JP6387656B2 - Method for manufacturing light emitting device - Google Patents

Description

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

Conventionally, a semiconductor layer is stacked on a semiconductor growth substrate made of sapphire, which is different from the semiconductor layer, and a light emitting element is manufactured using these stacked bodies.
In recent years, with the use of light emitting elements in various forms, further downsizing and thinning have been demanded while ensuring necessary characteristics such as luminance and reliability.
Therefore, a laser lift-off method may be used as a method for removing the substrate (for example, Patent Document 1).

The laser lift method irradiates a laser beam from the substrate side, absorbs the energy of the laser beam in the semiconductor layer near the interface between the substrate and the semiconductor layer, decomposes, and occurs between the substrate and the semiconductor layer, etc. caused by the decomposition. This is a method of separating the above-mentioned foreign substrate from the semiconductor layer using a minute gap.
In order to execute such a laser lift-off method, usually, a semiconductor laminate and an electrode and / or protective film formed thereon are integrally supported or fixed by a resin or the like, and then mounted on a substrate. A method of irradiating with laser light is employed.

JP 2011-71272 A

In general, when a light emitting device is manufactured by forming a semiconductor laminate on a substrate, in order to divide each chip after separating the substrate described above, division lines are set in the vertical and horizontal directions before the substrate is separated. The semiconductor stacked body in the peripheral region along the line is partially or entirely removed in the thickness direction.
And since resin is used for support or fixation of the above-mentioned semiconductor laminated body etc., the division | segmentation for every chip | tip is performed using mechanical cutting tools, such as a diamond blade.

  However, when removing only a part of the semiconductor laminate around the line in the thickness direction, cracks occur in the remaining semiconductor laminate due to the division by the mechanical cutting tool, and the light emitting element is configured due to the crack. In some cases, cracks may also occur in the semiconductor laminate in the region to be processed.

  On the other hand, if all of the semiconductor stack in the thickness direction around the line is removed, a protective film or resin is present on the upper surface of the substrate. Therefore, when performing the laser lift-off method, the laser beam does not react to this part. It will be. Therefore, in this part, there is a problem that separation of the substrate becomes difficult because the semiconductor layer is not decomposed and no gap is generated, and the substrate is in a state of being bonded to the protective film or the resin. Moreover, since resin is arrange | positioned to the peripheral part along a division | segmentation scheduled line in almost all the thickness directions, there also exists a problem that the burr | flash of resin etc. with a machine cutting tool tends to generate | occur | produce. When such a burr | flash generate | occur | produces, there exists a possibility that a light distribution may be affected by a burr | blocking the light which generate | occur | produced in the semiconductor laminated body.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing a light-emitting element that can easily perform a laser lift-off method while preventing the occurrence of burrs.

The present invention includes the following inventions.
Preparing a semiconductor stack having a first semiconductor layer and a plurality of second semiconductor layers disposed on a partial region of the first semiconductor layer on a first main surface of the substrate;
A spaced-apart semiconductor sandwiched between the first semiconductor layers between the second semiconductor layers adjacent to each other by forming groove portions reaching the first main surface of the substrate so as to surround respective peripheral portions of the second semiconductor layers. Separating the layer from the semiconductor stack;
Forming a first protective film that integrally covers the groove and the separated semiconductor layer;
A support member made of resin is provided on the surface of the first protective film opposite to the substrate,
Irradiating a laser beam from the second main surface side opposite to the first main surface of the substrate to separate the substrate from the semiconductor stacked body and the separated semiconductor layer,
A method of manufacturing a light emitting device including cutting the separated semiconductor layer into a plurality of light emitting devices using a blade from the support member side, and a first semiconductor layer on a first main surface of a substrate And a semiconductor stacked body having a plurality of second semiconductor layers disposed on a partial region of the first semiconductor layer,
A plurality of groove portions reaching the first main surface of the substrate are formed in the first semiconductor layer between the adjacent second semiconductor layers so as to surround respective peripheral portions of the second semiconductor layer and sandwiched between the groove portions. , Forming a plurality of spaced semiconductor layers spaced from the semiconductor laminate,
Forming a first protective film that integrally covers the plurality of grooves and the plurality of spaced-apart semiconductor layers;
A support member made of resin is provided on the surface of the first protective film opposite to the substrate,
Irradiating a laser beam from the second main surface side opposite to the first main surface of the substrate to separate the substrate from the semiconductor stacked body and the separated semiconductor layer,
A method for manufacturing a light-emitting element, comprising cutting one of the plurality of spaced-apart semiconductor layers using a blade from the support member side into individual light-emitting elements.

  According to the present invention, by performing the laser lift method, it is possible to easily manufacture a light-emitting element that is small / thinned and has high reliability.

It is a schematic plan view of the light emitting element manufactured in Embodiment 1 of the present invention. It is a schematic sectional drawing in the A-A 'line of FIG. 1A. It is a schematic sectional drawing in the B-B 'line of FIG. 1A. It is a schematic sectional drawing which shows the light emitting element of 1 unit in the B-B 'line | wire of FIG. 1A. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 1 of this invention. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 1 of this invention. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 1 of this invention. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 2 of this invention. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 2 of this invention. It is a schematic sectional process drawing which shows the manufacturing method of the light emitting element of Embodiment 2 of this invention.

Hereinafter, embodiments for carrying out a method for manufacturing a light emitting device according to the present invention will be described in detail with reference to the drawings. The size, thickness, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name or reference sign indicates the same or the same member in principle, and the detailed description is omitted as appropriate.
In the light emitting element and its member, the first main surface and the corresponding surface may be referred to as “upper surface”, and the second main surface and the corresponding surface may be referred to as “lower surface”.

The method for manufacturing a light emitting device of the present invention generally includes:
(A) preparing a semiconductor laminate formed on the first main surface of the substrate;
(B) forming a separated semiconductor layer;
(C) forming a first protective film;
(D) forming a support member;
(E) separating the substrate from the semiconductor stack;
(F) cutting the separated semiconductor layer.
Or
(A) preparing a semiconductor laminate formed on the first main surface of the substrate;
(B ′) forming a plurality of spaced semiconductor layers;
(C ′) forming a first protective film;
(D) forming a support member;
(E) separating the substrate from the semiconductor stack;
(F ′) includes a step of cutting any one of the plurality of separated semiconductor layers.

Further, during or after these steps, (G) a light reflective electrode is further formed,
(H) forming a second electrode electrically connected to the second semiconductor layer;
(I) forming a first electrode electrically connected to the first semiconductor layer;
(J) forming a second protective film;
(K) forming a second external electrode;
(L) forming a first external electrode;
(M) You may perform arbitrarily the process etc. which form a translucent member.

(A) Preparation of semiconductor stacked body A semiconductor stacked body formed on the first main surface of the substrate is prepared.
The semiconductor laminate is an aggregate in which a plurality of semiconductor layer laminates that can constitute one unit of light emitting element are integrally laminated. Especially, it is preferable that a semiconductor laminated body has a 1st semiconductor layer and several 2nd semiconductor layers arrange | positioned on the one part area | region of this 1st semiconductor layer. Especially, a 1st semiconductor layer, It is preferable that the light emitting layer and the second semiconductor layer are stacked in this order on the upper surface of the substrate. Here, the first may be n-type, and the second may be p-type, or vice versa.

The types and materials of the first semiconductor layer, the light emitting layer, and the second semiconductor layer are not particularly limited, and examples thereof include In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y <1). A gallium nitride based semiconductor material is preferably used. All of the first semiconductor layer, the light emitting layer, and the second semiconductor layer may be a single layer, or may include a multilayer structure of two or more layers or a superlattice.
The thicknesses of the first semiconductor layer, the light emitting layer, the second semiconductor layer, and the semiconductor stacked body are not particularly limited, and can be appropriately adjusted depending on intended characteristics, materials used, and the like.

The semiconductor laminate is usually laminated on a substrate. The material of the substrate may be any material that can transmit laser light used in the laser lift-off method when the substrate is separated from the semiconductor stacked body as will be described later. For example, sapphire (Al ₂ O ₃ ), spinel (MgA1) ₂ O ₄ ), silicon carbide (SiC), ZnS, ZnO, GaAs, and the like.

  As will be described later, the semiconductor stacked body is formed in order to form the first electrode and the second electrode on the first semiconductor layer and the second semiconductor layer, respectively, or to divide each unit of light emitting elements. 2 It has the area | region which a semiconductor layer and a light emitting layer do not arrange | position. In this region, the first semiconductor layer is exposed. In this region, a part of the first semiconductor layer in the thickness direction may be removed. Hereinafter, the region where the first semiconductor layer is exposed may be referred to as an exposed region.

  The exposed region is preferably arranged such that the second semiconductor layer forms a quadrangle in plan view, for example. However, the angle of the angle is allowed to fluctuate by about ± 5 degrees due to processing accuracy and the like. In this case, it is more preferable to form the second semiconductor layer so as to be arranged in the matrix direction on the upper surface of the substrate. For this reason, the exposed region of the first semiconductor layer is preferably formed in a lattice shape on the upper surface of the substrate.

(Formation of light reflective electrode)
A light reflective electrode is preferably formed on the top surface of the first semiconductor layer and / or the second semiconductor layer. Here, the light reflectivity means a property of reflecting light emitted from the light emitting layer by 80%, 85%, 90%, 95% or more.

  The light reflective electrode is not particularly limited as long as it is a material that can be electrically connected to the semiconductor layer. For example, nickel (Ni), titanium (Ti), tungsten (W), platinum (Pt), rhodium (Rh), palladium (Pd), vanadium (V), chromium (Cr), niobium (Nb), zinc (Zn), tantalum (Ta), molybdenum (Mn), hafnium (Hf), aluminum (Al), silver Examples thereof include metals such as (Ag) and copper (Cu) or alloys containing them, such as alloys of Al and Cu (AC), alloys of Al, Si and Cu (ASC), and the like. These electrode materials may be a single layer or a laminated structure.

  When the light reflective electrode has a laminated structure, each layer may have the same shape, and at least one upper layer preferably covers at least one lower layer. Covering here means covering the entire exposed surface such as the top and side surfaces. In particular, when silver or a silver alloy is used in the lower layer, it is preferable to cover the entire lower layer with silver or a silver alloy in the upper layer. This can effectively prevent silver migration.

The light reflective electrode is formed by a known method such as a vacuum deposition method, an ion plating method, an ion vapor deposition (IVD) method, a sputtering method, a plasma deposition method, or a chemical vapor deposition (CVD) method. be able to. Further, when patterning the light reflective electrode into a desired shape, a known method such as photolithography and dry etching or wet etching, a lift-off method, or the like can be used.
The thickness of the light-reflecting electrode is not particularly limited and can be appropriately adjusted depending on intended characteristics and the like.

  The size and shape of the light-reflecting electrode are not particularly limited, and are usually the same as the upper surface of each semiconductor layer of the semiconductor stack in order to uniformly supply current to the entire surface of the semiconductor layer. It is preferable that the size is slightly smaller than that, and the shape is similar to or similar to the top surface of each semiconductor layer of the semiconductor stack.

  The light reflective electrode may be formed only on one of the first semiconductor layer and the second semiconductor layer in the semiconductor stacked body, but is formed on the second semiconductor layer having a larger exposed area in order to extract light efficiently. It is preferable to do.

(B) and (B ′) Formation of Separated Semiconductor Layer A groove portion reaching the upper surface of the substrate is formed in the first semiconductor layer between the adjacent second semiconductor layers to form a separated semiconductor layer. The groove is preferably formed so as to surround at least a part, preferably all of the peripheral part of each second semiconductor layer. By forming such a groove portion, a separated semiconductor layer that is sandwiched between the groove portions and separated from the semiconductor stacked body is formed. By providing the separated semiconductor layer around the adjacent second semiconductor layer, that is, around the planned division line, when the substrate is peeled from the semiconductor laminate by the laser lift-off method, the separation of the separated semiconductor layer and the gap between the substrate and the substrate are separated. Occurrence occurs. Therefore, the substrate can be easily peeled as compared with the case where all of the semiconductor stacked body around the planned division line is removed.
Here, the adjacent second semiconductor layer means that the regions of the second semiconductor layer for constituting one unit of light emitting element are adjacent to each other. It also includes a second semiconductor layer that is adjacent and remains connected to form the device. Therefore, as long as the groove reaches the substrate, the groove may extend in the entire thickness direction of the semiconductor stacked body in which the first semiconductor layer, the light emitting layer, and the second semiconductor layer are stacked. In these cases, the spaced apart semiconductor layer does not directly contribute to light emission, and therefore may include all of the first semiconductor layer, the light emitting layer, and the second semiconductor layer, or the first semiconductor layer and the light emitting layer. May be provided, or only the first semiconductor layer may be provided.

In particular, in the previous step, an exposed region of the first semiconductor layer to be divided for each light emitting element is formed, and thereby, between the adjacent second semiconductor layers spaced apart from each other, that is, in the exposed region. It is preferable to form a groove. In this case, the separated semiconductor layer includes only the first semiconductor layer. As a result, the groove can be easily and accurately formed.
The depth of the first groove may extend into the substrate as long as it reaches the upper surface of the substrate.
Such a groove can usually be formed by photolithography and etching processes. Moreover, you may utilize well-known methods, such as a laser ablation method.
Two or more groove portions may be disposed between adjacent second semiconductor layers so as to surround each peripheral portion of the second semiconductor layer.
The width of the groove is not limited as long as the island-shaped semiconductor layer sandwiched between the two grooves can be separated from the semiconductor stacked body constituting the light emitting element. Specifically, it is larger than 0 μm and not more than about 35 μm, and more preferably 10 μm or more and 15 μm or less. As a result, the area where the substrate is in contact with the protective film can be reduced as much as possible, so that the substrate can be easily peeled off by the laser lift-off method.

The spaced-apart semiconductor layer should just be arrange | positioned adjacent to the semiconductor laminated body for comprising 1 unit of light emitting elements, ie, the both sides (one of a row direction and a column direction) of this semiconductor laminated body, It is preferable that it is arrange | positioned at the other both sides (the other of row direction and column direction).
The width and length of the island-shaped semiconductor layer are not particularly limited, and can be appropriately adjusted depending on the arrangement of two adjacent groove portions.

  Further, a plurality of groove portions may be formed between adjacent second semiconductor layers, and a plurality of spaced semiconductor layers may be provided. For example, a plurality of spaced-apart semiconductor layers can be formed by forming further groove portions so as to surround the outer sides of the groove portions surrounding the respective peripheral edge portions of the second semiconductor layer.

(C) and (C ′) Formation of First Protective Film A first protective film that integrally covers the groove formed in the previous step and the separated semiconductor layer is formed.
When the groove and the separated semiconductor layer are formed in the previous step, the first protective film is embedded in all of the groove and the groove, and covers the separated semiconductor layer and at least a part of the separated semiconductor layer. Are preferably formed integrally.
It is preferable that a part of the first protective film covers a part of the first semiconductor layer exposed in the semiconductor stacked body.

Simultaneously with the formation of the first protective film, it is preferable to form a second protective film that covers the second semiconductor layer from the first semiconductor layer.
Here, simultaneous means that the material of the protective film is applied to the entire surface of the substrate, for example, vacuum deposition, ion plating, ion vapor deposition (IVD), etc., sputtering, ECR sputtering, plasma deposition. , Chemical vapor deposition (CVD) method, ECR-CVD method, ECR-plasma CVD method, EB method, ALD method, etc., and then, for example, photolithography and dry etching or wet etching It means that the first protective film and the second protective film are separated and patterned by a known method such as a process.

  The first protective film and the second protective film are preferably separated from each other on the semiconductor stacked body constituting the light emitting element, preferably at the outer peripheral portion of the semiconductor stacked body. In other words, it is preferable that both the end portion of the first protective film and the end portion of the second protective film are arranged apart from each other at the outer peripheral portion of the semiconductor stacked body constituting one light emitting element. In particular, the second protective film is preferably separated from the first protective film on the first semiconductor layer. Since the second protective film is separated from the first protective film, the first semiconductor layer and the first electrode are electrically connected in a portion where the second protective film and the second protective film are separated from each other. Can be connected.

The first protective film and the second protective film are each a single layer or a stacked structure made of an oxide, nitride, or oxynitride containing at least one element selected from the group consisting of Si, Ti, Zr, Nb, Ta, and Al. Can be formed. For example, it can be formed of at least one selected from the group consisting of silicon oxide, niobium oxide, titanium oxide, aluminum oxide, zirconium oxide, and tantalum oxide. In particular, the first protective film preferably has a two-layer structure such as Nb ₂ O ₅ / SiO ₂ , TiO ₂ / SiO ₂ or the like. This is because Nb ₂ O ₅ and TiO ₂ easily react to the laser beam used by the laser lift-off method, and the substrate is more easily separated from the semiconductor stacked body.

  The first protective film and the second protective film may be formed as a DBR (distributed Bragg reflector) type structure composed of a multilayer structure film in which two or more kinds of dielectrics are laminated. A multilayer structure film in which a plurality of the above dielectric layers and a metal reflective layer are laminated may be used. As a metal reflective layer, it can form as a layer of a single layer or a laminated structure with a highly reflective metal or alloy, such as Al and Ag. When Al is used alone, a high-power light-emitting element can be obtained. Examples of the Al alloy include alloys with Cu, Ag, Pt, Si, etc. containing Al as a main component (containing 50 atom% or more). In particular, when an alloy of Al and Cu (AC) or an alloy of Al, Si and Cu (ASC) is used, Al migration can be suppressed, and a highly reliable light-emitting element can be obtained.

When the metal reflective layer is formed of Al, Ag, or the like, it is preferable to laminate an insulating or conductive material having an effect of preventing corrosion of Al, Ag, or the like thereon. Examples of such a laminated structure include a two-layer structure such as Al alloy / Ti, and a three-layer structure such as Al alloy / SiO ₂ / Ti. The thickness of the metal reflective layer is not particularly limited, and examples thereof include about 100 nm to 5 μm.

  The thickness of a 1st protective film and a 2nd protective film is not specifically limited, For example, about 0.1 micrometer-20 micrometers are preferable, and about 0.5 micrometer-10 micrometers are more preferable.

The second protective film preferably has an opening.
The opening is a through-hole penetrating the second protective film in the thickness direction, and is preferably disposed on a partial region of the second semiconductor layer. Although this opening may be formed in a place other than on the light reflective electrode, it is more preferable that the opening is disposed on the region of the second semiconductor layer and on the above-described light reflective electrode. Thereby, the 2nd electrode mentioned later can be connected with a light reflective electrode.
As for the shape of the opening, for example, the planar shape can be a circle, an ellipse, a polygon, and the like, and the size, number, layout, and the like can be set as appropriate. For example, it can be arranged regularly or randomly in only one, in multiple instances and / or in multiple rows, or in multiple columns and multiple rows.

(Formation of first electrode and second electrode)
The first electrode and the second electrode are formed on the first semiconductor layer and the second semiconductor layer so as to be electrically connected to each other. When the light reflective electrode is formed in the previous step, the light reflective electrode may be formed so as to be electrically connected to the first semiconductor layer and the second semiconductor layer via the light reflective electrode.
The first electrode and the second electrode are not particularly limited. For example, the first electrode and the second electrode are appropriately selected from the materials exemplified as the light reflective electrode so that light from the semiconductor stacked body (that is, the light emitting layer) can be efficiently extracted. can do. In addition, a conductive oxide containing at least one element selected from the group consisting of zinc, indium, tin, gallium and magnesium (for example, ITO, ZnO, IZO, GZO, In ₂ O ₃ and SnO ₂ ), etc. May be used. These electrode materials may be a single layer or a laminated structure.

The first electrode and the second electrode can be formed by a method similar to the method exemplified for the light reflective electrode described above.
The thickness, size, and shape of the first electrode and the second electrode can be appropriately adjusted depending on the intended characteristics.
In particular, the second electrode is preferably formed only on the second semiconductor layer, particularly only on the light reflective electrode. In other words, as described above, the second protective film has an opening that exposes a part of the second semiconductor layer disposed on the second semiconductor layer, in particular, the light reflective electrode. Therefore, the second electrode connected to the light reflective electrode through this opening is formed.
The first electrode is preferably formed on the first semiconductor layer, particularly on the first semiconductor layer where the first protective film and the second protective film are separated from each other. Moreover, you may form so that it may arrange | position on a 1st protective film and / or a 2nd protective film. Furthermore, it is more preferable to arrange | position via a 2nd protective film so that it may arrange | position also on a 2nd semiconductor layer.

(Formation of first external electrode and second external electrode layer)
The first external electrode and the second external electrode refer to electrodes for connecting to terminals or electrodes other than the light emitting element for supplying electric power from the outside, and are in a pad shape, a wire shape, a bump shape, and a combination thereof. Various forms of electrodes.

These first external electrode and second external electrode are preferably formed simultaneously.
Here, the term “simultaneously” means that the wires constituting the first external electrode and the second external electrode are sequentially wire-bonded to the first electrode and the second electrode, and the material of the external electrode is formed on the entire surface of the substrate, A patterning method by a known method, for example, a resist layer having an opening in a region for forming the first external electrode and / or the second external electrode is formed in advance, and the material of the external electrode is formed on the entire surface of the substrate. And a method of patterning the external electrode material by using a lift-off method.

The first external electrode and the second external electrode can be appropriately selected from the materials exemplified as the first electrode and the second electrode. Conductive wires using metals such as gold, copper, platinum, and aluminum having a diameter of about 10 to 70 μm and alloys thereof, for example, conductive oxides such as ITO, metals of platinum group elements, Ni / Au, Ti / Rh / Ti, Ti / Pt / Au, Ti / Rh / Au, Ti / Ni / Au, Co / Au, Rh / Ir, Pt / Pd, and the like. When using a wire, it is preferable to perform bonding so as to form a loop between the first electrodes, between the second electrodes, or between the first electrode and the second electrode.
The thicknesses of the first external electrode and the second external electrode are not particularly limited, and can be appropriately adjusted according to intended characteristics. When the first external electrode and the second external electrode include a wire, the height of the wire is not particularly limited and can be appropriately adjusted depending on intended characteristics and the like.

(D) formation of a support member;
A support member is formed on the first protective film, that is, on the side of the first protective film opposite to the substrate. The support member is made of resin. Examples of the resin that can be used include resins such as polycarbonate resin, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), ABS resin, epoxy resin, phenol resin, acrylic resin, and PBT resin. These resins may contain additives such as a colorant, a light shielding material, and a light diffusing material. Examples of these additives include TiO ₂ , SiO ₂ , Cr ₂ O ₃ , MnO ₂ , Fe ₂ O ₃ , and carbon black.

The supporting member made of such a resin can be formed by various methods such as a molding method, a potting method, and a printing method.
The support member is preferably formed so as to expose the first external electrode and the second external electrode. In this case, after the support member is formed by the above-described method, the surface of the support member may be polished or cut to perform processing for exposing the upper surfaces of the first external electrode and the second external electrode. You may employ | adopt the method of apply | coating a support member etc., with the electrode and the 2nd external electrode exposed.

  In particular, when a wire is used for a part of the first external electrode and the second external electrode, it is preferable to bond the wire to the first electrode and the second electrode and then expose the surface of the wire to form the support member. Moreover, it is preferable to arrange | position an electrode pattern on a supporting member so that the single layer or laminated structure film | membrane of the electrode material mentioned above may be connected to the exposed wire. Accordingly, the first external electrode and the second external electrode may be formed by these wires and electrode patterns, respectively. Each of the electrode patterns is preferably disposed in a region where a semiconductor layer stack that can constitute one unit of light emitting element is disposed.

  The thickness of the support member is not particularly limited, and is preferably set to a thickness that can completely cover at least the semiconductor laminate and the first and second electrodes.

(E) Separation of Substrate Laser light (for example, KrF excimer laser, YAG laser) is irradiated from the second main surface (lower surface) side of the substrate to separate the substrate from the semiconductor stacked body and the separated semiconductor layer. As a method for separating the substrate, a known laser lift-off method can be used. For example, a method described in Japanese Patent Application Laid-Open No. 2007-300134, a laser lift-off device described in Japanese Patent Application Laid-Open No. 2012-15150, a commercially available laser lift-off device (UX4-LEDs LLO150, manufactured by Ushio Inc.) and the like can be used.

(Formation of translucent member)
After separating the substrate from the semiconductor laminate, it is preferable to form a translucent member on the surface where the substrate was present.
The light transmissive member preferably transmits 80% or more of light emitted from the light emitting layer, and more preferably transmits 90% or more. Translucent members include, for example, silicone resin compositions, modified silicone resin compositions, epoxy resin compositions, modified epoxy resin compositions, acrylic resin compositions, silicone resins, epoxy resins, urea resins, fluororesins, and the like. It can be formed of a resin such as a hybrid resin containing at least one resin. The translucent member may contain a phosphor, a light scattering material, an inorganic filler, and the like known in the art.

As the phosphor, those known in the art can be used. For example, when a gallium nitride-based light emitting device that emits blue light is used as the light emitting device, a YAG system that absorbs blue light to emit yellow to green light, a LAG system, a SiAlON system that emits green light (β sialon), a SCASN that emits red light, CASN type phosphors may be used alone or in combination.
The translucent member may be a single layer or a laminated structure, and may be a combination of two or more of phosphors, light scattering materials, inorganic fillers, and the like.

  The thickness of the translucent member can be appropriately adjusted depending on the material used, the amount of the phosphor, the light scattering material, the inorganic filler, and the like, the intended characteristics, and the like.

(F) and (F ′) Cutting of semiconductor stacked body From the support member side, the separated semiconductor layer is cut using a blade. Thereby, a plurality of light emitting elements can be separated.
Any blade conventionally used in the art can be used. The use conditions for cutting with a blade can also be adjusted as appropriate.

  When a plurality of separated semiconductor layers are formed, any of the separated semiconductor layers may be cut or all of them may be cut. Thereby, it can be separated into a plurality of light emitting elements.

Through such a series of steps, the first semiconductor layer can be disposed in a peripheral region (exposed region) along a planned division line formed to divide the semiconductor stacked body into units of light emitting elements. Therefore, when the laser lift-off method is performed, the laser beam does not pass through this portion. Therefore, in this portion, the semiconductor layer is sufficiently decomposed and the gap is generated, and the substrate can be reliably separated.
Even when dividing with a mechanical cutting tool, it is possible to effectively prevent cracks from occurring in the semiconductor laminate in the region constituting the light-emitting element by cutting the separated semiconductor layer separated from the semiconductor laminate. can do. As a result, reliability as a light emitting element can be ensured.
Furthermore, in the peripheral region along the planned dividing line, the resin is not disposed in all of the thickness direction, but a separated semiconductor layer exists on the surface on the side where the substrate is separated. Therefore, resin burrs due to the machine cutting tool can be effectively prevented.

Embodiments of a method for producing a light-emitting device according to the present invention will be specifically described below with reference to the drawings. However, the form shown below is the illustration for materializing the technical idea of this invention, Comprising: This invention is not limited to the following.
<Embodiment 1>
As shown in FIGS. 1A to 1D, the light emitting device 10 manufactured in this embodiment mainly includes a semiconductor stacked body 11, a separated semiconductor layer 12, a light reflective electrode 13, and a first protective film 14. A second protective film 15, a first electrode 16, a second electrode 17, a support member 18, a first external electrode 19, a second external electrode 20, and a translucent member 21, The plan view is formed in a substantially rectangular shape.
1A shows a 4-unit light-emitting element 10, FIG. 1B shows only the electrode structure of the 1-unit light-emitting element in the cross-sectional view taken along the line AA ′ of FIG. 1A, and FIG. It is an enlarged view which shows in detail only the electrode structure of the light emitting element of 1 unit in B 'line sectional drawing.

As shown in FIG. 1D, the semiconductor stacked body 11 includes a first semiconductor layer 3 (for example, n layer), a light emitting layer 29, and a second semiconductor layer 4 (for example, p layer) stacked in this order. The first semiconductor layer 3 is exposed from the second semiconductor layer 4 and the light emitting layer 29 at the outer peripheral portion of the semiconductor stacked body 11.
The separated semiconductor layer 12 is composed of a first semiconductor layer and is separated by the semiconductor stacked body 11 and the groove 22. That is, the separated semiconductor layer 12 is disposed between the groove portions 22 so as to surround each peripheral edge portion of the second semiconductor layer. The groove portion 22 is disposed so as to surround the entire outer periphery of the semiconductor stacked body 11 and has a width of about 10 μm to 15 μm.

  A light reflective electrode 13 is formed on substantially the entire top surface of the second semiconductor layer 4. As shown in FIG. 1D, the light reflective electrode 13 includes an Ag (film thickness of about 0.1 μm) film 13 a, a Ni (film thickness of about 0.3 μm) film 13 b, and Ti (film thickness of 0) from the second semiconductor layer 4 side. .1 μm) film 13 c and Ru (film thickness of about 0.1 μm) film 13 d are laminated in the same shape, and AlCu (film thickness of about 2 μm) film 13 e is laminated so as to cover all of the upper surface and side surfaces of these laminated films. Being done.

The first protective film 14 integrally covers all of the groove 22 and the separated semiconductor layer 13 and part of the semiconductor stacked body 11. The first protective film 14 is made of, for example, SiO ₂ (film thickness of about 1 μm).
The second protective film 15 is disposed from the first semiconductor layer 3 to the second semiconductor layer so as to be separated from the first protective film 14 by about 10 μm on the first semiconductor layer 3. The second protective film 15 has an opening 23 in a partial region on the second semiconductor layer 4.

The first electrode 16 is electrically connected to the first semiconductor layer 3 where the first protective film 14 and the second protective film 15 are exposed to be separated from each other. The first electrode 16 is disposed over the separated semiconductor layer 12, the groove 22, the first semiconductor layer 3, and the second semiconductor layer 4.
The second electrode 17 is formed in the opening 23 on a partial region of the second protective film 15 on the second semiconductor layer, and is electrically connected to the second semiconductor layer 4.
As shown in FIG. 1D, the first electrode 16 includes an ASC (film thickness of about 0.3 μm) film 16a, a Ti (film thickness of about 0.3 μm) film 16b, and a Pt (film thickness of about 0.1 μm) from the semiconductor layer side. ) A film 16c and an Au (film thickness of about 0.5 μm) film 16d are laminated. The second electrode 17 also has the same laminated structure as these.

  The support member 18 is formed of an epoxy resin containing about 1% by weight of carbon black. The support member 18 includes the semiconductor stacked body 11, the separated semiconductor layer 12, the groove 22, the first electrode 16 and the second electrode 17 on the first protective film 14 and the second protective film 15, and the second protective film 15. A part of the opening 23 formed in the first part and a part of the first external electrode 19 and the second external electrode 20 are integrally covered. Further, the upper surface thereof is relatively flat, and other parts of the first external electrode 19 and the second external electrode 20 are placed thereon.

As shown in FIG. 1D, the first external electrode 19 is connected to the wire 19a bonded to the first electrode 16 disposed above the second semiconductor layer, and to the end of the wire 19a. And an electrode pattern disposed on the substrate.
The second external electrode 20 is connected to the wire 20a bonded to the second electrode 17 connected to the second semiconductor layer in the opening 23 formed in the second protective film 15, and to the end of the wire 20a. And an electrode pattern disposed on the upper surface of the support member 18.

  The wires 19a and 20a are made of a gold wire having a diameter of about 35 μm. The electrode pattern is formed from a stacked structure of Ni (film thickness of about 0.2 μm) films 19b and 20b and Au (film thickness of about 1 μm) films 19c and 20c from the support member 18 side. The electrode patterns constituting the first external electrode 19 and the second external electrode 20 have the same plane area, for example, each having a plane area of about 20% of the plane area of the light emitting element.

  The translucent member 21 is disposed on the surface of the semiconductor stacked body 11 opposite to the support member 18. The translucent member 21 is formed with a thickness of about 20 μm by a silicone resin containing about 70% by weight of a phosphor.

The light emitting element having such a configuration can be manufactured by the following method.
As shown in FIG. 2A (a), on a substrate 2 made of a sapphire wafer having an uneven surface, for example, In _x Al _y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y <1). The semiconductor stacked body 11 is formed by stacking the first semiconductor layer 3, the light emitting layer 29, and the second semiconductor layer 4.
Next, a laminated film made of Ag, Ni, Ti, and Ru is formed on the second semiconductor layer of the semiconductor laminated body 11 and patterned into a predetermined shape by photolithography and etching processes. Subsequently, a single layer film made of AlCu is formed on the patterned laminated film and patterned to form a single layer film covering all of the upper surface and side surfaces of the laminated film. A plurality of light-reflective electrodes 13 connected to each other and spaced apart from each other are formed.

  As shown in FIG. 2A (b), the second semiconductor layer 4 and the light emitting layer 29 are etched in the thickness direction, leaving a part of the second semiconductor layer 4 so as to surround the outer periphery of the light reflective electrode 13. The surface of the first semiconductor layer 3 is exposed.

  As shown in FIG. 2A (c), a groove 22 reaching the surface of the substrate 2 in the exposed first semiconductor layer 3 between the adjacent second semiconductor layers 4 among the plurality of second semiconductor layers 4. Form. The groove portion 22 is formed so as to surround each peripheral portion of the second semiconductor layer 4. As a result, the separated semiconductor layer 12 that is sandwiched between the groove portions 22 and separated from the semiconductor stacked body 11 can be formed. That is, two groove portions 22 are formed between the adjacent second semiconductor layers 4. In FIG. 2A (c) and after, the description of the boundaries of the first semiconductor layer 3, the active layer 29, and the second semiconductor layer 4 is omitted.

As shown in FIG. 2A (d), after that, SiO ₂ is formed and patterned into a desired shape, thereby covering the part of the separated semiconductor layer 12, the groove 22 and the first semiconductor layer 3 with the first protection. A second protective film 15 having an opening 23 on the light reflective electrode 13 is formed over the film 14 and the light reflective electrode 13 on the second semiconductor layer 4 from the first semiconductor layer 3.

  As shown in FIG. 2A (e), a laminated film made of ASC, Ti, Pt, and Au is formed on the obtained wafer from the protective film side, and patterned into a predetermined shape by photolithography and etching processes, respectively. To do. Thereby, the first electrode 16 connected on the first semiconductor layer 3, particularly on the first semiconductor layer 3 where the first protective film 14 and the second protective film 15 are separated, is formed. At the same time, the first electrode 16 is disposed on the second protective film 15 on the second semiconductor layer 4 from the first protective film 14 on the separated semiconductor layer 11 and the trench 22. The second electrode 17 is formed in the opening 23 of the second protective film 15, that is, only on the light reflective electrode 13 of the second semiconductor layer 4 and connected to the light reflective electrode 13 through the opening 23. To do.

As shown in FIG. 2A (f), wire bonding is performed so that the first electrode 16 and the second electrode 17 are connected to each other by a wire W.
As shown in FIG. 2A (g), a support member 18 is formed on the obtained wafer so as to cover the wire W, the first electrode 16 and the second electrode 17, and the semiconductor laminate 11 that are wire-bonded. The support member 18 is formed so as to be embedded up to the top of the wire W, for example.
As shown in FIG. 2A (h), thereafter, the support member 18 is cut so that the cross section of the wire W is exposed on the first electrode 16 and the second electrode 17. Of the cut wires W, the wire connected to the first electrode 16 is the wire 19a, and the wire connected to the second electrode 17 is the wire 20a. At this time, the upper surface of the support member 18 is cut substantially flat.
As shown in FIG. 2A (i), a laminated film made of Ni and Au is formed on the upper surface of the obtained support member 18 from the support member 18 side, and each is formed into a predetermined shape by photolithography and etching processes. Pattern. Thus, an electrode pattern 19d connected to the wire 19a connected to the first electrode 16 and an electrode pattern 20d connected to the wire 20a connected to the second electrode 17 are formed.

  After that, as shown in FIG. 2A (j), laser light is irradiated from the back side of the substrate 2 (the side opposite to where the semiconductor stacked body 11 is disposed), and the substrate is separated from the semiconductor stacked body 11 and the separated semiconductor layer 12. 2 is separated. The irradiation of the laser beam here was performed using, for example, a YAG laser with an output that causes a decomposition reaction in the semiconductor layer, for example, an output of about 1 kW.

Subsequently, as shown in FIG. 2A (k), a translucent member 21 containing a phosphor is formed on the surface from which the substrate 2 is separated.
Thereafter, as shown in FIG. 2A (l), the separated semiconductor layer 12 is cut using the blade 24 from the support member 18 side, and the plurality of light emitting elements 10 are singulated.

Through such a series of steps, the first semiconductor layer can be disposed as a separated semiconductor layer in a portion where the semiconductor stacked body is divided for each unit of light emitting element. As a result, when performing the laser lift-off method, the laser beam cannot pass through this portion, and the semiconductor layer can be sufficiently decomposed and gaps can be separated, so that the substrate can be reliably separated.
In addition, when dividing by the blade, the blade cuts the separated semiconductor layer, the second protective film covering the semiconductor stacked body, and the first protective film separated from the separated semiconductor layer. Can be prevented. As a result, it is possible to prevent generation of cracks in the semiconductor laminate in the region constituting the light emitting element.
Further, since the resin is not disposed in all of the thickness direction and the separated semiconductor layer is disposed at the time of cutting with the blade, it is possible to effectively prevent resin burrs due to the pushing and pulling of the blade.

<Embodiment 2>
As shown in FIGS. 3A to 3C, one unit of the light emitting element 20 manufactured in this embodiment has two groove portions 26 arranged between adjacent semiconductor layers 12, in other words, the first groove portion. The second groove portion 26 is disposed on the outer side of the first groove portion 22 so as to surround the peripheral portion of the first groove portion 22, and the second separated semiconductor layer 27 separated from the first separated semiconductor layer 12 is disposed. It has the same configuration.
The width and depth of the second groove portion 26 are the same as those of the first groove portion 22.
Such a light-emitting element can be manufactured substantially by the manufacturing method described in the first embodiment. The step of forming the semiconductor stacked body 11 and the step of exposing the first semiconductor layer 3 (that is, the steps corresponding to FIGS. 3A (a) and 3A (b)) are the same as in the first embodiment. Therefore, illustration is abbreviate | omitted.
For example, as shown in FIG. 3A (c) instead of FIG. 2A (c) in the first embodiment, the second semiconductor layers 4 adjacent to each other among the plurality of second semiconductor layers 4 are exposed. A first groove 22 reaching the surface of the substrate 2 is formed in the first semiconductor layer 3. Thereafter, two second groove portions 26 are formed between the adjacent first groove portions 22. As a result, the second island-shaped semiconductor layer 27 sandwiched between the second groove portions 26 and separated from the first island-shaped semiconductor layer 12 can be formed.

After that, as shown in FIG. 3A (d) instead of FIG. 2A (d), SiO ₂ is deposited and patterned into a desired shape, whereby the first separated semiconductor layer 12, the second separated semiconductor layer 27, The first groove 22, the second groove 26, the first protective film 28 covering a part of the first semiconductor layer 3, and the light reflective electrode 13 on the second semiconductor layer 4 over the first semiconductor layer 3, A second protective film 15 having an opening 23 is formed on the light reflective electrode 13.

Thereafter, as shown in FIGS. 3A (e) to 3C (k), a support member is provided in the same manner as in the first embodiment, and the substrate is separated.
Subsequently, as shown in FIG. 3C (l), the separated semiconductor layer 27 is cut using the blade 24 from the support member 18 side, and a plurality of light emitting elements are separated into pieces. At this time, since the separated semiconductor layer 27 is further away from the semiconductor stacked body 11 than the separated semiconductor layer 12, cutting the separated semiconductor layer 27 may further damage the semiconductor stacked body 11 such as cracks. Can be lowered.

  Through such a series of steps, a light-emitting element with higher reliability can be manufactured in addition to the same effects as those of the first embodiment.

  The light emitting device manufacturing method according to the present invention includes various light emitting devices, in particular, a light source for illumination, a backlight light source such as an LED display and a liquid crystal display device, a traffic light, an illumination switch, various sensors and various indicators, a moving image illumination auxiliary light source, It can be suitably used for other general consumer light sources.

2 Substrate 3 First semiconductor layer 4 Second semiconductor layer 10 Light emitting element 11 Semiconductor stacked body 12 Separated semiconductor layer (first separated semiconductor layer)
13 light reflective electrode 13a Ag film 13b Ni film 13c Ti film 13d Pt film 13e AlCu film 14, 28 First protective film 15 Second protective film 16 First electrode 16a ASC film 16b Ti film 16c Pt film 16d Au film 17 First 2 electrode 18 support member 19 1st external electrode 19a, 20a, W wire 19b, 20b Ni film 19c, 20c Au film 20 2nd external electrode 21 Translucent member 22 Groove part (1st groove part)
23 Opening 24 Blade 26 Groove (second groove)
27 Spacing semiconductor layer (second spacing semiconductor layer)
29 Light emitting layer

Claims (7)

Over the first main surface of the substrate by preparing a first semiconductor layer, and the light emission layer and the second semiconductor layer in which a plurality disposed on a partial region of the first semiconductor layer, a semiconductor stacked body having,
Grooves that reach the first main surface of the substrate are formed in the first semiconductor layer between the adjacent second semiconductor layers so as to surround each peripheral edge of the second semiconductor layer, and are sandwiched between the grooves. Forming a separated semiconductor layer spaced from the semiconductor laminate;
Forming a first protective film that integrally covers the groove and the separated semiconductor layer;
A support member made of resin is provided above the surface of the first protective film opposite to the substrate and above the groove and the separated semiconductor layer,
Irradiating a laser beam from the second main surface side opposite to the first main surface of the substrate to separate the substrate from the semiconductor stacked body and the separated semiconductor layer,
A method for manufacturing a light emitting element, comprising cutting the separated semiconductor layer into a plurality of light emitting elements from the support member side using a blade.   The method for manufacturing a light emitting device according to claim 1, wherein a width of the groove is smaller than 35 μm. On the first major surface of the substrate by preparing a first semiconductor layer, a semiconductor stacked body having a light-emitting layer and the second semiconductor layer in which a plurality arranged on a part of region of the first semiconductor layer,
The first semiconductor layer in adjacent said second semiconductor layers, a groove portion reaching the first main surface of the substrate, a plurality formed so as to surround each of the peripheral portion of the second semiconductor layer, sandwiched between the groove spaced semiconductor layer forming a plurality of spaced apart from the front Symbol semiconductor laminate is,
Forming a first protective film that integrally covers the plurality of grooves and the plurality of spaced-apart semiconductor layers;
A support member made of a resin is provided on the surface of the first protective film opposite to the substrate and above the groove and the separated semiconductor layer ,
Irradiating a laser beam from the second main surface side opposite to the first main surface of the substrate to separate the substrate from the semiconductor stacked body and the separated semiconductor layer,
A method for manufacturing a light-emitting element, comprising cutting one of the plurality of spaced-apart semiconductor layers from the support member side into a plurality of light-emitting elements by using a blade.   The manufacturing method of the light emitting element of Claim 3 which cut | disconnects the said spaced apart semiconductor layer furthest from the said semiconductor laminated body among several said spaced apart semiconductor layers. Before providing the support member,
Forming a second protective film that is separated from the first protective film and the first semiconductor layer, covers the second semiconductor layer from the first semiconductor layer, and has an opening in a part of the second semiconductor layer; And
A first electrode electrically connected to the first semiconductor layer exposed separately from the first protective film and the second protective film, and extending on the second protective film; Forming a second electrode electrically connected to the second semiconductor layer,
After providing the support member, a first external electrode and a second external electrode connected to the first electrode and the second electrode, respectively, are formed, or connected to the first electrode and the second electrode, respectively. 5. The light emitting device according to claim 1, wherein the support member that exposes the first external electrode and the second external electrode is formed after the formed first external electrode and the second external electrode are formed. Manufacturing method. After forming the spaced-apart semiconductor layer, forming a light reflective electrode connected to the second semiconductor layer,
Thereafter, the second protective film is formed so as to cover the light reflective electrode,
The method for manufacturing a light emitting element according to claim 5, wherein the second electrode connected to the light reflective electrode through the opening in the second protective film is formed.   The method for manufacturing a light emitting element according to claim 1, wherein a plurality of the second semiconductor layers are arranged in a matrix direction on the first main surface of the substrate in a square shape in plan view.

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