JP6841214B2 - Manufacturing method of light emitting element - Google Patents

Description

The present invention relates to a method for manufacturing a light emitting element, and more particularly to a method for scribe braking the light emitting element from a semiconductor substrate.

Products such as chip-on-board (COB) are excellent in heat dissipation from LED elements, and are LED chip mounting methods used in applications such as lighting. When mounting an LED on a COB or the like, flip mounting in which the chip is directly bonded to the board is indispensable. In order to realize flip mounting, it is necessary to manufacture a flip chip provided with energizing pads having different polarities on one surface of the light emitting element. Further, the surface opposite to the surface on which the energizing pad is provided needs to be made of a material having a light extraction function.

When a flip chip is made of yellow to red LEDs, an AlGaInP-based material is used for the light emitting layer. Since the AlGaInP-based material does not have bulk crystals and the LED portion is formed by the epitaxial method, a material different from AlGaInP is selected as the starting substrate. GaAs and Ge are often selected as the starting substrate, and since these substrates have the property of absorbing light with respect to visible light, the starting substrate is removed when the flip chip is manufactured. However, since the epitaxial layer forming the light emitting layer is an extremely thin film, it cannot stand on its own after the starting substrate is removed. Therefore, it is necessary to replace the starting substrate with a material / configuration in which the light emitting layer is transparent to the emission wavelength, has a function as a window layer, and has a function as a support substrate having a sufficient thickness for self-supporting. is there.

Patent Document 1 discloses a technique of adhering a light emitting layer to a transparent substrate having a function of a window layer and a supporting substrate with an adhesive such as BCB (benzocyclobutene) to form an LED. A sapphire substrate or a quartz substrate is often selected as the transparent substrate in terms of flatness, hardness, and cost. After adhering the light emitting layer, the transparent substrate is cut to make a die to make a light emitting element. However, in order to minimize the carfloss at the time of cutting, it is common to make a die by scribe braking instead of using a blade. .. In the case of a sapphire substrate or a quartz substrate, the scribe method is generally performed by an ablation laser.

At this time, the laser wavelength used is an ultraviolet wavelength region having a wavelength shorter than 360 nm in order to ablate the transparent substrate with respect to visible light. The BCB adhesive is transparent to visible light and has an absorption band for wavelengths in the ultraviolet region. That is, the absorption wavelength bands of the BCB adhesive and the visible / transparent substrate are close to each other. When a substrate in which a light emitting layer and a visible transparent substrate are joined with an adhesive having a light absorption band in the ultraviolet region is screened with a laser, not only the transparent substrate but also a visible transparent adhesive such as BCB adhesive absorbs laser energy. There was a problem that it was destroyed and peeled off from the joint.

JP-A-2004-158823

The present invention has been made in view of the above problems, and in the scribing braking step of scribing a substrate in which a light emitting layer and a transparent substrate are joined with an adhesive having a light absorption band in the ultraviolet region with a laser, the visible transparent adhesive is a laser. An object of the present invention is to provide a method for manufacturing a light emitting element that absorbs energy, is destroyed, and suppresses peeling from a joint.

In order to achieve the above object, the present invention is a method for manufacturing a light emitting element.
(1) A step of forming a laminated structure including a light emitting layer portion in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially laminated by epitaxial growth on a starting substrate to produce a wafer for a light emitting element.
(2) Process of preparing the support substrate,
(3) A step of adhering the support substrate to the wafer for a light emitting element via an adhesive layer to prepare a bonded substrate.
(4) In the bonding substrate, a step of removing the starting substrate to expose the first semiconductor layer.
(5) A step of removing at least the first semiconductor layer and the active layer to form a removed portion in a part of the bonded substrate.
(6) The bonding substrate is formed by forming a first ohmic electrode on the surface of the first semiconductor layer and a second ohmic electrode on the surface of the removal portion, and (7) a scribing braking method using laser light. The process of separating the light emitting element into a die shape from
Provided is a method for manufacturing a light emitting element, which comprises the above and removes the adhesive layer in the scribing region in advance before scribing.

According to such a method for manufacturing a light emitting element, it is possible to prevent the adhesive from being broken and peeling from the joint portion by preventing the adhesive layer from being present in the scribing region in the scribe braking step. it can.

Further, in the step (7), it is preferable to remove the adhesive layer in the scribe region before performing scribe.

According to such a method for manufacturing a light emitting element, it is possible to relatively easily prevent the adhesive from being present in the scribe region.

Further, in the step (2), it is preferable that the support substrate has an adhesive layer, and the adhesive layer is removed so that the adhesive layer does not exist in the scribe region. ..

Even in this way, it is relatively easy to prevent the adhesive from being present in the scribe region.

Further, it is preferable that the width of the region where the adhesive does not exist is 20 μm or more in the direction perpendicular to the scribe direction.

If the width of the region where such an adhesive does not exist is set, a dramatic peeling improvement effect can be obtained.

As described above, according to the method for manufacturing a light emitting element of the present invention, it is visible in the scribing / braking step of scribing a substrate in which a light emitting layer and a transparent substrate are joined with an adhesive having a light absorption band in the ultraviolet region with a laser. It is possible to prevent the transparent adhesive from absorbing the laser energy, being destroyed, and peeling off from the joint.

It is explanatory drawing of the scribe in the manufacturing method of the light emitting element of this invention. It is the schematic of the light emitting element wafer manufactured in 1st Embodiment. It is the schematic when the 1st junction layer was formed in the light emitting element wafer produced in 1st Embodiment. It is the schematic of the support substrate prepared in 1st Embodiment. It is the schematic of the bonding substrate formed in 1st Embodiment. It is the schematic of the bonding substrate which exposed the 1st semiconductor layer of 1st Embodiment. It is the schematic of the bonded substrate which formed the removal part of 1st Embodiment. It is the schematic of the bonding substrate which formed the opening in the dielectric layer of 1st Embodiment. It is the schematic of the bonding substrate which formed the 1st ohmic electrode and the 2nd ohmic electrode of 1st Embodiment. It is the schematic of the bonding substrate which formed the coating part and the opening part of the resist of 1st Embodiment. It is the schematic of the bonding substrate which formed the exposed part of 1st Embodiment. It is the schematic of the scribed bonding substrate of 1st Embodiment. It is the schematic of the light emitting element wafer manufactured in the 2nd Embodiment. It is the schematic when the first junction layer was formed on the light emitting element wafer produced in the 2nd Embodiment. It is the schematic of the support substrate prepared in the 2nd Embodiment. It is the schematic of the support substrate which formed the pattern in the adhesive layer of 2nd Embodiment. It is the schematic of the bonding substrate formed in the 2nd Embodiment. It is the schematic of the bonding substrate which exposed the 1st semiconductor layer of 2nd Embodiment. It is the schematic of the bonding substrate which formed the removal part of the 2nd Embodiment. It is the schematic of the bonding substrate which formed the opening in the dielectric layer of the 2nd Embodiment. It is the schematic of the bonding substrate which formed the 1st ohmic electrode and the 2nd ohmic electrode of the 2nd Embodiment. It is the schematic of the bonding substrate which formed the coating part and the opening part of the resist of the 2nd Embodiment. It is the schematic of the bonding substrate which formed the exposed part of the 2nd Embodiment. It is the schematic of the scribed bonding substrate of the 2nd Embodiment. It is the schematic of the bonding substrate which formed the coating part and the opening part of the resist of the comparative example. It is the schematic of the bonding substrate which exposed the intermediate composition layer in the scribe region of the comparative example. It is the schematic of the scribed bonding substrate of the comparative example. It is a figure which shows the relationship between the width of the exposed part and the area of a peeling part in an Example and a comparative example.

As described above, in the scribing braking process in which a substrate in which a light emitting layer and a transparent substrate (supporting substrate) are joined with an adhesive having a light absorption band in the ultraviolet region is scribed with a laser, the visible transparent adhesive absorbs laser energy. However, there has been a demand for the development of a method for manufacturing a light emitting element that is destroyed and suppressed from peeling from the joint.

As a result of diligent studies on the above problems, the present inventors have conducted scribing braking in a method for manufacturing a light emitting element in which a scribing braking step is performed by laser light in order to separate the light emitting element from a semiconductor substrate into a die shape. We have found that peeling from the joint can be suppressed by removing the adhesive in the scribing region in advance so that the adhesive layer does not exist, and completed the present invention.

That is, the present invention is a method for manufacturing a light emitting element.
(1) A step of forming a laminated structure including a light emitting layer portion in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially laminated by epitaxial growth on a starting substrate to produce a wafer for a light emitting element.
(2) Process of preparing the support substrate,
(3) A step of adhering the support substrate to the wafer for a light emitting element via an adhesive layer to prepare a bonded substrate.
(4) In the bonding substrate, a step of removing the starting substrate to expose the first semiconductor layer.
(5) A step of removing at least the first semiconductor layer and the active layer to form a removed portion in a part of the bonded substrate.
(6) The bonding substrate is formed by forming a first ohmic electrode on the surface of the first semiconductor layer and a second ohmic electrode on the surface of the removal portion, and (7) a scribing braking method using laser light. The process of separating the light emitting element into a die shape from
This is a method for manufacturing a light emitting element, which comprises the above and removes the adhesive layer in the scribing region in advance before scribing.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[Step (1)]
In the step (1), a laminated structure including a light emitting layer portion in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially laminated is formed on a starting substrate by epitaxial growth to prepare a wafer for a light emitting element. It is a process.

The wafer for a light emitting element produced in the step (1) includes a light emitting layer portion in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially laminated, and in addition to the light emitting layer portion, for example, a light emitting layer portion. An etch stop layer can be formed between the substrate and the starting substrate. Further, an intermediate composition layer, a GaP current diffusion layer, a first dielectric film and the like can be further formed on the light emitting layer portion. The light emitting element wafer may have a first adhesive layer for joining the support substrate and the light emitting element wafer, which will be described later, on the top of these layers. In the present invention, a light emitting device wafer can be manufactured by sequentially laminating these layers on a starting substrate. The starting substrate is not particularly limited, but a GaAs or Ge substrate can be used, and the first semiconductor layer, the active layer, and the second semiconductor layer can be AlGaInP-based.

[Step (2)]
Step (2) is a step of preparing a support substrate.

The support substrate prepared in the step (2) is composed of at least a visible transparent substrate. As the visible and transparent substrate, a sapphire substrate, a quartz substrate, or the like can be used. A dielectric film can be formed on the visible transparent substrate, and a second adhesive layer for joining the above-mentioned light emitting element wafer and the support substrate can be formed on the dielectric film.

Further, in the step (2), when the support substrate has a second adhesive layer, the adhesive layer in the scribe region is removed by processing the second adhesive layer into a desired pattern by a photolithography method or the like. be able to.

[Step (3)]
The step (3) is a step of adhering the support substrate to the wafer for the light emitting element via the adhesive layer to prepare a bonded substrate.

At this time, it is preferable that at least one of the support substrate and the light emitting element wafer has an adhesive layer. The adhesive that can be used here is not particularly limited, and examples thereof include BCB, epoxy resin, vinyl chloride resin, urethane resin, acrylic resin, and silicone.

[Step (4)]
The step (4) is a step of removing the starting substrate in the bonded substrate to expose the first semiconductor layer.

In the step (4), the starting substrate of the bonded substrate is removed by etching or the like. Further, if there is an etch stop layer, the etch stop layer can also be removed. By removing these layers, the first semiconductor layer is exposed.

[Step (5)]
The step (5) is a step of removing at least the first semiconductor layer and the active layer in a part of the bonded substrate to form a removed portion.

In the step (5), at least the first semiconductor layer and the active layer are cut out and removed to form a removing portion. Further, not only the first semiconductor layer and the active layer but also only the visible transparent substrate may be left, and all the layers may be cut out and removed to form a removing portion.

[Step (6)]
The step (6) is a step of forming the first ohmic electrode on the surface of the first semiconductor layer and the second ohmic electrode on the surface of the removing portion.

In step (6), for example, the electrode can be formed by the following method. First, a dielectric layer is formed on the surface of the bonded substrate on which the removed portion is formed in the step (5). Next, an opening (a portion where the first semiconductor layer and the removed portion are exposed) is formed in the dielectric layer by a photolithography method and a wet etching method. Then, at the opening, a first ohmic electrode is formed on the surface of the first semiconductor layer, and a second ohmic electrode is formed on the surface of the removing portion.

[Step (7)]
The step (7) is a step of separating the light emitting element from the bonded substrate into a die shape by using a scribe braking method using a laser beam.

In the step (7), first, in the scribe region, only the visible transparent substrate is left, and all the layers are removed. When the adhesive layer in the scribe region is not removed in the step (2), the adhesive layer can be removed at the same time here.

Next, as shown in FIG. 1, after removing the adhesive layer (first adhesive layer 10 and second adhesive layer 15) to form a scribe portion 28 by laser light in the scribe region where the visible transparent substrate 13 is exposed, the scribe portion 28 is formed. Braking is performed to separate the light emitting element into a die shape.

According to the method for manufacturing a light emitting element as described above, the adhesive is prevented from being broken and peeled off from the joint by preventing the adhesive layer from being present in the scribing region in the scribing / braking process. Can be done.

Further, the adhesive layer in the scribing region may be removed in advance at any time before scribing, but just before scribing in step (7) or when preparing the support substrate in step (2). For example, it can be done relatively easily. In addition, by setting the width of the region where the adhesive does not exist to 20 μm or more in the direction perpendicular to the scribe direction, it is not necessary to irradiate the adhesive layer with laser light, so that a dramatic peeling improvement effect can be obtained. can get.

Hereinafter, the method for manufacturing the light emitting device of the present invention will be described in more detail with reference to the drawings using the first embodiment and the second embodiment, but the present invention is not limited thereto. ..

[First Embodiment]
[Step (1)]
First, the first embodiment of the present invention will be described. As shown in FIG. 2, a wafer 1 for a light emitting element is placed on a GaAs substrate (starting substrate) 2 inclined by 15 degrees in the [001] direction by an organic metal vapor phase growth method (MOVPE) method (Al _x Ga). _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6), an etch stop layer 3 having a thickness of 0.1 to 1.0 μm, and a thickness of 0.5 to 0.5 to Thickness 0 consisting of 1.0 μm first conductive type first semiconductor layer 4, (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6) .1 to 1.0 μm active layer 5, (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1,0.4 ≦ y ≦ 0.6) with a thickness of 0.5 to second conductive type second semiconductor layer ₆ of 1.0 .mu.m, GaP having a _{Ga y in 1-y P (} 0.0 ≦ y ≦ 1.0) the intermediate composition layer thickness of 7,0.5~20μm consisting The current diffusion layers 8 can be sequentially laminated and formed.

The method for producing the wafer 1 for a light emitting element is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. Further, although not shown, a buffer layer may be provided between the GaAs substrate and the first semiconductor layer.

Further, as shown in FIG. 3, in the light emitting element wafer 1, a _{first dielectric film 9 made of SiO 2} or SiN _x is further formed on the GaP current diffusion layer 8 to have a thickness of, for example, 0.4 μm. The first adhesive layer 11 can be obtained by forming the first adhesive layer 10 on which the BCB adhesive is applied by spin coating. The thickness of the first adhesive layer varies depending on the viscosity of the BCB adhesive and the rotation speed at the time of spin coating. For example, the first adhesive layer 10 of about 0.5 μm can be formed at a rotation speed of 5000 rpm. In the present embodiment, the first bonding layer 11 is provided, but the wafer for a light emitting device used in the present invention has a structure that does not have the first bonding layer 11, a structure that does not have the first dielectric film 9, or the first adhesion. The structure may not have the layer 10.

[Step (2)]
As shown in FIG. 4, the support substrate 30 has a _{dielectric film 14 made of, for example, SiO 2} or SiN _x , formed on a visible transparent substrate 13 such as sapphire or quartz, and further adhered on the dielectric film 14 made of, for example, BCB resin. By applying the agent to form the second adhesive layer 15, it is possible to have the second bonding layer 12. The thickness of the second adhesive layer 15 varies depending on the viscosity of the BCB adhesive and the rotation speed at the time of spin coating, but in the present embodiment, the second adhesive layer 15 of about 0.5 μm can be formed at a rotation speed of 5000 rpm. When the first adhesive layer 10 is formed, the second adhesive layer 15 does not have to be provided, and when the second adhesive layer 15 is formed, the first adhesive layer 10 does not have to be provided, and both are formed. You may. Further, in addition to the BCB resin as the adhesive, the first adhesive layer 10 and the second adhesive layer 15 may be formed by other transparent and liquid members such as epoxy at room temperature.

[Step (3)]
Next, as shown in FIG. 5, the first adhesive layer 10 and the second adhesive layer 15 are opposed to each other, and the first adhesive layer 10 and the second adhesive layer 15 are formed by applying pressure and heat in a vacuum or reduced pressure atmosphere. The bonded bonding substrate 16 is formed. Adhesion can be achieved by crimping under conditions where the pressure is 6 N / cm ² or more and the temperature is 100 ° C. or more. In particular, it is preferable to join under the conditions of reaching 30 N / cm ^{2 and 300 ° C.}

[Step (4)]
Next, as shown in FIG. 6, the GaAs substrate 2 is removed from the bonding substrate 16 by chemical etching. The chemical etching solution is preferably an AlGaInP-based material and has etching selectivity, and is generally removed with an ammonia-containing etchant. After removing the GaAs substrate 2, the etch stop layer 3 is removed to form a bonded substrate 17 having an exposed surface (first surface) 18 of the first semiconductor layer. The etch stop layer 3 is removed with a mixed solution of hydrogen peroxide and an acid that etches the AlGaInP-based material.

[Step (5)]
Next, as shown in FIG. 7, a part of the exposed surface 18 of the first semiconductor layer is cut out from the bonding substrate 17 to form a removing portion (second surface) 19. In this aspect, the first semiconductor layer 4 and the active layer 5 are removed to expose the second semiconductor layer 6.

[Step (6)]
Next, the dielectric layer 21 is formed so as to cover the notched side surface 20 as shown in FIG. 8, and the opening 22 is provided. The dielectric layer 21 is preferably _{SiO 2} or SiN _x. A sol-gel method, a sputtering method, or a CVD method can be selected for forming the dielectric layer. The opening 22 can be provided by forming the dielectric layer 21, forming a mask portion by a photolithography method, and forming an exposed portion by a wet etching method using BHF.

Next, as shown in FIG. 9, the first ohmic electrode 23 is formed on a part of the exposed surface 18 of the first semiconductor layer, and the second ohmic electrode 24 is formed on a part of the removing portion 19.

[Step (7)]
Next, as shown in FIG. 10, a covering portion 25 and an opening portion 26 that cover the entire exposed surface 18 of the first semiconductor layer and a part of the removing portion 19 are formed by photolithography using a photoresist.

Next, as shown in FIG. 11, the opening 26 is removed by a dry etching method to expose a part 27 of the visible transparent substrate 13. The dry etching here will remove the adhesive layer in the scribe region. The AlGaInP layer is removed in an ICP apparatus in a mixed atmosphere of Cl-containing gas and Ar, and _{the dielectric layer of SiO 2} or SiN _x and the BCB layer are removed in a mixed atmosphere of F-containing gas and Ar. Can be done. The pressure atmosphere can be 0.5 Pa and the output can be plasma 300 W. The removal of the layer using Cl-containing gas and the removal of the layer using F-containing gas can be performed in separate chambers, or in the same chamber only by switching the gas without taking out the wafer from the vacuum atmosphere. It can also be carried out.

Next, as shown in FIG. 12, after the exposed portion 27 is formed, the covering portion 25 with the photoresist is removed. After removing the covering portion 25, the exposed portion 27 is irradiated with a laser to form the scribe portion 28. Then, a braking process is performed along the scribe portion 28 to make a die.

In the method of the first embodiment, since the adhesive layer does not exist in the laser irradiation region, it is relatively easy to produce a light emitting element in which the adhesive absorbs the laser energy, is destroyed, and is suppressed from peeling from the joint portion. Can be manufactured to.

[Second Embodiment]
[Step (1)]
Next, the second embodiment of the present invention will be described. As shown in FIG. 13, a wafer 1 for a light emitting element is placed on a GaAs substrate (starting substrate) 2 inclined by 15 degrees in the [001] direction by an organic metal vapor phase growth method (MOVPE) (Al _x Ga _{1- x} ) _{Etch stop layer 3 having a thickness of 0.1 to 1.0 μm composed of y} In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6), thickness 0.5 to 1. Thickness 0.1 consisting of 0 μm first conductive type first semiconductor layer 4, (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1, 0.4 ≦ y ≦ 0.6) A thickness of 0.5 to 1. consisting of an active layer 5 of ~ 1.0 μm and (Al _x Ga _1-x ) _y In _1-y P (0 ≦ x ≦ 1,0.4 ≦ y ≦ 0.6). the second semiconductor layer ₆ the second conductivity type made of _{0μm, Ga y in 1-y} P (0.0 ≦ y ≦ 1.0) GaP current having a thickness of the intermediate composition layer 7,0.5~20μm consisting The diffusion layers 8 can be sequentially laminated and formed.

The method for producing the wafer 1 for a light emitting element is not limited to MOVPE, and may be produced by a molecular beam epitaxy (MBE) method or a chemical beam epitaxy (CBE) method. Further, although not shown, a buffer layer may be provided between the GaAs substrate and the first semiconductor layer.

Further, as shown in FIG. 14, the light emitting element wafer 1 is formed on the GaP current diffusion layer 8 with a _{first dielectric film 9 made of, for example, SiO 2} or SiN _x having a thickness of about 0.4 μm. It can have one junction layer 11. In the present embodiment, the first bonding layer 11 is provided, but a structure that does not have the first bonding layer 11 may be used.

[Step (2)]
As shown in FIG. 15, the support substrate 30 has an adhesive layer 15 in which a dielectric film 14 made _{of SiO 2} or SiN _{x is formed on a visible transparent substrate 13 such as sapphire or quartz, and a BCB adhesive is further applied thereto.} By forming ´, it is possible to have the second bonding layer 12. The thickness of the adhesive layer 15'varies depending on the viscosity of the BCB adhesive and the rotation speed during spin coating. For example, a 0.5 μm adhesive layer 15'can be formed at a rotation speed of 5000 rpm.

Next, as shown in FIG. 16, the adhesive layer 15'is processed into a desired pattern 29 shape. At this stage, the adhesive layer in the scribe region will be removed. When a photosensitive material is selected from the BCB materials as the adhesive layer 15', a desired pattern 29 can be obtained by a photolithography method. Further, when a non-photosensitive material is selected from the BCB materials as the adhesive layer 15', the resist is coated so as to have a desired pattern by the photoresist method, and the desired pattern 29 is performed by an ICP apparatus having an F-containing gas atmosphere. Can be obtained. Here, the shape and size of the pattern 29 are restricted by the desired size of the light emitting element and the thickness of the adhesive layer 15'. The shape and size of the pattern 29 is less than or equal to the difference between the desired size of the light emitting element and the opening 26.

[Step (3)]
Next, as shown in FIG. 17, the first bonding layer 11 and the second bonding layer 12 are opposed to each other, and the first bonding layer 11 and the second bonding layer 12 are formed by applying pressure and heat in a vacuum or reduced pressure atmosphere. The bonded bonding substrate 16 is formed. Adhesion can be achieved by crimping under conditions where the pressure is 6 N / cm ² or more and the temperature is 100 ° C. or more. In particular, it is preferable to join under the conditions of reaching 30 N / cm ^{2 and 300 ° C.}

[Step (4)]
Next, as shown in FIG. 18, the GaAs substrate 2 is removed from the bonding substrate 16 by chemical etching. The chemical etching solution is preferably an AlGaInP-based material and has etching selectivity, and is generally removed with an ammonia-containing etchant. After removing the GaAs substrate 2, the etch stop layer 3 is removed to form the bonded substrate 17 having the exposed surface 18 of the first semiconductor layer. The etch stop layer 3 is removed with a mixed solution of hydrogen peroxide and an acid that etches the AlGaInP-based material.

[Step (5)]
Next, as shown in FIG. 19, the first semiconductor layer exposed surface 18 is left from the bonding substrate 17 within a range not exceeding the pattern 29, and a part of the first semiconductor layer exposed surface 18 is cut out to remove the first semiconductor layer 19. To form.

[Step (6)]
Next, the dielectric layer 21 is formed so as to cover the notched side surface 20 as shown in FIG. 20, and the opening 22 is provided. The dielectric layer 21 is preferably _{SiO 2} or SiN _x. A sol-gel method, a sputtering method, or a CVD method can be selected for forming the dielectric layer. The opening 22 can be provided by forming the dielectric layer 21, forming a mask portion by a photolithography method, and forming an exposed portion by a wet etching method using BHF.

Next, as shown in FIG. 21, the first ohmic electrode 23 is formed on a part of the exposed surface 18 of the first semiconductor layer, and the second ohmic electrode 24 is formed on a part of the removing portion 19.

[Step (7)]
Next, as shown in FIG. 22, a covering portion 25 and an opening portion 26 that cover the entire exposed surface 18 of the first semiconductor layer and a part of the removing portion 19 are formed by photolithography using a photoresist.

Next, as shown in FIG. 23, the opening 26 is removed by a dry etching method to expose a part 27 of the visible transparent substrate 13. The AlGaInP layer is removed in an ICP apparatus in a mixed atmosphere of Cl-containing gas and Ar, and _{the dielectric layer of SiO 2} or SiN _x and the BCB layer are removed in a mixed atmosphere of F-containing gas and Ar. Can be done. The pressure atmosphere can be 0.5 Pa and the output can be plasma 300 W. The removal of the layer using Cl _2- containing gas and the removal of the layer using F-containing gas can be performed in separate chambers, or in the same chamber only by switching the gas without taking out the wafer from the vacuum atmosphere. It can also be carried out.

Next, as shown in FIG. 24, after the exposed portion 27 is formed, the covering portion 25 with the photoresist is removed. After removing the covering portion 25, the exposed portion 27 is irradiated with a laser to form the scribe portion 28. Then, a braking process is performed along the scribe portion 28 to make a die.

Even in such a method of the second embodiment, since the adhesive layer does not exist in the laser irradiation region, the light emitting element in which the adhesive absorbs the laser energy, is destroyed, and is suppressed from peeling from the joint portion is relatively It can be easily manufactured.

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

[Example 1]
The light emitting element was manufactured based on the first embodiment of the method for manufacturing the light emitting device of the present invention as shown in FIGS. 2 to 12.

First, a wafer for a light emitting element was manufactured. A substrate (starting substrate) made of GaAs (001) was prepared as a starting substrate, and a double hetero layer (light emitting layer) as a functional layer was formed on this substrate by the MOVPE method. The light emitting layer was formed by sequentially laminating a lower clad layer (first semiconductor layer), an active layer, and an upper clad layer (second semiconductor layer).

_{The composition of (Al x} Ga _1-x ) _y In _1-y P (0.6 ≦ x ≦ 1.0, 0.4 ≦ y ≦ 0.6) is selected for the first semiconductor layer and the second semiconductor layer. In this embodiment, the n-type AlInP clad layer is 0.7 μm (doping concentration 3.0 × 10 ¹⁷ / cm ³ ) and the n-type Al _0.85 GaInP layer is 0.3 μm (doping) as the first semiconductor layer. It has a two-layer structure with a concentration of 1.0 × 10 ¹⁷ / cm ^3).

The active layer is selected from (Al _x Ga _1-x ) _y In _1-y P (0.15 ≦ x ≦ 0.8, 0.4 ≦ y ≦ 0.6), and the compositions x and y are determined according to the wavelength. changed. In this example, a multiple active layer was used as the active layer. The film thicknesses of the active layer and the barrier layer were changed according to the desired wavelength, and were adjusted according to the wavelength in the range of 4 to 12 nm, respectively.

As the second semiconductor layer, the p-type AlInP clad layer is 0.9 ^{μm (doping concentration 3.0 × 10 17} / cm ³ ), and the p-type Al _0.6 GaInP layer is 0.1 μm (doping concentration 1.0 × 10 ^17). It has a two-layer structure of ^{/ cm 3).}

A buffer layer made of GaInP was formed on the light emitting layer. _{Next, a dielectric film made of SiO 2} was formed on the buffer layer with a thickness of 0.4 μm, and a BCB adhesive was applied thereto by spin coating to form a first adhesive layer.

Next, the support substrate was prepared. _{First, a dielectric film made of SiO 2} was formed on sapphire, and a second adhesive layer coated with an adhesive made of BCB resin was formed on the dielectric film.

Next, in order to bond the light emitting wafer and the support substrate, the first adhesive layer and the second adhesive layer were bonded. Then, the GaAs substrate was removed with an ammonia-containing etchant. Subsequently, the etch stop layer was removed to expose the first semiconductor layer. Next, a part of the first semiconductor layer and the active layer was cut out to expose a part of the second semiconductor.

Next, a dielectric layer was formed so as to cover the notched side surface, and an opening was provided. The dielectric layer was SiO _2, and a film was formed by a P-CVD method using TEOS and O _2. The opening was provided by forming a dielectric layer, forming a mask portion by a photolithography method, and forming an exposed portion by a wet etching method using BHF.

Next, a first ohmic electrode and a second ohmic electrode were formed. Then, a part of the visible transparent substrate was exposed by a photolithography and a dry etching method. At this time, the width of the exposed portion (direction perpendicular to the scribe direction) was set to 5, 10, 15, 20, 25, 30 μm. The AlGaInP layer was removed in an ICP apparatus in a mixed atmosphere of Cl-containing gas and Ar, and _{the dielectric layer of SiO 2} and the BCB layer were removed in a mixed atmosphere of F-containing gas and Ar. The pressure atmosphere was 0.5 Pa and the output was plasma 300 W.

After forming the exposed portion, the photoresist was removed and a laser was irradiated to form a scribe portion. Braking was performed along the scribe section to make dice. FIG. 28 shows the relationship between the area where the joint portion due to the adhesive is peeled off and the width of the exposed portion (street portion width). It can be seen that the peeled area is reduced regardless of the width of the exposed portion as compared with the comparative example (width 0 μm) described later. Especially when the width is 20 μm or more, the peeling is dramatically improved.

[Example 2]
The light emitting element was manufactured based on the second embodiment of the method for manufacturing the light emitting device of the present invention as shown in FIGS. 13 to 24. A light emitting device was manufactured by the same method as in Example 1 except that the adhesive was processed into a desired pattern shape and then the transparent substrate was bonded. FIG. 28 shows the result of the peeling state. In Example 2, the same results as in Example 1 were obtained.

[Comparison example]
The light emitting element was manufactured by using the conventional method as shown in FIGS. 25 to 27. A light emitting device was manufactured by the same method as in Example 1 except that scribe was performed in the region where the adhesive was present. FIG. 28 shows the result of the peeling state. It can be seen that the peeled area is larger than that of Examples 1 and 2.

As described above, according to the method for manufacturing a light emitting element of the present invention, it is visible in the scribing / braking step of scribing a substrate in which a light emitting layer and a transparent substrate are joined with an adhesive having a light absorption band in the ultraviolet region with a laser. It has been clarified that the transparent adhesive can absorb the laser energy, break it, and prevent it from peeling off from the joint.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any object having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effect and effect is the present invention. Is included in the technical scope of.

1 ... Wafer for light emitting element, 2 ... GaAs substrate (starting substrate),
3 ... Etch stop layer, 4 ... First semiconductor layer, 5 ... Active layer, 6 ... Second semiconductor layer,
7 ... Intermediate composition layer, 8 ... Gap current diffusion layer, 9 ... First dielectric film,
10 ... 1st adhesive layer, 11 ... 1st bonding layer, 12 ... 2nd bonding layer,
13 ... Visible transparent substrate, 14 ... Dielectric film, 15 ... Second adhesive layer, 15'... Adhesive layer,
16 ... Bonded substrate, 17 ... Bonded substrate with the first semiconductor layer exposed,
18 ... First semiconductor layer exposed surface (first surface), 19 ... Removal part (second surface),
20 ... notched sides, 21 ... dielectric layer, 22 ... openings,
23 ... 1st ohmic electrode, 24 ... 2nd ohmic electrode, 25 ... covering part,
26 ... opening, 27 ... exposed, 28 ... scribe, 29 ... desired pattern,
30 ... Support substrate.

Claims (2)

It is a method of manufacturing a light emitting element.
(1) A step of forming a laminated structure including a light emitting layer portion in which a first semiconductor layer, an active layer, and a second semiconductor layer are sequentially laminated by epitaxial growth on a starting substrate to produce a wafer for a light emitting element.
(2) Process of preparing the support substrate,
(3) A step of adhering the support substrate to the wafer for a light emitting element via an adhesive layer to prepare a bonded substrate.
(4) In the bonding substrate, a step of removing the starting substrate to expose the first semiconductor layer.
(5) A step of removing at least the first semiconductor layer and the active layer to form a removed portion in a part of the bonded substrate.
(6) The bonding substrate is formed by forming a first ohmic electrode on the surface of the first semiconductor layer and a second ohmic electrode on the surface of the removal portion, and (7) a scribing braking method using laser light. The process of separating the light emitting element into a die shape from
A method for manufacturing a light emitting element, which comprises the above and removes the adhesive layer in the scribing region in advance before scribing.
In the step (7), the adhesive layer in the scribe region is removed or the adhesive layer in the scribe region is removed by photolithography and dry etching before scribe.
The feature of the step (2) is that the support substrate has an adhesive layer, and the adhesive layer is removed so that the adhesive layer does not exist in the scribe region. A method for manufacturing a light emitting element. The method for manufacturing a light emitting element according to claim 1, wherein the width of the region where the adhesive layer does not exist is 20 μm or more in a direction perpendicular to the scribe direction.

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