JPH06151966A - Nitrogen-iii compound semiconductor luminous element and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the luminance and life of an AlGaInN light emitting diode. CONSTITUTION:A 500Angstrom AlN buffer layer 2, high carrier concentration n<+>-layer 3, approx. 2.2mum in film thickness and 2X10<18>/cm<3> in electron density, made of silicon-doped GaN, low carrier concentration n-layer 4, approx. 1.5mum and 1X10<16>/cm<3>, made of non-doped GaN, and p-layer 5, are formed on a sapphire substrate 1 in this order. The p-layer is of multilayer structure and consists of five sets of two layers; each set comprises a low carrier concentration p-layer L1, approx. 500Angstrom in film thickness and 1X10<16>/cm<3> in hole density, made of Mg-doped GaN and a high carrier concentration p<+>-layer H1, approx. 500Angstrom and 2X10<17>/cm<3>. As a result, the luminance and life are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blue light-emitting nitrogen-group III compound semiconductor light-emitting device.

[0002]

2. Description of the Related Art Conventionally, as a blue light emitting diode, one using a GaN compound semiconductor has been known. Its GaN
Since the compound semiconductors of the type are direct transition type, they have high luminous efficiency, and blue, which is one of the three primary colors of light, is used as the emission color, and so on.

Recently, it has become clear that p-type GaN can be obtained by doping Mg and irradiating it with an electron beam. As a result, the conventional n layer and semi-insulating layer (i
A GaN light emitting diode having a pn junction instead of a junction with a layer) has been proposed.

[0004]

However, even the light emitting diode having the above-mentioned pn junction has not yet obtained sufficient light emission brightness, and has not obtained a sufficient lifetime. Therefore, an object of the present invention is to provide a nitrogen-3 group compound semiconductor (including Al _x Ga _Y In _1-XY N; X = 0, Y = 0, X = Y = 0).
It is to improve the light emission brightness of the light emitting diode and to prolong the life of the device.

[0005]

The present invention is directed to n-type nitrogen-
Group 3 element compound semiconductor (Al _x Ga _Y In _1-XY N; X = 0, Y = 0, X = Y = 0
Layer) and a p-layer composed of a p-type nitrogen-group-3 element compound semiconductor (including Al _x Ga _Y In _1-XY N; X = 0, Y = 0, X = Y = 0) In a nitrogen-3 group compound semiconductor light emitting device having: a p layer, a low carrier concentration p layer having a relatively low hole concentration and a high carrier concentration having a relatively high hole concentration from a side where the p layer is joined to the n layer. One cycle with the concentration p ⁺ layer,
It is characterized in that it is formed by repeating a plurality of cycles.

The hole concentration of the above low carrier concentration p-layer is
1 × 10 ¹⁴ / cm ³ to 1 × 10 ¹⁶ / cm ³ is desirable, and the hole concentration of the high carrier concentration p ⁺ layer is preferably 1 × 10 ¹⁶ / cm ³ to 2 × 10 ¹⁷ / cm ³ . The film thickness is preferably 100Å to 1000Å.

[0007]

According to the present invention, the p layer has a low carrier concentration p layer having a relatively low hole concentration and a high carrier concentration p having a relatively high hole concentration from the side where it is joined to the n layer.
As a result of repeatedly forming a plurality of cycles with the ⁺ layer as one cycle, the emission luminance was improved. The emission brightness is 10 mcd, which is twice as high as that of the conventional pn junction GaN light emitting diode. Further, the light emission lifetime is 10 ⁴ hours, which is 1.5 times the light emission lifetime of the conventional pn junction GaN light emitting diode.

[0008]

First Embodiment Referring to FIG. 1, a light emitting diode 10 has a sapphire substrate 1, and the sapphire substrate 1 has 500 Å AlN.
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 are sequentially formed.
The high carrier concentration n ⁺ layer 3 made of silicon-doped GaN and the low carrier concentration n layer 4 made of non-doped GaN having an electron concentration of 1 × 10 ¹⁶ / cm ³ are formed. Further, on the low carrier concentration n-layer 4, a p-layer 5 having a thin film multilayer structure is formed. The p layer 5 has a film thickness of about 500Å, a low carrier concentration p layer L ₁ made of Mg-doped GaN with a hole concentration of 1 × 10 ¹⁶ / cm ³ , a film thickness of about 500Å, and a hole concentration of 2 × 10 ¹⁷ / cm ³ . It has a multi-layered structure in which a high carrier concentration p-layer H ₁ made of Mg-doped GaN is repeatedly formed for 5 cycles. Then, an electrode 7 formed of nickel and connected to the highest carrier concentration p ⁺ layer H ₅ and an electrode 8 formed of nickel and connected to the high carrier concentration n ⁺ layer 3 are 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 is
It was manufactured by vapor phase epitaxy by an organometallic compound vapor phase epitaxy method (hereinafter referred to as "M0VPE"). The gas used is NH
₃ and carrier gas H ₂ and trimethylgallium (Ga (CH ₃ ) ₃ ).
(Hereinafter referred to as "TMG") and trimethyl aluminum (Al
(CH _{3) 3)} is referred to (hereinafter referred to as "TMA") and silane (SiH ₄₎ and bis-cyclopentadienyl magnesium _{(Mg (C 5 H 5)} 2) ( hereinafter "CP ₂ Mg").

First, the single-crystal sapphire substrate 1 whose main surface is the A-plane cleaned by organic cleaning and heat treatment is mounted on a susceptor placed in the reaction chamber of the M0VPE apparatus. Then, at a pressure of 1100 while flowing H ₂ into the reaction chamber at a flow rate of 2 liter / min under normal pressure.
The sapphire substrate 1 was vapor-phase etched at 0 ° C.

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
The buffer layer 2 of AlN was formed at a thickness of about 500Å by supplying at a mol / min. Next, the temperature of the sapphire substrate 1 is set to 1150.
Hold at ₂ ℃, H ₂ 20 liter / min, NH ₃ 10 liter / min,
Silane (SiH ₄ ) diluted with TMG at 1.7 × 10 ^-4 mol / min and 0.86 ppm with H ₂ was supplied at a rate of 200 ml / min for 30 minutes to obtain a film thickness of about 2.2 μm and electron concentration of 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 20 liter / min, NH ₃ 10 liter / min, TMG
For 20 minutes at a rate of 1.7 × 10 ^-4 mol / min,
A low carrier concentration n layer 4 made of GaN having an electron concentration of 1 × 10 ¹⁶ / cm ^{3 and having} a thickness of 1.5 μm was formed.

Next, the sapphire substrate 1 is heated to 1150 ° C.,
H ₂ 20 liter / min, NH ₃ 10 liter / min, TMG 1.7
× 10 ^-4 mol / min, CP ₂ Mg at a rate of 8 × 10 ^-8 mol / min.
It is supplied for 7 minutes to obtain Ga with a Mg concentration of 5 × 10 ¹⁹ / cm ³ and a film thickness of 500 Å.
A low carrier concentration p-layer L ₁ made of N ₂ was formed. In this state, the low carrier concentration p layer L ₁ still has a resistivity of 10 ⁸
It is an insulator of Ωcm or more.

Next, the sapphire substrate 1 is heated to 1150 ° C.,
H ₂ 20 liter / min, NH ₃ 10 liter / min, TMG 1.7
× 10 ⁻⁴ mol / min, CP ₂ Mg at a rate of 3 × 10 ⁻⁷ mol / min.
It is supplied for 7 minutes to obtain Ga with a Mg concentration of 2 × 10 ²⁰ / cm ³ and a film thickness of 500 Å.
A high carrier concentration p ⁺ layer H ₁ made of N ₂ was formed. In this state, the high carrier concentration p ⁺ layer H ₁ still has a resistivity of 10
It is an insulator of ⁸ Ωcm or more.

Subsequently, the steps of forming the low carrier concentration p layer and the high carrier concentration p ⁺ layer are further repeated for 4 cycles, and as shown in FIG. 2, the p layer having a multilayer structure of 5 cycles as a whole. Got 5.

Next, using a backscattered electron beam diffractometer, the p-layer 5 having the above-mentioned multilayer structure was uniformly irradiated with an electron beam. The electron beam irradiation conditions are: acceleration voltage 10 KV, sample current 1 μA, beam moving speed 0.2 mm / sec, beam diameter 60 μmφ, vacuum degree 2.
It is 1 × 10 ^-5 Torr. By this electron beam irradiation, the low carrier concentration p layers L _{1 to} L ₅ have a hole concentration of 1 × 10 ¹⁶ / cm ³ ,
It becomes a p-conductivity type semiconductor with a resistivity of 40 Ωcm, and the high carrier concentration p ⁺ layers H _{1 to} H ₅ have a hole concentration of 2 × 10 ¹⁷ / cm ³ and a resistivity of
It became a p-type semiconductor of 2 Ωcm. In this way, 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. In fact, a wafer in which this element is continuously repeated is processed, and then each of the elements is processed. It is cut for each element.

As shown in FIG. 3, a SiO ₂ layer 11 of 2000 Å is formed on the high carrier concentration p ⁺ layer H ₅ by sputtering.
Formed to a thickness of. Next, a photoresist 12 was applied on the SiO ₂ layer 11. Then, by photolithography, on the high carrier concentration p ⁺ layer H ₅ , the electrode forming portion A corresponding to the hole 15 formed so as to reach the high carrier concentration n ⁺ layer 3 and the electrode forming 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 H ₅ is formed is 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.
A part of the upper surface of the p-layer 5 having a multi-layer structure which is not covered with the photoresist 12 and the SiO ₂ layer 11 and the low carrier concentration n layer 4 and the high carrier concentration n ⁺ layer 3 under the p-layer 5 has a vacuum degree of 0.04. Torr, high frequency power 0.44 W / cm ² , BCl ₃ gas 10 ml
It was supplied at a rate of / min and dry-etched, and then Ar was dry-etched. In this step, a hole 15 for taking out an electrode and a groove 9 for insulation separation were formed for the high carrier concentration n ⁺ layer 3.

Next, as shown in FIG. 6, the SiO ₂ layer 11 remaining on the high carrier concentration p ⁺ layer H ₅ was removed with hydrofluoric acid. Next, as shown in FIG.
The Ni layer 13 was formed by vapor deposition. As a result, the Ni 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 Ni layer 13, and the photoresist 14 is subjected to photolithography so that the electrode portion for the high carrier concentration n ⁺ layer 3 and the high carrier concentration p ⁺ layer H ₅ remains.
A pattern was formed into a predetermined shape.

Next, as shown in FIG. 7, the exposed portion of the lower Ni layer 13 was etched with a nitric acid-based etching solution using the photoresist 14 as a mask. At this time, the Ni layer 13 deposited in the groove 9 for insulation separation is completely removed.
Next, the photoresist 14 is removed with acetone, the electrode 8 of the high carrier concentration n ⁺ layer 3 and the high carrier concentration p ⁺ layer H ₅ are removed.
Of the electrode 7 was left. Then, the wafer treated as described above was cut into each element to obtain a pn structure gallium nitride-based light emitting element shown in FIG.

The light emission intensity of the light emitting diode 10 manufactured in this manner was measured and found to be 10 mcd, which was twice as high as that of the conventional pn junction GaN light emitting diode. The light emission life was 10 ⁴ hours, which was 1.5 times that of the conventional pn junction GaN light emitting diode. Since the p layer 5 has a thin film multilayer structure, the low carrier concentration n layer 4 of holes is formed.
It was possible to increase the injection amount of holes into the.

The magnesium Mg doping gas used in the above embodiment may be methylbiscyclopentadienyl magnesium Mg (C ₆ H ₇ ) ₂ in addition to the above gases.

The electron concentration of the low carrier concentration n layer 4 is 1
It is desirable that the film thickness is x10 ¹⁴ to 1x10 ¹⁶ / cm ³ and the film thickness is 0.5 to 2 µm. When the electron concentration is 1 × 10 ¹⁶ / cm ³ or more, the emission intensity decreases, which is not desirable. When the electron concentration is 1 × 10 ¹⁴ / cm ³ or less, the series resistance of the light emitting element becomes too high and heat is generated when an electric current is applied. . Further, if the film thickness is 2 μm or more, the series resistance of the light emitting element becomes too high and heat is generated when an electric current is applied, which is not desirable, and if the film thickness is 0.5 μm or less, the emission intensity decreases, which is not desirable.

Further, it is desirable that the high carrier concentration n ⁺ layer 3 has an electron concentration of 1 × 10 ¹⁶ to 1 × 10 ¹⁹ / cm ³ and a film thickness of 2 to 10 μm. When the electron concentration is 1 × 10 ¹⁹ / cm ³ or more, the crystallinity is deteriorated, which is not desirable. When the electron concentration is 1 × 10 ¹⁶ / cm ³ or less, the series resistance of the light emitting element becomes too high and heat is generated when a current is applied, which is not desirable. . Further, if the film thickness is 10 μm or more, the substrate is curved, which is not desirable.

The low carrier concentration p layers L _{1 to} L _{5 have} a hole concentration of 1 × 10 ¹⁴ to 1 × 10 ¹⁶ / cm ³ and a film thickness of 100 to 100 μm.
1000Å is desirable. If the hole concentration is 1 × 10 ¹⁶ / cm ³ or more, the matching with the low carrier concentration n-layer 4 is deteriorated and the luminous efficiency is lowered, which is not desirable.
If it is less than 1 × 10 ¹⁴ / cm ³ , the series resistance becomes too high, which is not desirable.

Further, the high carrier concentration p ⁺ layers H _{1 to} H _{5 have} a hole concentration of 1 × 10 ¹⁶ to 2 × 10 ¹⁷ / cm ³ and a film thickness of 100.
~ 1000Å is desirable. A p ⁺ layer having a hole concentration of 2 × 10 ¹⁷ / cm ³ or more cannot be formed. When it is 1 × 10 ¹⁶ / cm ³ or less, the series resistance becomes high, which is not desirable.

Second Embodiment A light emitting diode 10 may be constructed as shown in FIG. That is, on the buffer layer 2, a p-layer 5 having a thin film multi-layer structure, a film thickness of about 1.5 μm, and an electron concentration of 1 × 10 ¹⁶ / cm 2.
Low carrier concentration n-layer 4 composed of ³ undoped GaN, film thickness of about 2.2 μm, electron concentration of 2 × 10 ¹⁸ / cm ³ silicon doped
A high carrier concentration n ⁺ layer 3 made of GaN is formed. This p layer 5 is similar to that of the first embodiment, and the low carrier concentration p layer and the high carrier concentration p ⁺ layer are set as one cycle,
It is formed by repeating 5 cycles.

An electrode 8 made of nickel and connected to the high carrier concentration n ⁺ layer 3 and an electrode 7 made of nickel and connected to the high carrier concentration p ⁺ layer H ₅ are formed. The electrodes 8 and 7 have a groove 91 formed in the high carrier concentration n ⁺ layer 3, the low carrier concentration n layer 4, and the p layer 5.
Are electrically isolated from each other.

As described above, this embodiment is different from the first embodiment in that the deposition order of the p layer and the n layer on the substrate 1 is reversed. The manufacturing can be performed in the same manner as in the first embodiment.

As described above, since the two layers of the low carrier concentration p layer and the high carrier concentration p ⁺ layer from the side where the p layer is joined to the n layer are set as one period to have a multi-period structure, the hole concentration is the highest. By applying a voltage between the high p ⁺ layer and the n ⁺ layer with the highest electron concentration, electrons and holes are efficiently accelerated in each layer, and efficiently pass through the pn junction surface to the opposite conductivity type layer. Injected. As a result, the emission brightness was improved.

Third Embodiment In FIG. 9, a light emitting diode 10 has a sapphire substrate 1, and the sapphire substrate 1 has 500 Å AlN.
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 are sequentially formed.
High-concentration n ⁺ layer 3 made of silicon-doped GaN, film thickness of about 1.5 μm, low-carrier-concentration n-layer 4 made of non-doped GaN having an electron concentration of 1 × 10 ¹⁶ / cm ³ , i of the multilayer structure.
Layer 6 has been formed. The i-layer 6 has a film thickness of about 500Å, a low impurity concentration i-layer i _L1 with a Mg concentration of 5 × 10 ¹⁹ / cm ³ , and a film thickness of about 500.
Å, ₁ with high impurity concentration i-layer i _H1 with Mg concentration 2 × 10 ²⁰ / cm ³
It has a multi-layer structure in which five cycles are repeatedly formed.

Then, the low impurity concentration i layers i _{L1 to} i _L5
And the predetermined regions of high impurity concentrations i _{H1 to} i _H5 are each made to have a p-conductivity type by electron beam irradiation and have a film thickness of about 500 Å,
Low carrier concentration p layer L _{1 to} L with hole concentration 1 × 10 ¹⁶ / cm ³
₅ , high carrier concentration p layers H _{1 to} H ₅ having a film thickness of about 500 Å and a hole concentration of 2 × 10 ¹⁷ / cm ³ are formed. in this way,
A p-layer 50 having a multi-layer structure is formed at a part of the i-layer 6 having the multi-layer structure.

A hole 15 is formed from the upper surface of the high impurity concentration i ⁺ layer i _H5 to penetrate the i layer 6 and the low carrier concentration n layer 4 to reach the high carrier concentration n ⁺ layer 3. 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 i _H5 . Further, on the upper surface of the high carrier concentration p ⁺ layer H _5, electrodes 71 formed of nickel to high carrier concentration p ⁺ layer H ₅ is formed. The electrode 81 for the high carrier concentration n ⁺ layer 3 is the i layer 6 for the p layer 50.
It is insulated and separated by.

Next, a method of manufacturing the light emitting diode 10 having this structure will be described. 10 to 15 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. 10 is manufactured in the same manner as in the first embodiment. Next, as shown in FIG. 11, the SiO ₂ layer 1 is sputtered on the high impurity concentration i ⁺ layer i _H5.
1 was formed to a thickness of 2000Å. Next, a photoresist 12 was applied on the SiO ₂ layer 11. Then, by photolithography, the photoresist in the electrode formation site A corresponding to the hole 15 formed to reach the high carrier concentration n ⁺ layer 3 in the high impurity concentration i ⁺ layer i _H5 was removed.

Next, as shown in FIG. 12, 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. 13, the i layer 6 having a multilayer structure in a portion not covered with the photoresist 12 and the SiO ₂ layer 11, the low carrier concentration n layer 4 and the high carrier concentration n ⁺ layer 3 thereunder. Part of the upper surface of
Vacuum degree 0.04 Torr, high frequency power 0.44 W / cm ² , BCl ₃ gas 10
It was supplied at a rate of ml / min for dry etching, and then Ar was used for dry etching. In this process, high carrier concentration n ⁺
Holes 15 were formed in the layer 3 for electrode extraction.
Next, as shown in FIG. 14, the SiO ₂ layer 11 remaining on the high impurity concentration i ⁺ layer i _H5 was removed with hydrofluoric acid.

Next, as shown in FIG. 15, a backscattered electron beam diffractometer is used only in predetermined regions of the high impurity concentration i ⁺ layers i _{H1 to} i _H5 and the low impurity concentration i layers i _{L1 to} i _L5. High carrier concentration p layers H _{1 to} H ₅ having a film thickness of about 500 Å and a hole concentration of 2 × 10 ¹⁷ / cm ³ , each of which exhibits p-conductivity upon irradiation with an electron beam,
Low carrier concentration p layers L _{1 to} L ₅ having a film thickness of about 500 Å and a hole concentration of 1 × 10 ¹⁶ / cm ³ were formed.

The electron beam irradiation conditions are: 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, the high carrier concentration p ⁺ layers H _{1 to} H ₅ and the low carrier concentration p layer L ₁
Portions other than ~L _5, i.e., irradiated not part of the electron beam remains high impurity concentration i ⁺ layer i _H1 through i _H5 and low impurity concentration i layer i _L1 through i _L5 of the insulator. Therefore, the high carrier concentration p ⁺ layers H _{1 to} H ₅ and the low carrier concentration p layer L ₁
.About.L ₅ are electrically connected to the low carrier concentration n layer 4 in the vertical direction, but are high impurity concentration i ⁺ layers i _{H1 to} i _H5 and a low impurity concentration i layer in the horizontal direction with respect to the surroundings. It is electrically insulated and separated by i _{L1 to} i _L5 .

Next, as shown in FIG. 16, a high carrier concentration p ⁺ layer H ₅ , a high impurity concentration i ⁺ layer i _H5 , a high impurity concentration i ⁺ layer i _H5 , and an upper surface of the high impurity concentration i ⁺ layer i _H5 and a hole 15 are formed. A Ni layer 20 was formed on the carrier concentration n ⁺ layer 3 by vapor deposition. Then, a photoresist 21 is applied on the Ni layer 20, and the photoresist 21 is applied by photolithography.
Are high carrier concentration n ⁺ layer 3 and high carrier concentration p ⁺ layer H
_A pattern was formed in a predetermined shape so that the electrode portion for ₅ remained. Next, using the photoresist 21 as a mask, the exposed portion of the lower Ni layer 20 was etched with a nitric acid-based etching solution, and the photoresist 21 was removed with acetone. Thus, as shown in FIG. 9, the high carrier concentration n ⁺
Electrode 81 of layer 3 and electrode 71 of high carrier concentration p ⁺ layer H ₅
Was formed. After that, the wafer formed as described above was cut into each element.

The light emission intensity of the light emitting diode 10 manufactured in this manner was measured and found to be 10 mcd and the light emission life was 10 ⁴ hours, as in the first embodiment.

Fourth Embodiment In the light emitting diode of the first embodiment having the structure shown in FIG. 1, a high carrier concentration n ⁺ layer 3 and a p layer 5 having a multi-layer structure are provided.
Al _0.2 Ga _0.5 In _0.3 N was used for each. High carrier concentration n
^{The +} layer 3 was formed by adding silicon to an electron concentration of 2 × 10 ¹⁸ / cm ³ , and the low carrier concentration n layer 4 was formed without adding impurities to an electron concentration of 1 × 10 ¹⁶ / cm ³ . The low carrier concentration p layer L ₁ has a hole concentration by adding magnesium (Mg) and irradiating it with an electron beam.
Formed in 1 × 10 ¹⁶ / cm ^3, was formed on the high carrier concentration p layer H ₁ is irradiated with the electron beam also doped with magnesium (Mg) hole concentration 2 × 10 ¹⁷ / cm ^3. Then, an electrode 7 made of nickel and connected to the highest carrier concentration p ⁺ layer H ₅ and an electrode 8 made of nickel and connected to the high carrier concentration n ⁺ layer 3 were formed.

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, 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 those in the first embodiment except that trimethylindium is supplied at 1.7 × 10 ⁻⁴ mol / min.

Then, as in the first embodiment, a p-type semiconductor is obtained by uniformly irradiating the p-layer 5 having the above-mentioned multi-layer structure with an electron beam by using a reflection electron beam diffractometer. I was able to.

Next, similarly to the first embodiment, electrodes 7 and 8 made of nickel and connected to the high carrier concentration p ⁺ layer H ₅ and the high carrier concentration n ⁺ layer 3 were formed.

The light emission intensity of the light emitting diode 10 thus manufactured was measured and found to be 10 mcd, which was twice as high as that of the conventional pn junction GaN light emitting diode. The light emission life was 10 ⁴ hours, which was 1.5 times that of the conventional pn junction GaN light emitting diode. Since the p layer 5 has a thin film multilayer structure, the low carrier concentration n layer 4 of holes is formed.
It was possible to increase the injection amount of holes into the.

[Brief description of 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 cross-sectional view showing a manufacturing process of the light emitting diode of the same embodiment.

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

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

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

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

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

FIG. 8 is a configuration diagram showing a configuration of a light emitting diode according to a second specific example of the present invention.

FIG. 9 is a configuration diagram showing a configuration of a light emitting diode according to a third specific example of the present invention.

FIG. 10 is a sectional view showing a manufacturing process of the light emitting diode of the embodiment.

FIG. 11 is a cross-sectional view showing the manufacturing process of the light-emitting diode of the example.

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

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

FIG. 14 is a sectional view showing a manufacturing process of the light emitting diode of the embodiment.

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

FIG. 16 is a sectional view showing a manufacturing process of the light emitting diode of the embodiment.

[Explanation of symbols]

10 ... Light emitting diode 1 ... Sapphire substrate 2 ... Buffer layer 3 ... High carrier concentration n ⁺ layer 4 ... Low carrier concentration n layer 5, 50 ... p layer (p layer of multi-layer structure) 6 ... i layer (of multi-layer structure) i layer) i _{H1 to} i _H5 ... High impurity concentration i layer i _{L1 to} i _L5 ... Low impurity concentration i layer 7, 8 ... Electrode 9 ... Groove

Front Page Continuation (72) Inventor Junichi Umezaki, 1 Ochiai, Nagachi, Kasuga-cho, Nishikasugai-gun, Aichi Prefecture, Toyoda Gosei Co., Ltd. Within the corporation

Claims (1)

[Claims] 1. An n-type nitrogen-3 group element compound semiconductor (Al _x
Ga _Y In _1-XY N; including X = 0, Y = 0, X = Y = 0)),
p-type nitrogen-3 group compound semiconductor (Al _x Ga _Y In _1-XY N; X =
0, Y = 0, X = Y = 0 inclusive) and nitrogen-3 with
In the genus element compound semiconductor light emitting device, the p layer is a low carrier concentration p layer having a relatively low hole concentration and a high carrier concentration p ⁺ layer having a relatively high hole concentration from a side where the p layer is joined to the n layer. A light-emitting element characterized by being formed by repeating a plurality of cycles, each of which is defined as one cycle.