JP2001320089A - GaN-based light emitting device and method for producing the same - Google Patents

Abstract

(57) [Problem] To provide a high-quality GaN-based light-emitting device using GaNP or GNAs as an active layer, and a method for producing the same. SOLUTION: A p-type G laminated on an n-type GaN layer 13 is provided.
P ions are ion-implanted into the aN layer 14 and then heated to form a GaNP layer 15 serving as an active layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GaN-based light emitting device containing As or P and a method for producing the same, and more particularly, to forming an active layer of the GaN-based light emitting device, As or P is ion-implanted into a GaN layer. The present invention relates to a GaN-based light emitting device and a method for manufacturing the same.

[0002]

2. Description of the Related Art In order to realize full color by a light emitting diode (LED), it is necessary to emit light of three primary colors of red, green and blue.
Development of D has not progressed for many years. However, in recent years, a high-brightness blue LED using a GaN-based compound semiconductor has been realized, and a high-brightness green LED using a similar material has also been developed. With this, the existing red L
Along with the ED, research and development of full color light emitting devices and white light emitting devices using LEDs have been actively conducted.

GaN (gallium nitride) is a material belonging to a group III-V nitride semiconductor according to the classification of compound semiconductors based on the periodic table, and has a hexagonal wurtzite structure. is there. Other materials belonging to this group III-V nitride semiconductor include aluminum nitride (Al
N) and indium nitride (InN). Since all of these have direct transition energy band structures, Si
It is known as a material having essentially excellent characteristics in terms of luminous efficiency as compared with a material belonging to the indirect transition type such as C.

Further, these mixed crystals (Al, Ga,
In) N can change the band gap energy Eg in a wide range from 1.95 to 6.28 eV depending on the mixed crystal ratio. Therefore, there is a possibility that not only blue light but also all colors in the visible region from ultraviolet to red can be realized as colored light. Furthermore, features such as high melting point, high hardness, and high thermal conductivity common to these materials can be a highly reliable device having excellent environmental resistance, and thus are particularly promising as a material for a light emitting device.

In general, a thin film is formed by epitaxial growth when producing an LED or LD (laser diode), and a substrate to be used is required to have a lattice constant that is high enough to match the luminescent material.
If this requirement is not satisfied, the crystal structure of the thin film is different from the crystal structure of the substrate, and a mismatch occurs in the lattice constant. Will be invited.

However, in the production of GaN-based LEDs, there are no commercially available substrates for epitaxial growth with matching lattice constants, and even in a sapphire substrate actually used for growth, the lattice constant is shifted by almost 15%. ing. For this reason, it is very difficult to grow a high-quality crystal, and it has been long in the past that no technological progress has been made as a light-emitting element.

In order to grow GaN, the substrate needs to be
2,000 ° C., but at this temperature the vapor pressure of GaN increases,
It is extremely difficult to improve the crystallinity of the film,
GaN also had a problem that a p-type crystal could not be formed, which made it more difficult to realize a GaN-based light emitting device.

Under such a background, first, Al
GaN after forming a thin buffer layer with N or GaN
It has been found that growing the film dramatically improves the crystallinity, thereby solving the problem of crystallinity due to lattice mismatch. In addition, it has been found that a low-resistance p-type GaN film is formed by irradiating an electron beam or performing a thermal annealing process on the Mg-doped GaN film. As a result, at present, GaN
A pn junction of a system material can be realized, and a blue LED using a GaN compound semiconductor has been obtained. Furthermore, at present, InGaN with higher luminous efficiency
A blue LED is also realized by such a mixed crystal film.

In the following, GaN having an active layer of InGaN will be described.
A typical method for producing a system LED will be described. GaN
A system LED is provided as a multilayer structure of thin films, and here, MOCVD (Meta) is used as a method of forming the thin films.
l-Organic Chemical Vapor
The case where the (Deposition) method is adopted will be described.

First, when fabricating a GaN-based LED, a GaN buffer layer is grown on a semi-insulating sapphire substrate or a conductive SiC substrate using dimethylhydrazine (DMH) and trimethylgallium (TMG).

Furthermore, TMG, ammonia (NH ₃ ) and silane (SiH ₄ ) are further used as gas raw materials.
At a growth temperature of 1050 ° C., a Si-doped n-type GaN layer is grown. Further, trimethylaluminum (TMA) was added to the above raw material, and a growth temperature of 1050 ° C.
, An n-type AlGaN layer functioning as a cladding layer is grown. Then, a non-doped InGaN layer serving as an active layer is formed thereon at the same temperature using trimethylindium (TMI), TMG, and NH ₃ as gas raw materials.

Further, a p-type AlGaN layer serving as another clad layer is grown thereon at the same temperature using cyclopentadienyl magnesium (CpMg) as a dopant. Finally, a p-type GaN layer is grown at the same temperature using biscyclopentadienyl magnesium (bCpMg) as a dopant.

As described above, the laminated film constituting the LED is:
A buffer layer deposited at low temperature on a sapphire substrate, etc.
Generally, the order of the n-type low resistance layer, the n-type cladding layer, the active layer, the p-type cladding layer, and the p-type low resistance layer is as follows.

After laminating the above thin film, SiO ₂ or the like is deposited on the surface thereof using a plasma CVD apparatus, and patterning for forming an n-type electrode is performed using a photoresist and dry etching. In this case, the n-type GaN layer is partially etched, and a metal such as Ti / Al is vapor-deposited on the upper surface to form an n-type electrode. On the other hand, the p-type electrode is formed by depositing a metal such as Au / Ni on the upper surface of the p-type GaN layer.

As described above, the G layer having InGaN as the active layer
An aN-based LED has also been well-established in its production method, and furthermore, has high luminance emission obtained by forming a luminescence center by adding In. Therefore, the aN-based LED has been widely marketed as an actual product. However, in the LED using InGaN as an active layer, when trying to realize other colors by changing the doping amount of In, blue and green light emission satisfies sufficient practical use, but at most on the long wavelength side. At present, only light emission up to orange is confirmed, and at present, high-luminance light emission of red, which is one of the basic colors of RGB, has not been realized. That is, only the LED using InGaN as the active layer has not realized high-luminance light emission of all RGB basic colors by changing the doping ratio (composition ratio).

However, in recent years, phosphorus (P) or arsenic (A
It has been found that a GaN-based material added with s) is also promising as a material for a blue LED. Depending on the doping amount (composition ratio) of the additive, GaNP or GANAs doped with these additives can actually emit a wide range of high-brightness light from ultraviolet to red, thereby realizing a high-brightness full-color LED. It is expected. In particular, As and P added to GaN reduce lattice defects in GaN and act as an emission center, and are effective in increasing GaN band edge emission.

For example, GaNP has a composition formula of GaN _x P
_{In 1-x} , when the composition ratio x is a value near 0.95, blue light is emitted. When the composition ratio x is a value near 0.90, green light is emitted. It emits red light when the value is around .87. Thus, the GNP
Is from ultraviolet to infrared (3.34) depending on the amount of P added.
eV to -0.2 eV).

[0018]

However, GaP
And GaAs have a small energy gap with a substantially linear variation range with respect to the doping amount of P or As,
As described above, there is a problem that the energy gap of NAs and GANP changes greatly with respect to the doping amount of P and As, and the form of the change is non-linear, so that it is difficult to control the energy gap.

In the formation of a thin film, it is known that atoms and molecules that have collided with the surface of the substrate or the thin film are partially reflected, while others are left on the surface. The atoms and molecules remaining on the surface are surface-diffused (migrated) by their own energy and the energy of the temperature of the substrate, partly re-evaporated (desorbed), and others settled in a potential valley (adsorption). That is, in order to form a thin film, it is necessary to reduce desorption of material atoms and molecules and to sufficiently migrate and adsorb the entire substrate.

However, GNP and GNAs are converted to M
When a film is formed by the OCVD method or the like, when the substrate is at a high temperature of about 1000 ° C., P or As is easily desorbed, and there is a problem that it is difficult to obtain high-quality GNP or GNAs. Therefore, there has been a problem that a high quality active layer cannot be obtained and the luminous efficiency is low.

The occurrence of this desorption is caused by the occurrence of GNP or GNAs.
And the crystal structure of a sapphire substrate or the like are inconsistent. Therefore, even if a buffer layer is interposed, P and As remain on the substrate in a relatively high temperature state of about 1000 ° C. for a long time. This is due to the inability to stay in place. In the following, the term “migration” refers to a state of surface adsorption required to obtain a desired mixed crystal such as GANP or GANAs.

Therefore, it is difficult to dope a sufficient amount of P or As to GaNP or GNAs until the characteristics thereof become remarkable in a thin film forming method by a vapor phase growth method such as MOCVD. For this reason, for example, it is difficult to realize a full-color LED using one element by stacking GaNP double heterojunction layers having different composition ratios from each other.

The present invention has been made in view of the above, and uses an ion implantation method to obtain a group III-V nitride semiconductor such as GaNP or GaNAs as an active layer, thereby obtaining a light emission more than conventional InGaN. It is an object of the present invention to provide a high-quality GaN-based light emitting device having a wavelength range and a method for manufacturing the same.

[0024]

According to a first aspect of the present invention, there is provided a semiconductor device comprising: a p-type GaN-based compound semiconductor layer; and an n-type GaN-based compound semiconductor layer joined to the p-type GaN-based compound semiconductor layer. A compound semiconductor layer;
A GaN-based compound semiconductor layer or a n-type GaN-based compound semiconductor layer, which is formed by ion-implanting As (arsenic) or P (phosphorus) into the n-type GaN-based compound semiconductor layer and then performing a heat treatment. It is characterized by having.

According to the present invention, the GNAs layer or G
An aNP layer is formed by ion-implanting As or P into one of the pn-junction p-type GaN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer, and then heating the GaN-based compound semiconductor layer. Therefore, a GaNAs layer or a GaNP layer sufficiently mixed with As or P can be provided as an active layer of the LED.

Further, the invention according to claim 2 provides a p-type Ga
An N-based compound semiconductor layer, an n-type GaN-based compound semiconductor layer bonded to the p-type GaN-based compound semiconductor layer, and an active layer, the p-type GaN-based compound semiconductor layer or the n-type GaN-based compound semiconductor layer.
And a GaNP layer formed by performing a heat treatment after ion implantation of As or P into the p-type GaN-based compound semiconductor layer. It is characterized in that the composition ratio of the GaNAs layer or the GaNP layer is different.

According to the present invention, a GaNAs layer or a GaNP layer which is sufficiently mixed with As or P by heating after ion implantation, the p-type GaN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer Since a plurality of light-emitting portions are provided so that the composition ratio of the GaNAs layer or the GaNP layer is different from each other, an LED that emits a plurality of colors in one element can be provided.

Further, the invention according to claim 3 is based on claim 2
3. The GaN-based light-emitting device according to item 1, wherein the three light-emitting units are stacked and provided, and the three
The s layer or the GaNP layer is formed with a composition ratio of emitting blue, green, and red light, respectively.

According to the present invention, since the GaNAs layer or the GaNP layer is formed in the three light emitting portions stacked so as to emit blue, green and red light, respectively, so that one element has three primary colors. An LED that independently emits blue, green, and red light can be provided.

Further, according to a fourth aspect of the present invention, a p-type Ga
An N-based compound semiconductor layer, an n-type GaN-based compound semiconductor layer bonded to the p-type GaN-based compound semiconductor layer, and an active layer, the p-type GaN-based compound semiconductor layer or the n-type GaN-based compound semiconductor layer.
A plurality of GNAs layers or GNP layers formed by performing a heat treatment after ion-implanting As or P into a plurality of regions having different depths into the p-type GaN-based compound semiconductor layer;
And the plurality of GaNAs layers or Ga
The composition ratios of the NP layers are different from each other.

According to the present invention, the GaNAs layer or the GaNP layer which is sufficiently mixed with As or P by heating after ion implantation is replaced with the p-type GaN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer. Since the LEDs are formed at a plurality of different depths and have different composition ratios from each other, it is possible to provide an LED that simultaneously emits a plurality of different colors in one device.

Further, the invention according to claim 5 is based on claim 4
3. The GaN-based light-emitting device according to (1), wherein the three GaNAs layers or the GaNP layers are provided, and the three GaNas layers or the GaNP layers are formed with composition ratios of emitting blue, green, and red, respectively. .

According to the present invention, three G layers serving as active layers are formed.
In the aNAs layer or the GNP layer, blue,
The GNAs layer or G has a composition ratio that emits green and red light.
Since the aNP layer is formed, it is possible to provide an LED that simultaneously emits three primary colors of blue, green, and red in one element, that is, a white light emitting LED.

The invention according to claim 6 is based on claim 1.
In the GaN-based light-emitting device according to any one of the above-described items 5, the InAs (In) is ion-implanted together with the As or P to form the GaNAs layer or Ga.
GaInNAs layer or Ga formed instead of NP layer
It is characterized by having an InNP layer.

According to the present invention, a GaInNAs layer or a GaInNP layer is provided with As or As on either one of a pn-junction p-type GaN-based compound semiconductor layer and an n-type GaN-based compound semiconductor layer. P and I
Since n is formed by heating after ion implantation, A
GaInNAs sufficiently mixed with s or P and In
A layer or a GaInNP layer can be provided as the active layer of the LED.

The invention according to claim 7 is a step of forming the p-type or n-type first GaN-based compound semiconductor layer, and the step of forming the second GaN-based compound semiconductor layer having a conductivity type different from that of the first GaN-based compound semiconductor layer. A step of forming a GaN-based compound semiconductor layer, a step of implanting As or P into the second GaN-based compound semiconductor layer, and a step of subjecting the second GaN-based compound semiconductor layer to a heat treatment to form a GaNAs layer or a GaNP layer. And forming a.

According to the present invention, the p-type G having a pn junction
As or P is ion-implanted into either one of the aN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer and then heated, whereby G serving as an active layer is formed.
Since the aNAs layer or the GNP layer is formed, As
In a state where P or P is sufficiently confined in the GaN-based compound semiconductor layer, GaNAs or GaNP can be mixed-crystallized.

The invention according to claim 8 is a step of forming the p-type or n-type first GaN-based compound semiconductor layer, and the step of forming the second GaN-based compound semiconductor layer having a conductivity type different from that of the first GaN-based compound semiconductor layer. Forming a GaN-based compound semiconductor layer of
As or P and I are added to the second GaN-based compound semiconductor layer.
n ion implantation, and heat-treating the second GaN-based compound semiconductor layer to form a GaN InAs layer or Ga
Forming a NInP layer.

According to the present invention, the p-type G having the pn junction
By ion-implanting As, P, and In into one of the GaN-based compound semiconductor layers of the aN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer and then heating, a GaNInAs layer or a GaNInP layer serving as an active layer is formed. GaNInAs or Ga in a state where As or P and In are sufficiently confined in the GaN-based compound semiconductor layer
NInP can be mixed-crystallized.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a GaN-based light emitting device and a method of manufacturing the same according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

(Embodiment 1) First, a GaN-based light emitting device according to Embodiment 1 and a method for manufacturing the same will be described. In particular, the first embodiment is based on the MOMBE (Metal
-Organic Molecular Beam E
pitaxy) G created by a method according to the method
1 shows an aN-based light emitting device.

FIG. 1 is a sectional view of a GaN-based light emitting device according to the first embodiment. In particular, the GaN-based light emitting device shown in FIG. 1 has an LED structure in which the active layer is made of GaNP. As shown in FIG. 1, the GaN-based light emitting device 100 according to the first embodiment has a pn junction by stacking a p-type GaN layer 14 on an n-type GaN layer 13 having a pn junction. A GaNP layer 15 is formed by ion-implanting P into 14.

An n-type electrode E 1 is formed on the upper surface of the n-type GaN layer 13, and a p-type electrode E 1 is formed on the upper surface of the p-type GaN layer 14.
A mold electrode E2 is formed. Therefore, in the GaN-based light-emitting device 100, when viewed macroscopically, the n-type GaN layer 13 functions as an n-type cladding layer and an n-type low resistance layer, and
The layer 15 functions as an active layer, and the p-type GaN layer 14
It functions as a low resistance layer and a p-type cladding layer, and has a structure in which they are sequentially stacked. That is, the GaN-based light-emitting device 100 has only a structure in which the active layer of the conventional GaN-based light-emitting device is replaced with a GNP layer.
It is characterized by a mixed crystal of aN and P.

Next, the GaN-based light emitting device 1 shown in FIG.
A description will be given of a procedure for creating the 00. FIG. 2 is a flowchart illustrating a procedure for manufacturing the GaN-based light emitting device 100 according to the first embodiment. FIG. 3 is a cross-sectional view for explaining a GaN-based light emitting device created according to the flowchart shown in FIG. Note that an ultra-high vacuum apparatus having a growth chamber and a patterning chamber is used as the MOMBE apparatus.

First, a crystal substrate such as a sapphire substrate, a SiC or silicon substrate is placed on a susceptor in a growth chamber. Here, a sapphire substrate is used as a crystal substrate. Then, in this state, the temperature of the sapphire substrate is maintained at 640 ° C., and the formation of the GaN buffer layer is started (Step S101).

The GaN buffer layer 12 has a vapor pressure of 3 ×
DMH of 10 ^-6 Torr and vapor pressure of 5 × 10 ^-7 Torr
The above-mentioned sapphire substrate 1 is obtained by using each molecular beam of Ga.
1 is obtained as a GaN layer having a thickness of 1000 ° (FIG. 3A).

Subsequently, the substrate temperature is maintained at 850 ° C.
An n-type GaN layer is formed (Step S102). This n-type GaN layer 13 has a vapor pressure of 5 × 10 ⁻⁵ Torr of NH.
₃ , Ga at a vapor pressure of 1 × 10 ⁻⁶ Torr, and a vapor pressure of 6 ×
Using each molecular beam of Si of 10 ^-8 Torr, the above G
On the aN buffer layer 12, a Si-doped thickness of 2 μm
m is obtained as a GaN layer (FIG. 3B).

Then, a p-type GaN layer is further formed thereon (step S103). This p-type GaN layer 14
Is NH _{3 at} a vapor pressure of 5 × 10 ⁻⁵ Torr and a vapor pressure of 5 × 1
Ga of 0 ^-6 Torr and M of vapor pressure 5 × 10 ^-8 Torr
Using a molecular beam of g, a 2,500-mm-thick GaN layer doped with Mg is obtained on the n-type GaN layer 13 (FIG. 3C).

Then, P ions are implanted into the p-type GaN layer 14 (step S104). This ion implantation is performed in the vicinity of the interface between the p-type GaN layer 14 and the n-type GaN layer 13 at, for example, an acceleration energy of 400 keV such that the composition ratio x becomes about 0.95 in the composition formula GaN _x P _1-x . This is done by driving in the amount of P. As a result, P atoms are concentrated and distributed near a certain depth in the p-type GaN layer 14 (FIG. 3D).

In particular, the dose for the ion implantation is a parameter for determining the emission characteristics of the GaNP mixed and crystallized by the heat treatment to be described later, and blue light emission can be obtained with the above dose. That is, by changing the dose based on the composition ratio x described above, a GaN-based light-emitting element having a desired color can be formed.

Immediately after ion implantation,
Many of the defects caused by the implantation and many of the implanted ions are not located at the substitution positions in the crystal lattice and do not function as carriers, and the presence of P is merely a factor of high resistance. That is, in this state, P and GaN of the p-type GaN layer are not mixed crystals, and no GNP is formed. Therefore, a heat treatment is performed to eliminate the defects and perform the mixed crystal formation (step S105).

FIG. 4 is a diagram showing a schematic configuration of a high-pressure heat treatment apparatus for performing a heat treatment. In the high-pressure heat treatment apparatus 20 shown in FIG. 4, first, the substrate in the state shown in FIG. 3D is set on the sample stage 22 fixed in the quartz tube 23. Then, in this state, the inside of the container is heated to 1200 to 1500 ° C.
A nitrogen pressure of 5 atm is applied. The heat treatment time is about 5 minutes.

As a result, in the prior art, when trying to grow a GaNP thin film with each molecular beam of PH ₃ and NH ₃ , the difficulty of migration of P has been a problem. According to the method according to the first aspect, since the ion-implanted P is confined in the GaN layer, sufficient migration becomes possible,
Further, the applied heat energy causes the GNP layer 15
(In this case, mixed crystal of p-type GANP) is realized (FIG. 3E).

Upon completion of the mixed crystal formation of the GaNP, an electrode is formed on the laminated film (step S106). In order to form the electrodes, first, the laminated substrate is moved to a patterning chamber, and SiO ₂ or the like is deposited on the surface thereof using, for example, a plasma CVD apparatus, and is etched and patterned using a photoresist and dry etching. In this case, the above-described n-type GaN layer 1
3 is partially etched, and Ti / Al
The n-type electrode E1 is formed by vapor-depositing such a metal. On the other hand, the p-type electrode E2 is
Is formed by evaporating a metal such as Au / Ni on the upper surface of the substrate.

FIG. 5 is experimental data showing the relationship between the light emission characteristics obtained for a predetermined dose and the heat treatment conditions. FIG. 5 shows that the dose of P is 5 × 10 ^20.
It shows the PL (photoluminescence) intensity obtained when the range is from cm ⁻³ to 1 × 10 ²² cm ⁻³ .
When ion implantation was performed by specifying several doses within the range of the dose, it was found that
PL peaks were confirmed at 50 nm, 550 nm, and 580 nm. In FIG. 5, 390 nm, 450 n
m, the value shown for each of 550 nm is 5
The ratio divided by the peak intensity at 80 nm is shown. That is, it was confirmed that, even in the formation of GaNP by ion implantation, it is possible to produce an LED having a desired color by changing the dose.

As described above, according to the GaN-based light emitting device according to the first embodiment, when the GaN-based light emitting device is manufactured according to the MOMBE method, the n-type GaN
After forming a pn junction by the layer 13 and the p-type GaN layer 14, near the junction interface and in the p-type GaN layer,
P atoms are ion-implanted and then heat-treated to obtain G
Since the mixed crystal of aNP is performed, it is possible to obtain GaNP which is difficult to form a mixed crystal by adding P in a gas phase, with sufficiently high luminous efficiency and the like. In particular, by controlling the dose of P, an LED having a desired color can be obtained from the characteristics of the LED having the active layer of GaNP.

(Embodiment 2) Next, a GaN-based light emitting device according to Embodiment 2 and a method of manufacturing the same will be described. The LED described in the first embodiment is a device that emits light of only one color determined by ion implantation at a predetermined dose, whereas the GaN-based light emitting device according to the second embodiment is shown in FIG. N-type Ga shown in
The method is characterized in that the formation of the N layer 13, the p-type GaN layer 14, and the ion-implanted layer is sequentially repeated, and thereafter, heat treatment is performed to form three independent GaNP active layers in one device.

FIG. 6 is a sectional view of a GaN-based light emitting device according to the second embodiment. GaN-based light emitting device 2 shown in FIG.
Reference numeral 00 denotes a GaN buffer layer 32, an n-type GaN layer 33, and a p-type G
aN layer 34, insulating layer 41, n-type GaN layer 35, p-type Ga
N layer 36, insulating layer 42, n-type GaN layer 37 and p-type G
The aN layer 38 is formed by lamination.

Further, a first dose of P is ion-implanted into the p-type GaN layer 34 near the interface between the n-type GaN layer 33 and the p-type GaN layer 34, and the n-type GaN layer 35 and the p-type GaN A second dose of P is ion-implanted into the p-type GaN layer 36 near the interface of the layer 36 to form the n-type GaN layer 3.
A third dose of P is ion-implanted into the p-type GaN layer 38 near the interface between the p-type GaN layer 38 and the p-type GaN layer 38. By subjecting these to heat treatment, GaN is implanted in each ion-implanted layer.
P layers 51, 52 and 53 are formed.

That is, the GaN-based light emitting device 200 has n
-Type GaN layer 33, GaNP layer 51 and p-type GaN layer 3
5 constitutes a first light emitting unit, and an n-type GaN layer 35;
The second light emitting section is constituted by the GaNP layer 52 and the p-type GaN layer 36, and the third light emitting section is constituted by the n-type GaN layer 37, the GaNP layer 53 and the p-type GaN layer 38.

In particular, the above-mentioned first to third doses are different from each other and are determined by the composition ratio corresponding to the color desired to emit light in each of the GANP layers. For example, in the composition formula GaN _x P _1-x , when it is desired that the GaNP layer 51 function as an active layer that emits blue light, the first dose is set so that the composition ratio x becomes a value near 0.95. And Ga
When the NP layer 52 is desired to function as an active layer that emits green light, the second dose is set so that the composition ratio x becomes a value near 0.90, and the GNP layer 53 is an active layer that emits red light. If you want to function as a third dose,
The amount is such that the composition ratio x has a value near 0.87. That is, in the example of the doping amount, the GaN-based light emitting device 200
Will have three independent active layers that allow each element to emit RGB light.

The GaN-based light emitting device 200 shown in FIG.
In the same manner as in the first embodiment, after patterning by photoresist and dry etching, a metal is evaporated, so that the n-type GaN layer 33, the p-type GaN layer 34, the n-type GaN layer 35, N on the GaN layer 36
N-type GaN layer 37 and p-type GaN layer 38
A type electrode E11, a p-type electrode E12, an n-type electrode E21, a p-type electrode E22, an n-type electrode E31 and a p-type electrode E32 are formed.

Thus, in the first light emitting section, n
By applying a voltage between the type electrode E11 and the p-type electrode E12, in the second light emitting unit, by applying a voltage between the n-type electrode E21 and the p-type electrode E22, n is applied in the third light emitting unit. By applying a voltage between the pattern electrode E31 and the p-type electrode E32, light emission can be controlled independently of each other.

Therefore, in particular, an insulating layer 41 is formed between the first light emitting section and the second light emitting section, and an insulating layer 42 is formed between the second light emitting section and the third light emitting section. Is formed.
That is, each light emitting portion that emits light having a different emission wavelength can function independently with the insulating layer interposed therebetween. As the insulating layers 41 and 42 having such a function, for example, C-doped GaN, high-resistance diamond, diamond-like carbon, or Al
N or the like. Note that each of the n-type G
The method for forming the aN layer, the p-type GaN layer, and the GANP layer includes:
Since it is the same as the first embodiment, the description is omitted here.

In the second embodiment, the first to third embodiments
Are controlled in order to be blue, green, and red, but the order is not particularly limited.

As described above, according to the GaN-based light emitting device according to the second embodiment, the n-type GaN layer and the p-type G
P atoms are ion-implanted in the vicinity of the junction interface with the aN layer and in the p-type GaN layer, and then heat treatment is performed.
The light-emitting portion in which aNP was mixed was sequentially formed on insulating layers 41 and 4.
2 are interposed and stacked, and three light-emitting portions each having a GNP as an active layer are provided. By controlling the doses of P to be different from each other when mixing GNP in each light-emitting portion, Thus, it is possible to obtain an independent LED capable of three different colors.

In particular, the three light emitting portions of the GNP layers 51, 5
By controlling the dose so that the light emission of 2 and 53 becomes the three primary colors of blue, green, and red, full-color light emission can be realized with one GaN-based light-emitting element 200.
In particular, in this case, white light emitting LED
Can be realized.

(Embodiment 3) Next, a GaN-based light emitting device according to Embodiment 3 and a method of manufacturing the same will be described. Embodiment 3 is characterized in that three active layers ion-implanted with different doses from each other are provided in one p-type GaN layer.

FIG. 7 is a sectional view of a GaN-based light emitting device according to the third embodiment. In particular, the GaN-based light emitting device shown in FIG. 7 has an LED structure in which the active layer is made of GaNP. As shown in FIG. 7, the GaN-based light emitting device 300 according to the third embodiment has a pn junction by stacking a p-type GaN layer 64 on an n-type GaN layer 63 having a pn junction.
In the p-type GaN layer 64, three GaNP layers 71, 72 and 73 are formed by ion-implanting P at three different depths. An n-type electrode E51 is formed on the upper surface of the n-type GaN layer 63, and a p-type electrode E52 is formed on the upper surface of the p-type GaN layer 64.

Next, the GaN-based light emitting device 3 shown in FIG.
A description will be given of a procedure for creating the 00. FIG. 8 is a flowchart illustrating a procedure for manufacturing the GaN-based light emitting device 300 according to the third embodiment. FIGS. 9 and 10 are cross-sectional views illustrating a GaN-based light emitting device created according to the flowchart shown in FIG. In addition, MOMB
As the E apparatus, an ultrahigh vacuum apparatus having a growth chamber and a patterning chamber is used.

First, a sapphire substrate serving as a crystal substrate is set on a susceptor in a growth chamber. In this state, the temperature of the sapphire substrate is maintained at 640 ° C.
The formation of the buffer layer is started (Step S201). The GaN buffer layer 62 is obtained in the same procedure as the GaN buffer layer 12 shown in the first embodiment (FIG. 9).
(A)).

Subsequently, the substrate temperature is maintained at 850 ° C.
An n-type GaN layer is formed (Step S202). This n-type GaN layer 63 is also the same as n-type G
It is obtained in the same procedure as for the aN layer 13 (FIG. 9B).

Then, a p-type GaN layer is further formed thereon (step S203). This p-type GaN layer 64
Is also obtained by the same procedure as that for the p-type GaN layer 14 shown in the first embodiment (FIG. 9C).

Then, in the p-type GaN layer 64, the first
P ions serving as a layer are implanted (Step S20)
4). This ion implantation is performed with the p-type GaN layer 14 and the n-type Ga
Near the interface of the N layer 13, an acceleration energy of 200 keV
At 400 keV, the composition ratio x in the composition formula GaN _x P _1- x
Of dose (blue light emission) such that is approximately 0.95
It is done by typing. Thus, the P atom becomes p
From the upper surface of the p-type GaN layer 14, for example, it is concentrated and distributed in the vicinity of a depth of 250 nm (FIG. 9D).

In this state, the p-type GaN layer 6
During P4, ion implantation of P serving as a second layer is performed (step S205). This ion implantation is performed in the vicinity of the upper surface of the first layer, at an acceleration energy of 100 keV to 150 keV.
At keV, the composition ratio x in the composition formula GaN _x P _{1 -x} is 0.
This is performed by implanting a dose of P (green light emission) near 90. Thereby, the P atom becomes p-type Ga
From the upper surface of the N layer 14, for example, it is concentrated and distributed in the vicinity of a depth of 150 nm (FIG. 10E).

Further, in the p-type GaN layer 64,
P ion serving as the third layer is implanted (step S
206). This ion implantation is performed in the vicinity of the upper surface of the second layer at a dose of 50 keV to 80 keV so that the composition ratio x becomes about 0.87 in the composition formula GaN _x P _1-x (red emission). This is done by typing P. As a result, P atoms are concentrated and distributed from the upper surface of the p-type GaN layer 14 to, for example, a depth of about 50 nm (FIG. 10F).

As a result, in the same p-type GaN layer 64,
Ion-implanted layers having different depths and doses are formed. Then, in this state, as in the first embodiment, heat treatment for eliminating defects and performing mixed crystal formation is performed (step S207).

With the thermal energy given by this heat treatment, GaN is formed in the first to third layers, respectively.
Crystallization of P71, 72 and 73 (in this case, p-type G
aNP) is realized (FIG. 10 (g)).

When the mixed crystal of GaNP is completed in this way, an electrode is formed on the laminated film (step S208). This electrode preparation is also the same as that of the first embodiment, and the description thereof is omitted here. That is, the n-type electrode E51 is formed by depositing a metal such as Ti / Al on the upper surface of the n-type GaN layer 63, and the p-type electrode is deposited by depositing a metal such as Au / Ni on the upper surface of the p-type GaN layer 64. The electrode E52 is formed.

In the third embodiment, the dose is controlled so as to be blue, green, and red in the first to third layers, which are ion-implanted layers, respectively. However, the order is not particularly limited. .

As described above, according to the GaN-based light emitting device according to the third embodiment, a pn junction is formed by the n-type GaN layer 63 and the p-type GaN layer 64 when manufacturing the GaN-based light emitting device. After that, three ion implantation layers having different doses are formed in the p-type GaN layer.
By performing the heat treatment, the three GaNP layers 71, 72, and 73 are mixed and crystallized, so that the effects obtained by the first embodiment can be enjoyed and the three GaNP layers 7 can be obtained.
By controlling the dose so that the light emission of 1, 72, and 73 becomes blue, green, and red, an LED that can emit white light with one element and a pair of electrodes can be realized.

In the first to third embodiments, P ions are implanted into the p-type GaN layer. However, an n-type GaN layer is laminated on the p-type GaN layer, and ion implantation is performed on the n-type GaN layer side. You may make it.

Although the case where the active layer is made of GaNP is shown, GaNAs can be mixed-crystallized by ion-implanting As and then heat-treating the same. In addition to GaNaAs, InIn is ion-implanted together with P and As to obtain GaInN.
The present invention can be applied to a case where another GaN-based multi-element mixed crystal film such as P or GaInNAs is used as an active layer.

Further, by simultaneously implanting ions of Mg and Si as dopants as raw materials for forming the active layer, an active layer having a controlled n-type or p-type doping ratio can be formed.

In addition to MOMBE, MOCVD, plasma CVD, or a chloride-based material using a chloride such as gallium chloride or a halide using a hydride may be used as the vapor phase growth method described in the first to third embodiments. A system vapor phase growth method can also be employed.

[0086]

According to the first aspect of the present invention, as described above, the GaN layer or the GaN layer is formed by a pn layer.
Since As or P is ion-implanted into one of the joined p-type GaN-based compound semiconductor layer and n-type GaN-based compound semiconductor layer and then heated, As or P is used. GaN sufficiently mixed with P
There is an effect that the As layer or the GaNP layer can be obtained as an active layer having sufficiently large luminous efficiency.

According to the second aspect of the invention, a GaNAs layer or a GaNP layer sufficiently mixed with As or P by heating after ion implantation, the p-type GaN-based compound semiconductor layer and the n-type And a plurality of light-emitting portions composed of a GaN-based compound semiconductor layer so that the composition ratio of the GaNAs layer or the GNP layer is different from each other, so that a plurality of colors can be emitted in one device. To play.

According to the third aspect of the present invention, in the three light emitting portions stacked, the GaNAs layer or the GANP layer is formed at a composition ratio that emits blue, green, and red light, respectively. The effect is that the three primary colors blue, green and red can be independently emitted from one element.

According to the fourth aspect of the present invention, a GaNAs layer or a GaNP layer sufficiently mixed with As or P by heating after ion implantation is replaced with the p-type GaN-based compound semiconductor layer and n layer. Since the element type GaN-based compound semiconductor layer is formed at a plurality of different depths and has different composition ratios from each other, it is possible to simultaneously emit a plurality of different colors in one device.

Further, according to the fifth aspect of the present invention, the three GaNAs layers or the GaNP layers serving as the active layers have Ga, Ga, and Ga in a composition ratio that emits blue, green, and red light, respectively.
Since the NAs layer or the GANP layer is formed, the three primary colors blue, green, and red can be simultaneously emitted in one element, and white light can be emitted.

According to the sixth aspect of the present invention, G
The aInNAs layer or the GaInNP layer is heated after As or P and In are ion-implanted into one of the pn-junction p-type GaN-based compound semiconductor layer and the n-type GaN-based compound semiconductor layer. Therefore, there is an effect that a GaInNAs layer or GaInNP layer sufficiently mixed with As or P and In can be obtained as an active layer having sufficiently large luminous efficiency.

According to the seventh aspect of the present invention, p
N-type p-type GaN-based compound semiconductor layer and n-type GaN
Since As or P is ion-implanted into one of the GaN-based compound semiconductor layers and then heated to form a GaNAs layer or a GNP layer serving as an active layer, As or P is converted to GaN. It is possible to form a mixed crystal of GaNAs or GaNP in a state where the active layer is sufficiently confined in the system compound semiconductor layer, and it is possible to obtain an active layer having high luminous efficiency.

According to the eighth aspect of the present invention, p
N-type p-type GaN-based compound semiconductor layer and n-type GaN
As or P and In are ion-implanted into one of the GaN-based compound semiconductor layers among the GaN-based compound semiconductor layers and then heated, so that a GaN InAs layer or a GaN
Since the InP layer is formed, As or P and In
GaN with sufficient confinement in the aN-based compound semiconductor layer
It is possible to mix InAs or GaN InP, and it is possible to obtain an active layer with high luminous efficiency.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a GaN-based light emitting device according to a first embodiment.

FIG. 2 is a flowchart illustrating a procedure for manufacturing the GaN-based light emitting device according to the first embodiment.

FIG. 3 is a cross-sectional view for explaining a GaN-based light-emitting device manufactured according to the method for manufacturing a GaN-based light-emitting device according to the first embodiment.

FIG. 4 is a diagram showing a schematic configuration of a high-pressure heat treatment apparatus for performing a heat treatment in the method of manufacturing a GaN-based light emitting device according to the first embodiment.

FIG. 5 is experimental data showing the relationship between the light emission characteristics obtained for a predetermined dose and the heat treatment conditions in the GaN-based light emitting device according to the first embodiment.

FIG. 6 is a cross-sectional view illustrating a configuration of a GaN-based light emitting device according to a second embodiment.

FIG. 7 is a cross-sectional view illustrating a configuration of a GaN-based light emitting device according to a third embodiment.

FIG. 8 is a flowchart showing a procedure for producing a GaN-based light emitting device according to the third embodiment.

FIG. 9 is a cross-sectional view for explaining a GaN-based light-emitting device manufactured according to the method for manufacturing a GaN-based light-emitting device according to the third embodiment.

FIG. 10 is a cross-sectional view for explaining a GaN-based light emitting device manufactured according to the method for manufacturing a GaN-based light emitting device according to the third embodiment.

[Explanation of symbols]

11, 31, 61 Sapphire substrate 12, 32, 62 GaN buffer layer 13, 33, 35, 37, 63 n-type GaN layer 14, 34, 36, 38, 64 p-type GaN layer 15, 51, 52, 53, 71 , 72,73 GaNP
Layers E1, E11, E21, E31, E51 n-type electrode E2, E12, E22, E32, E52 p-type electrode

Claims (8)

[Claims] A p-type GaN-based compound semiconductor layer; and an n-type Ga bonded to the p-type GaN-based compound semiconductor layer.
The N-type compound semiconductor layer and the active layer are formed by performing a heat treatment after ion-implanting As (arsenic) or P (phosphorus) into the p-type GaN-based compound semiconductor layer or the n-type GaN-based compound semiconductor layer. A GaN-based light-emitting device, comprising: a GaNAs layer or a GaNP layer. 2. A p-type GaN-based compound semiconductor layer, and an n-type Ga bonded to the p-type GaN-based compound semiconductor layer.
An N-based compound semiconductor layer, and a GaNA formed by performing a heat treatment after ion-implanting As or P into the p-type GaN-based compound semiconductor layer or the n-type GaN-based compound semiconductor layer as an active layer.
A GaN-based light-emitting device, comprising: a plurality of light-emitting portions each comprising: an s layer or a GaNP layer; and a composition ratio of the GaNAs layer or the GaNP layer is different among the plurality of light-emitting portions. 3. The light emitting unit according to claim 3, wherein three light emitting units are stacked, and in the three light emitting units, the GaNAs layer or the GaNP layer is formed with a composition ratio of emitting blue, green, and red light, respectively. The GaN-based light emitting device according to claim 2. 4. A p-type GaN-based compound semiconductor layer; and n-type Ga bonded to the p-type GaN-based compound semiconductor layer.
Performing heat treatment after ion-implanting As or P into the p-type GaN-based compound semiconductor layer or the n-type GaN-based compound semiconductor layer as an active layer into a plurality of regions having different depths; GaNAs layers or GaNPs formed by
A plurality of GaNAs layers or Ga layers.
GaN having different composition ratios of NP layers
System light emitting element. 5. The semiconductor device according to claim 1, further comprising three GaNas layers or GaNP layers, wherein the three GaNas layers or GaNP layers are:
The GaN-based light-emitting device according to claim 4, wherein the GaN-based light-emitting device is formed with a composition ratio of emitting blue, green, and red light, respectively. 6. A GaInNAs layer or a GaInNP layer formed in place of the GaNAs layer or the GaNP layer by implanting In (indium) ions together with the As or P. 6. The GaN-based light emitting device according to any one of 1 to 5. 7. A step of forming a p-type or n-type first GaN-based compound semiconductor layer, and forming a second GaN-based compound semiconductor layer having a conductivity type different from that of the first GaN-based compound semiconductor layer. A step of ion-implanting As or P into the second GaN-based compound semiconductor layer;
forming a aNAs layer or a GaNP layer. A method for producing a GaN-based light-emitting device, comprising: 8. A step of forming a p-type or n-type first GaN-based compound semiconductor layer; and forming a second GaN-based compound semiconductor layer having a conductivity type different from that of the first GaN-based compound semiconductor layer. And As or P and I in the second GaN-based compound semiconductor layer.
ion-implanting n; heat-treating the second GaN-based compound semiconductor layer to obtain a G
forming a aNInAs layer or a GaNInP layer.