JPH08264831A - Gallium nitride compound semiconductor light-emitting element - Google Patents

Abstract

PURPOSE: To make long the distance between atoms in an acceptor and a donor by a method wherein a luminous layer is formed into a multilayer by laminating alternately layers added with the acceptor only and layers added with the donor only. CONSTITUTION: An n<+> high-carrier concentration layer 3, an n<+> high-carrier concentration layer 4 and a p-type conductivity type multilayer luminous layer 5, which is doped with Mg and is doped alternately with Zn and Si, are formed in order on a buffer layer 2. An emission peak energy hν (h: a planck constant, ν: the number of vibration of light) is shown by a formula of hν=Eg-(ED+EA)+(q<2> /εr); (ε: dielectric constant), in which an energy band gap is set as Eg, the activation energies of a donor and an acceptor are respectively set as ED and EA, the distance between the donor and the acceptor is set as (r) and a charge elementary quantity is set as (q). Accordingly, the donor and the acceptor are respectively added to separate layers in such the optimum concentration that the luminous luminance of the light-emitting element becomes maximal and moreover, by changing the thicknesses of the layers, the distance between atoms in the acceptor and the donor, which are added to interior of the luminous layer, can be made long.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device, and more particularly to a blue light emitting semiconductor light emitting device (light emitting diode) whose base material is a gallium nitride compound.

[0002]

2. Description of the Related Art Conventionally, as a light emitting diode, a gallium nitride-based (for example, AlGaInN) compound semiconductor is known. Since the compound semiconductor is a direct transition type, it has been noted that it has high emission efficiency, and that blue, which is one of the three primary colors of light, is used as the emission color.

Also in a gallium nitride-based semiconductor, an MIS in which a conventional n-layer and a semi-insulating layer (i-layer) are joined can be doped with Mg and irradiated with an electron beam or can be turned into p-type by heat treatment.
Instead of the mold, a light emitting diode having a double hetero pn junction using an AlGaN p layer, a Zn-doped InGaN light emitting layer, and an AlGaN n layer has been proposed.

In order to further improve the emission brightness, the inventors have shown an unpublished structure shown in FIG. 6 (Japanese Patent Application No. 6-11348).
4) is proposed. In this gallium nitride-based compound light emitting diode, the light emitting layer 5 formed on the light emitting element substrate
In the matrix, zinc (Zn), which is an acceptor, and silicon (Si), which is a donor, are simultaneously doped, and the junctions on both sides of the matrix have a double heterostructure.The peak wavelength is 420 to 450 nm and the emission output is 1000 mcd. Has been realized. As such a blue light emitting element, there is a demand for a blue color such as a multi-color display.

In addition, the blue of the traffic signal lamp requires a high-luminance lamp having an emission peak wavelength of about 500 nm, which is problematic in that the blue light emitting element described above has a too short wavelength. In order to set the emission peak wavelength of this blue light emitting element to the long wavelength side, it is required to shorten the width of the energy band of the light emitting layer, increase the In composition ratio of the light emitting layer, and increase the acceptor in the light emitting layer. By simultaneously adding the donors, the difference between the energy levels of the emission center can be reduced, so that the emission peak on the longer wavelength side can be obtained.

[0006]

However, if the acceptor and the donor are added to a concentration such that the emission brightness is maximized, the distance between the acceptor and the donor becomes short, and the potential energy due to the Coulomb force cannot be ignored. Since this potential energy is added to the transition energy of electrons, this is equivalent to the fact that the level difference between the acceptor and the donor is substantially increased. As a result, there is a problem that the emission wavelength shifts to the short wavelength side, and the target wavelength cannot be obtained.

Therefore, an object of the present invention is to provide a high brightness blue light emitting gallium nitride-based compound semiconductor light emitting device in which the light emission brightness is maintained at a level higher than that of the prior art and the light emission peak wavelength is on the long wavelength side. .

[0008]

In order to solve the above problems, the structure of the present invention is a gallium nitride-based compound semiconductor light emitting device having a light emitting layer to which an acceptor and a donor are added, wherein the light emitting layer is only the acceptor. It has a multi-layer structure in which the A layer to which is added and the D layer to which only the donor is added are alternately laminated. Alternatively, the junction sandwiching the light emitting layer has a double hetero structure. Alternatively or additionally, the light emitting layer comprises aluminum gallium indium nitride (Al _x Ga _Y
In _1-XY N; including X = 0, Y = 0, X = Y = 0) system. And yet further, there is an undoped layer between the A layer and the D layer.
In addition to this, the additive-free layer is also characterized by having a thickness of 50Å to 500Å. Alternatively, the light emitting layer is characterized by having an impurity concentration distribution formed by modulation doping or δ doping. Alternatively, the A layer or the D
The layer has a thickness of between 50Å and 500Å.

The present invention is also characterized in that the light emitting layer is a layer showing a p-conductivity type in which 1 × 10 ¹⁹ to 1 × 10 ²¹ / cm ^{3 of} magnesium (Mg) is added. The acceptor is any one of cadmium (Cd), zinc (Zn), beryllium (Be), calcium (Ca), or any mixture thereof. Alternatively, it is also a characteristic feature that the donor is any one of silicon (Si), germanium (Ge), tellurium (Te), and sulfur (S), or any mixture thereof. And again, the A layer and the D
It is also a characteristic configuration that each layer is composed of a layer in which the composition ratio of Al _x In _y Ga _1-xy N system is changed.

[0010]

The acceptor and the donor added to the light emitting layer are conventionally in a mixed state, and the interatomic distance between them is very short. Therefore, the inventors found that the Coulomb force between the acceptor and the donor works, and the transition energy of the atom becomes larger than the level between the acceptor and the donor. The distance between them will be maintained. That is, acceptor and donor are alternately added to the light emitting layer to form a multilayer structure, and the emission peak wavelength is adjusted by the amount of each acceptor and donor added, the layer thickness of each layer, and the base material composition ratio. By forming the acceptor and the donor in the respective layers, the Coulomb force of each other corresponds to the center interval of the respective layers on average. Therefore, the Coulomb force is sufficiently reduced compared to the conventional case where it was mixed.

The emission peak energy hν (h: Planck's constant, ν: light frequency) is the energy band gap Eg, the activation energy of the donor and the acceptor is ED, EA, and the distance between the donor and the acceptor is r,
If the elementary charge is q,

[Number 1] hν = Eg - (ED + EA ) + (q 2 / εr): represented by the expression (epsilon dielectric constant). Therefore, by adding the donor and the acceptor to separate layers at the optimum concentration that maximizes the emission brightness, and by changing the layer thickness, the substantial interatomic distance, that is, Coulomb force is controlled. The emission wavelength can be changed.

Therefore, as a way of forming a layer in which an acceptor and a donor are added, a multilayer structure in which an acceptor and a donor are alternately doped, a multilayer structure in which an undoped layer is provided between the doped layers, and δ-doping and modulation-doping are further provided. The interatomic distance between the acceptor and the donor can be controlled in the same manner even in the multi-layered structure.

[0013]

EFFECTS OF THE INVENTION By making the light emitting layer multi-layered, the interatomic distance between the acceptor and the donor added in the light emitting layer can be kept large, and the Coulomb energy between the acceptor and the donor can be made small and the emission peak wavelength can be reduced. Can be about 500 nm. The base material of the light-emitting layer can be kept in a high-luminance structure with high luminous efficiency, and a maximum brightness of 3000 mcd can be obtained.
A blue light emitting element suitable for the purpose can be obtained. Further, since the distance between the acceptor and the donor can be controlled also by the thickness of the layer, the wavelength at which the maximum brightness can be obtained can be freely controlled.

[0014]

EXAMPLES The present invention will be described below based on specific examples. (First Embodiment) The light emitting diode 10 shown in FIG. 1 has a sapphire substrate 1, on which a 500 Å AlN buffer layer 2 is formed. On the buffer layer 2, a high carrier concentration n ⁺ layer (n ⁺ -GaN) 3 composed of silicon-doped GaN with an electron concentration of 2 × 10 ¹⁸ / cm ³ and a film thickness of about 2.0 μm in order. A high carrier concentration n ⁺ layer 4 made of silicon-doped Al _x2 Ga _1-x2 N with a μm electron concentration of 2 × 10 ¹⁸ / cm ³ is formed.

On top of that, the total film thickness is about 0.5 μm.
, A p-conducting (p-type) multilayer light emitting layer 5 formed of Ga _y In _{1 -y} N doped with magnesium (Mg) and further doped with zinc (Zn) and silicon (Si) alternately is formed. Has been done. And as a clad layer on it, the film thickness is about 1.0 μm.
Hall concentration of 5 × 10 ¹⁷ / cm ³ magnesium (Mg) concentration of 1 ×
A p-layer 61 consisting of 10 ²⁰ / cm ³ of magnesium-doped Al _x1 Ga _1-x1 N, on which a hole concentration of 5 × 10 5 with a film thickness of about 0.2 μm.
¹⁷ / cm ³ magnesium concentration 1 × 10 ²⁰ / cm ³ magnesium-doped GaN second contact layer 62, with a thickness of about 500Å hole concentration 2 × 10 ¹⁷ / cm ³ magnesium concentration 2 × 10 ^A first contact layer 63 of magnesium-doped GaN of ²⁰ / cm ³ is formed. And the first
An electrode 7 made of nickel (Ni) connected to the contact layer 63 and an electrode 8 made of nickel connected to the high carrier concentration n ⁺ layer 3 are formed. Electrode 7 and electrode 8
Are electrically isolated from each other by the groove 9. In addition,
The structure shown here is only an example of the present invention, and the same effect is obtained in any structure as long as it functions as a light emitting diode having a light emitting layer having the characteristics of the present invention. In addition, not all of the drawings shown show the accurate film thickness.

Next, a method of manufacturing the light emitting diode 10 having this structure will be described. This light emitting diode 10 is
It is manufactured by vapor phase epitaxy using an organometallic compound vapor phase epitaxy method (hereinafter referred to as "M0VPE"). Gas used for semiconductor crystal growth is NH ₃ and carrier gas H ₂ or N ₂ and trimethylgallium (Ga (CH ₃ ) ₃ ) (hereinafter referred to as “TMG”) and trimethylaluminum (Al (CH ₃ ) ₃ ). (Hereinafter referred to as "TMA")
Trimethyl indium _{(In (CH 3) 3)} ( hereinafter referred to as "TMI") and die-methyl zinc _{(Zn (CH 3) 2)} ( hereinafter referred to as "DMZ") and silane (SiH ₄₎ and bis cyclopentadienyl magnesium enyl _{(Mg (C 5 H 5)} 2) ( hereinafter referred to as "CP ₂ Mg").

(1) First, a single crystal sapphire substrate 1 whose main surface is the a-plane, which has been cleaned by organic cleaning and heat treatment, is M0VP.
E Attach to the susceptor placed in the reaction chamber of the equipment. Next, the sapphire substrate 1 was vapor-phase etched at a temperature of 1100 ° C. while flowing H ₂ into the reaction chamber at a flow rate of 2 liter / min under normal pressure. (2) Next, lower the temperature to 400 ℃ and add H ₂ to 20 liter.
/ Min, NH ₃ at 10 liter / min and TMA at 1.8 × 10 ⁻⁵ mol / min to form an AlN buffer layer 2 having a thickness of about 500 Å. Then, maintaining the temperature of the sapphire substrate 1 to 1150 ° C., to form a film thickness of about 2.2 [mu] m, an electron concentration of 2 × 10 ¹⁸ / cm high carrier concentration n ⁺ layer 3 made of GaN of silicon doped ^3.

(3) Below, the composition ratio of the multilayer light emitting layer 5 (active layer) and the cladding layers 4 and 6 when the emission peak wavelength is set to about 500 nm with zinc (Zn) and silicon (Si) as the emission centers and An example of crystal growth conditions will be described. After forming the above-mentioned high carrier concentration n ⁺ layer 3, the temperature of the sapphire substrate 1 is maintained at 1000 ° C., and N ₂ or H ₂ is added to 10 liter / liter.
Min, NH ₃ 10 liter / min, TMG 1.12 × 10 ^-4 mol / min,
TMA is 0.47 × 10 ^-4 mol / min, and silane is introduced, the film thickness is 0.5 μm, and the concentration is 1 × 10 ¹⁸ / cm ³ silicon-doped Al.
_A high carrier concentration n ⁺ layer 4 made of _0.1 Ga _0.9 N was formed.

(4) Subsequently, the temperature of the sapphire substrate 1 is set to 85
Hold at 0 ℃, N ₂ or H ₂ 20 liter / min, NH ₃ 10 lit
er / min, TMG 1 x 10 ^-5 mol / min, TMI 1 x 10 ^-4 mol / min, CP ₂ Mg 2 x 10 ^-4 mol / min, and silane (SiH ₄ ).
Alternatively, diethyl zinc (DEZ) is introduced to form the light emitting layer 5. At this time, first, a silicon (Si) -doped layer 52 (D layer) is formed by using silane by about 200 Å,
Subsequently, the base material is the same material, the same thickness is about 200 Å, and the impurities to be added are switched to zinc (Zn) by DEZ to form a zinc (Zn) -doped layer 51 (A layer). Subsequently, a silicon-doped layer 52 (D layer) having a similar thickness is formed, and the acceptor zinc (Zn) and the donor silicon (Si) are alternately formed.
And are alternately added to form the light emitting layer 5 until the total thickness becomes about 0.5 μm to form a multilayer structure as shown in FIG. In this state, the multilayer light emitting layer 5 still has high resistance. The concentration of magnesium (Mg) in this light emitting layer 5 is
1 × 10 ¹⁹ / cm ³ , in each layer, the concentration of zinc (Zn) is 5 ×
It is 10 ¹⁸ / cm ³ , and the concentration of silicon (Si) is also 5 × 10 ¹⁸ / cm ³ .

(5) Subsequently, the temperature was kept at 1000 ° C., N ₂ or H ₂ was 10 liter / min, NH ₃ was 10 liter / min, and TMG was 1.12.
× 10 ^-4 mol / min, TMA 0.47 × 10 ^-4 mol / min, and CP
₂ Mg was introduced at 2 × 10 ⁻⁴ mol / min to form a p-layer 61 made of Al _0.1 Ga _0.9 N doped with magnesium (Mg) and having a thickness of about 1.0 μm. The magnesium concentration of the p-layer 61 is 1 × 10 ²⁰ / c
m is ^3. In this state, the p-layer 61 still has a resistivity of 10
It is an insulator of ⁸ Ωcm or more. Next, the temperature is kept at 1000 ° C, N ₂ or H ₂ is 10 liter / min, NH ₃ is 10 liter / min, TM
G was introduced at a rate of 1.12 × 10 ^-4 mol / min and CP ₂ Mg was introduced at a rate of 1 × 10 ^-4 mol / min, and magnesium (M
g) A second contact layer 62 made of doped GaN was formed. The concentration of magnesium in the second contact layer 62 is 1 ×
It is 10 ²⁰ / cm ³ . In this state, the second contact layer 62
Is still an insulator with a resistivity of 10 ⁸ Ωcm or more.

(6) Subsequently, the temperature is kept at 1000 ° C., N ₂ or H ₂ is 10 liter / min, NH ₃ is 10 liter / min, and TMG is 1.12.
Introduced at a rate of × 10 ^-4 mol / min and CP ₂ Mg at a rate of 4 × 10 ^-4 mol / min, and a magnesium (Mg) -doped layer with a film thickness of about 500 Å was introduced.
A first contact layer 63 made of GaN was formed. The concentration of magnesium in the first contact layer 63 is 2 × 10 ²⁰ / cm ³ . In this state, the first contact layer 63 still has
It is an insulator with a resistivity of 10 ⁸ Ωcm or more.

(7) Next, using a reflection electron beam diffractometer,
First contact layer 63, second contact layer 62, p layer 6
1 and the light emitting layer 5 were uniformly irradiated with an electron beam. The electron beam irradiation conditions are: accelerating voltage of about 10 KV, sample current of 1 μA, beam moving speed of 0.2 mm / sec, beam diameter of 60 μmφ, vacuum degree of 5.0 ×
It is 10 ^-5 Torr. Due to this electron beam irradiation, the first contact layer 63, the second contact layer 62, the p layer 61 and the light emitting layer 5 have hole concentrations of 2 × 10 ¹⁷ / cm ³ and 5 × 10 ^{17 respectively.}
/ cm ³ , 5 × 10 ¹⁷ / cm ³ , resistivity 2 Ωcm, 0.8 Ωcm, 0.8 Ω
It became a p-conductivity type semiconductor of cm. In this way, a wafer having a multilayer structure as shown in FIG. 2 was obtained. After that, each individual light emitting element (chip) is formed on the wafer as it is, but since this step is already known, the description thereof is omitted here.

The light emitting device 10 thus obtained is
Drive current 20mA, drive voltage 4V, emission peak wavelength is 480n
m 2 and emission intensity 2000 mcd. This is about 2 more than before
The emission brightness was doubled, and the emission peak wavelength was close to 500 nm required by traffic signals.

Further, zinc (Zn) in the above-mentioned multilayer light emitting layer 5
Or, each concentration of silicon (Si) is 1 ×
The range of 10 ¹⁷ to 1 × 10 ²⁰ / cm ³ is desirable in terms of improving the emission intensity.

In the above embodiment, the p-type layer 6 having the band gap of the multilayer light emitting layer 5 on both sides and the high carrier concentration n ^+.
The double heterojunction is formed so as to be smaller than the band gap of the layer 4. In the above example, InGa
The lattice constants of these three layers do not match because they are N-based and AlGaN-based, but it is desirable to use Al _x In _y Ga _1-xy N
The composition ratio x, y of each layer is adjusted using a system and selected so as to match the lattice constant of the high carrier concentration n ⁺ layer of GaN.

(Second Embodiment) The multilayer light emitting layer 5 of the first embodiment.
Is composed of an InGaN layer to which magnesium (Mg), zinc (Zn) and silicon (Si) are added. The multilayer light emitting layer 5 of the second embodiment has a GaN layer 54 as shown in FIG. , InGaN layers 53 are composed of alternating layers. The manufacturing method is the same until the formation of the high carrier concentration n ⁺ layer 3 described above,
Then, first, the temperature of the sapphire substrate 1 is maintained at 1000 ° C., N ₂ is 10 liter / min, NH ₃ is 10 liter / min, and TMG is 1.
12 × 10 ^-4 mol / min, TMA 0.47 × 10 ^-4 mol / min, and
Silane is introduced, film thickness is about 0.5 μm, silicon concentration is 1 × 10
^A high carrier concentration n ⁺ layer 4 of ¹⁹ _0.1 cm ³ of silicon-doped Al _0.1 Ga _0.9 N is formed.

Subsequently, the temperature was maintained at 850 ° C. and 20 L of N ₂ was added.
iter / min, NH ₃ 10 liter / min, TMG 1 × 10 ^-5 mol /
Min, TMI 1 × 10 ^-4 mol / min, CP ₂ Mg 2 × 10 ^-4 mol / min
Min, silane 10 × 10 ^-9 mol / min, or DEZ 2 × 10 ^-4
Introduced at a rate of mol / min to form a multilayer light emitting layer 5 of GaN / InGaN doped with magnesium (Mg) and having a total film thickness of about 0.5 μm, which is alternately doped with silicon (Si) and zinc (Zn). In this second embodiment, there is a combination in which an acceptor and a donor are added because the base material of the light emitting layer is changed and stacked, and in FIG. 3A, silicon is added to the GaN layer 54,
This is the case where zinc (Zn) was added to the InGaN layer 53 and the thickness of each was set to 100 Å. The concentration of magnesium in this light emitting layer 5 is 1 × 10 ¹⁹ / cm ³ , the concentration of zinc (Zn) is 1 × 10 ¹⁹ / cm ³ , and the concentration of silicon (Si) is 8 ×.
It is 10 ¹⁸ / cm ³ . In the case of FIG. 3B, the impurities are exchanged, zinc (Zn) is added to the GaN layer 56, and the InGaN layer 55 is added.
When silicon is added to the GaN layer 56,
Å, InGaN layer 55 is 100 Å. The concentration of magnesium in the light emitting layer 5 is 1 × 10 ¹⁹ / cm ³ , the concentration of zinc (Zn) is 5 × 10 ¹⁸ / cm ³ , and the concentration of silicon (S
The concentration of i) is also 5 × 10 ¹⁸ / cm ³ .

After forming the multilayer light emitting layer 5, the upper clad layer 6 is formed as in the first embodiment. In the case of FIG. 3 (a), this light emitting diode has a drive current of 20 mA and a drive voltage of 4 mA.
The emission peak wavelength is 500 nm and the emission intensity is 30 V
It is 00mcd. In the case of Fig. 3 (b), the emission peak wavelength is
With 490nm and emission intensity of 2500mcd, we can provide the most suitable light emitting diode.

(Third Embodiment) The light emitting diode of the third embodiment is different from the light emitting diode of the second embodiment in that as shown in FIG. 4, AlGaN / In is used as a base material of the p-conduction type light emitting layer 5.
It uses a GaN layer. Also in this example, in Fig. 4 (a)
Zinc (Zn) was added to the InGaN layer 510 and silicon was added to the AlGaN layer 511 at 5 × 10 ¹⁸ / cm ³ and 100 Å, respectively.
In FIG. 4 (b), the InGaN layer 512 is composed of
2 × 10 ¹⁸ / cm ³ of silicon is added to the AlGaN layer 513, and zinc (Zn) is added to the AlGaN layer 513 at 1 × 10 ¹⁸ / cm ³ and the thickness is 100 Å.

Similar to the above-described embodiment, the p-layer 61 is magnesium (Mg) -doped Al _x1 Ga _{1 -x1} N, and the high carrier concentration n ⁺ layer 4 is silicon (Si) -doped Al _x2 Ga ₁ It is formed by _-x2 N. The composition ratios x1 and x2 are set so that a double heterojunction in which the bandgap of the light emitting layer 5 is smaller than the bandgap of the high carrier concentration n ⁺ layer 4 and the p layer 61 is formed. The first contact layer 6
The second and second contact layers 63 are similar to those in the first and second embodiments.

Also in the light emitting element 12 thus formed, the emission peak wavelength is 490 nm and the emission brightness is 2500 to 3000 mc.
d is obtained and the effect is similar.

(Fourth Embodiment) In addition, in the structure of the multilayer light emitting layer 5 shown in FIG. 5, an undoped layer 514 having a thickness of about 50 Å is formed between layers 515 and 516 which are alternately doped (FIG. 5 (a)) or an undoped layer 5 having a uniform composition ratio
Alternating the doped layers 518 and 519 in the width of 17 (Fig. 5 (b)), or the undoped layers 52 having different composition ratios.
A very small amount of the doped layer 52 in each layer in which 0 and 521 are laminated.
The light emitting layer 5 in the case of using the δ doping method in which 2, 523 are alternately formed (FIG. 5C) may be used, or alternatively, the light emitting layer 5 formed by modulation doping in which the doping concentration is continuously changed. May be

In each of the above-mentioned examples, the concentrations of zinc (Zn) and silicon (Si) in each layer of the multi-layer light emitting layer 5 were 1 × 10 ¹⁷ to 1 × 10 5, respectively, as in the case of adding them by mixing.
The range of ²⁰ / cm ³ is desirable from the viewpoint of improving the emission intensity. The range of 1 × 10 ¹⁸ to 1 × 10 ¹⁹ / cm ³ is more preferable.
Less than 1 × 10 ¹⁸ / cm ³ is less effective, 1 × 10 ¹⁹ / cm ³
If the amount is larger, the crystallinity becomes worse.

In the above embodiment, the contact layer (or clad layer) has a high concentration of magnesium (M).
A two-layer structure of a first contact layer 63 added with g) and a second contact layer 62 added with magnesium (Mg) at a concentration lower than that of the first contact layer 63 is adopted. However, only one contact layer having a magnesium (Mg) concentration higher than the magnesium (Mg) concentration of the p-type multilayer light emitting layer 5 has electrodes 7 and 8.
It may be provided directly below. Further, GaN is used as a contact layer may be a p-type In _x Ga _1-x N mixed crystal.

The acceptor impurity is beryllium (B
You may use e), magnesium (Mg), zinc (Zn), cadmium (Cd), and mercury (Hg). Further, donor impurities include carbon (C), silicon (Si), germanium (Ge), tin (Sn), and lead.
(Pb) can be used.

Further, sulfur (S) is used as a donor impurity.
, Selenium (Se) and tellurium (Te) can also be used. p
Molding can be performed by electron beam irradiation, thermal annealing, heat treatment in N ₂ plasma gas, or laser irradiation.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a configuration of a light emitting diode according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a structure of a multi-layer light emitting layer.

FIG. 3 is a schematic configuration diagram showing a configuration of a light emitting layer according to a second example.

FIG. 4 is a schematic configuration diagram showing a configuration of a light emitting layer according to a third example.

FIG. 5 is a schematic configuration diagram showing a configuration of a light emitting layer according to a fourth example.

FIG. 6 is a schematic configuration diagram showing a configuration of a conventional light emitting diode.

[Explanation of symbols]

10 ... Light emitting diode 1 ... Sapphire substrate 2 ... Buffer layer 3 ... High carrier concentration n ⁺ layer 4 ... High carrier concentration n ⁺ layer (cladding layer) 5 ... Multi-layer light emitting layer 6 ... P layer (cladding layer) 61 ... P layer 62 ... second contact layer 63 ... first contact layer 7,8 ... electrode 9 ... groove

Claims (11)

[Claims] 1. A gallium nitride-based compound semiconductor light emitting device having a light emitting layer to which an acceptor and a donor are added, wherein the light emitting layer is an A layer to which only the acceptor is added,
A gallium nitride-based compound semiconductor light emitting device having a multi-layer structure in which the D layers to which only the donor is added are alternately laminated. 2. The gallium nitride-based compound semiconductor light emitting device according to claim 1, wherein the junction sandwiching the light emitting layer has a double hetero structure. 3. The light emitting layer comprises aluminum gallium indium nitride (Al _x Ga _Y In _1-XY N; X = 0, Y = 0, X = Y = 0).
3. The gallium nitride-based compound semiconductor light-emitting device according to claim 2, wherein 4. The gallium nitride-based compound semiconductor light emitting device according to claim 1, further comprising an undoped layer between the A layer and the D layer. 5. The gallium nitride-based compound semiconductor light emitting device according to claim 4, wherein the additive-free layer has a thickness of 50Å to 500Å. 6. The light emitting layer comprises modulation doping or δ
6. The gallium nitride-based compound semiconductor light emitting device according to claim 1, which has an impurity concentration distribution formed by doping. 7. The layer A or the layer D has a thickness of between 50Å and 500Å.
5. A gallium nitride-based compound semiconductor light emitting device according to any one of 5 to 6 8. The light emitting layer comprises magnesium (Mg) of 1 × 10.
8. The gallium nitride-based compound semiconductor light-emitting device according to claim 1, wherein the layer is a p-conductivity type layer added with ¹⁹ to 1 × 10 ²¹ / cm ³ . 9. The acceptor is one of cadmium (Cd), zinc (Zn), beryllium (Be), calcium (Ca), or any mixture thereof. The gallium nitride-based compound semiconductor light-emitting device according to the above. 10. The donor is any one of silicon (Si), germanium (Ge), tellurium (Te), and sulfur (S), or any mixture thereof. The gallium nitride-based compound semiconductor light-emitting device according to the above. 11. The A layer and the D layer are each made of Al _x
The gallium nitride-based compound semiconductor light-emitting device according to claim 1, wherein the gallium nitride-based compound semiconductor light-emitting device comprises an In _y Ga _1-xy N-based layer having a changed composition ratio.