阅读说明：本技术 一种氮化物近红外发光二极管的制备方法 (Preparation method of nitride near-infrared light-emitting diode ) 是由 杨帆 王超 王艳杰 吴博琦 闫兴振 王欢 高晓红 吕卅 杨佳 赵春雷 赵阳 迟 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种氮化物近红外发光二极管的制备方法,包括如下步骤：步骤一、在蓝宝石衬底上制备外延结构层；其中,所述外延结构层依次包括：GaN成核层、GaN模板层、DBR反射层、p型InGaN空穴注入层和n-InN发光层；步骤二、将所述外延结构层表面的部分n-InN发光层刻蚀掉,得到多个电极沉积区域,其中,所述电极沉积区域对应的p型InGaN空穴注入层暴露出来；步骤三、在所述电极沉积区域沉积第一金属电极并退火,形成p型区电极；步骤四、在所述n-InN发光层上沉积第二金属电极并退火,得到初级器件；步骤五、对所述初级器件进行解理、封装,得到分立的发光二极管器件。(The invention discloses a preparation method of a nitride near-infrared light-emitting diode, which comprises the following steps: step one, preparing an epitaxial structure layer on a sapphire substrate; wherein, epitaxial structure layer includes in proper order: the GaN-based light emitting diode comprises a GaN nucleating layer, a GaN template layer, a DBR reflecting layer, a p-type InGaN hole injection layer and an n-InN light emitting layer; etching part of the n-InN light emitting layer on the surface of the epitaxial structure layer to obtain a plurality of electrode deposition areas, wherein the p-type InGaN hole injection layer corresponding to the electrode deposition areas is exposed; depositing a first metal electrode in the electrode deposition area and annealing to form a p-type area electrode; depositing a second metal electrode on the n-InN light-emitting layer and annealing to obtain a primary device; and fifthly, cleaving and packaging the primary device to obtain a discrete light-emitting diode device.)

1. A preparation method of a nitride near-infrared light-emitting diode is characterized by comprising the following steps:

step one, preparing an epitaxial structure layer on a sapphire substrate;

wherein, epitaxial structure layer includes in proper order: the GaN-based light emitting diode comprises a GaN nucleating layer, a GaN template layer, a DBR reflecting layer, a p-type InGaN hole injection layer and an n-InN light emitting layer;

etching part of the n-InN light-emitting layer on the surface of the epitaxial structure layer to obtain a plurality of electrode deposition areas,

the p-type InGaN hole injection layer corresponding to the electrode deposition area is exposed;

depositing a first metal electrode in the electrode deposition area and annealing to form a p-type area electrode;

depositing a second metal electrode on the n-InN light-emitting layer and annealing to obtain a primary device;

and fifthly, cleaving and packaging the primary device to obtain a discrete light-emitting diode device.

2. The method of claim 1, wherein the GaN nucleation layer is grown from TEGa and NH₃(ii) a The growth temperature is 500-600 ℃, the pressure is 500-700 mbar, the TEGa flow is 25-45 mu mol/min, and NH is₃The flow rate is 500-2000 sccm.

3. The method of claim 2, wherein the GaN template layer is grown from TMGa and NH₃(ii) a The growth temperature is 900-1100 ℃, the pressure is 200-500 mbar, the TMGa flow is 40-70 mu mol/min, NH₃The flow rate is 1000-4000 sccm.

4. The method of manufacturing a nitride near-infrared light emitting diode according to claim 2 or 3, wherein the DBR reflection layer includes a plurality of InGaN layers and GaN layers alternately arranged;

wherein the In content of the InGaN layer is 10-40%, and the growth sources of the InGaN layer are TMIn, TEGa and NH₃(ii) a The growth temperature of InGaN is 600-850 deg.C, the pressure is 300-500 mbar, the flow rate of TMIn is 3-6 mu mol/min, the flow rate of TEGa is 1-5 mu mol/min, NH₃The flow rate is 3000-7000 sccm;

the growth source of the GaN layer is TEGa and NH₃(ii) a The growth temperature of the GaN layer is 600-850 ℃, the pressure is 300-500 mbar, the TEGa flow is 10-45 mu mol/min, and NH is₃The flow rate is 3000-7000 sccm.

5. The method according to claim 4, wherein the thickness of each InGaN layer is 100-300 nm; the thickness of each GaN layer is 100-300 nm.

6. The method of claim 5, wherein the p-type InGaN hole injection layer is grown with Cp as a source₂Mg and NH₃The growth temperature of the p-type InGaN hole injection layer is 600-850 ℃, the pressure is 300-500 mbar, the flow rate of TMIn is 2-8 mu mol/min, the flow rate of TEGa is 1-5 mu mol/min, Cp₂Mg flow rate of 0.1 to 1 [ mu ] mol/min, NH₃The flow rate is 3000-7000 sccm.

7. The method for preparing a nitride near-infrared light-emitting diode according to claim 6, wherein the thickness of the p-type InGaN hole injection layer is 1-3 μm.

8. The method as claimed in claim 7, wherein the InN light-emitting layer is grown from TMIn and NH₃(ii) a The growth temperature of the InN light-emitting layer is 500-600 ℃, the pressure is 400-800 mbar, the TMIn flow is 3-10 mu mol/min, and NH is₃The flow rate is 5000-9000 sccm.

9. The method according to claim 8, wherein in the third step, the first metal electrode is deposited using an electrode material selected from the group consisting of: simple substance materials of Au and Ni, binary alloy materials of Ni-Au, Ti-Au, Zn-Au and Pt-Au or ternary alloy materials of Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au.

10. The method according to claim 9, wherein in the fourth step, the second metal electrode is deposited using an electrode material selected from the group consisting of: simple substance materials of Au and Ni, binary alloy materials of Ni-Au, Ti-Au, Zn-Au and Pt-Au or ternary alloy materials of Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au.

Technical Field

The invention belongs to the technical field of light emitting diode preparation, and particularly relates to a preparation method of a nitride near-infrared light emitting diode.

Background

Group III nitride materials are typical representatives of third generation wide bandgap semiconductor materials, including aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN) and alloys thereof, and are currently widely used in the field of optoelectronic devices. The material of the system can enable the forbidden bandwidth of the material to be continuously adjustable from 0.7eV (InN) to 6.2eV (AlN) by adjusting the content of the III group element, and the corresponding wavelength covers a wide spectral range (200-1700 nm) from ultraviolet to near infrared, so that the III group nitride has incomparable advantages as a luminescent material.

At present, in the field of infrared LEDs, materials such as GaAs and InP have excellent performance, but V group elements in III-V group semiconductor materials have high toxicity, such as P, As, and the like, so that the application range of the materials is limited. And the III group nitride does not contain highly toxic elements, and has the advantages of high efficiency, energy conservation, safety, environmental protection and the like. In recent years, researchers have developed several InN-based heterojunction electroluminescent devices with emission peaks around 1600 nm. These devices are based on simple p-n junction light emitting devices, and since the light emission direction is random, a large proportion of the infrared light is emitted from the substrate side and is not utilized efficiently. In addition, for an n-InN/p-GaN heterojunction device, the p-GaN is doped with Mg generally, and the acceptor activation energy of Mg in GaN is larger and about 200meV, so that the doping efficiency is low, the hole concentration of a p-type material is not high, the hole injection efficiency of the heterojunction device is reduced, and the light emitting performance is influenced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of a nitride near-infrared light-emitting diode, which can improve the light extraction efficiency of a device.

Compared with p-GaN, the p-type InGaN hole injection layer has narrower forbidden band width, reduces the acceptor activation energy of Mg, can improve the hole concentration of a p-type material, and then improves the hole injection efficiency of a p-n junction.

The technical scheme provided by the invention is as follows:

a method for preparing a nitride near-infrared light-emitting diode comprises the following steps:

step one, preparing an epitaxial structure layer on a sapphire substrate;

wherein, epitaxial structure layer includes in proper order: the GaN-based light emitting diode comprises a GaN nucleating layer, a GaN template layer, a DBR reflecting layer, a p-type InGaN hole injection layer and an n-InN light emitting layer;

etching part of the n-InN light-emitting layer on the surface of the epitaxial structure layer to obtain a plurality of electrode deposition areas,

the p-type InGaN hole injection layer corresponding to the electrode deposition area is exposed;

depositing a first metal electrode in the electrode deposition area and annealing to form a p-type area electrode;

depositing a second metal electrode on the n-InN light-emitting layer and annealing to obtain a primary device;

and fifthly, cleaving and packaging the primary device to obtain a discrete light-emitting diode device.

Preferably, the growth sources of the GaN nucleation layer are TEGa and NH₃(ii) a The growth temperature is 500-600 ℃, the pressure is 500-700 mbar, the TEGa flow is 25-45 mu mol/min, and NH is₃The flow rate is 500-2000 sccm.

Preferably, the GaN template layer has TMGa and NH as growth sources₃(ii) a The growth temperature is 900-1100 ℃, the pressure is 200-500 mbar, the TMGa flow is 40-70 mu mol/min, NH₃The flow rate is 1000-4000 sccm.

Preferably, the DBR reflective layer includes a plurality of InGaN layers and GaN layers alternately arranged;

wherein the In content of the InGaN layer is 10-40%, and the growth sources of the InGaN layer are TMIn, TEGa and NH₃(ii) a The growth temperature of InGaN is 600-850 deg.C, the pressure is 300-500 mbar, the flow rate of TMIn is 3-6 mu mol/min, the flow rate of TEGa is 1-5 mu mol/min, NH₃The flow rate is 3000-7000 sccm;

the growth source of the GaN layer is TEGa and NH₃(ii) a The growth temperature of the GaN layer is 600-850 ℃, the pressure is 300-500 mbar, the TEGa flow is 10-45 mu mol/min, and NH is₃The flow rate is 3000-7000 sccm.

Preferably, the thickness of each InGaN layer is 100-300 nm; the thickness of each GaN layer is 100-300 nm.

Preferably, the growth source of the p-type InGaN hole injection layer is Cp₂Mg and NH₃The growth temperature of the p-type InGaN hole injection layer is 600-850 ℃, the pressure is 300-500 mbar, the flow rate of TMIn is 2-8 mu mol/min, the flow rate of TEGa is 1-5 mu mol/min, Cp₂Mg flow rate of 0.1 to 1 [ mu ] mol/min, NH₃The flow rate is 3000-7000 sccm.

Preferably, the thickness of the p-type InGaN hole injection layer is 1-3 μm.

Preferably, the InN light-emitting layer has TMIn and NH as growth sources₃(ii) a The growth temperature of the InN light-emitting layer is 500-600 ℃, the pressure is 400-800 mbar, the TMIn flow is 3-10 mu mol/min, and NH is₃The flow rate is 5000-9000 sccm.

Preferably, in the third step, the electrode material used for depositing the first metal electrode is: simple substance materials of Au and Ni, binary alloy materials of Ni-Au, Ti-Au, Zn-Au and Pt-Au or ternary alloy materials of Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au.

Preferably, in the fourth step, the electrode material used for depositing the second metal electrode is: simple substance materials of Au and Ni, binary alloy materials of Ni-Au, Ti-Au, Zn-Au and Pt-Au or ternary alloy materials of Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au.

The invention has the beneficial effects that:

according to the preparation method of the nitride near-infrared light-emitting diode, the InGaN/GaN DBR structure is introduced into the InN heterojunction light-emitting device, the emergent light on one side of the substrate is reflected to the upper surface of the sample, and the light extraction efficiency of the device is improved.

Compared with p-GaN, the p-type InGaN hole injection layer has narrower forbidden band width, reduces the acceptor activation energy of Mg, improves the hole concentration of a p-type material, and further improves the hole injection efficiency of a p-n junction so as to achieve the purpose of improving the luminous efficiency of a device.

The preparation method of the nitride near-infrared light-emitting diode provided by the invention is used for preparing the InN heterojunction light-emitting device on the sapphire substrate in a one-time epitaxial manner, and the preparation process is simple and easy to implement.

Drawings

Fig. 1 is a schematic structural diagram of a sample 1 according to the present invention.

Fig. 2 is a schematic structural diagram of a DBR reflective layer according to the present invention.

Fig. 3 is a schematic structural diagram of sample 2 according to the present invention.

Fig. 4 is a schematic structural diagram of sample 3 according to the present invention.

Fig. 5 is a schematic structural diagram of sample 4 according to the present invention.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

As shown in fig. 1 to 5, the present invention provides a method for preparing a nitride near-infrared light emitting diode, which is used for preparing an InGaN-based infrared LED chip structure, the InGaN-based red LED chip structure comprising: a sapphire substrate 100 and an epitaxial structure layer; wherein, epitaxial structure layer include: a GaN nucleation layer (circulation) 210, a GaN template layer (template)220, an InGaN/GaN-based DBR reflective layer 230, a p-type InGaN hole injection layer 240, and an n-InN light emitting layer 250.

The preparation method of the nitride near-infrared light-emitting diode mainly comprises the following steps:

1. a chip structure (epitaxial structure layer) is epitaxially grown on the sapphire substrate 100 in sequence by using an MOCVD method, and the growth sources are trimethyl gallium (TMGa), triethyl gallium (TEGa), trimethyl indium (TMIn) and cyclopentadienyl magnesium (Cp)₂Mg) and high purity ammonia (NH)₃). As shown in fig. 1, the preparation method of the epitaxial structure layer is as follows:

first, a GaN nucleation layer 210 is prepared.

The GaN nucleating layer 210 is arranged on the sapphire substrate 100, the growth temperature of the GaN nucleating layer 210 is 500-600 ℃, the pressure is 500-700 mbar, the TEGa flow is 25-45 mu mol/min, and NH is₃The flow rate is 500-2000 sccm. The thickness of the prepared GaN nucleation layer 210 is 5-50 nm.

② the GaN template layer 220 is prepared.

The GaN template layer 220 is arranged on the GaN nucleating layer 210, the growth temperature of the GaN template layer 220 is 900-1100 ℃, the pressure is 200-500 mbar, the TMGa flow is 40-70 mu mol/min, and NH is₃The flow rate is 1000-4000 sccm. The thickness of the prepared GaN template layer 220 is 1-3 mu m.

Preparing the DBR reflecting layer 230.

The DBR reflective layer 230 is disposed on the GaN template layer 220. As shown in the figure2, each DBR reflection layer 230 is formed by alternately growing InGaN layers 231 and GaN layers 232, each DBR pair is formed by one InGaN layer 231 and one GaN layer 232, the number of pairs of the whole DBR reflection layer is 10, the reflectivity is more than 85%, and the total thickness is 2-5 μm. Wherein the InGaN layer 231 at the bottom is disposed on the GaN template layer 220; the In content In the InGaN layer 231 is 10-40%, the growth temperature of the InGaN layer 231 is 600-850 ℃, the pressure is 300-500 mbar, the TMIn flow rate is 3-6 mu mol/min, the TEGa flow rate is 1-5 mu mol/min, and NH is added₃The flow rate is 3000-7000 sccm, and the thickness of each InGaN layer 231 is 100-300 nm. The growth temperature of the GaN layer 232 is 600-850 ℃, the pressure is 300-500 mbar, the TEGa flow is 10-45 mu mol/min, and NH is₃The flow rate is 3000-7000 sccm, and the thickness of each GaN layer 232 is 100-300 nm.

And preparing the p-type InGaN hole injection layer 240.

A p-type InGaN hole injection layer 240 is disposed on the GaN layer 232 of the DBR reflective layer 230. The growth temperature of the p-type InGaN hole injection layer is 600-850 ℃, the pressure is 300-500 mbar, the flow rate of TMIn is 2-8 mu mol/min, the flow rate of TEGa is 1-5 mu mol/min, and Cp₂Mg flow rate of 0.1 to 1 [ mu ] mol/min, NH₃The flow rate is 3000-7000 sccm. The thickness of the p-type InGaN hole injection layer 240 is 1-3 μm.

Preparing an InN light emitting layer 250.

The InN light emitting layer 250 is disposed on the p-type InGaN hole injection layer 240. The growth temperature of the InN light-emitting layer 250 is 500-600 ℃, the pressure is 400-800 mbar, the TMIn flow is 3-10 mu mol/min, and NH is₃The flow rate is 5000-9000 sccm. The thickness of the prepared InN light-emitting layer 250 is 100-500 nm.

The growth of the epitaxial structure layer is finished, and sample 1 is obtained, as shown in fig. 1.

2. Etching a plurality of electrode deposition areas 240a on the surface of the sample 1 by adopting the processes of photoetching, etching and the like; in which the InN layer corresponding to the electrode deposition region 240a was etched away to expose the p-InGaN layer, resulting in sample 2, as shown in fig. 3.

3. And depositing a first metal electrode on the p-type InGaN layer corresponding to the electrode deposition area 240a of the sample 2 by adopting the processes of photoetching, evaporation or sputtering and the like, and annealing to form a p-type area electrode 310, wherein the thickness of the p-type area electrode 310 is 30-100 nm, so as to obtain a sample 3, as shown in FIG. 4. The electrode material for depositing the first metal electrode can be single substance materials such as Au, Ni and the like or binary alloy materials such as Ni-Au, Ti-Au, Zn-Au, Pt-Au and the like, and can also be ternary alloy materials such as Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au and the like.

4. A second metal electrode 320 is deposited on the InN layer of sample 3 and annealed using photolithography, evaporation, or sputtering. Sample 4 (primary device) was obtained as shown in fig. 5. The material for depositing the second metal electrode 320 may be simple substance material such as Au and Ni, binary alloy material such as Ni-Au, Ti-Au, Zn-Au and Pt-Au, or ternary alloy material such as Ti-Pt-Au, Ti-Ni-Au or Ni-Pt-Au.

5. And cleaving and packaging the sample 4 to obtain the discrete LED device.

According to the preparation method of the nitride near-infrared light-emitting diode, the InGaN/GaN DBR structure is introduced into the InN heterojunction light-emitting device, the emergent light on one side of the substrate is reflected to the upper surface of the sample, and the light extraction efficiency of the device is improved. In addition, the p-type InGaN hole injection layer is arranged, compared with p-GaN, the p-type InGaN hole injection layer is narrower in forbidden bandwidth, acceptor activation energy of Mg is reduced, hole concentration of a p-type material is improved, hole injection efficiency of a p-n junction is improved, and therefore the purpose of improving luminous efficiency of a device is achieved. According to the technical scheme, the InN heterojunction light-emitting device is prepared on the sapphire substrate in a one-time epitaxial mode, and the preparation process is simple and easy to implement.

Example 1

The preparation method of the nitride near-infrared light-emitting diode mainly comprises the following steps:

1. a chip structure (epitaxial structure layer) is epitaxially grown in sequence on the sapphire substrate 100 by the MOCVD method. As shown in fig. 1, the preparation method of the epitaxial structure layer is as follows:

first, a GaN nucleation layer 210 is prepared.

The GaN nucleating layer 210 is arranged on the sapphire substrate 100, the growth temperature of the GaN nucleating layer 210 is 550 ℃, the pressure is 600mbar, the TEGa flow is 37.5 mu mol/min, and NH is₃The flow rate was 1200 sccm. Is prepared byThe GaN nucleation layer 210 is 20nm thick.

② the GaN template layer 220 is prepared.

The GaN template layer 220 is disposed on the GaN nucleation layer 210, the GaN template layer 220 has a growth temperature of 1040 deg.C, a pressure of 300mbar, a TMGa flow of 54.6 [ mu ] mol/min, and NH₃The flow rate was 2900 sccm. The thickness of the prepared GaN template layer 220 is 1.5 μm.

Preparing the DBR reflecting layer 230.

The DBR reflective layer 230 is disposed on the GaN template layer 220. As shown in fig. 2, the DBR reflective layer 230 is composed of InGaN layers 231 and GaN layers 232 alternately grown, each DBR is composed of one InGaN layer 231 and one GaN layer 232, the number of pairs of the entire DBR reflective layer is 10, the reflectivity is more than 85%, and the total thickness is 3.97 μm. Wherein the InGaN layer 231 at the bottom is disposed on the GaN template layer 220; the In composition In the InGaN layer 231 was 30%, the growth temperature of the InGaN layer 231 was 780 ℃, the pressure was 400mbar, the TMIn flow rate was 4.8. mu. mol/min, the TEGa flow rate was 1.5. mu. mol/min, NH₃The flow rate was 6000sccm, and the thickness of each InGaN layer 231 was 212 nm. The growth temperature of the GaN layer 232 is 780 ℃, the pressure is 400mbar, the TEGa flow is 18 mu mol/min, and NH is formed₃The flow rate was 6000sccm, and the thickness of each GaN layer 232 was 185 nm.

And preparing the p-type InGaN hole injection layer 240.

A p-type InGaN hole injection layer 240 is disposed on the GaN layer 232 of the DBR reflective layer 230. The growth temperature of the p-type InGaN hole injection layer is 780 ℃, the pressure is 400mbar, the TMIn flow rate is 4.8 mu mol/min, the TEGa flow rate is 1.5 mu mol/min, and Cp₂Mg flow rate of 0.2. mu. mol/min, NH₃The flow rate was 6000 sccm. The thickness of the prepared p-type InGaN hole injection layer 240 is 1 μm.

Preparing an InN light emitting layer 250.

The InN light emitting layer 250 is disposed on the p-type InGaN hole injection layer 240. The InN light-emitting layer 250 has a growth temperature of 600 deg.C, a pressure of 600mbar, a TMIn flow of 5 μmol/min, and NH₃The flow rate was 8000 sccm. The prepared InN light emitting layer 250 was 200nm thick.

The growth of the epitaxial structure layer is finished, and sample 1 is obtained, as shown in fig. 1.

2. Etching a plurality of electrode deposition areas 240a on the surface of the sample 1 by adopting the processes of photoetching, etching and the like; in which the InN layer corresponding to the electrode deposition region 240a was etched away to expose the p-InGaN layer, resulting in sample 2, as shown in fig. 3.

3. A first metal electrode is deposited on the p-type InGaN layer corresponding to the electrode deposition region 240a of the sample 2 by using the processes of photolithography, evaporation, sputtering, or the like, and annealed to form a p-type region electrode 310, wherein the thickness of the p-type region electrode 310 is 50nm, so as to obtain a sample 3, as shown in fig. 4. Wherein the electrode material for depositing the first metal electrode is Au.

4. A second metal electrode 320 is deposited on the InN layer of sample 3 and annealed using photolithography, evaporation, or sputtering. Sample 4 (primary device) was obtained as shown in fig. 5. Wherein the material for depositing the second metal electrode 320 is Au.

5. And cleaving and packaging the sample 4 to obtain the discrete LED device.

Example 2

The preparation method of the nitride near-infrared light-emitting diode mainly comprises the following steps:

1. a chip structure (epitaxial structure layer) is epitaxially grown in sequence on the sapphire substrate 100 by the MOCVD method. As shown in fig. 1, the preparation method of the epitaxial structure layer is as follows:

first, a GaN nucleation layer 210 is prepared.

A GaN nucleation layer 210 is arranged on the sapphire substrate 100, the growth temperature of the GaN nucleation layer 210 is 500 ℃, the pressure is 700mbar, the TEGa flow is 31.5 mu mol/min, and NH is₃The flow rate was 1500 sccm. The GaN nucleation layer 210 was prepared to a thickness of 45 nm.

② the GaN template layer 220 is prepared.

The GaN template layer 220 is disposed on the GaN nucleation layer 210, the GaN template layer 220 has a growth temperature of 1100 deg.C, a pressure of 500mbar, a TMGa flow of 65.6 [ mu ] mol/min, and NH₃The flow rate was 3500 sccm. The thickness of the prepared GaN template layer 220 is 2.5 μm.

Preparing the DBR reflecting layer 230.

The DBR reflective layer 230 is disposed on the GaN template layer 220. As shown in FIG. 2, the DBR reflective layer 230 is composed of an InGaN layer 231 and a GaN layer232 are alternately grown, each DBR pair is composed of an InGaN layer 231 and a GaN layer 232, the number of pairs of the reflective layers of the whole DBR is 10, the reflectivity is more than 85%, and the total thickness is 4.79 μm. Wherein the InGaN layer 231 at the bottom is disposed on the GaN template layer 220; the In composition In the InGaN layer 231 was 25%, the growth temperature of the InGaN layer 231 was 700 ℃, the pressure was 500mbar, the TMIn flow rate was 5.4. mu. mol/min, the TEGa flow rate was 3.3. mu. mol/min, NH₃The flow rate was 4000sccm and the thickness of each InGaN layer 231 was 256 nm. The growth temperature of the GaN layer 232 is 700 ℃, the pressure is 500mbar, the TEGa flow is 45 mu mol/min, and NH is₃The flow rate was 4000sccm and the thickness of each GaN layer 232 was 223 nm.

And preparing the p-type InGaN hole injection layer 240.

A p-type InGaN hole injection layer 240 is disposed on the GaN layer 232 of the DBR reflective layer 230. The growth temperature of the p-type InGaN hole injection layer is 700 ℃, the pressure is 500mbar, the TMIn flow rate is 5.4 mu mol/min, the TEGa flow rate is 3.3 mu mol/min, and Cp₂Mg flow rate of 0.6. mu. mol/min, NH₃The flow rate was 4000 sccm. The thickness of the p-type InGaN hole injection layer 240 prepared was 2.5 μm.

Preparing an InN light emitting layer 250.

The InN light emitting layer 250 is disposed on the p-type InGaN hole injection layer 240. The InN light-emitting layer 250 has a growth temperature of 500 deg.C, a pressure of 800mbar, a TMIn flow of 7.5 μmol/min, and NH₃The flow rate was 9000 sccm. The prepared InN light emitting layer 250 was 400nm thick.

The growth of the epitaxial structure layer is finished, and sample 1 is obtained, as shown in fig. 1.

2. Etching a plurality of electrode deposition areas 240a on the surface of the sample 1 by adopting the processes of photoetching, etching and the like; in which the InN layer corresponding to the electrode deposition region 240a was etched away to expose the p-InGaN layer, resulting in sample 2, as shown in fig. 3.

3. A first metal electrode is deposited on the p-type InGaN layer corresponding to the electrode deposition region 240a of the sample 2 by using the processes of photolithography, evaporation, sputtering, or the like, and annealed to form a p-type region electrode 310, where the thickness of the p-type region electrode 310 is 100nm, so as to obtain a sample 3, as shown in fig. 4. Wherein, the electrode material for depositing the first metal electrode is a Ni-Au binary alloy material.

4. A second metal electrode 320 is deposited on the InN layer of sample 3 and annealed using photolithography, evaporation, or sputtering. Sample 4 (primary device) was obtained as shown in fig. 5. Wherein, the material for depositing the second metal electrode 320 is a Ni-Au binary alloy material.

5. And cleaving and packaging the sample 4 to obtain the discrete LED device.

Example 3

The preparation method of the nitride near-infrared light-emitting diode mainly comprises the following steps:

1. a chip structure (epitaxial structure layer) is epitaxially grown in sequence on the sapphire substrate 100 by the MOCVD method. As shown in fig. 1, the preparation method of the epitaxial structure layer is as follows:

first, a GaN nucleation layer 210 is prepared.

The GaN nucleating layer 210 is arranged on the sapphire substrate 100, the growth temperature of the GaN nucleating layer 210 is 600 ℃, the pressure is 500mbar, the TEGa flow is 25.5 mu mol/min, and NH is₃The flow rate was 900 sccm. The GaN nucleation layer 210 was prepared to a thickness of 5 nm.

② the GaN template layer 220 is prepared.

The GaN template layer 220 is disposed on the GaN nucleation layer 210, the GaN template layer 220 has a growth temperature of 950 deg.C, a pressure of 200mbar, a TMGa flow of 45.6 [ mu ] mol/min, and NH₃The flow rate was 2000 sccm. The thickness of the prepared GaN template layer 220 is 1 μm.

Preparing the DBR reflecting layer 230.

The DBR reflective layer 230 is disposed on the GaN template layer 220. As shown in fig. 2, the DBR reflective layer 230 is composed of InGaN layers 231 and GaN layers 232 alternately grown, each DBR is composed of one InGaN layer 231 and one GaN layer 232, the number of pairs of the entire DBR reflective layer is 10, the reflectivity is more than 85%, and the total thickness is 2.59 μm. Wherein the InGaN layer 231 at the bottom is disposed on the GaN template layer 220; the In composition In the InGaN layer 231 was 35%, the growth temperature of the InGaN layer 231 was 850 ℃, the pressure was 300mbar, the TMIn flow rate was 3.6. mu. mol/min, the TEGa flow rate was 1.1. mu. mol/min, NH₃The flow rate was 7000sccm and the thickness of each InGaN layer 231 was 138 nm. The growth temperature of the GaN layer 232 is 850 ℃, the pressure is 300mbar, and the TEGa flowThe amount is 10.5. mu. mol/min, NH₃The flow rate was 7000sccm, and the thickness of each GaN layer 232 was 120 nm.

And preparing the p-type InGaN hole injection layer 240.

A p-type InGaN hole injection layer 240 is disposed on the GaN layer 232 of the DBR reflective layer 230. The growth temperature of the p-type InGaN hole injection layer is 850 ℃, the pressure is 300mbar, the TMIn flow rate is 3.6 mu mol/min, the TEGa flow rate is 1.1 mu mol/min, and Cp₂Mg flow 0.1. mu. mol/min, NH₃The flow rate was 7000 sccm. The thickness of the prepared p-type InGaN hole injection layer 240 is 2 μm.

Preparing an InN light emitting layer 250.

The InN light emitting layer 250 is disposed on the p-type InGaN hole injection layer 240. The InN light-emitting layer 250 has a growth temperature of 500 deg.C, a pressure of 400mbar, a TMIn flow of 3.6 μmol/min, and NH₃The flow rate was 5500 sccm. The InN light emitting layer 250 prepared was 100nm thick.

The growth of the epitaxial structure layer is finished, and sample 1 is obtained, as shown in fig. 1.

2. Etching a plurality of electrode deposition areas 240a on the surface of the sample 1 by adopting the processes of photoetching, etching and the like; in which the InN layer corresponding to the electrode deposition region 240a was etched away to expose the p-InGaN layer, resulting in sample 2, as shown in fig. 3.

3. A first metal electrode is deposited on the p-type InGaN layer corresponding to the electrode deposition region 240a of the sample 2 by using the processes of photolithography, evaporation, sputtering, or the like, and annealed to form a p-type region electrode 310, wherein the thickness of the p-type region electrode 310 is 30nm, so as to obtain a sample 3, as shown in fig. 4. Wherein the electrode material for depositing the first metal electrode is a Ti-Ni-Au ternary alloy material.

4. A second metal electrode 320 is deposited on the InN layer of sample 3 and annealed using photolithography, evaporation, or sputtering. Sample 4 (primary device) was obtained as shown in fig. 5. Wherein, the material for depositing the second metal electrode 320 is a Ti-Ni-Au ternary alloy material.

5. And cleaving and packaging the sample 4 to obtain the discrete LED device.

Comparative example

The preparation method of the comparative example infrared light-emitting diode mainly comprises the following steps:

1. a chip structure is epitaxially grown on a sapphire substrate in sequence by adopting an MOCVD method, and the preparation method comprises the following steps:

preparing a GaN nucleating layer.

The GaN nucleating layer is arranged on the sapphire substrate, the growth temperature of the GaN nucleating layer is 550 ℃, the pressure is 600mbar, the TEGa flow is 37.5 mu mol/min, and NH is₃The flow rate was 1200 sccm. The thickness of the prepared GaN nucleating layer is 20 nm.

Preparing the GaN template layer.

The GaN template layer is arranged on the GaN nucleating layer 210, the growth temperature of the GaN template layer is 1040 ℃, the pressure is 300mbar, the TMGa flow is 54.6 mu mol/min, and NH is₃The flow rate was 2900 sccm. The thickness of the prepared GaN template layer is 1.5 mu m.

And preparing a p-type GaN hole injection layer.

The p-type GaN hole injection layer is disposed on the GaN template layer. The growth temperature of the p-type GaN hole injection layer is 780 ℃, the pressure is 400mbar, the TEGa flow is 1.5 mu mol/min, and Cp₂Mg flow rate of 0.2. mu. mol/min, NH₃The flow rate was 6000 sccm. The thickness of the p-type GaN hole injection layer prepared is 1 mu m.

And fourthly, preparing the InN luminous layer.

The InN light emitting layer is arranged on the p-type GaN hole injection layer. The growth temperature of the InN light-emitting layer is 600 ℃, the pressure is 600mbar, the TMIn flow is 5 mu mol/min, and NH is₃The flow rate was 8000 sccm. The thickness of the prepared InN luminescent layer is 200 nm.

2. Etching a plurality of electrode deposition areas on the InN light-emitting layer by adopting the processes of photoetching, etching and the like; wherein, the InN layer corresponding to the electrode deposition area is etched away, so that the p-GaN layer is exposed.

3. And depositing a first metal electrode on the p-type GaN layers corresponding to the electrode deposition areas by adopting the processes of photoetching, evaporation or sputtering and the like, and annealing to form a p-type area electrode, wherein the thickness of the p-type area electrode is 50 nm. Wherein the electrode material for depositing the first metal electrode is Au.

4. And depositing a second metal electrode on the InN layer by adopting the processes of photoetching, evaporation or sputtering and the like, and annealing. A primary device is obtained. Wherein the material for depositing the second metal electrode is Au.

5. And cleaving and packaging the obtained primary device to obtain a discrete LED device.

In examples 1 to 3 and comparative examples, the preparation of an InN heterojunction light-emitting device on a sapphire substrate by one-time epitaxy is realized, and compared with an n-InN/p-GaN heterojunction light-emitting device in the comparative example, an InGaN/GaN DBR structure is introduced in examples 1 to 3, and the emergent light at one side of the substrate is reflected to the upper surface of a sample, so that the light extraction efficiency of the device is improved; it was confirmed that the high light extraction efficiency of the light emitting devices prepared in examples 1 to 3 was improved by about 50% compared to the light emitting device prepared in the comparative example. In addition, the hole injection layer in the embodiments 1 to 3 is p-type InGaN, and compared with p-GaN in the comparative example, the p-type InGaN has a narrower forbidden band width, reduces the acceptor activation energy of Mg, improves the hole concentration of a p-type material, and further improves the hole injection efficiency of a p-n junction, so as to achieve the purpose of improving the light emitting efficiency of a device; it was confirmed that the hole concentration of p-GaN in the comparative example was 10¹⁸cm^-3The hole concentration of the p-type InGaN material in examples 1-3 can reach 10¹⁹cm^-3。

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.