CN117317098A - Light emitting diode and light emitting device - Google Patents

Abstract

The present application provides a light-emitting diode and a light-emitting device. The epitaxial structure of the light-emitting diode includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer sequentially stacked from the front surface of the substrate. The first electrode is located above the N-type layer and The N-type layer is conductively connected; wherein there is a first reflective structure between the N-type semiconductor layer and the first electrode, and the first reflective structure includes at least a group of sequentially stacked first material layers and a second The material layer, the first material layer and the second material layer are AlGaInP material layers with different Al component contents. The above-mentioned first reflective structure can reflect the light that is emitted vertically or at a small angle from the active layer and is blocked by the first electrode and cannot be emitted, and reflects this part of the light back to the active layer. The active layer absorbs and re-emits the light. Emitting light is repeated for multiple rounds, and the light emission angle of a part of the light after re-emitting changes, so as to avoid being emitted from the first electrode, thereby improving the external quantum efficiency of the light-emitting diode.

Description

A kind of light-emitting diode and light-emitting device

Technical field

The present invention relates to the technical field of semiconductor devices and devices, and in particular to a light-emitting diode and a light-emitting device.

Background technique

Conventional GaAs red light flip-chip structure (RS) core chips usually form electrode extension strips in order to improve the current expansion performance. However, during packaging, the electrode extension strips are prone to being crushed. In order to solve this problem, the electrode extension strip is generally eliminated through structural optimization design to reduce the crushing of the electrode extension strip during the packaging process.

However, after the electrode extension strip is eliminated, the current expandability becomes worse and the current is concentrated in a small area below the electrode. This causes most of the light emitted by the active layer to be concentrated directly below the electrode. Due to the obstruction of the electrode, this part of the light cannot be emission, therefore, causing problems with the lower external quantum efficiency of LEDs.

Contents of the invention

In view of the above-mentioned defects in the GaAs red light flip-chip structure in the prior art, the present invention provides a light-emitting diode and a light-emitting device to solve one or more of the above problems.

One embodiment of the present application provides a light-emitting diode, which at least includes:

A substrate, said substrate having a substrate front side and a substrate back side arranged oppositely;

An epitaxial structure is formed on the front side of the substrate, the epitaxial structure includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer sequentially stacked from the front side of the substrate;

A first electrode located above the N-type layer and electrically connected to the N-type layer;

There is a first reflective structure between the N-type semiconductor layer and the first electrode. The first reflective structure includes at least one group of reflective film groups, and each group of reflective module groups includes sequentially stacked first material layers. and a second material layer, where the first material layer and the second material layer are AlGaInP material layers with different Al component contents.

Another embodiment of the present application provides a light-emitting device, which includes: a circuit substrate and at least one light-emitting diode fixed to the circuit substrate, where the light-emitting diode includes the light-emitting diode provided by the present application.

As mentioned above, the light-emitting diode and light-emitting device of the present application have the following beneficial effects:

The light-emitting diode of the present application includes a substrate, an epitaxial structure formed on the front side of the substrate, and a first electrode. The epitaxial structure includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer sequentially stacked from the front side of the substrate. , the first electrode is located above the N-type layer and is conductively connected to the N-type layer; wherein there is a first reflective structure between the N-type semiconductor layer and the first electrode, and the first reflective structure includes at least one set of reflective Each group of reflective modules includes a first material layer and a second material layer stacked in sequence, and the first material layer and the second material layer are AlGaInP material layers with different Al component contents. The above-mentioned first reflective structure can reflect the light that is emitted vertically or at a small angle from the active layer and is blocked by the first electrode and cannot be emitted, and reflects this part of the light back to the active layer. The active layer absorbs it and re-emits it. Lighting is repeated for multiple rounds, and the light emission angle of a part of the light after re-illumination changes, thereby avoiding the first electrode and being emitted, thereby improving the external quantum efficiency of the light-emitting diode.

Description of drawings

Figure 1 shows a schematic structural diagram of a light-emitting diode in the prior art.

FIG. 2 shows a schematic structural diagram of a light-emitting diode provided in Embodiment 1 of the present application.

FIG. 3 is a flow chart of the manufacturing method of the light emitting diode shown in FIG. 2 .

Figure 4 shows a schematic diagram of forming an epitaxial structure on a growth substrate.

FIG. 5 shows a schematic diagram of forming a dielectric layer and a second reflective structure above the structure shown in FIG. 4 .

Figure 6 shows a schematic structural diagram of forming a bonding layer over a substrate.

FIG. 7 shows a schematic structural diagram of bonding the structure shown in FIG. 5 to a substrate.

Figure 8 shows a schematic diagram of the structure after removing the growth substrate.

FIG. 9 shows a schematic top structural view of the light-emitting diode shown in Embodiment 1.

FIG. 10 shows a schematic top structural view of a light-emitting diode provided for an optional embodiment of Embodiment 1.

FIG. 11 shows a schematic structural diagram of a light-emitting device provided in Embodiment 2 of the present invention.

Component label description

01. Substrate; 02. Active layer; 03. N-type semiconductor layer; 04. First electrode; 05. P-type semiconductor layer; 06. Second electrode; 100. Substrate; 101. Epitaxial structure; 1011. N type semiconductor layer; 1012, active layer; 1013, P-type semiconductor; 102, first electrode; 1021, extension strip; 103, first reflective structure; 104, bonding layer; 105, second reflective structure; 106; medium Layer, 1060, through hole; 107, back gold layer; 108, insulating protective layer; 200, growth substrate; 201, buffer layer; 202, first cutoff layer; 203, N-type ohmic contact layer; 204, second cutoff layer; 300, light-emitting device; 301, circuit substrate; 302, light-emitting diode.

Detailed ways

The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

As shown in Figure 1, in the prior art, a conventional GaAs red light flip-chip structure includes a substrate and a P-type semiconductor layer 05, an active layer 02 and an N-type semiconductor layer 03 formed above the substrate 01. The N-type semiconductor layer A first electrode 04 and a second electrode 06 are formed on one side and the P-type semiconductor layer side respectively. One side of the N-type semiconductor layer 03 serves as the light-emitting surface, and the first electrode 04 only covers part of the surface of the N-type semiconductor layer 03 . In addition, in order to reduce the crushing phenomenon of the electrode extension strips during the packaging process, the current extension strips above the N-type semiconductor layer 03 are usually eliminated. However, at this time, when voltage is applied to the first electrode 04 and the second electrode 06, the current is concentrated. Directly below the first electrode 04, when the light radiated by the active layer 02 emerges, small-angle light or vertically emitted light will be blocked by the first electrode 04 as shown in Figure 1 and cannot emit, thus affecting the light emitting effect and brightness of the chip. The loss is greater.

In order to solve the above-mentioned problems of light-emitting diodes in the prior art, this application provides a light-emitting diode, which at least includes:

A substrate, said substrate having a substrate front side and a substrate back side arranged oppositely;

An epitaxial structure is formed on the front side of the substrate, the epitaxial structure includes a P-type semiconductor layer, an active layer, and an N-type semiconductor layer sequentially stacked from the front side of the substrate;

A first electrode located above the N-type layer and electrically connected to the N-type layer;

There is a first reflective structure between the N-type semiconductor layer and the first electrode. The first reflective structure includes at least one group of reflective film groups, and each group of reflective module groups includes sequentially stacked first material layers. and a second material layer, where the first material layer and the second material layer are AlGaInP material layers with different Al component contents. As mentioned above, in this application, there is a first reflective structure between the N-type semiconductor layer and the first electrode. The first reflective structure includes at least one group of reflective film groups, and each group of reflective module groups includes sequentially stacked first material layers. and a second material layer, where the first material layer and the second material layer are AlGaInP material layers with different Al component contents. The first reflective structure can reflect the light that is emitted vertically or at a small angle from the active layer and is blocked by the first electrode and cannot be emitted, and reflects this part of the light back to the active layer. The active layer absorbs and emits light again. , repeated for multiple rounds, the light emission angle of part of the light after re-illumination changes, thereby avoiding the first electrode and being emitted, thus improving the external quantum efficiency of the light-emitting diode.

Optionally, the first reflective structure includes 2 to 50 groups of the reflective film groups. The number of groups of reflective modules can be set according to actual needs, thereby achieving optimal reflection effects and improving the light extraction efficiency of the light-emitting diodes.

Optionally, the content of the Al component in the first material layer ranges from 35% to 50%.

Optionally, the content of the Al component in the second material layer ranges from 25% to 40%.

The addition of Al in the first material layer and the second material layer and the selection of the Al composition make the first material layer and the second material layer have different reflectivities of light, thereby achieving a total reflection effect. Moreover, the above material selection can reduce the absorption of light by the N-type layer under the first reflective structure, further improving the light extraction effect of the light-emitting diode.

Optionally, the optical thickness of both the first material layer and the second material layer is nλ/4, where λ is the wavelength of the light radiated by the active layer. The optical thickness of the material is set according to the wavelength radiated by the light-emitting diode to better reflect the light radiated by the active layer and achieve the optimal reflection effect.

Optionally, the wavelength λ of the light radiated by the active layer ranges from 550 nm to 950 nm. The light of this wavelength is red light,

Optionally, the first material layer is an (Al _0.4 Ga _0.6 ) _0.5 In _0.5 P layer, and the second material layer is an (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P layer. The above-mentioned specific material combination of the first material layer and the second material layer can achieve its optimal reflection effect and improve the light extraction efficiency of the light-emitting diode.

Optionally, the thickness of the first material layer ranges from 10 nm to 20 nm, and the thickness of the second material layer ranges from 20 nm to 30 nm. The above-mentioned thickness setting of the first material layer and the second material layer enables the optimal reflection effect to be achieved without affecting the overall thickness of the device and the diffusion of current.

Optionally, the light-emitting diode further includes:

A bonding layer, located between the substrate and the epitaxial structure, used to bond the epitaxial structure and the substrate;

A second reflective structure is located between the bonding layer and the epitaxial structure to form a metal mirror structure;

A dielectric layer is located between the second reflective structure and the epitaxial structure. A through hole is formed in the dielectric layer. The second reflective structure fills the through hole and is in contact with the P-type semiconductor layer of the epitaxial structure. connect.

Both the above-mentioned bonding layer and the second reflective structure can be formed as a metal layer, and the metal layer can further reflect the light emitted to this part, which is beneficial to further improving the light extraction effect of the light-emitting diode.

Optionally, in the stacking direction of the epitaxial structure, the first reflective structure is located directly below the first electrode, and the projected area of the first electrode on the front surface of the substrate is less than or equal to The projected area of the first reflective structure on the front surface of the substrate. The above arrangement of the first reflective structure enables it to mainly reflect the part of light blocked by the electrode so that it can be emitted in the area outside the electrode without affecting the emission of light in other areas.

Optionally, the N-type semiconductor layer at least includes an N-type waveguide layer, an N-type confinement layer, an N-type window layer, a second cutoff layer and an N-type ohmic contact layer sequentially stacked from the active layer, and A first reflective structure is formed between the N-type window layer and the second stop layer, and the first electrode is formed over the N-type ohmic contact. Since the second cutoff layer GaInP layer has a certain absorption effect on light, disposing the first reflective structure 103 below it is beneficial to reducing its absorption of light and improving the light extraction efficiency of the light-emitting diode.

Optionally, the light-emitting diode further includes a second electrode located on the back side of the substrate, and the second electrode forms an electrical connection with the P-type semiconductor layer. The above-mentioned back gold layer can be used as a second electrode, or form a second electrode separately. The above-mentioned back gold layer can also play a reflective role, further reflecting light emitted through the substrate.

Another embodiment of the present invention provides a light-emitting device, which includes: a circuit substrate and at least one light-emitting diode fixed to the circuit substrate, where the light-emitting diode includes the light-emitting diode provided by the present application.

Embodiment 1

This embodiment provides a light-emitting diode. As shown in Figure 2, the light-emitting diode at least includes a substrate 100, an epitaxial structure 101 formed above the substrate 100, a first electrode 102 formed above the epitaxial structure 101, and a first electrode 102 formed above the epitaxial structure 101. Reflective structures 103. The epitaxial structure 101 at least includes a P-type semiconductor layer 1013, an active layer 1012, and an N-type semiconductor layer 1011 sequentially stacked above the substrate 100. The first electrode 102 is formed above the N-type semiconductor layer 1011 and is electrically connected to the N-type semiconductor layer 1011 . The first reflective structure 103 is formed between the first electrode 102 and the N-type semiconductor layer 1011. In an optional embodiment, the epitaxial structure 101 is an AlGaInP epitaxial structure, and one side of the N-type semiconductor layer 1011 is the light-emitting side. The N-type semiconductor layer 1011 is optionally an N-type AlInP or AlGaInP layer, used to provide electrons. The N-type AlInP or AlGaInP layer is doped with n-type impurities to provide electrons. The n-type impurities can be, for example, Si, Ge, Sn, Se, and Te. The P-type semiconductor layer 1013 is optionally a P-type AlInP or AlGaInP layer, and holes are provided by doping P-type impurities. The P-type impurities can be Mg, Zn, Ca, Sr, C, Ba, etc. In this embodiment, the P-type impurity is preferably Mg or C.

Referring also to FIG. 2 , the first reflective layer 103 is essentially a part of the epitaxial structure 101 , and is formed during the process of forming the epitaxial structure 101 . The first reflective structure 103 is located between the N-type semiconductor layer 1011 and the first electrode 102. Alternatively, it may be a DBR structure formed by alternately stacking layers of different materials. In this embodiment, the above-mentioned first reflective structure 103 includes at least one set of reflective modules. Each reflective module group includes a first material layer and a second material layer stacked at one time, wherein the above-mentioned first material layer and second material layer They are AlGaInP material layers with different Al component contents. In an optional embodiment, the first reflective structure 103 includes 2 to 50 groups of the reflective film groups, for example, 7 groups, 15 groups, 20 groups, 30 groups, or 40 groups, 50 groups, etc. The content of the Al component in the first material layer ranges from 35% to 50%, for example, 35%, 40%, 45%, 50%; the content of the Al component in the second material layer ranges from 25% to 40%, For example, 25%, 30%, 35%, 40%. Further, the content of the Al component in the first material layer is between 40%, and the content of the Al component in the second material layer is between 30%, that is, at this time, the first material layer is (Al _0.4 Ga _0.6 ) _0.5 In _0.5 P layer, the second material layer is (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P layer. The above material layer combination can achieve optimal radiation effect.

In addition, the optical thickness and actual thickness of each material layer in the reflective module are important parameters for achieving the optimal reflective effect. In this embodiment, the optical thickness of the first material layer and the second material layer are both nλ/4 , where λ is the wavelength of light radiated by the active layer 1012 in the above-mentioned epitaxial structure 101. For example, in this embodiment, the wavelength λ of the light radiated by the active layer 1012 is between 550 nm and 950 nm. The optical thickness of the above-mentioned first material layer and the second material layer is determined according to the actual wavelength or wavelength range of the active layer 1012 radiation. Then, the actual thickness of the first material layer and the second material layer is confirmed based on the relationship between the optical thickness and the refractive index of the material layer, and the above-mentioned reflective module is formed based on the actual thickness. In this embodiment, the thickness of the first material layer is between 10 nm and 20 nm, and the thickness of the second material layer is between 20 nm and 30 nm. Further, the thickness of the first material layer may be, for example, 15 nm, and the thickness of the second material layer may be 25 nm.

Referring also to FIG. 2 , in this embodiment, the above-mentioned reflective layer is formed within the orthographic projection range of the first electrode 102 on the plane where the N-type semiconductor layer 1011 is located, or is formed outside the above-mentioned orthographic projection range of the first electrode 102 . within a smaller area. That is, the orthogonal projected area of the first electrode 102 on the plane where the N-type semiconductor layer 1011 is located is equal to or slightly smaller than the orthogonal projected area of the first reflective structure 103 on the plane where the N-type semiconductor layer 1011 is located. This ensures that the first reflective structure 103 can completely reflect the light blocked by the first electrode 102, thereby increasing its emission effect, thereby increasing the light extraction effect of the light emitting diode.

In an optional embodiment, the above-mentioned N-type semiconductor layer 1011 usually includes an N-type waveguide layer stacked in order from near to far from the active layer 1012, which layer is usually an N-type AlGaInP layer, and an N-type confinement layer, which is usually an N-type Type AlInP layer, and N-type window layer, which is usually an AlGaInP layer. As shown in Figure 2, the N-type layer as the light-emitting surface is formed into a roughened surface, which is conducive to further improving the light extraction rate and improving the light-emitting effect. The roughened surface is formed on the above-mentioned N-type window layer.

Optionally, a second cutoff layer 204 and an N-type ohmic contact layer 203 are also formed between the first reflective structure 103 and the first electrode 102 , where the second cutoff layer 204 can be a GaInP layer and the N-type ohmic contact layer 203 Can be a GaAs layer. The first electrode 102 is in contact with the N-type ohmic contact layer 203 to reduce the contact resistance with the first semiconductor layer and improve the electrical performance of the light-emitting diode. The first reflective structure 103 is located between the N-type semiconductor layer 1011 (specifically, the N-type window layer) and the second cutoff layer 204. Since the second cutoff layer GaInP layer has a certain absorption effect on light, the first reflective structure 103 is The structure 103 is arranged below it, which is beneficial to reducing its absorption of light and improving the light extraction efficiency.

Also shown in Figure 2, the light-emitting diode of this embodiment also includes: a bonding layer 104, located between the substrate 100 and the epitaxial structure 101, for bonding the epitaxial structure 101 and the substrate 100; a second reflective structure 105, Located between the bonding layer 104 and the epitaxial structure 101, a metal mirror structure is formed; the dielectric layer 106 is located between the second reflective structure 105 and the epitaxial structure 101. A through hole 1060 is formed in the dielectric layer 106 and filled with the second reflective structure 105. The via hole 1060 is electrically connected to the P-type semiconductor layer 1013 of the epitaxial structure 101 . The above-mentioned dielectric layer 106 can be one or any combination of SiO ₂ , SiN, SiON, TiO _{2 ,} etc. The dielectric layer 106 and the second reflective structure 105 can form a total reflection structure to further improve the reflection of light. In an optional embodiment, a back gold layer 107 may also be formed on the side of the substrate 100 opposite to the side where the epitaxial structure 101 is bonded, and the back gold layer 107 may serve as a second electrode to communicate with the P-type semiconductor layer 1013 It is electrically connected and can also play a certain reflection role to reflect the light emitted through the substrate 100 to improve the light emitting effect of the light-emitting diode. In addition, an insulating protective layer 108 can also be provided on the surface of the light-emitting diode to protect the device from external impurities and water vapor and improve its service life.

As shown in FIG. 9 , it shows a schematic top view of the light emitting diode shown in FIG. 2 . As can be seen from FIG. 9 , the first electrode 102 of the light-emitting diode does not form an extension strip or similar structure. This can avoid the problem of crushing the extension strip when packaging the light-emitting diode, and accordingly the reliability of the light-emitting diode can be improved.

Of course, it can be understood that, as shown in FIG. 10 , expansion strips 1021 can also be formed around the first electrode 102 , in which case the lateral expansion of the current can be further improved and the light extraction effect can be improved.

This embodiment also passes the manufacturing method of the above-mentioned light-emitting diode. As shown in Figure 3, the manufacturing method includes the following steps:

S100: Provide a growth substrate;

S200: Sequentially grow N-type, active layer, and second semiconductor layer structures on the growth substrate to form an epitaxial structure;

Referring to FIG. 4 , a growth substrate 200 is first provided. The growth substrate 200 can be any substrate suitable for epitaxy, such as Si substrate, SiC substrate, sapphire substrate, GaAs substrate, etc. In this embodiment, a GaAs substrate is used.

Epitaxial growth is performed on the front side of the GaAs substrate. Before growing the N-type semiconductor layer 1011, first, the buffer layer 201, the first stop layer 202, the N-type ohmic contact layer 203 and the second stop layer 204 are grown on the front side of the growth substrate 200. The buffer layer 201 may be a GaAs layer. The buffer layer 201 can effectively alleviate lattice defects caused by lattice mismatch between the growth substrate 200 and the N-type semiconductor layer 1011 and improve the quality of subsequent crystal growth. The first stop layer 202 may be formed as a GaInP layer. The first stop layer 202 serves as an etching stop layer when the growth substrate 200 is subsequently removed to control the etching depth and prevent unnecessary damage or performance loss caused by over-etching or under-etching. The N-type ohmic contact layer 203 is formed as a GaAs layer. When the growth substrate 200 is removed, the N-type ohmic contact layer 203 is exposed to form ohmic contact with the subsequently formed first electrode 102 to reduce contact resistance. The second stop layer 204 is formed as a GaInP layer and serves as a stop layer for subsequent roughening of the N-type semiconductor layer 1011 to prevent excessive roughening.

Then, the first reflective structure 103 is formed above the second cutoff layer 204. As mentioned above, in this embodiment, the first reflective structure 103 is formed as a DBR structure in which layers of different materials are alternately stacked. For example, it includes alternately stacked first material layers and second material layers. In this embodiment, in order to achieve its reflection effect without affecting its impact on the epitaxial structure 101, the first material layer is selected to be (Al _0.4 Ga _0.6 ) _0.5 In _0.5 P layer, and the second material layer is (Al _0.3 Ga _0.7 ) _0.5 In _0.5 P layer. The above-mentioned first material layer and second material layer are alternately deposited above the second cutoff layer 204. Optionally, 2 to 50 groups of first material layers and second material layers are deposited until a DBR structure with a required thickness is formed.

After forming the first reflective structure 103, the above-mentioned N-type semiconductor layer 1011 is formed. Specifically, an N-type window layer, an N-type confinement layer and an N-type waveguide layer are sequentially deposited on the first semiconductor layer, where the N-type window layer is AlGaInP. The thickness of the N-type window layer is usually about 3 μm. The N-type window layer is subsequently roughened to form a roughened surface as the light-emitting surface. The N-type confinement layer is an N-type AlInP layer, and the N-type waveguide layer is an N-type AlGaInP layer. The above structure can be deposited and formed by common means and will not be described in detail here.

After the N-type semiconductor layer 1011 is formed, a multiple quantum well layer is deposited on its surface to form an active layer 1012. The active layer 1012 may be a multiple quantum well layer formed of AlGaInP/AlInP. A P-type semiconductor layer 1013 is formed above the active layer 1012. Specifically, a P-type AlGaInP layer is sequentially deposited as a P-type waveguide layer and a P-type AlInP layer is used as a P-type confinement layer. A transition layer and a current expansion layer may also be deposited above the P-type confinement layer, and the current expansion layer may be a GaP layer.

S300: Form a second reflective structure;

Referring to FIG. 5 , after the above-mentioned P-type semiconductor layer 1013 is formed, a step of forming a second reflective structure 105 above the P-type semiconductor layer 1013 is also included. The second reflective structure 105 can be a metal specular reflection layer or a metal specular reflection layer and a metal specular reflection layer. The dielectric layer 106 forms a total reflection structure. In this embodiment, a total reflection structure is optional. For example, first, a dielectric layer 106 is deposited above the P-type semiconductor layer 1013. The dielectric layer 106 may be one of SiO ₂ , SiN, SiON, TiO _{2 ,} etc., or a combination of any of them. The dielectric layer 106 is then etched to form a through hole 1060 penetrating the dielectric layer 106 , and then a metal layer is deposited above the dielectric layer 106 and in the through hole 1060 to form a metal reflective layer. The metal reflective layer may be a metal material such as Ag, Au, Al, or an alloy layer of two or more metal materials.

S400: Bond the epitaxial layer to the substrate on one side of the P-type semiconductor layer;

Referring to FIG. 6 , a substrate 100 is first provided. The substrate 100 may be an insulating substrate, a semiconductor substrate, a conductive substrate, etc. In this embodiment, a semiconductor Si substrate is taken as an example. A bonding layer 104 is then formed on the front side of the substrate 100 . Then, as shown in FIG. 7 , one side of the P-type semiconductor layer 1013 is bonded to the substrate 100 through the bonding layer 104 .

S500: Remove the growth substrate;

Then, as shown in FIG. 8 , the growth substrate 200 is removed, for example, by a wet etching method to peel off the growth substrate 200 to expose the ohmic contact layer.

Referring again to FIG. 2 , a first electrode 102 is formed on the surface of the exposed ohmic contact layer. Optionally, the first electrode 102 is a metal layer such as Ti, Pt, Au, or an alloy layer. In addition, a back gold layer 107 is formed on the back side of the substrate 100 at the same time. The back gold layer 107 can also play a reflective role to reflect the light emitted from the substrate 100 to further improve the light extraction effect of the light emitting diode; in addition, the back gold layer 107 can also play a reflective role. The gold layer 107 can also be used as a second electrode to be electrically connected to the P-type semiconductor layer 1013 . After that, the ohmic contact layer and the second stop layer 204 covered by the first electrode 102 are etched away until the first reflective structure 103 is exposed, and then roughening is performed from the surface of the first reflective structure 103. Due to the thickness of the first reflective structure 103 Thin, therefore, a roughened surface is usually formed on the surface of the N-type semiconductor layer 1011, and this roughened surface is the light-emitting surface of the light-emitting diode.

Finally, it also includes forming an insulating protective layer 108 on the surface area and side walls of the exposed light-emitting diode to protect the device from damage by external water vapor, magazines, etc., and extend its service life. The insulating protective layer 108 may be one or more composite material layers selected from SiO ₂ , SiN, and SiON.

Embodiment 2

This embodiment provides a light-emitting device. As shown in Figure 11, the light-emitting device 300 includes a circuit substrate 301 and at least one light-emitting diode 302 fixed to the circuit substrate 301. The light-emitting diode includes the light-emitting diode provided in the first embodiment of the present application. led. Because the light-emitting device includes the light-emitting diode provided in Embodiment 1, it has good light emitting effect and has better reliability.

The above embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed in the present invention shall still be covered by the claims of the present invention.

Claims (13)

1. A light emitting diode comprising at least:

the substrate is provided with a substrate front surface and a substrate back surface which are oppositely arranged;

the epitaxial structure is formed on one side of the front surface of the substrate and comprises a P-type semiconductor layer, an active layer and an N-type semiconductor layer which are sequentially stacked from the front surface of the substrate;

the first electrode is positioned above the N-type layer and is in conductive connection with the N-type layer;

the first reflecting structure comprises at least one group of reflecting film groups, each group of reflecting film groups comprises a first material layer and a second material layer which are sequentially overlapped, and the first material layer and the second material layer are AlGaInP material layers with different Al component contents.

2. The led of claim 1, wherein the first reflective structure comprises 2 to 50 groups of the reflective film groups.

3. The led of claim 1, wherein the Al component in the first material layer is present in an amount of 35% to 50%.

4. The led of claim 1, wherein the Al component in the second material layer is present in an amount of 25% to 40%.

5. The light emitting diode of claim 1, wherein the first material layer and the second material layer each have an optical thickness of nλ/4, where λ is a wavelength of light radiated by the active layer.

6. The led of claim 5, wherein the wavelength λ of the light emitted by the active layer is between 550nm and 950nm.

7. A light emitting diode according to any one of claims 1 to 3, wherein the first material layer is (Al _0.4 Ga _0.6 ) _0.5 In _0.5 A P layer of a second material of (Al _0.3 Ga _0.7 ) _0.5 In _0.5 And a P layer.

8. A light emitting diode according to any one of claims 1 to 3 wherein the first material layer has a thickness of 10nm to 20nm and the second material layer has a thickness of 20nm to 30nm.

9. A light emitting diode according to claim 1 further comprising:

the bonding layer is positioned between the substrate and the epitaxial structure and is used for bonding the epitaxial structure and the substrate;

the second reflecting structure is positioned between the bonding layer and the epitaxial structure to form a metal mirror structure;

the dielectric layer is positioned between the second reflecting structure and the epitaxial structure, a through hole is formed in the dielectric layer, and the second reflecting structure fills the through hole and is electrically connected with the P-type semiconductor layer of the epitaxial structure.

10. The light-emitting diode according to claim 1, wherein the first reflective structure is located directly below the first electrode in a stacking direction of the epitaxial structure, and a projected area of the first electrode on the substrate front surface is smaller than or equal to a projected area of the first reflective structure on the substrate front surface.

11. The light emitting diode of claim 1, wherein the N-type semiconductor layer comprises at least an N-type waveguide layer, an N-type confinement layer, an N-type window layer, and a second stop layer and an N-type ohmic contact layer stacked in order from the active layer, the first reflective structure is formed between the N-type window layer and the second stop layer, and the first electrode is formed over the N-type ohmic contact.

12. The led of claim 1, further comprising a second electrode on the back side of the substrate, the second electrode forming an electrical connection with the P-type semiconductor layer.

13. A light emitting device, comprising: a circuit substrate and at least one light emitting diode fixed to the circuit substrate, the light emitting diode comprising the light emitting diode of any one of claims 1 to 12.