JP2007042928A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device for emitting ultraviolet light at a high luminous efficiency. <P>SOLUTION: The light emitting device contains an n-type β-Ga<SB>2</SB>O<SB>3</SB>substrate or n-type (AlGa)<SB>2</SB>O<SB>3</SB>substrate, an interface control layer formed on the substrate, and a light emitter arranged with an AlGaN semiconductor layer formed on the interface control layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting element, and more particularly to a light emitting element that emits ultraviolet light with high luminous efficiency.

As a conventional light emitting device, a substrate having conductivity and translucency, in which an n-type layer and a p-type layer made of GaN are stacked on a SiC substrate, has been known. A light emitting element using a ₂ O ₃ substrate has been proposed. Since the Ga ₂ O ₃ substrate is a colorless and transparent conductor that transmits light from the visible region to the ultraviolet region, the light emitting element can have a vertical structure, and from the substrate side to the ultraviolet light to visible light. There is a feature that light can be extracted.

As a light-emitting device using the _Ga 2 _{O 3} substrate, by applying a nitriding treatment to _Ga 2 _{O 3} substrate, reduce the mismatch in lattice constant between the GaN-based semiconductor layers laminated thereon and _Ga 2 _{O 3} substrate In order to reduce crystal defects, it is known (for example, Patent Document 1). In addition, a light emitting device is known in which a Ga ₂ O ₃ substrate is used, an AlGaN buffer layer is formed as a buffer layer, and a double herote structure GaN-based semiconductor layer having an InGaN light emitting layer is formed on the buffer layer ( For example, Patent Document 2).
JP 2005-64153 A JP 2004-56098 A

However, a light-emitting element having a GaN-based semiconductor layer formed by nitriding a Ga ₂ O ₃ substrate has an effect of reducing lattice constant mismatch and reducing crystal defects, but ultraviolet light having a wavelength of 300 nm or less. However, it is difficult to extract ultraviolet light having a wavelength of 300 nm or less from the Ga ₂ O ₃ substrate side, and the light extraction efficiency cannot be improved. Wavelength Also, Ga ₂ O ₃ the AlGaN buffer layer was formed as a buffer layer on the substrate, the light emitting element formed of GaN-based semiconductor layer of the double heterostructure thereon in accordance with the proportion of In in the InGaN as a light-emitting layer However, it has not been considered as a light emitting element that efficiently emits ultraviolet light.

Accordingly, an object of the present invention is to provide a light emitting device that emits ultraviolet light with high luminous efficiency, and a further object of the present invention is to improve the crystallinity of the light emitting layer, thereby achieving higher efficiency and yield. An object of the present invention is to provide a light-emitting element that emits ultraviolet light with improved brightness.
Although the GaN-based semiconductor layer that can be stacked with high crystal quality on the Ga ₂ O ₃ substrate was considered to be only GaN at the technical level at the time of filing of Patent Document 2, the result of the inventor's repeated ingenuity We succeeded in stacking high-quality AlGaN, which was considered impossible.

The present invention, in order to achieve the above object, the n-type _β-Ga 2 _{O 3} or n-type _(AlGa) and a substrate transparent to ultraviolet light consisting of 2 _{O 3,} AlGaN semiconductor formed on the substrate A light-emitting element including a light-emitting portion including layers is provided.
In order to achieve the above object, the present invention provides a substrate transparent to ultraviolet light made of n-type β-Ga ₂ O ₃ or (AlGa) ₂ O _3, and interface control formed on the substrate. There is provided a light emitting device comprising: a light emitting portion composed of an AlGaN semiconductor layer formed on the interface control layer.

  In the embodiment of the present invention, the interface control layer is selected from a single interface control layer, a double layer composed of the first and second interface control layers, and a triple layer composed of the first to third interface control layers. One interface control layer can be employed. However, it is not limited to these.

As the single interface control layer, one selected from an AlGaN buffer layer, AlGaN epitaxial layer, AlGaON buffer layer, AlGaON epitaxial layer, (AlGa) ₂ O ₃ buffer layer, (AlGa) ₂ O ₃ epitaxial layer, and nitride layer An interface control layer can be employed.
Here, the buffer layer is mainly amorphous, and the epitaxial layer is mainly single crystal. The nitride layer is obtained by nitriding the surface of the substrate. The nitride layer formed on the β-Ga ₂ O ₃ substrate is GaN, and the nitride layer formed on the (AlGa) ₂ O ₃ substrate can be AlGaN, AlGaON, or a mixed state thereof. In particular, when the nitride layer is GaN, GaN that does not substantially absorb ultraviolet rays, for example, has a thickness of several monolayers is preferable.

The first interface control layer forming the double layer is preferably the above-described nitride layer, and the second interface control layer forming the double layer is preferably the buffer layer and the epitaxial layer described as the single interface control layer.
The first interface control layer forming the double layer may be a buffer layer and an epitaxial layer made of (AlGa) ₂ O ₃ , and the second interface control layer forming the double layer is a buffer layer made of AlGaN. And an epitaxial layer and a nitride layer (AlGaON).
In the double layer having the first and second interface control layers described above, the interface control layer located on the β-Ga ₂ O ₃ substrate or the (AlGa) ₂ O ₃ substrate side is referred to as the first interface here. Control layer.

The three first interface control layer forming the layer is _(AlGa) buffer layer and the epitaxial layer is preferably composed of 2 _{O 3,} a second interface control layer to form a three layer has nitride _(AlGa) 2 _{O 3} The third interface control layer forming the triple layer is preferably a buffer layer and an epitaxial layer made of AlGaN.
In the triple layer having the first and third interface control layers described above, the first to third interface control layers are formed in order from the one closer to the β-Ga ₂ O ₃ substrate or the (AlGa) ₂ O ₃ substrate. .
The layer made of AlGaN may be a gradation layer in which the N composition ratio gradually increases from below to above.

  In the embodiment of the present invention, a light emitting layer made of an AlGaN semiconductor layer is made of an n-type AlGaN layer and p-type AlGaN homojunction, non-doped, and a donor and acceptor doped AlGaN. In double heterojunction with n-type and p-type clad layers having a larger band gap, single heterojunction without n-type clad layer of double heterojunction, and double heterojunction and single heterojunction Any one light-emitting portion can be selected from those in which the light-emitting layer made of AlGaN is composed of SQW (single quantum well structure) or MQW (multiple quantum well structure).

In the light emitting device according to the present invention, a light emitting layer made of an AlGaN semiconductor is formed on an n-type β-Ga ₂ O ₃ substrate or an (AlGa) ₂ O ₃ substrate directly or via an interface control layer. In the present invention, a light-emitting layer made of a high-quality AlGaN semiconductor with few crystal defects can be obtained by overcoming conventional predictions, and ultraviolet light, particularly ultraviolet light having a wavelength of 300 nm or less, can be emitted from the light-emitting layer with high emission efficiency. Can do. A light-emitting device obtained by using an n-type β-Ga ₂ O ₃ substrate or (AlGa) ₂ O ₃ substrate, which is a colorless and transparent conductor that transmits light from the visible region to the ultraviolet region, as the substrate of the light-emitting device Can have a vertical structure. Thereby, since manufacture becomes easy, while improving a yield, since ultraviolet light can be extracted from the board | substrate side, the extraction efficiency of light can be improved.

(First embodiment)
FIG. 1 shows the structure of the light emitting device according to the first embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2, an n-type Al _x Ga _1-x N thin film (0 <x <1) 3 formed on the Ga ₂ O ₃ substrate 2, A p-type Al _x Ga _1-x N thin film (0 <x <1) 4 bonded to the n-type Al _x Ga _1-x N thin film 3 and an n-type β-Ga ₂ O ₃ substrate 2 are formed. N electrode 5, p electrode 6 formed on p-type Al _y Ga _1-y N thin film 4, electrode 7 for wire bonding lead 9 for supplying current from the outside with p electrode 6, and And bonding 8.

Here, the n-type β-Ga ₂ O ₃ substrate 2 includes a dopant selected from the group consisting of Si, Cu, Ag, Zn, Cd, Al, In, Ge, and Sn, thereby providing a predetermined conductivity. Can be controlled. In addition, the n-type Al _x Ga _1-x N thin film 3 can have a predetermined carrier concentration by including a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, light in the ultraviolet region of 300 nm or less can be obtained with high efficiency by a pn junction of an Al _x Ga _1-x N semiconductor having a simple structure, and in particular, Ga ₂ that is transparent to ultraviolet light. The emitted light can be taken out through the O ₃ substrate. Further, for example, by adopting Si as a dopant for the Ga ₂ O ₃ substrate 2 and the n-type AlGaN thin film 3, the conductivity of the Ga ₂ O ₃ substrate 4 can be controlled and n-type Al _x Ga _1-x. Since the carrier concentration of the N thin film 3 can be controlled and current can flow in the vertical direction, a vertical structure in which electrodes are formed above and below the layer structure can be adopted, and the layer configuration and manufacturing process Simplification can be achieved.
This embodiment embodies a light-emitting element that emits ultraviolet light with high efficiency and high yield, and is realized by forming an AlGaN pn junction directly on a transparent Ga ₂ O ₃ substrate. This configuration has been thought to be impossible in the past to produce high quality products, but it has overturned that prediction.

(Second Embodiment)
FIG. 2 shows a structure of a light emitting device according to the second embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2 and an n-type Al _X Ga _1-X N thin film (0 <0) formed on the Ga ₂ O ₃ substrate 2 via an interface control layer 10. x <1) 3, p-type Al _y Ga _1-y N thin film (0 <y <1) 4 bonded to the n-type Al _X Ga _1-X N thin film 3, and n-type β-Ga ₂ O ₃ An n-electrode 5 formed under the substrate 2, a p-electrode 6 formed on the p-type Al _y Ga _1-y N thin film 4, and a lead 9 for supplying current from the outside are wire-bonded by the p-electrode 6. For this purpose, a bonding electrode 7 and a bonding 8 are used.

Here, the n-type β-Ga ₂ O ₃ substrate 2 includes a dopant selected from the group consisting of Si, Cu, Ag, Zn, Cd, Al, In, Ge, and Sn, thereby providing a predetermined conductivity. Can be controlled. The n-type Al _X Ga _1-X N thin film 3 can have a predetermined carrier concentration by including a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, light in the ultraviolet region of 300 nm or less can be obtained with high efficiency by a pn junction of an Al _X Ga _1-X N semiconductor having a simple structure, and in particular, Ga ₂ that is transparent to ultraviolet light. The emitted light can be taken out through the O ₃ substrate. Further, for example, by adopting Si as a dopant for the Ga ₂ O ₃ substrate 2 and the n-type AlGaN thin film 3, the conductivity of the Ga ₂ O ₃ substrate 4 can be controlled and n-type Al _X Ga _1-X. Since the carrier concentration of the N thin film 3 can be controlled and current can flow in the vertical direction, a vertical structure in which electrodes are formed above and below the layer structure can be adopted, and the layer configuration and manufacturing process Simplification can be achieved.

Here, the interface control layer 10 is formed by nitriding treatment having an AlGaN buffer layer, an AlGaN epitaxial layer, an AlGaON buffer layer and an epitaxial layer, an (AlGa) ₂ O ₃ buffer layer and an epitaxial layer, and a thickness of several monolayers. It is one layer selected from the obtained nitride layer (GaN). In Embodiment 1, a light-emitting element that emits ultraviolet light by forming a light-emitting layer made of AlGaN directly on a β-Ga ₂ O ₃ substrate is shown; however, it is desirable to further improve the light emission efficiency. However, the provision of the interface control layer 10 makes it possible to form a light-emitting layer made of high-quality AlGaN with few crystal defects, and to emit ultraviolet light with a wavelength corresponding to the Al composition ratio with high efficiency. It became possible.
(Third embodiment)

FIG. 3 shows a structure of a light emitting device according to the third embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2, a nitride layer that is a first interface control layer 10 formed on the Ga ₂ O ₃ substrate 2, and a second interface control layer 11. in a buffer layer or an epitaxial layer of AlGaN, the buffer layer or an epitaxial layer of AlGaON, or _(AlGa) 2 and the buffer layer or an epitaxial layer of _{O 3,} n-type are stacked in pn junction thereon _{Al X Ga 1-X} N thin film (0 <x <1) 3, p-type Al _y Ga _1-y N thin film (0 <y <1) 4, and n electrode formed under n-type β-Ga ₂ O ₃ substrate 2 5, a p-electrode 6 formed on the p-type Al _y Ga _1-y N thin film 4, a bonding electrode 7 for wire-bonding a lead 9 for supplying current from the outside with the p-electrode 6, and bonding It consists of 8 Made.

Here, the n-type β-Ga ₂ O ₃ substrate may include a dopant selected from the group consisting of Si, Cu, Ag, Zn, Cd, Al, In, Ge, and Sn. Further, the n-type Al _X Ga _1-X N thin film can contain a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, in addition to the effects of the second embodiment, there are the following effects. That is, the lattice strain can be further relaxed by the first interface control layer 10 and the second interface control layer 11. As a result, the n-type Al _x Ga _1-x N thin film 3 having higher crystallinity than that of the second embodiment can be obtained, so that the light emission efficiency can be improved and the yield as the light emitting element can be improved. it can.
(Fourth embodiment)

FIG. 4 shows the structure of the light emitting device according to the fourth embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2 and a (AlGa) ₂ O ₃ buffer layer or epitaxial layer which is a first interface control layer 10 formed on the Ga ₂ O ₃ substrate 2. A third interface formed on the second interface control layer 11 and an AlGaON layer as a nitride layer which is the second interface control layer 11 formed on the first interface control layer 10. An AlGaN buffer layer or epitaxial layer serving as the control layer 12, an n-type Al _X Ga _1-X N thin film (0 <x <1) 3 stacked thereon with a pn junction, and p-type Al _y Ga _{1− It is formed on the yN} thin film (0 <y <1) 4, the n electrode 5 formed under the n-type β-Ga ₂ O ₃ substrate 2, and the p-type Al _y Ga _1-y N thin film 4. P electrode 6 and lead 9 for supplying current from the outside A bonding electrode 7 for bonding, and a bonding 8.

Here, the n-type β-Ga ₂ O ₃ substrate may include a dopant selected from the group consisting of Si, Cu, Ag, Zn, Cd, Al, In, Ge, and Sn. Further, the n-type Al _X Ga _1-X N thin film can contain a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, in addition to the effects of the second and third embodiments, there are the following effects. That is, even if lattice strain or the like remains in the second interface control layer 11, the lattice strain can be reduced by forming an AlGaN buffer layer or an AlGaN epitaxial layer by MOCVD as the third interface control layer. It is possible to achieve high luminous efficiency in the ultraviolet region.
(Fifth embodiment)

FIG. 5 shows a structure of a light emitting device according to the fifth embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2, an AlGaN buffer layer, an AlGaN epitaxial layer, an AlGaON buffer layer, an AlGaON epitaxial layer, an (AlGa) ₂ O ₃ buffer layer, and an (AlGa) ₂ O ₃ epitaxial layer. And an interface control layer 10 selected from the group consisting of a nitride layer and formed on the Ga ₂ O ₃ substrate 2, and an n-type Al _X Ga _1-X N cladding layer (0 <x <1) 22, an AlGaN light emitting layer 21 formed on the n-type Al _X Ga _1-X N cladding layer (0 <x <1) 22, and a p-type Al formed on the AlGaN light emitting layer 21 _y Ga _1-y N clad layer (0 <y <1) 23, n-electrode 5 formed under n-type β-Ga ₂ O ₃ substrate 2, and p-type Al _y Ga _1-y N clad layer Form on 23 And p electrode 6, the bonding electrodes 7 for wire bonding lead 9 supplies at p electrode 6 a current from the outside and,, and a bonding 8.

The band gap of the AlGaN light emitting layer 21 is formed to be smaller than the band gaps of the n-type Al _X Ga _1-X N cladding layer 22 and the p-type Al _y Ga _1-y N cladding layer 23.

Further, n-type _β-Ga 2 _{O 3} substrate, Si, Cu, Ag, Zn , Cd, Al, In, Ge, and may include a dopant selected from the group consisting of Sn. Further, the n-type Al _X Ga _1-X N thin film can contain a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, since the interface control layer 10 is formed between the n-type β-Ga ₂ O ₃ substrate 2 and the n-type Al _X Ga _1-X N clad layer 22, the lattice constants do not match. Can be relaxed, the crystallinity of the AlGaN light emitting layer 21 can be improved, and the light emitting element 1 has a double hetero structure, so that the emission intensity can be further increased.
(Sixth embodiment)

FIG. 6 shows a structure of a light emitting device according to the sixth embodiment. The light-emitting element 1 includes an n-type β-Ga ₂ O ₃ substrate 2 and a (AlGa) ₂ O ₃ buffer layer or epitaxial layer which is a first interface control layer 10 formed on the Ga ₂ O ₃ substrate 2. Of the first interface control layer 10 selected from the group consisting of a layer, a nitride layer (AlGaN, AlGaON, or a mixed state thereof), an AlGaN buffer layer, an AlGaN epitaxial layer, and an AlGaON buffer layer or an epitaxial layer. _(AlGa) and the second interface control layer 11 formed on the 2 _{O 3} layer, and its n-type formed on _{Al X Ga 1-X} n cladding layer (0 <x <1) 22 , n -type Al _X Ga _1-X N cladding layer (0 <x <1) AlGaN light emitting layer 21 formed on the 22, p-type formed on the AlGaN light emitting layer 21 _{Al y Ga 1-y} A cladding layer (0 <y <1) 23 , and the n electrode 5 formed under the n-type _β-Ga 2 _{O 3} substrate 2, is formed on the p-type _Al y _{Ga 1-y} N cladding layer 23 The p electrode 6, the bonding electrode 7 for wire bonding the lead 9 for supplying a current from the outside with the p electrode 6, and the bonding 8.

The band gap of the AlGaN light emitting layer 21 is formed to be smaller than the band gaps of the n-type Al _X Ga _1-X N cladding layer 22 and the p-type Al _y Ga _1-y N cladding layer 23.

Further, n-type _β-Ga 2 _{O 3} substrate, Si, Cu, Ag, Zn , Cd, Al, In, Ge, and may include a dopant selected from the group consisting of Sn. Further, the n-type Al _X Ga _1-X N thin film can contain a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, the first interface control layer 10 and the second interface control layer 11 are provided between the n-type β-Ga ₂ O ₃ substrate 2 and the n-type Al _X Ga _1-X N cladding layer 22. As in the third embodiment, the lattice constant mismatch can be relaxed and the crystallinity of the n-type Al _X Ga _1-X N cladding layer 22 can be improved. Since the light-emitting element 1 has a double hetero structure, the emission intensity can be further increased.
(Seventh embodiment)

FIG. 7 shows a structure of a light emitting device according to the seventh embodiment. The light-emitting element 1 includes an n-type _beta-Ga 2 _{O 3} substrate 2, the _Ga 2 _{O 3} is a first interface control layer 10 formed on the substrate 2 _(AlGa) of 2 _{O 3} buffer layer or an epitaxial A layer, a nitride layer (AlGaN, AlGaON, or a mixed state thereof) which is the second interface control layer 11 formed on the first interface control layer 10 and the nitride layer. A third interface control layer 12 that is an AlGaN buffer layer or an AlGaN epitaxial layer, an n-type Al _X Ga _1-X N cladding layer (0 <x <1) 22 formed thereon, and an n-type Al _X Ga An AlGaN light emitting layer 21 formed on the _1-X N cladding layer (0 <x <1) 22 and a p-type Al _y Ga _1-y N cladding layer (0 < y <1) 23 and n-type β- An n electrode 5 formed under the Ga ₂ O ₃ substrate 2, a p electrode 6 formed over the p-type Al _y Ga _1-y N cladding layer 23, and a lead 9 for supplying current from the outside It comprises a bonding electrode 7 for wire bonding with the electrode 6 and a bonding 8.

The band gap of the AlGaN light emitting layer 21 is formed to be smaller than the band gaps of the n-type Al _X Ga _1-X N cladding layer 22 and the p-type Al _y Ga _1-y N cladding layer 23.

The n-type β-Ga ₂ O ₃ substrate may include a dopant selected from the group consisting of Si, Cu, Ag, Zn, Cd, Al, In, Ge, and Sn. Further, the n-type Al _X Ga _1-X N thin film can contain a dopant selected from the group consisting of Si, Ge, Se, and Te.

According to this embodiment, the first interface control layer 10 and the second interface control layer 11 are provided between the n-type β-Ga ₂ O ₃ substrate 2 and the n-type Al _X Ga _1-X N cladding layer 22. Since the third interface control layer 12 is formed, the mismatch of lattice constants can be further reduced, the crystallinity of the AlGaN light emitting layer 21 can be improved, and the fourth embodiment Similarly to the above, since the light emitting element 1 has a double hetero structure, it is possible to further increase the light emission intensity.
(Eighth embodiment)

FIG. 8 shows a structure of a light emitting device according to the eighth embodiment. The light-emitting element 1 according to the seventh embodiment includes an n-type β-Ga ₂ O ₃ substrate 2 and a first interface control layer 10 formed on the Ga ₂ O ₃ substrate 2 (AlGa). ₂ O ₃ layer, a nitride layer (AlGaN, AlGaON, or a mixed state thereof) which is the second interface control layer 11 formed on the first interface control layer 10, and n formed thereon -Type Al _X Ga _1-X N cladding layer (0 <x <1) 22 and 4-MQW layer 24 formed on n-type Al _X Ga _1-X N cladding layer (0 <x <1) 22 And a p-type Al _y Ga _1-y N cladding layer (0 <y <1) 23 formed on the 4-MQW layer 24 and the n-type β-Ga ₂ O ₃ substrate 2. and n electrode 5, and the p electrode 6 formed on the p-type _Al y _{Ga 1-y} n cladding layer 23, the current from the outside Bonding electrode 7 for wire bonding the lead 9 with n electrode 5 for feeding and, is composed of a bonding 8 is connected to the p-electrode 6 on the printed circuit board 31 via the solder balls 30.

In this embodiment, the light-emitting element 1 has a 4-MQW 24, that is, a four-cycle multiple quantum well structure (MQW). Specifically, in the 4-MQW24, the well layer and the barrier layer have a laminated structure of Al _0.54 Ga _0.46 N (barrier layer) / Al _0.48 Ga _0.52 N (well layer). The n-type AlGaN cladding layer 22 and the p-type AlGaN cladding layer 23 are both composed of Al _0.58 Ga _0.42 N.

  According to this configuration, ultraviolet light having a peak wavelength of about 270 nm can be emitted with high efficiency, and the emission intensity can be increased by this embodiment.

Hereinafter, other configurations and emission wavelengths of the MQW and the cladding layer are shown.

Any physical or chemical vapor deposition method such as MOCVD, CVD, MBE, or sputtering can be applied to the interface control layer and the AlGaN light emitting layer according to the present invention.
Note that in Embodiment 8, an example in which the light-emitting element 1 includes the first interface control layer 10 and the second interface control layer 11 has been described. However, the light-emitting element 1 has a single configuration as in Embodiments 2 and 5. One interface control layer 10, or the first interface control layer 10, the second interface control layer 11, and the third interface control layer 12 as in the fourth and seventh embodiments may be provided.

[Industrial applicability]
The light emitting device of the present invention emits ultraviolet light by forming the light emitting portion with AlGaN. By using a substrate transparent to ultraviolet light such as β-Ga ₂ O ₃ as the substrate, it is possible to extract ultraviolet light from both the upper part and the lower part with high efficiency. As a result, it can be used in various fields such as a display and illumination.

1 shows a structure of a light-emitting element according to a first embodiment. The structure of the light emitting element which concerns on 2nd Embodiment is shown. The structure of the light emitting element which concerns on 3rd Embodiment is shown. The structure of the light emitting element which concerns on 4th Embodiment is shown. The structure of the light emitting element which concerns on 5th Embodiment is shown. The structure of the light emitting element which concerns on 6th Embodiment is shown. The structure of the light emitting element which concerns on 7th Embodiment is shown. The structure of the light emitting element which concerns on 8th Embodiment is shown.

Explanation of symbols

1 the light emitting element 2 n-type _β-Ga 2 _{O 3} substrate 3 n-type _{Al X Ga 1-X} N film 4 p-type _Al y _{Ga 1-y} N thin film 5 n electrode 6 p electrode 7 bonding electrode 8 bonding 9 leads 10 second 1 interface control layer 11 second interface control layer 12 third interface control layer 21 AlGaN light emitting layer 22 n-type Al _X Ga _1-X N cladding layer 23 p-type Al _y Ga _1-y N cladding layer 24 4 MQW layer 30 Solder ball 31 Printed circuit board

Claims (11)

a substrate transparent to ultraviolet light made of n-type β-Ga ₂ O ₃ or n-type (AlGa) ₂ O ₃ ;
A light-emitting element comprising an AlGaN semiconductor layer formed on the substrate. a substrate transparent to ultraviolet light made of n-type β-Ga ₂ O ₃ or n-type (AlGa) ₂ O ₃ ;
An interface control layer formed on the substrate;
And a light-emitting portion formed of an AlGaN semiconductor layer formed on the interface control layer. Said interface control layer, AlGaN buffer layer or an epitaxial layer, AlGaON buffer layer or an epitaxial layer, to be constituted by the _(AlGa) 2 _{O 3} buffer layer or an epitaxial layer or nitride layer formed by the nitriding treatment of the substrate The light emitting device according to claim 2, wherein the light emitting device is a light emitting device. The interface control layer includes a first interface control layer formed on the substrate made of a nitride layer formed by nitriding the substrate, an AlGaN buffer layer, an epitaxial layer, or an (AlGa) ₂ O ₃ buffer layer. The light emitting device according to claim 2, further comprising a second interface control layer formed on the first interface control layer made of an epitaxial layer. The interface control layer includes a first interface control layer formed on the substrate made of an (AlGa) ₂ O ₃ buffer layer or an epitaxial layer, an AlGaN buffer layer or an epitaxial layer, an AlGaON buffer layer or an epitaxial layer, or The light emission according to claim 2, further comprising a second interface control layer formed on the first interface control layer made of a nitride layer formed by nitriding the first interface control layer. element. The interface control layer includes a first interface control layer formed on the substrate made of an (AlGa) ₂ O ₃ buffer layer or an epitaxial layer, and a nitride layer formed by nitriding treatment of the first interface control layer A second interface control layer formed on the first interface control layer, and a third interface control layer formed on the second interface control layer made of an AlGaN buffer layer or an epitaxial layer. The light-emitting element according to claim 2.   7. The light emitting device according to claim 2, wherein the light emitting unit includes n-type AlGaN disposed on the substrate side and p-type AlGaN homojunction to the n-type AlGaN. 8. .   The light emitting unit includes an n-type AlGaN disposed on the substrate side, an AlGaN light-emitting layer having a band gap energy equal to or smaller than the n-type AlGaN bonded to the n-type AlGaN, and the AlGaN light-emitting layer. 7. The light emitting device according to claim 2, comprising p-type AlGaN having a larger band gap energy than the AlGaN light emitting layer bonded to the surface.   The AlGaN light emitting layer includes a plurality of AlGaN well layers having a band gap energy smaller than the n-type AlGaN and the p-type AlGaN, and a plurality of AlGaN barrier layers having a band gap energy larger than the plurality of AlGaN well layers, The light emitting device according to claim 8, wherein the plurality of AlGaN well layers and the plurality of AlGaN barrier layers are alternately arranged one by one.   10. The conductivity of the substrate is controlled by being doped with Si, Cu, Ag, Zu, Cd, Al, In, Ge, or Sn. Light emitting device.   11. The light emitting device according to claim 7, wherein the n-type AlGaN has a carrier concentration controlled by being doped with Si, Ge, Se, or Te.

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