Light emitting diode and light emitting device

Abstract

The present application provides a light-emitting diode and a light-emitting device. The light-emitting diode includes a light-emitting structure, including an electrode structure of a first electrode and a second electrode, the first electrode is electrically connected to the N-type semiconductor layer of the light-emitting structure, and the second electrode is electrically connected to the P-type semiconductor layer of the light-emitting structure; the light-emitting structure is formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa includes a widened portion located in the middle part, and strip portions extending from both ends of the widened portion to both sides of the light-emitting structure, and the surface area of ​​the N-type mesa accounts for 30% to 50% of the surface area of ​​the light-emitting structure. The above structure of the N-type mesa increases the area ratio of the N-type region, which is beneficial to increase the area of ​​the N-type contact formed subsequently, and is beneficial to reducing the voltage of the device. In addition, the N-type mesa is generally symmetrical about its center line, so it is beneficial to the light emitting type of the light-emitting diode and the light emitting from the side wall.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices and apparatuses, and in particular to a light emitting diode and a light emitting apparatus. Background Art

[0002] In recent years, the huge application value of ultraviolet LEDs, especially deep ultraviolet LEDs, has attracted great attention and has become a new research hotspot. Compared with blue LEDs, short-wavelength light-emitting diodes that emit ultraviolet light have a semiconductor layer with a high Al composition, resulting in high contact resistance between the n-type semiconductor layer and the n-type electrode of the ultraviolet light-emitting diode. Therefore, it is necessary to provide an n-contact electrode with a sufficient area to prevent the increase of the forward voltage of the light-emitting diode. Summary of the invention

[0003] The present invention provides a light emitting diode and a light emitting device, wherein the light emitting diode can prevent an increase in forward voltage caused by components of a semiconductor layer and can improve reliability.

[0004] One embodiment of the present invention provides a light emitting diode, comprising:

[0005] A light emitting structure, the light emitting structure comprising an N-type semiconductor layer, a P-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, the light emitting structure being formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa comprising a widened portion located in the middle portion, and strip portions extending from both ends of the widened portion to both sides of the light emitting structure;

[0006] An electrode structure, the electrode structure comprising a first electrode and a second electrode, the first electrode being formed on the N-type mesa and electrically connected to the N-type semiconductor layer, the second electrode being electrically connected to the P-type semiconductor layer, wherein a projection area of ​​the first electrode on the light-emitting structure accounts for 25% to 60% of an area of ​​the light-emitting structure;

[0007] an insulating layer formed on the surface of the light emitting structure;

[0008] The first electrode includes a main body located in the widened portion of the N-type table and a finger-shaped portion located in the strip-shaped portion. The finger-shaped portion extends from both sides of the main body. In a direction perpendicular to the extension of the finger-shaped portion, the width of the main body is greater than the width of the finger-shaped portion.

[0009] Optionally, the light-emitting diode also includes a pad structure, which includes a first pad electrically connected to the first electrode and a second pad electrically connected to the second electrode, the first pad is located above the finger-shaped portion, and the first pad and the second pad are located at both ends of the light-emitting structure.

[0010] Optionally, a projection of the pad structure on the light-emitting structure does not overlap with the widened portion.

[0011] Optionally, the first pad and the second pad are located at two ends of the light emitting structure and are symmetrically arranged.

[0012] Optionally, a boss structure is further formed in the N-type mesa, the boss structure includes an N-type semiconductor layer, a P-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, and the boss structure is insulated from the first electrode.

[0013] Optionally, the boss structure is formed in a region where the widened portion is located, and a cross-sectional area of ​​the boss structure is smaller than a cross-sectional area of ​​the widened portion.

[0014] Optionally, the light-emitting diode further includes a pin adsorption area, the pin adsorption area is formed in a region corresponding to the widened portion, the pin adsorption area includes a metal layer formed above the insulating layer, and the metal layer is spaced apart from the first pad and the second pad.

[0015] Optionally, the light-emitting diode also includes a pin adsorption area, which is formed in an area corresponding to the widened portion, and the pin adsorption area includes a metal boss formed above the insulating layer, the metal boss is spaced apart from the first pad and the second pad, and the metal boss is flush with the first pad and the second pad.

[0016] Optionally, the metal layer in the ejector pin adsorption area is formed simultaneously with the pad structure.

[0017] Optionally, an upper surface of the metal boss is flush with an upper surface of the pad structure.

[0018] Optionally, the n-type semiconductor layer has Al x Ga 1-x N represents a layer of composition, where 0.5≤x≤0.65.

[0019] According to another embodiment of the present invention, there is provided a light emitting diode, comprising:

[0020] A light emitting structure, the light emitting structure comprising an N-type semiconductor layer, a P-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, the light emitting structure is formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa comprises a widening portion located in the middle part, and strip portions extending from both ends of the widening portion to both sides of the light emitting structure, and in a direction perpendicular to the extension of the strip portion, the width of the widening portion is greater than the width of the strip portion;

[0021] a first electrode and a second electrode, wherein the first electrode is formed on the N-type mesa and electrically connected to the N-type semiconductor layer, and the second electrode is electrically connected to the P-type semiconductor layer;

[0022] an insulating layer formed on the surface of the light emitting structure;

[0023] a pad structure, the pad structure comprising a first pad electrically connected to the first electrode and a second pad electrically connected to the second electrode, the first pad being located above the finger-shaped portion, and the first pad and the second pad being located at two ends of the light emitting structure;

[0024] Wherein, a projection of the first pad on the light-emitting structure does not overlap with the widened portion.

[0025] Optionally, the emission wavelength of the active layer is below 360 nm.

[0026] Optionally, the N-type semiconductor layer has Al x Ga 1-x N represents a layer of composition, where 0.5≤x≤0.65.

[0027] Optionally, a projection of the second pad on the light emitting structure does not overlap with the N-type mesa.

[0028] Optionally, a projection area of ​​the first electrode on the light emitting structure accounts for 25% to 60% of an area of ​​the light emitting structure.

[0029] Optionally, the first electrode includes a first contact electrode and a first protective electrode, the first contact electrode contacts the N-type semiconductor layer, and the first protective layer covers the first contact electrode.

[0030] Optionally, the first contact electrode is Ti—Al—Au alloy, Ti—Al—Ni—Au alloy, Cr—Al—Ti—Au alloy, Ti—Al—Au—Pt alloy, Ti—Ru—Au—Al alloy or Ti—Al—Pt alloy.

[0031] According to another embodiment of the present invention, a light emitting device is provided, which includes a circuit substrate and a light emitting element fixed on the circuit substrate, wherein the light emitting element is the light emitting diode provided by the present invention.

[0032] As described above, the light emitting diode and the light emitting device of the present application have the following beneficial effects:

[0033] The light-emitting diode of the present application includes a light-emitting structure, including an electrode structure of a first electrode and a second electrode, the first electrode is electrically connected to the N-type semiconductor layer of the light-emitting structure, and the second electrode is electrically connected to the P-type semiconductor layer of the light-emitting structure; the light-emitting structure is formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa includes a widened portion located in the middle part, and strip portions extending from both ends of the widened portion to both sides of the light-emitting structure, and the surface area of ​​the N-type mesa accounts for 30% to 50% of the surface area of ​​the light-emitting structure. The above structure of the N-type mesa increases the area ratio of the N-type region, which is beneficial to increase the contact area of ​​the N-type electrode formed subsequently, and is beneficial to reducing the voltage of the device. In addition, the above setting of the N-type mesa makes the light-emitting area of ​​the chip roughly symmetrical about the center line of the chip, which is beneficial to the light-emitting light type of the light-emitting diode and the light emitting from the side wall.

[0034] The first electrode is formed on the N-type mesa and includes a main body and a finger-shaped portion electrically connected to each other. The main body is located in the middle area of ​​the light-emitting diode, and the finger-shaped portion extends from both sides of the main body. In the direction perpendicular to the extension of the finger-shaped portion, the width of the main body is greater than the width of the finger-shaped portion. The first pad is formed above the finger-shaped portion, and the projection on the light-emitting structure does not overlap with the widened portion, which is conducive to reducing the height difference of the first pad surface and increasing the area of ​​the pad structure, thereby increasing the thrust of the pad, which is conducive to improving the reliability and yield of subsequent devices.

[0035] The light-emitting diode also includes a pin adsorption area, and in the thickness direction of the light-emitting diode, the pin adsorption area corresponds to the main body of the first electrode. Therefore, the pin adsorption area is located above the main body of the first electrode as a whole, and there is no height difference in the first main body. Therefore, during the eutectic process, the pin can adsorb the chip well without causing damage to the chip. The pin adsorption area can be a metal layer, and the metal layer can be formed by vapor deposition at the same time as the pad structure of the light-emitting diode, without adding additional processes, which is conducive to cost saving.

[0036] In addition, in the process of etching the light-emitting structure to form the N-type mesa, a part of the light-emitting structure can be retained in the area where the main body of the light-emitting diode is located to form a convex structure, which can play a role in current blocking, which is beneficial to the distribution of current in the light-emitting diode, improves the light extraction rate of the light-emitting diode, and is beneficial to improving the side wall light extraction of the light-emitting diode and improving the light extraction light type. The convex structure is a flat structure as a whole, without height difference, which is beneficial to further reduce the height difference of the chip surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the planar structure of a light emitting diode in the prior art.

[0038] Figure 2a Shown is a schematic diagram of the planar structure of a light emitting diode provided in Example 1 of the present application.

[0039] Figure 2b Shown is a schematic diagram of the planar structure of a light emitting diode in an optional embodiment of the first embodiment.

[0040] Figure 3 Display as Figure 2a A schematic top view of the light emitting structure of the light emitting diode is shown.

[0041] Figure 4 Display as Figure 2a Cross-sectional view along the midline L1-L1.

[0042] Figure 5 Display as Figure 2a Cross-sectional view along the midline L2-L2.

[0043] Figure 6 Display as Figure 2a Cross-sectional view along the midline L3-L3.

[0044] Figure 7 Display as Figure 2a Cross-sectional view along the midline L4-L4.

[0045] Figure 8 Shown is a cross-sectional view of a light emitting diode provided in the second embodiment of the present application.

[0046] Fig. 9 The cross-sectional view of a light emitting diode in an alternative embodiment of the second embodiment is shown.

[0047] Fig.10 Shown is a schematic diagram of the planar structure of a light emitting diode provided in Example 3 of the present application.

[0048] Fig.11 Display as Fig.10 A schematic top view of the light emitting structure of the light emitting diode is shown.

[0049] Fig.12 Display as Fig.10 Cross-sectional view along the midline L5-L5.

[0050] Fig.13 Shown is a schematic diagram of the structure of the light-emitting device provided in Example 4 of the present application.

[0051] Component number description

[0052] 01 N-pole pad 10511 First contact electrode

[0053] 001 Main body 10512 First protective electrode

[0054] 002 Finger 1051-1 Main body

[0055] 02 P-pole pad 1051-2 finger-shaped part

[0056] 100 light emitting diode 1052 second electrode

[0057] 101 substrate 10521 second contact electrode

[0058] 102 light emitting structure 10522 second protective electrode

[0059] 1021 N-type semiconductor layer 106 metal layer

[0060] 1022 P-type semiconductor layer 107 metal boss

[0061] 1023 active layer 108 convex structure

[0062] 103 Insulation layer 110 Ejector pin adsorption area

[0063] 1041 First pad 120 N-type mesa

[0064] 1042 second pad 1201 widened portion

[0065] 1051 first electrode 1202 strip portion DETAILED DESCRIPTION

[0066] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the 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.

[0067] Figure 1An existing ultraviolet light-emitting diode is shown. The light-emitting diode forms an N-type electrode on an N-type table (formed by etching the P-type semiconductor layer, active layer and part of the N-type semiconductor layer of the light-emitting structure), and the N-type electrode includes a body portion 001 and a finger portion 002. The body portion 001 is located at one end of the light-emitting diode and below the N-pole pad 01, and the finger portion 002 extends from the body portion 001 to the opposite end of the P-pole pad 02. The light-emitting diode can increase the contact area between the N-type electrode and the N-type semiconductor layer through the finger portion.

[0068] Most of the N-pole pad 01 of the light-emitting diode overlaps with the N-type mesa, resulting in a large area of ​​height difference on the electrode surface. This height difference will reduce the thrust of the electrode, making the chip prone to failure during eutectic packaging, affecting the product yield or the reliability of subsequent devices.

[0069] In addition, during the chip bonding process, a pin is usually used to push the chip in the middle to facilitate chip grabbing. Since the finger-shaped portion 02 of the N-type electrode of the light-emitting diode is located in the middle area of ​​the light-emitting diode surface, the center of the chip is a non-flat area, so it is easy to be damaged during the chip grabbing process, resulting in chip failure.

[0070] In order to solve the above problems, the following embodiments provide a light emitting diode and a light emitting device, which are now described in detail in conjunction with the following drawings.

[0071] Embodiment 1

[0072] This embodiment provides a light emitting diode, taking an ultraviolet light emitting diode as an example. Figure 2a and Figure 4 As shown, the light emitting diode 100 includes a light emitting structure 102, and the light emitting structure 102 includes an N-type semiconductor layer 1021, a P-type semiconductor layer 1022, and an active layer 1023 located between the N-type semiconductor layer 1021 and the P-type semiconductor layer 1022. In an optional embodiment, the light emitting diode 100 may include a substrate 101, and the light emitting structure 102 is formed above the substrate 101.

[0073] In this embodiment, the N-type semiconductor layer 1021 is an N-type nitride layer, such as an n-type GaN layer or an n-type AlGaN layer, for providing electrons. The N-type semiconductor layer 1021 provides electrons by doping with n-type impurities, such as Si, Ge, Sn, Se and Te. In this embodiment, the preferred n-type impurity is Si. The thickness of the N-type semiconductor layer 1021 is about 1 to 4 μm, and the doping concentration is 1×10 18 Atoms / cm 3 ~5×10 19 Atoms / cm 3The N-type semiconductor layer 1021 may be a single-layer structure or a multi-layer structure, for example, may include a super lattice structure.

[0074] In a specific embodiment, the light emitting diode emits ultraviolet light in the UV-B wavelength range (315nm to 280nm) or the UV-C wavelength range (less than 280nm). The N-type semiconductor layer 1021 is a layer mainly composed of AlGaN. The donor contained in the N-type semiconductor layer is, for example, Si. The AlGaN constituting the N-type semiconductor layer 1021 has a composition such that the N-type semiconductor layer 1021 does not absorb light emitted from the active layer. In detail, the higher the Al composition, the wider the band gap becomes, and thus the N-type semiconductor layer 1021 absorbs less light of shorter wavelengths. If the emission wavelength of the active layer 1023 is set in the UV-B wavelength range, the N-type semiconductor layer 1021 may have a layer of a composition represented by AlxGa1-xN (0.5≤x≤0.65). In this case, since it is easier to grow high-quality crystals when AlGaN with a lower Al composition is used, the composition of the N-type semiconductor layer 1021 is preferably AlxGa1-xN (0.5≤x≤0.55). If the emission wavelength of the active layer 1023 is set within the UV-C wavelength range, the N-type semiconductor layer 1021 may have a composition represented by AlxGa1-xN (0.65≤x≤1). In this case, since it is easier to grow high-quality crystals when AlGaN with a lower Al composition is used, the composition of the N-type semiconductor layer 1021 is preferably AlxGa1-xN (0.65≤x≤0.7).

[0075] An active layer 1023 is formed above the N-type semiconductor layer 1021 to provide an area for electrons and holes to recombine and provide light radiation. Different materials can be selected according to different luminescent wavelengths. The active layer 1023 can be a periodic structure of a single quantum well or multiple quantum wells. In this embodiment, the active layer 1023 is preferably a layer that emits ultraviolet rays, and has a well layer and a barrier layer. The number of repetitions of the well layer and the barrier layer is, for example, greater than 1 and less than 10. The well layer is, for example, an AlGaN layer, and the barrier layer is, for example, an AlGaN layer, but the Al composition of the well layer is lower than the Al composition of the barrier layer. By adjusting the composition ratio of the semiconductor material in the active layer 1023, it is expected to radiate light of different wavelengths. In this embodiment, the emission wavelength of the active layer 1023 is less than 360nm.

[0076] A P-type semiconductor layer 1022 is formed above the active layer 1023, wherein the P-type semiconductor layer 1022 is a P-type nitride layer, such as a p-type AlGaN layer or a p-type GaN layer, or a multilayer structure formed by stacking a p-type AlGaN layer and a p-type GaN layer in sequence. Holes are provided by doping with P-type impurities, and the P-type impurities may be Mg, Zn, Ca, Sr, and Ba. In this embodiment, the P-type impurity is preferably Mg.

[0077] A P-type ohmic contact layer may also be formed on the P-type semiconductor layer 1022 by high doping, for example, a doping concentration higher than 1×10 20 Atoms / cm 3 , forming an ohmic contact with the P-type electrode of the subsequently formed nitride light-emitting diode. Preferably, the thickness of the P-type ohmic contact layer is 5 to 50 nm. By setting a thin-film ohmic contact layer, the internal quantum luminescence efficiency and the external quantum luminescence efficiency of the device can be taken into account. Specifically, the ohmic contact layer within this thickness range is conducive to the lateral current expansion of the p-side current without causing excessive light absorption.

[0078] like Figure 3 As shown, the light emitting structure 102 includes an N-type mesa 120, which is formed by etching away a portion of the P-type semiconductor layer 1022 and the active layer 1023 to expose a portion of the surface of the N-type semiconductor layer 1021. The N-type mesa 120 can also be formed by etching away a portion of the N-type semiconductor layer 1021 at the same time. Figure 3 As shown, the N-type mesa 120 includes a widening portion 1201 located in the middle of the light emitting structure 102 and strip portions 1202 extending from both ends of the widening portion 1201 to both ends of the light emitting structure 102, that is, the strip portions 1202 extending from both ends of the widening portion 1201 to both ends of the light emitting structure 102. Figure 3 Optionally, the strip portion 1202 may also extend in the Y direction. Figure 3 The Y direction shown extends from one end of the widened portion 1201 , and preferably, extends from the widened portion 1201 in a direction toward forming the first pad.

[0079] Likewise Figure 3 As shown, in the extension direction perpendicular to the strip portion 1202, that is, Figure 3 In the X direction shown, the width d1 of the widened portion 1201 is greater than the width d2 of the strip portion 1202, thereby forming the widened portion 1201 extending to both sides of the light emitting structure 102. The formation of the N-type mesa 120 is beneficial to increase the contact area of ​​the N-type electrode formed subsequently, and is beneficial to reducing the voltage of the device. In addition, the above structure of the N-type mesa 120 makes the light emitting surface area of ​​the light emitting structure 102 substantially symmetrical about the center line of the light emitting diode 100, which is beneficial to the light emitting light type of the light emitting diode 100 and the light emitting from the side wall.

[0080] Likewise Figure 2a , Figure 4 and Figure 5 and Figure 6 As shown, the light emitting diode 100 further includes an electrode structure, which includes a first electrode 1051 and a second electrode 1052, wherein the first electrode 1051 is formed on the N-type mesa 120 of the light emitting structure 102 and is electrically connected to the N-type semiconductor layer 1021. The second electrode 1052 is formed above the P-type semiconductor layer 1022 and is electrically connected to the P-type semiconductor layer 1022.

[0081] In a specific embodiment, the first electrode 1051 preferably includes a first contact electrode 10511 and a first protective electrode 10512. The first contact electrode 10511 is selected from one or more of Cr, Pt, Au, Ni, Ti, and Al. Since the N-type semiconductor layer has a relatively high Al component, the N-type contact electrode needs to be fused at high temperature to form an alloy after being deposited on the table, so as to form a good ohmic contact with the N-type semiconductor layer, for example, it can be Ti-Al-Au alloy, Ti-Al-Ni-Au alloy, Cr-Al-Ti-Au alloy, Ti-Al-Au-Pt alloy, Ti-Ru-Au-Al alloy or Ti-Al-Pt alloy. The first protective electrode 10512 is formed on the first contact electrode 10522, and is preferably a multi-layer metal stack, for example, an adhesion layer, a conductive layer, etc. are sequentially deposited on the contact electrode. Preferably, the first protection electrode 10512 completely covers the first contact electrode 10511 , which can increase the height of the N-type mesa region on the one hand, and protect the first contact electrode 10511 on the other hand.

[0082] In a specific embodiment, the second electrode 1052 preferably includes a second contact electrode 10521 and a second protective electrode 10522. The second contact electrode 10521 is formed in contact on the surface of the P-type semiconductor layer 1022 to form an ohmic contact with the P-type semiconductor layer 1022. Preferably, the material of the second contact electrode 10522 can be an oxide transparent conductive material, and its thickness is preferably less than 30nm, so as to reduce the light absorption rate of the layer as much as possible. The second contact electrode 10522 can also be made of metal alloys such as NiAu, NiAg, and NiRh, so that a reflective electrode can be formed to improve the light extraction efficiency of the light-emitting diode.

[0083] Since the light emitting diode 100 of the present embodiment emits ultraviolet light in the UV-B wavelength range or the UV-C wavelength range, the AlGaN constituting the N-type semiconductor layer has a high Al component to reduce the absorption of the N-type semiconductor layer to short-wavelength ultraviolet light. Due to the high Al component, the contact resistance between the N-type semiconductor layer and the first electrode is very high, so the area of ​​the first electrode 1051 (the contact area with the N-type semiconductor layer) is preferably not less than 25% of the area of ​​the light emitting structure 102 to avoid an increase in the forward voltage. Because the N-type mesa 120 in the structure of the light emitting diode 100 increases with the increase in the area of ​​the first electrode 1051, the area of ​​the corresponding active region 1023 decreases with the increase in the area of ​​the N-type mesa 120, and the reduction in the area of ​​the active layer 1023 causes a reduction in the light emitting area, the area of ​​the first electrode 1051 is preferably not more than 60% of the area of ​​the light emitting structure 102. In order to increase the area of ​​the active layer 1023 as much as possible, the area of ​​the first electrode 1051 is preferably not less than 50% of the area of ​​the N-type mesa 120, for example, it can be 50% to 90%. When the area of ​​the first electrode 1051 exceeds 90% of the area of ​​the N-type mesa 120, the reliability of the light-emitting diode is easily reduced. In a specific embodiment, the contact area between the first electrode 1051 and the N-type semiconductor layer 1021 is 30% to 45% of the area of ​​the light-emitting structure 102.

[0084] A pad structure is formed above the electrode structure, and the pad structure includes two pads located at two ends of the light emitting diode 100 (i.e. Figure 2a and Figure 3 The first pad 1041 and the second pad 1042 are electrically connected to the first electrode 1051 and the second pad 1042 are electrically connected to the second electrode 1052. An insulating layer 103 is formed on the surface of the light emitting structure 102 (including the exposed surface of the N-type mesa 120 and the surface of the first electrode 1051). The electrical connection between the pad structure and the electrode structure can be achieved through the through hole in the insulating layer 103.

[0085] like Figure 2a As shown, the first electrode 1051 is formed on the N-type mesa 120, so the first electrode 1051 includes a main body 1051-1 formed in the widened portion and a finger-shaped portion 1051-2 formed in the strip-shaped portion 1202. The finger-shaped portion 1051-2 extends from both ends of the main body 1051-1 to both ends of the light-emitting diode 100, that is, at Figure 2a In the Y direction shown, the light emitting diode 100 is extended to both ends. In the extending direction perpendicular to the finger-shaped portion 1051-2, that is, Figure 2a In the X direction shown, the width of the finger portion 1051-2 is smaller than the width of the main body portion 1051-1, and the main body portion 1051-1 expands toward both sides of the light emitting diode 100 in the X direction. Figure 4 As shown, an insulating layer 103 is also formed above the electrode structure. It is understandable that an insulating layer 103 is also formed between the first electrode 1051 and the side wall of the N-type mesa 120, and on the retained N-type mesa 120. The above-mentioned insulating layer 103 can be the same material or different materials, for example, both can be SiO2 layers. As mentioned above, since the main body 1051-1 of the first electrode 1051 is formed in the middle part of the light-emitting diode 100, the area of ​​the recessed area in the edge area of ​​the light-emitting diode 100 can be reduced, which is beneficial to the subsequent production of pads in the edge area of ​​the light-emitting diode 100. At the same time, a relatively flat surface can be formed in the middle area of ​​the light-emitting diode 100, and the flat surface is beneficial to the subsequent use as the top pin adsorption area 110. Similarly, Figure 2a As shown, the light emitting diode 100 further includes a pad structure formed on the surface of the light emitting diode 100, the pad structure including a first pad 1041 and a second pad 1042, the first pad 1041 is electrically connected to the first electrode 1051, the second pad 1042 is electrically connected to the second electrode 1052, and the first pad 1041 is formed above the finger-shaped portion 1051-2 of the first electrode 1051. Preferably, as Figure 2a As shown, the first electrode 1051 and the second electrode 1052 are symmetrically arranged at two ends of the light emitting diode 100 .

[0086] In an optional embodiment, the projection of the pad structure on the light emitting structure does not overlap with the widened portion 1201 of the n-type mesa 120. Figure 2b As shown, the projection of the first pad 1041 on the light-emitting structure does not overlap with the widened portion 1201, and the projection of the second pad 1042 on the light-emitting structure does not overlap with the n-type table 120, that is, the second pad 1042 and the first electrode 1051 are staggered with each other, which helps to avoid short circuits caused by rupture of the insulating layer above the electrode.

[0087] Since the main body 1051-1 of the first electrode 1051 is formed in the middle area, the finger-shaped parts 1051-2 are formed on both sides of the main body 1051-1. Figure 5 2 does not pass through the first electrode 1051, in the area outside the first electrode 1051, the surface of the light emitting diode 100 is a flat surface, such as Figure 6 and Figure 7As shown, the light emitting diode 100 forms a recessed area above the main body 1051-1 and the finger-shaped part 1051-2, and the recessed area above the finger-shaped part 1050-2 near the edge of the light emitting diode 100 is significantly smaller than the recessed area above the main body 1051-1. Therefore, the edge area of ​​the light emitting diode 100 has a relatively large flat surface, which is conducive to the formation of the pad structure. The overall flatness of the formed pad structure is increased, which is conducive to increasing the thrust of the chip after die bonding, making it difficult for the chip to fall off, and enhancing the yield and reliability of subsequent devices or equipment.

[0088] Embodiment 2

[0089] This embodiment also provides a light emitting diode, such as Figure 8 As shown, the light emitting diode 100 further includes a pin adsorption area 110. In this embodiment, the pin adsorption area 110 includes a metal layer 106 formed in the middle area of ​​the light emitting diode 100. The metal layer 106 is preferably formed simultaneously with the pad structure. For example, while the pad metal is evaporated to form the pad structure, the pad metal is simultaneously evaporated in the middle area of ​​the light emitting diode 100 to form the metal layer 106. In the thickness direction of the light emitting diode 100, the metal layer 106 corresponds to the main body 1051-1 of the first electrode 1051. The metal layer 106 has the same thickness as the pad structure, but since the metal layer 106 is formed in the recessed area on the surface of the light emitting diode 100 corresponding to the main body 1051-1, the upper surface of the metal layer 106 is lower than the upper surface of the pad structure. At the same time, since there is no height difference on the surface of the light emitting diode 100 corresponding to the main body 1051-1 as a whole, it is convenient for the nozzle to absorb the chip, and when the pin is fixed on the metal layer 106, it will not cause damage to the chip.

[0090] In an alternative embodiment, if Fig. 9 As shown, in this embodiment, a metal boss 107 is formed in the ejector pin adsorption area 110. The metal boss 107 is spaced apart from the first pad 1041 and the second pad 1042, and the upper surface of the metal boss 107 is flush with the upper surface of the pad structure. Compared with the metal layer 106 in the first embodiment, the thickness of the metal boss 107 is significantly increased, which is more conducive to protecting the chip from damage by the ejector pin during the ejector pin adsorption process.

[0091] Embodiment 3

[0092] This embodiment also provides a light emitting diode, and the light emitting diode of this embodiment also includes a light emitting structure 102, an electrode structure, etc. The same points as those of the first embodiment will not be repeated, and the difference is that:

[0093] like Fig.10 and Fig.11As shown, the light emitting diode 100 of this embodiment has a protruding structure 108 formed in the widened portion of the N-type mesa 120. The protruding structure 108 also includes an active layer 1023 and a P-type semiconductor layer 1022, or includes an active layer 1023, a P-type semiconductor layer 1022 and a portion of the N-type semiconductor layer 1021. When etching the N-type mesa 120, a shielding portion is formed in the area corresponding to the widened portion by adjusting the window of the mask, and then the light emitting structure 102 is etched to form the N-type mesa 120, and the protruding structure 108 is formed in the widened portion of the N-type mesa 120. Fig.11 As shown, in the projection on the substrate 101, the projection area of ​​the protruding structure 108 is smaller than the projection area of ​​the widened portion. The area of ​​the surface recessed region of the light-emitting diode 100 formed with the protruding structure 108 is further reduced, and the height difference is further reduced. The pad structure is the same as the pad structure of the first embodiment, and also has a very small recessed area. The pad structure as a whole can be regarded as having a flat surface, so it can effectively increase the thrust of the light-emitting diode and improve the reliability of the device after die bonding.

[0094] The surface of the protruding structure 108 is flat as a whole, which is conducive to the subsequent formation of an overall flat ejector adsorption area 110. In this embodiment, the ejector adsorption area 110 is formed with the metal layer 106 shown in the second embodiment at the corresponding position of the protruding structure 108. It can be understood that the ejector adsorption area 110 is formed with the metal boss 107 shown in the second embodiment at the corresponding position of the protruding structure 108.

[0095] Embodiment 4

[0096] This embodiment provides a light emitting device, such as Fig.13 As shown, the light emitting device includes a circuit substrate and a light emitting element fixed on the circuit substrate. The light emitting element may be the light emitting diode 100 in the first embodiment, the second embodiment or the third embodiment, or may be a combination of any two or more light emitting diodes 100 in the first embodiment, the second embodiment or the third embodiment. The light emitting diode 100 is fixed to the die-bonding area (not shown) of the circuit substrate through a pad structure. Since the area of ​​the recessed area on the surface of the light emitting diode 100 is reduced, the recessed area of ​​the pad structure is significantly reduced, and the surface can be regarded as a flat surface as a whole. Therefore, after die bonding, the thrust of the light emitting diode 100 is increased, and the reliability and yield of the light emitting device are correspondingly improved.

[0097] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A light emitting diode, characterized in that: include: A light emitting structure, the light emitting structure comprising an N-type semiconductor layer, a P-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, the light emitting structure being formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa comprising a widened portion located in the middle of the light emitting structure, and strip portions extending from both ends of the widened portion to both sides of the light emitting structure; An electrode structure, the electrode structure comprising a first electrode and a second electrode, the first electrode being formed on the N-type table and electrically connected to the N-type semiconductor layer, the second electrode being electrically connected to the P-type semiconductor layer, wherein a projection area of ​​the first electrode on the light-emitting structure accounts for 25% to 60% of an area of ​​the light-emitting structure; an insulating layer formed on the surface of the light emitting structure; The first electrode includes a main body located in the widened portion of the N-type table and a finger-shaped portion located in the strip-shaped portion, wherein the finger-shaped portion extends from both sides of the main body, and in a direction perpendicular to the extension of the finger-shaped portion, the width of the main body is greater than the width of the finger-shaped portion.

2. The light emitting diode according to claim 1, characterized in that: It also includes a pad structure, which includes a first pad electrically connected to the first electrode and a second pad electrically connected to the second electrode, the first pad is located above the finger-shaped portion, and the first pad and the second pad are located at both ends of the light-emitting structure.

3. The light emitting diode according to claim 2, characterized in that: A projection of the pad structure on the light emitting structure does not overlap with the widened portion.

4. The light emitting diode according to claim 2, characterized in that: The first pad and the second pad are located at two ends of the light emitting structure and are symmetrically arranged.

5. The light emitting diode according to claim 1, characterized in that: A boss structure is also formed in the N-type mesa, and the boss structure includes an N-type semiconductor layer, a P-type semiconductor layer, and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, and the boss structure is insulated from the first electrode.

6. The light emitting diode according to claim 5, characterized in that: The boss structure is formed in a region where the widened portion is located, and a cross-sectional area of ​​the boss structure is smaller than a cross-sectional area of ​​the widened portion.

7. The light emitting diode according to claim 2, characterized in that: It also includes a pin adsorption area, which is formed in a region corresponding to the widened portion. The pin adsorption area includes a metal layer formed above the insulating layer, and the metal layer is spaced apart from the first pad and the second pad.

8. The light emitting diode according to claim 2, characterized in that: It also includes a pin adsorption area, which is formed in an area corresponding to the widened portion. The pin adsorption area includes a metal boss formed above the insulating layer, the metal boss is spaced apart from the first pad and the second pad, and the metal boss is flush with the first pad and the second pad.

9. The light emitting diode according to claim 7, characterized in that: The metal layer in the ejector pin adsorption area is formed simultaneously with the pad structure.

10. The light emitting diode according to claim 8, characterized in that: The upper surface of the metal boss is flush with the upper surface of the pad structure.

11. The light emitting diode according to claim 1, characterized in that: The N-type semiconductor layer has Al x Ga 1-x N represents a layer of composition, where 0.5≤x≤0.

65.

12. A light emitting diode, characterized in that: include: A light emitting structure, the light emitting structure comprising an N-type semiconductor layer, a P-type semiconductor layer and an active layer located between the N-type semiconductor layer and the P-type semiconductor layer, the light emitting structure being formed with an N-type mesa to expose the N-type semiconductor layer, the N-type mesa comprising a widening portion located in the middle of the light emitting structure, and strip portions extending from both ends of the widening portion to both sides of the light emitting structure, wherein in a direction perpendicular to the extension of the strip portion, the width of the widening portion is greater than the width of the strip portion; a first electrode and a second electrode, wherein the first electrode is formed on the N-type mesa and electrically connected to the N-type semiconductor layer, and the second electrode is electrically connected to the P-type semiconductor layer; an insulating layer formed on the surface of the light emitting structure; a pad structure, the pad structure comprising a first pad electrically connected to the first electrode and a second pad electrically connected to the second electrode, the first pad being located above the strip portion, and the first pad and the second pad being located at two ends of the light emitting structure; Wherein, the projection of the first pad on the light-emitting structure does not overlap with the widened portion.

13. The light emitting diode according to claim 12, characterized in that The emission wavelength of the active layer is below 360 nm.

14. The light emitting diode according to claim 12, characterized in that: The N-type semiconductor layer has Al x Ga 1-x N represents a layer of composition, where 0.5≤x≤0.

65.

15. The light emitting diode according to claim 12, characterized in that: A projection of the second pad on the light emitting structure does not overlap with the N-type mesa.

16. The light emitting diode according to claim 12, characterized in that A projection area of ​​the first electrode on the light emitting structure accounts for 25% to 60% of an area of ​​the light emitting structure.

17. The light emitting diode according to claim 12, characterized in that: The first electrode includes a first contact electrode and a first protection electrode, the first contact electrode contacts the N-type semiconductor layer, and the first protection electrode covers the first contact electrode.

18. The light emitting diode according to claim 17, characterized in that: The first contact electrode is Ti—Al—Au alloy, Ti—Al—Ni—Au alloy, Cr—Al—Ti—Au alloy, Ti—Al—Au—Pt alloy, Ti—Ru—Au—Al alloy or Ti—Al—Pt alloy.

19. A light emitting device, characterized in that: It comprises a circuit substrate and a light-emitting element fixed on the circuit substrate, wherein the light-emitting element is the light-emitting diode according to any one of claims 1 to 18.

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