An epitaxial structure of a light emitting diode

Abstract

The application provides an epitaxial structure of a light emitting diode, and relates to the technical field of semiconductor devices. The epitaxial structure comprises a substrate, a first etching transition layer, an etching stop layer, a second etching transition layer and a light emitting epitaxial layer which are sequentially stacked, the lattice mismatch degree between the first etching transition layer and the substrate is less than the lattice mismatch degree between the etching stop layer and the substrate, and the lattice mismatch degree between the second etching transition layer and the light emitting epitaxial layer is less than the lattice mismatch degree between the etching stop layer and the light emitting epitaxial layer. The first etching transition layer with a small lattice mismatch degree with the substrate and the second etching transition layer with a small lattice mismatch degree with the light emitting epitaxial layer are respectively inserted on both sides of the etching stop layer, so that the lattice matching degree between the etching composite layer and the substrate and the light emitting epitaxial layer is high, the crystal growth quality of the light emitting epitaxial layer is improved, the white edge problem of the surface of the light emitting epitaxial layer is improved, and the performance and yield of the light emitting diode prepared subsequently are improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor device technology, and more specifically, to an epitaxial structure of a light-emitting diode. Background Technology

[0002] Infrared light-emitting diodes (LEDs) are widely used in communication, remote sensing devices, and other fields due to their low power consumption, miniaturization, and high reliability. With rapid industrial development, the demand for high-power infrared LEDs is constantly increasing, driving the research and development and production of high-power infrared LEDs. Currently, infrared LEDs are mainly fabricated using phosphide and arsenide material systems grown via vapor phase epitaxy. Ordinary upright infrared LEDs suffer from low light extraction efficiency, resulting in a technical bottleneck in power output. With the rapid development of industry, the demand for high-power infrared LEDs is increasing, making the manufacture of high-power infrared LEDs a development trend. Using metal-organic chemical vapor deposition (MOCVD) to epitaxially grow flip-chip infrared LEDs with multi-quantum-well structures can achieve high light extraction efficiency. However, the use of epitaxial layer stripping technology results in a different corrosion cutoff layer compared to other epitaxial material systems, and poor material interfaces can lead to poor crystal growth quality in the active region, easily causing white edges on the epitaxial layer surface. This affects further performance improvement of the subsequently fabricated infrared LEDs and reduces the fabrication yield. Therefore, improving the interface between the corrosion-blocking layer and the luminescent material, as well as addressing crystal quality issues, has become an important research direction for enhancing the performance of infrared light-emitting diodes. Utility Model Content

[0003] In view of this, this application provides an epitaxial structure for a light-emitting diode, which effectively solves the technical problems existing in the prior art, ensures a high degree of lattice matching between the etched composite layer and the substrate and the light-emitting epitaxial layer, thereby improving the crystal growth quality of the light-emitting epitaxial layer, improving the white edge problem on the surface of the light-emitting epitaxial layer, and improving the performance and yield of the subsequently fabricated light-emitting diode.

[0004] To achieve the above objectives, the technical solution provided in this application is as follows:

[0005] An epitaxial structure for a light-emitting diode includes:

[0006] Substrate;

[0007] An etch composite layer is located on the growth surface of the substrate. The etch composite layer includes a first etch transition layer, an etch stop layer, and a second etch transition layer. The etch stop layer is located on the side of the first etch transition layer away from the substrate, and the second etch transition layer is located on the side of the etch stop layer away from the substrate.

[0008] The light-emitting epitaxial layer is located on the side of the etched composite layer away from the substrate, wherein the lattice mismatch between the first etch transition layer and the substrate is less than the lattice mismatch between the etch stop layer and the substrate; and the lattice mismatch between the second etch transition layer and the light-emitting epitaxial layer is less than the lattice mismatch between the etch stop layer and the light-emitting epitaxial layer.

[0009] Optionally, the epitaxial structure of the light-emitting diode further includes:

[0010] A buffer layer is located between the substrate and the etch composite layer, wherein the lattice mismatch between the first etch transition layer and the buffer layer is less than the lattice mismatch between the etch stop layer and the buffer layer.

[0011] Optionally, the buffer layer is a GaAs buffer layer.

[0012] Optionally, the lattice mismatch between the first corrosion transition layer and the buffer layer is less than 0.01%.

[0013] Optionally, the first etch transition layer is an AlGaInAsP layer;

[0014] The etching stop layer includes at least one sub-stop layer stacked along the direction from the substrate to the etching composite layer, and each sub-stop layer is one of AlGaInP layer, GaInP layer, and AlInP layer.

[0015] The second etch transition layer includes at least one sub-transition layer stacked along the direction from the substrate to the etch composite layer, each of the sub-transition layers being an AlGaInAsP layer or an AlGaInP layer, and the sub-transition layer in contact with the light-emitting epitaxial layer being an AlGaInAsP layer.

[0016] Optionally, the thickness of both the first corrosion transition layer and the second corrosion transition layer is less than the thickness of the corrosion stop layer.

[0017] Optionally, the light-emitting epitaxial layer includes a first type of semiconductor confinement layer, an active layer, and a second type of semiconductor confinement layer, wherein the active layer is located on the side of the first type of semiconductor confinement layer opposite to the substrate, and the second type of semiconductor confinement layer is located on the side of the active layer opposite to the substrate.

[0018] Optionally, the light-emitting epitaxial layer further includes:

[0019] An at least one of the following is disposed between the etched composite layer and the first type of semiconductor confinement layer, and sequentially stacked along the direction from the substrate to the etched composite layer: an ohmic contact layer, a current transport layer, a roughening layer, and a first type of semiconductor current spreading layer.

[0020] Optionally, the lattice mismatch between the second corrosion transition layer and the ohmic contact layer is less than the lattice mismatch between the corrosion stop layer and the ohmic contact layer.

[0021] Optionally, a second type of semiconductor current spreading layer is located on the side of the second type of semiconductor confinement layer opposite to the substrate.

[0022] Compared with existing technologies, the technical solution provided in this application has at least the following advantages:

[0023] This application provides an epitaxial structure for a light-emitting diode (LED). The LED epitaxial structure includes: a substrate; an etch composite layer located on the growth surface of the substrate, the etch composite layer including a first etch transition layer, an etch stop layer, and a second etch transition layer, the etch stop layer being located on the side of the first etch transition layer facing away from the substrate, and the second etch transition layer being located on the side of the etch stop layer facing away from the substrate; and a light-emitting epitaxial layer located on the side of the etch composite layer facing away from the substrate, wherein the lattice mismatch between the first etch transition layer and the substrate is less than the lattice mismatch between the etch stop layer and the substrate; and the lattice mismatch between the second etch transition layer and the light-emitting epitaxial layer is less than the lattice mismatch between the etch stop layer and the light-emitting epitaxial layer.

[0024] As can be seen from the above, the epitaxial structure of the light-emitting diode provided in this application inserts a first etch transition layer with a small lattice mismatch with the substrate and a second etch transition layer with a small lattice mismatch with the light-emitting epitaxial layer on both sides of the etch stop layer. This results in a high lattice matching degree between the etch composite layer and the substrate and the light-emitting epitaxial layer, thereby improving the crystal growth quality of the light-emitting epitaxial layer, improving the white edge problem on the surface of the light-emitting epitaxial layer, and improving the performance and yield of the subsequently fabricated light-emitting diode. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0026] Figure 1 A stacked diagram of the epitaxial structure of a light-emitting diode provided in an embodiment of this application;

[0027] Figure 2 A stacked diagram of another epitaxial structure of a light-emitting diode provided in an embodiment of this application;

[0028] Figure 3 A stacked diagram of another epitaxial structure of a light-emitting diode provided in an embodiment of this application;

[0029] Figure 4 A stacked diagram of another epitaxial structure of a light-emitting diode provided in an embodiment of this application;

[0030] Figure 5 A flowchart illustrating a method for fabricating an epitaxial structure of a light-emitting diode, as provided in this application embodiment;

[0031] Figure 6 A flowchart illustrating another method for fabricating an epitaxial structure of a light-emitting diode provided in this application embodiment;

[0032] Figure 7 A flowchart illustrating another method for fabricating an epitaxial structure of a light-emitting diode provided in this application embodiment.

[0033] Figure label:

[0034] 100 - Substrate; 200 - Etching composite layer; 210 - First etch transition layer; 220 - Second etch transition layer; 230 - Etching stop layer; 300 - Light-emitting epitaxial layer; 310 - Type I semiconductor confinement layer; 320 - Type II semiconductor confinement layer; 330 - Active layer; 340 - Ohmic contact layer; 350 - Current transport layer; 360 - Roughening layer; 370 - Type I semiconductor current spreading layer; 380 - Type II semiconductor current spreading layer; 400 - Buffer layer. Detailed Implementation

[0035] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] As described in the background section, infrared light-emitting diodes (LEDs) are widely used in communication, remote sensing devices, and other fields due to their low power consumption, miniaturization, and high reliability. With rapid industrial development, the demand for high-power infrared LEDs is constantly increasing, driving the research and development and production of high-power infrared LEDs. Currently, infrared LEDs are mainly fabricated using phosphide and arsenide material systems grown via vapor phase epitaxy. Ordinary upright infrared LEDs suffer from low light extraction efficiency, resulting in a technical bottleneck in power output. With the rapid development of industry, the demand for high-power infrared LEDs is increasing, making the manufacture of high-power infrared LEDs a development trend. Using metal-organic chemical vapor deposition (MOCVD) to epitaxially grow flip-chip infrared LEDs with multi-quantum-well structures can achieve high light extraction efficiency. However, the use of epitaxial layer stripping technology results in a different corrosion cutoff layer compared to other epitaxial material systems, and the poor material interface can lead to poor crystal growth quality in the active region. This can easily cause white edges (i.e., white defects on the surface of the epitaxial layer), thus affecting further performance improvement of the subsequently fabricated infrared LEDs and reducing the fabrication yield. Therefore, improving the interface between the corrosion-blocking layer and the luminescent material, as well as addressing crystal quality issues, has become an important research direction for enhancing the performance of infrared light-emitting diodes.

[0037] Based on this, embodiments of this application provide an epitaxial structure for a light-emitting diode and a method for fabricating the same, effectively solving the technical problems existing in the prior art. This ensures high lattice matching between the etched composite layer, the substrate, and the light-emitting epitaxial layer, thereby improving the crystal growth quality of the light-emitting epitaxial layer, mitigating the white edge problem on the surface of the light-emitting epitaxial layer, and improving the performance and yield of the subsequently fabricated light-emitting diode. Optionally, the epitaxial structure of the light-emitting diode provided in this application can be an epitaxial structure for an infrared light-emitting diode.

[0038] To achieve the above objectives, the technical solutions provided in this application are as follows, in specific combination with... Figures 1 to 7 The technical solutions provided in the embodiments of this application will be described in detail.

[0039] refer to Figure 1The diagram shown is a stacked configuration of an epitaxial structure of a light-emitting diode (LED) according to an embodiment of this application. The epitaxial structure of the LED provided in this embodiment includes: a substrate 100; an etch composite layer 200 located on the growth surface of the substrate 100; the etch composite layer 200 includes a first etch transition layer 210, an etch stop layer 230, and a second etch transition layer 220; the etch stop layer 230 is located on the side of the first etch transition layer 210 facing away from the substrate 100, and the second etch transition layer 220 is located on the side of the etch stop layer 230 facing away from the substrate 100. The light-emitting epitaxial layer 300 located on the side of the etched composite layer 200 away from the substrate 100 has the following characteristics: the lattice mismatch between the first etch transition layer 210 and the substrate 100 is less than the lattice mismatch between the etch stop layer 230 and the substrate 100; and the lattice mismatch between the second etch transition layer 220 and the light-emitting epitaxial layer 300 is less than the lattice mismatch between the etch stop layer 230 and the light-emitting epitaxial layer 300. That is, the light-emitting epitaxial layer 300 is composed of multiple stacked layers, and in the stacked layer that contacts the second etch transition layer 220, its lattice mismatch with the second etch transition layer 220 is less than its lattice mismatch with the etch stop layer 230.

[0040] Understandably, in the epitaxial structure of the light-emitting diode provided in this application embodiment, a first etching transition layer 210 with a small lattice mismatch with the substrate 100 and a second etching transition layer 220 with a small lattice mismatch with the light-emitting epitaxial layer 300 are respectively inserted on both sides of the etching stop layer 230. This results in a high lattice matching degree between the etching composite layer 200, the substrate 100, and the light-emitting epitaxial layer 300, thereby improving the crystal growth quality of the light-emitting epitaxial layer 300, improving the white edge problem on the surface of the light-emitting epitaxial layer 300, and improving the performance and yield of the subsequently fabricated light-emitting diode. Optionally, the thickness of the first etching transition layer 210 and the second etching transition layer 220 provided in this application embodiment are both smaller than the thickness of the etching stop layer 230. A thicker etching stop layer 230 can better block etching, while a thinner etching transition layer can ensure higher growth quality and improve the lattice matching degree between the etching composite layer 200, the substrate 100, and the light-emitting epitaxial layer 300. The thickness of the first corrosion transition layer 210 can be greater than, less than or equal to the thickness of the second corrosion transition layer 220, and this needs to be specifically designed according to the actual application.

[0041] refer to Figure 2The diagram shows a stacked configuration of another epitaxial structure of a light-emitting diode provided in this embodiment. The light-emitting epitaxial layer 300 provided in this embodiment includes a first type semiconductor confinement layer 310, an active layer 330, and a second type semiconductor confinement layer 320. The active layer 330 can be a multi-quantum-well active layer. The active layer 330 is located on the side of the first type semiconductor confinement layer 310 facing away from the substrate 100, and the second type semiconductor confinement layer 320 is located on the side of the active layer 330 facing away from the substrate 100. Optionally, the first type semiconductor provided in this embodiment can be an N-type semiconductor, and the second type semiconductor can be a P-type semiconductor; or, the first type semiconductor provided in this embodiment can be a P-type semiconductor, and the second type semiconductor can be an N-type semiconductor.

[0042] In some embodiments, the epitaxial structure of the light-emitting diode can be further optimized by a stacked layer. For example, the epitaxial structure of the light-emitting diode provided in this embodiment can also include a buffer layer 400 disposed between the substrate 100 and the etched composite layer 200. (See reference...) Figure 3 The diagram shows a stacked configuration of another epitaxial structure of a light-emitting diode (LED) provided in this application embodiment. The LED epitaxial structure further includes a buffer layer 400 located between the substrate 100 and the etched composite layer 200. The lattice mismatch between the first etch transition layer 210 and the buffer layer 400 is less than the lattice mismatch between the etch stop layer 230 and the buffer layer 400. The buffer layer 400 further improves the lattice fit between the etched composite layer 200 and the substrate 100, and absorbs the thermal stress caused by the difference in thermal expansion coefficients during the fabrication of the LED epitaxial structure. This improves the cracking or warping of the subsequently grown LED epitaxial layer 300, suppresses the extension of surface defects on the substrate 100, and improves the crystal growth quality. Optionally, the lattice mismatch between the first etch transition layer 210 and the buffer layer 400 provided in this application embodiment is less than 0.01%.

[0043] In some embodiments, the stacked layers of the light-emitting epitaxial layer 300 can be optimized to improve the performance of the subsequently fabricated light-emitting diode. (Reference) Figure 4The diagram shows a stacked configuration of another light-emitting diode (LED) epitaxial structure provided in this application embodiment. The LED epitaxial layer provided in this application embodiment further includes at least one of the following: an ohmic contact layer 340, a current transport layer 350, a roughening layer 360, and a first-type semiconductor current extension layer 370, sequentially stacked between the etched composite layer 200 and the first-type semiconductor confinement layer 310, along the direction from the substrate 100 towards the etched composite layer 200; and / or a second-type semiconductor current extension layer 380 located on the side of the second-type semiconductor confinement layer 320 facing away from the substrate 100. The ohmic contact layer 340 provides a low-resistance contact, reducing the contact resistance between the electrodes and semiconductor of the subsequently fabricated LED. The current transport layer 350 laterally extends the current, reducing current congestion and avoiding localized overheating. The roughening layer 360 disrupts total internal reflection conditions through surface roughening, improving light extraction efficiency. The first-type semiconductor current extension layer 370 and the second-type semiconductor current extension layer 380 achieve uniform current distribution, reducing localized heating and efficiency loss.

[0044] In other words, the light-emitting epitaxial layer 300 provided in this application embodiment may include only one of the following: ohmic contact layer 340, current transport layer 350, roughening layer 360, first type semiconductor current spreading layer 370, and second type semiconductor current spreading layer 380. Alternatively, the light-emitting epitaxial layer 300 provided in this application embodiment may include a combination of at least two of the following: ohmic contact layer 340, current transport layer 350, roughening layer 360, first type semiconductor current spreading layer 370, and second type semiconductor current spreading layer 380. This application does not impose specific limitations on this. When the light-emitting epitaxial layer 300 includes a combination of at least two of the following: an ohmic contact layer 340, a current transport layer 350, a roughening layer 360, and a first-type semiconductor current spreading layer 370, the combined layer is stacked in a manner in which the ohmic contact layer 340, the current transport layer 350, the roughening layer 360, and the first-type semiconductor current spreading layer 370 are stacked sequentially along the direction from the substrate 100 toward the etched composite layer 200. For example, when the light-emitting epitaxial layer 300 includes a combination of an ohmic contact layer 340 and a roughening layer 360, the roughening layer 360 is located on the side of the ohmic contact layer 340 away from the substrate 100; when the light-emitting epitaxial layer 300 includes a combination of an ohmic contact layer 340, a current transport layer 350, and a first-type semiconductor current spreading layer 370, the current transport layer 350 is located on the side of the ohmic contact layer 340 away from the substrate 100, and the first-type semiconductor current spreading layer 370 is located on the side of the current transport layer 350 away from the substrate 100, and so on. When the ohmic contact layer 340 contacts the second corrosion transition layer 220, the lattice mismatch between the second corrosion transition layer 220 and the ohmic contact layer 340 is less than the lattice mismatch between the corrosion stop layer 230 and the ohmic contact layer 340.

[0045] In some embodiments, the epitaxial structure of the light-emitting diode provided in this application can be the epitaxial structure of an infrared light-emitting diode, wherein the substrate 100 can be a GaAs substrate, the buffer layer 400 can be a GaAs buffer layer, the ohmic contact layer 340 can be a GaAs ohmic contact layer, the current transport layer 350 can be an AlGaInP current transport layer, the roughening layer 360 can be an AlGaInP roughening layer, the first type semiconductor current spreading layer 370 can be an AlGaInP current spreading layer, the first type semiconductor confinement layer 310 can be an AlInP confinement layer, the second type semiconductor confinement layer 320 can be an AlInP confinement layer, and the second type semiconductor current spreading layer 380 can be an AlGaInP current spreading layer. Furthermore, the first etching transition layer 210 provided in this application can be made of AlGaInAsP. The etching stop layer 230 provided in this application can include at least one sub-stop layer stacked along the direction from the substrate 100 to the etching composite layer 200, and the sub-stop layer is made of AlGaInP, GaInP, or AlInP. Furthermore, the second etch transition layer 220 provided in this application embodiment includes at least one sub-transition layer superimposed along the direction from the substrate 100 to the etch composite layer 200. The material of the sub-transition layer is AlGaInAsP or AlGaInP, and the material of the sub-transition layer in contact with the light-emitting epitaxial layer 300 is AlGaInAsP. That is, the first etch transition layer 210 is an AlGaInAsP layer; the etch stop layer 230 includes at least one sub-stop layer superimposed along the direction from the substrate 100 to the etch composite layer 200, and each sub-stop layer is one of AlGaInP, GaInP, and AlInP; the second etch transition layer 220 includes at least one sub-transition layer superimposed along the direction from the substrate 100 to the etch composite layer 200, and each sub-transition layer is an AlGaInAsP layer or AlGaInP, and the material of the sub-transition layer in contact with the light-emitting epitaxial layer 300 is AlGaInAsP. This application does not impose specific limitations on this.

[0046] Based on the same inventive concept, this application also provides a method for fabricating an epitaxial structure of a light-emitting diode (LED), used to fabricate the epitaxial structure of the LED provided in any of the above embodiments. (Reference) Figure 5 The diagram shows a flowchart of a method for fabricating an epitaxial structure of a light-emitting diode according to an embodiment of this application. The fabrication method provided in this embodiment includes:

[0047] S1, Provide a substrate.

[0048] S2. An etching composite layer is grown on the growth surface of the substrate. The etching composite layer includes a first etching transition layer, an etching stop layer, and a second etching transition layer. The etching stop layer is located on the side of the first etching transition layer away from the substrate, and the second etching transition layer is located on the side of the etching stop layer away from the substrate.

[0049] S3. A light-emitting epitaxial layer is grown on the side of the etched composite layer away from the substrate, wherein the lattice mismatch between the first etch transition layer and the substrate is less than the lattice mismatch between the etch stop layer and the substrate; and the lattice mismatch between the second etch transition layer and the light-emitting epitaxial layer is less than the lattice mismatch between the etch stop layer and the light-emitting epitaxial layer.

[0050] refer to Figure 6 The diagram shows a flowchart of another method for fabricating an epitaxial structure of a light-emitting diode according to an embodiment of this application. After the growth of the etched composite layer is completed in step S2, and before the growth of the light-emitting epitaxial layer in step S3, the fabrication method further includes:

[0051] S21. Phosphine and arsine are introduced into the growth chamber of the epitaxial structure of the light-emitting diode. The flow rate of the phosphine gradually decreases from a first set flow rate to a second set flow rate, while the flow rate of the arsine gradually increases from a third set flow rate to a fourth set flow rate. It can be understood that introducing phosphine and arsine into the growth chamber of the epitaxial structure of the light-emitting diode is equivalent to surface passivation and compositional smoothing of the second etching transition layer. That is, after the growth of the second etching transition layer is completed, and during the pause in growth before the growth of the light-emitting epitaxial layer, protective gases of phosphine and arsine are introduced to prevent surface decomposition or oxidation of the second etching transition layer. Furthermore, the flow rate of phosphine decreases while the flow rate of arsine increases, representing a gradual transition from phosphorus-rich to arsenic-rich, which gradually changes the surface atomic composition of the second etching transition layer. This is crucial for the subsequent growth of the light-emitting epitaxial layer on the second etching transition layer. This gradual process significantly improves the lattice matching and interface quality of the heterostructure, reduces interface defects and stress, and further improves the white edge problem caused by the accumulation of these defects and stresses in the edge region. Optionally, in the embodiments of this application, the first set flow rate is 600-1200 sccm, the second set flow rate is 1 sccm, the third set flow rate is 1 sccm, and the fourth set flow rate is 300-800 sccm.

[0052] refer to Figure 7The diagram shows a flowchart of another method for fabricating an epitaxial structure of a light-emitting diode (LED) according to an embodiment of this application. After the growth of the etched composite layer is completed in step S2, and before the growth of the light-emitting epitaxial layer in step S3; or, after phosphine and arsine are introduced into the growth chamber of the LED epitaxial structure in step S21, and before the growth of the light-emitting epitaxial layer in step S3, the fabrication method provided in this application further includes:

[0053] S22. Pause the growth process, raise the temperature of the growth chamber of the epitaxial structure of the light-emitting diode to a set temperature, and then lower it to the temperature for growing the second etch transition layer. It is understood that raising the temperature to the set temperature helps to drive away residual impurities, remove trace impurities adsorbed on the epitaxial surface, promote atomic migration / rearrangement, and allow atoms near the interface to gain energy and migrate to more stable positions, thereby achieving the purposes of repairing minor defects, smoothing the interface, and releasing stress, alleviating local stress caused by compositional changes or lattice mismatch. Lowering the temperature to the temperature for growing the second etch transition layer prepares for subsequent growth at a more optimized temperature. This temperature cycle is particularly helpful in improving the interface quality of the edge region. Optionally, the growth temperature of the first etch transition layer, the growth temperature of the etch stop layer, and the growth temperature of the second etch transition layer provided in this embodiment are 700-750℃, and the set temperature is not less than 800℃.

[0054] In summary, this application provides an epitaxial structure of a light-emitting diode and a method for fabricating the same. The epitaxial structure of the light-emitting diode includes: a substrate; an etch composite layer located on the growth surface of the substrate, the etch composite layer including a first etch transition layer, an etch stop layer, and a second etch transition layer, the etch stop layer being located on the side of the first etch transition layer away from the substrate, and the second etch transition layer being located on the side of the etch stop layer away from the substrate; and a light-emitting epitaxial layer located on the side of the etch composite layer away from the substrate, wherein the lattice mismatch between the first etch transition layer and the substrate is less than the lattice mismatch between the etch stop layer and the substrate; and the lattice mismatch between the second etch transition layer and the light-emitting epitaxial layer is less than the lattice mismatch between the etch stop layer and the light-emitting epitaxial layer.

[0055] As can be seen from the above, the epitaxial structure of the light-emitting diode provided in this application inserts a first etch transition layer with a small lattice mismatch with the substrate and a second etch transition layer with a small lattice mismatch with the light-emitting epitaxial layer on both sides of the etch stop layer. This results in a high lattice matching degree between the etch composite layer and the substrate and the light-emitting epitaxial layer, thereby improving the crystal growth quality of the light-emitting epitaxial layer, improving the white edge problem on the surface of the light-emitting epitaxial layer, and improving the performance and yield of the subsequently fabricated light-emitting diode.

[0056] In the description of the embodiments of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of the embodiments of this application, unless otherwise specified, numerical ranges excluding endpoint values ​​are included.

[0057] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of embodiments of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0058] In the embodiments of this application, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0059] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0060] In the embodiments of this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An epitaxial structure for a light-emitting diode, characterized in that, include: Substrate; An etch composite layer is located on the growth surface of the substrate. The etch composite layer includes a first etch transition layer, an etch stop layer, and a second etch transition layer. The etch stop layer is located on the side of the first etch transition layer away from the substrate, and the second etch transition layer is located on the side of the etch stop layer away from the substrate. The light-emitting epitaxial layer is located on the side of the etched composite layer away from the substrate, wherein the lattice mismatch between the first etch transition layer and the substrate is less than the lattice mismatch between the etch stop layer and the substrate; and the lattice mismatch between the second etch transition layer and the light-emitting epitaxial layer is less than the lattice mismatch between the etch stop layer and the light-emitting epitaxial layer.

2. The epitaxial structure of the light-emitting diode according to claim 1, characterized in that, The epitaxial structure of the light-emitting diode also includes: A buffer layer is located between the substrate and the etch composite layer, wherein the lattice mismatch between the first etch transition layer and the buffer layer is less than the lattice mismatch between the etch stop layer and the buffer layer.

3. The epitaxial structure of the light-emitting diode according to claim 2, characterized in that, The buffer layer is a GaAs buffer layer.

4. The epitaxial structure of the light-emitting diode according to claim 2, characterized in that, The lattice mismatch between the first corrosion transition layer and the buffer layer is less than 0.01%.

5. The epitaxial structure of the light-emitting diode according to claim 1, characterized in that, The first etch transition layer is an AlGaInAsP layer; The etching stop layer includes at least one sub-stop layer stacked along the direction from the substrate to the etching composite layer, and each sub-stop layer is one of AlGaInP layer, GaInP layer, and AlInP layer. The second etch transition layer includes at least one sub-transition layer stacked along the direction from the substrate to the etch composite layer, each of the sub-transition layers being an AlGaInAsP layer or an AlGaInP layer, and the sub-transition layer in contact with the light-emitting epitaxial layer being an AlGaInAsP layer.

6. The epitaxial structure of the light-emitting diode according to claim 1, characterized in that, The thickness of the first corrosion transition layer and the thickness of the second corrosion transition layer are both less than the thickness of the corrosion stop layer.

7. The epitaxial structure of the light-emitting diode according to claim 1, characterized in that, The light-emitting epitaxial layer includes a first type of semiconductor confinement layer, an active layer, and a second type of semiconductor confinement layer. The active layer is located on the side of the first type of semiconductor confinement layer away from the substrate, and the second type of semiconductor confinement layer is located on the side of the active layer away from the substrate.

8. The epitaxial structure of the light-emitting diode according to claim 7, characterized in that, The light-emitting epitaxial layer further includes: An at least one of the following is disposed between the etched composite layer and the first type of semiconductor confinement layer, and sequentially stacked along the direction from the substrate to the etched composite layer: an ohmic contact layer, a current transport layer, a roughening layer, and a first type of semiconductor current spreading layer.

9. The epitaxial structure of a light-emitting diode according to claim 8, characterized in that, The lattice mismatch between the second corrosion transition layer and the ohmic contact layer is less than the lattice mismatch between the corrosion stop layer and the ohmic contact layer.

10. The epitaxial structure of the light-emitting diode according to claim 7, characterized in that, The light-emitting epitaxial layer further includes: A second type of semiconductor current spreading layer located on the side of the second type of semiconductor confinement layer opposite to the substrate.

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