JP6755230B2 - Nitride semiconductor light emitting device and method for manufacturing nitride semiconductor light emitting device - Google Patents

Description

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

Semiconductors are now an indispensable part of everyday life. In the field of lighting, light emitting diodes (LEDs), which are a type of semiconductor device, are replacing conventional fluorescent lamps and incandescent lamps. In addition, many people know that LEDs are used as backlights for liquid crystal display panels of televisions, personal computers, mobile phones, etc., and traffic signals.

There are various types of semiconductors used for LEDs, but recently, nitride semiconductors represented by GaN, AlN, InN and their mixed crystals have been attracting attention. Since the nitride semiconductor has a larger bandgap Eg than the AlGaInAs-based semiconductor and the AlGaInP-based semiconductor and is a direct transition type, it can emit light in a wide wavelength region from ultraviolet light to green light. Nitride semiconductors can be used for semiconductor laser devices that output light of various wavelengths, LEDs that can cover a wide emission wavelength range from ultraviolet light to red light, and the like by taking advantage of these characteristics.

Nitride semiconductor light emitting devices using nitride semiconductors have a wide emission wavelength range, and are therefore considered to be applied to projectors and full-color displays. In addition, taking advantage of the ability to shorten the emission wavelength, expectations are rising for its application to the public health and environmental fields such as sterilization, water purification, and high-speed decomposition of pollutants, as well as to various medical fields. Along with this, research and development of semiconductor light emitting devices that emit light in the deep ultraviolet region (wavelength: 200 nm to 350 nm) are being energetically promoted at each research institution.

Since it is difficult to manufacture a nitride semiconductor as a bulk single crystal, a nitride semiconductor light emitting device has a nitride semiconductor layer formed on a dissimilar substrate such as a sapphire substrate or a silicon carbide substrate by a metalorganic vapor phase growth method (MOCVD). Crystal growth is being carried out.

Among the dissimilar substrates, the sapphire substrate is mainly used as a growth substrate because it is excellent in stability in a high temperature ammonia atmosphere in the crystal growth process by epitaxial growth. However, since the sapphire substrate is an insulating substrate and cannot be electrically conductive, it cannot be a nitride semiconductor light emitting device having a structure in which an n electrode and a p electrode are provided so as to sandwich the sapphire substrate.

Therefore, in the nitride semiconductor light emitting device manufactured by crystal-growing a nitride semiconductor layer on a sapphire substrate, for example, an n-type gallium nitride layer and a nitride semiconductor light emitting device structure are crystal-grown on a sapphire substrate by epitaxial growth. Later, the n-type gallium nitride layer is etched until the surface is exposed, and the n-electrode is formed on the exposed surface of the n-type gallium nitride layer, thereby providing the n-electrode and the p-electrode on the same surface side. Is common.

However, when the structure of the nitride semiconductor light emitting device is provided with the n electrode and the p electrode on the same surface side, the current tends to concentrate in the mesa portion close to the n electrode, so that the current is uniform in the light emitting layer. It is difficult to inject into the light emitting layer, and it is difficult to make the light emitting layer emit light evenly. Further, since it is necessary to form a wire bonding electrode on both the p electrode and the n electrode on the same surface side, either the p electrode or the n electrode in which the nitride semiconductor is crystal-grown on the conductive substrate. If an electrode for wire bonding is provided on one side, the effective light emitting area is narrower than that of a nitride semiconductor light emitting element having a structure that may be provided.

In order to solve such a problem, the nitride semiconductor is crystal-grown on the sapphire substrate, the sapphire semiconductor is peeled off to expose the nitride semiconductor, and n electrodes are formed on the exposed surface of the nitride semiconductor. , There is a method of manufacturing a nitride semiconductor light emitting device. When manufacturing a large-area nitride semiconductor light emitting device by this method, the following method is generally adopted.

For example, in Patent Document 1, in order to prevent cracking of the nitride semiconductor due to N ₂ gas generated by decomposition of the GaN buffer layer due to laser lift-off (LLO), a separation groove is formed in the GaN buffer layer in advance before irradiation with laser light. The method of forming the above is disclosed. According to this method, even N ₂ gas was decomposed GaN buffer layer by laser light irradiation occurs, it is possible to exhaust the N2 gas from the separation trench, a nitride semiconductor of a crack due to the N ₂ gas It is said that this can be prevented (paragraphs [0008] and [0009] of Patent Document 1 and the like).

Further, for example, in Patent Document 2, after forming one or more GaN layers on a sapphire substrate, the GaN layers are selectively removed by laser scribing or reactive ion etching to form grooves, and then the GaN layer is formed. A method of bonding a conductive substrate to a sapphire substrate and removing the sapphire substrate by LLO is disclosed (Patent Document 2, paragraph [0040], etc.).

Further, for example, Patent Document 3 discloses a method in which a gas release groove is formed in a holding substrate, a GaN crystal layer is grown on the surface of the holding substrate in which the gas release groove is formed, and the holding substrate is peeled off by LLO. (Paragraphs [0010], [0011], [0044], [0045], etc. of Patent Document 3).

JP-A-2007-134415 Special Table 2007-534164 Japanese Unexamined Patent Publication No. 2011-195377

However, when the method described in Patent Documents 1 to 3 is applied to the manufacture of a nitride semiconductor light emitting device, a laser is used to exhaust the gas generated by the decomposition of the GaN layer due to the irradiation of light in the LLO. It is necessary to form a groove at every shot interval of light. Therefore, the manufacturing yield of the nitride semiconductor light emitting device is lowered, and the size of the nitride semiconductor light emitting device is limited by the size per shot of the laser beam and the groove spacing, so that the area of the nitride semiconductor light emitting device is increased. There was a problem that the degree of freedom of was limited.

In view of the above circumstances, an object of the present invention is to provide a nitride semiconductor light emitting device and a method for manufacturing a nitride semiconductor light emitting device capable of manufacturing a large area nitride semiconductor light emitting device with a high yield.

According to the first aspect of the present invention, a nitride semiconductor light emitting device including a multilayer nitride semiconductor layer including a first conductive type nitride semiconductor layer, a light emitting layer, and a second conductive type nitride semiconductor layer in this order. Nitride semiconductor Nitride semiconductor having a grid-like structure including a convex region having a convex portion and a non-convex region surrounded by the convex region on the surface of the nitride semiconductor light emitting device. A light emitting element can be provided. Since the warp force of the multilayer nitride semiconductor layer can be suppressed by such a grid-like structure, it is possible to suppress a failure of adhesion failure due to repeated operation of the nitride semiconductor light emitting device, and thus the nitride semiconductor. The reliability of the light emitting element can be improved.

According to the second aspect of the present invention, a step of forming an Al (aluminum) -containing nitride semiconductor layer on the first surface of the growth substrate and a second method on the Al-containing nitride semiconductor layer. A step of forming a multilayer nitride semiconductor layer in which one conductive nitride semiconductor layer, a light emitting layer, and a second conductive nitride semiconductor layer are arranged in this order, and a surface of a substrate supporting the multilayer nitride semiconductor layer. After the step of joining on the top and the step of joining on the surface of the support substrate, a step of thinning the growth substrate from the second surface side opposite to the first surface of the growth substrate, and a step of thinning the growth substrate for growth. A step of peeling off the growth substrate by irradiating light from the second surface side of the substrate and absorbing at least a part of the light into a layer made of a nitride semiconductor containing Al, and a step of peeling off the growth substrate. In the step of peeling off the growth substrate, which includes the step of etching after the above, at least Al and oxygen are contained on at least one surface of the Al-containing nitride semiconductor layer and the first conductive type nitride semiconductor layer. In the process of forming and etching a substance, the surface of the first conductive nitride semiconductor layer is surrounded by a convex region having a convex portion and a convex region using a substance containing at least Al and oxygen as a mask. It is possible to provide a method for manufacturing a nitride semiconductor light emitting element in which a grid-like structure including a non-convex region is formed. In this case, by irradiating the light while forming a substance containing at least Al and oxygen by a step-and-repeat method or the like, a groove is not formed at each shot interval of the laser beam as in the conventional case. However, the occurrence of cracks at the interface between the light irradiation region and the multilayer nitride semiconductor layer can be suppressed, and a large-area growth substrate can be peeled off. Then, in the etching process after the growth substrate is peeled off, since the substance containing at least Al and oxygen has a function as a mask against etching, the surface of the nitride semiconductor light emitting device has a convex shape. It is possible to form a square-shaped structure including a convex region having a portion and a non-convex region surrounded by the convex region. Since the warp force of the multilayer nitride semiconductor layer can be suppressed by such a grid-like structure, it is possible to suppress a failure of adhesion failure due to repeated operation of the nitride semiconductor light emitting device, and thus the nitride semiconductor. The reliability of the light emitting element can be improved.

According to the present invention, it is possible to provide a nitride semiconductor light emitting device and a method for manufacturing a nitride semiconductor light emitting device, which can manufacture a large area nitride semiconductor light emitting device with a high yield.

It is a schematic cross-sectional view of the nitride semiconductor light emitting device of an embodiment. It is a simulated enlarged plan view of an example of the surface of the n-type nitride semiconductor layer of the nitride semiconductor light emitting device of the embodiment. FIG. 5 is a schematic enlarged plan view of another example of the surface of the n-type nitride semiconductor layer of the nitride semiconductor light emitting device of the embodiment. FIG. 5 is a schematic enlarged plan view of still another example of the surface of the n-type nitride semiconductor layer of the nitride semiconductor light emitting device of the embodiment. It is a schematic enlarged perspective sectional view of an example of the convex portion of the convex region of the nitride semiconductor light emitting device of the embodiment. It is a typical enlarged perspective sectional view of another example of the convex portion of the convex region of the nitride semiconductor light emitting device of the embodiment. It is a schematic enlarged perspective sectional view of still another example of the convex portion of the convex region of the nitride semiconductor light emitting device of the embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the nitride semiconductor light emitting device of embodiment. (A) is a schematic plan view illustrating an example of a process of peeling a thinned growth substrate by irradiation with light, and (b) is an example in the width direction of the light irradiation region shown in (a). (C) is a schematic cross-sectional view of an example in the length direction of the light irradiation region shown in (a). It is a schematic plan view which illustrates an example of the light irradiation method to the 2nd surface of a growth substrate. It is a schematic plan view which illustrates an example of the arrangement of the light irradiation area when the shape of the irradiation area per one irradiation of light is square. It is a schematic plan view which illustrates another example of the arrangement of the light irradiation area when the shape of the irradiation area per one irradiation of light is square. It is a schematic plan view which illustrates an example of the arrangement of the light irradiation area when the shape of the irradiation area per one irradiation of light is hexagonal. It is a schematic cross-sectional view which illustrates an example of the process of irradiating the second surface of a growth substrate with a slight scratch mark. (A) is a schematic plan view illustrating another example of the method of irradiating the second surface of the growth substrate with light, and (b) is a schematic side view of (a). It is a schematic plan view which illustrates an example of the method of irradiating light by a step-and-repeat method. It is a schematic cross-sectional view which illustrates an example of the step of providing a protective film so as to cover the side wall of a growth substrate, a buffer layer and a multilayer nitride semiconductor layer. It is a schematic cross-sectional view which illustrates an example of the process of joining a multilayer nitride semiconductor layer to a support substrate when a protective film is not provided so as to cover the side walls of the growth substrate, the buffer layer and the multilayer nitride semiconductor layer. .. It is a schematic cross-sectional view which illustrates an example of the process of joining a multilayer nitride semiconductor layer to a support substrate when a protective film is provided so as to cover the side walls of the growth substrate, the buffer layer and the multilayer nitride semiconductor layer. Schematic cross-sectional view illustrating a part of a process of peeling a support substrate from a multilayer nitride semiconductor layer when a protective film is provided so as to cover the side walls of the growth substrate, the buffer layer and the multilayer nitride semiconductor layer. Is. Schematic cross-sectional view illustrating a part of a process of peeling a support substrate from a multilayer nitride semiconductor layer when a protective film is provided so as to cover the side walls of the growth substrate, the buffer layer and the multilayer nitride semiconductor layer. Is. (A) and (b) are diagrams illustrating the distribution of an example of the oxygen concentration of an oxygen-containing substance. It is a schematic cross-sectional view which illustrates a part of the manufacturing process of the manufacturing method of the chip of Experimental Example 1. It is a schematic cross-sectional view which illustrates other part of the manufacturing process of the manufacturing method of the chip of Experimental Example 1. It is a surface observation image by an optical microscope of the surface of a chip after peeling of a sapphire substrate in Experimental Example 1. It is a figure which shows the result of the composition analysis measured by SEM-EDX of the convex shape part which constitutes the convex shape region of the surface of the chip in Experimental Example 2. It is a figure which shows the result of the composition analysis measured by SEM-EDX of the central region of the light irradiation region after immersing the chip in hydrofluoric acid in Experimental Example 3. FIG. 5 is a schematic plan view illustrating an example of a state in which the nitride semiconductor is scraped on the surface of the chip in Experimental Example 4. 6 is a schematic plan view illustrating an example of a square-shaped structure including a convex region and a non-convex region on the surface of the chip after etching in Experimental Example 6. 6 is a schematic enlarged cross-sectional view illustrating an example of the vicinity of the n-side electrode of the nitride semiconductor light emitting device of Experimental Example 6.

Hereinafter, embodiments that are an example of the present invention will be described. In addition, in the drawing of this specification, the same reference numeral shall represent the same part or the corresponding part.

<Construction of nitride semiconductor light emitting device>
FIG. 1 shows a schematic cross-sectional view of the nitride semiconductor light emitting device of the embodiment. The nitride semiconductor light emitting element of the embodiment shown in FIG. 1 includes a support substrate 9, a bonding material 8 provided on the support substrate 9, a p-side electrode 7 provided on the bonding material 8, and a p-side electrode. The p-type nitride semiconductor layer 5 provided on the p-type nitride semiconductor layer 5, the light emitting layer 4 provided on the p-type nitride semiconductor layer 5, the n-type nitride semiconductor layer 3 provided on the light emitting layer 4, and n. It is provided with an n-side electrode 19 provided on the type nitride semiconductor layer 3. Here, the multilayer nitride semiconductor layer 6 arranged on the p-side electrode 7 includes an n-type nitride semiconductor layer 3, a light emitting layer 4, and a p-type nitride semiconductor layer 5 in this order.

FIG. 2 shows a schematic enlarged plan view of an example of the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment. As shown in FIG. 2, the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment has a convex region 21 having a convex portion and a non-convex shape surrounded by the convex region 21. It has a grid-like structure including the region 22. That is, the convex region 21 is a region having a convex portion protruding above the non-convex region 22 from the surface of the n-type nitride semiconductor layer 3, and is arranged so as to surround the non-convex region 22. Has been done. The non-convex region 22 partitioned by the convex region 21 forms a grid-like structure on the surface of the n-type nitride semiconductor layer 3. In this case, the convex region 21 has a shape having a confluence point 23, which is one point where the convex regions 21 meet from four directions in a plan view.

FIG. 3 shows a schematic enlarged plan view of another example of the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment. In another example of the surface of the n-type nitride semiconductor layer 3 shown in FIG. 3, rectangular adjacent non-convex regions 22 are arranged so as to be displaced in the column direction when they are aligned in the row direction. , When they are aligned in the column direction, they are arranged so as to be offset in the row direction. In this case, the convex region 21 has a shape having a confluence point 23, which is one point at which the convex region 21 merges from three directions in a plan view.

FIG. 4 shows a schematic enlarged plan view of still another example of the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment. In another example of the surface of the n-type nitride semiconductor layer 3 shown in FIG. 4, the hexagonal adjacent non-convex regions 22 are arranged so as to be displaced in the column direction when they are aligned in the row direction. , When they are aligned in the column direction, they are arranged so as to be offset in the row direction. Also in this case, the convex region 21 has a shape having a confluence point 23, which is one point where the convex regions 21 meet from three directions in a plan view.

The convex region 21 preferably occupies 5% or more and 40% or less of the total area of the surface of the n-type nitride semiconductor layer 3 which is the surface of the nitride semiconductor light emitting device. When the convex region 21 occupies 5% or more and 40% or less of the total area of the surface of the n-type nitride semiconductor layer 3 which is the surface of the nitride semiconductor light emitting device, the convex region 21 and the non-convex shape are formed. The effect of being able to manufacture a large-area nitride semiconductor light-emitting device with good yield by forming a square-shaped structure including the region 22 can be more effectively exhibited, and the n-side electrode 19 is meshed. The disconnection of the n-side electrode 19 when formed in a shape can also be suppressed more effectively.

FIG. 5 shows a schematic enlarged perspective sectional view of an example of the convex portion of the convex region 21 of the nitride semiconductor light emitting device of the embodiment. The convex portion of the convex region 21 shown in FIG. 5 has an upper surface 31, a lower surface 32, and a slope 33 between the upper surface 31 and the lower surface 32, and a cross section of the convex portion of the convex region 21. The shape is trapezoidal. When the convex portion of the convex region 21 has the slope 33, the n-side electrode 19 is formed even when the n-side electrode 19 is formed so as to straddle the convex portion of the convex region 21. It is possible to suppress the occurrence of disconnection in.

Here, the width W of the lower surface 32 (the length in the direction orthogonal to the extension direction of the convex portion of the convex region 21) is preferably 5 μm or more and 100 μm or less. When the width W of the lower surface 32 is 5 μm or more and 100 μm or less, a large-area nitride semiconductor light emitting device can be manufactured more stably. Further, when the n-type nitride semiconductor layer 3 is exposed on the outermost surface of the nitride semiconductor light emitting device, the formation area of the n-side electrode 19 can be expanded, so that the contact resistance of the n-side electrode 19 is suppressed. can do.

Further, the height H of the convex portion of the convex region 21 is preferably 1000 nm or less. When the height H between the upper surface 31 and the lower surface 32 is 1000 nm or less, the n-side electrode 19 can be formed so as to straddle the convex portion of the convex region 21, and the n-side electrode 19 can be formed. It is possible to suppress adverse effects in process processes such as formation of (resist coating non-uniformity, defects in photolithography process, etc.).

FIG. 6 shows a schematic enlarged perspective sectional view of another example of the convex portion of the convex region 21 of the nitride semiconductor light emitting device of the embodiment. In the nitride semiconductor light emitting device of the embodiment, as shown in FIG. 6, the cross-sectional shape of the convex portion is a triangle, and the slope 33 is extended diagonally upward from both ends in the width direction of the lower surface 32 to form the lower surface 32. It may have a shape joined at the top.

The convex portion of the convex region 21 of the nitride semiconductor light emitting device of the embodiment may have a convex shape having some unevenness as shown in the schematic enlarged perspective sectional view of FIG. 7. .. Further, the convex portion of the convex region 21 may not be exactly linear, but may meander or extend so as to have a constant fluctuation in width. These cases are also acceptable as long as the effects of the nitride semiconductor light emitting device of the embodiment can be obtained.

It is preferable that the convex portion of the convex region 21 surrounds the non-convex region 22 in a completely continuous state, but as long as the effect of the nitride semiconductor light emitting device of the embodiment can be obtained, it is convex. It is also permissible that part of the shape portion is discontinuous.

<Manufacturing method of nitride semiconductor light emitting device>
Hereinafter, an example of a method for manufacturing a nitride semiconductor light emitting device according to the embodiment will be described with reference to the drawings.

(Formation of buffer layer)
First, as shown in the schematic cross-sectional view of FIG. 8, a buffer layer 2 which is a nitride semiconductor layer containing Al is formed on the first surface 1a of the growth substrate 1.

The growth substrate 1 is not particularly limited as long as it can form a buffer layer 2 containing Al on the first surface 1a of the growth substrate 1, but a sapphire (Al ₂ O ₃ ) substrate can be used. It is preferable to use it. Sapphire (Al ₂ O ₃ ) is suitable as a material for the growth substrate 1 because it has a high transmittance for light in a wide wavelength region ranging from 150 nm to 1000 nm, for example.

As the buffer layer 2, for example, a nitride semiconductor represented by the formula Al _x1 In _{y1 Gaz1} N (0 <x1 ≦ 1, 0 ≦ y1 ≦ 1, 0 ≦ z1 ≦ 1) can be used, and among them, AlN. Is more preferable to use. When AlN is used as the buffer layer 2, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) described later is effectively made to function as a mask in the etching step described later. Can be done.

The method for forming the buffer layer 2 is not particularly limited, and a crystal growth method such as a MOCVD (Metal Organic Chemical Vapor Deposition) method may be used, or a physical vapor deposition method such as a sputtering method may be used. .. The buffer layer 2 may be crystalline or amorphous.

(Formation of multilayer nitride semiconductor layer)
Next, as shown in the schematic cross-sectional view of FIG. 9, multilayer nitrided including the n-type nitride semiconductor layer 3, the light emitting layer 4, and the p-type nitride semiconductor layer 5 on the buffer layer 2 in this order. The physical semiconductor layer 6 is formed.

The n-type nitride semiconductor layer 3 includes, for example, a nitride semiconductor represented by the formula Al _x2 In _{y2 Gaz2} N (0 ≦ x2 ≦ 1, 0 ≦ y2 ≦ 1, 0 ≦ z2 ≦ 1, x2 + y2 + z2 ≠ 0). Those doped with n-type impurities can be used. As the n-type impurity, for example, silicon or the like can be used.

The light emitting layer 4 is, for example, a quantum well layer made of a nitride semiconductor represented by the formula Al _x3 In _{y3 Gaz3} N (0 ≦ x3 ≦ 1, 0 ≦ y3 ≦ 1, 0 ≦ z3 ≦ 1, x3 + y3 + z3 ≠ 0). A single quantum well light emitting layer (SQW) containing only one can be used. The light emitting layer 4 is, for example, a quantum made of a nitride semiconductor represented by the formula Al _x3 In _{y3 Gaz3} N (0 ≦ x3 ≦ 1, 0 ≦ y3 ≦ 1, 0 ≦ z3 ≦ 1, x3 + y3 + z3 ≠ 0). A band gap between a plurality of well layers and the quantum well layer is larger than that of the quantum well layer, for example, Al _x4 In _{y4 Gaz4} N (0 ≦ x4 ≦ 1, 0 ≦ y4 ≦ 1, 0 ≦ z4 ≦ 1). , X4 + y4 + z4 ≠ 0) It is also possible to use a multiple quantum well light emitting layer (MQW) including a quantum barrier layer made of a nitride semiconductor represented by the equation. The light emitting layer 4 may be doped with n-type impurities and / or p-type impurities. As the n-type impurity doped in the light emitting layer 4, for example, silicon or the like can be used, and as the p-type impurity, for example, magnesium or the like can be used.

The p-type nitride semiconductor layer 5 includes, for example, a nitride semiconductor represented by the formula Al _x5 In _{y5 Gaz5} N (0 ≦ x5 ≦ 1, 0 ≦ y5 ≦ 1, 0 ≦ z5 ≦ 1, x5 + y5 + z5 ≠ 0). Those doped with p-type impurities can be used. As the p-type impurity, for example, magnesium or the like can be used.

In particular, when the Al composition ratio is 40% or more (0.4 ≦ x5 ≦ 1), the current spread in the lateral direction is significantly reduced in the n-type nitride semiconductor layer 3 and the p-type nitride semiconductor layer 5. I have something to do. Therefore, in this case, it is preferable to introduce a structure capable of promoting the spread of the current in the lateral direction inside or the outermost surface of the p-type nitride semiconductor layer 5, for example. For example, the structure may have an insulator such as SiO ₂ between the p-type nitride semiconductor layer 5 directly below the n-side electrode 19 and the p-side electrode 7. When the electrons injected from the n-side electrode 19 and the holes injected from the p-side electrode 7 are coupled at the shortest distance and there is no lateral current spread, the light emission directly under the n-side electrode 19 is dominant. There is a possibility that the light emission will be absorbed by the n-side electrode 19. However, by introducing such a structure, it is possible to promote the spread of the current in the lateral direction, so that the amount of light absorbed by the n-side electrode 19 can be reduced.

As a method for forming the n-type nitride semiconductor layer 3, the light emitting layer 4, and the p-type nitride semiconductor layer 5, for example, a crystal growth method such as the MOCVD method can be used.

The total thickness T1 of the multilayer nitride semiconductor layer 6 and the buffer layer 2 is preferably 3 μm or more, and more preferably 4 μm or more. When the total thickness T1 of the multilayer nitride semiconductor layer 6 and the buffer layer 2 is 3 μm or more, particularly when it is 4 μm or more, the buffer is subjected to light irradiation in the step of peeling the growth substrate 1 described later. It is possible to suppress the adverse effect of the shock wave on the light emitting layer 4 which is considered to occur when the layer 2 is thermally decomposed and the growth substrate 1 and the buffer layer 2 in which all or a part thereof are decomposed are separated (multilayer nitride). If the total thickness T1 of the material semiconductor layer 6 and the buffer layer 2 is thin, the nitride semiconductor may be crushed).

When the total thickness T1 of the multilayer nitride semiconductor layer 6 and the buffer layer 2 is 3 μm or more, the distance T2 between the growth substrate 1 and the light emitting layer 4 maintains the relationship of T1> T2. However, it is more preferably 3 μm or more. In this case, in the step of peeling the growth substrate 1 described later, the distance T2 between the portion where the buffer layer 2 is thermally decomposed by irradiation with light and the light emitting layer 4 becomes large, and light is emitted to the buffer layer 2. The influence of the heat generated during irradiation on the light emitting layer 4 can also be suppressed.

The thickness T3 of the n-type nitride semiconductor layer 3 is preferably 1 μm or more, and more preferably 2 μm or more. When the thickness T3 of the n-type nitride semiconductor layer 3 is 1 μm or more, particularly when it is 2 μm or more, the controllability of etching of the n-type nitride semiconductor layer 3 can be improved in the etching step described later. it can.

Further, the total thickness T1 of the multilayer nitride semiconductor layer 6 and the buffer layer 2 is preferably 10 μm or less. When the total thickness T1 of the multilayer nitride semiconductor layer 6 and the buffer layer 2 is 10 μm or less, it is possible to suppress an increase in the formation time and raw material cost of the buffer layer 2 and the multilayer nitride semiconductor layer 6.

(P-type process)
After that, the wafer after the formation of the multilayer nitride semiconductor layer 6 (in the embodiment, a laminate of the growth substrate 1, the buffer layer 2 and the multilayer nitride semiconductor layer 6) can be heat-treated. As a result, a p-type dopant such as Mg in the p-type nitride semiconductor layer 5 can be activated, so that the p-type nitride semiconductor layer 5 can exhibit a function as a p-type semiconductor.

The heat treatment conditions for the wafer after the formation of the multilayer nitride semiconductor layer 6 are not particularly limited, but for example, the conditions for heat-treating the wafer after the formation of the multilayer nitride semiconductor layer 6 in an oxygen atmosphere at 800 ° C. for about 10 minutes are satisfied. Can be mentioned.

(Chip)
Next, the growth substrate 1 after the formation of the multilayer nitride semiconductor layer 6 is divided into chips. The size and shape of the surface of one chip are not particularly limited, and examples thereof include a square having a side of 4 mm, a square having a side of 5 mm, a square having a side of 10 mm, and a rectangle. By increasing the area of the surface of the chip, the output of the nitride semiconductor light emitting device can be increased.

It should be noted that the chipping does not have to be performed at this stage, and the processing may proceed in the state of the wafer and the chipping may be performed at the final stage. In this case, until the final stage, it is sufficient to handle one wafer having a plurality of chips, and the throughput tends to be increased.

(Joining of multilayer nitride semiconductor layers)
Next, as shown in the schematic cross-sectional view of FIG. 10, the multilayer nitride semiconductor layer 6 is bonded onto the surface of the support substrate 9.

The method of joining the multilayer nitride semiconductor layer 6 on the surface of the support substrate 9 is not particularly limited. For example, the p-side electrode 7 laminated on the multilayer nitride semiconductor layer 6 and the multilayer nitride semiconductor layer 6 are installed on the surface of the support substrate 9. This can be done by joining the bonding material 8.

As the p-side electrode 7, a material having a low contact resistance with the p-type nitride semiconductor layer 5 can be preferably used. For example, a laminate of a Pd layer and an Au layer, a laminate of a Ni layer and an Au layer, and the like. An Al layer, a Ni layer, a Pt layer, or the like can be used. Among them, in the structure for extracting light from the n side, it is preferable to use the Al layer as the p-side electrode 7 from the viewpoint of reflecting the light emitted from the light-emitting layer 4 at the p-side electrode 7 with a higher reflectance. The layer and the Pt layer also have a relatively high reflectance with respect to the light emitted from the light emitting layer 4, and are preferable from the viewpoint of reducing the contact resistance with the p-type nitride semiconductor layer 5.

The method for forming the p-side electrode 7 is not particularly limited, but for example, an EB (Electron Beam) vapor deposition method or the like can be used.

The surface of the p-type nitride semiconductor layer 5 on which the p-side electrode 7 is formed may be acid-treated prior to the formation of the p-side electrode 7, and the acid treatment may be, for example, the p-type nitride semiconductor layer. This can be done by immersing the surface of No. 5 in hydrofluoric acid for 3 minutes, washing with water, and drying.

After the formation of the p-side electrode 7, the p-side electrode 7 may be heat-treated, and the heat treatment of the p-side electrode 7 is performed at about 800 ° C. in, for example, an oxygen atmosphere, a nitrogen atmosphere, or a dry air atmosphere. This can be done by heating the p-side electrode 7 for 10 minutes.

As the support substrate 9, for example, a semiconductor substrate made of a semiconductor such as Si, SiC or GaAs, a single metal substrate, or a metal substrate made of a composite of two or more kinds of metals can be used. As the metal substrate, for example, one or more metals selected from highly conductive metals such as Ag, Cu, Au and Pt, and one selected from high hardness metals such as W, Mo, Cr and Ni. Those made of the above metals can be used. Further, as the metal substrate, for example, a composite such as Cu-W or Cu-Mo can be used. Further, as the support substrate 9, ceramic or the like having excellent heat dissipation can be used.

As the bonding material 8, Au, Sn, Pd, In, Ti, Ni, W, Mo, Au-Sn, Sn-Pd, In-Pd, Ti-Pt-Au, Ti-Pt-Sn, or the like can be used. preferable. When these materials are used as the bonding material 8, they can be bonded to the p-side electrode 7 by a eutectic reaction. The eutectic cambium formed by the eutectic reaction is a layer that diffuses with each other to form an eutectic when joined to the p-side electrode 7.

As the combination of the eutectic cambium, for example, a combination of Au-Sn, Sn-Pd, or In-Pd can be used. Further, when the bonding material 8 is bonded to the p-side electrode 7 by a eutectic reaction, the bonding temperature can be in the range of, for example, about 150 ° C. to 400 ° C.

As the bonding material 8, a thermosetting conductive adhesive containing Ag or the like can also be used. Examples of the joining condition include a condition in which a pressurization of about several hundred N to several kN is performed, the temperature is heated to about 150 ° C. to 400 ° C., and the temperature is maintained in a vacuum or a nitrogen atmosphere for about 15 minutes. When joining in a non-pressurized state, for example, a condition of heating at about 200 ° C. in the air and holding for about 60 minutes can be mentioned. Select the conditions according to the characteristics of the material.

In the above, the buffer layer 2, the n-type nitride semiconductor layer 3, the light emitting layer 4, and the p-type nitride semiconductor layer 5 are formed from the growth substrate 1 side, and the p-side electrode is formed on the p-type nitride semiconductor layer 5. Although an example of forming the 7 and joining the bonding material 8 installed on the surface of the support substrate 9 is shown, it is also possible to make the configuration upside down. Specifically, the buffer layer 2, the p-type nitride semiconductor layer 5, the light emitting layer 4, and the n-type nitride semiconductor layer 3 are laminated in this order from the growth substrate 1, and n on the n-type nitride semiconductor layer 3. It is also possible to form a side electrode and join the bonding material 8 installed on the surface of the support substrate 9.

(Thinning of growth substrate)
Next, as shown in the schematic cross-sectional view of FIG. 11, the growth substrate 1 is thinned from the second surface 1b side of the growth substrate 1. The method for thinning the growth substrate 1 is not particularly limited, but it can be performed, for example, by grinding and / or polishing the second surface 1b of the growth substrate 1.

Due to the thinning of the growth substrate 1, the thickness t1 of the growth substrate 1 is preferably 100 μm or less, more preferably 80 μm or less, and particularly preferably 60 μm or less.

When the thickness t1 of the growth substrate 1 is 100 μm or less, more preferably 80 μm or less, particularly 60 μm or less, a buffer is provided by irradiation with light in the step of peeling the growth substrate 1 described later. A substance containing at least Al and oxygen (for example, Al, oxygen, and nitrogen) between the growth substrate 1 and the buffer layer 2 or the multilayer nitride semiconductor layer 6 in which the layer 2 is partially decomposed by thermal decomposition. A substance containing and) tends to be formed. Further, there is a tendency that the growth substrate 1 can be peeled off more smoothly.

Due to the thinning of the growth substrate 1, the thickness t1 of the growth substrate 1 is preferably 20 μm or more. When the thickness t1 of the growth substrate 1 is 20 μm or more due to the thinning of the growth substrate 1, the growth substrate 1 may become too thin, which may adversely affect the multilayer nitride semiconductor layer 6. Will be low.

After the growth substrate 1 is thinned, it is preferable to mirror-polish the second surface 1b of the growth substrate 1. By making the second surface 1b of the growth substrate 1 a mirror surface, the light irradiated in the step of peeling the growth substrate 1 described later is not scattered on the second surface 1b of the growth substrate 1, so that the buffer is used. Since the layer 2 can be uniformly irradiated with light, the growth substrate 1 can be uniformly peeled off.

As used herein, the term "mirror surface" means a mirror surface that can be carried out by a conventionally known mirror surface polishing process.

Hereinafter, a preferable example of a method for reducing the thickness of the growth substrate 1 will be described. First, the thickness of the growth substrate 1 is set to, for example, about 150 μm to 200 μm by grinding the second surface 1b of the growth substrate 1. Next, in order to remove scratches caused by grinding and improve the mirror surface property of the second surface 1b of the growth substrate 1 after grinding, it is thinned by polishing until it has a thickness of, for example, about 40 μm to 100 μm. Then, the thickness of the growth substrate 1 is reduced to, for example, about 40 μm to 100 μm by CMP (chemical mechanical polishing). Since scratch scratches on the second surface 1b of the growth substrate 1 can be removed by CMP, the second surface 1b of the growth substrate 1 was irradiated with light in the step of peeling the growth substrate 1 described later. Even in this case, the light is not scattered and the buffer layer 2 can be uniformly irradiated. When there are many scratches, the irradiated light is scattered, so that a region where the growth substrate 1 does not peel off is partially generated, and the peeling yield of the growth substrate 1 may decrease. Therefore, scattering of the irradiated light can be suppressed by removing scratches on the second surface 1b of the growth substrate 1 by CMP. Further, the CMP can prevent the scratches formed on the growth substrate 1 from being transferred to the buffer layer 2 or the multilayer nitride semiconductor layer 6 in which a part thereof is thermally decomposed.

Further, even when the uniformity of the light applied to the buffer layer 2 is lowered, if the growth substrate 1 can be peeled off, the second surface 1b of the growth substrate 1 may be used as a rough surface. The fact that the second surface 1b of the growth substrate 1 is a rough surface is rougher than the surface state after grinding and / or polishing the second surface 1b of the growth substrate 1 without performing CMP. Means face.

(Peeling of growth substrate)
Next, as shown in the schematic cross-sectional view of FIG. 12, by irradiating the light 10 from the second surface 1b side of the growth substrate 1, at least a part of the light 10 is absorbed by the buffer layer 2 and grown. Peel off the substrate 1.

In the peeling of the growth substrate 1, at least a part of the light 10 is absorbed by the buffer layer 2 made of a nitride semiconductor containing Al, and at least a part of the buffer layer 2 is thermally decomposed to generate nitrogen gas. A shock wave is generated by this nitrogen gas, and the thinned growth substrate 1 is deformed by the force of the shock wave, so that between the growth substrate 1 and the multilayer nitride semiconductor layer 6, for example, the schematic diagram of FIG. It is expected that the space 11 as shown in the cross-sectional view will be formed. By forming the space 11, the growth substrate 1 can be peeled off.

The space 11 is formed in the central region of the region irradiated with the light 10, while the growth substrate 1 and the buffer layer 2 are formed in the peripheral region of the region irradiated with the light 10 as shown in FIG. It is considered that Al and nitrogen generated by the buffer layer 2 absorbing the light 10 and thermally decomposing the light 10 are present at a high density.

Further, when a substrate containing oxygen such as a sapphire substrate is used as the growth substrate 1, oxygen generated by the thermal decomposition of the growth substrate 1 and Al and nitrogen generated by the thermal decomposition of the buffer layer 2 are used. It is considered that a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is formed in the region by reacting with such a substance. The oxygen contained in at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is not limited to that obtained by thermal decomposition of the growth substrate 1 made of a substrate containing oxygen. , For example, oxygen in the atmosphere.

Here, since the distance between the growth substrate 1 and the buffer layer 2 gradually narrows from the central region to the peripheral region of the region irradiated with the light 10, the central region of the region irradiated with the light 10 is used. An oxygen concentration gradient is formed in which the oxygen concentration of a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) gradually increases toward the peripheral region. The substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) is, for example, when only a part of the buffer layer 2 in the thickness direction is thermally decomposed by irradiation with light 10. Is formed on the surface of the buffer layer 2, and can be formed on the surface of the n-type nitride semiconductor layer 3 when all of the thickness direction of the buffer layer 2 is thermally decomposed by irradiation with light 10.

In the embodiment, a substance (for example, Al, oxygen, and nitrogen) containing at least Al and oxygen on at least one surface of the buffer layer 2 and the n-type nitride semiconductor layer 3 each time the light 10 is irradiated. The growth substrate 1 can be peeled off while forming a substance containing and. According to this method, for example, even if the surface shape of the nitride semiconductor light emitting device is a large area such as a square or a rectangle having a side of 500 μm or more, or a circular or elliptical shape having an equivalent large area. The growth substrate 1 can be smoothly peeled off.

FIG. 14 (a) shows a schematic plan view illustrating an example of a step of peeling the thinned growth substrate 1 of the embodiment by irradiation with light 10, and FIG. 14 (b) shows FIG. 14 (a). A schematic cross-sectional view of an example in the width direction of the irradiation region 12 of the light 10 shown in FIG. 14 (c) is shown, and an example in the length direction of the irradiation region 12 of the light 10 shown in FIG. A schematic cross-sectional view is shown.

As shown in FIGS. 14 (a) to 14 (c), in the central region 42 of the irradiation region 12 of the light 10, the distance between the growth substrate 1 and the buffer layer 2 is wide, but the peripheral edge In the region 41, the distance between the growth substrate 1 and the buffer layer 2 is narrowed, as is clear from the portions surrounded by the ellipses in FIGS. 14 (b) and 14 (c). Therefore, in the peripheral region 41 of the irradiation region 12 of the light 10, it is considered that pools of Al, nitrogen, etc. generated by the thermal decomposition of the buffer layer 2 due to the irradiation of the light 10 are generated.

Further, the buffer layer 2 instantly reaches a high temperature by irradiation with light 10, and at this time, thermal decomposition of the growth substrate 1 is also conceivable. Therefore, when the growth substrate 1 is a substrate containing oxygen such as a sapphire substrate, in the peripheral region 41 of the irradiation region 12 of the light 10, in addition to the influence of oxygen in the atmosphere, the growth substrate 1 Under the influence of oxygen generated by thermal decomposition, the oxygen concentration of at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) becomes high. As a result, an oxygen concentration gradient in which the oxygen concentration of a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen, and nitrogen) increases from the central region 42 to the peripheral region 41 of the irradiation region 12 of the light 10. Is formed, so that the convex region 21 having the convex portion can be easily formed by the etching step described later.

At this time, the substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) contains, for example, an oxygen concentration of 60 atomic% or less. For example, under certain conditions, an energy dispersive X attached to a scanning electron microscope (SEM) can be used to obtain a substance containing Al, oxygen, and nitrogen generated by irradiating an AlN layer on a sapphire substrate with an excimer laser beam having a wavelength of 193 nm. As an example of the measured value when measured by a ray analyzer (SEM-EDX), the oxygen concentration of the substance containing Al, oxygen and nitrogen is 20 atomic% in the central region 42 of the irradiation region 12 of the light 10. From the central region 42 to the peripheral region 41 of the irradiation region 12 of the light 10, the oxygen concentration of the substance containing Al, oxygen and nitrogen gradually increases, and the substance containing Al, oxygen and nitrogen in the peripheral region 41 There is an example in which the oxygen concentration of is 40 atomic%.

The oxygen concentration of a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) in the peripheral region 41 of the irradiation region 12 of the light 10 is set to, for example, an acid etching such as hydrofluoric acid. It can be reduced to 5 atomic% or less by etching by immersing it for about 10 minutes. The substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) in the central region 42 of the irradiation region 12 of the light 10 is, for example, in an acid-based etching such as hydrofluoric acid for about 10 minutes. It can be removed by dipping etching. Regarding the substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) in the peripheral region 41 of the irradiation region 12 of the light 10, for example, an acid-based etchant such as phosphoric acid or water. It can be removed by treatment with an alkaline etchant such as potassium oxide. It can be completely removed by a combination of these solution treatments.

In the conventional methods described in Patent Documents 1 to 3, the substance generated by the thermal decomposition caused by the irradiation of light is smoothly released to the outside through the groove. Therefore, in the conventional methods described in Patent Documents 1 to 3, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen, and nitrogen) as described above is not formed. Further, since the buffer layer to be thermally decomposed is GaN, Al is not generated by the thermal decomposition, so that it is not formed.

(Irradiation of light)
FIG. 15 shows a schematic plan view illustrating an example of a method of irradiating the second surface 1b of the growth substrate 1 with light 10. As shown in FIG. 15, the light 10 is irradiated, for example, on the second surface 1b of the growth substrate 1 while moving the irradiation region 12 of the light 10 in the direction of the arrow 13.

As shown in FIG. 15, it is preferable to irradiate the light 10 so that the irradiation regions 12 of the light 10 do not overlap each other and the irradiation regions 12 of the light 10 are adjacent to each other. When the light 10 is irradiated in this way, the following phenomenon occurs.

First, the irradiation of the first light 10 opens the upper side and the right side of the four rectangular sides of the irradiation area 12 (irradiation area 12 in the upper right of FIG. 15) of the first light 10. The nitrogen gas generated by the thermal decomposition of the buffer layer 2 by the irradiation of the first light 10 is discharged to the outside from the upper side and the right side of the irradiation region 12. In this way, the smooth release is due to the fact that the growth substrate is thinned so that the space is smoothly formed by irradiation.

Next, in the irradiation region 12 of the second light 10, the second light 10 is from the upper side where the space is already formed by the irradiation region 12 of the first light 10 and the right side which is originally open. Nitrogen gas generated by thermal decomposition of the buffer layer 2 by irradiation is released to the outside from the upper side and the right side of the irradiation region 12.

As described above, in the irradiation of the light 10 in the rightmost column, the nitrogen gas generated by the thermal decomposition of the buffer layer 2 is sequentially applied to the upper side and the right side of the irradiation region 12 for each irradiation region 12 of the light 10. Is released to the outside.

Further, the irradiation region 12 of the light 10 in the second column from the right has already been opened on the right side by the irradiation of the light 10 in the rightmost column, and the irradiation beyond the light 10 in the second column from the right. The upper side is also open. Therefore, even in the second row from the right, the nitrogen gas is discharged to the outside from the upper side and the right side of the irradiation region 12.

By sequentially irradiating the light 10 in this way, nitrogen gas is emitted to the outside from the upper side and the right side of the irradiation region 12 of the light 10, and at least the lower side and the left side of the irradiation region 12 of the light 10 are emitted. A substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is formed.

Here, the shape of the irradiation region 12 per irradiation of the light 10 is preferably a rectangle having at least one side length of 100 μm or more, and more preferably a square having a side length W1 of 100 μm or more. preferable. When the shape of the irradiation region 12 per one irradiation of the light 10 is a rectangle having all side lengths of 100 μm or more, especially when the side length W1 is a square having 100 μm or more, a large area Since the number of times of irradiation of the light 10 for peeling the growth substrate 1 can be reduced, the manufacturing efficiency of the nitride semiconductor light emitting device can be improved.

Further, the shape of the irradiation region 12 per irradiation of the light 10 is preferably a rectangle having at least one side length of 2000 μm or less, and preferably a square having a side length W1 of 2000 μm or less. When the shape of the irradiation region 12 per irradiation of the light 10 is a square having a side length W1 of 2000 μm or less, the energy density of the light 10 required for peeling the growth substrate 1 can be easily obtained. Can be done.

Further, when the shape of the irradiation region 12 per one irradiation of the light 10 is a hexagon, the length of one side of the hexagon is preferably 50 μm or more, and more preferably 100 μm or more. When the shape of the irradiation region 12 per irradiation of the light 10 is a hexagon having a side length of 50 μm or more, particularly when the side length is 100 μm or more, a large area Since the number of times of irradiation of the light 10 for peeling the growth substrate 1 can be reduced, the manufacturing efficiency of the nitride semiconductor light emitting device can be improved.

Further, when the shape of the irradiation region 12 per one irradiation of the light 10 is a hexagon, the length of one side of the hexagon is preferably 2000 μm or less. When the shape of the irradiation region 12 per one irradiation of the light 10 is a hexagon having a side length W1 of 2000 μm or less, the energy density of the light 10 required for peeling the growth substrate 1 can be easily obtained. be able to.

Specifically, as a preferable shape of the irradiation region 12 per irradiation of the light 10, for example, a square having a side length W1 of about 500 μm or a hexagon having a side length of about 300 μm can be mentioned. It can be done, but it is not particularly limited to this.

As shown in FIG. 15, the light 10 may be irradiated so as to completely fill the entire surface of the second surface 1b of the growth substrate 1. Further, at least a part of the irradiation region 12 of the light 10 may be irradiated while overlapping. When the shape of the irradiation region 12 per irradiation of the light 10 is, for example, rectangular or square, the shape of the irradiation region 12 per irradiation of the light 10 can be effectively used.

Further, the shape of the irradiation region 12 per one irradiation of the light 10 may be, for example, a circle. In this case, in order to irradiate the light 10 so as to completely fill the entire surface of the second surface 1b of the growth substrate 1, it is necessary to overlap at least a part of the irradiation region 12 of the light 10.

It is also possible to irradiate the irradiation regions 12 of the light 10 at regular intervals without overlapping them. In this case, the distance between the irradiation regions 12 of the light 10 is preferably 100 μm or less, and more preferably 10 μm or less.

In addition, in this specification, "rectangle", "square" and "hexagon" do not strictly mean "rectangle", "square" and "hexagon", for example, a metal mask or It may be changed to the extent that it can be shaped by a photomask or the like. For example, "rectangle" and "square" include those in which at least one of the four corners is not exactly a right angle but is rounded due to light interference or the like. Further, the "square" includes those in which even if the photomask or the metal mask is square, the lengths of one side are not completely the same due to the adjustment of the optical system.

FIG. 16 shows a schematic plan view illustrating an example of the arrangement of the irradiation region 12 of the light 10 when the shape of the irradiation region 12 per irradiation of the light 10 is square. In the example shown in FIG. 16, the square-shaped irradiation region 12 of the light 10 is aligned in both the row direction and the column direction so as to completely fill the entire surface of the second surface 1b of the growth substrate 1. , Light 10 is irradiated. In this case, a convex portion having a convex portion is formed on the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment in a shape as shown in FIG. 2 by undergoing an etching step described later. It is possible to form a grid-like structure including a shape region 21 and a non-convex region 22 surrounded by the convex region 21.

In the example shown in FIG. 16, there is a portion (four-point concentrated portion 51) on the second surface 1b of the growth substrate 1 that is irradiated with the light 10 four times. From the viewpoint of avoiding a decrease in yield due to an excessive irradiation energy of the light 10 or an adverse effect due to fluctuations in the irradiation energy of the light 10, the number of overlaps is increased in the place where the irradiation of the light 10 overlaps. Less is preferable.

FIG. 17 shows a schematic plan view illustrating another example of the arrangement of the irradiation region 12 of the light 10 when the shape of the irradiation region 12 per irradiation of the light 10 is square. In the example shown in FIG. 17, when the irradiation regions 12 of the light 10 are aligned in the row direction, they are displaced in the column direction, and when they are aligned in the column direction, they are displaced in the row direction. The light 10 is irradiated so as to completely fill the entire surface of the second surface 1b without any gaps. In this case, by going through the etching step described later, the shape as shown in FIG. 3 is convex having a convex portion on the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment. It is possible to form a grid-like structure including a shape region 21 and a non-convex region 22 surrounded by the convex region 21.

In the example shown in FIG. 17, a portion (three-point concentrated portion 52) that receives the irradiation of light 10 three times can be present on the second surface 1b of the growth substrate 1. In the example shown in FIG. 17, since the number of overlapping irradiations of the light 10 at the three-point concentrated points 52 is the maximum, the number of overlapping times of the irradiation of the light 10 is increased as compared with the four-point concentrated points 51 in the example shown in FIG. Since the amount can be reduced and the adverse effect caused by the irradiation damage of the light 10 can be suppressed, a large-area nitride semiconductor light emitting device can be manufactured with a high yield.

FIG. 18 shows a schematic plan view illustrating an example of the arrangement of the irradiation region 12 of the light 10 when the shape of the irradiation region 12 per irradiation of the light 10 is hexagonal. In the example shown in FIG. 18, when the irradiation regions 12 of the light 10 are aligned in the row direction, they are displaced in the column direction, and when they are aligned in the column direction, they are displaced in the row direction. The light 10 is irradiated so as to completely fill the entire surface of the second surface 1b without any gaps. In this case, by going through the etching step described later, the shape as shown in FIG. 4 is convex having a convex portion on the surface of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device of the embodiment. It is possible to form a grid-like structure including a shape region 21 and a non-convex region 22 surrounded by the convex region 21.

Also in the example shown in FIG. 18, the second surface 1b of the growth substrate 1 can have a portion 52 (three-point concentrated portion) that is irradiated with the light 10 three times, and the light 10 at the three-point concentrated portion 52 can be present. Since the number of overlapping irradiations of the light 10 is maximized, the number of overlapping times of the irradiation of the light 10 can be reduced as compared with the four-point concentrated portion 51 in the example shown in FIG. 16, and the adverse effect caused by the irradiation damage of the light 10 can be reduced. Since it can be suppressed, a large-area nitride semiconductor light emitting device can be manufactured with good yield. Further, since the arrangement shape of the irradiation region 12 is a control, the influence of the irradiation of light 10 on the nitride semiconductor can be uniformly suppressed, so that a large-area nitride semiconductor light emitting device can be manufactured with a high yield. it can.

The wavelength of the light 10 irradiated on the second surface 1b of the growth substrate 1 is preferably 200 nm or less. When the wavelength of the light 10 is 200 nm or less, the light 10 decomposes oxygen in the atmosphere. Therefore, a substance containing at least Al and oxygen (for example, Al and oxygen) generated during the thermal decomposition of the buffer layer 2 A substance containing nitrogen) can take in more oxygen. As a result, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) can be formed in a desired shape. Therefore, the convex region 21 is formed on the surface of the nitride semiconductor light emitting device. And the non-convex shape region 22 can be formed into a desired shape. Further, when the wavelength of the light 10 is 200 nm or less, when the growth substrate 1 is a sapphire substrate, the light 10 preferably transmits the growth substrate 1 and a buffer made of a nitride semiconductor containing Al. The layer 2 tends to efficiently absorb the light 10 and thermally decompose it. In particular, from the viewpoint of allowing the buffer layer 2 to absorb the light 10 more efficiently and thermally decomposing it, the buffer layer 2 is preferably AlN.

As an example of the irradiation condition of the light 10, an ArF excimer laser device is used as the light source of the light 10, and the irradiation energy density of the light 10 (wavelength 193 nm) is about 500 to 8000 mJ / cm ² . Irradiation energy may have various possibilities depending on the device such as the irradiation shape of the light 10 and the optical system. For example, every time the irradiation shape or the optical system is changed, a light irradiation experiment is performed to grow with the buffer layer 2. It can be determined by confirming the peeling from the substrate 1.

Even when the second surface 1b of the growth substrate 1 is mirror-polished by CMP or the like, slight scratches may remain on the second surface 1b of the growth substrate 1. For example, as shown in the schematic cross-sectional view of FIG. 19, when the scratch scratch 14 is formed on the second surface 1b of the growth substrate 1, the growth substrate 1 is warped after being irradiated with light 10. The space 11 is likely to be formed between the growth substrate 1 and the buffer layer 2 or the multilayer nitride semiconductor layer 6 that has been thermally decomposed by irradiation with light 10. The depth of the scratch scratch 14 is preferably 50 nm or less, and the width of the opening of the scratch scratch 14 is preferably 20 μm or less. In this case, the space 11 can be easily formed. Further, it is more preferable that the depth of the scratch scratch 14 is 30 nm or less, and the width of the opening of the scratch scratch 14 is 10 μm or less. In this case, since the adverse effect of the irradiation of the light 10 is small and the growth substrate 1 is warped, the space 11 can be formed more preferably.

On the other hand, when the second surface 1b of the growth substrate 1 is ground and / or polished without performing CMP to make the second surface 1b of the growth substrate 1 a rough surface, the growth substrate 1 Since the number of scratches 14 formed on the second surface 1b of the above is too large, the light 10 irradiated on the second surface 1b of the growth substrate 1 is scattered, and as a result, uniform peeling of the growth substrate 1 is difficult. May be.

FIG. 20 (a) shows a schematic plan view illustrating another example of the method of irradiating the second surface 1b of the growth substrate 1 with light 10, and FIG. 20 (b) shows the schematic of FIG. 20 (a). Side view is shown. Here, as shown in FIGS. 20A and 20B, the irradiation of the light 10 moves in the direction of the arrow 13 so that the irradiation region 12 of the light 10 protrudes from the peripheral edge of the multilayer nitride semiconductor layer 6. It is preferable to carry out while letting. Further, it is more preferable that the protrusion width W2 from the peripheral edge of the multilayer nitride semiconductor layer 6 is 60 μm or more when the length W1 of one side of the irradiation region 12 of the light 10 is 300 μm. Further, it is more preferable that the length of one side of the irradiation region 12 of the light 10 is W1 and the protrusion width W2 satisfies the relationship of ((W1) / 5) ≦ W2 ≦ ((W1) / 2). When W1 and W2 satisfy the above relationship, the growth substrate 1 is efficiently peeled off while sufficiently securing the overlapping region between the irradiation region 12 of the light 10 and the multilayer nitride semiconductor layer 6. Can be done. Further, at the end of the overlapping region between the irradiation region 12 of the light 10 and the multilayer nitride semiconductor layer 6, one ends of the buffer layer 2 and the multilayer nitride semiconductor layer 6 are open, so that nitrogen generated by thermal decomposition is generated. The gas can be effectively released to the outside. In the region where one end of the buffer layer 2 and the multilayer nitride semiconductor layer 6 is open, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is not formed. Opening one end of the buffer layer 2 and the multilayer nitride semiconductor layer 6 is effective from the viewpoint of peeling off the growth substrate 1.

In particular, as shown in the schematic plan view of FIG. 21, it is preferable to irradiate the light 10 (step-and-repeat method) while moving the irradiation region 12 of the light 10 in the directions of the arrows 13a, 13b, 13c, 13d. The relationship between the length W1 of one side of the irradiation region 12 and the protrusion width W2 from the peripheral edge of the multilayer nitride semiconductor layer 6 of the irradiation region 12 is ((W1) / 5) ≤ W2 ≤ ((W1) / 2). It is more preferable to irradiate the light 10 by the step-and-repeat method so as to satisfy the conditions. Also in this case, at the end of the overlapping region between the irradiation region 12 of the light 10 and the multilayer nitride semiconductor layer 6, one ends of the buffer layer 2 and the multilayer nitride semiconductor layer 6 are open, so that they are thermally decomposed. The generated nitrogen gas can be effectively released to the outside.

(Installation of protective film)
Further, as shown in the schematic cross-sectional view of FIG. 22, it is preferable to provide at least a protective film 15 such as SiO ₂ so as to cover the side walls of the growth substrate 1, the buffer layer 2, and the multilayer nitride semiconductor layer 6. As shown in the schematic cross-sectional view of FIG. 23, when the bonding material 8 adheres to the side walls of the growth substrate 1, the buffer layer 2, and the multilayer nitride semiconductor layer 6, the growth substrate 1 is smoothly peeled off. May be hindered. However, as shown in FIG. 22, by providing the protective film 15, for example, as shown in the schematic cross-sectional view of FIG. 24, the growth substrate 1, the buffer layer 2 and the multilayer nitride semiconductor layer 6 are joined to the side wall. Adhesion of the material 8 can be prevented.

Then, after removing the protective film 15 as shown in the schematic cross-sectional view of FIG. 25, the end portion of the buffer layer 2 and / or the multilayer nitride semiconductor layer 6 is formed as shown in the schematic cross-sectional view of FIG. Since one end is open, Al and nitrogen gas generated by thermal decomposition can be effectively released to the outside. Therefore, the growth substrate 1 can be smoothly peeled off by the irradiation of the above-mentioned light 10. When the protective film 15 is SiO ₂ , it can be removed by hydrofluoric acid.

Even when the protective film 15 is not formed, one end of the buffer layer 2 and / or the multilayer nitride semiconductor layer 6 may be open at the peripheral edge of the growth substrate 1. Although the above-mentioned opening can be realized by adjusting the bonding material 8, the yield is good and the above-mentioned opening configuration can be more easily realized by using the protective film 15.

It is also possible to open one end of the buffer layer 2 and / or the multilayer nitride semiconductor layer 6 by attaching a sample having a plurality of elements to a support substrate and then dividing the sample by scribe.

(Etching process)
After the growth substrate 1 is peeled off as described above, a part of the growth substrate 1 is thermally decomposed on the buffer layer 2, or when the entire buffer layer 2 is thermally decomposed, n of the multilayer nitride semiconductor layer 6. A substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is attached on the type nitride semiconductor layer 3. The oxygen concentration of the substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) has the distributions shown in FIGS. 27 (a) and 27 (b) as an example. There is. The substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) here is different from the natural oxide film.

That is, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen, and nitrogen) formed at a portion corresponding to the central region 42 of the irradiation region 12 of the light 10 shown in FIG. 27 (a). The oxygen concentration of is determined by a substance containing at least Al and oxygen (for example, Al and oxygen) formed at a portion corresponding to the peripheral region 41 of the irradiation region 12 per irradiation of light 10 shown in FIG. 27 (b). It is lower than the oxygen concentration of (a substance containing oxygen and nitrogen).

Then, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen, and nitrogen) formed in the central region 42 of the irradiation region 12 of the light 10 by applying an acid-based etchant treatment such as hydrofluoric acid). Is removed, and the buffer layer 2 or the n-type nitride semiconductor layer 3 of the multilayer nitride semiconductor layer 6 appears on the outermost surface. On the other hand, the peripheral region 41 of the irradiation region 12 of the light 10 contains a substance containing at least Al and oxygen containing a very small amount of oxygen (for example, Al, oxygen and nitrogen) for forming the convex region 21. The substance) can remain. A substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) can be removed by, for example, an acid-based etching solution. As described above, since the substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) has an oxygen concentration gradient, it is located in the peripheral region 41 of the irradiation region 12 of the light 10. Can only remain. Then, since the substance containing at least Al and oxygen (for example, the substance containing Al, oxygen and nitrogen) functions as a mask by the etching process described later, the convex region 21 having the convex portion and the convex shape A square-shaped structure including a non-convex region 22 surrounded by the region 21 can be formed. When the oxygen content of a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) is high, for example, a mixed aqueous solution of NH ₄ F, HF and H ₂ O, or HF. Etchant treatment using a mixed aqueous solution of H ₂ O and H ₂ O is effective. When the substance containing at least Al and oxygen further contains nitrogen, for example, phosphoric acid, a mixed solution of phosphoric acid and nitric acid, an alkaline solution such as potassium hydroxide (KOH), or treatment thereof is performed. Processing that combines multiple processes is effective.

The method of exposing the surface of the n-type nitride semiconductor layer 3 is not particularly limited, and examples thereof include a method of removing a part of the surface of the n-type nitride semiconductor layer 3 by dry etching or wet etching. Further, even a part of the surface of the n-type nitride semiconductor layer 3 can be removed by, for example, grinding and / or polishing. A substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) serves as a mask for dry etching such as RIE (Reactive Ion Etching) and ICP (Inductively coupled plasma). Fulfill. Also, in alkaline wet etching, it plays a role as a mask depending on conditions such as temperature, concentration and pH of the alkaline solution.

By the etching step described above, a convex portion having a slope as shown in FIGS. 5 to 7 can be formed, for example, a convex region 21 having a convex portion as shown in FIGS. 2 to 4. A square-shaped structure including the non-convex region 22 surrounded by the convex region 21 is formed.

(Formation of n-side electrode)
As the n-side electrode 19, for example, one in which at least one metal selected from the group consisting of Al, Ti, Mo and Au is laminated by a vapor deposition method or the like can be used. The n-side electrode 19 can be formed, for example, on at least a part of the surface of the n-type nitride semiconductor layer 3 and may be formed on the entire surface of the n-type nitride semiconductor layer 3 to improve light extraction. From the viewpoint, it may be formed in a mesh shape or the like.

Further, in the etching step of exposing the surface of the n-type nitride semiconductor layer 3, for example, when dry etching or wet etching is used, heat treatment can be performed in order to remove damage due to etching. Such heat treatment can be performed, for example, by heating at 400 ° C. for 5 minutes in a nitrogen atmosphere.

The wavelength (emission wavelength) of light emitted from the light emitting layer 4 by passing a current between the p-side electrode 7 and the n-side electrode 19 of the nitride semiconductor light emitting device of the embodiment manufactured as described above is It is preferably less than 320 nm, and more preferably 300 nm or less. When the emission wavelength of the nitride semiconductor light emitting device is less than 320 nm, particularly when it is 300 nm or less, the Al composition ratio of the n-type nitride semiconductor layer 3 of the nitride semiconductor light emitting device is as high as 25 atomic% or more. can do. In a nitride semiconductor light emitting device containing the n-type nitride semiconductor layer 3 having such a high Al composition ratio, the light irradiation region and the multilayer are formed without forming grooves at every shot interval of the laser beam as in the conventional case. It is preferable because the generation of cracks at the interface with the nitride semiconductor layer 6 can be suppressed and the effect of peeling off the large-area growth substrate 1 can be exhibited more remarkably.

<Action effect>
As described above, in the embodiment, a substance containing at least Al and oxygen on at least one surface of the buffer layer 2 and the n-type nitride semiconductor layer 3 containing Al for each irradiation of light 10. (For example, a substance containing Al, oxygen, and nitrogen) is formed. Then, by irradiating the light 10 while forming a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) by a step-and-repeat method or the like, laser light is emitted as in the conventional case. It is possible to suppress the occurrence of cracks at the interface between the irradiation region 12 of the light 10 and the multilayer nitride semiconductor layer 6 without forming grooves at each shot interval, and the large-area growth substrate 1 is peeled off. can do. This is because a shock wave generated by thermal decomposition of a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) and the buffer layer 2 by irradiation with light 10 adversely affects the in-plane direction. It is presumed that this is because it suppresses the effect of.

Then, in the etching step after the growth substrate 1 is peeled off, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) has a function as a mask for etching. Therefore, as described above, a grid-like structure including a convex region 21 having a convex portion and a non-convex region 22 surrounded by the convex region 21 is formed on the surface of the nitride semiconductor light emitting device. can do. With such a grid-like structure, the warping force of the multilayer nitride semiconductor layer 6 can be suppressed. The multilayer nitride semiconductor layer 6 after the peeling of the growth substrate 1 contains a large warping force due to a difference in the coefficient of thermal expansion at the time of raising and lowering the temperature of crystal growth. The warping force of the multilayer nitride semiconductor layer 6 is suppressed and flattened by joining to the support substrate 9 via the bonding material 8. Further, before the growth substrate 1 is peeled off, the warping force of the multilayer nitride semiconductor layer 6 is also suppressed by the growth substrate 1, but by peeling off the growth substrate 1, the multilayer nitride semiconductor layer 6 The force that suppresses the warp force is reduced. However, the reason is unknown by forming a square-shaped structure including a convex region 21 having a convex portion on the surface of the nitride semiconductor light emitting device and a non-convex region 22 surrounded by the convex region 21. However, the warping force of the multilayer nitride semiconductor layer 6 can be suppressed. The warping force of the multilayer nitride semiconductor layer 6 is a force that tends to peel off from the bonding to the support substrate 9 via the bonding material 8, and the above-mentioned grid-like structure is provided on the surface of the nitride semiconductor light emitting device. Since the warping force of the multilayer nitride semiconductor layer 6 can be suppressed, it is possible to suppress a failure of adhesion failure due to the bonding material 8, which is considered to be a factor of lowering the reliability of the nitride semiconductor light emitting device. It is possible to improve the reliability of the semiconductor light emitting device.

For the above reasons, in the embodiment, a large-area nitride semiconductor light emitting device can be manufactured with a high yield.

<Experimental example 1>
First, as shown in the schematic cross-sectional view of FIG. 28, a non-doped AlN buffer layer 102 having a thickness of about 5 μm and Si having a thickness of about 2 μm are placed on a commercially available sapphire substrate 101 having a thickness of 350 μm and subjected to double-sided polishing. Doped n-type Al _0.6 Ga _0.4 N layer 103, light emitting layer 104 in which 5 pairs of non-doped Al _0.4 Ga _0.6 N quantum well layer and non-doped Al _0.6 Ga _0.4 N barrier layer are alternately laminated, and Mg having a thickness of about 15 nm. Doped p-type Al _0.7 Ga _0.3 N carrier barrier layer, Mg-doped p-type Al _0.6 Ga _0.4 N layer with a thickness of about 10 nm, and Mg-doped p-type GaN contact layer with a thickness of about 20 nm are laminated in this order. The nitride semiconductor layer 105 was crystal-grown by the MOCVD method. Here, the multilayer nitride semiconductor layer 6 was composed of a laminate of the n-type Al _0.6 Ga _0.4 N layer 103, the light emitting layer 104, and the p-type nitride semiconductor layer 105.

Next, the wafer after laminating the p-type GaN contact layer was heat-treated at 800 ° C. for about 10 minutes in an oxygen atmosphere. As a result, Mg, which is a p-type dopant, in the p-type nitride semiconductor layer (p-type Al _0.7 Ga _0.3 N carrier barrier layer, p-type Al _0.6 Ga _0.4 N layer and p-type GaN contact layer) is activated. The function as a p-type semiconductor was expressed.

Next, using the laser scribe method, a chip was cut out from the wafer into a square shape having a side of 8 mm. Further, a tungsten plate having a square surface having a side of 15 mm and a thickness of 1.0 mm was prepared and organically washed.

Next, the chips and the tungsten plate produced as described above were held in a nitrogen atmosphere at a temperature of about 120 ° C. and baked for about 10 minutes.

Next, the p-side electrode 107 was formed by vapor-depositing Ni at a thickness of 20 nm and Au at a thickness of 50 nm on the surface of the p-type GaN contact layer of the chip after baking by an EB vapor deposition apparatus. .. Then, the chip after forming the p-side electrode 107 was left to stand in a nitrogen atmosphere at 500 ° C. for about 10 minutes to carry out an electrode alloy.

Next, as shown in FIG. 28, a support composed of a p-side electrode 107 formed on the multilayer nitride semiconductor layer 6 of the chip and a tungsten substrate using a thermosetting conductive adhesive 108 having a thickness of about 100 μm. It was bonded to the substrate 109. When joining the p-side electrode 107 and the support substrate 109, the conductive adhesive 108 was attached so as not to protrude.

Next, as shown in the schematic cross-sectional view of FIG. 29, by grinding the second surface 101b on the side opposite to the first surface 101a on the laminated side of the multilayer nitride semiconductor layer 106 of the sapphire substrate 101, The sapphire substrate 101 was thinned to a thickness of about 50 μm. After that, scratches generated by grinding on the second surface 101b of the sapphire substrate 101 were removed and polished to improve the mirror surface property of the rough second surface 101b after grinding.

Next, by the step-and-repeat method shown in FIG. 21, the second surface 101b of the sapphire substrate 101 is irradiated with light 10 which is a laser beam in the directions of arrows 13a, 13b, 13c, and 13d of FIG. The entire surface of the surface was irradiated with light 10. At this time, the shape of the irradiation region 12 per one irradiation of the light 10 was shaped into a square having a side length W1 of 500 μm by using a metal mask. The adjacent irradiation regions 12 of the light 10 did not overlap, and the protrusion width W2 from the peripheral edge of the multilayer nitride semiconductor layer 6 of the irradiation region 12 was 100 μm.

Under the above conditions, an experiment was conducted on whether or not the sapphire substrate 101 was peeled off. As a result, when it is once ranges irradiation energy density of 1500 mJ / cm ² or more 5000 mJ / cm ² or less per irradiation of light 10, separation of the sapphire substrate 101 was confirmed.

The schematic plan view of FIG. 30 shows a surface observation image of the surface of the chip after peeling of the sapphire substrate 101 with an optical microscope. As shown in FIG. 30, on the surface of the chip, a convex region 21 having a convex portion formed by irradiation with light 10 and a concave non-convex region 22 surrounded by the convex region 21. It was observed that a grid-like structure including and was formed. By peeling off the sapphire substrate 101 while forming such a grid-like structure, even when a large-area sapphire substrate 101 is used, the irradiation region 12 of the light 10 and the multilayer nitride semiconductor layer 6 are formed. It has been found that the sapphire substrate 101 can be peeled off without causing cracks on the boundary surface of the sapphire substrate 101.

The X-ray diffraction spectrum obtained by injecting X-rays from the p-type GaN contact layer side before the sapphire substrate 101 is peeled off, and the X-rays from the AlN buffer layer 102 side after the sapphire substrate 101 is peeled off. The results of 2θ / ω of the X-ray diffraction spectrum obtained by injecting sapphire were almost the same.

Therefore, it was confirmed that the sapphire substrate 101 having a large area can be peeled off by the above method without causing significant crystal deterioration. Further, by the above method, it was possible to confirm the peeling of the sapphire substrate 101 having a maximum diameter of 2 inches.

<Experimental example 2>
A chip was prepared under the same method and conditions as in Experimental Example 1, and the sapphire substrate 101 was peeled from the chip. Then, the composition analysis of the convex portion forming the convex region 21 on the surface of the chip after the peeling of the sapphire substrate 101 was performed. The result is shown in FIG.

FIG. 31 shows the results of composition analysis in which the convex portion forming the convex region 21 on the surface of the chip was measured by an energy dispersive X-ray analyzer (SEM-EDX) attached to a scanning electron microscope (SEM). Based on the results shown in FIG. 31, when the atomic number ratio (atomic%) of the elements constituting the convex portion was calculated by the conversion software, Al was 27.5 in the peripheral region of the irradiation region 12 of the light 10. Atomic%, oxygen was 42.6 atomic%, and nitrogen was 29.8 atomic%. On the other hand, in the central region of the irradiation region 12 of the light 10, Al was 41.9 atomic%, oxygen was 23.4 atomic%, and nitrogen was 34.5 atomic%. Therefore, it was confirmed that an oxygen concentration gradient in which the oxygen concentration of the convex portion forming the convex region 21 on the surface of the chip increases is formed from the central region to the peripheral region of the irradiation region 12 of the light 10.

That is, after polishing the sapphire substrate 101, the sapphire substrate 101 peeled off by irradiating the second surface 101b of the sapphire substrate 101 with a laser beam has the shapes shown in FIGS. 14 (b) and 14 (c). Become. As a result, in the peripheral region of the irradiation region 12 of the light 10, the distance between the sapphire substrate 101 and the AlN buffer layer 102 is narrower than that of the central region of the irradiation region 12 of the light 10, so that the AlN buffer layer 102 Absorbs the laser beam and generates heat, and when a part of the sapphire substrate is thermally decomposed, a part of the sapphire substrate 101 is also thermally decomposed to supply a large amount of oxygen, and the oxygen concentration in the convex portion becomes high. It is considered to be. On the other hand, in the central region of the irradiation region 12 of the light 10, it is considered that oxygen in the atmosphere is mainly taken into the convex portion.

For comparison, the above composition analysis using SEM-EDX was also performed on a sample in which AlN was grown on the sapphire substrate 101 and a GaN substrate under the same conditions, but oxygen could not be detected. It was. Therefore, it can be determined that the convex portion having oxygen detected in Experimental Example 2 is not a natural oxide film.

<Experimental example 3>
A chip was prepared under the same method and conditions as in Experimental Example 1, and the sapphire substrate 101 was peeled from the chip. Then, the acid treatment of the convex portion forming the convex region 21 on the surface of the chip after the peeling of the sapphire substrate 101 and the adaptability as a mask to etching were examined.

FIG. 32 shows the results of composition analysis measured by SEM-EDX in the central region of the irradiation region 12 of the light 10 after immersing the chip in hydrofluoric acid at room temperature for about 10 minutes. As shown in FIG. 32, it was confirmed that almost no oxygen was present in the central region of the irradiation region 12 of the light 10. From this result, it can be seen that the convex portion formed in the central region of the irradiation region 12 of the light 10 shown in FIG. 30 can be almost removed by the hydrofluoric acid treatment.

On the other hand, when the composition analysis of SEM-EDX was similarly performed on the peripheral region of the irradiation region 12 of the light 10, oxygen of several atomic% or less was detected. Then, for example, when chlorine-based dry etching is performed on the surface of the chip after the hydrofluoric acid treatment, the convex portion containing a small amount of oxygen remaining in the peripheral region of the irradiation region 12 of the light 10 is formed. A grid-like structure including a convex region 21 having a convex portion as shown in FIG. 2 and a concave non-convex region 22 surrounded by the convex region 21 in order to act as a mask in the initial stage of etching. Was able to form. As an example of the convex portion of the convex region 21 of the square-shaped structure formed in this manner, a triangular portion having a height of about 400 nm and a width of about 40 μm was formed.

Similarly, as an alkaline etching, the above-mentioned hydrofluoric acid-treated chip is immersed in a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (developing solution "NMD-3") at about 50 ° C. for several minutes. When etching was attempted, it was confirmed that a grid-like structure including a convex region 21 having a convex portion and a concave non-convex region 22 surrounded by the convex region 21 could be formed.

<Experimental Example 4>
In the same manner as in Experimental Example 1, a p-side electrode was formed on the surface of the p-type GaN contact layer, and an electrode alloy was carried out.

Next, as shown in FIG. 28, a support composed of a p-side electrode 107 formed on the multilayer nitride semiconductor layer 106 of the chip and an Al substrate using a thermosetting conductive adhesive 108 having a thickness of about 100 μm. It was bonded to the substrate 109. When joining the p-side electrode 107 and the support substrate 109, the conductive adhesive 108 was attached so as not to protrude.

Next, as shown in FIG. 29, the sapphire substrate 101 is 60 μm by grinding the second surface 101b on the side opposite to the first surface 101a on the laminated side of the multilayer nitride semiconductor layer 106 of the sapphire substrate 101. It was thinned to a certain thickness. After that, scratches generated by grinding on the second surface 101b of the sapphire substrate 101 are removed and polished to reduce the thickness to about 55 μm, and the mirror surface of the rough second surface 101b after grinding is improved. I let you.

Next, by the step-and-repeat method shown in FIG. 21, the second surface 101b of the sapphire substrate 101 is irradiated with light 10 which is a laser beam in the directions of arrows 13a, 13b, 13c, and 13d of FIG. The entire surface of the surface was irradiated with light 10. At this time, the shape of the irradiation region 12 per one irradiation of the light 10 was shaped into a square having a side length W1 of 500 μm by using a metal mask. The adjacent irradiation regions 12 of the light 10 did not overlap, and the protrusion width W2 from the peripheral edge of the multilayer nitride semiconductor layer 6 of the irradiation region 12 was 100 μm.

Under the above conditions, an experiment was conducted on whether or not the sapphire substrate 101 was peeled off. As a result, when it is once ranges irradiation energy density of 1500 mJ / cm ² or more 5000 mJ / cm ² or less per irradiation of light 10, separation of the sapphire substrate 101 was confirmed.

When the light 10 was irradiated with a laser beam having an excessive irradiation energy density equal to or higher than the irradiation energy density at which the peeling of the sapphire substrate 101 could be confirmed by the above method, the surface of some chips was as shown in FIG. 33. The state of scraping 123 of the nitride semiconductor was observed. It has been found that the scraping 123 of the nitride semiconductor is a phenomenon that is often seen mainly at the contacts of the adjacent irradiation regions 12. The cause is that the portion where the nitride semiconductor scraping 123 occurs is irradiated with laser light four times in the vicinity, so that the nitride semiconductor is scraped due to the influence of shock waves and heat generation at that time. It is considered that 123 may occur.

Therefore, the method of irradiating the laser beam was changed to the method shown in FIG. In this case, the number of times of irradiation of the laser beam irradiated to one place can be reduced to three times. Therefore, when the laser beam is irradiated with the same irradiation energy density as described above, the nitride semiconductor is scraped. 123 was not found. It has been confirmed that by using such a laser beam irradiation method, the allowable range of energy fluctuation of the excimer laser beam can be widened, and the decrease in the yield of the nitride semiconductor light emitting device can be suppressed.

<Experimental Example 5>
In Experimental Example 5, the shape of the light 10 per irradiation was set to a hexagonal shape as shown in FIG. 18, and the same experiment as in Experimental Example 4 was performed. As a result, the same result as in Experimental Example 4 was obtained. Was done. In this case as well, the number of times of irradiation of the laser beam irradiated to one place can be reduced to three times. Therefore, when the laser beam is irradiated with the same irradiation energy density as described above, the nitride semiconductor is scraped 123. Was not found. It has been confirmed that by using such a laser beam irradiation method, the allowable range of energy fluctuation of the excimer laser beam can be widened, and the decrease in the yield of the nitride semiconductor light emitting device can be suppressed.

<Experimental example 6>
The chip from which the sapphire substrate 101 was peeled off in Experimental Example 4 was immersed in hydrofluoric acid for 10 minutes, and then washed with pure water for 10 minutes. The size and shape of the surface of the chip at this time was a square with a side of 3 mm.

Next, etching is performed by the existing RIE method to etch the non-doped AlN buffer layer 102 having a thickness of about 5 μm and the Si-doped n-type Al _0.6 Ga _0.4 N layer 103 having a thickness of about 2 μm to a thickness of about 500 nm. The n-type Al _0.6 Ga _0.4 N layer 103 was cueed.

Next, on the surface of the chip after etching, as shown in the schematic plan view of FIG. 34, a convex region 21 having a convex portion and a concave non-convex region 22 surrounded by the convex region 21 A grid-like structure including and was formed.

Next, as shown in the schematic cross-sectional view of FIG. 35, the surface of the non-convex region 22 of the n-type Al _0.6 Ga _0.4 N layer 103 is arranged so that the convex portion of the convex region 21 is opened upward. An n-side electrode 119 composed of Ti / Al mesh electrodes is formed on the top. Then, the electrode alloy is performed by heating the n-side electrode 119 at 400 ° C. for 5 minutes in a nitrogen atmosphere. As a result, the nitride semiconductor light emitting device of Experimental Example 6 was produced.

As a comparative example, the same as in Experimental Example 6 except that the chip from which the sapphire substrate 101 was peeled off was immersed in hydrofluoric acid for 10 minutes, phosphoric acid for 10 minutes, and potassium hydroxide aqueous solution for 2 minutes. A nitride semiconductor light emitting device of a comparative example was produced. In the nitride semiconductor light emitting device of the comparative example, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) that serves as a mask for etching was removed, so that a grid-like structure appeared. I didn't.

As a result of comparing the current light output characteristics of the nitride semiconductor light emitting device of Experimental Example 6 and Comparative Example, the nitride semiconductor light emitting device of Experimental Example 6 was compared with the nitride semiconductor light emitting device of Comparative Example under the same current injection conditions. As a result, the light output is 1.2 times higher. This is because the surface of the nitride semiconductor light emitting device of Experimental Example 6 has a convex region 21 having a convex portion which is not formed on the surface of the nitride semiconductor light emitting device of the comparative example, and the convex region 21. It is considered that this is because the light extraction efficiency is improved because the square-shaped structure including the concave non-convex region 22 surrounded is formed.

Further, the light emitted from the light emitting layer 104 of the nitride semiconductor light emitting device of Experimental Example 6 and passing through the convex portion of the convex region 21 on the surface of the n-type Al _0.6 Ga _0.4 N layer 103 is n-type Al _0.6. Since air is passed from the Ga _0.4 N layer 103 through the AlN buffer layer 102, the change in the refractive index becomes gradual. Therefore, it is considered that the influence of reflection at the interface is suppressed and the light can be efficiently extracted as compared with the case of the comparative example in which the light is directly emitted from the n-type Al _0.6 Ga _0.4 N layer 103 to the air.

<Experimental Example 7>
The nitride semiconductor light emitting device of Experimental Example 7 was produced in the same manner as in Experimental Example 6 except that the shape and size of the irradiation region 12 per irradiation of light 10 was a square having a side of 200 μm. Then, in the same manner as in Experimental Example 6, the current light output characteristics of the nitride semiconductor light emitting device of Experimental Example 7 were measured. As a result, the same result as in Experimental Example 6 was obtained in Experimental Example 7. Further, the shape and size of the irradiation region 12 per irradiation of the light 10 was changed from a square having a side of 500 μm to a square having a side of 200 μm, and the same result as in Experimental Example 6 was obtained.

<Experimental Example 8>
The current light output of the nitride semiconductor light emitting device of Experimental Example 8 is the same as that of Experimental Example 6 except that the shape and size of the irradiation region 12 per irradiation of light 10 is a hexagon having a side of 250 μm. The characteristics were measured. As a result, the same result as in Experimental Example 6 was obtained in Experimental Example 8.

<Experimental Example 9>
The shape and size of the surface of the chip are a square with a side of 5 mm, a square with a side of 10 mm, a square with a side of 30 mm, and a square with a side of 2 inches. The sapphire substrate 101 is similar to Experimental Examples 1 to 8. When the sapphire substrate 101 was peeled off, the sapphire substrate 101 could be peeled off without forming cracks.

<Additional notes>
(Appendix 1)
The nitride semiconductor light emitting device according to Appendix 1 is a nitride semiconductor including a first conductive type nitride semiconductor layer, a light emitting layer, and a multilayer nitride semiconductor layer including a second conductive type nitride semiconductor layer in this order. The light emitting device has a square-shaped structure including a convex region having a convex portion and a non-convex region surrounded by the convex region on the surface of the nitride semiconductor light emitting device. Since the warp force of the multilayer nitride semiconductor layer can be suppressed by such a grid-like structure, it is possible to suppress a failure of adhesion failure due to repeated operation of the nitride semiconductor light emitting device, and thus the nitride semiconductor. The reliability of the light emitting element can be improved.

(Appendix 2)
The nitride semiconductor light emitting device according to Appendix 2 is the nitride semiconductor light emitting device according to Appendix 1, wherein the convex region occupies 5% or more and 40% or less of the total area of the surface of the nitride semiconductor light emitting device. When the convex region occupies 5% or more and 40% or less of the total area of the surface of the n-type nitride semiconductor layer which is the surface of the nitride semiconductor light emitting device, the convex region and the non-convex region are defined. The effect of being able to manufacture a large-area nitride semiconductor light-emitting device with good yield due to the formation of the including square-shaped structure can be more effectively exhibited, and on the surface of the n-type nitride semiconductor layer. When the n-side electrode is formed in a mesh shape, the disconnection of the n-side electrode can be suppressed more effectively.

(Appendix 3)
In the nitride semiconductor light emitting device according to Appendix 3, the convex portion has a lower surface, the width of the lower surface is 5 μm or more and 100 μm or less, and the height of the convex portion is 1000 nm or less. The nitride semiconductor light emitting device according to the above. In this case, even when the n-side electrode is formed so as to straddle the convex portion of the convex region, the occurrence of disconnection in the n-side electrode can be suppressed, and the n-side electrode is formed. It is possible to suppress adverse effects in the process process (non-uniformity of resist coating, defects in the photolithography process, etc.). Further, in this case, a large-area nitride semiconductor light emitting device can be manufactured more stably. Further, in this case, when the n-type nitride semiconductor layer is exposed on the outermost surface of the nitride semiconductor light emitting device, the formation area of the n-side electrode can be expanded, so that the contact resistance of the n-side electrode can be expanded. Can be suppressed.

(Appendix 4)
The nitride semiconductor light emitting device according to Appendix 4 is the nitride semiconductor light emitting device according to Appendix 1 or Appendix 2, which has one point where convex regions merge from three directions in a plan view. In this case, the number of times of overlapping light irradiation can be reduced, and the adverse effect caused by the light irradiation damage can be suppressed, so that a large-area nitride semiconductor light emitting device can be manufactured with good yield.

(Appendix 4-1)
The nitride semiconductor light emitting device according to Appendix 4-1 is a column when the non-convex region surrounded by the convex region having the convex portion is rectangular or square and is aligned in the row direction. The nitride semiconductor light emitting device according to Appendix 4, which is deviated in the direction and is deviated in the row direction when aligned in the column direction. As a result, the number of times of overlapping light irradiation can be reduced, and adverse effects caused by light irradiation damage can be suppressed, so that a large-area nitride semiconductor light emitting device can be manufactured with good yield.

(Appendix 4-2)
In the nitride semiconductor light emitting device according to Appendix 4-2, the non-convex region surrounded by the convex region having the convex portion has a hexagonal shape, and when they are aligned in the row direction, they are displaced in the column direction. The nitride semiconductor light emitting device according to Appendix 4, which is deviated in the row direction when aligned in the column direction. As a result, the number of times of overlapping light irradiation can be reduced, and adverse effects caused by light irradiation damage can be suppressed, so that a large-area nitride semiconductor light emitting device can be manufactured with good yield. Further, since the arrangement shape of the irradiation region is contrasted, the influence of light irradiation on the nitride semiconductor can be uniformly suppressed, so that a large-area nitride semiconductor light emitting device can be manufactured with a high yield.

(Appendix 5)
The method for manufacturing a nitride semiconductor light emitting element according to Appendix 5 includes a step of forming an Al-containing nitride semiconductor layer on the first surface of a growth substrate and a method of forming an Al-containing nitride semiconductor layer on the Al-containing nitride semiconductor layer. A step of forming a multilayer nitride semiconductor layer in which a first conductive nitride semiconductor layer, a light emitting layer, and a second conductive nitride semiconductor layer are arranged in this order, and a substrate supporting the multilayer nitride semiconductor layer. After the step of joining on the surface and the step of joining on the surface of the support substrate, the step of thinning the growth substrate from the second surface side opposite to the first surface of the growth substrate and the growth. A step of peeling the growth substrate by irradiating light from the second surface side of the substrate and absorbing at least a part of the light into a layer made of a nitride semiconductor containing Al, and a step of peeling the growth substrate. In the step of peeling the growth substrate, which includes a step of etching after the step, at least one surface of the nitride semiconductor layer containing Al and the first conductive type nitride semiconductor layer contains at least Al and oxygen. A substance (for example, a substance containing Al, oxygen, and nitrogen) is formed, and in the etching process, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen, and nitrogen) is used as a mask. , A nitride semiconductor light emitting element in which a grid-like structure including a convex region having a convex portion and a non-convex region surrounded by the convex region is formed on the surface of the first conductive nitride semiconductor layer. It is a manufacturing method. In this case, by irradiating light while forming a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) by a step-and-repeat method or the like, as in the conventional case. It is possible to suppress the occurrence of cracks at the interface between the light irradiation region and the multilayer nitride semiconductor layer without forming grooves at each shot interval of the laser beam, and to peel off a large-area growth substrate. Can be done. Then, in the etching step after the growth substrate is peeled off, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) has a function as a mask for etching. Therefore, it is possible to form a square-shaped structure including a convex region having a convex portion and a non-convex region surrounded by the convex region on the surface of the nitride semiconductor light emitting device. Since the warp force of the multilayer nitride semiconductor layer can be suppressed by such a grid-like structure, it is possible to suppress a failure of adhesion failure due to repeated operation of the nitride semiconductor light emitting device, and thus the nitride semiconductor. The reliability of the light emitting element can be improved.

(Appendix 6-1)
In the method for manufacturing a nitride semiconductor light emitting device according to Appendix 6-1, the shape of the irradiation region per irradiation of light is a square having at least one side length of 100 μm or more and 2000 μm or less, or one side length. The method for manufacturing a nitride semiconductor light emitting device according to Appendix 5, which is a square of 100 μm or more and 2000 μm or less. In this case, since the number of times of irradiation of light for peeling off the large-area growth substrate can be reduced, the manufacturing efficiency of the nitride semiconductor light emitting device can be improved, and it is necessary for peeling off the growth substrate. The energy density of light can be easily obtained.

(Appendix 6-2)
The nitride semiconductor light emitting device according to Appendix 6-2 is described in Appendix 5 in which the shape of the irradiation region per irradiation of light is a hexagon having a side length of 50 μm or more and 2000 μm or less. This is a method for manufacturing a semiconductor light emitting device. In this case, since the number of times of irradiation of light for peeling off the large-area growth substrate can be reduced, the manufacturing efficiency of the nitride semiconductor light emitting device can be improved, and it is necessary for peeling off the growth substrate. The energy density of light can be easily obtained.

(Appendix 7)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 7 is a substance containing at least Al and oxygen (for example, Al, oxygen, and nitrogen) generated due to the shape of the irradiation region per one irradiation of light. The oxygen concentration in the peripheral region of the irradiation region per irradiation of light is higher than the oxygen concentration in the central region in the oxygen concentration of (substance containing), whichever of Appendix 5, Appendix 6-1 or Appendix 6-2. The method for manufacturing a nitride semiconductor light emitting device according to one of the above. By performing the acid-based etchant treatment, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) in the central region of the irradiation region per one irradiation of light is removed, and the peripheral edge thereof is removed. Only substances containing at least Al and oxygen in the region (for example, substances containing Al, oxygen and nitrogen) can be left, and substances containing at least Al and oxygen in the peripheral region (for example, Al, oxygen and nitrogen) can be left. A substance containing and) can function as a mask against etching.

(Appendix 8)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 8 is described in any one of Appendix 5, Appendix 6-1 and Appendix 6-2 or Appendix 7 in which the nitride semiconductor layer containing Al is AlN. This is a method for manufacturing a nitride semiconductor light emitting device. In this case, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) can be effectively functioned as a mask in the etching step.

(Appendix 9)
In the method for manufacturing a nitride semiconductor light emitting device according to Appendix 9, the total thickness of the Al-containing nitride semiconductor layer and the multilayer nitride semiconductor layer formed on the first surface of the growth substrate is 3 μm. The method for manufacturing a nitride semiconductor light emitting device according to any one of Supplementary note 5, Supplementary note 6-1 and Supplementary note 6-2, Supplementary note 7 or Supplementary note 8 described above. In this case, in the step of peeling off the growth substrate, the nitride semiconductor layer containing Al is thermally decomposed by irradiation with light, and the growth substrate and the nitride containing Al in which all or a part thereof are decomposed. It is possible to suppress the adverse effect of the shock wave, which is considered to be generated when the semiconductor layer is peeled off, on the light emitting layer.

(Appendix 10)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 10 can be applied to any one of Appendix 5, Appendix 6-1 and Appendix 6-2, Appendix 7, Appendix 8 or Appendix 9 in which the growth substrate is a sapphire substrate. The method for manufacturing a nitride semiconductor light emitting device according to the above. The sapphire substrate is suitable as a material for a growth substrate because it has a high transmittance for light in a wide wavelength region ranging from 150 nm to 1000 nm, for example.

(Appendix 11)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 11 is any one of Appendix 5, Appendix 6-1 and Appendix 6-2, Appendix 7, Appendix 8, Appendix 9 or Appendix 10 in which the wavelength of light is 200 nm or less. The method for manufacturing a nitride semiconductor light emitting device according to one. When the wavelength of light is 200 nm or less, light decomposes oxygen in the atmosphere, so that a substance containing at least Al and oxygen (for example, Al) generated during thermal decomposition of the nitride semiconductor layer containing Al is generated. A substance containing oxygen and nitrogen) can take in more oxygen. As a result, a substance containing at least Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) can be formed in a desired shape, so that a convex region is formed on the surface of the nitride semiconductor light emitting device. The non-convex shape region can be formed into a desired shape. When the wavelength of light is 200 nm or less, when the growth substrate is a sapphire substrate, the light is suitably transmitted through the growth substrate, and the buffer layer made of a nitride semiconductor containing Al emits light. It tends to absorb efficiently and decompose thermally.

(Appendix 12)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 12 removes at least a part of a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) by hydrofluoric acid treatment. The method for manufacturing a nitride semiconductor light emitting device according to any one of Supplementary note 6-1 and Supplementary note 6-2, Supplementary note 7, Supplementary note 8, Supplementary note 9, Appendix 10 or Supplementary note 11. In this case, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) in the central region of the light irradiation region is removed, and at least Al is removed in the peripheral region of the light irradiation region. A substance containing oxygen and oxygen (for example, a substance containing Al, oxygen and nitrogen) can be left as an etching mask.

(Appendix 13)
The method for manufacturing a nitride semiconductor light emitting device according to Appendix 13 removes at least a part of a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) by a phosphoric acid treatment. The method for manufacturing a nitride semiconductor light emitting device according to any one of Supplementary note 6-1 and Supplementary note 6-2, Supplementary note 7, Supplementary note 8, Supplementary note 9, Appendix 10, Appendix 11 or Appendix 12. In this case, at least a substance containing Al and oxygen (for example, a substance containing Al, oxygen and nitrogen) left in the peripheral region of the light irradiation region can be completely removed.

Although the embodiments and experimental examples of the present invention have been described above, it is planned from the beginning that the configurations of the above-described embodiments and experimental examples are appropriately combined.

It should be considered that the embodiments and experimental examples disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The present invention may be used in a method for manufacturing a nitride semiconductor light emitting device and a nitride semiconductor light emitting device.

1 Growth substrate, 1a 1st surface, 1b 2nd surface, 2 buffer layer, 3n type nitride semiconductor layer, 4 light emitting layer, 5p type nitride semiconductor layer, 6 multilayer nitride semiconductor layer, 7p Side electrode, 8 bonding material, 9 support substrate, 10 light, 11 space, 12 irradiation area, 13, 13a, 13b, 13c, 13d arrow, 14 scratch scratch, 15 protective film, 19 n side electrode, 21 convex area, 22 Non-convex region, 23 Confluence, 31 Top surface, 32 Bottom surface, 33 Slope, 41 Peripheral region, 42 Central region, 51 4-point concentration location, 52 3-point concentration location, 101 Sapphire substrate, 101a 1st surface, 101b Second surface, 102 AlN buffer layer, 103 n type Al _0.6 Ga _0.4 N layer, 104 light emitting layer, 105 p type nitride semiconductor layer, 106 multilayer nitride semiconductor layer, 107 p side electrode, 108 conductive adhesive, 109 Support substrate, 119n side electrode, 123 Shaving of nitride semiconductor.

Claims (7)

A nitride semiconductor light emitting device including a multilayer nitride semiconductor layer including a first conductive type nitride semiconductor layer, a light emitting layer, and a second conductive type nitride semiconductor layer in this order.
The surface of the multilayer nitride semiconductor layer has a grid-like structure including a convex region having a convex portion and a non-convex region surrounded by the convex region.
The convex portion has a lower surface and has a lower surface.
The width of the lower surface is 5 μm or more and 100 μm or less.
The height of the convex portion is 1000 nm or less,
The convex region, Ri regions der having said convex portion from the surface of the multilayer nitride semiconductor layer projecting above said non-convex regions,
Wherein the non-convex region, Ru comprise an electrode formed in a mesh shape, the nitride semiconductor light emitting device. The nitride semiconductor light emitting device according to claim 1, wherein the convex region occupies 5% or more and 40% or less of the area of the entire surface of the nitride semiconductor light emitting device. The nitride semiconductor light emitting device according to claim 1 or 2, wherein the convex region has one point where the convex regions meet from three directions in a plan view. The nitride semiconductor light emitting device according to any one of claims 1 to 3, which has a substance containing at least Al, oxygen, and nitrogen on the surface of the convex portion. The nitride semiconductor light emitting device according to any one of claims 1 to 4 , wherein the non-convex region of the multilayer nitride semiconductor layer is made of an n-type nitride semiconductor. A step of forming an Al-containing nitride semiconductor layer on the first surface of the growth substrate, and
A multilayer nitride semiconductor layer in which a first conductive type nitride semiconductor layer, a light emitting layer, and a second conductive type nitride semiconductor layer are arranged in this order is formed on the Al-containing nitride semiconductor layer. Process and
The step of joining the multilayer nitride semiconductor layer on the surface of the support substrate,
After the step of joining onto the surface of the support substrate, a step of thinning the growth substrate from the second surface side opposite to the first surface of the growth substrate.
A step of peeling off the growth substrate by irradiating light from the second surface side of the growth substrate and absorbing at least a part of the light into a layer made of a nitride semiconductor containing Al.
Including a step of etching after the step of peeling the growth substrate.
In the step of peeling the growth substrate, a substance containing at least Al and oxygen is formed on at least one surface of the Al-containing nitride semiconductor layer and the first conductive type nitride semiconductor layer.
In the etching step, the substance containing at least Al and oxygen is used as a mask, and the surface of the first conductive nitride semiconductor layer is surrounded by a convex region having a convex portion and the convex region. A method for manufacturing a nitride semiconductor light emitting device, in which a grid-like structure including a non-convex region is formed. The method for producing a nitride semiconductor light emitting device according to claim 6 , wherein the substance containing at least Al and oxygen further contains nitrogen.