JP2681733B2 - Nitrogen-3 group element compound semiconductor 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 blue-emitting nitrogen-group III compound semiconductor light emitting device.

[0002]

2. Description of the Related Art Conventionally, a blue light emitting diode using a GaN-based compound semiconductor has been known. The GaN
Attention has been paid to the fact that system compound semiconductors are of direct transition type and thus have high luminous efficiency, and that blue, one of the three primary colors of light, is used as the luminescent color.

Recently, GaN light emitting diodes have
It became clear that p-type GaN can be obtained by adding Mg and irradiating an electron beam. As a result, a pn junction is provided instead of the conventional junction between the n-layer and the semi-insulating layer (i-layer).
GaN light emitting diodes have been proposed. The electrode of this light emitting diode has an n-layer of aluminum (Al) and a p-layer of gold (A
u).

[0004]

However, even with the above-mentioned light emitting diode having a pn junction, the light emission luminance is not yet sufficient, and the driving voltage is high. Accordingly, an object of the present invention is to provide a nitrogen-group III element compound semiconductor (Al _x Ga _Y In _1-XY
N; X = 0, Y = 0, and X = Y = 0) The purpose is to improve the light emission luminance of the light emitting diode and to lower the driving voltage.

[0005]

A first feature of the present invention is as follows.
n-type nitrogen-group III element compound semiconductor (Al _x Ga _Y In _1-XY N; X =
0, Y = 0, X = Y = 0) and p-type nitrogen-3
Group element compound semiconductor; in nitrogen -3-group element compound semiconductor light-emitting device having a p layer formed of _{(Al x Ga Y In 1-} XY N X = 0, Y = 0, X = Y = a containing 0), p The layer has a hole concentration of 1 × 10 ¹⁶
/ cm ³ or higher high carrier concentration p ⁺ layer and its high carrier concentration
With a low carrier concentration p layer having a lower hole concentration than the p ⁺ layer
Electrode composed of double layers and joined to high carrier concentration p ⁺ layer
Is nickel (Ni) .

The second characteristic is that the p layer is made of magnesium (Mg).
It has been added . The third feature is that the low carrier concentration p-layer has a hole concentration of 1 ×
10 ¹⁴ is that it is ~1 × 10 ¹⁶ / cm ^3. The fourth characteristic is that the high carrier concentration p ⁺ layer is 0.1 to 0.5.
It has a thickness of μm. The fifth characteristic is that the low carrier concentration p-layer is 0.2 to 1.0 μm.
m. The sixth feature is that the electrode joined to the high carrier concentration p ⁺ layer and the electrode joined to the n layer are formed on the same surface side. The seventh characteristic is a low carrier concentration p layer and a high carrier concentration.
The p ⁺ layer is formed by making a part of the semi-insulating nitrogen-group 3 element compound semiconductor layer into p-type.

[0007]

INDUSTRIAL APPLICABILITY The present invention provides a nitrogen-group III element compound semiconductor (Al _x Ga _Y In _1-XY N; X = 0, Y = having a p-layer and an n-layer).
0, the X = including Y = 0) light-emitting device, the p-layer, the hole concentration
With a high carrier concentration p ⁺ layer of 1 × 10 ¹⁶ / cm ³ or more, and
High carrier concentration Low carrier with lower hole concentration than p ⁺ layer
Consists of a double layer consisting of a high concentration p layer and a high carrier concentration p ⁺ layer
The bonding electrodes by a nickel (Ni), good
A favorable ohmic property was obtained and the driving voltage was lowered.
Moreover, the injection current can be increased at the same voltage due to the decrease in the driving voltage, and the emission brightness is improved.

Further , the hole concentration of the low carrier concentration p layer is set to 1 ×.
The luminous efficiency is improved by setting 10 ¹⁴ to 1 × 10 ¹⁶ / cm ^3.
Can be done. Furthermore, the high carrier concentration p ⁺ layer
By setting the thickness to 0.1 to 0.5 μm, the series resistance can be reduced.
The hole injection efficiency can be improved. Sa
Luo, 0.2~1.0μ m thickness low carrier concentration p layer
By lowering the series resistance and improving the luminous efficiency
Can be

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment In FIG. 1, a light emitting diode 10 has a sapphire substrate 1 on which 500 .ANG.
Buffer layer 2 is formed. On the buffer layer 2, a film thickness of about 2.2 μm and an electron concentration of 2 × 10 ¹⁸ / cm ³
A high carrier concentration n ⁺ layer 3 composed of silicon-doped GaN,
A low carrier concentration n layer 4 of undoped GaN having a film thickness of about 1.5 μm and an electron concentration of 1 × 10 ¹⁶ / cm ³ is formed. Furthermore,
On the low carrier concentration n-layer 4, the film thickness is about 0.5 μm in order.
m, hole concentration 1 × 10 ¹⁶ / cm ³ magnesium (Mg) -doped GaN
And a high carrier concentration p ⁺ layer 52 having a hole concentration of 2 × 10 ¹⁷ / cm ³ is formed. The electrode 7 made of nickel connected to the high carrier concentration p ⁺ layer 52 and the high carrier concentration n ⁺
An electrode 8 made of nickel and connected to the layer 3 is formed. The electrode 8 and the electrode 7 are electrically insulated and separated by the groove 9.

Next, a method of manufacturing the light emitting diode 10 having this structure will be described. The light emitting diode 10 includes:
It was manufactured by vapor phase growth by an organometallic compound vapor phase growth method (hereinafter referred to as “M0VPE”). The gas used was NH
₃ and the carrier gas H ₂ and trimethylgallium (Ga (CH _{3) 3)}
(Hereinafter referred to as "TMG") and trimethylaluminum (Al
(CH ₃ ) ₃ ) (hereinafter referred to as “TMA”), silane (SiH ₄ ), and biscyclopentadienyl magnesium (Mg (C ₅ H ₅ ) ₂ ) (hereinafter referred to as “CP ₂ Mg”).

First, the single crystal sapphire substrate 1 having the a-plane as the main surface, which has been cleaned by organic cleaning and heat treatment, is mounted on a susceptor placed in the reaction chamber of the M0VPE apparatus. Next, while flowing H ₂ at normal pressure into the reaction chamber at a flow rate of 2 liter / min, the temperature was 1100
The sapphire substrate 1 was subjected to gas-phase etching at a temperature of ℃.

Next, the temperature is lowered to 400 ° C. and H ₂ is added.
20 liter / min, NH ₃ 10 liter / min, TMA 1.8 × 10 ^-5
Supplying at mol / min, an AlN buffer layer 2 was formed to a thickness of about 500 °. Next, the temperature of the sapphire substrate 1 was set to 1150
° C, H ₂ at 20 liter / min, NH ₃ at 10 liter / min,
TMG 1.7 × 10 ^-4 mol / min, supplying 30 minutes silane diluted with H ₂ to 0.86ppm a (SiH ₄₎ at a rate of 200 Milliliter / min, a film thickness of about 2.2 .mu.m, electron concentration 2 × 10 ¹⁸ / A high carrier concentration n ⁺ layer 3 made of GaN of cm ³ was formed.

Then, the temperature of the sapphire substrate 1 is set to 1150 ° C.
, H ₂ at 20 liter / min, NH ₃ at 10 liter / min, TMG
At a rate of 1.7 × 10 ^-4 mol / min for 20 minutes,
A low carrier concentration n-layer 4 made of GaN having a thickness of 1.5 μm and an electron concentration of 1 × 10 ¹⁶ / cm ³ was formed.

Next, the sapphire substrate 1 is kept at 1150 ° C., H ₂ is 20 liter / min, NH ₃ is 10 liter / min, and TMG is
1.7 × 10 ⁻⁴ mol / min and CP ₂ Mg were supplied at a rate of 2 × 10 ⁻⁷ mol / min for 7 minutes to form a 0.5 μm-thick low carrier concentration p-layer 51 made of GaN. In this state, the low carrier concentration p layer 51 is still an insulator having a resistivity of 10 ⁸ Ωcm or more.

Next, while keeping the sapphire substrate 1 at 1150 ° C., H ₂ is 20 liter / min, NH ₃ is 10 liter / min, and TMG is used.
Was supplied at a rate of 1.7 × 10 ⁻⁴ mol / min and CP ₂ Mg at a rate of 3 × 10 ⁻⁶ mol / min for 3 minutes to form a 0.2 μm thick GaN high carrier concentration p ⁺ layer 52. In this state, the high carrier concentration p ⁺ layer 52 is still an insulator having a resistivity of 10 ⁸ Ωcm or more.

Next, a high carrier concentration p ⁺ layer 52 and a low carrier concentration p layer 5 are used by using a backscattered electron diffraction apparatus.
1 was uniformly irradiated with an electron beam. The electron beam irradiation conditions were: acceleration voltage 10 KV, sample current 1 μA, beam moving speed 0.2 mm /
sec, the beam diameter is 60 μmφ, and the degree of vacuum is 2.1 × 10 ⁻⁵ Torr. By the irradiation of the electron beam, the low carrier concentration p layer 51 is formed.
Is a p-conduction type semiconductor having a hole concentration of 1 × 10 ¹⁶ / cm ³ and a resistivity of 40 Ωcm, and the high carrier concentration p ⁺ layer 52 has a hole concentration of 2
It became a p-type semiconductor having × 10 ¹⁷ / cm ³ and resistivity of 2Ωcm.
Thus, a wafer having a multilayer structure as shown in FIG. 2 was obtained.

FIGS. 3 to 7 described below are cross-sectional views showing only one element on the wafer. Actually, for a wafer in which elements having the same structure are continuously formed,
Processing is performed, and then the wafer is cut for each device.

As shown in FIG. 3, a SiO ₂ layer 11 of 2000 Å is sputtered on the high carrier concentration p ⁺ layer 52.
It was formed in thickness. Next, a photoresist 12 was applied on the SiO ₂ layer 11. Then, by photolithography, on the high carrier concentration p ⁺ layer 52, the electrode formation site A corresponding to the hole 15 formed so as to reach the high carrier concentration n ⁺ layer 3 and the electrode formation portion are formed with the high carrier concentration p ⁺
The photoresist in the portion B where the groove 9 for insulating and separating from the electrode of the layer 52 was formed was removed.

Next, as shown in FIG. 4, the SiO ₂ layer 11 not covered with the photoresist 12 was removed with a hydrofluoric acid-based etching solution. Next, as shown in FIG.
The upper surface of the high carrier concentration p ⁺ layer 52 at a portion not covered by the photoresist 12 and the SiO ₂ layer 11 and the lower carrier concentration p layer 51, the low carrier concentration n layer 4, and the high carrier concentration n ⁺ layer 3 The part was dry-etched by supplying a degree of vacuum of 0.04 Torr, high-frequency power of 0.44 W / cm ² , and BCl ₃ gas at a rate of 10 milliliter / min, and then dry-etching with Ar. In this step, a hole 15 for extracting an electrode from the high carrier concentration n ⁺ layer 3 and a groove 9 for insulating and separating were formed.

Next, as shown in FIG. 6, the SiO ₂ layer 11 remaining on the high carrier concentration p ⁺ layer 52 was removed with hydrofluoric acid. Next, as shown in FIG.
The nickel layer 13 was formed by vapor deposition. As a result, the nickel layer 13 electrically connected to the high carrier concentration n ⁺ layer 3 is formed in the hole 15. Then, a photoresist 14 is applied on the nickel layer 13, and a predetermined photolithography is performed so that the photoresist 14 has an electrode portion for the high carrier concentration n ⁺ layer 3 and the high carrier concentration p ⁺ layer 52. A pattern was formed into a shape.

Next, as shown in FIG. 7, the exposed portion of the lower nickel layer 13 was etched with a nitric acid-based etching solution using the photoresist 14 as a mask. At this time, the nickel layer 13 deposited on the trench 9 for insulation isolation is completely removed. Next, the photoresist 14 was removed with acetone, and the electrode 8 of the high carrier concentration n ⁺ layer 3 and the electrode 7 of the high carrier concentration p ⁺ layer 52 were left. Thereafter, the wafer processed as described above was cut into individual devices to obtain a gallium nitride-based light emitting device having a pn structure shown in FIG.

The relationship between the voltage V applied to the light emitting diode 10 and the flowing current I was measured. FIG. 8 shows the result. For comparison, FIG. 9 shows the measurement results of the VI characteristics when the electrode was formed of aluminum. The driving threshold voltage dropped from 7V to 3V.

The light emission intensity of the light emitting diode 10 manufactured as described above at a drive current of 20 mA was measured.
The emission luminance is 10 mcd, which is equivalent to that of the conventional pn junction GaN.
The luminance was twice as high as that of the light emitting diode. or,
Device lifetime was 10 ⁴ hours, was 1.5 times that of the device life of the GaN light emitting diodes of a conventional pn junction.

The magnesium (Mg) used in the above examples
As the doping gas, methyl cyclopentadienyl magnesium Mg (C ₆ H ₇ ) ₂ may be used in addition to the above-mentioned gases.
Further, the above-mentioned p layer may be formed as a single layer as shown in FIG. In this case, the hole concentration of the p layer 5 is 1 × 10 ¹⁶ to 1
× 10 ¹⁹ / cm ³ . Alternatively, only the electrode 7 for the p layer 52 may be nickel, and the electrode 8 for the high carrier concentration n ⁺ layer 3 may be aluminum.

The low carrier concentration p-layer 51 has a hole concentration of 1 × 10 ¹⁴ / cm ³ to 1 × 10 ¹⁶ / cm ³ and a film thickness of 0.2 to 1
μm is desirable. When the hole concentration is 1 × 10 ¹⁴ / cm ³ or less, the series resistance becomes too high, which is not desirable, and when the hole concentration is 1 × 10 ¹⁶ / cm ³ or more, the low carrier concentration n
This is not desirable because the matching with the layer 4 is poor and the luminous efficiency is reduced. Further, if the film thickness is 1 μm or more, the series resistance becomes high, which is not desirable, and if it is 0.2 μm or less, the emission brightness is lowered, which is not desirable.

Further, it is desirable that the high carrier concentration p ⁺ layer 52 has a hole concentration of 1 × 10 ¹⁶ / cm ³ or more and a film thickness of 0.1 to 0.5 μm. If the hole concentration is less than 1 × 10 ¹⁶ / cm ³ , the series resistance increases, which is not desirable. The film thickness is 0.5 μ
When the thickness is more than m, the series resistance increases, which is not desirable. When the thickness is less than 0.1 μm, the hole injection efficiency decreases, which is not desirable.

Second Embodiment In FIG. 11, a light emitting diode 10 has a sapphire substrate 1, and the sapphire substrate 1 has 500 Å Al.
An N 2 buffer layer 2 is formed. The buffer layer 2
On the top, in order, the film thickness is about 2.2 μm, and the electron concentration is 2 × 10 ¹⁸ / c
High carrier concentration n ⁺ layer 3 composed of m ³ silicon-doped GaN, film thickness of about 1.5 μm, electron concentration of 1 × 10 ¹⁶ / cm ³ non-doped Ga
A low carrier concentration n layer 4 made of N 2 is formed. Further, on the low carrier concentration n-layer 4, a film thickness of about 0.2
μm, low impurity concentration i-layer 61 composed of Mg-doped GaN having a Mg concentration of 1 × 10 ¹⁹ / cm ³ , a film thickness of about 0.5 μm, and a Mg concentration of 2 × 10 ²⁰ / cm ³
High impurity concentration i ⁺ layer 62 is formed.

Then, in the predetermined regions of the low impurity concentration i layer 61 and the high impurity concentration i ⁺ layer 62, low carriers having a hole concentration of 1 × 10 ¹⁶ / cm ³ which have been made p-conductive by electron beam irradiation are respectively provided. A high carrier concentration p ⁺ layer 502 having a concentration p layer 501 and a hole concentration 4 × 10 ¹⁷ / cm ³ is formed.

[0029] Further, from the upper surface of the high impurity concentration i ⁺ layer 62, the high impurity concentration i ⁺ layer 62, low impurity concentration i layer 61,
A hole 15 penetrating through the low carrier concentration n layer 4 and reaching the high carrier concentration n ⁺ layer 3 is formed. An electrode 81 made of nickel joined to the high carrier concentration n ⁺ layer 3 through the hole 15 is formed on the high impurity concentration i ⁺ layer 62. Further, on the upper surface of the high carrier concentration p ⁺ layer 502, the electrode 71 formed of nickel for high carrier concentration p ⁺ layer 502 is formed. High carrier concentration n ⁺ layer 3
Is separated from the high carrier concentration p ⁺ layer 502 and the low carrier concentration p layer 501 by the high impurity concentration i ⁺ layer 62 and the low impurity concentration i layer 61.

Next, a method of manufacturing the light emitting diode 10 having this structure will be described. FIGS. 12 to 17 showing the manufacturing process are cross-sectional views of only one element on the wafer, and the following manufacturing process is actually performed on the wafer on which the elements shown in the drawing are repeatedly formed. Then, finally, the wafer is cut to form each light emitting element.

The wafer shown in FIG. 12 is manufactured in the same manner as in the first embodiment. Next, as shown in FIG. 13, the SiO ₂ layer 1 is formed on the high impurity concentration i ⁺ layer 62 by sputtering.
1 was formed to a thickness of 2000 mm. Next, a photoresist 12 was applied on the SiO ₂ layer 11. Then, the photoresist at the electrode formation site A corresponding to the hole 15 formed to reach the low carrier concentration n layer 4 in the high impurity concentration i ⁺ layer 62 was removed by photolithography.

Next, as shown in FIG. 14, the SiO ₂ layer 11 not covered with the photoresist 12 was removed with a hydrofluoric acid-based etching solution. Next, as shown in FIG. 15, the photoresist 12 and the SiO ₂ layer 11 a high impurity concentration of a portion not covered by the i ⁺ layer 62 and the low carrier concentration n layer 4 and the low impurity concentration i layer 61 thereunder A part of the upper surface of the high carrier concentration n ⁺ layer 3 was dry-etched by supplying a degree of vacuum of 0.04 Torr, high-frequency power of 0.44 W / cm ² , and BCl ₃ gas at a rate of 10 milliliter / minute, and then dry-etching with Ar. In this step, a hole 15 for extracting an electrode from the high carrier concentration n ⁺ layer 3 was formed. Next, as shown in FIG. 16, the SiO ₂ remaining on the high impurity concentration i ⁺ layer 62
Layer 11 was removed with hydrofluoric acid.

Next, as shown in FIG. 17, electron beams are irradiated to only predetermined regions of the high impurity concentration i ⁺ layer 62 and the low impurity concentration i layer 61 by using a reflection electron beam diffractometer, respectively. A high carrier concentration p ⁺ layer 502 having a hole concentration of 4 × 10 ¹⁷ / cm ³ and a low carrier concentration p layer 501 having a hole concentration of 1 × 10 ¹⁶ / cm ³ having a p-conduction type were formed.

The irradiation conditions of the electron beam were as follows: acceleration voltage 10 KV, sample current 1 μA, beam moving speed 0.2 mm / sec, beam diameter 60
μmφ, vacuum degree 2.1 × 10 ⁻⁵ Torr. At this time, portions other than the high carrier concentration p ⁺ layer 502 and the low carrier concentration p layer 501, that is, the portions not irradiated with the electron beam, are the high impurity concentration i ⁺ layer 62 and the low impurity concentration i layer 6 of the insulator.
It remains at 1. Therefore, the high carrier concentration p ⁺ layer 502
And the low carrier concentration p-layer 501 is:
Conduction is made to the low carrier concentration n layer 4, but in the lateral direction, the high impurity concentration i ⁺ layer 62 and the low impurity concentration i
It is electrically insulated and separated by the layer 61.

Next, as shown in FIG. 18, a high carrier concentration p ⁺ layer 502, a high impurity concentration i ⁺ layer 62, a high carrier concentration n ⁺ through the upper surface of the high impurity concentration i ⁺ layer 62 and the hole 15. ^A nickel layer 20 was formed on the ⁺ layer 3 by vapor deposition. Then, a photoresist 21 is applied on the nickel layer 20, and a predetermined photolithography is performed so that the photoresist 21 has an electrode portion for the high carrier concentration n ⁺ layer 3 and the high carrier concentration p ⁺ layer 502. A pattern was formed into a shape. Next, the photoresist 21
The exposed portion of the lower nickel layer 20 was etched with a nitric acid-based etchant using the mask as a mask, and the photoresist 21 was removed with acetone. Thus, as shown in FIG. 11, the electrode 81 of the high carrier concentration n ⁺ layer 3 and the electrode 71 of the high carrier concentration p ⁺ layer 502 were formed. Thereafter, the wafer formed as described above was cut for each element.

When the VI characteristics of the light emitting diode 10 manufactured in this way were measured, the characteristics similar to those of FIG. 8 were obtained. The driving voltage was 3V. When the luminescence intensity was measured, it was 10 mcd, as in the first embodiment.
Element lifetime was 10 ⁴ hours.

Third Embodiment In the light emitting diode of the first embodiment having the structure shown in FIG. 1, a high carrier concentration n ⁺ layer 3, a low carrier concentration n layer 4,
Low carrier concentration p layer 51, high carrier concentration p ⁺ layer 52
Was set to Al _0.2 Ga _0.5 In _0.3 N, respectively. The high carrier concentration n ⁺ layer 3 has an electron concentration of 2 × 10 ¹⁸ / c
m ³ , and the low carrier concentration n-layer 4 was formed at an electron concentration of 1 × 10 ¹⁶ / cm ³ without adding impurities. Low carrier concentration p layer 5
No. 1 is formed by adding magnesium (Mg) and irradiating an electron beam to form a hole concentration of 1 × 10 ¹⁶ / cm ³ , and a high carrier concentration p ⁺ layer 52.
Was added to magnesium (Mg) and irradiated with an electron beam to form a hole concentration of 2 × 10 ¹⁷ / cm ³ . The electrode 7 made of nickel connected to the high carrier concentration p ⁺ layer 52
And an electrode 8 made of nickel and connected to the high carrier concentration n ⁺ layer 3.

Next, the light emitting diode 10 having this structure can be manufactured similarly to the light emitting diode of the first embodiment. Trimethylindium (In (CH ₃ ) ₃ ) was used in addition to TMG, TMA, silane, and CP ₂ Mg gas. The generation temperature and gas flow rate are the same as in the first embodiment. The flow rates of the other gases are the same as in the first embodiment, except that trimethylindium is supplied at 1.7 × 10 ⁻⁴ mol / min.

Then, as in the first embodiment, the high carrier concentration p ⁺ layer 52 and the low carrier concentration p layer 51 are uniformly irradiated with an electron beam by using a reflection electron beam diffraction apparatus. A p-conduction type semiconductor could be obtained.

Next, similarly to the first embodiment, electrodes 7 and 8 made of nickel for the high carrier concentration n ⁺ layer 3 and the high carrier concentration p ⁺ layer 52 were formed.

The relationship between the voltage V applied to the light emitting diode 10 and the flowing current I was measured. As compared with the case where the electrodes were formed of aluminum, the drive threshold voltage was reduced from 7 V to 3 V, as in the first embodiment.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a manufacturing process of the light-emitting diode of the embodiment.

FIG. 3 is a sectional view showing a manufacturing step of the light-emitting diode of the embodiment.

FIG. 4 is a sectional view showing a manufacturing step of the light-emitting diode of the same embodiment.

FIG. 5 is a sectional view showing the manufacturing process of the light emitting diode of the same embodiment.

FIG. 6 is a sectional view showing the manufacturing process of the light-emitting diode of the example.

FIG. 7 is a sectional view showing the manufacturing process of the light emitting diode of the same embodiment.

FIG. 8 is a measurement diagram of a voltage-current characteristic of the light emitting diode of the same example.

FIG. 9 is a measurement diagram of voltage-current characteristics of a light-emitting diode using a conventional aluminum electrode.

FIG. 10 is a configuration diagram showing a configuration of a light emitting diode according to a modification of the first embodiment.

FIG. 11 is a configuration diagram showing a configuration of a light emitting diode according to a second specific example of the present invention.

FIG. 12 is a sectional view showing the manufacturing process of the light-emitting diode of the example.

FIG. 13 is a sectional view showing the manufacturing process of the light-emitting diode of the example.

FIG. 14 is a sectional view showing a manufacturing step of the light-emitting diode of the example.

FIG. 15 is a sectional view showing the manufacturing process of the light-emitting diode of the example.

FIG. 16 is a sectional view showing a manufacturing step of the light-emitting diode of the example.

FIG. 17 is a cross-sectional view showing the manufacturing process of the light-emitting diode of the example.

FIG. 18 is a cross-sectional view showing the manufacturing process of the light-emitting diode of the same example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Light-emitting diode 1 ... Sapphire substrate 2 ... Buffer layer 3 ... High carrier concentration n ⁺ layer 4 ... Low carrier concentration n layer 51,501 ... Low carrier concentration p layer 52,502 ... High carrier concentration p ⁺ layer 61 ... Low impurity Concentration i layer 62: High impurity concentration i ⁺ layer 7, 8, 71, 81 ... Electrode 9: Groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhide Masabe 1 Ochiai, Nagachi, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture, Toyoda Gosei Co., Ltd. (72) Inventor Masahiro Kotaki Ochiai, Nagachi, Kasuga-cho, Aichi-ken 1 Address: Toyoda Gosei Co., Ltd. (72) Inventor, Kuki Kato, Nishiokasugai-gun, Aichi Prefecture Ochiai, Nagahata 1 No. 1 Toyoda Gosei Co., Ltd. Synthetic Co., Ltd. (72) Inventor Yu Akasaki 1-3-1, Joshi, Nishi-ku, Nagoya-shi Aichi Prefecture 38-805 (72) Inventor Hiroshi Amano 2-21, Kamioka-cho, Meito-ku, Nagoya-shi, Aichi Room 103, Bldg. 19, Nijigaoka Higashi housing complex ( 56) References JP-A-3-252177 (JP, A) JP-A-4-242985 (JP, A) JP-A-4-68579 (JP, A) ) Patent flat 4-163972 (JP, A) JP Akira 59-228776 (JP, A)

Claims (7)

(57) [Claims] 1. An n-type nitrogen-group III element compound semiconductor (Al _x
Ga _Y In _1-XY N; X = 0, Y = 0, and X = Y = 0).
p-type nitrogen-group III element compound semiconductor (Al _x Ga _Y In _1-XY N; X =
0, Y = 0, X = Y = 0).
In the group element compound semiconductor light emitting device, the p layer has a high carrier concentration of 1 × 10 ¹⁶ / cm ³ or more.
(A) holes with higher concentration p ⁺ layer and higher carrier concentration p ⁺ layer
An electrode composed of a double layer of a low carrier concentration p layer having a low concentration, and an electrode bonded to the high carrier concentration p ⁺ layer is made of nickel.
(Ni) and nitrogen-group 3 element compound
Semiconductor light emitting device. 2. The magnesium (Mg) is added to the p-layer.
The nitrogen-3 group element according to claim 1, wherein
Element compound semiconductor light emitting device. 3. The low carrier concentration p-layer has a hole concentration of
A contract characterized by being 1 × 10 ¹⁴ to 1 × 10 ¹⁶ / cm ^3.
The nitrogen-3 group element compound semiconductor according to claim 1 or claim 2.
Body light emitting device. 4. The high carrier concentration p ⁺ layer is 0.1 to
Claim 1及, characterized in that it has a thickness of 0.5μm
The nitrogen-group 3 element compound semiconductor light emitting device according to claim 3 . 5. The low carrier concentration p-layer is 0.2-1.
The thickness of 0 μm, the claim 1 and the contract.
Nitrogen -3 group element compound semiconductor light-emitting device according to Motomeko 4. 6. The nitrogen, according to claim 1 及至claim 5 electrode joined to the n layer and the electrode to be joined to the high carrier concentration p ⁺ layer, characterized in that formed on the same side
Group-3 element compound semiconductor light emitting device. 7. The low carrier concentration p-layer and the high carrier concentration p-layer
Rear concentration p ⁺ layer is semi-insulating nitrogen -3-group element compound nitrogen -3 group of claim 1 to claim 6 a part of the semiconductor layer, characterized in that formed by p-type element compound semiconductor onset <br/> Optical device.