CN100483752C - Gallium nitride series light-emitting diode with high luminous efficiency and manufacturing method thereof - Google Patents

Abstract

The invention relates to a gallium nitride series light-emitting diode with high luminous efficiency and a manufacturing method thereof, which discloses a manufacturing process and a structure for generating a surface grain structure of a P-type semiconductor layer, wherein the grain structure can interrupt a light guide effect and reduce the generation probability of hexahedral pit defects.

Description

GaN series light-emitting diode with high luminous efficiency and manufacturing method thereof

technical field

The invention relates to gallium nitride series light-emitting diodes, in particular to a gallium nitride series light-emitting diode with high luminous efficiency and a manufacturing method thereof.

technical background

The conventional light-emitting diode device using a sapphire substrate to grow GaN series is shown in FIG. 1 , which is called a traditional structure. It includes a gallium nitride buffer layer 2, an N-type gallium nitride ohmic contact layer 3, a light-emitting layer 4 including indium gallium nitride, a P-type aluminum gallium nitride coating layer 5 and a P-type The gallium nitride ohmic contact layer 6 is epitaxially grown on the sapphire substrate 1, and finally a P-type semi-penetrating metal conductive layer 7 is formed on the P-type gallium nitride ohmic contact layer 6, and a P-type metal electrode 8 is formed. On the semi-penetrating metal conductive layer 7 and an N-type metal electrode 9 on the N-type GaN ohmic contact layer 3 . Due to the distribution of the refractive index (n=2.4) of the multilayer GaN epitaxial structure, the refractive index (n=1.77) of the sapphire substrate and the refractive index (n=1.5) of the resin capping material used for packaging, the light emitting layer Only nearly 25% of the emitted light can be emitted at one time without being reflected by the interface, while the remaining 75% of the light is confined by the light guide structure composed of the sapphire substrate and the resin capping material for packaging and is reflected through multiple interfaces However, the probability of light being reabsorbed is increased so that it cannot be effectively extracted and utilized. Therefore, the light extraction mechanism of this LED device structure is limited by the absorption of the semi-penetrating metal conductive layer and the reabsorption of the internal epitaxial structure.

In order to improve the light extraction efficiency of the light-emitting diode device structure, for example, U.S. Patent No. 6,091,085 has disclosed a method for interrupting the light-guiding effect. One method is to first produce roughened lines on the surface of the sapphire substrate, and then grow nitrogen on it. GaN series light-emitting diode multi-layer epitaxial structure, another method is to directly grow the GaN series light-emitting diode multi-layer epitaxial structure on the sapphire substrate, and then directly create a tunnel from the surface of the epitaxial structure, the tunnel to Extending in the direction of the sapphire substrate and implanting a material with a refractive index lower than that of the multilayer GaN epitaxial structure (n=2.4).

However, because method one needs to use mechanical polishing or chemical etching to make its rough texture, it is easy to cause uneven surface roughness on the sapphire substrate, which affects the conditions of subsequent epitaxy and is not easy to control its production yield; and method two is for Making tunnels and implanting materials requires increasing the complexity of making and correspondingly increasing its cost.

Furthermore, U.S. Patent No. 6,495,862 discloses a structure of a gallium nitride series light-emitting diode device with a convex surface to reduce the light emitted by the light-emitting layer from being reflected by the interface between the semi-penetrating metal layer and the resin cover for packaging. It increases its external quantum efficiency, but in order to make such surface cylindrical or semicircular embossed lines, it also needs to increase the complexity of its production and relatively increase its cost.

In addition, U.S. Patent No. 6,531,719 discloses a method for interrupting the photoconductive effect and reducing the bending deformation of the epitaxial chip caused by stress. The method is to use the conditions of epitaxial growth to grow an inner layer of aluminum nitride with a woven stripe structure , the inner layer of aluminum nitride with a weave-like stripe structure is interposed between the light-emitting layer and the sapphire substrate to interrupt the photoconductive effect to increase its external quantum efficiency, and this structure can be further formed on the inner layer of aluminum nitride A metal reflective layer is used to reflect light emitted from the light-emitting layer to the direction of the sapphire substrate to increase its external quantum efficiency. This patent discloses that when MOCVD is used to grow the aluminum nitride inner layer, ammonia gas (NH3) and trimethylaluminum (TMA) are introduced into the reaction chamber and the flow rate of ammonia gas is controlled to control the shape of the weave stripes , and then grow other multilayer epitaxial structures, according to the paper (APL 71, (9), sep.1 (1997), p.1204) reveals that this method is easy to cause hexagonal shaped pits (Hexagonal shaped pits), if such The pits are very easy to extend from the inner layer of aluminum nitride through the light-emitting layer to the surface P-type ohmic contact layer, causing the metal atoms to diffuse into the light-emitting layer through the pits when the subsequent semi-penetrating metal layer or metal electrode is fabricated. Destroy the element characteristics of light-emitting diodes and shorten the working life of the elements.

According to the teaching of the paper J.L.RouViere et al (Journal of Nitride-Semiconductor-Research, Vol.1, (1996) Art.33), when using MOCVD epitaxy technology to grow GaN thin films on sapphire substrates, according to different epitaxial growth conditions , The appearance of the surface can be roughly divided into three types: hexagonal cone rough surface, flat surface, and granular rough surface. Experiments have proved that the appearance of the surface is determined by the polarization direction of the surface atomic layer and the migration rate of the surface atoms. When the surface growth mechanism is mainly controlled by the nitrogen atom polarization (N-polarity), the surface state is Rough surface, when the surface growth mechanism is mainly controlled by gallium atom polarization (Ga-polarity), its surface state is a flat surface, and when the surface of the gallium nitride film is a flat surface, it represents hexagonal shaped pits ) is reduced or even eliminated.

Therefore, how to propose a novel gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method for the above-mentioned problems can not only improve the traditional shortcomings of requiring additional processing (such as: mechanical polishing or chemical etching) to interrupt the photoconductive effect For a long time, it has been the ardent expectation of users and the goal pursued by the inventor, and the inventor has been engaged in the research, development, and sales of light-emitting diode related products for many years. Based on practical experience in sales, it is thought and improved ideas, which are impoverished by the individual. After many researches and designs and special discussions, finally a gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method improvement can solve the above-mentioned problems.

Contents of the invention

The main purpose of the present invention is to provide a gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method. By growing a P-type cladding layer epitaxially and forming a P-type transition layer on the cladding layer, Control the strain of these two layers, and then form a P-type ohmic contact layer on the P-type transition layer, so that the surface of the P-type semiconductor layer has a textured structure, through which the light-guiding effect can be interrupted to increase its external quantum efficiency.

The secondary purpose of the present invention is to provide a gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method. its working life.

A gallium nitride series light-emitting diode with high luminous efficiency, its main structure includes:

a substrate, the substrate is located at the bottom of the light emitting diode element;

A semiconductor layer, the semiconductor layer is connected to the upper part of the substrate, has an N-type semiconductor layer, a light-emitting layer and a P-type semiconductor layer, wherein the light-emitting layer is interposed between the N-type semiconductor layer and the P-type semiconductor layer between;

Wherein, the surface of the P-type semiconductor layer has lines produced in an epitaxial process.

The textures on the surface of the P-type semiconductor layer can interrupt the photoconductive effect.

The surface texture of the P-type semiconductor layer is formed by controlling the strain in the P-type semiconductor epitaxial layer.

The P-type semiconductor layer may further include a P-type cladding layer and a P-type transition layer on the P-type cladding layer, and a P-type ohmic contact layer is formed on the P-type transition layer.

Said gallium nitride series light emitting diode with high luminous efficiency may further include a reflective layer under the light emitting layer.

The substrate is selected from one of sapphire, silicon carbide, zinc oxide, zirconium diboride, gallium arsenide, or silicon.

The N-type semiconductor layer can be NB _x Al _y In _z Ga _1-xyz NpAs _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q ≦1 and x+y+z=1 and p+q=1), or NB _x Al _y n _z Ga _1-xyz N _p P _q layer (0≦x≦1, 0≦y≦1, 0≦ z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1).

The P-type semiconductor layer can be a PB _x Al _y In _z Ga _1-xyz N _p As _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0 ≦q≦1 and x+y+z=1, p+q=1), or PB _x Al _y In _z Ga _1-xyz N _p P _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1).

The light-emitting layer can be a B _x Al _y In _z Ga _1-xyz N _p As _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q ≦1 and x+y+z=1, p+q=1) or B _x Al _y In _z Ga _1-xyz N _p P _q layer (0≦x≦1, 0≦y≦1, 0≦z≦ 1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1) a single quantum well structure, or a combination of these two layers.

The P-type cladding layer is a cladding layer that changes the extension strain.

The P-type transition layer can be a superlattice structure composed of a semiconductor layer.

The P-type ohmic contact layer can be a superlattice structure composed of a semiconductor layer.

The P-type cladding layer contains magnesium atomic concentration between 5×10 ¹⁹ and 5×10 ²⁰ cm ⁻³ .

The P-type transition layer contains magnesium atoms with a concentration between 5×10 ¹⁷ and 5×10 ¹⁹ cm ⁻³ .

The concentration of magnesium atoms contained in the P-type ohmic contact layer is between the P-type cladding layer and the P-type transition layer.

The superlattice structure can be formed by stacking semiconductor layers with different compositions, different thicknesses and different impurity doping concentrations.

The reflective layer may be a Distributed Bragg Reflector formed by stacking semiconductor layers alternately.

A method for manufacturing a gallium nitride series light-emitting diode with high luminous efficiency, the main steps of which include:

providing a substrate; and

Forming a semiconductor layer on the substrate to form a light-emitting element, wherein the semiconductor layer at least includes a light-emitting layer, a P-type semiconductor layer and an N-type semiconductor layer, and the light-emitting layer is between the N-type semiconductor layer and the P-type semiconductor between layers;

Wherein the main steps of forming the P-type semiconductor layer include:

forming a P-type cladding layer on the light-emitting layer, wherein the cladding layer can increase the amount of strain between each layer;

forming a p-type transition layer on the p-type cladding layer; and

A P-type ohmic contact layer is formed on the P-type transition layer.

The P-type cladding layer is doped with magnesium atoms to increase the amount of strain between each layer.

The formation method of the P-type cladding layer is to dope magnesium atoms to increase the amount of strain between each layer, then interrupt the growth of the epitaxial layer and control the interruption time to change the strain amount of the epitaxial layer.

The method for forming the P-type cladding layer is to dope magnesium atoms to increase the strain between the epitaxial layers, then interrupt the growth of the epitaxial layers and use temperature changes to change the strain of the epitaxial layers.

The method for forming the p-type cladding layer is to dope magnesium atoms to increase the amount of strain between each layer, and then interrupt the growth of the epitaxial layer and form several gallium atoms, indium atoms, etc. on the surface of the p-type cladding layer. Or a single atomic layer (Monolayer) of aluminum atoms to change the strain of the epitaxial layer.

The method for forming the p-type cladding layer is to increase the composition of aluminum in the p-type cladding layer to increase the strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and control the interruption time to change the strain of the epitaxial layer.

The method for forming the p-type cladding layer is to increase the composition of aluminum in the p-type cladding layer to increase the strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and change the strain of the epitaxial layer by changing the temperature.

The method for forming the p-type cladding layer is to increase the composition of aluminum in the p-type cladding layer to increase the amount of strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and form several layers on the surface of the p-type cladding layer. Monolayers of gallium atoms, indium atoms or aluminum atoms can be used to change the strain of the epitaxial layer.

The method for forming the P-type transition layer is to control the composition of aluminum or the doping amount of magnesium atoms in the epitaxial layer to reduce the amount of strain between the P-type cladding layer.

The method for forming the P-type transition layer is to reduce the strain between the epitaxial layer and the P-type cladding layer, then interrupt the growth of the epitaxial layer and control the interruption time to change the strain of the epitaxial layer.

The method for forming the P-type transition layer is to reduce the strain between the epitaxial layer and the P-type cladding layer, then interrupt the growth of the epitaxial layer and use temperature changes to change the strain of the epitaxial layer.

The formation method of the P-type transition layer is to reduce the amount of strain between the epitaxial layer and the P-type cladding layer, then interrupt the growth of the epitaxial layer and form several gallium atoms, indium atoms or aluminum atoms on the surface of the p-type transition layer Atom monolayer (Monolayer) to change the amount of strain of the epitaxial layer.

The said interruption time is between 1 second and 2 minutes.

The temperature change is between 5°C and 300°C.

The number of monoatomic layers is between 1 and 5.

The method for forming the P-type ohmic contact layer is to increase the flow rate of dicyclopentadiene magnesium (Cp ₂ Mg) or reduce the temperature to increase the doping concentration of magnesium atoms during epitaxial growth.

In order to achieve the purpose of the invention, the invention provides a gallium nitride series light-emitting diode with high luminous efficiency and a manufacturing method thereof. What the present invention discloses is a method and its structure for producing a P-type semiconductor layer with a surface texture structure. Through the formation of the texture structure, the photoconductive effect can be interrupted and the generation of hexahedral pits can be reduced. The method disclosed in the invention is to form a P-type transition layer on the cladding layer during epitaxial growth of the P-type cladding layer, control the strain of the two layers, and then form a P-type ohmic contact layer on the P-type cladding layer. On the P-type transition layer, through this method and structure, the P-type semiconductor layer can have a surface texture structure, so as to increase the external quantum efficiency and increase its working life.

Description of drawings

Fig. 1 is the schematic diagram of the light-emitting diode of prior art;

Fig. 2 is the manufacturing flowchart of the light-emitting diode of a preferred embodiment of the present invention;

Fig. 3 is the schematic diagram of the LED of a preferred embodiment of the present invention;

4A to 4E are SEM images of the texture of the P-type semiconductor layer according to a preferred embodiment of the present invention.

Description of figure number

1 Sapphire substrate

2 GaN buffer layer

3 N-type gallium nitride ohmic buffer layer

4 Light-emitting layer of InGaN

5 P-type aluminum gallium nitride cladding layer

6 P-type gallium nitride ohmic contact layer

7 P-type transparent metal conductive layer

8 Positive electrode pad

9 Negative electrode pad

10 Substrate

20 semiconductor layer

22 N-type semiconductor layer

24 luminous layer

26 P-type semiconductor layer

260 P type cladding layer

262 P-type transition layer

264 P-type ohmic contact layer

Detailed ways

The present invention provides a gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method, which discloses the process and structure of the surface texture structure of a P-type semiconductor layer, through which the photoconductive effect can be interrupted And reduce the generation probability of hexahedral pit defects, and the method disclosed by the present invention is to control the application of extension (tension) and compression (compression) when generating a P-type cladding layer and a P-type transition layer Variable, and then form a P-type ohmic contact layer on the P-type transition layer, through the control method and structure of this epitaxial growth process, the surface of the P-type semiconductor layer can have a textured structure, so as to increase the external quantum efficiency and increase its working life.

In order to enable the examiner to have a further understanding and understanding of the structural features and the achieved effects of the present invention, a preferred embodiment and a detailed description are provided, as follows:

The purpose of the present invention is to provide a method and its structure for interrupting the photoconductive effect, which can solve the problem that the post-process must be applied in the prior art, such as: mechanical polishing or chemical etching, to generate lines, and its production yield is not easy Control, or use MOCVD epitaxy technology to generate stripes, but it is easy to cause hexahedral pits, resulting in shortened device life; the process and structure disclosed in the present invention do not require post-processing, and will not produce The hexagonal pothole is actually an innovative technology.

First, please refer to Fig. 2, which is a manufacturing flow chart of a light-emitting diode in a preferred embodiment of the present invention; The main steps include:

Step S11, providing a substrate;

Step S12, forming an N-type semiconductor layer on the substrate;

Step S13, forming a light-emitting layer on the N-type semiconductor layer;

Step S14, forming a P-type cladding layer on the light-emitting layer, wherein the cladding layer has the function of increasing the amount of strain between each layer;

Step S15, forming a P-type transition layer on the P-type cladding layer; and

Step S16, forming a P-type ohmic contact layer on the P-type transition layer.

Wherein, in step S14 to step S16, the method of increasing the amount of strain of the cladding layer and forming the P-type semiconductor layer with texture includes the following methods:

1. Doping high-concentration magnesium atoms in the P-type cladding layer to increase the amount of strain between the epitaxial layers, then interrupting the growth of the epitaxial layer and controlling the interruption time to change the strain amount of the epitaxial layer, wherein the interruption time is between Between 1 second and 2 minutes, a P-type transition layer doped with a low concentration of magnesium atoms is subsequently grown, and finally an ohmic contact layer with a moderate concentration of magnesium atoms is grown.

2. Doping a high concentration of magnesium atoms in the P-type cladding layer to increase the amount of strain between the epitaxial layers, then interrupting the growth of the epitaxial layer and using temperature changes to change the amount of strain of the epitaxial layers, wherein the temperature change is between Between 5°C and 300°C, a P-type transition layer doped with a low concentration of magnesium atoms is subsequently grown, and finally an ohmic contact layer with a moderate concentration of magnesium atoms is grown.

3. Doping high-concentration magnesium atoms in the P-type cladding layer to increase the strain between the epitaxial layers, then interrupting the growth of the epitaxial layer and forming several gallium atoms, indium atoms or A single atomic layer (Monolayer) of aluminum atoms is used to change the strain of the epitaxial layer, wherein the single atomic layer is between 1 and 5, followed by the growth of a P-type transition layer doped with low concentration of magnesium atoms, and finally another growth layer An ohmic contact layer with a moderate doping concentration of magnesium atoms.

4. Increase the composition of aluminum in the P-type cladding layer to increase the amount of strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and control the interruption time to change the amount of strain in the epitaxial layer, wherein the interruption time is between 1 second and 2 seconds Within minutes, a P-type transition layer doped with a low concentration of magnesium atoms is subsequently grown, and finally an ohmic contact layer with a moderate concentration of magnesium atoms is grown.

5. Increase the composition of aluminum in the P-type AlGaN cladding layer to increase the amount of strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and use the temperature change to change the amount of strain of the epitaxial layer, wherein the temperature change is between Between 5°C and 300°C, a P-type transition layer doped with a low concentration of magnesium atoms is subsequently grown, and finally an ohmic contact layer with a moderate concentration of magnesium atoms is grown.

6. Increase the composition of aluminum in the P-type cladding layer to increase the amount of strain between the epitaxial layers, then interrupt the growth of the epitaxial layer and form several gallium atoms, indium atoms or aluminum atoms on the surface of the P-type cladding layer. Atomic layer (Monolayer) to change the strain of the epitaxial layer, wherein the monoatomic layer is between 1 and 5, followed by growing a magnesium atom-doped low-concentration P-type transition layer, and finally growing a magnesium atom-doped Moderately concentrated ohmic contact layer.

Also, the method for forming the P-type transition layer is as follows:

1. Control the composition of aluminum in the epitaxial layer or the doping amount of magnesium atoms to reduce the amount of strain between the P-type cladding layer.

2. Reduce the amount of strain between the epitaxial layer and the P-type cladding layer, then interrupt the growth of the epitaxial layer and control the interruption time to change the strain amount of the epitaxial layer, wherein the interruption time is between 1 second and 2 minutes.

3. Reduce the strain between the epitaxial layer and the P-type cladding layer, then stop the growth of the epitaxial layer and change the strain of the epitaxial layer by changing the temperature, wherein the temperature change is between 5°C and 300°C.

4. Reduce the amount of strain between the epitaxial layer and the P-type cladding layer, then interrupt the growth of the epitaxial layer and form several monolayers of gallium atoms, indium atoms or aluminum atoms on the surface of the p-type transition layer, The single atomic layer is between 1 and 5, so as to change the strain amount of the epitaxial layer.

The method for forming the P-type ohmic contact layer is to increase the flow rate of dicyclopentadiene magnesium (Cp ₂ Mg) or reduce the temperature to increase the doping concentration of magnesium atoms during epitaxial growth.

Furthermore, please refer to FIG. 3 , which is a schematic diagram of a light-emitting diode of a preferred embodiment of the present invention; as shown in the figure, the present invention discloses a gallium nitride series light-emitting diode with high luminous efficiency, and its main structure is It includes: a substrate 10, which is located at the bottom of the light emitting diode element; a semiconductor layer 20, which is connected to the upper part of the substrate 10, and has an N-type semiconductor layer 22, a light-emitting layer 24 and a P-type semiconductor layer 26, wherein the light-emitting layer 24 is between the N-type semiconductor layer 22 and the P-type semiconductor layer 26; wherein the P-type semiconductor layer 26 includes a P-type cladding layer 260, a P-type transition layer 262 and a P-type ohmic contact layer 264 are grown sequentially on the light-emitting layer 24, and the P-type cladding layer 260 is a cladding layer that increases the amount of strain; and may further include a reflective layer on the light-emitting layer Under 24, the structure is a distributed Bragg Reflector (Distributed Bragg Reflector) that is stacked alternately with semiconductor layers.

The substrate 10 is selected from one of sapphire, silicon carbide, zinc oxide, zirconium diboride, gallium arsenide, or silicon; and the N-type semiconductor layer 22 can be NB _{x Aly} In _z Ga _{1- xyz} N _p As _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1 ), or NB _x Al _y In _z Ga _1-xyz N _p P _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1); the P-type semiconductor layer 26 can be a PB _x Al _y In _z Ga _1-xyz N _p As _q layer (0≦x≦1, 0≦y≦1 , 0≦z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1, p+q=1), or PB _x Al _y In _z Ga _1-xyz N _p P _q Layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q≦1 and x+y+z=1 and p+q=1); the light-emitting layer 24 can be B _x Al _y In _z Ga _1-xyz N _p As _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦p≦1, 0≦q≦1 and x +y+z=1, p+q=1) or B _X Al _y In _z Ga _1-xyz N _p P _q layer (0≦x≦1, 0≦y≦1, 0≦z≦1, 0≦ p≦1, 0≦q≦1 and x+y+z=1 and p+q=1) a single quantum well structure, or a combination of these two layers.

Wherein, the P-type cladding layer is a cladding layer that changes the extension strain.

In addition, the P-type transition layer 262 and the P-type ohmic contact layer 264 are a superlattice structure composed of semiconductor layers, and the superlattice structure can be alternately composed of semiconductor layers with different compositions, different thicknesses, and different impurity doping concentrations. stacked.

The P-type semiconductor layer 26 has a texture, which can interrupt the photoconductive effect; and the P-type cladding layer contains magnesium atoms 5×10 ¹⁹ ~5×10 ²⁰ cm ^-3 , and the P-type transition layer contains magnesium atoms 5 ×10 ¹⁷ ~5×10 ¹⁹ cm ^-3 , the content of magnesium atoms contained in the P-type ohmic contact layer is between the P-type cladding layer and the P-type transition layer; wherein, the P-type semiconducting layer The lines are shown in Figure 4A to Figure 4E, which is the

An SEM image of the texture of the P-type semiconductor layer in a preferred embodiment of the invention; as shown in the figure, the texture is produced in an epitaxial process, not a post-processing process as in the conventional technology, so transparent Through the method of the present invention, the texture can be produced together in the epitaxial process to achieve the purpose of interrupting the light guiding effect.

The gallium nitride series light-emitting diode with high luminous efficiency and its manufacturing method provided by the present invention are to form a P-type semiconductor layer with a surface texture structure by controlling the strain of the epitaxial layer during the epitaxial growth process, so as to achieve the interrupted Efficacy of light guiding effect.

The invention does not require post-processing, and directly controls the generation of textures in the manufacturing process, and generates textures on the P-type semiconductor layer as a function of light scattering to interrupt the light-guiding effect formed by the substrate and the resin capping material used for packaging, so as to increase Its external quantum efficiency can reduce the probability of hexahedral pits in the light-emitting diode structure and increase the working life of its components.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. For example, all equivalent changes and modifications are made in accordance with the shape, structure, characteristics and spirit described in the scope of the claims of the present invention. , should be included in the scope of the claims of the present invention.

Claims (29)

1, a kind of gallium nitride of high-luminous-efficiency series light-emitting diode, its primary structure comprises:

One substrate is positioned at the bottom of this light-emitting diode;

Semi-conductor layer is connected to this substrate top, has a n type semiconductor layer, a luminescent layer and a p type semiconductor layer, and wherein, luminescent layer is between this n type semiconductor layer and this p type semiconductor layer;

It is characterized in that: described P type semiconductor laminar surface has the lines that is produced in an epitaxial manufacture process, and the surface pattern that this p type semiconductor layer had is to be formed by the dependent variable in the control P type semiconductor epitaxial loayer.

2, the gallium nitride of high-luminous-efficiency as claimed in claim 1 series light-emitting diode, it is characterized in that: the lines that the P type semiconductor laminar surface is had can interrupt photoconductive effect.

3, the gallium nitride of high-luminous-efficiency as claimed in claim 1 series light-emitting diode is characterized in that: this p type semiconductor layer can further comprise a P type coating layer and a P type transition zone on this P type coating layer and form a P type ohmic contact layer on this P type transition zone.

4, the gallium nitride of high-luminous-efficiency as claimed in claim 1 series light-emitting diode is characterized in that: can further comprise a reflector under this luminescent layer.

5, the gallium nitride of high-luminous-efficiency as claimed in claim 1 series light-emitting diode is characterized in that: described substrate is to be selected from one of them of sapphire, carborundum, zinc oxide, zirconium diboride, GaAs or silicon materials.

6, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode is characterized in that: described P type coating layer is that the coating layer of dependent variable (tension strain) is extended in a change.

7, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode, it is characterized in that: described P type transition zone can be the superlattice structure that semi-conductor layer is formed.

8, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode, it is characterized in that: described P type ohmic contact layer can be the superlattice structure that semi-conductor layer is formed.

9, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode, it is characterized in that: described P type coating layer comprises magnesium atom concentration between 5 * 10 ¹⁹～5 * 10 ²⁰Cm ^-3Between.

10, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode, it is characterized in that: described P type transition zone comprises magnesium atom concentration between 5 * 10 ¹⁷～5 * 10 ¹⁹Cm ^-3Between.

11, the gallium nitride of high-luminous-efficiency as claimed in claim 3 series light-emitting diode, it is characterized in that: it is between this P type coating layer and this P type transition zone that described P type ohmic contact layer comprises magnesium atom concentration.

12, as the gallium nitride of claim 7 or 8 described high-luminous-efficiencies series light-emitting diode, it is characterized in that: described superlattice structure can be made up of difference, the semiconductor layer of different-thickness and different impurities doping content piles up alternately and forms.

13, the gallium nitride of high-luminous-efficiency as claimed in claim 4 series light-emitting diode, it is characterized in that: described reflector can be for being piled up the distributed Bragg reflector (Distributed Bragg Reflector) that forms alternately by semiconductor layer.

14, a kind of gallium nitride of high-luminous-efficiency series manufacturing method for LED, its key step is to include:

One substrate is provided; And

Form semi-conductor layer and form a light-emitting component on this substrate, wherein this semiconductor layer comprises a luminescent layer, a p type semiconductor layer and a n type semiconductor layer at least, and this luminescent layer is between this n type semiconductor layer and this p type semiconductor layer;

It is characterized in that the key step that described p type semiconductor layer forms is to include:

Form a P type coating layer on this luminescent layer, wherein this coating layer can increase and each layer between dependent variable;

Form a P type transition zone on this P type coating layer; And

Form a P type ohmic contact layer on this P type transition zone.

15, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED is characterized in that: described P type coating layer is that magnesium-doped atom is with the dependent variable between raising and each layer.

16, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer be magnesium-doped atom with increase with each layer between dependent variable, then interrupt the growth of epitaxial loayer and control break period dependent variable with the change epitaxial loayer.

17, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer is magnesium-doped atom to increase the dependent variable between the epitaxial loayer, then interrupts the growth of epitaxial loayer and utilizes variations in temperature to change the dependent variable of epitaxial loayer.

18, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer is that magnesium-doped atom is with the dependent variable between increase and each layer, then interrupt the growth of epitaxial loayer and form several gallium atoms in the surface of p type coating layer, the monoatomic layer (Monolayer) of phosphide atom or aluminium atom is to change the dependent variable of epitaxial loayer.

19, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer is to increase the composition of aluminium in the p type coating layer to increase the dependent variable between the epitaxial loayer, then interrupts the epitaxial loayer growth and controls break period to change the dependent variable of epitaxial loayer.

20, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer is to increase the composition of aluminium in the p type coating layer to increase the dependent variable between the epitaxial loayer, then interrupts the growth of epitaxial loayer and utilizes variations in temperature to change the dependent variable of epitaxial loayer.

21, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type coating layer is to increase the composition of aluminium in the p type coating layer to increase the dependent variable between the epitaxial loayer, then interrupt the growth of epitaxial loayer and form several gallium atoms in the surface of p type coating layer, the monoatomic layer (Monolayer) of phosphide atom or aluminium atom is to change the dependent variable of epitaxial loayer.

22, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED is characterized in that: the formation method of described P type transition zone be the composition of aluminium in the control epitaxial loayer or magnesium atom doping with reduce and P type coating layer between dependent variable.

23, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type transition zone is the dependent variable that reduces between epitaxial loayer and the P type coating layer, then interrupts the growth of epitaxial loayer and controls break period to change the dependent variable of epitaxial loayer.

24, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type transition zone is the dependent variable that reduces between epitaxial loayer and the P type coating layer, then interrupts the growth of epitaxial loayer and utilizes variations in temperature to change the dependent variable of epitaxial loayer.

25, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED, it is characterized in that: the formation method of described P type transition zone is the dependent variable that reduces between epitaxial loayer and the P type coating layer, then interrupt the growth of epitaxial loayer and form several gallium atoms in the surface of p type transition zone, the monoatomic layer (Monolayer) of phosphide atom or aluminium atom is to change the dependent variable of epitaxial loayer.

26, as the gallium nitride series manufacturing method for LED of claim 16 or 19 or 23 described high-luminous-efficiencies, it is characterized in that: described break period is between 1 second to 2 minutes.

27, as the gallium nitride series manufacturing method for LED of claim 17 or 20 or 24 described high-luminous-efficiencies, it is characterized in that: described variations in temperature is between 5 ℃ to 300 ℃.

28, as the gallium nitride series manufacturing method for LED of claim 18 or 21 or 25 described high-luminous-efficiencies, it is characterized in that: described monoatomic layer is between 1 to 5.

29, the gallium nitride of high-luminous-efficiency as claimed in claim 14 series manufacturing method for LED is characterized in that: the formation method of described P type ohmic contact layer is to increase dicyclopentadiene magnesium (Cp when utilizing epitaxial growth ₂Mg) flow or reduction temperature are to increase the doping content of magnesium atom.

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