JP2012169667A - Semiconductor light-emitting device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device which suppresses leak current sufficiently and a method of manufacturing the same.SOLUTION: There is provided a semiconductor light-emitting device comprising a laminated body including a light-emitting portion and a side surface formed by etching. Further, the semiconductor light-emitting device comprises: a first electrode provided on the side of a first surface of the laminated body; a plurality of second electrodes 40 selectively provided on a second surface opposite to the first surface; a support substrate 60 provided on the side of the second surface via a joint metal 61; and a protective film provided at least on the side surface of the laminated body excluding the second surface. The semiconductor light-emitting device comprises a plurality of dielectric films 50 between the second surface and the joint metal 61, and between a surface on the side of the second surface and the joint metal 61 in the protective film. The dielectric film 50 and a plurality of second electrodes 40 are alternately arranged. The dielectric film 50 has a film thickness greater on the side of the joint metal 61 than the second electrode 40, and a plurality of reflective films 40a are provided on a surface on the side of the joint metal 61 so as to contact the dielectric film 50.

Description

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

2. Description of the Related Art In recent years, in a semiconductor light emitting element such as an LED (Light Emitting Diode), a technique for manufacturing a laminated body including a light emitting portion on a growth substrate such as sapphire has been used. This manufacturing method is performed according to the following procedure. For example, a stacked body including a light emitting portion is grown on a substrate such as sapphire. Next, after a conductive substrate is bonded to the main surface of the laminate opposite to the growth substrate, the growth substrate is removed from the laminate. Then, electrodes are respectively formed on the surface of the stacked body from which the growth substrate is removed and the conductive substrate.

Regarding the process described above, a laser lift-off method is disclosed as a means for removing the growth substrate from the stacked body (see, for example, Patent Document 1). However, after the growth substrate is removed, the bonding metal for bonding the conductive substrate and the stacked body is exposed in an etching process for separating the stacked body. If a part of the bonding metal is peeled off or scattered by over-etching, a leakage current is generated.

JP 2009-099675 A

  The present invention provides a semiconductor light emitting device in which leakage current is sufficiently suppressed and a method for manufacturing the same.

According to one embodiment of the present invention, a first conductivity type first semiconductor layer, a second conductivity type second semiconductor layer, and light emission provided between the first semiconductor layer and the second semiconductor layer. A stacked body having a side surface formed by etching, the first electrode provided on the first surface side of the stacked body, and the first surface A plurality of second electrodes selectively provided on the second surface opposite to the first substrate; a support substrate provided on the second surface side through a bonding metal; and A protective film provided on at least the side surface excluding a second surface; a space between the second surface and the bonding metal; and a surface on the second surface side of the protective film and the bonding metal; Between the plurality of second electrodes and having a film thickness on the side of the bonding metal relative to the second electrodes. A plurality of dielectric films, the semiconductor light emitting device characterized by having a plurality of reflective films provided in contact with the surface of the side of the bonding metal in the dielectric layer is provided.

According to another aspect of the present invention, a step of forming a stacked body including a first conductive type first semiconductor, a light emitting unit, and a second conductive type second semiconductor layer on a first substrate. And forming a dielectric film on the second surface of the laminate opposite to the first substrate, and selectively removing the dielectric film to form the dielectric of the second surface. Forming a second electrode on the surface from which the body film has been removed, forming a reflective film on the upper surface of the dielectric film remaining without being removed, and forming a metal layer on the second electrode side. A step of bonding a second substrate through the metal layer, a step of peeling the first substrate from the laminate, and an etching stop of the laminate from the first main surface side. A step of selectively removing as a layer; and a step of forming a first electrode on the first surface. Method for producing a conductive light emitting device is provided.

ADVANTAGE OF THE INVENTION According to this invention, the semiconductor light-emitting device which suppressed leakage current fully and its manufacturing method are provided.

1 is a schematic cross-sectional view illustrating a semiconductor light emitting element according to a first embodiment. It is typical sectional drawing which illustrates the semiconductor light-emitting device which has another 2nd electrode. It is a typical sectional view which illustrates the composition of a dielectric film. It is a typical sectional view which illustrates a semiconductor light emitting element concerning a comparative example. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 2nd Embodiment. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 2nd Embodiment. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 2nd Embodiment. It is a schematic diagram explaining an example of the manufacturing method of the semiconductor light-emitting device which concerns on a comparative example. It is a schematic diagram explaining an example of the manufacturing method of the semiconductor light-emitting device which concerns on a comparative example. It is a schematic diagram explaining an example of the manufacturing method of the semiconductor light-emitting device which concerns on a comparative example. 6 is a schematic cross-sectional view illustrating a semiconductor light emitting element 120 according to a third embodiment. FIG. It is a typical sectional view which illustrates the composition of the 2nd electrode and a dielectric film. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 4th Embodiment. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 4th Embodiment. It is typical sectional drawing explaining an example of the manufacturing method of the semiconductor light-emitting device concerning 4th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Note that the drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the ratio coefficient of the size between the parts, and the like are not necessarily the same as actual ones. Further, even when the same part is represented, the dimensions and ratio coefficient may be represented differently depending on the drawing. Also,
In the present specification and drawings, the same elements as those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description thereof is omitted as appropriate.

(First embodiment)
FIG. 1 is a schematic cross-sectional view illustrating a semiconductor light emitting device 110 according to the first embodiment.
As illustrated in FIG. 1, the semiconductor light emitting device 110 according to the first embodiment includes a stacked body 20, a first electrode 30 selectively provided on the first main surface 20 a of the stacked body 20, and a stacked structure. 1st body 20
A second electrode 40 selectively provided on the second main surface 20b opposite to the main surface 20a, a support substrate 60 provided on the second electrode 40 side and bonded via a bonding metal 61; In the laminate 20, between the protective film 80 provided on at least the side surface 20c excluding the second main surface 20b, the region where the second electrode 40 is not provided on the second main surface 20b, and the bonding metal 61, And the dielectric film 50 provided between the surface (protective main surface 80a) on the second main surface 20b side of the protective film 80 and the bonding metal 61. The semiconductor light emitting device 110 is, for example, an LED (Li
ght Emitting Diode).

The stacked body 20 includes a first semiconductor layer 21 of a first conductivity type, a second semiconductor layer 22 of a second conductivity type,
A light emitting unit 23 provided between the first semiconductor layer 21 and the second semiconductor layer 22. In addition,
In the present embodiment, the first conductivity type is n-type and the second conductivity type is p-type.

For the dielectric film 50, for example, silicon oxide, silicon nitride, and titanium oxide are used.
The dielectric film 50 may be a single-layer film made of one selected from these materials, or a multilayer film in which a plurality of films having different refractive indexes are stacked.

The dielectric film 50 is used as a stopper film when the stacked body 20 is etched in the manufacturing process of the semiconductor light emitting device 110 described later.

When the dielectric film 50 is used as a stopper film, the bonding metal 61 under the dielectric film 50 is covered with the dielectric film 50 when the stacked body 20 is etched. That is, the dielectric film 50 covers the bonding metal 61 during the manufacturing process and prevents a part of the bonding metal 61 from being peeled off. In addition, even if overetching occurs when the stacked body 20 is etched, the dielectric film 50 prevents the bonding metal 61 from being etched. Thus, the bonding metal 61 is not scattered as dust due to over-etching.
Therefore, in the semiconductor light emitting device 110, the generation of leakage current due to the bonding metal 61 is suppressed.

The dielectric film 50 is used as a reflective film that reflects light emitted from the light emitting unit 23 of the stacked body 20. That is, the reflectance of the dielectric film 50 is higher than the reflectance of the bonding metal 61 at the wavelength of the light (emitted light) emitted from the light emitting unit 23.

Note that the second electrode 40 in the semiconductor light emitting device 110 may be in the form shown in FIG.
FIG. 2 is a schematic cross-sectional view illustrating a semiconductor light emitting element having another second electrode.
In the semiconductor light emitting device 110 shown in FIG. 2, the second electrode 40 is formed on the entire surface. That is, the second electrode 40 of the semiconductor light emitting device 110 shown in FIG. 1 is patterned, whereas the second electrode 40 of the semiconductor light emitting device 110 shown in FIG. 2 is not patterned. For this reason, the second electrode 40 shown in FIG. 2 is formed on the second main surface 20b side of the stacked body 20 from a part of the second main surface 20b to the dielectric film 50.
By using such a second electrode 40, the patterning step of the second electrode 40 is not necessary. Therefore, the manufacturing process is simplified. Further, the flatness of the second electrode 40 is improved, and the adhesion of the bonding metal 61 can be improved.

Next, a specific example of the semiconductor light emitting device 110 will be described.
The first semiconductor layer 21 and the second semiconductor layer 22 of the stacked body 20 include, for example, a nitride semiconductor.
The light emitting unit 23 has, for example, a multiple quantum well (MQW) structure. In other words, the light emitting unit 23 includes a structure in which a plurality of barrier layers and a plurality of well layers are alternately and repeatedly stacked. In addition, the light emission part 23 is a single quantum well (SQW: Single Quantum Wel.
l) It may be a structure.
In addition, the stacked body 20 may include, for example, a superlattice structure between the first semiconductor layer 21 and the light emitting unit 23. With such a structure, the light emitting unit 23 emits blue light, violet light, and the like, for example.

For example, a silicon substrate is used as the support substrate 60 that supports the stacked body 20. The joining metal 61 that joins the support substrate 60 and the second electrode 40 side of the stacked body 20 includes a first metal 611 provided on the second electrode 40 side, and a second metal 612 provided on the support substrate 60 side. Have.

As the first metal 611, for example, a multilayer metal film of Ti / Pt / Au is used. First metal 6
11, the multilayer metal film is laminated in the order of Ti / Pt / Au from the second electrode 40 side. Ti improves adhesion between the second electrode 40 and the like, for example. For example, Pt functions as a barrier layer. Au functions for bonding with the second metal 612.

For the second metal 612, for example, a multilayer metal film of Ti / Pt / Au / AuSu is used.
In the second metal 612, the multilayer metal film is Ti / Pt / Au / Au from the support substrate 60 side.
The layers are stacked in the order of Su. Ti improves the adhesion between the support substrate 60 and the like, for example. Pt
Functions as a barrier layer, for example. Au is used for thickness adjustment, for example. Au
For example, Su improves the bondability with the first metal 611.

The second electrode 40 is a p-side electrode. The second electrode 40 functions as a reflective electrode.
For example, a Ni / Ag multilayer metal film is used for the second electrode 40. In the second electrode 40, the multilayer metal film is laminated on the second main surface 20 b of the multilayer body 20 in the order of Ni / Ag. Ni
For example, the adhesion between the stacked body 20 and the second semiconductor layer 22 is improved. For example, Ag functions as a film that reflects light emitted from the light emitting unit 23.

The first electrode 30 is an n-side electrode. For the first electrode 30, for example, a multilayer metal film of Ti / Pt / Au is used. In the first electrode 30, the multilayer metal film is a first main surface 20 of the stacked body 20.
A layer of Ti / Pt / Au is laminated on a. For example, Ti improves the adhesion between the stacked body 20 and the first semiconductor layer 21. For example, Pt functions as a barrier layer. Au improves adhesion with external wiring such as bonding wires.

A protective film 80 is provided from a part of the first main surface 20a of the stacked body 20 to the side wall 20c. The protective film 80 serves to reduce leakage and protect the semiconductor light emitting device 110, for example.

The dielectric film 50 is a single layer film or a multilayer film. FIG. 3 shows the second semiconductor layer 22 of the stacked body 20.
FIG. 4 is an enlarged schematic view illustrating a part of a second electrode 40 and a dielectric film 50 disposed therebetween. Here, when the dielectric film 50 is a single layer film, the film thickness d is set so as to satisfy the following Expression 1, for example.
nd = mλ / 4 (m = 1, 3, 5...) (Formula 1)
In the above formula 1, n is the refractive index of the dielectric film 50, and λ is the wavelength of the emitted light. This formula 1
In the dielectric film 50 having the film thickness d satisfying the above, the emitted light is efficiently reflected. This
In the semiconductor light emitting device 110, the light extraction efficiency is improved.

For example, when a single-layer film of silicon oxide is used, the film thickness d of the dielectric film 50 is as follows as an example. Here, as a condition, the refractive index n of silicon oxide is 1.4. Further, GaN is used as the second semiconductor layer 22 and the refractive index of GaN is 2.4. Further, it is assumed that an Ag-based metal is used for the second electrode 40. Furthermore, the wavelength of the emitted light is set to 450.
nm. Under this condition, from Equation 1, the film thickness d of the dielectric film 50 is about 80 when m = 1.
nm.

(Comparative example)
FIG. 4 is a schematic cross-sectional view illustrating a semiconductor light emitting element 190 according to a comparative example.
The semiconductor light emitting device 190 according to the comparative example includes the stacked body 20, the first electrode 30 selectively provided on the first main surface 20 a side of the stacked body 20, and the first main surface 20 a of the stacked body 20. Second on the opposite side
A second electrode 40 selectively provided on the main surface 20 b side, and a support substrate 60 provided on the second electrode 40 side and supporting the stacked body 20 via the bonding metal 61 are provided.

The stacked body 20 includes a first semiconductor layer 21 of a first conductivity type, a second semiconductor layer 22 of a second conductivity type,
A light emitting unit 23 provided between the first semiconductor layer 21 and the second semiconductor layer 22. Also,
A protective film 80 is provided from a part of the first main surface 20a of the stacked body 20 to the side wall 20c.

In the semiconductor light emitting device 190 according to the comparative example, the dielectric film 50 is not provided. That is,
A second electrode 40 is selectively provided on the second major surface 20 b of the stacked body 20. A first metal 611 of the bonding metal 61 is provided in a region where the second electrode 40 is not provided in the second main surface 20b. For this reason, in the stage before forming the protective film 80, the 1st metal 611 will be exposed in the part which removed the laminated body 20 selectively.

Thus, when the 1st metal 611 is exposed, a part of 1st metal 611 may peel during a manufacturing process, and it may become metal dust. In addition, when overetching occurs when the stacked body 20 is selectively etched, a part of the surface of the first metal 611 is etched. As a result, the etched first metal 611 may become metal dust. The metal dust causes a leakage current of the semiconductor light emitting device 190.

On the other hand, in the semiconductor light emitting device 110 according to the first embodiment, between the region where the second electrode 40 is not provided in the second main surface 20b and the first metal 611 and the protective main surface 8.
A dielectric film 50 is provided between 0a and the first metal 611. The first metal 611 is covered with the dielectric film 50, and the first metal 611 is not exposed even at the stage before the protective film 80 is formed. Also, when the stacked body 20 is selectively etched, the dielectric film 50 serves as a stopper film even if overetching occurs. As a result, overetching reaching the first metal 611 is prevented, and generation of metal dust due to the first metal 611 is suppressed.

In the semiconductor light emitting device 190 according to the comparative example, the first metal 611 of the bonding metal 61 is provided in the region where the second electrode 40 is not provided in the second main surface 20b of the stacked body 20. As described above, for example, a Ti / Pt / Au multilayer metal film is used for the first metal 611. This multilayer metal film has a lower reflectance of emitted light than the second electrode 40. Therefore, in the region where the first metal 611 is provided on the second main surface 20b, the emitted light cannot be sufficiently reflected.

On the other hand, in the semiconductor light emitting device 110 according to the first embodiment, the dielectric film 50 is provided in a region where the second electrode 40 is not provided on the second main surface 20b. The reflectance of the emitted light in the dielectric film 50 is higher than the reflectance of the emitted light in the bonding metal 61. Therefore, the second main surface 20b can sufficiently reflect the emitted light by the second electrode 40 and the dielectric film 50.

(Second Embodiment)
Next, an example of a method for manufacturing the semiconductor light emitting device 110 according to the second embodiment will be described.
5 to 7 are schematic cross-sectional views illustrating an example of a method for manufacturing a semiconductor light emitting element according to the second embodiment.

First, as shown in FIG. 5A, a growth substrate (first substrate) made of, for example, sapphire.
After the buffer layer 71 is formed on the main surface 70a of the 70, the stacked body 20 including the first semiconductor layer 21, the light emitting unit 23, and the second semiconductor layer 22 is grown in order. For the crystal growth of the stacked body 20, for example, metal organic chemical vapor deposition (MOCVD) is used.
) Is used. In addition, crystal growth may be performed by molecular beam epitaxy (MBE). In addition to the sapphire, the growth substrate 70 includes GaN,
Various materials such as SiC, Si, and GaAs can be used.

The first semiconductor layer 21 and the second semiconductor layer 22 include, for example, a nitride semiconductor. The first semiconductor layer 21 includes, for example, an n-type GaN contact layer. The second semiconductor layer 22 includes, for example, a p-type AlGaN layer, a p-type Mg-doped GaN layer, and a p-type GaN contact layer.

The light emitting unit 23 has, for example, a multiple quantum well (MQW) structure. That is, the light emitting unit 23 is formed by alternately and repeatedly stacking a plurality of barrier layers and a plurality of well layers.

Next, as shown in FIG. 5B, dry etching is performed on a predetermined position of the stacked body 20,
A mesa structure is formed. With this mesa structure, the stress of the stacked body 20 is reduced. Thereafter, the dielectric film 50 is formed on the stacked body 20. The dielectric film 50 is used as a stopper film when the laminated body 20 described later is etched. Therefore, the dielectric film 50 is made of a material that can obtain a sufficient etching selectivity with the stacked body 20.

The dielectric film 50 is also used as a reflection film for emitted light. Therefore, the dielectric film 5
For 0, a material having a higher reflectance of emitted light than the bonding metal 61 described later is used. Dielectric film 50
For example, silicon oxide, silicon nitride, and titanium oxide are used. The dielectric film 50 is a multilayer film in which a plurality of films having different refractive indexes selected from these materials are stacked.
The dielectric film 50 may be a single layer film made of one selected from the above materials.
The dielectric film 50 is formed by, for example, a sputtering method or a vapor deposition method.
When a single layer film is applied as the dielectric film 50, the film thickness d is set so as to satisfy the above (Formula 1).

Next, as shown in FIG. 5C, the dielectric film 50 is formed by, for example, photolithography.
Is selectively etched to expose a part of the second main surface 20b of the stacked body 20. Laminate 20
The portion where the second main surface 20b is exposed is a portion where the second electrode 40 is contacted.

Next, as illustrated in FIG. 6A, the second electrode 40 is formed on the exposed portion of the second major surface 20 b of the stacked body 20 and the dielectric film 50. For example, a Ni / Ag multilayer metal film is used for the second electrode 40. The film thickness of Ni is, for example, 1 nm. The film thickness of Ag is, for example, 200 n
m. In addition, these film thicknesses are examples, and can be set as appropriate as long as the reflectance and adhesion can be secured. The second electrode 40 is formed by, for example, a vapor deposition method or a sputtering method. Here, after the second electrode 40 is formed on the entire surface, patterning may be performed as necessary. In the manufacturing method of this example, an example in which the second electrode 40 is not patterned will be described.

After forming the second electrode 40, the first metal 61 of the bonding metal 61 is formed on the second electrode 40.
1 is formed. The first metal 611 is formed by, for example, a vapor deposition method or a sputtering method. As the first metal 611, for example, a multilayer metal film of Ti / Pt / Au is used. The film thickness of Ti is, for example, 100 nm. The film thickness of Pt is, for example, 100 nm. The film thickness of Au is, for example, 4
00 nm. In the bonding metal 61, AuSn may be further formed on Au to form a multilayer metal film of Ti / Pt / Au / AuSn.

Next, as shown in FIG. 6B, the support substrate (second substrate) 6 on which the second metal 612 is formed.
Prepare 0. As the support substrate 60, for example, a silicon substrate having a plane orientation (100) is used. The plane orientation may be other orientations such as (111). The thickness of the support substrate 60 is, for example, not less than 200 μm and not more than 1 millimeter (mm).

For the second metal 612, for example, a multilayer metal film of Ti / Pt / Au / AuSu is used.
The film thickness of Ti is, for example, 100 nm. The film thickness of Pt is, for example, 150 nm. Au
The film thickness of is, for example, 400 nm. The film thickness of AuSu is, for example, 1.9 μm. Second
The metal 612 is formed on the support substrate 60 by, for example, vapor deposition or sputtering.

Next, the second metal 612 formed on the support substrate 60 and the first metal 611 on the side of the growth substrate 70 manufactured previously are faced to each other and bonded together.
The first metal 611 and the second metal 612 are joined by, for example, a load and heating. That is, with the first metal 611 and the second metal 612 facing each other, for example, 5 kgf / cm ²
As described above, a load of 500 kgf / cm ² or less is applied, and for example, heating is performed at 200 ° C. or more and 400 ° C. or less. Thereby, the 1st metal 611 and the 2nd metal 612 are mutually diffused, and these are joined.

Next, the laminate 20 is irradiated with laser light 75 from the growth substrate 70 side to perform laser lift-off. As the laser beam 75, for example, excimer laser (KrF: 248 nm)
Alternatively, a YAG laser is used. The irradiation diameter of one spot of the laser beam 75 is, for example, FIG.
The size of the mesa structure shown in

The laser beam 75 passes through the growth substrate 70 and reaches the stacked body 20. At this time, the buffer layer 71 between the growth substrate 70 and the stacked body 20 absorbs the energy of the laser beam,
Thermally decomposes. As a result, as illustrated in FIG. 6C, the growth substrate 70 is peeled from the stacked body 20.

Next, as shown in FIG. 7A, a process of etching the stacked body 20 at the position of the boundary line of the chip is performed. Here, as the etching, for example, RIE (Reacti) using chlorine gas is used.
ve Ion Etching) is used. FIG. 7A illustrates an etching state when dividing into two chips. Etching of the stacked body 20 gradually proceeds from the first major surface 20a. When the dielectric film 50 is reached, the dielectric film 50 serves as an etching stopper film. The dielectric film 50 has a sufficient etching selectivity with the stacked body 20. For example, when GaN is used as the stacked body 20 and silicon oxide is used as the dielectric film 50, the etching selectivity of GaN to silicon oxide is:
10. Thereby, the dielectric film 50 functions as a stopper film when the stacked body 20 is etched.

Next, as shown in FIG. 7B, a protective film 80 is formed. The protective film 80 serves to reduce leakage and protect the element. The protective film 80 is formed by sputtering, for example.
The film thickness of the protective film 80 is, for example, 100 nm or more and 400 nm or less.

Next, as shown in FIG. 7C, the protective film 80 is selectively removed. That is, the protective film 80 on the first main surface 20a of the stacked body 20 is selectively etched and removed. And
The protective film 80 is removed, and the first electrode 30 is formed on the exposed first main surface 20 a of the stacked body 20. For the first electrode 30, for example, a multilayer metal film of Ti / Pt / Au is used. The film thickness of Ti is, for example, 20 nm. The film thickness of Pt is, for example, 50 nm. The film thickness of Au is 700 nm, for example. The first electrode 30 is formed by, for example, a vapor deposition method.

In addition, the electrode film 41 is formed on the support substrate 60. For the electrode film 41, for example, Ti / Pt /
An Au multilayer metal film is used. The film thickness of Ti is, for example, 20 nm. The film thickness of Pt is
For example, 50 nm. The film thickness of Au is 700 nm, for example. The electrode film 41 is formed by, for example, a vapor deposition method.

Thereafter, the stacked body 20 and the support substrate 60 are cut (diced) at the position of the boundary line of the chip.
To do. Thereby, the semiconductor light emitting device 110 shown in FIG. 1 is formed. According to such a manufacturing method, the dielectric film 50 can prevent the bonding metal 61 from being peeled off or etched. Therefore, it is possible to suppress the joining metal 61 from being scattered as metal dust.

(Manufacturing method according to comparative example)
8 to 10 are schematic views illustrating an example of a method for manufacturing a semiconductor light emitting element according to a comparative example.
First, as shown in FIG. 8A, the main surface 7 of the growth substrate 70 made of, for example, sapphire.
After the buffer layer 71 is formed on 0a, the stacked body 20 including the first semiconductor layer 21, the light emitting unit 23, and the second semiconductor layer 22 is crystal-grown.

Next, as illustrated in FIG. 8B, the second electrode 40 is selectively formed on the second main surface 20 b of the stacked body 20. Subsequently, as illustrated in FIG. 8C, dry etching is performed on a predetermined position of the stacked body 20 to form a mesa structure.

Next, as illustrated in FIG. 9A, the first metal 611 is formed so as to cover the second main surface 20 b and the second electrode 40 of the stacked body 20. Subsequently, as shown in FIG. 9B, the second metal 6
A support substrate 60 on which 12 is formed is prepared. Then, the second metal 612 formed on the support substrate 60 and the first metal 611 on the side of the growth substrate 70 manufactured in advance are bonded to each other.

Next, as shown in FIG. 9C, laser light 75 is irradiated to the stacked body 20 from the growth substrate 70 side to perform laser lift-off. Thereby, the growth substrate 70 is bonded to the stacked body 20.
The first main surface 20a is peeled off.

Next, as shown in FIG. 10A, a process of etching the stacked body 20 at the position of the boundary line of the chip is performed. Here, as the etching, for example, dry etching is used.
FIG. 10A illustrates an etching state when dividing into two chips. The stacked body 20 is etched from the first major surface 20a.

Next, as shown in FIG. 10B, a protective film 80 is formed. Subsequently, as illustrated in FIG. 10C, the protective film 80 is selectively removed, and the exposed first main surface 20 a of the stacked body 20 is
The first electrode 30 is formed.

Thereafter, the stacked body 20 and the support substrate 60 are cut (diced) at the position of the boundary line of the chip.
To do. Thereby, the semiconductor light emitting device 190 according to the comparative example shown in FIG. 4 is formed.

In the method for manufacturing the semiconductor light emitting device 190 according to the comparative example, the stacked body 20 illustrated in FIG.
In this selective etching, the first metal 611 is exposed in the etched portion. For this reason, part of the first metal 611 may be peeled off before being covered with the protective film 80. In addition, when overetching occurs when the stacked body 20 is etched, the first metal 611 is also etched. Thereby, the etched first metal 611 may be scattered as metal dust. Peeled first metal 611 and scattered first metal 61
1 becomes a cause of generating a leak current in the semiconductor light emitting device 190 as metal dust.

On the other hand, in the method for manufacturing the semiconductor light emitting device 110 according to the present embodiment, the first metal 61
A dielectric film 50 is provided between 1 and the laminate 20. The first metal 611 is covered with the dielectric film 50, and the first metal 611 is not exposed even before the protective film 80 is formed. Further, when the stacked body 20 is selectively etched, even if overetching occurs, the dielectric film 50 functions as a stopper film and prevents the first metal 611 from being etched. Thereby, scattering of the first metal 611 can be suppressed.

(Third embodiment)
FIG. 11 is a schematic cross-sectional view illustrating a semiconductor light emitting device 120 according to the third embodiment.
FIG. 12 is a schematic cross-sectional view illustrating the configuration of the second electrode and the dielectric film.
As shown in FIG. 11, the semiconductor light emitting device 120 according to the third embodiment includes a stacked body 20.
The first electrode 30, the second electrode 40, the support substrate 60, the protective film 80, and the dielectric film 50 are provided.
A plurality of second electrodes 40 and dielectric films 50 are provided on the second major surface 20 b of the stacked body 20. The plurality of second electrodes 40 and the plurality of dielectric films 50 are alternately arranged. Further, each of the plurality of dielectric films 50 is provided with a plurality of reflection films 40a on the side opposite to the second main surface 20b.
The semiconductor light emitting element 120 is, for example, an LED (Light Emitting Diode).

For the dielectric film 50, for example, silicon oxide, silicon nitride, and titanium oxide are used.
The dielectric film 50 may be a single-layer film made of one selected from these materials or a multilayer film in which materials having different refractive indexes are combined.

The dielectric film 50 has a dielectric between the region where the second electrode 40 is not provided on the second main surface 20b and the first metal 611, and between the protective main surface 80a and the first metal 611. Body membrane 50
Is provided. Thereby, it is used as a stopper film when the stacked body 20 is etched in the manufacturing process of the semiconductor light emitting device 120 described later. In addition, the dielectric film 50 is used as a reflective film that reflects the light emitted from the light emitting unit 23 as necessary.

As shown in FIG. 12, the semiconductor light emitting device 120 according to the third embodiment includes a stacked body 20.
The concavo-convex structure BP is composed of a plurality of second electrodes 40 and a plurality of reflective films 40a with reference to the second main surface 20b. That is, the plurality of second electrodes 40 are provided in contact with the second main surface 20b, and the plurality of reflective films 40a are provided on the second main surface 20b via the dielectric film 50. Therefore, a step corresponding to the film thickness of the dielectric film 50 is formed between the plurality of second electrodes 40 and the plurality of reflective films 40a with respect to the second main surface 20b.

The concavo-convex structure BP has repeated steps corresponding to the film thickness of the dielectric film 50 with respect to the second major surface 20b. The plurality of second electrodes 40 and the plurality of reflective films 40a are each provided, for example, in a stripe shape along the second major surface 20b. The plurality of second electrodes 40 and the plurality of reflective films 40a may be provided in island shapes along the second main surface 20b.

Here, for the second electrode 40, for example, a multilayer metal film of Ni / Ag is used. Second electrode 4
In 0, the multilayer metal film is laminated on the second main surface 20b of the laminated body 20 in the order of Ni / Ag. The film thickness of the second electrode 40 is, for example, 200 nm.

The film thickness of the dielectric film 50 is, for example, less than 2 μm. Further, for example, a Ni / Ag multilayer metal film is used for the reflective film 40a. In the reflective film 40a, the multilayer metal film is laminated in the order of Ni / Ag on the opposite side of the dielectric film 50 from the second major surface 20b. The film thickness of the reflective film 40a is, for example, 200 nm.

The reflective film 40a has a sufficient reflectance with respect to the emitted light. The second electrode 40 is also
It has a sufficient reflectivity for the emitted light. Therefore, the concavo-convex structure BP becomes a light reflecting structure that can sufficiently reflect the emitted light. The material of the reflective film 40a may be the same as or different from the material of the second electrode 40. In addition, if the material of the reflective film 40a and the material of the 2nd electrode 40 are made the same, it will become easy to manufacture both in the same process.

In the semiconductor light emitting device 120 according to the third embodiment, the concavo-convex structure BP out of the emitted light emitted from the light emitting unit 23 by the concavo-convex structure BP provided on the second main surface 20b side of the stacked body 20.
The emitted light emitted to the side is irregularly reflected. Thereby, the angle of the light returning to the light emitting unit 23 is dispersed,
Increase luminous efficiency.

Note that, from the viewpoint of reflection of the emitted light, the dielectric film 50 has an inclined surface 50 with respect to the second main surface 20b.
You may have a. The inclined surface 50 a of the dielectric film 50 is in contact with the side surface of the second electrode 40.
Therefore, the side surface of the second electrode 40 becomes a complementary angle (180 ° −θ) of the angle θ with respect to the second main surface 20b of the inclined surface 50a. Depending on the setting of the angle θ, the light reflection characteristic at the concavo-convex structure BP changes.

(Fourth embodiment)
Next, an example of a method for manufacturing the semiconductor light emitting device 120 according to the fourth embodiment will be described.
13 to 15 are schematic cross-sectional views illustrating an example of a method for manufacturing the semiconductor light emitting device 120 according to the fourth embodiment.

First, as shown in FIG. 13A, after the buffer layer 71 is formed on the main surface 70a of the growth substrate 70 made of, for example, sapphire, the first semiconductor layer 21, the light emitting unit 23, and the second semiconductor layer are formed. The stacked body 20 including 22 is crystal-grown. For crystal growth, for example, MOCVD is used. In addition, crystal growth may be performed by MBE. As the growth substrate 70,
In addition to sapphire, various materials such as GaN, SiC, Si, and GaAs can be used.

The first semiconductor layer 21 and the second semiconductor layer 22 include, for example, a nitride semiconductor. The first semiconductor layer 21 includes, for example, an n-type GaN contact layer. The second semiconductor layer 22 includes, for example, a p-type AlGaN layer, a p-type Mg-doped GaN layer, and a p-type GaN contact layer. The light emitting unit 23 has, for example, an MQW structure. That is, the light emitting unit 23 is formed by alternately and repeatedly stacking a plurality of barrier layers and a plurality of well layers.

Next, as illustrated in FIG. 13B, dry etching is performed on a predetermined position of the stacked body 20 to form a mesa structure. With this mesa structure, the stress of the stacked body 20 is reduced. Thereafter, the dielectric film 50 is formed on the stacked body 20. The dielectric film 50 is used as a stopper film when the laminated body 20 described later is etched. Accordingly, as the dielectric film 50, the laminate 2
A material that can obtain a sufficient etching selectivity with respect to 0 is used.

For the dielectric film 50, for example, silicon oxide, silicon nitride, and titanium oxide are used.
The dielectric film 50 is a multilayer film in which different kinds of materials selected from these materials are combined. The dielectric film 50 may be a single layer film made of one selected from the above materials. The dielectric film 50 is formed by, for example, a sputtering method or a vapor deposition method.

Next, as shown in FIG. 13C, the dielectric film 5 is formed by, for example, photolithography.
0 is selectively etched, and a part of the second main surface 20b of the stacked body 20 is exposed. The portion where the second main surface 20b of the stacked body 20 is exposed is a portion where the second electrode 40 is contacted. Here, the dielectric film 50 is etched in accordance with the positions of the plurality of second electrodes 40 of the concavo-convex structure BP.

Next, as illustrated in FIG. 14A, the reflective metal film 40 m is formed on the exposed portion of the second main surface 20 b of the stacked body 20 and the dielectric film 50. For the reflective metal film 40m, for example, Ni / A
g multilayer metal film is used. The film thickness of Ni is, for example, 1 nm. The film thickness of Ag is, for example, 200 nm. In addition, these film thicknesses are examples, and can be set as appropriate as long as the reflectance and adhesion can be secured. The reflective metal film 40m is formed, for example, by vapor deposition or sputtering.
Here, the reflective metal film 40 m formed on the exposed portion of the second main surface 20 b of the stacked body 20 becomes the second electrode 40. The reflective metal film 40m formed on the dielectric film 50 is formed of the reflective film 4
0a. That is, the second electrode 40 and the reflective film 40a are formed in the same process by forming the reflective metal film 40m.

After the second electrode 40 and the reflective film 40a are formed, the first metal 611 of the bonding metal 61 is formed thereon. The first metal 611 is formed by, for example, a vapor deposition method or a sputtering method. As the first metal 611, for example, a multilayer metal film of Ti / Pt / Au is used. The film thickness of Ti is, for example, 100 nm. The film thickness of Pt is, for example, 100 nm. The film thickness of Au is 400 nm, for example. In the bonding metal 61, AuS is further formed on Au.
n may be formed into a multilayer metal film of Ti / Pt / Au / AuSn.
The first metal 611 reflects the uneven shape of the uneven structure BP.

Next, as shown in FIG. 14B, a support substrate 60 on which the second metal 612 is formed is prepared. As the support substrate 60, for example, a silicon substrate having a plane orientation (100) is used. The plane orientation may be other orientations such as (111). The thickness of the support substrate 60 is, for example, 200 μm
m or more and 1 millimeter (mm) or less.

For the second metal 612, for example, a multilayer metal film of Ti / Pt / Au / AuSu is used.
The film thickness of Ti is, for example, 100 nm. The film thickness of Pt is, for example, 150 nm. Au
The film thickness of is, for example, 400 nm. The film thickness of AuSu is, for example, 1.9 μm. Second
The metal 612 is formed on the support substrate 60 by, for example, vapor deposition or sputtering.

Next, the second metal 612 formed on the support substrate 60 and the first metal 611 on the side of the growth substrate 70 manufactured previously are faced to each other and bonded together.
The first metal 611 and the second metal 612 are joined by, for example, a load and heating. That is, with the first metal 611 and the second metal 612 facing each other, for example, 5 kgf / cm ²
As described above, a load of 500 kgf / cm ² or less is applied, and for example, heating is performed at 200 ° C. or more and 400 ° C. or less. Thereby, the 1st metal 611 and the 2nd metal 612 are mutually diffused, and these are joined.
Since the first metal 611 reflects the concavo-convex shape of the concavo-convex structure BP, the bonding strength between the first metal 611 and the second metal 612 is higher than that in the flat shape.

Next, the laminate 20 is irradiated with laser light 75 from the growth substrate 70 side to perform laser lift-off. As the laser beam 75, for example, excimer laser (KrF: 248 nm)
Alternatively, a YAG laser is used. The irradiation diameter of one spot of the laser beam 75 is, for example, FIG.
It may be adjusted to the size of the mesa structure shown in b).

The laser beam 75 passes through the growth substrate 70 and reaches the stacked body 20. At this time, the buffer layer 71 between the growth substrate 70 and the stacked body 20 absorbs the energy of the laser beam,
Thermally decomposes. As a result, as shown in FIG. 14C, the growth substrate 70 is peeled from the stacked body 20.

Next, as shown in FIG. 15A, a process of etching the stacked body 20 at the position of the boundary line of the chip is performed. Here, as the etching, for example, RIE using a chlorine-based gas is used. FIG. 15A illustrates an etching state when dividing into two chips. Etching of the stacked body 20 gradually proceeds from the first major surface 20a. When the dielectric film 50 is reached, the dielectric film 50 serves as an etching stopper. The dielectric film 50 has a sufficient etching selectivity with the stacked body 20. For example, when GaN is used as the stacked body 20 and silicon oxide is used as the dielectric film 50, the etching selectivity of GaN to silicon oxide is 10. Thereby, the dielectric film 50 functions as a stopper film when the stacked body 20 is etched.

Next, as shown in FIG. 15B, a protective film 80 is formed. The protective film 80 serves to reduce leakage and protect the element. The protective film 80 is formed by sputtering, for example. The film thickness of the protective film 80 is, for example, 100 nm or more and 400 nm or less.

Next, as shown in FIG. 15C, the protective film 80 is selectively removed. That is, the protective film 80 on the first main surface 20a of the stacked body 20 is selectively etched and removed. Then, the protective film 80 is removed, and the first electrode 30 is formed on the exposed first main surface 20a of the stacked body 20. For the first electrode 30, for example, a multilayer metal film of Ti / Pt / Au is used. The film thickness of Ti is, for example, 20 nm. The film thickness of Pt is, for example, 50 nm. The film thickness of Au is 700 nm, for example. The first electrode 30 is formed by, for example, a vapor deposition method.

In addition, the electrode film 41 is formed on the support substrate 60. For the electrode film 41, for example, Ti / Pt /
An Au multilayer metal film is used. The film thickness of Ti is, for example, 20 nm. The film thickness of Pt is
For example, 50 nm. The film thickness of Au is 700 nm, for example. The electrode film 41 is formed by, for example, a vapor deposition method.

Thereafter, the stacked body 20 and the support substrate 60 are cut (diced) at the position of the boundary line of the chip.
To do. As a result, the semiconductor light emitting device 120 shown in FIG. 11 is formed. According to such a manufacturing method, the dielectric film 50 can prevent the bonding metal 61 from being peeled off or etched. Therefore, it is possible to suppress the joining metal 61 from being scattered as dust.

As mentioned above, although embodiment of this invention and its modification were demonstrated, this invention is not limited to these examples. For example, in each of the above-described embodiments and modifications, the first conductivity type is described as n-type and the second conductivity type is defined as p-type. However, the present invention describes the first conductivity type as p-type, 2
It is possible to implement the n conductivity type.

Further, for example, an optoelectronic integrated circuit (Opto Electronic Integrated Circuit) in which an electronic circuit capable of processing an optical signal emitted from the semiconductor light emitting device 110 is integrated on the same support substrate 60.
) Is also included in this embodiment.

In addition, each element included in each of the above-described embodiments can be combined as long as technically possible, and combinations thereof are also included in the scope of the present invention as long as they include the features of the present invention.
In addition, in the category of the idea of the present invention, those skilled in the art can conceive of various changes and modifications, and it is understood that these changes and modifications also belong to the scope of the present invention. .

DESCRIPTION OF SYMBOLS 20 ... Laminated body, 20a ... 1st main surface, 20b ... 2nd main surface, 20c ... Side surface, 21 ... 1st semiconductor layer, 22 ... 2nd semiconductor layer, 23 ... Light emission part, 30 ... 1st electrode, 40 ... Second electrode, 40a ...
Reflective film, 40 m ... reflective metal film, 41 ... electrode film, 50 ... dielectric film, 50a ... inclined surface, 60 ...
Support substrate 61. Bonding metal 70. Growth substrate 70 a Main surface 71 Buffer layer 75
... Laser beam, 80 ... Protective film, 80a ... Protective main surface, θ ... Angle, 110, 120, 190 ... Semiconductor light emitting element, 611 ... First metal, 612 ... Second metal, d ... Film thickness

Claims (9)

An element end side including a first conductivity type first semiconductor layer, a second conductivity type second semiconductor layer, and a light emitting portion provided between the first semiconductor layer and the second semiconductor layer; A laminate having a side surface formed by etching, and
A first electrode provided on the first surface side of the laminate;
A plurality of second electrodes selectively provided on a second surface opposite to the first surface;
A support substrate provided on the second surface side via a bonding metal;
A protective film provided on at least the side surface excluding the second surface in the laminate;
Provided between the second surface and the bonding metal, and between the surface on the second surface side of the protective film and the bonding metal, and alternately disposed with the plurality of second electrodes. A plurality of dielectric films having a film thickness closer to the bonding metal than the second electrode;
A plurality of reflective films provided in contact with the surface on the side of the bonding metal in the dielectric film;
A semiconductor light emitting element comprising: In the wavelength of light emitted from the light emitting unit, the reflectance of the dielectric film is higher than the reflectance of the bonding metal,
2. The semiconductor light emitting element according to claim 1, wherein the dielectric film includes a multilayer film in which a plurality of films having different refractive indexes are stacked. The semiconductor light emitting element according to claim 1, wherein the reflective film is a multilayer metal film containing at least Ag. 4. The semiconductor light emitting element according to claim 1, wherein the reflection film is a multilayer metal film in which Ni and Ag are stacked in this order from the second surface toward the bonding metal. 5. . 5. The semiconductor light emitting element according to claim 1, wherein the dielectric film has an inclined surface inclined with respect to the second surface. The second electrode includes a multilayer metal film laminated in the order of Ni and Ag in a direction from the second surface toward the bonding metal,
6. The semiconductor light emitting element according to claim 1, wherein the bonding metal includes a multilayer metal film in which Ti, Pt, and Au are laminated in this order from the second electrode side toward the support substrate. Forming a stack including a first conductivity type first semiconductor, a light emitting portion, and a second conductivity type second semiconductor layer on a first substrate;
Forming a dielectric film on the second surface of the laminate opposite to the first substrate;
The dielectric film is selectively removed and a second surface of the second surface is removed from the second surface.
Forming an electrode;
Forming a reflective film on the upper surface of the dielectric film remaining without being removed;
Forming a metal layer on the second electrode side and bonding the second substrate through the metal layer;
Peeling the first substrate from the laminate;
Selectively removing the laminate from the first main surface side as the dielectric film as an etching stop layer;
Forming a first electrode on the first surface;
A method of manufacturing a semiconductor light emitting device, comprising: The step of forming the second electrode includes forming a multilayer metal film in which Ni and Ag are laminated in this order from the second surface,
8. The method of manufacturing a semiconductor light emitting element according to claim 7, wherein the step of bonding the second substrate includes forming a multilayer metal film in which Ti, Pt, and Au are stacked in this order from the second electrode. In the step of forming the second electrode, the selective removal of the dielectric film is performed such that a plurality of exposed portions of the second surface and a plurality of portions of the dielectric film are alternately arranged. The manufacturing method of the semiconductor light-emitting device in any one of Claim 7 or 8 including doing.

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