deteriorated even when a long-term energization or a large current is applied.

Hereinafter, the present invention will be described in detail with reference to Embodiments 1 and 2.
(Embodiment 1: Nitride semiconductor light emitting device)
FIG. 1 is a schematic cross-sectional view of a nitride semiconductor light emitting device 1 according to a preferred embodiment 1 of the present invention. As shown in FIG. 1, the nitride semiconductor light emitting device 1 of Embodiment 1 includes a second electrode 9, a conductive substrate 2, a bonding layer 3, an insulating layer 5, an electrode layer 6, and current blocking. It includes a layer 7, p-type nitride semiconductor layers 43 and 44, a light emitting layer 42, a first n-type nitride semiconductor layer 41, and a first electrode 8 in this order. The insulating layer 5 is in contact with a part of the surface of the electrode layer 6 on the bonding layer 3 side, the entire side surface of the electrode layer 6, and the outer periphery of the p-type nitride semiconductor layer 44 on the bonding layer 3 side. It is characterized by that.

  The feature of the nitride semiconductor light emitting device 1 of the present invention is that the outer peripheral portion of the surface of the p-type nitride semiconductor layer 44 is in contact with the surface of the insulating layer 5, as shown in FIG. By adopting such a structure, the outer peripheral portion of the surface of the insulating layer 5 becomes the chip end portion of the nitride semiconductor light emitting element 1, and even after the chip is divided, end face leakage does not occur and the yield can be improved. In addition, even when energized for a long period of time, metal wraparound at the PN junction is not recognized, and the highly reliable nitride semiconductor light emitting device 1 can be provided. Hereinafter, each layer of the nitride semiconductor light emitting device 1 will be described with reference to FIG.

<Conductive substrate>
The conductive substrate 2 included in the nitride semiconductor light emitting device 1 of the present invention is preferably made of a material such as metal, alloy, Si, GaP, GaAs, SiC, or conductive diamond.

<Junction layer>
The bonding layer 3 included in the nitride semiconductor light emitting device 1 of the present invention is in contact with the conductive substrate 2 and is located on the side opposite to the p-type nitride semiconductor layers 43 and 44 when viewed from the insulating layer 5. Is a layer. The bonding substrate 3 bonds the conductive substrate 2 and the nitride semiconductor layer 4 together.

  The bonding layer 3 included in the nitride semiconductor light emitting device 1 of the present invention is a layer composed of a first adhesive metal layer 31 and a second adhesive metal layer 32. Here, the first pasted metal layer 31 included in the nitride semiconductor light emitting device 1 of the present invention is a surface on the opposite side to the surface on which the nitride semiconductor layer 4 is formed, of the upper and lower surfaces of the insulating layer 5. In other words, the layer includes the adhesion layer 33, the first diffusion prevention layer 34, and the first eutectic bonding layer 35. Further, the second adhesive metal layer 32 is a layer formed on one surface of the conductive substrate 2 and includes the second eutectic bonding layer 36, the second diffusion prevention layer 37, and the first ohmic layer 38. .

  The nitride semiconductor light emitting element 1 of the present invention has a eutectic bonding attaching step of obtaining a nitride semiconductor wafer by attaching the first attaching metal layer 31 and the second attaching metal layer 32. This eutectic bonding step is performed by bringing the first eutectic bonding layer 35 and the second eutectic bonding layer 36 into contact with each other and thermocompression bonding. Below, each layer contained in the 1st sticking metal layer 31 and the 2nd sticking metal layer 32 is demonstrated in detail.

(I) Adhesion layer The adhesion layer 33 included in the first adhesive metal layer 31 of the present invention is for improving the adhesion strength between the first eutectic bonding layer 35 or the first diffusion prevention layer 34 and the insulating layer 5. Is a layer. Depending on the type of metal used for the first eutectic bonding layer 35 and the first diffusion prevention layer 34, it may be difficult to adhere to the insulating layer 5, and in such a case, film peeling occurs on the surface of the insulating layer 5. As a result, the reliability of the nitride semiconductor light emitting device may deteriorate. However, by providing the adhesion layer 33 as in the present invention, it is possible to improve the adhesion between the insulating layer 5 and the first pasting metal layer 31, so that the above problem can be effectively prevented. A nitride semiconductor light emitting device with higher reliability can be provided.

  As the metal or alloy used for the adhesion layer 33, for example, NiTi, Ti, Ni, W, TiW, Pt, Mo, Nb, Ta or the like can be preferably used. The adhesion layer 33 is not limited to a single layer structure, and may have a multilayer structure. In addition, the thickness of the adhesion layer is not particularly limited, and a thickness usually used in the field can be adopted, for example, a thickness of about 5 to 500 nm.

(Ii) First Diffusion Prevention Layer The first diffusion prevention layer 34 included in the first adhesive metal layer 31 of the present invention is a layer for preventing metal diffusion. By providing this layer, it is possible to prevent the metal contained in the electrode layer 6 from diffusing into the metal in the adhesion layer 33 to prevent a decrease in the bonding strength, and the reflection layer including the metal contained in the adhesion layer 33 in the electrode layer 6. It is possible to prevent the reflectance of the reflective layer 61 from being lowered due to diffusion to 61. Furthermore, by providing the first diffusion preventing layer 34, it is possible to prevent the metal from diffusing into the nitride semiconductor layer 4 and thus to deteriorate the device characteristics, and to further improve the reliability of the nitride semiconductor light emitting device. .

  Here, as the metal or alloy used for the first diffusion preventing layer 34, conventionally known ones can be adopted, and for example, a group consisting of Ti, Ni, W, Mo, Nb, Ta, NiTi, Pt, and the like. At least one selected from the above can be used. Further, the thickness of the first diffusion preventing layer 34 is not particularly limited, and a thickness usually used in the field can be adopted, and for example, can be about 50 to 500 nm.

(Iii) First Eutectic Bonding Layer The first eutectic bonding layer 35 included in the first adhesive metal layer 31 of the present invention is a layer for maintaining the adhesive strength between the conductive substrate 2 and the nitride semiconductor layer 4. is there. By providing the first eutectic bonding layer 35, a more reliable nitride semiconductor light emitting device can be provided.

  Here, as a material used for the first eutectic bonding layer 35, a conventionally known material can be adopted as long as it is a metal or an alloy containing a eutectic bonding metal, for example, Au, AuSn, AuGe, AuSi, an alloy of Ag, Pd, and Cu can be suitably used. The first eutectic bonding layer 35 is not limited to a single layer structure, and may be a multilayer structure. For example, in the case of a multilayer structure, for example, an Au layer and an AuSn layer A two-layer structure can be mentioned. The thickness of the eutectic bonding layer is not particularly limited, and a thickness usually used in the field can be employed, and can be, for example, about 50 to 3000 nm.

(Iv) Second Eutectic Bonding Layer The second eutectic bonding layer 36 included in the second adhesive metal layer 32 of the present invention is a layer for maintaining the adhesive strength between the conductive substrate 2 and the nitride semiconductor layer 4. Thus, it is a layer bonded to the surface of the first eutectic bonding layer 35 described above. The material, layer structure, and layer thickness used for the second eutectic bonding layer 36 can be appropriately selected from the same materials, layer structure, and layer thickness used for the first eutectic bonding layer 35 described above. .

(V) Second Diffusion Prevention Layer The second diffusion prevention layer 37 included in the second adhesive metal layer 32 of the present invention is a layer provided for the same purpose as the first diffusion prevention layer 34, and this second diffusion prevention layer. The material, layer structure, and layer thickness used for the layer 37 can be appropriately selected from the same materials, layer structure, and layer thickness used for the first diffusion prevention layer 34 described above.

(Vi) First Ohmic Layer The first ohmic layer 38 included in the second adhesive metal layer 32 of the present invention is a layer in which the conductive substrate 2 and the bonding layer 3 are in ohmic contact, and is a nitride semiconductor light emitting device This is a layer for reducing the driving voltage. As the material used for the first ohmic layer 38, a conventionally known material can be adopted as long as it is a metal, an alloy, or a conductive oxide. For example, Ti, Au, Al, or an alloy thereof, ITO, or the like can be used. Can be used.

  The first ohmic layer 38 is not limited to a single layer structure, and may be a multilayer structure. Examples of the multilayer structure include a two-layer structure of a Ti layer and an Au layer. it can. The thickness of the first ohmic layer 38 is not particularly limited, and a thickness usually used in the field can be adopted, and for example, can be about 1 to 5000 nm.

<Insulating layer>
The insulating layer 5 included in the nitride semiconductor light emitting device 1 of the present invention is a layer located between the bonding layer 3 and the nitride semiconductor layer 4. In the nitride semiconductor light emitting device of the present invention, the outer peripheral portion of the p-type nitride semiconductor layer 44 is in contact with the surface of the insulating layer 5, and the outer peripheral portion of the insulating layer 5 is the chip end of the nitride semiconductor light emitting device. It is characterized by that.

  In the conventional nitride semiconductor light emitting device, the outer peripheral portion of the nitride semiconductor layer 4 is not in contact with the surface of the insulating layer 5, and the electrode layer 6 is formed up to the end face region. For this reason, when the nitride semiconductor layer 4 is dry-etched to form a chip dividing groove 13 which will be described later, the etching proceeds to the electrode layer 6 and the metal used for the electrode layer 6 scatters and adheres to the PN junction. There was a problem that end face leakage occurred. However, if the outer peripheral portion of the insulating layer 5 is a chip end portion of the nitride semiconductor light emitting element 1 as in the present invention, the electrode layer 6 is not etched when the chip dividing groove 13 is formed, It is possible to effectively prevent end face leakage.

  Further, when the insulating layer 5 is not provided between the electrode layer 6 and the bonding layer 3, the reflective layer included in the electrode layer 6 when heat is applied during the manufacturing process or when aging is performed for a long period of time. There is a problem that the metal 61 diffuses into the bonding layer 3 to reduce the reflectance of the reflective layer 61 and the light extraction efficiency decreases. However, by providing the insulating layer 5 between the electrode layer 6 and the bonding layer 3 as in the structure of the present invention, it is possible to prevent the material of the electrode layer 6 and the material of the bonding layer 3 from diffusing each other. The light extraction efficiency can be made difficult to decrease.

  The p-type nitride semiconductor layer 44 and the insulating layer 5 have an area in contact with the surface of the p-type nitride semiconductor layer 44 on the side in contact with the insulating layer 5. The area in contact with the insulating layer 5 is preferably 1 to 50%, and more preferably 1 to 20%. If the area is larger than 50%, the current is difficult to be injected into the region where the insulating layer 5 and the p-type nitride semiconductor layer 44 are in contact with each other. Since there is a possibility, it is not preferable. Further, when the area is less than 1%, in the step of partially removing the insulating layer 5 formed on the entire surface of the p-type nitride semiconductor layer 44, which will be described later, by etching or the like, alignment failure occurs and yield decreases. This is not preferable because of the tendency.

Here, the material used for the insulating layer 5 may be any material as long as it has insulating properties. For example, SiO ₂ , SiN, Si ₃ N ₄ , HfO ₂ , TiO ₂ , Al ₂ O ₃ , HfLaO, HfAlO, LaAlO and the like can be preferably used. Moreover, SiO ₂ and SiN are particularly preferably used from the viewpoint of easy film formation control.

The insulating layer 5 is preferably thick enough to withstand the etching stop layer in the step of removing the nitride semiconductor layer 4 by etching and exposing the insulating layer 5. However, since the thickness that can withstand this etching stop layer varies depending on the material, it is difficult to clearly define the range of the film thickness. Therefore, for example, when the range of film thickness when SiO ₂ is used as the material of the insulating layer is defined, the layer thickness is preferably in the range of 0.1 to 3 μm. The insulating layer 5 is not limited to a single layer, and may have a multilayer structure.

Here, the “thickness enough to withstand as an etching stop layer” will be described more specifically. For example, the nitride semiconductor layer 4 made of GaN having a thickness of 6 μm has a variation in the thickness of 5.8 to 6.2 μm. Therefore, when the nitride semiconductor layer 4 is dry-etched using a chlorine-based gas to form the chip dividing groove 13, the thickness of 6.2 μm is used to completely eliminate the nitride semiconductor layer 4 remaining. The thickness must be removed by etching. At this time, the minimum thickness portion of the nitride semiconductor layer is excessively etched by about 0.4 μm. Incidentally, since this underlying nitride semiconductor layer when used for the insulating layer 5 made of SiO _2, SiO ₂ etching rate is about 1 / 6-1 / 4 as compared to GaN etching rate, if the etching Assuming that the rate is 1/4, when the nitride semiconductor layer is excessively etched by about 0.4 μm as described above, when converted to the insulating layer 5, SiO having a thickness of 0.1 μm is removed. . Therefore, when SiO ₂ is used for the insulating layer 5, a thickness of at least 0.1 μm is required in order to have a thickness that can withstand as an etching stop layer.

Here, if the layer thickness of the insulating layer 5 made of SiO ₂ is less than 0.1 μm, the metal used for the first pasting metal layer 31 under the insulating layer is scattered by etching and sticks to the PN junction, causing end face leakage. It is not preferable because it is generated. Further, if the thickness of the insulating layer 5 is larger than 3 μm, it is not preferable because a problem that the material cost is excessive and a problem that heat dissipation is lowered occur.

<Electrode layer>
As shown in FIG. 1, the electrode layer 6 included in the nitride semiconductor light emitting device 1 of the present invention is located on the p-type nitride semiconductor layer 44 side as viewed from the insulating layer 5. The protective layer 62 includes at least one layer. Hereinafter, the reflective layer 61 and the adhesion protective layer 62 will be described.

(I) Reflective layer The reflective layer 61 included in the electrode layer 6 of the present invention is a layer having a high reflectance with respect to the main emission wavelength of the light emitting layer 42. By providing this layer, the light extraction efficiency of the nitride semiconductor light emitting device 1 can be improved. That is, the light emitted from the light emitting layer 42 passes through the first n-type nitride semiconductor layer 41 and is directly emitted to the outside of the nitride semiconductor layer 4 and once emitted to the electrode layer 6 side to reflect the reflective layer 61. Since the light extraction efficiency can be improved by increasing the total of these lights, the light extraction efficiency can also be improved by increasing the reflection layer 61. Can be improved. Note that “having a high reflectance” means having a reflectance of about 70 to 100% with respect to the main emission wavelength of the nitride semiconductor light emitting device. The reflective layer has a single layer structure or a multilayer structure of metal or alloy.

  Here, examples of the metal or alloy having high reflectivity with respect to the main emission wavelength of the nitride semiconductor light emitting device include Ag, AgNd, AgPd, AgCu, Al, AgBi, APC (Ag, Pd, Cu alloy), and the like. AgNd, Ag, AgBi, and APC can be particularly preferably used from the viewpoint of a material having a high reflectivity of about 90% with respect to light having a main emission wavelength of 450 nm.

  The thickness of the reflective layer 61 is not particularly limited, and a thickness usually used in the field can be adopted, and for example, can be about 50 to 1000 nm.

(Ii) Adhesion Protection Layer The adhesion protection layer 62 included in the electrode layer 6 of the present invention is a layer containing a metal, alloy, or conductive oxide that is in ohmic contact with the p-type nitride semiconductor layers 43 and 44. By providing the adhesion protective layer 62, the electrode layer 6 and the p-type nitride semiconductor layer 44 form an ohmic junction, and the driving voltage of the nitride semiconductor light emitting element 1 can be reduced. Further, the adhesion protective layer 62 is not limited to a single layer structure, and may have a multilayer structure.

  Here, as a material used for the adhesion protective layer 62, conventionally known metals, alloys, or conductive oxides can be employed. For example, Ag, AgNd, AgPd, AgCu, Al, AgBi, APC (Ag) , Pd, Cu alloy), ITO, IZO, indium oxide, zinc oxide, transparent conductive film, Pd, Ni, Mo, Au, Fe, Cu, Zn, Mg, Ti, W, Ta, etc. Can be used.

  Since the optimum thickness of the adhesion protective layer 62 differs depending on the reflectance and transmittance of the material, it is difficult to specify the range by specific numerical values. If the thickness range is specified, the thickness may be 0.5 to 5000 nm. For example, when a material having low reflectance and low transmittance is used, the layer thickness is preferably about 0.5 to 10 nm. On the other hand, when a material having a low reflectance but a high transmittance such as ITO is used, the layer thickness is preferably about 10 to 5000 nm. Further, when a material having a high reflectance is used, the thickness is not particularly limited. Note that the reflective layer 61 may also serve as the adhesion protective layer 62.

<Current blocking layer>
The nitride semiconductor light-emitting device 1 of the present invention is on the surface of the p-type nitride semiconductor layers 43 and 44 on the side opposite to the light-emitting layer 42 side and directly below the position where the first electrode 8 is installed. A current blocking layer 7 is formed at the position. By providing the current blocking layer 7 at this position, current can be efficiently injected into the light emitting region, and a light emitting element with high light emitting efficiency can be obtained.

That is, in the structure of the nitride semiconductor light emitting element, for example, when an opaque thick film metal layer or the like is used for the first electrode 8, even if the light emitting layer 42 emits light directly under the first electrode 8. The light cannot be extracted from the portion, and the light is lost. However, if the current blocking layer 7 is provided immediately below the first electrode 8, the light emitting layer 42 does not emit light immediately below the position where the first electrode 8 is installed, so that the loss of light can be eliminated. A light-emitting element with luminous efficiency can be obtained. As a material used for the current blocking layer 7, a conventionally known material such as Ti, SiO ₂ or the like can be used, or a part of the surface of the p-type nitride semiconductor layer 44 is subjected to high resistance by plasma treatment. It can also be formed by a method to make it.

  The nitride semiconductor light emitting device of the present invention has a hole formed in the vicinity of the center of the insulating layer 5 in order to establish electrical connection between the bonding layer 3 and the electrode layer 6, and is included in the electrode layer 6 through this hole. There is a problem in that the metal diffuses into the bonding layer 3 and the reflectivity of the reflective layer 61 of the electrode layer 6 decreases, thereby reducing the light extraction efficiency. However, even if the current blocking layer 7 is provided directly above the hole near the center of the insulating layer 5 as in the present invention, even if the reflectance of the reflective layer 61 diffuses and the reflectance of the reflective layer 61 decreases. Since the region directly below the current blocking layer 7 does not emit light, it is possible to prevent the light extraction efficiency from being lowered.

  The hole formed in the vicinity of the center of the insulating layer 5 is preferably accommodated in the region where the current blocking layer 7 is formed. Even in the region where the bonding layer 3 and the electrode layer 6 are in contact with each other, even if the metal of the bonding layer 3 diffuses into the electrode layer 6 and the reflectance of the reflective layer 61 of the electrode layer 6 decreases, this portion is the current blocking layer 7. If there is, light is not emitted, and thus the reflectance itself is not a problem, and the light extraction efficiency is not lowered.

<Second n-type nitride semiconductor layer>
A second n-type nitride semiconductor layer (not shown) may be provided between the p-type nitride semiconductor layer 44 and the insulating layer 5 of the nitride semiconductor light emitting device 1 of the present invention. Since this layer serves as a current diffusion layer, the provision of this layer has the advantage that the electrode layer 6 need not be provided in the nitride semiconductor light emitting device 1.

  That is, as is widely known, the p-type nitride semiconductor layers 43 and 44 have a very high specific resistance. Therefore, when a current is injected into the p-type nitride semiconductor layers 43 and 44, the p-type nitride semiconductor layers 43 and 44 have a specific resistance. In the nitride semiconductor layer, the current does not spread in the horizontal direction but only flows in the vertical direction, so that the current flows only in the light emitting layer 42 in the vicinity of the electrode layer 6 in the region where the electrode layer 6 is formed. The entire surface could not emit light.

  However, if the second n-type nitride semiconductor layer is provided under the p-type nitride semiconductor layer, the specific resistance of the n-type nitride semiconductor is relatively low. The current can be spread in the lateral direction, so that the current flows over the entire area where the second n-type nitride semiconductor layer is formed, and the current can be injected into the light emitting layer 42 in a wider range. Further, n-type GaN can be used as a material used for the second n-type nitride semiconductor layer. Moreover, the thickness of this layer is not specifically limited, For example, it can be 5-1000 nm.

<P-type nitride semiconductor layer>
The p-type nitride semiconductor layers 43 and 44 included in the nitride semiconductor light emitting device 1 of the present invention are layers composed of a p-type AlGaN layer and a p-type GaN layer. The thicknesses of the p-type AlGaN layer and the p-type GaN layer are not particularly limited, and can be, for example, 10 to 100 nm and 50 to 1000 nm, respectively.

<Light emitting layer>
The light emitting layer 42 included in the nitride semiconductor light emitting device 1 of the present invention is a layer including a barrier layer made of GaN and a well layer made of In _q Ga _{1 -q} N (0 <q <1). The thicknesses of the barrier layer and the well layer are not particularly limited, and can be 3 to 30 nm and 0.5 to 5 nm, for example.

<First n-type nitride semiconductor layer>
The first n-type nitride semiconductor layer 41 included in the nitride semiconductor light emitting device 1 of the present invention is a layer made of n-type GaN and having a light extraction surface. Here, the light extraction surface refers to a surface opposite to the surface in contact with the light emitting layer 42 among the surfaces other than the side surface of the first n-type nitride semiconductor layer 41.

  The light extraction surface of the first n-type nitride semiconductor layer preferably has an uneven shape. The irregular shape may be regular or random, but when regular, for example, the irregularity has a pitch of about 100 to 5000 nm and a depth of about 0.2 to 10 μm. Is preferred.

  By thus forming surface irregularities on the light extraction surface of the first n-type nitride semiconductor layer 41, it is possible to effectively prevent a decrease in light extraction efficiency due to multiple reflection inside the nitride semiconductor layer 4. Therefore, the light extraction efficiency can be further improved. In addition, when the light extraction surface is a p-type nitride semiconductor layer as in a conventional nitride semiconductor light emitting device, the layer thickness is about 100 to 800 nm. There was a problem that it was difficult to form. However, in the nitride semiconductor light emitting device 1 of the present invention, since the first n-type nitride semiconductor layer 41 is a light extraction surface, the layer thickness is about several μm, and thus it is easy to form such surface irregularities. There is an advantage.

  Further, the surface irregularities can be formed by patterning by dry etching or wet etching, and can also be formed by laser light irradiation, polishing, or the like. In addition, the surface of the first n-type nitride semiconductor layer 41 on the side in contact with the first substrate 10 can form surface irregularities naturally without using the above-described method. Further, in the nitride semiconductor light emitting device 1 of the present invention, the crystal plane on which the unevenness is formed is exposed also in the tapered portion of the chip dividing groove 13, and the light is further increased by forming the unevenness in this portion. The extraction efficiency can be improved.

  As a method for improving the light extraction efficiency by forming irregularities other than the above method, the first n-type nitride semiconductor layer is left by leaving a part of the first substrate when the first substrate is removed by laser light. There is also a method of forming an uneven surface shape on 41. According to this method, it is possible to form an uneven shape having a depth of about several tens of μm.

  The composition of the materials used for the first n-type nitride semiconductor layer 41, the light emitting layer 42, the p-type nitride semiconductor layers 43 and 44, and the second n-type nitride semiconductor layer is not limited to the above description. For example, AlInGaN can be used. Further, the thickness of the first n-type nitride semiconductor layer 41 is not particularly limited, and may be, for example, 2 to 10 μm.

<Chip dividing groove>
In the present invention, the nitride semiconductor light emitting device 1 has a chip dividing groove 13 for dividing the chip. That is, the end face of the nitride semiconductor layer 4 and the end face of the insulating layer 5, the bonding layer 3, and the conductive substrate 2 do not exist in the same plane, and only the end face of the nitride semiconductor layer 4 is the nitride semiconductor light emitting element. It is structured to be inside. Furthermore, the outer periphery of the nitride semiconductor layer 4 is smaller than the outer periphery of the insulating layer 5 and further smaller than the outer periphery of the conductive substrate 2. By adopting such a structure, it is possible to prevent a short circuit at the PN junction.

  The distance between the outer periphery of the nitride semiconductor layer 4 and the outer periphery of the insulating layer 5 or the like is preferably 3 to 30 μm. If the distance is less than 3 μm, the PN junction is burnt by a slight misalignment when the chip is divided by laser scribing, which is not preferable. In addition, when the distance is larger than 30 μm, the area of the light emitting portion itself becomes narrow, which is not preferable because the light emission efficiency is lowered.

<First electrode and second electrode>
As shown in FIG. 1, the first electrode 8 and the second electrode 9 included in the nitride semiconductor light-emitting device 1 of the present invention are first connected for external connection formed on the first n-type nitride semiconductor layer 41. One electrode 8 and a second electrode 9 for external connection formed on the surface opposite to the bonding layer 3 side of the conductive substrate 2 are provided.

  As described above, the nitride semiconductor light emitting device 1 according to the present embodiment enables the electrodes to be taken out from the top and bottom of the chip even though the insulating layer 5 is provided in the device. Thus, by forming the external connection electrodes on the upper and lower surfaces of the chip, not only the chip can be miniaturized, but also the chip can be easily handled during mounting, and the mounting yield can be improved.

  As a material used for the first electrode 8 and the second electrode 9, a conventionally known material can be adopted, and for example, Ti, Al, or the like can be used. Moreover, the 1st electrode 8 and the 2nd electrode 9 are not restricted to a single layer structure, A multilayer structure can also be taken. The layer thickness of the first electrode 8 is preferably 200 to 5000 nm from the viewpoint of obtaining good wire bondability, and the layer thickness of the second electrode 9 is an electrode if a film is formed as a whole. Therefore, the layer thickness may be relatively thin as compared with the first electrode 8, and the thickness is preferably about 100 to 5000 nm.

<Side of nitride semiconductor layer>
Further, as shown in FIG. 1, the side surfaces of the p-type nitride semiconductor layers 43 and 44, the light emitting layer 42 and the first n-type nitride semiconductor layer 41 included in the nitride semiconductor layer 4 of the present embodiment are Both have a tapered structure in the vicinity of the element end. That is, the area of each layer gradually increases from the first n-type nitride semiconductor layer 41 toward the p-type nitride semiconductor layer 44.

  In addition, the uneven shape provided in the first n-type nitride semiconductor layer 41 is preferably formed also in the tapered structure portion of the nitride semiconductor layer 4. By adopting a structure in which the side surface of the nitride semiconductor layer 4 has a concavo-convex shape in this manner, the light extraction efficiency at the element end can be improved.

<Nitride Semiconductor Light-Emitting Device Manufacturing Method>
Next, a preferred method for manufacturing the nitride semiconductor light-emitting element 1 of the first embodiment will be described in detail with reference to the embodiments 1-1 to 1-6 with reference to FIGS. 2-7 is sectional drawing which shows the general | schematic process which shows a preferable example of the manufacturing method of this invention.

(Embodiment 1-1)
The nitride semiconductor light emitting device 1 manufactured according to the embodiment 1-1 is
A step of stacking a first n-type nitride semiconductor layer, a light emitting layer, and a p-type nitride semiconductor layer on the first substrate in this order (hereinafter referred to as “step (A)”);
A step of forming an insulating layer on the surface of the p-type nitride semiconductor layer (hereinafter referred to as “step (B)”);
Removing a part of the insulating layer to expose a part of the surface of the electrode layer in contact with the insulating layer (hereinafter referred to as “process (C)”);
A step of laminating a bonding layer and a conductive substrate in this order on the entire surface of the insulating layer (hereinafter referred to as “step (D)”);
A step of peeling a part or all of the first substrate (hereinafter referred to as “step (E)”);
And a step of obtaining a plurality of nitride semiconductor light emitting devices by dividing the chip obtained by the steps (A) to (E) (hereinafter referred to as “step (F)”).
Each process (A)-(F) is demonstrated in detail below.

<Process (A)>
First, the step (A) in the manufacturing process of the nitride semiconductor light emitting device of the present embodiment is performed on the first substrate 10 using a sapphire substrate as shown in FIG. The buffer layer 12 made of Al _r Ga _1-r N (0 ≦ r ≦ 1) is formed by means usually used in the above, and then the first n-type nitride semiconductor layer 41, which is an n-type GaN layer, is formed from GaN. A light emitting layer 42 including a barrier layer and a well layer made of In _q Ga _1-q N (0 <q <1), and p-type nitride semiconductor layers 43 and 44 made of a p-type AlGaN layer and a p-type GaN layer. It is a process of growing in order.

<Process (B)>
Next, in the step (B), as shown in FIG. 3, the insulating layer 5 is entirely provided on the surface of the p-type nitride semiconductor layer 44 formed by the above-described step (A) or the electrode layer 6 is present. This is a step of forming the electrode layer 6 on the entire surface of the electrode layer 6, the entire side surface of the electrode layer 6, and the surface of the p-type nitride semiconductor layer 44 where the electrode layer 6 is not formed.

  If the insulating layer 5 is not formed at this position in the nitride semiconductor light emitting device 1 of the present invention, the nitride semiconductor layer 4 is used for the bonding layer 3 by dry etching when the chip dividing groove 13 is formed by dry etching. There is a problem that the metal that has been scattered scatters and adheres to the PN junction, causing end face leakage. However, by providing the insulating layer 5 between the bonding layer 3 and the nitride semiconductor layer 4 as in the present invention, the insulating layer 5 functions as an etching stop layer, so that the bonding layer 3 is prevented from being exposed during etching. Therefore, it is possible to effectively prevent the metal of the bonding layer 3 from scattering and adhering to the PN junction and causing end face leakage.

<Process (C)>
Next, in the step (C), as shown in FIG. 3, a part of the insulating layer 5 formed on the surface of the electrode layer 6 is removed by etching, and the surface of the electrode layer 6 in contact with the insulating layer 5 is removed. This is a step of exposing a part.

  As a method for exposing a part of the surface of the electrode layer 6, for example, wet etching or dry etching can be employed as long as the etching is performed using a photoresist mask. However, from the viewpoint of causing the electrode layer 6 therebelow to function as an etching stop layer, it is preferable to use a hydrofluoric acid-based etchant as the etchant when performing wet etching, and the reaction gas when performing dry etching is as follows. It is preferable to use a fluorine-based gas.

<Process (D)>
Next, the step (D) is a step of laminating the bonding layer 3 and the conductive substrate 2 in this order on the insulating layer 5 and the exposed electrode layer 6 as shown in FIG. 4B. In this step (D), first, as shown in FIG. 4 (b), on the insulating layer 5 and the exposed electrode layer 6, the adhesion layer 33 included in the first adhesive metal layer 31, the first diffusion prevention The layer 34 and the first eutectic bonding layer 35 are formed in this order by sputtering or vapor deposition. On the other hand, as shown in FIG. 4A, the first ohmic layer 38 included in the second adhesive metal layer 32 is formed on the conductive substrate 2 such as a Si substrate by means usually used in the art. After the second diffusion preventing layer 37 and the second eutectic bonding layer 36 are formed, the first eutectic bonding layer 35 and the second eutectic bonding layer 36 are brought into contact with each other, and bonded by thermocompression bonding in a reduced pressure atmosphere. Thus, the bonding layer 3 is formed. It is preferable that the degree of pressure reduction during the joining is 10 Pa or less. By setting the atmosphere in a reduced pressure in this way, generation of voids can be suppressed.

In addition, for example, when the Au layer and the AuSn layer are bonded, the bonding temperature is preferably 280 to 400 ° C., and more preferably 300 to 350 ° C. from the viewpoint of improving adhesion. The bonding pressure can be 10 to 300 N / cm ² .

  The formation of the second eutectic bonding layer 36 on the conductive substrate 2 may be performed at any timing before the formation of the first eutectic bonding layer 35 is completed. The formation of the crystal bonding layer 35 may be performed simultaneously with or after the completion.

<Process (E)>
Next, as shown in FIG. 5, the step (E) is performed by irradiating a laser beam P of, for example, 355 nm or 266 nm from the side of the first substrate 10 where the nitride semiconductor layer 4 is not formed. This is a step of removing the first substrate 10 by decomposing all or most of the layers and a part of the first n-type nitride semiconductor layer 41.

  In the nitride semiconductor light emitting device disclosed in Patent Document 2, since the chip dividing groove is formed before the first substrate is peeled and the insulating layer is formed in the chip dividing groove, the first substrate and the insulating layer 5 are formed. It has a contact part. However, since the insulating layer does not absorb the laser beam, there is a problem that the portion where the insulating layer 5 and the first substrate 10 are in contact cannot be separated by the laser beam. However, since the first substrate 10 and the nitride semiconductor layer 4 are in contact with each other in the nitride semiconductor light emitting device 1 of the present invention, there is no portion where the first substrate 10 and the insulating layer 5 are in contact. The first substrate 10 can be easily peeled off.

  Although all or most of the first substrate 10 and the buffer layer are removed by the irradiation with the laser beam P, the light extraction efficiency can also be improved by forming a convex portion by leaving a part of the first substrate 10. Can be improved.

  After this step (E), it is preferable to provide a step (H) in which a part of the nitride semiconductor layer 4 is removed and the chip dividing groove 13 is formed so that the surface of the insulating layer 5 is exposed. Further, the surface of the first n-type nitride semiconductor layer 41 is etched with a strong alkaline solution such as KOH or tetramethylammonium to remove a part of the first n-type nitride semiconductor layer 41, and the first It is preferable to provide the step (I) of forming surface irregularities on the n-type nitride semiconductor layer 41. Step (H) and step (I) will be described in Embodiments 1-4 and 1-5.

<Process (F)>
Finally, as shown in FIG. 7, at any position of the chip dividing groove 13 where the insulating layer is exposed at a constant pitch (the dotted line in FIG. 7 indicates the most preferable position), the nitride semiconductor A wafer of light emitting elements is divided into chips.

  As the dividing method, a diamond scribe method, a dicing method, a laser scribe method, or the like can be used. As described above, the nitride semiconductor light emitting element of Embodiment 1-1 can be manufactured.

(Embodiment 1-2)
In the embodiment 1-2, in addition to the step (A) of the embodiment 1-1, after the p-type nitride semiconductor layer 44 is laminated, a second n-type nitride semiconductor layer is further laminated (hereinafter referred to as the step (A)). And “step (A1)”). The step (A1) will be described below.

<Process (A1)>
In the step (A1), the buffer layer 12, the first n-type nitride semiconductor layer 41, the light emitting layer 42, and the p-type nitride semiconductor layers 43 and 44 are grown in this order on the first substrate 10 by the step (A). Then, a second n-type nitride semiconductor layer is further grown on the p-type nitride semiconductor layers 43 and 44.

  The nitride of the embodiment 1-2 is obtained by using the same manufacturing method as that of the embodiment 1-1 except that (A1) is added after the step (A) of the embodiment 1-1. A semiconductor light emitting device can be manufactured.

(Embodiment 1-3)
In Embodiment 1-3, a step of forming electrode layer 6 on the exposed surface of p-type nitride semiconductor layer 44 (hereinafter referred to as “step (G)”) is added before performing step (B). It is characterized by. Hereinafter, the step (G) will be described.

<Process (G)>
As shown in FIG. 2, after the p-type nitride semiconductor layer 44 is stacked in the step (A) of the first embodiment 1-1 or the second n-type nitridation in the step (A1) of the first embodiment 1-2. After the physical semiconductor layer is stacked, the electrode layer 6 including the reflective layer 61 and the adhesion protective layer 62 is formed on the p-type nitride semiconductor layer 44 or the second n-type nitride semiconductor layer by vapor deposition.

  When the electrode layer 6 is provided on the p-type nitride semiconductor layer by this step, the first electrode 8 is on the surface of the p-type nitride semiconductor layers 43 and 44 opposite to the light emitting layer 42 side. It is desirable that the current blocking layer 7 be formed at a position that is approximately directly below the position where the is installed. In forming the current blocking layer 7, a method of partially increasing the resistance of a part of the surface of the p-type nitride semiconductor layer 44 by plasma treatment or the like can be used.

  Further, after providing the electrode layer as described above, a substantially square photoresist mask is formed at a constant pitch, and the reflective layer 61 and the adhesion protective layer 62 that are not covered with the photoresist are removed by etching or the like. To do. The reflective layer 61 is heat-treated to lower the contact resistance and improve the adhesion with the p-type nitride semiconductor layer 44. Further, the adhesion protective layer 62 is also a layer for maintaining adhesion with the insulating layer 5 formed in the next step (C).

  The electrode layer 6 in Embodiment 1-3 may have a configuration in which the reflective layer 61 and the adhesion protective layer 62 are made of different materials or the same material.

  The same as Embodiment 1-1 except that the step (G) of forming the electrode layer 6 on the exposed surface of the layer laminated on the p-type nitride semiconductor layer 44 is included before performing the step (B). By using this manufacturing method, the nitride semiconductor light emitting device of Embodiment 1-3 can be manufactured.

(Embodiment 1-4)
In the embodiment 1-4, the insulating layer 5 is formed on the exposed surface of the nitride semiconductor layer 4 at substantially regular intervals between the step (E) and the step (F) of the embodiment 1-1. A nitride semiconductor light emitting device is manufactured by adding a step of removing the nitride semiconductor layer 4 (hereinafter referred to as “step (H)”) so that the chip dividing groove 13 having a depth to be exposed is formed. The The step (H) will be described below.

<Process (H)>
As shown in FIG. 6, the surface of the nitride semiconductor layer 4 is dry-etched at a substantially constant interval to remove a part of the nitride semiconductor layer 4 so that the surface of the insulating layer 5 is exposed. A groove 13 is formed. By this step (H), the portion of the nitride semiconductor layer 4 including the first n-type nitride semiconductor layer 41, the light emitting layer 42, and the p-type nitride semiconductor layers 43 and 44 is interrupted at a constant pitch. In this chip dividing groove 13, the chip is divided by the subsequent step (F).

  In the nitride semiconductor light emitting device 1 according to the present invention, since the insulating layer 5 is provided between the nitride semiconductor layer 4 and the bonding layer 3, the insulating layer functions as an etching stop layer. The chip dividing grooves 13 can be formed after 10 peeling steps (E).

  In the conventional method for manufacturing a nitride semiconductor light emitting device, the chip dividing groove is not formed, or even if the chip dividing groove is formed, a part of the nitride semiconductor layer remains on the substrate in a connected state. When the chip is divided by scribing, there is a problem that the PN junction is burnt and the light extraction efficiency is lowered. However, by forming the chip dividing groove 13 so that the insulating layer 5 is exposed as in the nitride semiconductor light emitting device of the present invention, the nitride semiconductor layer can be effectively prevented from being burned, and the light extraction efficiency can be reduced. It became possible to suppress the decline of.

  In addition, in the conventional method for manufacturing a nitride semiconductor light emitting device, when the chip dividing groove is formed by dry etching, there is no etching stop layer, so that the metal used for the first and second affixed metal layers is scattered. As a result, there is a problem in that it is attached to the PN junction and causes a short circuit. However, in the present invention, by forming the insulating layer 5 to the extent that it functions as an etching stop layer, it is effective that the metal used for the first adhesive metal layer and the second adhesive metal layer scatters and adheres to the PN junction. Thus, the occurrence of end face leakage at the PN junction can be reduced as much as possible.

  Further, the chip dividing groove 13 is formed in a region where the insulating layer 5 is in contact with the p-type nitride semiconductor layer 44. By doing so, no metal adheres to the PN junction, so that the PN junction is not short-circuited. Further, as shown in the nitride semiconductor light emitting device of Patent Document 2, the PN junction portion is not covered with the insulating layer 5 and the metal, so that the light extraction efficiency is not lowered.

  Further, in the conventional method of manufacturing a nitride semiconductor light emitting device, after forming the chip dividing groove, an insulating layer is formed thereon, and then the first and second adhesive metal layers are attached. In the manufacturing process, the first substrate is then peeled off. However, this manufacturing process has the following two problems.

The first problem in the manufacturing process of the conventional nitride semiconductor light emitting device is that the interface between the nitride semiconductor layer and the insulating layer is flat, so that the light reaching the end face is reflected again into the crystal, Is a problem that it cannot be efficiently taken out of the device. That is, for example, the refractive index of the insulating layer made of SiO ₂ is 1.5, the refractive index of the nitride semiconductor layer made of GaN is 2.4, and the refractive index difference between the two is large. When the interface between the insulating layer and the insulating layer is flat, reflection tends to occur at the interface, making it difficult to extract light to the outside. However, as in the present invention, if the chip dividing groove is formed after the first substrate is peeled off and the nitride semiconductor layer crystal is formed on the surface, the surface of the nitride semiconductor layer 4 and the tapered side surface are uneven. Therefore, even if the refractive index difference between the nitride semiconductor layer 4 and the insulating layer 5 is large, light can be extracted to the outside while being irregularly reflected by the unevenness, thereby improving the light extraction efficiency. be able to.

  Another problem of the conventional nitride semiconductor light-emitting device is that, after the chip dividing groove is formed, the first bonding metal layer and the second bonding metal layer are bonded to the chip dividing groove. This is a problem that the metal of the pasted metal layer is embedded. For this reason, there is a problem that the reflectance at the end of the chip is lowered and the light extraction efficiency is lowered. As a method for solving this problem, Patent Document 2 discloses a technique for preventing the chip dividing groove from being filled with metal by increasing the width of the chip dividing groove. If the width is increased, the area of the wafer that emits light itself becomes narrow, and the light extraction efficiency decreases.

  Therefore, the nitride semiconductor light emitting device of the present invention forms the chip dividing grooves 13 by etching after the first bonding metal layer 31 and the second bonding metal layer 32 are bonded, so Since the metal of the 1st sticking metal layer 31 and the 2nd sticking metal layer 32 is not embedded, the reflectance fall in a chip | tip edge part can be prevented effectively, and it can improve the extraction efficiency of light.

  As described above, the nitride semiconductor light emitting device of the embodiment 1-4 can be manufactured by adding the step (H) between the step (E) and the step (F) of the embodiment 1-1. it can.

Embodiment 1-5
In Embodiment 1-5, after the step (E) or the step (H), a part of the first n-type nitride semiconductor layer is removed, and surface irregularities are formed on the first n-type nitride semiconductor layer. The step of forming (hereinafter referred to as step (I)) is added. Step (I) will be described below.

<Process (I)>
As shown in FIG. 7, the surface of the first n-type nitride semiconductor layer 41 is etched with a strong alkaline solution such as KOH or tetramethylammonium, so that a part of the first n-type nitride semiconductor layer 41 is formed. While removing, surface irregularities are formed on the first n-type nitride semiconductor layer 41. By forming the surface irregularities on the first n-type nitride semiconductor layer 41, light is scattered and the light extraction efficiency is improved.

  Here, by performing this step (I) after forming the chip dividing groove 13, irregularities can also be formed in the tapered shape of the side surface of the nitride semiconductor layer 4 in the vicinity of the chip dividing groove 13, Furthermore, the light extraction efficiency can be improved.

  Further, after the first substrate 10 is removed by laser light irradiation in the step (E), a damaged layer is generated on the exposed surface of the first n-type nitride semiconductor layer 41, and this damaged layer absorbs light. As a result, the light extraction efficiency is reduced. However, this damaged layer is removed by etching the surface of the first n-type nitride semiconductor layer 41 with KOH or tetramethylammonium in this step (I), and the light extraction efficiency can be improved.

  Conversely, if the surface irregularities are formed in the first n-type nitride semiconductor layer 41 by this step (I) before the step (H) of forming the chip dividing grooves 13 in the nitride semiconductor layer 4, Thereafter, when the chip dividing groove 13 is formed on the surface of the first n-type nitride semiconductor layer 41 by dry etching, the etching rate becomes unstable, and there is a problem that etching cannot be performed uniformly on the entire surface of the wafer. Absent.

  Further, if surface irregularities are formed in the first n-type nitride semiconductor layer 41, the transparent nitride semiconductor layer becomes opaque, and therefore the electrode layer 6 is formed in the photolithography process for forming the chip dividing grooves 13. It is difficult to perform alignment so as to form a chip dividing groove in a portion that is not present, and it is not preferable from the viewpoint that it is difficult to form the chip dividing groove at an appropriate position.

  Further, not only the surface of the first n-type nitride semiconductor layer 41 but also the step (I) of performing etching such as KOH after the step (H) of forming the chip dividing groove 13 in the nitride semiconductor layer 4 is performed. Irregularities are also formed on the side surfaces of the tapered nitride semiconductor layer 4 located in the chip dividing grooves 13, so that the light extraction efficiency can be improved.

  The nitride semiconductor of the embodiment 1-5 is the same as the embodiment 1-1 except that the step (I) is added after the step (E) of the embodiment 1-1. A light emitting element can be manufactured.

Embodiment 1-6
Embodiment 1-6 is the same as Embodiment 1-4 in that a part of the first n-type nitride semiconductor layer is removed between step (E) and step (H) (hereinafter referred to as step). (J)) is added to manufacture a nitride semiconductor light emitting device. Hereinafter, the step (J) will be described.

<Process (J)>
The step (J) is a step of removing a part of the first n-type nitride semiconductor layer 41 between the step (E) and the step (H). Here, it is preferable to etch the first n-type nitride semiconductor layer 41 approximately uniformly at a depth of about 1 μm from the buffer layer side. This is because a damage layer containing a lot of damage is formed in the first n-type nitride semiconductor layer in the vicinity of the interface where the first substrate is peeled off by irradiating the laser beam, and this damage layer absorbs light. As a result, the light extraction efficiency is reduced. However, the light extraction efficiency can be improved by removing the damaged layer by etching in this step.

  In addition, the n-type nitride semiconductor layer 41 in the vicinity of the buffer layer 12 is a crystal layer at the initial growth stage when the crystal is grown on the first substrate 10, and therefore originally has poor crystal quality and many impurity levels. It was an absorption layer. By removing the portion by etching or the like, a portion that causes light absorption can be removed, and light extraction efficiency can be increased.

  Here, the depth for removing the first n-type nitride semiconductor layer is preferably about 0.5 to 3 μm, more preferably about 1 μm from the buffer layer side. Moreover, it is more preferable to etch substantially uniformly. If the depth at which the first n-type nitride semiconductor layer is removed is less than 0.5 μm, it is not preferable because a damaged layer may remain, and the first n-type nitride semiconductor layer is deeper than 3 μm. If is removed, there is a problem that it becomes difficult to form surface irregularities in the subsequent step (I) and a problem that current is difficult to spread, which is not preferable.

The step (J) is preferably performed before the step (H) for forming the chip dividing grooves.
This is because the insulating layer is exposed on the bottom surface of the chip dividing groove, and the insulating layer may be slightly etched by the dry etching in the step (J), and the underlying metal layer may be exposed.

(Embodiment 2: Nitride semiconductor light emitting device)
FIG. 8 is a schematic cross-sectional view showing a nitride semiconductor light emitting device 81 according to another preferred embodiment 2 of the present invention. The nitride semiconductor light emitting device 81 of the present embodiment includes a conductive substrate 82, a bonding layer 83, an insulating layer 85, an electrode layer 86, p-type nitride semiconductor layers 843 and 844, a light emitting layer 842, The first n-type nitride semiconductor layer 841 in this order. The insulating layer 85 includes a part of the surface of the electrode layer 86 on the bonding layer 83 side, the entire side surface of the electrode layer 86, and the bonding layer 83. The p-type nitride semiconductor layer 844 on the side is in contact with the outer peripheral portion.

  The nitride semiconductor light emitting device of this embodiment has an advantage in that a conductive substrate can be directly introduced into the device by using a material capable of forming a layer by plating on the conductive substrate 82.

  Further, the nitride semiconductor light emitting device 81 of the second embodiment has the first electrode 88 on the first n-type nitride semiconductor layer 841. Further, the conductive substrate 82 itself becomes a second electrode for external connection.

  Here, in the nitride semiconductor light emitting device 81 of the second embodiment, the p-type nitride semiconductor layers 843 and 844 are composed of a p-type AlGaN layer and a p-type GaN layer. The bonding layer 83 includes a plating base layer.

  Thus, if the outer peripheral portion of the surface of the p-type nitride semiconductor layer 844 is in contact with the surface of the insulating layer 85, the outer peripheral portion of the surface of the insulating layer 85 becomes the chip end portion, and end face leakage does not occur, yield. Will improve. In addition, even when energized for a long period of time, metal sneak around at the PN junction is not recognized, and a highly reliable nitride semiconductor light emitting device 81 can be provided.

  Hereinafter, only the characteristic part of the second embodiment will be described, but the points not described are the same as those of the first embodiment.

<Conductive substrate>
In the nitride semiconductor light emitting device 81 of the second embodiment, the conductive substrate 82 is made of a material capable of forming a layer by plating. As such a material, for example, a metal or an alloy containing Ni, Cu, Sn, Au, or Ag as a main component can be used.

  The thickness of the conductive substrate 82 can be set to 20 to 300 μm, for example, but the thickness of the conductive substrate 82 is preferably set to 50 to 300 μm from the viewpoint of easy handling of the chip.

<Junction layer>
The bonding layer 83 in the second embodiment includes an adhesion layer and a plating underlayer. Hereinafter, the plating base layer will be described.

(I) Plating Underlayer A conductive substrate 82 is formed with high yield by providing a plating underlayer on the bonding layer 83 of the nitride semiconductor light emitting device 81 of the present invention and plating the conductive substrate 82 through this. be able to. Here, as the metal or alloy constituting the plating underlayer, conventionally known ones can be employed, and examples thereof include Au, Ni, Pd, Cu, and alloys containing these. Further, the thickness of the plating base layer is not particularly limited, and a thickness usually used in the field can be employed, and can be, for example, about 10 to 5000 nm.

  Various modifications may be made to nitride semiconductor light emitting element 81 of the second embodiment as long as it does not depart from the scope of the present invention. For example, the bonding layer 83 may include not only the plating base layer but also the first diffusion prevention layer and the adhesion layer as in the first embodiment. Other modifications are the same as those of the nitride semiconductor light emitting device 1 of the first embodiment.

<Nitride Semiconductor Light-Emitting Device Manufacturing Method>
(Embodiment 2-1)
Next, a preferred method for manufacturing the nitride semiconductor light emitting device 81 of the second embodiment will be described in the present embodiment 2-1. Of the manufacturing method of nitride semiconductor light emitting device 81 of the embodiment 2-1, the process up to step (C) is the same as the manufacturing method of nitride semiconductor light emitting device 1 of the embodiment 1-1. Step (D-1) and subsequent steps will be described.

In the manufacturing method of the nitride semiconductor light emitting device of the embodiment 2-1, after the step (C) of the embodiment 1-1, a plating base layer is formed as a bonding layer on the entire surface of the insulating layer, and the conductivity is increased. A step of forming a substrate by plating (hereinafter referred to as “step (D-1)”);
A step of removing a part or all of the first substrate (hereinafter referred to as “step (E)”);
And a step of obtaining a plurality of nitride semiconductor light emitting devices by dividing the chip obtained in the step (E) (hereinafter referred to as “step (F)”).

  The steps (D-1) and (F) that are partially different from those of the embodiment 1-1 will be described below with reference to FIG.

<Process (D-1)>
In the step (D-1), an adhesion layer as a bonding layer 83 and a plating base layer are formed in this order on the insulating layer 85 and the exposed electrode layer 86, and further, the conductive substrate 82 is formed by plating. To do. The plating method may be electroless plating or electrolytic plating.

<Process (F)>
Next, the chip division in the step (F) is preferably division by laser scribing. This is because diamond scribe or dicing may be inappropriate when a highly viscous material is used for the conductive substrate 82.

Example 1
The nitride semiconductor light emitting device 1 of Example 1 was fabricated by the following method. This will be schematically described with reference to FIGS.

<Process (A)>
First, as shown in FIG. 2, on a first substrate 10 made of sapphire, a buffer layer 12 made of Al _r Ga _1-r N (0 ≦ r ≦ 1) having a thickness of 50 nm, an n-type having a thickness of 5 μm. A light emitting layer 42 having a thickness of 100 nm, including a first n-type nitride semiconductor layer 41 made of a GaN layer, a barrier layer made of GaN, and a well layer made of In _q Ga _1-q N (0 <q <1), P-type nitride semiconductor layers 43 and 44 made of a p-type AlGaN layer having a thickness of 30 nm and a p-type GaN layer having a thickness of 200 nm were grown in this order. Next, a photoresist mask having openings of 100 μmφ is formed at a pitch of 400 μm, the surface of the p-type nitride semiconductor layer 44 is exposed to plasma containing Ar gas for 30 seconds, and the resistance is increased by increasing the resistance. Formed.

<Process (G)>
Next, as shown in FIG. 2, an Ag layer is formed as the reflective layer 61 as the electrode layer 6 with a thickness of 300 nm on the entire surface of the p-type nitride semiconductor layer 44, and a Ti layer is formed as the adhesion protective layer 62 with a thickness of 10 nm. Was formed by vapor deposition. Next, alignment is performed so that the current blocking layer 7 is arranged at the center of a square having a side of 320 μm, a photoresist mask is formed at a pitch of 400 μm, and then exposed with an etching solution in which acetic acid and nitric acid are mixed. The portion of the electrode layer 6 that has been etched was etched.

<Process (B)>
Next, after removing the photoresist, a SiO ₂ layer was formed as the insulating layer 5 so as to cover the entire surface, that is, the surface of the electrode layer 6, the side surface of the electrode layer 6, and the surface of the p-type nitride semiconductor layer 44.

<Process (C)>
Next, as shown in FIG. 3, a part of the insulating layer 5 formed on the surface of the electrode layer 6 is removed by etching so that the surface of the electrode layer 6 is within the range of the current blocking layer 7. A part was exposed.

<Process (D)>
Next, as shown in FIG. 4B, a Ti layer having a thickness of 100 nm is formed as the adhesion layer 33 on the insulating layer 5 and the exposed electrode layer 6, and further, Pt is formed as the first diffusion prevention layer 34. A layer was formed by sputtering with a thickness of 100 nm, and finally an Au layer was deposited as a first eutectic bonding layer 35 with a thickness of 1 μm to form a first stuck metal layer 31.

  Next, as shown in FIG. 4A, a Ti layer having a thickness of 10 nm is formed as the first ohmic layer 38 on the conductive substrate 2 which is a Si substrate, and then the second diffusion preventing layer 37 is formed. An Au layer having a thickness of 200 nm was formed, and an AuSn layer having a thickness of 1 μm was deposited as the second eutectic bonding layer 36. Then, the first eutectic bonding layer 35 and the second eutectic bonding layer 36 were brought into contact with each other and bonded by thermocompression bonding.

<Process (E)>
Next, as shown in FIG. 5, a laser beam P of 355 nm is irradiated from the back surface of the first substrate 10 to form a buffer layer (not shown) and a part of the first n-type nitride semiconductor layer 41. And the first substrate 10 was removed.

  Next, the entire surface of the first n-type nitride semiconductor layer 41 exposed by removing the first substrate 10 was removed by about 1 μm by dry etching.

<Process (H)>
Next, as shown in FIG. 6, an approximately square photoresist mask having a side of 340 μm is formed at a pitch of 400 μm, and a portion of the first n-type nitride semiconductor layer 41 that is not covered with the photoresist mask, the light emitting layer 42 and the p-type nitride semiconductor layers 43 and 44 were removed by dry etching to expose the insulating layer 5, and the chip dividing grooves 13 were formed. Here, the approximately square photoresist mask of 340 μm was aligned so that the approximately square electrode layer 6 having a side of 320 μm fits inside.

<Process (I)>
Next, as shown in FIG. 7, after removing the photoresist mask, surface irregularities were formed in the first n-type nitride semiconductor layer 41 by etching with KOH. Since the chip split groove 13 was formed in the step (H) and etching with KOH was performed, irregularities were also formed in the PN junction, and the light extraction efficiency could be further improved.

  Next, a Ti layer having a thickness of 15 nm and an Al layer having a thickness of 100 nm were formed by vapor deposition as the first electrode 8 for external connection near the center of the surface of the first n-type nitride semiconductor layer 41. Further, on the surface opposite to the first electrode 8, a Ti layer having a thickness of 15 nm and an Al layer having a thickness of 200 nm are formed by vapor deposition as the second electrode 9 for external connection, and the structure shown in FIG. A wafer was obtained. The first electrode 8 for external connection was formed almost directly above the current blocking layer 7. By doing so, no current is injected directly under the opaque first electrode 8, so that no light is emitted and no unnecessary light emission is generated, so that the light extraction efficiency can be improved.

<Process (F)>
Finally, as shown in FIG. 7, the wafer is divided into chips by a laser scribing method at the portion where the insulating layer 5 is exposed at a pitch of 400 μm (the position of the dotted line in FIG. 7), and nitride A semiconductor light emitting device 1 was obtained.
Example 2
<Process (A)>
In the method of manufacturing the nitride semiconductor light emitting device 201 according to the second embodiment, as shown in FIG. 9, first, an Al _r Ga _1-r N having a thickness of 50 nm is formed on a first substrate (not shown) made of sapphire. (0 ≦ r ≦ 1) buffer layer (not shown), first n-type nitride semiconductor layer 241 made of 5 μm-thick n-type GaN layer, barrier layer made of GaN, and In _q Ga _1-q N A light emitting layer 242 having a thickness of 100 nm, a p-type nitride semiconductor layer 243 comprising a p-type AlGaN layer having a thickness of 30 nm and a p-type GaN layer having a thickness of 200 nm, including a well layer made of (0 <q <1). 244 were grown in this order.

<Process (A1)>
Further, a second n-type nitride semiconductor layer 245 made of an n-type GaN layer having a thickness of 200 nm was grown on the p-type nitride semiconductor layer 244.

<Process (B)>
Next, a photoresist mask having openings of 100 μmφ is formed at a pitch of 400 μm, the second n-type nitride semiconductor layer 245 in the openings is removed by dry etching, and then the p-type nitride semiconductor layers 243 and 244 are further formed. Halfway was removed by etching.

<Process (C)>
Next, an insulating layer 205 made of SiO ₂ is formed on the entire surface, and a portion of the insulating layer 205 in the region where the second n-type nitride semiconductor layer 245 other than the 100 μmφ opening is present is removed by etching using a photoresist mask. Thus, the second n-type nitride semiconductor layer 245 was exposed. At this time, the insulating layer 205 made of SiO _{2 can} be etched either by wet etching using a chemical solution containing hydrofluoric acid or by dry etching using a gas containing fluorine gas (for example, CHF ₃ ). The type nitride semiconductor layer 245 functions as a good etching stop layer. Further, a region where the region where the p-type nitride semiconductor layers 243 and 244 are exposed is covered with SiO ₂ functions as the current blocking layer 207. In this embodiment, the current blocking layer is etched up to the p-type nitride semiconductor layer 243 and covered with the SiO ₂ layer, but is etched up to the first n-type nitride semiconductor layer 241 and covered therewith with SiO ₂ . The same effect can be obtained.

<Process (D)>
Next, a Ti layer is formed as an adhesion layer 233 with a thickness of 100 nm on the insulating layer 205 and the exposed second n-type nitride semiconductor layer 245, and a Pt layer is formed as a first diffusion prevention layer 234 with a thickness of 100 nm. Then, an Au layer was deposited as a first eutectic bonding layer 235 with a thickness of 1 μm to form a first pasted metal layer 231.

  Here, since the adhesion layer 233 made of a Ti layer also serves as an electrode layer, a current is injected in a region in contact with the second n-type nitride semiconductor layer 245, and the second n-type nitride semiconductor layer 245. Thus, the current is diffused, and the current can be injected into the light emitting layer 242 other than the region where the current blocking layer 207 is formed.

  Next, a Ti layer having a thickness of 10 nm is formed as the first ohmic layer 238 on the conductive substrate 202 that is a Si substrate, and then a Pt layer having a thickness of 100 nm is formed as the second diffusion preventing layer 237. After an Au layer having a thickness of 200 nm was formed, an AuSn layer having a thickness of 1 μm was vapor-deposited thereon as the second eutectic bonding layer 236 to form a second adhesive metal layer 232. Then, the first eutectic bonding layer 235 and the second eutectic bonding layer 236 were in contact with each other and bonded by thermocompression bonding, whereby the bonding layer 203 was formed.

<Process (E)>
Next, the first substrate was removed by irradiating a laser beam of 355 nm from the back surface of the first substrate to decompose a part of the buffer layer and the first n-type nitride semiconductor layer 241. The subsequent steps are the same as in the first embodiment.

  This embodiment is characterized in that no electrode layer is formed between the insulating layer 205 and the nitride semiconductor layer 204. This is possible because the second n-type nitride semiconductor layer 245 serves as a current diffusion layer and the adhesion layer 233 serves as an electrode layer.

In Example 1, the contact area between the insulating layer and the p-type nitride semiconductor layer was preferably 1 to 50%, but the contact area between the insulating layer in Example 2 and the second n-type nitride semiconductor layer was preferred. Is preferably 1 to 99%. Because the second n-type nitride semiconductor layer has a small specific resistance even when the contact area is 50% or more, the current can easily spread in the second n-type nitride semiconductor layer. This is because the efficiency is not lowered.
Example 3
A method for manufacturing the nitride semiconductor light emitting device 81 will be described with reference to FIG.

<Process (A to C)>
The same procedure as in Example 1 was performed until the formation of the insulating layer 85 in the step (C). That is, a nitride semiconductor layer 84 including a first n-type nitride semiconductor layer 841, a light emitting layer 842, and p-type nitride semiconductor layers 843 and 844 is formed on a first substrate (not shown), and then After the current blocking layer 87 was formed, an electrode layer 86 and an insulating layer 85 composed of the reflective layer 861 and the adhesion protective layer 862 were formed.

<Process (D-1)>
After the step (C), an Au layer having a thickness of 200 nm was formed by vapor deposition as a plating base layer, and a Cu layer having a thickness of 100 μm was formed as the conductive substrate 82 using an electrolytic plating method.

<Process (E)>
Next, a laser beam P of 355 nm was irradiated from the back surface of the first substrate 10 to decompose a part of the buffer layer and the first n-type nitride semiconductor layer 841 to remove the first substrate. After the step (E), the nitride semiconductor light emitting device of Example 3 was obtained by the same procedure as in Example 1.

  In this embodiment, the conductive substrate 82 is made of a material capable of forming a layer by plating. Thus, using the material which can form a layer by plating for the electroconductive board | substrate 82 has the merit that the process of joining a 1st eutectic joining layer and a 2nd eutectic joining layer can be skipped.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the nitride semiconductor light emitting device and the method for manufacturing the same of the present invention, it is possible to provide a nitride semiconductor light emitting device having high light extraction efficiency and high manufacturing yield in substrate pasting and peeling processes.

It is typical sectional drawing which shows an example of the nitride semiconductor light-emitting device. It is typical sectional drawing which shows the nitride semiconductor light-emitting device after the manufacturing process (G) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows the nitride semiconductor light-emitting device after the manufacturing process (C) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows the process of bonding the layer (a) containing a conductive substrate, and the layer (b) containing a nitride semiconductor layer in the manufacturing process (D) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows the process of peeling an electroconductive board | substrate in the manufacturing process (E) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows the process of forming a chip | tip division | segmentation groove | channel in a nitride semiconductor layer in the manufacturing process (H) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows the process divided | segmented into a chip | tip in the manufacturing process (F) of a nitride semiconductor light-emitting device. It is typical sectional drawing which shows an example of the nitride semiconductor light-emitting device. It is typical sectional drawing which shows an example of the nitride semiconductor light-emitting device. 1 is a schematic cross-sectional view showing a nitride semiconductor light emitting element described in Patent Document 1. FIG. 6 is a schematic cross-sectional view showing a nitride semiconductor light emitting device described in Patent Document 2. FIG.

Explanation of symbols

  1,81,91,201 Nitride semiconductor light emitting device, 2,82,102,202 Conductive substrate, 3,83,103,203 Junction layer, 4,84,94,204 Nitride semiconductor layer, 5,85, 105,205 insulating layer, 6,86 electrode layer, 7,87,207 current blocking layer, 8,88,98,208 first electrode, 9,99,209 second electrode, 10 first substrate, 12 buffer layer, 13 Chip Dividing Groove, 31,231,931 First Attached Metal Layer, 32,232,932 Second Attached Metal Layer, 33,233 Adhesive Layer, 34,234 First Diffusion Prevention Layer, 35,235 First Eutectic Bonding Layer, 36, 236 second eutectic bonding layer, 37, 237 second diffusion prevention layer, 38, 238 first ohmic layer, 41, 241, 841, 941, 1041 first n-type nitride semiconductor layer, 42, 24 , 842, 942, 1042 Light emitting layer, 43, 44, 243, 244, 843, 844, 943, 1043 p-type nitride semiconductor layer, 61,861 reflective layer, 62,862 adhesion protective layer, 106 p-side ohmic layer, 108 n-side ohmic electrode, 245 second n-type nitride semiconductor layer, 911 p-type GaAs substrate, P laser light.

Claims (27)

  A nitride semiconductor light emitting device including a conductive substrate, a bonding layer, and a nitride semiconductor layer in this order, further comprising an insulating layer between the bonding layer and the nitride semiconductor layer, The nitride semiconductor light emitting element, wherein an outer peripheral portion of the surface of the nitride semiconductor layer on the bonding layer side is in contact with the surface.   An electrode layer is further included between the insulating layer and the nitride semiconductor layer, and the insulating layer includes a part of a surface of the electrode layer on the bonding layer side, a side surface of the electrode layer, and the nitride semiconductor layer. The nitride semiconductor light-emitting element according to claim 1, wherein the nitride semiconductor light-emitting element is in contact with an outer peripheral portion of a surface on the side in contact with the electrode layer.   3. The nitride semiconductor layer includes at least a p-type nitride semiconductor layer, a light emitting layer, and a first n-type nitride semiconductor layer in this order from the conductive substrate side. The nitride semiconductor light-emitting device according to 1.   The nitride semiconductor layer includes at least a second n-type nitride semiconductor layer, a p-type nitride semiconductor layer, a light emitting layer, and a first n-type nitride semiconductor layer in this order from the conductive substrate side. The nitride semiconductor light-emitting device according to claim 1.   5. The nitride semiconductor light emitting device according to claim 1, wherein an outer periphery of the nitride semiconductor layer is smaller than an outer periphery of the insulating layer.   6. The nitride semiconductor light emitting device according to claim 1, wherein an outer periphery of the nitride semiconductor layer is smaller than an outer periphery of the conductive substrate.   The thickness of the insulating layer is a thickness that can withstand as an etching stop layer in the step of removing the nitride semiconductor layer by etching to expose the insulating layer. The nitride semiconductor light-emitting device according to 1.   The nitride semiconductor light emitting device according to claim 1, wherein a side surface of the nitride semiconductor layer has a tapered shape.   9. The nitride semiconductor according to claim 3, wherein a surface of the first n-type nitride semiconductor layer on a side opposite to a side in contact with the light emitting layer has an uneven shape. Light emitting element.   The nitride semiconductor light emitting device according to claim 2, wherein the electrode layer includes an adhesion protective layer for maintaining adhesion to the insulating layer on a surface in contact with the insulating layer. element. The bonding layer includes a first adhesive metal layer and a second adhesive metal layer,
The nitride semiconductor light emitting element according to claim 1, wherein the second adhesive metal layer includes a first ohmic layer that is in ohmic contact with the conductive substrate.   The nitride semiconductor light emitting element according to claim 1, wherein the bonding layer includes one or both of a first eutectic bonding layer and a second eutectic bonding layer.   The nitride semiconductor light emitting element according to claim 1, wherein the bonding layer includes an adhesion layer for maintaining adhesion to the insulating layer on a surface in contact with the insulating layer. .   The nitride semiconductor light emitting device according to claim 1, wherein the bonding layer includes a plating base layer. A step (A) of laminating a first n-type nitride semiconductor layer, a light emitting layer, and a p-type nitride semiconductor layer in this order on a first substrate;
Forming an insulating layer on the surface of the p-type nitride semiconductor layer (B);
Removing a part of the insulating layer to expose a part of the surface of the electrode layer in contact with the insulating layer (C);
A step (D) of laminating a bonding layer and a conductive substrate in this order over the entire surface of the insulating layer;
Removing part or all of the first substrate (E);
And a step (F) of obtaining a plurality of nitride semiconductor light emitting devices by dividing the chip obtained by the steps (A) to (E).   The nitride semiconductor light emitting device according to claim 15, further comprising a step (A1) of laminating a second n-type nitride semiconductor layer between the step (A) and the step (B). Production method.   The method for manufacturing a nitride semiconductor light emitting element according to claim 15, wherein a step (G) of laminating an electrode layer is performed before performing the step (B).   A step (H) of removing a nitride semiconductor layer so as to expose the insulating layer and forming a chip dividing groove is included between the step (E) and the step (F). Item 18. A method for producing a nitride semiconductor light emitting device according to any one of Items 15 to 17.   The nitride semiconductor according to claim 18, further comprising a step (J) of removing a part of the first n-type nitride semiconductor layer between the step (E) and the step (H). Manufacturing method of light emitting element.   Before performing the step (F), the method includes a step (I) of removing a part of the first n-type nitride semiconductor layer and forming surface irregularities on the first n-type nitride semiconductor layer. The manufacturing method of the nitride semiconductor light-emitting device according to any one of claims 15 to 19.   21. The method of manufacturing a nitride semiconductor light emitting element according to claim 15, wherein in the step (E), part or all of the first substrate is removed by laser light irradiation.   The method for manufacturing a nitride semiconductor light emitting element according to any one of claims 18 to 21, wherein, in the step (F), a position where the chip is divided is any position of the chip dividing groove.   23. The method of manufacturing a nitride semiconductor light-emitting element according to claim 20, wherein in the step (I), the surface irregularities of the first n-type nitride semiconductor layer are formed by etching. .   The method for manufacturing a nitride semiconductor light emitting element according to any one of claims 18 to 23, wherein in the step (H), the insulating layer functions as an etching stop layer.   In the step (D), the conductive substrate is laminated by bonding a first eutectic bonding layer included in the bonding layer and a second eutectic bonding layer formed on the conductive substrate. The method for producing a nitride semiconductor light emitting device according to any one of claims 15 to 24, which is performed.   26. The method for manufacturing a nitride semiconductor light-emitting element according to claim 15, wherein in the step (D), the conductive substrate is stacked by a plating method.   27. The method for manufacturing a nitride semiconductor light-emitting element according to claim 15, wherein in the step (C), the electrode layer functions as an etching stop layer.

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