JP3064891B2 - Group 3-5 compound semiconductor, method of manufacturing the same, and light emitting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Group 3-5 compound semiconductor, a method for producing the same, and a light emitting device.

[0002]

Formula as a material for a light-emitting element such as the Related Art Ultraviolet or blue light emitting diodes or ultraviolet or blue laser diodes In _x Ga _y Al _z N (provided that, x +
Group 3-5 compound semiconductors represented by y + z = 1, 0 ≦ x <1, 0 <y ≦ 1, 0 ≦ z <1) are known. Less than,
In the above general formula, x, y, and z are each an In concentration, G
Sometimes referred to as a concentration and Al concentration. The group III-V compound semiconductors having an In concentration of 10% or more can adjust the emission wavelength in the visible region according to the In concentration, and are therefore important for display applications. By the way, the Group III-V compound semiconductor has the following major problems when a light emitting device using the same is put into practical use. That is, first, there is no suitable substrate that can be used for crystal growth of the group III-V compound semiconductor, and second, there is a problem of thermal stability of the group III-V compound semiconductor. Hereinafter, this point will be described in detail. First, the first problem is that the group III-V compound semiconductors have been tried to be formed on various substrates such as sapphire, GaAs, ZnO, etc.
The reason is that crystals of sufficiently high quality have not been obtained because they are significantly different from Group 5 compound semiconductors. Therefore, the 3-5
Attempts have been made to first grow a GaN crystal having similar lattice constants and chemical properties to the group III compound semiconductor, and then grow the group 3-5 compound semiconductor thereon to obtain an excellent crystal ( JP-B-55-3834). However, even in this case, it is known that as the In concentration increases, the deviation of the lattice constant between the group III-V compound semiconductor and GaN increases, the crystallinity decreases, and the number of defects increases. Therefore, it has been difficult to manufacture the Group 3-5 compound semiconductor having a high quality and a high InN mixed crystal ratio.

Second, it is known that, among the compound semiconductors, those containing In have a considerably lower decomposition temperature than those containing no In. For example, GaN, AlN and their mixed crystals are relatively stable even at 1000 ° C. or higher,
The thermal decomposition temperature of InN is about 600 ° C. Therefore, I
Although the compound semiconductor containing n depends on the In composition, generally, at a temperature higher than 1000 ° C., the crystal deteriorates and the number of defects increases.

In order to manufacture a light emitting device which can be driven at a low voltage, it is necessary to sandwich an active layer between p-type and n-type current injection layers. It is known that it is easy to produce an n-type compound semiconductor but very difficult to produce a p-type compound semiconductor.

[0005] In order to obtain high p-type conduction, a post-treatment such as a thermal annealing treatment or an electron beam irradiation treatment may be effective for a layer doped with an acceptor-type impurity. Generally, these treatments can be expected to have a high effect when the layer doped with the acceptor-type impurity is exposed on the surface. For this reason, it is preferable that the p-type current injection layer be grown after the active layer. Further, it is known that a compound semiconductor that does not contain In as compared with a semiconductor that contains In can easily exhibit p-type conductivity. Therefore, Ga _{x "} Aly _" N containing no In is contained in the p-type current injection layer.
(However, x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <
1) is used. However, it is necessary to grow at a temperature exceeding 1000 ° C. in order to obtain the Ga _{x ″ A y ″} N exhibiting good p-type conduction. Therefore, p
There is a problem that the active layer containing In deteriorates while the Ga _{x ″ A y ″} N of the mold is grown at a temperature exceeding 1000 ° C.

[0006]

SUMMARY OF THE INVENTION The present invention provides a method of growing a high-quality group III-V compound semiconductor with few defects and a layer containing In, and then growing GaAlN doped with a p-type impurity at a temperature exceeding 1000 ° C. A method for producing a group III-V compound semiconductor exhibiting good light-emitting characteristics without deteriorating a layer containing In even when grown by the method described above, and a light-emitting element exhibiting good light-emitting characteristics using the group III-V compound semiconductor To provide.

[0007]

Means for Solving the Problems The present inventors have found that a result of various investigations for 3-5 group compound semiconductor, has a specific multilayer structure and having the general formula In _x Ga _y Al _z N (here, x
+ Y + z = 1, 0 <x <1, 0 <y <1, 0 ≦ z <1)
By making the layer made of the group III-V compound semiconductor represented by the formula (3) a specific thin layer, it is possible to obtain a high-quality group III-V semiconductor crystal with few defects and grow a layer containing In. Further, the present inventors have found that by growing a GaAlN layer as a protective layer at a relatively low temperature, the heat resistance of the compound semiconductor layer is improved.

That is, the present invention relates to [1] a general formula In _x G
a _y Al _z N (where x + y + z = 1, 0 <x <1, 0
<Y <1, 0 a first layer of Group III-V compound semiconductor represented by ≦ z <1), the general formula Ga _x 'Al _y' N (provided that, x '+ y' = 1,0 < A second layer made of a Group 3-5 compound semiconductor represented by x ′ ≦ 1, 0 ≦ y ′ <1 (only
And excluding the p-type) and the general formula Ga _{x ″ A y ″} N (where x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″
3-5 in which a third layer made of a group 3-5 compound semiconductor represented by <1) is laminated in this order, and the thickness of the first layer is 5 to 90 degrees. It relates to a group III compound semiconductor.

The present invention also relates to [2] the general formula Ga _a Al _b
N (however, a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1) a fourth layer made of a Group 3-5 compound semiconductor (only
And, a except p-type), the general formula In _x Ga _y Al _z N (provided that, x + y + z = 1,0 <x <1,0 <y <1,0 ≦ z
A group 3-5 compound having a structure in which a first layer made of a group 3-5 compound semiconductor represented by <1) is laminated, and the thickness of the first layer is 5 to 90 degrees It relates to a semiconductor. In addition, the present invention relates to [3] the general formula Ga _a Al _b
N (where a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1)
On the fourth layer made of the group III-V compound semiconductor shown
In 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)
Laminating a first layer made of a Group 3-5 compound semiconductor
Wherein the thickness of the first layer is 5 mm or less.
Pertaining to Group 3-5 compound semiconductors with an upper angle of 90 ° or less
is there.

Furthermore, the present invention is [4] the general formula Ga _a A
l _b N (provided that, a + b = 1,0 ≦ a ≦ 1,0 ≦ b ≦
A fifth layer made of a Group 3-5 compound semiconductor represented by 1) and a general formula Ga _{a ′} Al _{b ′} N (where a ′ + b ′ = 1,
A fourth layer (excluding p-type ) of a Group 3-5 compound semiconductor represented by 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦ 1);
Formula In _x Ga _y Al _z N (provided that, x + y + z = 1 ,
3- represented by 0 <x <1, 0 <y <1, 0 ≦ z <1)
A first layer made of a Group V compound semiconductor, and having a structure in which the first layer has a thickness of 5 ° or more and 90 ° or more.
に The present invention relates to the following Group 3-5 compound semiconductors.
Further, the present invention relates to [5] a general formula Ga _a Al _b N (provided that
a + b = 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1) 3-
On a fifth layer made of a group V compound semiconductor, the general formula Ga
_{a ′} Al _{b ′} N (where a ′ + b ′ = 1, 0 ≦ a ′ ≦ 1,
0 ≦ b ′ ≦ 1)
A fourth layer is laminated, and a general formula In _x G is further formed thereon.
a _y Al _z N (where x + y + z = 1, 0 <x <1, 0
Group 3-5 compound semiconductor represented by <y <1, 0 ≦ z <1)
Structure obtained by laminating a first layer made of a body
And the thickness of the first layer is 5 ° or more and 90 ° or less.
It relates to a group 3-5 compound semiconductor. In addition,
Akira describes [6] the general formula Ga _{a ′} Al _{b ′} N (where a ′ +
b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦ 1) 3
A fourth layer made of a Group-V compound semiconductor, and a general formula In _x
Ga _y Al _z N (provided that, x + y + z = 1,0 <x <1,
Group 3-5 compound represented by 0 <y <1, 0 ≦ z <1)
A first layer of conductor, the general formula Ga _x 'Al _y' N (only
And x ′ + y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
A second layer made of a Group 3-5 compound semiconductor represented by
It has a structure that is laminated in this order, and the thickness of the first layer is
According to Group 3-5 compound semiconductor having a thickness of 5 ° or more and 90 ° or less
Things. Furthermore, the present invention relates to [7] the general formula Ga _{a ′} A
l _{b ′} N (where a ′ + b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦
b ′ ≦ 1)
4 of the layer, 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)
A first layer made of a group III-V compound semiconductor,
Formula Ga _x 'Al _y' N (provided that, x '+ y' = 1,0 <x '
≦ 1, 0 ≦ y ′ <1) Group 3-5 compound semiconductor
A second layer consisting of the general formula _{Ga x '' Al y ''} N ( only
X ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″
A third semiconductor made of a Group 3-5 compound semiconductor represented by <1)
And a first layer having a structure in which the first layer is laminated in this order.
Group 3-5 compound semiconductor having a thickness of 5 ° or more and 90 ° or less
It concerns the body.

The present invention, [8] the general formula Ga _a Al _b N (provided that, a + b = 1,0 ≦ a ≦ 1,0 ≦ b ≦ 1) 5 consisting of Group III-V compound semiconductor represented by And the general formula G
a _{a ′} Al _{b ′} N (where a ′ + b ′ = 1, 0 ≦ a ′ ≦
A fourth layer comprising a Group III-V compound semiconductor represented by 1,0 ≦ b '≦ 1), the general formula In _x Ga _y Al _z N (provided that, x + y + z = 1,0 <x <1,0 <Y <1, 0 ≦ z
A first layer comprising a Group III-V compound semiconductor represented by <1), the general formula Ga _x 'Al _y' N (provided that, x '+ y' =
A second layer made of a Group 3-5 compound semiconductor represented by 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1), and a general formula Ga _{x ″} Al
_{y ″} N (however, x ″ + y ″ = 1, 0 <x ″ ≦
A third layer made of a Group 3-5 compound semiconductor represented by 1, 0 ≦ y ″ <1) is laminated in this order, and the thickness of the first layer is 5 ° or more. 90 ° or less 3-
It relates to a group V compound semiconductor.

The present invention is also [9] Formula In _x Ga _y A
l _z N (where x + y + z = 1, 0 <x <1, 0 <y
<1, 0 ≦ z <1) After growing a first layer made of a Group 3-5 compound semiconductor represented by the formula Ga _{x ″} Al
_{y ″} N (however, x ″ + y ″ = 1, 0 <x ″ ≦
1, 0 ≦ y ″ <1) In the method for growing a Group 3-5 compound semiconductor, wherein the third layer made of the Group 3-5 compound semiconductor is grown at a temperature exceeding 1000 ° C. after growing a layer, prior to growing the layer of the third, the general formula Ga _x 'Al _y' N (provided that, x '+ y' = 1,0 <x '≦
The present invention relates to a method for manufacturing a Group 3-5 compound semiconductor, in which a second layer made of a Group 3-5 compound semiconductor represented by 1, 0 ≦ y ′ <1) is grown at a temperature of 1000 ° C. or less. .
Further, the present invention is [10] General formula In _x Ga _y Al _z N
(However, x + y + z = 1, 0 <x <1, 0 <y <1,
Consists of a Group 3-5 compound semiconductor represented by 0 ≦ z <1)
After growing the first layer was the general formula Ga x _{'Al y'} N (
However, x ′ + y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
A second layer made of a Group 3-5 compound semiconductor represented by
Grown at a temperature of 1000 ° C. or less, and then the general formula Ga _{x ″}
Aly _" N (where x" + y "= 1, 0 <x"
≦ 1, 0 ≦ y ″ <1) Group 3-5 compound semiconductor
Growing a third layer of body at a temperature above 1000 ° C.
3-5 compound semiconductor obtained by
It is.

The present invention relates to [ 11 ] such a 3
The present invention relates to a light-emitting element using a Group 5 compound semiconductor. Hereinafter, the present invention will be described in detail.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The Group III-V compound semiconductor of the present invention has the general formula Ga _a Al _b N (where a + b = 1, 0 ≦
a fourth layer (excluding p-type) composed of a Group 3-5 compound semiconductor represented by a ≦ 1, 0 ≦ b ≦ 1 ) and a general formula I
n _x Ga _y Al _z N (provided that, x + y + z = 1,0 <x
A first layer made of a Group 3-5 compound semiconductor represented by <1, 0 <y <1, 0 ≦ z <1), and the first layer is stacked in this order. Is characterized by a thickness of 5 ° or more and 90 ° or less. If the thickness of the first layer is smaller than 5 ° or larger than 90 °, it is not preferable that the compound semiconductor is used as a light-emitting element because the light-emitting efficiency is insufficient.

By doping the first layer with an impurity, light can be emitted at a wavelength different from the band gap of the first 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 the first
Is determined by the composition of the Group 3 element and the impurity element of the layer. In this case, in the light emitting element for display, the In concentration of the first layer is preferably 5% or more. If the In concentration is less than 5%, the emitted light is almost ultraviolet light, and it is not preferable because sufficient brightness cannot be perceived by the naked eye. The emission wavelength increases as the In concentration increases, and the emission wavelength changes from purple to blue,
Can be adjusted to green. As an impurity suitable for impurity emission, a Group 2 element is preferable. Among the group II elements, Mg,
Doping with Zn or Cd is preferable because of its high luminous efficiency. Particularly, Zn is preferable. The concentration of these elements is
It is preferably from 10 ¹⁸ to 10 ²² / cm ³ . The first layer may be simultaneously doped with Si or Ge together with these Group 2 elements. The preferred concentration range of Si and Ge is 10 ¹⁸ to 10
²² / cm ³ .

In the case of impurity emission, the emission spectrum generally becomes broad. For this reason, when high color purity is required, or when it is necessary to concentrate emission power in a narrow wavelength range, band edge emission is used. In order to realize a light-emitting element using band-edge light emission, the amount of impurities contained in the first layer must be reduced. Specifically, the concentration of each element of Si, Ge, Zn, Cd, and Mg is preferably 10 ¹⁹ / cm ³ or less, more preferably 10 ¹⁸ / cm ³ or less.

In the case of band edge emission, the emission wavelength is determined by the composition of the group III element in the first layer. When emitting light in the visible part,
The In concentration is preferably 10% or more. When the In concentration is less than 10%, the emitted light is almost ultraviolet light, and sufficient brightness cannot be perceived by the naked eye. The emission wavelength becomes longer as the In concentration increases, and the emission wavelength can be adjusted from purple to blue and green.

Although the first layer having the above structure has high quality crystallinity, thermal stability may not be sufficient. With the layer structure described below, the first layer can be grown on subsequent layers without being thermally degraded, and a light-emitting element with higher luminous efficiency can be manufactured. Namely, group III-V compound semiconductor of the present invention have the general formula In _x Ga _y Al _z
N (where x + y + z = 1, 0 <x <1, 0 <y <
A first layer comprising a Group III-V compound semiconductor represented by 1,0 ≦ z <1), the general formula Ga _x 'Al _y' N (provided that, x '
+ Y '= 1,0 <x' ≦ 1,0 ≦ y ' consists 3-5 group compound semiconductor represented by <1) the second layer (Here, p-type
) And the general formula Ga _{x ″} Al _{y ″} N (where x ″
+ Y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <1) and a third layer made of a Group 3-5 compound semiconductor, which is stacked in this order. The thickness of the first layer is not less than 5 ° and not more than 90 °. The thickness of the first layer is preferably from 10 ° to 80 °.

The thickness of the second layer is preferably not less than 50 ° and not more than 1 μm. More preferably, it is 70 ° or more and 5000 ° or less. When the layer thickness is smaller than 50 °, the heat resistance of the first layer is not sufficient, and deterioration occurs during the formation of the third layer.
If it is larger than μm, it is not preferable because a sufficient emission intensity cannot be obtained when the device is finally formed.

The Al concentration (x ″) of the second layer is preferably 0.05 ≦ x ″ from the viewpoint of thermal stability of the active layer. However, the electrical resistance tends to increase as the Al concentration increases, and x ″ ≦ 0.5 is preferable as a range in which the electrical resistance of the element does not particularly increase. A more preferable range of the Al concentration is 0.1 ≦ x ″ ≦ 0.45. The second layer is preferably p-type from the viewpoint of electrical characteristics. In order for the second layer to exhibit p-type, it is necessary to dope the acceptor impurity at a high concentration. As acceptor-type impurities,
Specific examples include Group 2 elements. Of these,
Mg and Zn are preferred, and Mg is more preferred. However, in order for the second layer to exhibit p-type conduction, it is preferable that the second layer is doped with a high concentration of acceptor-type impurity of about 10 ²⁰ / cm ³ or more. In the case where contains a high concentration of impurities, the crystallinity may be lowered and the characteristics as an element may be deteriorated. In such a case, it is necessary to lower the impurity concentration. The range of the impurity concentration that does not lower the crystallinity is preferably 10 ¹⁹
/ Cm ³ or less, more preferably 10 ¹⁸ / cm ³ or less.

The resistance of the uppermost p-type layer may be further reduced by annealing after growth. The p-type third layer, the second layer, and the first layer are partially removed by etching to expose the n-type layer, an n-electrode is provided on the exposed portion, and the p-type third layer is removed. By providing a p-electrode directly on the layer to form a light-emitting element and passing a current through these electrodes in the forward direction, desired light emission can be obtained. First
Is the same as that described above.

FIGS. 1 and 2 show examples of the structure of a light emitting device using a Group 3-5 compound semiconductor of the present invention. FIG. 1 shows that a first layer is grown on a fifth layer, a second layer having a larger band gap than the first layer is grown on the first layer, and a fifth layer is grown on the first layer. This is an example in which a third layer having a conductivity different from that of the third layer is grown. The electrodes are formed in a fifth layer and a third layer. When a voltage is applied to the two electrodes, a current flows and light is emitted in the first layer. FIG. 2 shows the second layer having conductivity different from that of the fifth layer. As in the example of FIG. 1, light is emitted by applying a voltage. In general, the fifth layer is of n-type and the third layer is of p-type in the example of FIG. 1 for ease of crystal growth. In the example of FIG. 2 without a third layer, the second layer is p-type.

Here, the n-type fifth layer may be deteriorated in crystallinity due to high concentration of impurities. In such a case, if the n-type fifth layer is in direct contact with the first layer, luminous efficiency and electrical characteristics may be reduced. Therefore, such a problem may be sometimes reduced by providing a fourth layer having a low impurity concentration between the n-type fifth layer and the first layer. This example is shown in FIG.

That is, the Group III-V compound semiconductor of the present invention has the general formula Ga _a Al _b N (where a + b = 1, 0 ≦
a ≦ 1, 0 ≦ b ≦ 1), a fifth layer made of a Group III-V compound semiconductor, and a general formula Ga _{a ′} Al _{b ′} N (provided that the impurity concentration is lower than that of the fifth layer) a '+ b' = 1, 0
A fourth layer comprising a Group III-V compound semiconductor represented by ≦ a '≦ 1,0 ≦ b' ≦ 1), the general formula In _x Ga _y Al _z
N (where x + y + z = 1, 0 <x <1, 0 <y <
1, 0 ≦ z <1) and a first layer made of a Group 3-5 compound semiconductor, which is laminated in this order,
In the case where Si is used as the n-type impurity, wherein the thickness of the first layer is 5 ° or more and 90 ° or less, the preferable concentration of Si in the fourth layer having a low impurity concentration is 1%.
0 ¹⁸ / cm ³ , more preferably 10 ¹⁷ / cm ³ or less. Further, the preferable range of the layer thickness is 10 ° or more and 1 µm or less, more preferably 20 ° or more and 5000 ° or less. If the layer thickness is less than 10 °, the effect is not sufficient, and if it is more than 1 μm, the electrical characteristics are undesirably deteriorated.

A group III-V compound semiconductor which can provide a light-emitting element having higher luminous efficiency by combining the above-described laminated structures of the group III-V compound semiconductors of the present invention is given. That is, the Group 3-5 compound semiconductor of the present invention has the general formula Ga _a Al _b N (where a + b = 1, 0 ≦
a ≦ 1, 0 ≦ b ≦ 1), a fifth layer made of a Group III-V compound semiconductor, and a general formula Ga _{a ′} Al _{b ′} N (provided that the impurity concentration is lower than that of the fifth layer) a '+ b' = 1, 0
A fourth layer comprising a Group III-V compound semiconductor represented by ≦ a '≦ 1,0 ≦ b' ≦ 1), the general formula In _x Ga _y Al _z
N (where x + y + z = 1, 0 <x <1, 0 <y <
A first layer comprising a Group III-V compound semiconductor represented by 1,0 ≦ z <1), the general formula Ga _x 'Al _y' N (provided that, x '
+ Y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1), a second layer made of a Group 3-5 compound semiconductor represented by general formula Ga
_{x "} Aly _" N (where x "+ y" = 1, 0 <x "≤
A third layer made of a Group 3-5 compound semiconductor represented by 1, 0 ≦ y ″ <1) is laminated in this order, and the thickness of the first layer is 5 ° or more. 90 ° or less. By using the group III-V compound semiconductor composed of at least five layers, a light-emitting element having excellent luminous efficiency can be obtained. FIG. 3 illustrates an example of a stacked structure of the light-emitting element. Note that in the example of the light-emitting element shown in FIGS. 1, 2, and 3, the light-emitting layer is a single layer, but the layer functioning as the light-emitting layer may have a stacked structure of a plurality of layers. As a specific stacked structure that functions as a light-emitting layer, a so-called multiple quantum well structure in which a plurality of light-emitting layers are stacked with a layer having a larger band gap is used. 3- of the present invention
Si, SiC, sapphire, or the like can be used as the substrate for the group V compound semiconductor. When using such a substrate, AlN with first low temperature on a substrate, GaN or the general formula Ga _s Al _t N, (provided that, s + t = 1,0 <s <1,
A compound semiconductor represented by 0 <t <1) or a laminated structure thereof is grown as a buffer layer.
By growing a Group 5 compound semiconductor, the compound semiconductor having high crystallinity can be grown. Note that in the semiconductor of the present invention, in order to efficiently confine charges in the first layer, it is preferable that the band gap of the two layers in contact with the first layer be 0.1 eV or more larger than that of the first layer. More preferably, it is 0.3 eV or more.

The method for producing a Group 3-5 compound semiconductor according to the present invention includes a molecular beam epitaxy (hereinafter sometimes referred to as MBE) method, a metal organic chemical vapor deposition (hereinafter referred to as MOVPE).
It may be written. ), Hydride vapor phase epitaxy (hereinafter sometimes referred to as HVPE), and the like. When the MBE method is used, the nitrogen source is
A gas source molecular beam epitaxy (hereinafter, sometimes referred to as GSMBE) method, which is a method of supplying nitrogen gas, ammonia, and other nitrogen compounds in a gaseous state, is generally used. In this case, the nitrogen source may be chemically inert, and the nitrogen atoms may not be easily incorporated into the crystal. In that case, the nitrogen raw material is excited by a microwave or the like and is supplied in an activated state, whereby the nitrogen taking-in efficiency can be increased.

In the case of the MOVPE method, the following raw materials can be used. As a raw material of the group 3 element, trimethylgallium [(CH ₃ ) ₃ Ga, hereinafter sometimes referred to as TMG. ], Triethyl gallium [(C ₂ H _{5) 3} G
a, may be referred to as TEG hereinafter. General formula R ₁ R
Trialkylgallium represented by ₂ R ₃ Ga (where R ₁ , R ₂ and R ₃ represent lower alkyl groups); triethylaluminum [(C ₂ H ₅ ) ₃ Al, hereinafter referred to as TEA. is there. ], Triisobutylaluminum [i
_{- (C 4 H 9) 3} Al, sometimes hereinafter referred to as TEA. ] Or other general formulas R ₁ R ₂ R ₃ Al (where R ₁ , R
₂ and R ₃ have the same definition as above. ), Trimethylindium [(CH ₃ ) ₃ In, hereinafter sometimes referred to as TMI. ], Triethylindium [(C ₂ H ₅ ) ₃ In]
R ₁ R ₂ R ₃ In (where R ₁ , R ₂ , R
₃ is the same definition as above. And the like. These may be used alone or as a mixture.

Next, as Group V raw materials, ammonia, hydrazine, methylhydrazine, 1,1-dimethylhydrazine, 1,2-dimethylhydrazine, t-butylamine, ethylenediamine and the like can be mentioned. These may be used alone or as a mixture. Of these raw materials, ammonia and hydrazine do not contain carbon atoms in the molecule,
It is preferable because carbon contamination in the semiconductor is small. MOVP
When growing the group 3-5 compound semiconductor of the present invention by the E method,
The growth pressure is preferably 1 atm or less and 0.001 atm or more.
When the growth pressure is higher than 1 atm, the use efficiency of the raw material may be low and the uniformity of the thickness of the grown film may be reduced.
As the growth pressure is lowered, the uniformity of the film thickness is improved. However, even if the pressure is less than 0.001 atm, the effect of improving the uniformity is not so effective, and the crystallinity may be rather reduced. A more preferable range of the growth pressure is 1 atm.
Atmospheric pressure or higher.

[0029] In particular the following general formula In _x Ga _y Al _z N
(However, x + y + z = 1, 0 <x <1, 0 <y <1,
After growing a first layer made of a Group 3-5 compound semiconductor represented by 0 ≦ z <1), the general formula Ga _{x ″ A y ″} N
(However, x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <
A method for growing a group III-V compound semiconductor in which the third layer made of a group III-V compound semiconductor represented by 1) is grown at a temperature exceeding 1000 ° C will be described. Group 3-5 manufacturing method of the compound semiconductor of the present invention, after growing the first layer, prior to growing the third layer, the general formula Ga x _{'Al y'} N (provided that, x '+ y' = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
It is characterized by growing at a temperature of 000 ° C. or less. M
When the film is formed by the OVPE method, the growth of the second and third layers is preferably performed in an atmosphere containing no hydrogen. When grown in an atmosphere containing hydrogen, the first layer is deteriorated, and an element having good characteristics cannot be manufactured.

Here, the growth temperature of the second layer is 1
000 ° C or lower, and preferably 400 ° C or higher and 1000 ° C or lower. More preferably at least 500 ° C. and 90
0 ° C. or less. If the film formation temperature is too high, the first layer which is the active layer is deteriorated during the formation of the second layer, and when the light emitting element is finally formed, it is expected from the composition of each element in the active layer. However, problems such as a lack of a luminescent color and insufficient luminous intensity occur. On the other hand, if the film forming temperature is too low, the film forming rate becomes low, which is not practical.

In the method of manufacturing a Group 3-5 compound semiconductor, it is preferable that the thickness of the first layer is 5 ° to 500 °. In particular, when used as a light-emitting element having high emission intensity, the angle is preferably 5 ° or more and 90 ° or less. When the film thickness is smaller than 5 ° or larger than 500 °, the light emitting element using the compound semiconductor is not preferable because the luminous efficiency is insufficient.

[0032]

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 light emitting device having a structure shown in FIG. 3 was manufactured. Hereinafter, description will be given based on FIG. Here, the group 3-5 compound semiconductor layer is
Fabricated by metalorganic vapor phase epitaxy. Note that silane (SiH ₄ ) diluted with nitrogen was used to dope Si as an n-type dopant, and biscyclopentadienyl magnesium [(C ₅ H ₅ ) ₂ Mg was used to dope Mg as a p-type dopant. , Hereinafter referred to as Cp ₂ Mg. ] Was used. As the substrate, sapphire C-plane 9 was mirror-polished and used after organic cleaning. First, hydrogen is used as a carrier gas, and hydrogen chloride gas is supplied at 1100 ° C.
The reactor and the substrate were cleaned. After completion of the cleaning, at a substrate temperature of 550 ° C., TMG and ammonia were supplied to form a GaN buffer layer 8 having a thickness of 500 °. Next, the substrate temperature is raised to 1100 ° C., and TMG, ammonia, and silane gas are supplied, and the Si-doped n-type carrier concentration is 1 × 10 ¹⁹ / cm ³ and the film thickness is about 3 μm.
Was grown, and a non-doped GaN layer 4 was grown at the same temperature at 1500 °. The deposition rates of the Si-doped layer and the non-doped layer were 1000 ° / min.
00 ° / min.

Next, the substrate temperature was lowered to 785 ° C., the carrier gas was changed to nitrogen, and TEG, TMI and ammonia were changed to 0.04 sccm, 0.08 sccm and 4 sl, respectively.
m, and the In _0.3 Ga _0.7 N layer 1 as the light emitting layer is
Grow for 0 seconds. Furthermore, at the same temperature, TEG, TEA
And ammonia at 0.032 sccm and 0.032 sccm, respectively.
08 sccm and 4 slm to supply Ga as a protective layer.
_{A 0.8} Al _0.2 N layer 2 was grown for 10 minutes. Where sl
m 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, and 1000 sccm indicates 1 gas.
slm. In addition, regarding the layer thickness of these two layers,
Since 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, the layer thicknesses obtained from the above growth times are 50 ° and 300 °, respectively.
Can be calculated.

Next, the substrate temperature is increased to 1100 ° C.
After supplying p ₂ Mg and ammonia and performing an air-flow process for 40 seconds, TMG, Cp ₂ Mg and ammonia were supplied, and the Mg-doped GaN layer 3 was cooled to 5,000.
ÅI grew up. After removing the Group 3-5 compound semiconductor sample prepared above from the reaction furnace, the sample was placed at 800 ° C. in nitrogen.
Annealing treatment was performed for 20 minutes to turn the Mg-doped GaN layer into a low-resistance p-type layer. An electrode was formed on the thus obtained sample by a conventional method to obtain an LED. Ni-A as p electrode
Al was used as a u alloy and an n electrode. When a current was applied to this LED in the forward direction, it emitted a clear blue light with an emission wavelength of 4570 °. The luminance at 20 mA was 1200 mcd.

Example 2 A light emitting device having the structure shown in FIG. 1 was manufactured. Hereinafter, description will be given based on FIG. Gallium nitride based semiconductor is MOVPE
It was produced by vapor phase growth by the method. The substrate used was a mirror-polished sapphire C surface which was organically washed and used. For growth, first, the substrate was heated to 1100 ° C. in hydrogen, and in this state, the reaction furnace, the susceptor and the substrate were vapor-phase etched with HCl gas. After stopping the HCl gas, the substrate was further cleaned at 1100 ° C. in hydrogen. Next, after forming a GaN film at 500 ° C. as a buffer layer using TMG and ammonia at 600 ° C., the TMG, ammonia and silane (SiH ₄ ) as a dopant were used to form a GaN film.
At 100 ° C., a GaN layer 5 doped with Si was formed with a thickness of 3 μm.

After the temperature was lowered to 800 ° C., the carrier gas was changed from hydrogen to nitrogen, and the T 0.1, TMI, and TEA were used to deposit the In _0.17 Ga _0.83 N layer 1 at 60 ° and Ga _0.8 Al
_A 0.2N layer 2 was grown at 300 °. Next, raise the temperature to 110
The temperature was raised to 0 ° C., and TMG, ammonia, and bismethylcyclopentadienyl magnesium [(CH ₃ C ₅ H ₄ ) ₂ Mg as a dopant, sometimes referred to as MCp ₂ Mg hereinafter. And a GaN layer 3 doped with Mg was grown at 5000 °. After completion of the growth, the substrate was taken out and heat-treated at 800 ° C. in nitrogen. An electrode was formed on the thus obtained sample according to a conventional method to obtain an LED. Ni-Au alloy as p electrode, Al as n electrode
Was used. When a current of 20 mA was applied to this LED in the forward direction, a clear blue light was emitted and the luminance was 120 mcd.
Met.

Comparative Example 1 An LED was manufactured in the same manner as in Example 2 except that the thickness of the InGaN layer was changed to 100 °, and the same evaluation as in Example 2 was carried out. Although light was emitted, the luminance was less than 10 mcd in most parts.

Example 3 The thickness of the first layer which is the light emitting layer was 21 °, 32 °, 86 °.
A Group 3-5 compound semiconductor sample was produced in the same manner as in Example 1 except that When an LED was formed by forming electrodes in the same manner as in Example 1, when a forward current was passed, all the samples showed clear blue light emission, and the luminance at 20 mA was 20 mcd or more. The thickness of the first layer and 20 mA
FIG. 4 shows the relationship between the external quantum efficiencies at.

Comparative Example 2 A Group 3-5 compound semiconductor sample was prepared in the same manner as in Example 1 except that the thickness of the first layer, which was the light emitting layer, was 150 °. An electrode is formed in the same manner as in Example 1 and LE
When a forward current was applied as D, light emission was only slightly pale. The luminance at 20 mA was 1 in Example 1.
It was less than 1/1000.

Examples 4, 5, and 6 The samples shown in FIG. 5 were produced according to the method described below. First, a non-doped GaN layer 5 as a fifth layer is grown at 1100 ° C. by 3 μm, and a non-doped InGaN layer 1 as a first layer is grown by 50 ° in a range of 785 ° C. to 825 ° C.
At the same temperature as the first layer, the non-doped Ga
An AlN layer 2 was grown. After growth, the first layer, InG
A heat treatment was performed to confirm the thermal stability of the aN layer 1, and a photoluminescence spectrum (hereinafter, sometimes referred to as a PL spectrum) from the InGaN layer 1 before and after the heat treatment was measured.

Table 1 summarizes the growth conditions, heat treatment conditions, and changes in the peak intensity of the PL spectrum before and after the heat treatment of the sample manufactured in this example. Table 1 shows that the intensity of the PL spectrum hardly changed in any of the samples due to the heat treatment, indicating that the second layer of the present invention is important for the thermal stability of the first layer.

[0042]

[Table 1] 1) Heat treatment conditions: 1100 ° C. for 10 minutes in a mixed gas atmosphere of the same volume of nitrogen and ammonia. 2) Percentage decrease in PL spectrum intensity after heat treatment compared to before heat treatment

[0043]

The group III-V compound semiconductor of the present invention has high quality with few defects and can provide a light emitting device having high luminous efficiency and good luminous characteristics. After growing a layer containing In by the method of manufacturing a Group 3-5 compound semiconductor of the present invention, p-type GaAs is grown.
Even if 1N is grown at a temperature exceeding 1000 ° C., the active layer is not deteriorated, and a high-quality Group 3-5 compound semiconductor with few defects can be obtained.

[Brief description of the drawings]

FIG. 1 illustrates a structure of a light-emitting element of the present invention (a view illustrating a structure of a light-emitting element manufactured in Example 2).

FIG. 2 illustrates a structure of a light-emitting element of the present invention.

FIG. 3 is a diagram illustrating a structure of a light-emitting element of the present invention (a diagram illustrating a structure of a light-emitting element manufactured in Example 1).

FIG. 4 is a graph showing the relationship between the thickness of the first layer and the external quantum efficiency at 20 mA in the LED manufactured in the example (however,
The first layer having a thickness of 50 ° corresponds to the first embodiment, and the other layers correspond to the third embodiment. ).

FIG. 5 is a diagram illustrating a configuration of a Group 3-5 compound semiconductor manufactured in Examples 4, 5, and 6;

[Explanation of symbols]

1. . . Formula In _x Ga _y Al _z N (provided that, x + y
1. a first layer made of a Group 3-5 compound semiconductor represented by + z = 1, 0 <x <1, 0 <y <1, 0 ≦ z <1) . . General formula Ga _{x ′ A y ′} N (where x ′ + y ′ =
2. a second layer made of a Group 3-5 compound semiconductor represented by 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1) . . General formula Ga _{x ″ A y ″} N (where x ″ +
3 represented by y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <1)
3. a third layer made of a Group V compound semiconductor; . . The general formula Ga _{a ′} Al _{b ′} N (where a ′ + b ′ =
4. a fourth layer made of a Group 3-5 compound semiconductor represented by 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦ 1) . . General formula Ga _a Al _b N (where a + b = 1,
5. A fifth layer made of a Group 3-5 compound semiconductor represented by 0 ≦ a ≦ 1, 0 ≦ b ≦ 1) Si-doped n-type GaN layer . . p electrode 7. . . 7. n-electrode . . Buffer layer 9. . . Sapphire substrate

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-8-316528 (JP, A) JP-A-7-78671 (JP, A) JP-A-7-205954 (JP, A) JP-A-8-786 15228 (JP, A) JP-A-7-302770 (JP, A) JP-A-7-249797 (JP, A) JP-A-6-21511 (JP, A) JP-A-6-26068 (JP, A) JP-A-6-268257 (JP, A) Jpn. J. Appl. Phys. Vol. 34, Part 2, No. 7A (1995-July), pp. 7-26. L797-799 Jpn. J. Appl. Phys. Vol. 34, Part 2, No. 10B (1995-October), pp. L 1332-1335 Appl. Phys. Lett, Vol. 67, no. 13 (1995-Septem ber), pp. 139-143. 1868-1870 (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 29/43 H01L 21/205 H01L 21/28 H01L 33/00

Claims (14)

(57) [Claims] 1. A general formula In _x Ga _y Al _z N (provided that, x +
y + z = 1,0 <x < 1,0 <y < a first layer of Group III-V compound semiconductor represented by 1,0 ≦ z <1), the general formula Ga _x 'Al _y' N ( However, x ′ + y ′ = 1, 0 <
a second layer (excluding p-type ) of a Group III-V compound semiconductor represented by x ′ ≦ 1, 0 ≦ y ′ <1 ) and a general formula Ga _{x ″ A y ″} N ( Where x ″ + y ″ = 1, 0
And a third layer made of a Group 3-5 compound semiconductor represented by <x ″ ≦ 1, 0 ≦ y ″ <1). 3-5 compound semiconductor characterized by having a thickness of 5 ° or more and 90 ° or less. 2. The general formula Ga _a Al _b N (where a + b =
A fourth layer (excluding p-type ) of a Group 3-5 compound semiconductor represented by 1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1);
Formula In _x Ga _y Al _z N (provided that, x + y + z = 1 ,
3- represented by 0 <x <1, 0 <y <1, 0 ≦ z <1)
A Group 3-5 compound semiconductor, having a structure in which a first layer made of a Group 5 compound semiconductor is stacked, wherein the thickness of the first layer is 5 ° or more and 90 ° or less. 3. The general formula Ga _a Al _b N (where a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1) group 3-5 compound
On the fourth layer of SEMICONDUCTOR general formula In _x Ga _y A
l _z N (where x + y + z = 1, 0 <x <1, 0 <y
<1, 0 ≦ z <1) Group 3-5 compound semiconductor
Having a structure obtained by laminating a first layer comprising
And the thickness of the first layer is not less than 5 ° and not more than 90 °
3-5 compound semiconductor characterized by the above-mentioned. 4. The general formula Ga _a Al _b N (where a + b =
1, 0 ≦ a ≦ 1, 0 and a fifth layer comprising a Group III-V compound semiconductor represented by ≦ b ≦ 1), one general formula Ga _a 'Al _b' N
(However, a ′ + b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦
Fourth layer made of a Group 3-5 compound semiconductor represented by 1)
(Excluding p-type) and the general formula In _x Ga _y Al _z N
(However, x + y + z = 1, 0 <x <1, 0 <y <1,
A first layer made of a Group 3-5 compound semiconductor represented by 0 ≦ z <1) and laminated in this order, and the thickness of the first layer is 5 ° or more and 90 ° or less. A Group 3-5 compound semiconductor, comprising: 5. The general formula Ga _a Al _b N (where a + b =
1, 0 ≦ a ≦ 1, 0 ≦ b ≦ 1) group 3-5 compound
On the fifth layer made of an oxide semiconductor, the general formula Ga _{a ′} Al _{b ′}
N (however, a ′ + b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′
≦ 1) a fourth group consisting of a Group 3-5 compound semiconductor
Laminating layer, further thereon, the general formula In _x Ga _y Al _z
N (where x + y + z = 1, 0 <x <1, 0 <y <
From the group III-V compound semiconductor represented by 1, 0 ≦ z <1)
Having a structure obtained by laminating a first layer
And the thickness of the first layer is not less than 5 ° and not more than 90 °
3-5 compound semiconductor characterized by the above-mentioned. 6. The general formula Ga _{a ′} Al _{b ′} N (where a ′ +
b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦ 1) 3
A fourth layer made of a Group-V compound semiconductor, and a general formula In _x
Ga _y Al _z N (provided that, x + y + z = 1,0 <x <1,
Group 3-5 compound represented by 0 <y <1, 0 ≦ z <1)
A first layer of conductor, the general formula Ga _x 'Al _y' N (only
And x ′ + y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
A second layer made of a Group 3-5 compound semiconductor represented by
It has a structure that is laminated in this order, and the thickness of the first layer is
Group 3-5 characterized by being at least 5 ° and at most 90 °
Compound semiconductor. 7. The formula Ga _{a ′} Al _{b ′} N (where a ′ +
b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦ 1) 3
A fourth layer made of a Group-V compound semiconductor, and a general formula In _x
Ga _y Al _z N (provided that, x + y + z = 1,0 <x <1,
Group 3-5 compound represented by 0 <y <1, 0 ≦ z <1)
A first layer of conductor, the general formula Ga _x 'Al _y' N (only
And x ′ + y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
A second layer comprising a Group 3-5 compound semiconductor represented by
General formula _{Ga x '' Al y ''} N ( provided that, x '' + y '' = 1,
Group 3-5 represented by 0 <x ″ ≦ 1, 0 ≦ y ″ <1)
A third layer made of a compound semiconductor is laminated in this order
Having a thickness of 5 to 90 mm
A group 3-5 compound semiconductor, characterized in that: 8. The general formula Ga _a Al _b N (where a + b =
1, 0 ≦ a ≦ 1, 0 and a fifth layer comprising a Group III-V compound semiconductor represented by ≦ b ≦ 1), one general formula Ga _a 'Al _b' N
(However, a ′ + b ′ = 1, 0 ≦ a ′ ≦ 1, 0 ≦ b ′ ≦
A fourth layer comprising a Group III-V compound semiconductor represented by 1), the general formula In _x Ga _y Al _z N (provided that, x + y + z =
A first layer made of a Group 3-5 compound semiconductor represented by 1, 0 <x <1, 0 <y <1, 0 ≦ z <1);
_{x ′} Al _{y ′} N (where x ′ + y ′ = 1, 0 <x ′ ≦ 1,
A second layer made of a group 3-5 compound semiconductor represented by 0 ≦ y ′ <1) and a general formula Ga _{x ″ A y ″} N (where,
x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <
And a third layer made of a group 3-5 compound semiconductor represented by 1) having a structure laminated in this order, wherein the thickness of the first layer is 5 to 90 degrees. Do 3-
Group 5 compound semiconductor. 9. formula Ga _x 'Al _y' N (provided that, x '+
3 represented by y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
Claim thickness of the second layer consisting of-V compound semiconductor is characterized in that at 50Å or 1μm or less 1, 6, 7
Or a group 3-5 compound semiconductor according to item 8 . 10. A general formula In _x Ga _y Al _z N (here, x
+ Y + z = 1, 0 <x <1, 0 <y <1, 0 ≦ z <1)
Wherein the concentration of each element of Si, Ge, Zn, Cd and Mg contained in the first layer made of a group 3-5 compound semiconductor is 1 × 10 ¹⁹ / cm ³ or less. 3-5 group compound semiconductor according to any one of claims 1-9 for. 11. A general formula Ga _x 'Al _y' N (provided that, x '+
3 represented by y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
3-5 group compound semiconductor according to claim 1, 6, 7 or 8, wherein the concentration of Mg contained in the second layer of-V compound semiconductor is 10 ¹⁹ / cm ³ or less. 12. A general formula In _x Ga _y Al _z N (here, x
+ Y + z = 1, 0 <x <1, 0 <y <1, 0 ≦ z <1)
After growing a first layer made of a group III-V compound semiconductor represented by the following formula, Ga _{x ″ A y ″} N (where,
x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦ y ″ <
In the method for growing a Group 3-5 compound semiconductor, wherein the third layer made of a Group 3-5 compound semiconductor represented by 1) is grown at a temperature exceeding 1000 ° C., after growing the first layer,
Before growing the said third layer, the general formula Ga x _{'Al y'} N
(However, x ′ + y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <
A method for producing a Group 3-5 compound semiconductor, comprising: growing a second layer made of a Group 3-5 compound semiconductor represented by 1) at a temperature of 1000 ° C. or less. 13. general formula In _x Ga _y Al _z N (here, x
+ Y + z = 1, 0 <x <1, 0 <y <1, 0 ≦ z <1)
Forming a first layer made of a group 3-5 compound semiconductor represented by
After it was allowed length, the general formula Ga _x 'Al _y' N (provided that, x '+
3 represented by y ′ = 1, 0 <x ′ ≦ 1, 0 ≦ y ′ <1)
The second layer made of a Group -5 compound semiconductor is heated to 1000 ° C. or lower.
Grown at a temperature below, was then general formula _{Ga x '' Al y ''} N (
However, x ″ + y ″ = 1, 0 <x ″ ≦ 1, 0 ≦
Consists of a Group 3-5 compound semiconductor represented by y ″ <1)
Growing the third layer at a temperature above 1000 ° C.
A Group 3-5 compound semiconductor, which is obtained from the above. 14. any of claims 1 to 11, or 13
A light emitting device using the group 3-5 compound semiconductor according to item 1.