JP2002314128A - Iii-v compound semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a III-V compound semiconductor that is used for light emitting elements and is excellent in uniformity. SOLUTION: This III-V compound semiconductor has a laminated structure constituted by the metal organic vapor phase growth method. In the laminated structure, a light emitting layer expressed by the general formula of Inx Gay Alz N (wherein, x+y+z=1, 0<x<=1, 0<=y<1, and 0<=z<1) is sandwiched between two layers having larger band gaps than the light emitting layer has. The two layers are expressed by the general formula of Inu Gav Alw N (wherein, u+v+w=1, 0<=u<=1, 0<=v<=1, and 0<=w<=1). In addition, the light emitting layer has a thickness of 5-500 Å and is manufactured under a pressure of 0.001-0.5 atmospheric pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a Group 3-5 compound semiconductor for a light emitting device.

[0002]

2. Description of the Related Art Conventionally, light emitting diodes in the ultraviolet, blue, and green regions (hereinafter, may be referred to as LEDs) or ultraviolet,
Blue, as a material for the light emitting element of the laser diode or the like in a green region, the general formula In _x Ga _y Al _z N (provided that, x + y +
Group 3-5 compound semiconductors represented by z = 1, 0 <x ≦ 1, 0 ≦ y <1, 0 ≦ z <1) are known. In particular, the light-emitting layer is made of the compound semiconductor, and the light-emitting layer is formed of two identical or different general formulas In having a larger band gap.
_u Ga _v Al _w N (However, u + v + w = 1,0 ≦ u ≦
1, 0 ≦ v ≦ 1, 0 ≦ w ≦ 1), a structure sandwiched and sandwiched by a layer made of a group 3-5 compound semiconductor is a so-called double hetero structure, and has a high efficiency. Is important as a light emitting element.

[0003] As a method for producing the Group 3-5 compound semiconductor, a molecular beam epitaxy (hereinafter sometimes referred to as MBE) method, a metalorganic vapor phase epitaxy (hereinafter sometimes referred to as MOVPE) method, and the like. Hydride vapor phase epitaxy (hereinafter HV)
Sometimes referred to as PE. ) Method. Above all, the MOVPE method is important because it can generally form a uniform layer with a large area as compared with the MBE method or the HVPE method.

In the MOVPE method for compound semiconductors such as GaAs and InP, the uniformity of the epitaxial film grown on the wafer surface can be improved by lowering the growth pressure. It is known that the uniformity between wafers can be improved.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a group 3-5 compound semiconductor having excellent uniformity for a light emitting device with high productivity.

[0006]

Means for Solving the Problems The present inventors have proposed the 3-5
As a result of various investigations on the growth conditions of group compound semiconductors, a high-quality uniform thin film without impairing the crystallinity of the compound semiconductor is obtained by setting the pressure and the layer thickness during the growth of the compound semiconductor in specific ranges. The inventors have found that the present invention has been achieved, and have reached the present invention.

Namely, the present invention is a group III-V compound semiconductor having a stacked structure according to (1) metal organic chemical vapor deposition, the general formula In _x Ga _y Al _z N (provided that, x + y + z
= 1, 0 <emitting layer represented by x ≦ 1,0 ≦ y <1,0 ≦ z <1) is large the same or different formula band gap than the light-emitting layer In _u Ga _v Al _w N ( Where u +
v + w = 1, 0 ≦ u ≦ 1, 0 ≦ v ≦ 1, 0 ≦ w ≦ 1), and the light emitting layer is disposed between 0.001 atm and 0.5 atm. 5Å under the following pressure
The present invention relates to a Group 3-5 compound semiconductor for a light emitting element, which is grown to a thickness of at least 500 ° or less. Further, the present invention provides (2) a method in which the light-emitting layer has a temperature of
Growth at a temperature of 0 ° C. or less and a growth rate R of the light emitting layer
(Å / min) relates to the compound semiconductor according to (1), which is grown within a range satisfying the following formula (1): 5 / (y + z) ≦ R ≦ 250 / (y + z) (1)

Further, the present invention relates to (3) S contained in the light emitting layer.
The concentration of each element of i, Ge, Cd, Zn and Mg is
Also 10¹⁹cm^-3The following (1) or (2):
It relates to a compound semiconductor. Further, the present invention provides (4) 2
Two layers each having the same or different general formula Ga_a Al _b 
N (where a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1)
(1), (2) or (3)
The compound semiconductor described above. Next, the present invention will be described in detail.
This will be described in detail.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, sapphire, ZnO, GaAs
s, Si, SiC, NdGaO ₃ (NGO), MgAl
₂ O ₄ (magnesia spinel) or the like is used. Sapphire is particularly important because it is transparent and a large-area high-quality crystal can be obtained.

In the case of the MOVPE method, the following raw materials can be used. That is, as a Group 3 raw material, trimethylgallium [(CH ₃ ) ₃ Ga, hereinafter referred to as “TMG” may be used. ], Triethyl gallium _{[(C 2 H 5) 3} G
a, may be referred to as TEG hereinafter. General formula R ₁ R such as
₂ R ₃ Ga (wherein R _1, R _2, R ₃ is a lower alkyl group.) Trialkyl gallium represented by: trimethyl aluminum _{[(CH 3) 3 Al]} , triethylaluminum [(C ₂ H ₅ ) ₃ Al, sometimes referred to as TEA hereinafter. ], Triisobutylaluminum [(i-C ₄
H ₉ ) ₃ Al], etc., where R ₁ R ₂ R ₃ Al (where R
₁ , R ₂ and R ₃ are the same as defined above. ); Trimethylamine alane [(CH ₃ ) ₃ N: AlH ₃ ]; trimethyl indium [(CH ₃ ) ₃ In; ], Triethylindium [(C ₂ H ₅ ) ₃ In]
R ₁ R ₂ R ₃ In (where R ₁ , R ₂ , R ₃
Is the same as defined above. And the like. These may be used alone or as a mixture.

[0011] Examples of Group V raw materials include ammonia, hydrazine, methylhydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, t-butylamine, ethylenediamine and the like. These may be used alone or as a mixture. Among these raw materials, ammonia and hydrazine do not contain a carbon atom in the molecule, so that the contamination of the semiconductor with carbon is small and suitable.

As the p-type dopant of the Group 3-5 compound semiconductor, a Group 2 element is preferable. Specifically, Mg, Z
Among them, n, Cd, Hg, and Be can be mentioned, and among these, Mg, which is easy to form a low-resistance p-type, is preferable. Mg
Raw materials for the dopant include biscyclopentadienyl magnesium, bismethylcyclopentadienyl magnesium, bisethylcyclopentadienyl magnesium, bis-n-propylcyclopentadienyl magnesium, bis-i-propylcyclopentadienyl magnesium, and the like. The organic metal compound represented by the general formula (RC ₅ H ₄ ) ₂ Mg (where R represents hydrogen or an alkyl group having 1 to 4 carbon atoms) is suitable because it has an appropriate vapor pressure. .

As the n-type dopant of the Group 3-5 compound semiconductor, a Group 4 element and a Group 6 element are preferable. Specific examples include Si, Ge, and O, and among these, low-resistance n
Si that can be easily molded and has high raw material purity
Is preferred. As a raw material of the Si dopant, silane (SiH ₄ ), disilane (Si ₂ H ₆ ) and the like are preferable.

Next, the method for producing a Group 3-5 compound semiconductor of the present invention will be described in more detail. In the method for producing a Group 3-5 compound semiconductor of the present invention, the Group 3-5 compound semiconductor has a laminated structure, and the laminated structure has a general formula In
_x Ga _y Al _z N (provided that, x + y + z = 1,0 <x ≦
A light emitting layer represented by 1, 0 ≦ y <1, 0 ≦ z <1) is disposed between two layers having a larger band gap than the light emitting layer. Further, the two layers
The same or different formula In _u Ga _v Al _w N
(However, u + v + w = 1, 0 ≦ u ≦ 1, 0 ≦ v ≦ 1,
0 ≦ w ≦ 1).

Further, the light emitting layer has a thickness of 5 to 500 °.
It is as follows. A more preferred range of the layer thickness is 5 to 100.
Å or less, particularly preferably 5 ° or more and 90 ° or less. When the layer thickness is less than 5 °, the layer does not function sufficiently as a light emitting layer, which is not preferable. When the layer thickness exceeds 500 °, the crystallinity is deteriorated when grown at a low temperature, which is not preferable. In addition, by reducing the thickness of the light-emitting layer, charges can be confined in the light-emitting layer with high density, so that light emission efficiency can be improved. The layer thickness of about 5 ° to 500 ° is obtained as follows. First, a layer thickness (for example, 2000 °) of a thick light-emitting layer obtained by growing the light-emitting layer under the same conditions except for the conditions for growing the light-emitting layer and the growth time is measured by secondary ion mass spectrometry. The layer thickness is divided by the growth time to determine the growth rate under the conditions. Next, in order to grow a light emitting layer having a predetermined layer thickness of 5 ° to 500 °, the predetermined layer thickness is divided by the growth rate to obtain a growth time, and conditions for growing the light emitting layer are set. Then, a light emitting layer having a predetermined thickness is obtained by growing the substrate for the growth time.

In particular, as the two layers referred to in the present invention, I
same or different general formula Ga _a Al not containing n
_b N (however, a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1)
Is preferred because of high crystallinity. In order to impart electrical conductivity to the light emitting layer, that is, the layer in contact with the active layer, the two layers are doped with impurities to form an n-type semiconductor layer and a p-type semiconductor layer, respectively. The doping may reduce the crystallinity of the two layers, resulting in a reduction in luminous efficiency. In such a case, luminous efficiency may be improved by providing a layer having a low impurity concentration as the two layers in the present invention between the active layer and the layer to be doped. Further, when the mixed crystal ratio of InN in the light emitting layer is high, thermal stability is not sufficient, and deterioration may occur during crystal growth or in a semiconductor process. For the purpose of preventing such deterioration of the light emitting layer, a layer grown next to the light emitting layer, that is, one of the two layers according to the present invention can have a protective function. In order to provide a sufficient protective function to the layer (hereinafter, sometimes referred to as a protective layer), the protective layer must have an InN mixed crystal ratio of 10% or less and an AlN
Is preferably 5% or more. More preferably, InN
The mixed crystal ratio is 5% or less, and the AlN mixed crystal ratio is 10% or more.
In order to provide the protective layer with a sufficient protective function,
The layer thickness of the protective layer is preferably from 10 to 1 μm, more preferably from 50 to 5000 °. If the thickness of the protective layer is less than 10 °, a sufficient effect may not be obtained in some cases. On the other hand, if it is larger than 1 μm, the luminous efficiency may decrease, which is not preferable.

In the present invention, at least the pressure during the growth of the light-emitting layer is from 0.001 atm to 0.5 atm, and a more preferable pressure range during the growth is 0.01 atm.
It is not less than atmospheric pressure and not more than 0.4 atm. When the growth pressure is higher than 0.5 atm, it is not preferable because sufficient uniformity cannot be obtained as a Group 3-5 compound semiconductor. On the other hand, if the growth pressure is lower than 0.001 atm, the effect of the present invention becomes inconspicuous, and furthermore, the crystallinity of the compound semiconductor may become insufficient, which is not preferable.

In the present invention, the carrier gas includes
Gases such as hydrogen, nitrogen, argon, and helium can be used alone or in combination. However, when hydrogen is contained in the carrier gas, sufficient crystallinity may not be obtained when the compound semiconductor having a high InN mixed crystal ratio is grown. In such a case, the partial pressure of hydrogen in the carrier gas is preferably reduced, and specifically, the partial pressure of hydrogen in the carrier gas is preferably 0.1 atm or less. Here, the general formula In _x Ga _y Al _z N (provided that, x + y + z
= 1, 0 <x ≦ 1, 0 ≦ y <1, 0 ≦ z <1).
The nN mixed crystal ratio may be described as x. Similarly, the values of y and z may be similarly expressed in terms of the GaN mixed crystal ratio and the AlN mixed crystal ratio. These carrier gases can be properly used. Hydrogen and helium are mentioned in that they have a large kinematic viscosity and are unlikely to cause convection. However, helium is more expensive than other gases, and when hydrogen is used, the crystallinity of the compound semiconductor may not be sufficient as described above. Since nitrogen and argon are relatively inexpensive, they can be suitably used when a large amount of carrier gas is used.

When the compound semiconductor is grown, the efficiency of taking in In is considerably smaller than that of Ga or Al. Therefore, it is generally necessary to add an In material in excess of a target InN mixed crystal ratio. As the growth pressure is lowered, the efficiency of In incorporation tends to further decrease. On the other hand, as the growth temperature is lowered, the incorporation efficiency of In tends to increase. Therefore, in order to control the InN mixed crystal ratio in the compound semiconductor, the material supply ratio, the growth pressure, and the growth temperature can be determined in consideration of the material supply capacity, crystallinity, and the like.

In the present invention, a preferable range of the growth temperature of the compound semiconductor is 500 ° C. or more and 850 ° C. or less.
If the growth temperature is lower than 500 ° C., the crystallinity of the grown layer may not be sufficient, which is not preferable. 85
If the temperature is higher than 0 ° C., it may be difficult to control the In mixed crystal ratio, which is not preferable. In the present invention, a preferable range of the growth rate of the light emitting layer is a range where the growth rate R (Å / min) is represented by the following formula (1): 5 / (y + z) ≦ R ≦ 250 / (y + z) (1) It is. If the growth rate is higher than this range, the resulting light-emitting layer may not have sufficient crystallinity, that is, if a light-emitting element is formed, it may not exhibit sufficient light-emitting characteristics, which is not preferable. On the other hand, when the growth rate is smaller than this range, the growth takes too much time and is not practical, so that it is not preferable. Here, the growth rate is obtained as follows. First, a layer thickness (for example, 2000 °) of a thick light-emitting layer obtained by growing the light-emitting layer under the same conditions except for the conditions for growing the light-emitting layer and the growth time is measured by secondary ion mass spectrometry. The layer thickness is divided by the growth time to determine the growth rate under the conditions. With this, the growth rate is obtained when the light emitting layer of 5 ° to 500 ° is grown under the same conditions except for the above growth time.

As a compound semiconductor growth apparatus used in the present invention, a general known growth apparatus can be used. Specific examples are shown in FIGS. 1, 2 and 3. In FIG. 1, a substrate is horizontally arranged on a susceptor and a source gas is supplied from above. In FIG. 2, a substrate is horizontally arranged on a susceptor, a source gas is supplied from the side, and a gas for pressing the source gas against the substrate is supplied from above. FIG.
The substrate is arranged obliquely on the susceptor and the source gas is supplied from the side. In the examples of FIGS. 1, 2 and 3,
The direction in which the source gas is supplied need not be strictly upward or from the horizontal direction, but may be any direction in which a sufficient amount of the source gas reaches the substrate. Similarly, in FIGS. 1 and 2, the orientation of the substrate need not be strictly horizontal.

In the examples shown in FIGS. 1, 2 and 3, since the temperature of the substrate or the susceptor is higher than the surroundings, the raw material and the carrier gas may be heated to cause convection. When there is convection in the reactor, the residence time of the raw material gas in the reactor tends to be long, and it tends to be difficult to form a steep layer structure.
In such a case, convection may be able to be suppressed by arranging the substrate downward. Specifically, FIG.
A structure in which the structure shown in FIGS. 2 and 3 is turned upside down is exemplified.

The examples shown in FIGS. 1, 2 and 3 are examples of an apparatus for processing a single substrate. In addition, as a reaction furnace capable of processing a large number of substrates at a time, a large number of substrates are arranged on a plane. Or a structure in which a substrate is arranged on the side surface of a polygonal susceptor called a barrel type. In particular, in an apparatus for growing a large number of wafers at once, a deposit on the susceptor generated by the growth of the compound semiconductor may hinder favorable growth in the next growth. In such a case, good growth can be achieved by cleaning the reactor using hydrogen chloride gas or the like before growth. In the examples of FIGS. 1, 2 and 3, the raw material gas is supplied from one supply pipe, but the raw materials react with each other before reaching the reaction furnace, and may hinder high-quality crystal growth. In such a case, it is preferable that the raw materials causing the reaction are led to the reaction furnace through separate pipes and mixed immediately before or in the reaction furnace.

Next, a light emitting device using the compound semiconductor obtained by the present invention will be described. FIG. 4 shows an example of a light-emitting element using the compound semiconductor. In contact with the light emitting layer 5,
When the layers 4 and 6 have different conductivity, a light emitting element having a double hetero structure is obtained. Because of the ease of growth,
Generally, a layer grown immediately before or further before the light emitting layer, that is, a layer located below the light emitting layer is made to be n-type. In addition, by interrupting the growth after the growth of the light emitting layer, a semiconductor substrate of a light emitting element having excellent uniformity and high luminous efficiency can be manufactured.

FIG. 4 shows an example in which a single layer is used as a light emitting layer. However, a layer functioning as a light emitting layer may be a layer composed of a plurality of layers. Specifically, an example in which a layer including a plurality of layers functions as a light-emitting layer includes a structure in which two or more light-emitting layers are stacked with a layer having a larger band gap.

When the light-emitting layer contains Al, impurities such as oxygen are easily taken in. Therefore, when the light-emitting layer is used as the light-emitting layer, the light-emitting efficiency may be reduced. In such a case, as the light-emitting layer does not contain Al general formula In _x Ga _y N (where
x + y = 1, 0 <x ≦ 1, 0 ≦ y <1) can be used.

By doping the light emitting layer with an impurity, light can be emitted at a wavelength different from the band gap of the light emitting layer. Since this is light emission from an impurity, it is called impurity light emission. In the case of impurity emission, the emission wavelength is determined by the composition of the group 3 element and the impurity element in the light emitting layer. in this case,
The InN mixed crystal ratio of the light emitting layer is preferably 5% or more. If the InN mixed crystal ratio is less than 5%, the emitted light is almost ultraviolet light, and it is not preferable because sufficient brightness cannot be sensed. The emission wavelength becomes longer as the In mixed crystal ratio increases, and the emission wavelength can be adjusted from purple to blue and green.

As an impurity suitable for impurity emission, a Group 2 element is preferable. Among the group II elements, Mg, Zn, C
Doping with d is preferable because of high luminous efficiency.
Particularly, Zn is preferable. The concentration of these elements is 10 ¹⁸
It is preferably from 10 to 10 ²² cm ^-3 . The light emitting layer may be simultaneously doped with Si or Ge together with these Group 2 elements. S
The preferred concentration range of i and Ge is 10 ¹⁸ to 10 ²² cm ^-3 .

In the case of impurity light emission, the light emission spectrum generally becomes broad, and the light emission spectrum may shift as the amount of injected charges increases. Therefore, when high color purity is required or when it is necessary to concentrate light emission power in a narrow wavelength range, it is more advantageous to use band edge emission. In order to realize a light-emitting element using band-edge light emission, the amount of impurities contained in the light-emitting layer must be kept low. Specifically, the concentration of each element of Si, Ge, Mg, Cd and Zn is 10 ¹⁹ c
It is preferably at most m ^−3, more preferably at most 10 ¹⁸ cm ⁻³ .

In the case of band edge emission, the emission color is 3
Determined by the composition of the group elements. When emitting light in the visible part, In
The N mixed crystal ratio is preferably 10% or more. InN mixed crystal ratio of 10
%, The emitted light is almost ultraviolet light, and it is not preferable because sufficient brightness cannot be sensed. Since the emission wavelength becomes longer as the InN mixed crystal ratio increases, the emission wavelength can be adjusted from purple to blue and green.

[0031]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. Example 1 A Group 3-5 compound semiconductor having the structure shown in FIG. 5 was manufactured by the MOVPE method, and the in-plane distribution of the light emitting state was measured by photoluminescence (hereinafter, sometimes referred to as PL). The growth apparatus used has the structure shown in FIG. A sapphire substrate 7 having a 25 mm × 25 mm sapphire C surface mirror-polished was used after organic cleaning.
For growth, a two-step growth method using GaN as a low-temperature growth buffer layer was used. A buffer layer 8 having a thickness of about 300 ° at 1/8 atm and a GaN layer 9 having a thickness of about 2.5 μm were grown using hydrogen as a carrier gas.

Next, the substrate temperature was 750 ° C., the carrier gas was nitrogen, and the carrier gas, TEG, TMI and ammonia were respectively 4 slm, 0.04 sccm and 0.6 sc
cm, 4 slm to supply In _0.3 Ga
_{A 0.7N} layer 5 was grown for 70 seconds. After maintaining the state of supplying only nitrogen and ammonia for 5 minutes as a growth interruption step, TEG, TEA and ammonia were further added at the same temperature at 0.032 sccm and 0.008 sccm, respectively.
By supplying 4 slm, a Ga _0.8 Al _0.2 N layer 10 was grown for 10 minutes. Here, slm and sccm are units of gas flow rate, and 1 slm indicates that a gas weighing 1 liter in a standard state flows per minute.
000 sccm corresponds to 1 slm.

The thicknesses of the layers 5 and 10 are as follows.
The growth rates obtained from the thicknesses of the layers grown for a longer time under the same conditions are 43 ° / min and 30 ° / min, respectively.
{, 300} can be calculated. 3-5 prepared above
Group compound semiconductor samples were prepared using He-Cd laser at 325 nm.
When PL measurement was performed at room temperature using the luminescence of Example 1 as an excitation light source, strong luminescence with a peak wavelength of about 5000 ° was observed over the entire surface of the substrate except for the surrounding area of 5 mm. FIG. 6 shows a typical PL spectrum.

Example 2 A buffer layer 8 having a thickness of about 300 ° and a GaN layer 9 having a thickness of about 2.5 μm were grown in a hydrogen carrier at 1 atm. Next, an In _0.3 Ga _0.7 N layer 5 was grown at 50 ° using a reactor pressure of 0.5 atm, a substrate temperature of 785 ° C., and a carrier gas of nitrogen. After maintaining the state of supplying only nitrogen and ammonia for 5 minutes as a growth interruption, Ga _0.8 A was further added at the same temperature.
An l _0.2 N layer 10 was grown at 300 °. When the PL measurement at room temperature was performed on the Group 3-5 compound semiconductor sample prepared as described above at room temperature in the same manner as in Example 1, the strong light emission similar to that of Example 1 was obtained over the entire surface of the substrate except for the peripheral area of 5 mm. Was observed.

Example 3 In the same manner as in Example 2, a compound semiconductor having the structure shown in FIG.
Four samples grown at 750 ° C., 725 ° C., and 700 ° C. were prepared. However, the supply amounts of the raw materials for the layers 5 and 10 were the same as in Example 1 for each sample. Each sample showed a strong PL as in Example 2. Table 1 shows the peak wavelength of the PL spectrum of the sample grown at each temperature.

[0036]

Table 1 Growth temperature of light emitting layer (° C.) 700 725 750 785 Peak wavelength of PL spectrum (nm) 5150 5200 4600 4150 As can be seen from Table 1, as the growth temperature is lowered,
It can be seen that the PL peak wavelength is longer, and the concentration of In in the layer 5 is increasing with a decrease in the growth temperature. The sample in which the layers 5 and 10 were grown at 700 ° C. was heat-treated at 1100 ° C. for 10 minutes at ８ atmospheric pressure in an atmosphere containing equal amounts of nitrogen and ammonia, but the PL spectrum did not change before and after the heat treatment. Was.

Comparative Example 1 A compound semiconductor having the structure shown in FIG. 5 was produced in the same manner as in Example 2 except that the layers 5 and 10 were grown at 1 atm and 785 ° C. When a PL spectrum was measured in the same manner as in Example 1, strong light emission was observed at the center as in Example 2. However, the portion where light emission was strong was limited to a range of a radius of 5 mm from the center. Then, the emission wavelength gradually became shorter, and the peak wavelength of the PL spectrum was 4400 ° at a portion 5 mm from the periphery of the substrate.

Example 4 In _0.2 Ga _0.8 N was added at a growth rate of 225 ° / min.
A sample having the structure shown in FIG. 5 was produced in the same manner as in Example 1 except that the growth was 0 °. When the PL spectrum was evaluated in the same manner as in Example 1, strong blue light emission was observed. FIG. 7 shows the obtained PL spectrum.

Comparative Example 2 In _0.15 Ga _0.85 N with a growth rate of 325 ° / min.
A sample having the structure shown in FIG. 5 was produced in the same manner as in Example 1 except that the sample was grown. When the spectrum was evaluated in the same manner as in Example 1, although blue emission was obtained,
The light emission intensity was 1/10 or less as compared with that of Example 1.

Example 5 After producing the compound semiconductor shown in FIG. 5 in the same manner as in Example 1, the substrate was heated to 1100 ° C. or more while supplying ammonia and nitrogen, and GaN doped with Mg was grown. . The compound semiconductor thus manufactured is annealed at 800 ° C. in nitrogen at 1 atm, and the layer doped with Mg is made into a low-resistance p-type layer. Thus, a Group 3-5 compound semiconductor epitaxial substrate for a light emitting device having excellent uniformity of emission wavelength and emission intensity is obtained.

[0041]

According to the present invention, 3 excellent in uniformity can be obtained.
Group-V compound semiconductors can be manufactured with high productivity;
Since a light-emitting element having a uniform light-emitting state can be manufactured by using the obtained Group 3-5 compound semiconductor, the present invention is extremely useful and has great industrial value.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic structure of an example of a reaction furnace used in the present invention.

FIG. 2 is a diagram showing a schematic structure of an example of a reaction furnace used in the present invention.

FIG. 3 is a diagram showing a schematic structure of an example of a reaction furnace used in the present invention.

FIG. 4 illustrates an example of a structure of a light-emitting element using a Group 3-5 compound semiconductor that can be manufactured according to the present invention.

FIG. 5 is a diagram showing a structure of a Group 3-5 compound semiconductor manufactured in Example 1.

FIG. 6 is a view showing a PL spectrum of the 3-5 compound semiconductor manufactured in Example 1.

FIG. 7 is a view showing a PL spectrum of a 3-5 compound semiconductor manufactured in Example 4.

[Explanation of symbols]

1. . . Reactor 2. . . Substrate 3. . . Susceptor . . n-type layer 5. . . 5. In _0.3 Ga _0.7 N layer . . p-type layer 7. . . Sapphire substrate 8. . . Buffer layer 9. . . GaN layer 10. . . Ga _0.8 Al _0.2 N layer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Yoshinobu Ono 6 Kitahara, Tsukuba, Ibaraki F-term (reference) 5F041 AA03 AA05 AA40 CA04 CA40 CA49 CA53 CA57 CA58 CA65 CB36

Claims (5)

[Claims] 1. A group III-V compound semiconductor having a stacked structure by a metal organic chemical vapor deposition method, the general formula an In _x Ga _y
Al _z N (however, x + y + z = 1, 0 <x ≦ 1, 0 ≦
The light emitting layer represented by y <1, 0 ≦ z <1) has the same or different general formula In _{u having} a larger band gap than the light emitting layer.
Ga _v Al _w N (However, u + v + w = 1,0 ≦ u ≦
1, 0 ≦ v ≦ 1, 0 ≦ w ≦ 1), and the light emitting layer is 5 ° to 500 ° under a pressure of 0.001 to 0.5 atm. 3-5 for a light emitting element, which is grown to the following film thickness:
Group compound semiconductor. 2. The compound semiconductor according to claim 1, wherein the light emitting layer has a thickness of 5 ° to 90 °. 3. The light-emitting layer has a temperature of 500 ° C. or more and 850 ° C. or less, and the growth rate R (Å / min) of the light-emitting layer is expressed by the following formula (1): 5 / (y + z) ≦ R ≦ 250 / (y + z) 3. The compound semiconductor according to claim 1, wherein the compound semiconductor is grown within a range satisfying (1). 4. A light emitting layer containing Si, Ge, Cd, and Zn.
And the concentration of each element of Mg is, the compound semiconductor according to any one of claims 1-3, wherein the both is 10 ¹⁹ cm ^-3 or less. 5. The two layers each having the same or different general formula Ga _a Al _b N (where a + b = 1, 0 ≦ a ≦ 1,
5. The method of claim 1, wherein 0 ≦ b ≦ 1).
The compound semiconductor according to any one of the above.