Light emitting diode and light emitting device

Abstract

The invention provides a light emitting diode and a light emitting device. A semiconductor epitaxial lamination layer of the light-emitting diode forms a light-emitting area and a peripheral area surrounding the light-emitting area, the light-emitting diode comprises an isolation structure which is formed in the peripheral area and surrounds the light-emitting area, and the isolation structure extends from a light-emitting surface to a second semiconductor layer. The arrangement of the isolation structure enables the light-emitting diode to be obtained through one-time laser cutting, a narrow peripheral area of the light-emitting diode can be achieved, the area of a light-emitting area of an LED chip with the same size is increased, and the light-emitting efficiency of the chip is improved; meanwhile, the isolation structure extends towards the second semiconductor layer of the semiconductor epitaxial lamination layer, so that when the light emitting diode is obtained through laser cutting, electric leakage abnormity caused by the fact that a laser cutting melt-back object is attached to the side wall of the active layer can be avoided, and the reliability of the light emitting diode is improved.

Description

Technical Field

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

[0002] A light-emitting diode (LED) has advantages such as high luminous intensity, high efficiency, small size, and long service life, and is considered to be one of the most potential light sources at present. In recent years, LEDs have been widely used in daily life, such as in the fields of lighting, signal display, backlight, vehicle lamps, and large-screen display. At the same time, these applications also put forward higher requirements for the brightness and luminous efficiency of LEDs.

[0003] In order to obtain an LED with higher brightness, high power, or high heat radiation rate, the conventional LED epitaxial structure is usually transferred to a transfer substrate with a metal reflective layer or a metal bonding layer, and the original substrate is removed by chemical wet etching or laser lift-off. When forming a single chip structure for such a structure, a dicing blade or a laser is usually used for cutting. However, dicing blade cutting has problems such as a relatively wide dicing channel and a large loss of the light-emitting surface, which affects the luminous efficiency, and the cutting may cause chip cracking. Although laser cutting has the advantages of a flat cross-section and a relatively narrow dicing channel, a large amount of metal re-melting material will splash onto the side wall of the light-emitting layer after laser cutting, which is likely to cause leakage of the light-emitting layer.

[0004] It can be seen that the above two cutting methods cannot overcome the defects in terms of luminous efficiency and reliability. Therefore, it is necessary to provide a technical solution that can improve the cutting efficiency while improving the reliability and luminous efficiency of the device. Summary of the Invention

[0005] In view of the defects in terms of luminous efficiency and reliability caused by the cutting of light-emitting devices 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.

[0006] An embodiment of the present application provides a light-emitting diode, which at least includes:

[0007] A semiconductor epitaxial stack including a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence. The side of the first semiconductor layer away from the active layer is the light-emitting surface of the light-emitting diode. The semiconductor epitaxial stack has a light-emitting region and a peripheral region surrounding the light-emitting region;

[0008] An isolation structure located in the peripheral region and forming a closed structure around the light-emitting region. The isolation structure extends from the light-emitting surface to the second semiconductor layer.

[0009] Another embodiment of the present application provides a light-emitting device, which includes a circuit board and a light-emitting element disposed on the circuit board, and the light-emitting element includes the light-emitting diode provided by the present application.

[0010] As described above, the light-emitting diode and the light-emitting device of the present application have the following beneficial effects:

[0011] In the semiconductor epitaxial stack of the light-emitting diode of the present application, a light-emitting region and a peripheral region surrounding the light-emitting region are formed. The light-emitting diode includes an isolation structure formed in the peripheral region and surrounding the light-emitting region, and the isolation structure extends from the light-emitting surface towards the second semiconductor layer. The setting of the isolation structure enables the above-mentioned light-emitting diode to be obtained by one-time laser cutting, and a relatively narrow peripheral region of the light-emitting diode can be achieved. Therefore, for an LED chip of the same size, the area of the light-emitting region is increased, and the light-emitting efficiency of the chip is improved; at the same time, the isolation structure extends towards the second semiconductor layer of the semiconductor epitaxial stack. Therefore, when the light-emitting diode is obtained by laser cutting and separation, abnormal leakage caused by the attachment of laser cutting re-melting substances to the side wall of the active layer can be avoided, and the reliability of the light-emitting diode is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It shows a schematic structural diagram of a light-emitting diode in the prior art.

[0013] Figure 2 It shows a top view structural diagram of the light-emitting device provided in Embodiment 1 of the present invention.

[0014] Figure 3 It shows Figure 2 a schematic cross-sectional structural diagram of the light-emitting device shown along the A-A direction.

[0015] Figure 4 It shows Figure 2 a partial SEM image of the light-emitting device shown.

[0016] Figure 5 It shows Figure 2 a schematic cross-sectional structural diagram of the light-emitting diode obtained by laser cutting in the cutting area of the light-emitting device shown.

[0017] Figure 6 It shows a top view structural diagram of the light-emitting device provided in Embodiment 2 of the present invention.

[0018] Figure 7 It shows Figure 6 a schematic cross-sectional structural diagram of the light-emitting diode obtained after cutting the light-emitting device shown along the A-A direction from the cutting area.

[0019] Figure 8 It shows a top view structural diagram of the light-emitting diode provided in Embodiment 3 of the present invention.

[0020] Figure 9 Shown as Figure 8 Schematic cross-sectional structure diagram along the A-A direction of a light-emitting diode obtained after cutting the shown light-emitting device from the cutting area.

[0021] Figure 10 Shown as a top-view structure diagram of a light-emitting diode provided by an alternative embodiment of Embodiment III.

[0022] Figure 11 Shown as Figure 10 Schematic cross-sectional structure diagram along the A-A direction of a light-emitting diode obtained after cutting the shown light-emitting device from the cutting area.

[0023] Figure 12 Shown as a structure diagram of a light-emitting device provided by Embodiment IV of the present invention.

[0024] Description of component labels

[0025] 10. Light-emitting diode; 11. N-type semiconductor layer; 12. Active layer; 13. P-type semiconductor layer; 14. N electrode;

[0026] 100. Light-emitting device; 101. Light-emitting area; 102. Cutting area; 102'. Peripheral area; 110. Semiconductor epitaxial stack; 111. First semiconductor layer; 112. Active layer; 113. Second semiconductor layer; 120. Dielectric layer; 121. Through hole; 130. Metal reflective layer; 140. Substrate; 151. First electrode; 1511. Pad area, 1512. Extension bar; 152. Second electrode; 153. N-type ohmic contact layer; 160. Insulating reflective layer; 170. Insulating protective layer; 180. Bonding layer; 190. Isolation structure; 191. Groove; 192. Insulating layer;

[0027] 200. Light-emitting device; 201. Circuit board; 202. Light-emitting diode. Detailed implementation manners

[0028] The following uses specific specific examples to illustrate the implementation manners of the present invention. 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 implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0029] As Figure 1 shown, in the prior art, the light-emitting diode 10 after substrate transfer includes an N-type semiconductor layer 11, an active layer 12, and a P-type semiconductor layer 13 stacked in sequence from top to bottom. The side of the N-type semiconductor layer 11 away from the active layer 12 is the light-emitting surface. DivisionFigure 1 When the light-emitting device shown forms a single-chip structure, it is usually cut by a blade or a laser in the cutting area along the direction of the joint R. However, blade cutting has problems such as a relatively wide cutting channel and a large loss of the light-emitting surface, which affects the light-emitting efficiency, and chip cracking caused by cutting; although laser cutting has the advantages of a flat cross-section and a relatively narrow cutting channel, a large amount of metal remelting products will splash onto the side wall of the light-emitting layer after laser cutting, which is likely to cause leakage of the light-emitting layer. In addition, an N electrode 14 is formed on the light-emitting surface, and the N electrode 14 is usually a metal electrode, such as Au, AuGeNi, Ge, Ni, Pt, Pd, etc. This metal electrode has a certain light absorption effect and will absorb the light radiated from the active layer, resulting in a reduction in the light emitted from the light-emitting surface, and also affecting the light-emitting efficiency and brightness of the light-emitting diode.

[0030] In view of the defects in the light-emitting efficiency and reliability of the light-emitting diode in the prior art due to cutting, an embodiment of the present application provides a light-emitting diode, which at least includes:

[0031] A semiconductor epitaxial stack, including a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence, the side of the first semiconductor layer away from the active layer is the light-emitting surface of the light-emitting diode, and the semiconductor epitaxial stack has a light-emitting region and a peripheral region surrounding the light-emitting region;

[0032] An isolation structure, located in the peripheral region and forming a closed structure around the light-emitting region, and the isolation structure extends from the light-emitting surface to the second semiconductor layer.

[0033] The light-emitting diode includes an isolation structure located in the peripheral region and surrounding the light-emitting region, and the isolation structure extends from the light-emitting surface to the second semiconductor layer. The setting of the isolation structure enables the above-mentioned light-emitting diode to be obtained by one-time laser cutting, and a relatively narrow peripheral region of the light-emitting diode can be realized. Therefore, for the same-sized LED chip, the area of the light-emitting region increases, and the light-emitting efficiency of the chip is improved; at the same time, the isolation structure extends to the second semiconductor layer of the semiconductor epitaxial stack. Therefore, when a semiconductor device is cut by a laser, the abnormal leakage caused by the laser cutting remelting products adhering to the side wall of the active layer can be avoided, and the reliability of the chip is improved.

[0034] Optionally, the isolation structure includes a groove extending from the light-emitting surface to the second semiconductor layer, and an insulating layer covering at least the side wall and the bottom of the groove.

[0035] Optionally, the groove extends from the light-emitting surface through the first semiconductor layer and the active layer to the second semiconductor layer, and the bottom of the groove is located in the second semiconductor layer.

[0036] The trench of the isolation structure penetrates the active layer of the semiconductor epitaxial stack, and the sidewalls and bottom of the trench are covered with an insulating layer. Therefore, during laser cutting, the semiconductor epitaxial stack exposed after cutting is insulated from the semiconductor epitaxial stack of the light-emitting region. Therefore, even if the metal reflow falls on the sidewalls of the semiconductor stack after cutting, such as the sidewalls at the active layer, the leakage phenomenon caused by the metal reflow will not occur, improving the reliability of the device.

[0037] Optionally, the depth of the trench in the second semiconductor layer is less than or equal to 1 / 2 of the thickness of the second semiconductor layer.

[0038] The depth of the trench in the second semiconductor layer prevents the semiconductor epitaxial stack from being penetrated, which can ensure the support strength of the semiconductor epitaxial stack and good adhesion to the underlying metal reflective layer, bonding layer, etc., and also ensure good conductivity on one side of the second semiconductor layer.

[0039] Optionally, the insulating layer extends from the sidewalls of the trench to the light-emitting surfaces on both sides of the trench.

[0040] Optionally, the coverage width of the insulating layer on the light-emitting surface is between 1 μm and 5 μm.

[0041] The extension of the insulating layer to the light-emitting surface can increase the adhesion between the insulating layer and the semiconductor stack to a certain extent and increase the reliability of the isolation structure. At the same time, the area of the light-emitting surface covered by the insulating layer is not too large, ensuring a sufficient light-emitting region, which is beneficial to improving the light extraction efficiency.

[0042] Optionally, the distance between the isolation structure and the outer edge of the peripheral region is between 2 μm and 20 μm.

[0043] The above-mentioned small distance between the isolation structure and the outer edge of the peripheral region is beneficial to the arrangement of the isolation structure, making the width of the interval region between two adjacent isolation structures before laser cutting (i.e., the cutting region between two adjacent light-emitting regions in the light-emitting device before cutting) small. For example, the width of the cutting region is 5 μm to 50 μm, further 5 μm to 30 μm, 10 μm to 30 μm. The reduction of the peripheral region can correspondingly increase the area of the light-emitting region, so the light-emitting efficiency of the light-emitting diode can be improved.

[0044] Optionally, the width of the isolation structure is between 5 μm and 20 μm.

[0045] The width of the isolation structure is set to remove as little of the semiconductor epitaxial stack as possible while satisfying its insulation and isolation function, ensuring a sufficient light-emitting region for the device.

[0046] Optionally, the longitudinal cross-section of the isolation structure is triangular, trapezoidal or rectangular.

[0047] The longitudinal cross-section of the groove can be of various shape structures, thus increasing the diversity and applicability of its design. The structure of the above isolation structure can be adjusted according to the specific structure and design requirements of the light-emitting diode chip.

[0048] Optionally, the insulating layer is a single-layer or multi-layer transparent material layer.

[0049] Optionally, the material of the insulating layer is any one or more of SiO2, Si3N4, Al2O3, TiO2, ZnO, HfO2.

[0050] The insulating layer can be any of the above material layers. Specifically, the material can be selected according to the actual design needs of the light-emitting diode.

[0051] Optionally, the light-emitting diode further includes:

[0052] An electrode structure, including a first electrode located on the light-emitting surface and electrically connected to the first semiconductor layer;

[0053] An insulating reflective layer, located at an interval from the light-emitting surface and the first electrode. The insulating reflective layer surrounds the first electrode to form a closed structure, and in the plane of the light-emitting surface, the projection of the first electrode is within the projection range of the insulating reflective layer.

[0054] When the light-emitting diode is energized and emits light, a part of the light emitted from the semiconductor epitaxial stack is in the direction of the first electrode. The above insulating reflective layer is arranged around the first electrode, so that this part of the light can be reflected. A part of the reflected light can be directly emitted, and another part may be reflected back to the semiconductor epitaxial stack and finally emitted from the light-emitting surface after being reflected again. Thereby, the light extraction efficiency of the light-emitting diode is improved and its brightness is increased.

[0055] Optionally, the light-emitting diode further includes:

[0056] An electrode structure, including a first electrode located on the light-emitting surface and electrically connected to the first semiconductor layer;

[0057] The second semiconductor layer includes a P-type current spreading layer, and a concave structure is formed in the P-type current spreading layer. The concave structure extends in the direction towards the first semiconductor layer, and in the plane of the light-emitting surface, the projection of the first electrode is within the projection range of the concave structure.

[0058] The above-mentioned concave structure will increase the resistance of the P-type semiconductor layer surrounded by it. Therefore, the current passing through the active layer corresponding to the first electrode below it is reduced, so that the light emitted by the active layer corresponding to the first electrode below can be reduced, and thus the light incident on the interface of the ohmic contact between the first electrode and the first N-type semiconductor layer is reduced, and the light absorption at the ohmic contact interface is reduced, which can improve the light-emitting efficiency of the light-emitting diode. In addition, the concave structure itself has a certain reflection effect, especially its side wall can reflect part of the light incident thereon, thereby further improving the light extraction efficiency of the light-emitting diode. Correspondingly, the brightness and light-emitting efficiency of the light-emitting device including the light-emitting diode can also be improved accordingly.

[0059] Optionally, the light-emitting diode further includes:

[0060] A dielectric layer formed on the side of the second semiconductor layer away from the active layer, and through holes are formed in the dielectric layer;

[0061] A metal reflection layer formed on the side of the dielectric layer away from the second semiconductor layer and filling the through holes;

[0062] A bonding layer formed on the side of the metal reflection layer away from the dielectric layer;

[0063] A substrate formed on the side of the bonding layer away from the metal reflection layer;

[0064] Projected on the plane where the light-emitting surface is located, the projection of the through hole is located between the projection of the insulating reflection layer and the projection of the isolation structure.

[0065] Alternatively, optionally, projected on the plane where the light-emitting surface is located, the projection of the through hole is located between the projection of the concave structure and the projection of the isolation structure.

[0066] As described above, the light-emitting diode of the present application is preferably a vertical structure. The above-mentioned dielectric layer and metal reflection layer can form a total reflection structure, reflecting the light radiated by the active layer to the side of the light-emitting surface, and cooperating with the insulating reflection layer on the side of the light-emitting surface to increase the light extraction efficiency and brightness of the light-emitting diode.

[0067] Another embodiment of the present invention provides a light-emitting device, which includes the light-emitting diode provided by the present application. Since the light-emitting device includes the light-emitting diode of the present application, good light extraction efficiency and brightness can be achieved.

[0068] Embodiment 1

[0069] This embodiment provides a light-emitting device, such as Figure 2 and Figure 3As shown, the light-emitting device 100 at least includes a semiconductor epitaxial stack 110, which includes a first semiconductor layer 111, an active layer 112, and a second semiconductor layer 113 stacked in sequence. The semiconductor epitaxial stack 110 can be any semiconductor epitaxial stack 110 that can emit light under the action of voltage. In this embodiment, the semiconductor epitaxial stack 110 is preferably an AlGaInP-based epitaxial structure. The first semiconductor layer 111 can be an N-type layer. Correspondingly, the second semiconductor layer 113 is a P-type layer, and vice versa. In this embodiment, the first semiconductor layer 111 is an N-type layer and the second semiconductor layer 113 is a P-type layer as an example.

[0070] In an alternative embodiment, the first semiconductor layer 111 is an N-type AlInP layer for providing electrons. The N-type AlInP layer provides electrons by doping with n-type impurities. The n-type impurities can be, for example, Si, Ge, Sn, Se, and Te, etc. In this embodiment, the n-type impurity is preferably Si, and the Si doping concentration is between 1×10 18 Atoms / cm3 and 2×10 18 Atoms / cm3 to provide electrons for radiative recombination. The second semiconductor layer 113 is a P-type AlInP layer that provides holes by doping with 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. The active layer 112 is a multiple quantum well layer, for example, a multiple quantum well layer formed by AlGaInP / AlInP. Among them, the number of periods of the active layer 112 is 2 to 100, the thickness of the well layer is 2 nm to 25 nm, the thickness of the barrier layer is 2 nm to 25 nm, and the thicknesses of the well layer and the barrier layer can be the same or different, which can be set according to actual needs. The active layer 112 emits light with a wavelength of 550 nm to 950 nm.

[0071] As Figure 2 shown, in this embodiment, the side of the first semiconductor layer 111 away from the active layer 112 is formed as the light-emitting surface of the light-emitting diode 100. The semiconductor epitaxial stack has a plurality of light-emitting regions 101, and the cutting region 102 is between adjacent light-emitting regions. The cutting region is the region for subsequent cutting of the semiconductor epitaxial region to obtain an independent chip structure. In this embodiment, an isolation structure 190 is formed around the light-emitting region 101 (more specifically, between the light-emitting region 101 and the cutting region 102). The isolation structure 190 is formed around each light-emitting region 101 and forms a closed structure surrounding the light-emitting region 101.

[0072] As Figure 3 and Figure 4As shown, the isolation structure 190 extends from the light-emitting surface towards the second semiconductor layer 113. Further, the isolation structure 190 sequentially penetrates through the first semiconductor layer 111 and the active layer 112 from the light-emitting surface and extends to the second semiconductor layer 113. As Figure 3 As shown, the isolation structure 190 includes a trench 191 extending from the light-emitting surface towards the second semiconductor layer 113, and an insulating layer 192 covering at least the sidewalls and the bottom of the trench 191. The trench 191 penetrates through the first semiconductor layer 111 and the active layer 112 from the light-emitting surface and extends to the second semiconductor layer 113, and the bottom of the trench 191 is located in the second semiconductor layer 113. In an alternative embodiment, the depth H0 of the trench 191 in the second semiconductor layer 113 is less than or equal to 1 / 2 of the thickness H6 of the second semiconductor layer 113, that is

[0073] The setting of the isolation structure 190 in this embodiment enables a single chip structure to be obtained by laser cutting a light-emitting device at one time. The trench 191 of the isolation structure 190 penetrates through the active layer 112 of the semiconductor epitaxial stack 110, and the sidewalls and the bottom of the trench 191 are covered with the insulating layer 192. Therefore, during laser cutting, the semiconductor epitaxial stack 110 exposed after cutting is insulated from the semiconductor epitaxial stack 110 of the light-emitting region 102. Therefore, even if the metal reflow falls on the sidewalls of the semiconductor stack 110 after cutting, such as the sidewalls at the active layer 113, no leakage phenomenon caused by the metal reflow will occur, improving the reliability of the device. The depth of the trench 191 in the second semiconductor layer 113 prevents the semiconductor epitaxial stack 110 from being penetrated, which can ensure the support strength of the semiconductor epitaxial stack 110 and good adhesion to the underlying metal reflective layer, bonding layer, etc., and also ensure good electrical conductivity on the side of the second semiconductor layer 113.

[0074] In an alternative embodiment, the spacing distance D0 between adjacent isolation structures 190 of two adjacent light-emitting regions 101 is between 5 μm and 50 μm. Further, D0 is between 10 μm and 30 μm, between 5 μm and 30 μm, between 10 μm and 20 μm, etc. The above insulating layer 192 can also extend from the sidewalls of the trench 191 to the light-emitting surfaces on both sides of the trench 191. Further, the covering width of the insulating layer 192 on the light-emitting surface is between 1 μm and 5 μm. Further, it is between 1 μm and 3 μm. The width W0 of the isolation structure 190 is between 5 μm and 20 μm. Further, W0 is between 5 μm and 10 μm, between 10 μm and 15 μm, etc. The longitudinal cross-section of the isolation structure 190 is triangular, trapezoidal, rectangular, etc. Further, the longitudinal cross-section of the trench 191 of the above isolation structure 190 is triangular, trapezoidal, rectangular, etc., that is, the longitudinal cross-section of the trench 191 can be any structure that can be obtained by etching the semiconductor epitaxial stack 110.

[0075] The interval region between two adjacent isolation structures 190 is the cutting region 102 between two adjacent light-emitting regions 101. The arrangement of the isolation structures 190 enables the width of the cutting region 102 to be further reduced. The reduction of the cutting region 102 can correspondingly increase the area of the light-emitting region 101, thereby improving the light-emitting efficiency of the device. The width of the isolation structure 190 is set to remove as little semiconductor epitaxial stack as possible while fulfilling its insulation and isolation function, ensuring a sufficient light-emitting region 101 for the device. The longitudinal cross-section of the trench 191 can be of various shape structures, thus increasing the diversity and applicability of its design. The structure of the above isolation structure 190 can be adjusted according to the specific structure and design requirements of the light-emitting diode chip. The insulating layer 192 extends to the light-emitting surface, which can increase the adhesion between the insulating layer 192 and the semiconductor epitaxial stack 110 to a certain extent and enhance the reliability of the isolation structure 190. At the same time, the area of the light-emitting surface covered by the insulating layer 192 is not too large, ensuring a sufficient light-emitting region and being conducive to improving the light extraction efficiency.

[0076] In an alternative embodiment, the insulating layer 192 is a single-layer or multi-layer transparent material layer. Further, the material of the insulating layer 192 is any one or more of SiO2, Si3N4, Al2O3, TiO2, ZnO, HfO2. The insulating layer 192 can be any of the above material layers. Specifically, the material can be selected according to the actual design requirements of the light-emitting device.

[0077] Refer again to Figure 3 , the light-emitting diode 100 of this embodiment further includes a substrate 140 and an electrode structure. The semiconductor epitaxial stack 110 is bonded to the substrate 140 from one side of the second semiconductor layer 113. A bonding layer 180 is formed between the semiconductor epitaxial stack 110 and the substrate 140, and the bonding layer 180 bonds the semiconductor epitaxial stack 110 and the substrate 140 together. The above electrode structure includes a first electrode 151 formed on the light-emitting surface and electrically connected to the first semiconductor layer 111 and a second electrode 152 located on the side of the substrate away from the semiconductor epitaxial stack 110 and electrically connected to the second semiconductor layer 113. Optionally, an N-type ohmic contact layer 153 is provided between the first electrode 151 and the first semiconductor layer 111. Further, as Figure 2 and Figure 3 shown, the above first electrode 151 has a pad region 1511 and an extension bar 1512. The extension bar 1512 extends from the pad region 1511 to other regions of the light-emitting surface to improve the current diffusion effect and uniformity on the side of the first semiconductor layer 111. In an alternative embodiment, the above extension bar 1512 is formed as a finger-shaped extension bar 1512, and the first electrode 151 can include one or more of the above extension bars 1512.

[0078] The above-mentioned substrate 140 may be an insulating substrate, a semiconductor substrate, a metal substrate, etc. In this embodiment, the substrate 110 is a silicon (Si) substrate, a germanium (Ge) substrate, a silicon carbide (SiC) substrate, a gallium nitride (GaN) substrate, an aluminum nitride (AlN) substrate, a gallium phosphide (GaP) substrate, or a gallium arsenide (GaAs) substrate, etc. Optionally, the bonding layer 180 is a metal bonding layer, such as Cu, Al, Sn, Au, Ag, Pb, Ti, Ni, In, Pt or W, etc. A dielectric layer 120 and a metal reflective layer 130 are further formed between the bonding layer 180 and the semiconductor epitaxial stack 110, and the metal reflective layer 130 is formed between the dielectric layer 120 and the bonding layer 180. Specifically, the dielectric layer 120 is formed on the side of the second semiconductor layer 113 away from the active layer 112, the metal reflective layer 130 is formed on the side of the dielectric layer 120 away from the second semiconductor layer 113, and the bonding layer 180 covers the metal reflective layer 130. In an alternative embodiment, a through hole 121 is formed in the dielectric layer 120, and the metal reflective layer 130 fills the through hole 121, so as to realize electrical connection with the second semiconductor layer 113.

[0079] The dielectric layer 120 may be a single-layer structure formed of one of SiO2, SiN, SiON, TiO2, etc., or a multi-layer structure formed by any combination of them. Optionally, it is a DBR structure with a reflective effect, such as a DBR structure formed of SiO2 and TiO2. Optionally, the metal reflective layer may be an alloy of one or more of Ag, Al, Cu, Sn, Au, etc. In this embodiment, the dielectric layer 120 is a DBR structure, the metal reflective layer 130 is an Ag mirror, and the dielectric layer 120 and the metal reflective layer 130 form a total reflection structure. The reflection of the light radiated by the active layer 112 is increased, and the light extraction efficiency of the light emitting diode 100 is enhanced. In addition, as described above, both the metal reflective layer 130 and the bonding layer 180 are metal layers, so the adhesion between them is good, which is beneficial to improving the reliability of the light emitting diode. On the other side of the substrate 140 opposite to the semiconductor epitaxial stack 110, a back gold layer is formed, and this back gold layer can be used as the second electrode 152 for electrical connection with the second semiconductor layer 113.

[0080] Referring to Figure 3 , in order to further increase the light extraction efficiency of the light emitting diode 100, in this embodiment, after the first electrode 151 is formed, the light emitting surface of the region outside the region covered by the first electrode 151 is roughened to form a roughened surface, thereby increasing the light extraction rate.

[0081] This embodiment also provides a light emitting diode. By using a laser cutting method, in Figure 2The shown cutting region 102 cuts the semiconductor epitaxial stack 110, dielectric layer 120, metal reflection layer 130, bonding layer 180, substrate 140, and back gold layer (second electrode 152) sequentially from the light-emitting surface downward to obtain the light-emitting diode. Specifically, as Figure 5 shown, the light-emitting diode includes a light-emitting region 101, a peripheral region 102' surrounding the light-emitting region, and an isolation structure 190 located in the peripheral region 102'. The peripheral region 102' is the remaining cutting region after laser cutting the above-mentioned cutting region 102. The distance D0' between the isolation structure 190 and the outer edge of the peripheral region 102' is between 2 μm and 20 μm, and further, between 2 μm and 10 μm, 5 μm and 15 μm, etc. Similarly referring to Figure 5 , an insulating protective layer 170 is also formed on the exposed sidewall of the light-emitting diode to protect the light-emitting diode from damage by external moisture and impurities and improve the reliability of the light-emitting diode.

[0082] Embodiment 2

[0083] This embodiment also provides a light-emitting device. As Figure 6 shown, the light-emitting device 100 also at least includes a semiconductor epitaxial stack 110 and an isolation structure extending from the light-emitting surface of the light-emitting device to the second semiconductor layer 113. The same parts as those in Embodiment 1 will not be described again. The differences are as follows:

[0084] As Figure 6 shown, the light-emitting device 100 of this embodiment is also provided with an insulating reflection layer 160 on the light-emitting surface. The insulating reflection layer 160 is arranged at an interval from the first electrode 151 and surrounds the first electrode 151. That is, the insulating reflection layer 160 has the same contour as the first electrode 151 and forms a closed figure around the first electrode 151. In an alternative embodiment, the shape of the longitudinal section of the above-mentioned insulating reflection layer 160 can be any suitable shape, such as a rectangle, triangle, trapezoid, etc., which is easy to operate and can make the insulating reflection layer 160 have a good reflection effect.

[0085] Specifically, projected on the plane where the light-emitting surface is located, that is, in the Figure 6 top view direction, the projection of the first electrode 151 completely falls within the projection range of the insulating reflection layer 160. As Figure 6 shown, the insulating reflection layer 160 forms a closed figure along the contours of the pad region 1511 and the extension strip 1512 of the first electrode 151, so that the pad region 1511 and the extension strip 1512 of the first electrode 151 are both surrounded by the insulating reflection layer 160.

[0086] This embodiment also provides a light-emitting diode, which also uses the method of laser cutting inFigure 6 The shown cutting area 102 is obtained by cutting the semiconductor epitaxial stack 110, dielectric layer 120, metal reflective layer 130, bonding layer 180, substrate 140 and back gold layer (second electrode 152) successively downward from the light-emitting surface. As Figure 7 shown, a schematic diagram of the light-emitting diode of this embodiment is shown. Among them, the width of the insulating reflective layer 160 satisfies: 1μm ≤ W2 ≤ 5μm, for example, W = 2μm; W2 = 3μm; W2 = 5μm, etc. The width of the insulating reflective layer 160 is defined so that it does not cover too much of the light-emitting surface, avoiding the loss of the light-emitting surface caused by excessive coverage and affecting the light-emitting efficiency. Similarly, as Figure 7 shown, the height H2 of the insulating reflective layer 160 protruding on the light-emitting surface is not higher than the height H1 of the first electrode 151, that is, the height H2 of the insulating reflective layer 160 is less than or equal to the height H1 of the first electrode 151. Further, the height H1 of the above-mentioned first electrode 151 satisfies: 2μm ≤ H1 ≤ 5μm, and the height H2 of the insulating reflective layer 160 satisfies: 1μm ≤ H2 ≤ 5μm. In addition, the spacing distance D2 between the first electrode 151 and the insulating reflective layer 160 satisfies: 1μm ≤ D2 ≤ 10μm, for example, D2 = 2μm; D2 = 5μm; D2 = 7μm; D2 = 10μm, etc. The definition of the height of the insulating reflective layer 160 and the first electrode 151 and the spacing distance therebetween can ensure that the insulating reflective layer 160 has a good reflection effect on the incident light, and at the same time ensure that the insulating reflective layer 160 will not affect the subsequent wire bonding and other processes of the first electrode 151, especially the pad area 1511, and ensure the reliability of the light-emitting diode.

[0087] Optionally, the above-mentioned insulating reflective layer 160 can be a single-layer structure or a multi-layer structure. Further, the insulating reflective layer 160 is a transparent material layer, for example, it can be any one or a combination of materials with high reflectivity and high transparency such as SiO2, Si3N4, Al2O3, TiO2, ZnO, HfO2, etc. Further, the above-mentioned insulating reflective layer 160 can be formed into a DBR structure with a total reflection effect, for example, a DBR structure formed by SiO2 and TiO2. The material selection of the insulating reflective layer 160 can be carried out according to the actual design requirements of the light-emitting diode 100 to increase its scope of application.

[0088] In an alternative embodiment, the vias 121 in the dielectric layer 120 are distributed in a region outside the region corresponding to the enclosed structure formed by the insulating reflective layer 160. That is, when projected onto the plane where the light-emitting surface is located, the projection of the via 121 is located outside the projection range of the insulating reflective layer 160, and within the projection range of the insulating reflective layer 160, it is covered by the dielectric layer 120. Thus, the accumulation of current in the region corresponding to the first electrode 151 can be prevented, the current uniformity of the light-emitting diode can be improved, and its light-emitting efficiency can be further enhanced.

[0089] Referring again to Figure 7 , in this embodiment, after forming the first electrode 151 and the insulating reflective layer 160, the surface of the first semiconductor layer 111 in the region outside the region surrounded by the insulating reflective layer 160, that is, the region covered by the first electrode 151 and the insulating reflective layer 160 and the region between the first electrode 151 and the insulating reflective layer 160, is roughened to form a roughened surface, thereby increasing the light extraction rate.

[0090] Embodiment III

[0091] This embodiment also provides a light-emitting diode. As Figure 8 shown, the light-emitting diode 100 also includes at least a semiconductor epitaxial stack 110 and an isolation structure extending from the light-emitting surface of the light-emitting diode towards the second semiconductor layer 113. The same parts as those in Embodiment I will not be described again. The differences are as follows:

[0092] Reference can be made to Figure 9As shown, the above-mentioned P-type semiconductor layer includes a P-type confinement layer 1131 and a P-type current spreading layer 1132. The P-type confinement layer 1131 can be a P-type AlInP carrier confinement layer, which is used to prevent holes and electrons from escaping from the active layer 112 to the P-type semiconductor layer or the N-type semiconductor layer, ensuring efficient recombination and light emission of electrons and holes within the active layer 112. The P-type current spreading layer 1132 can be a P-type AlGaInP layer, a GaP layer, etc. In this embodiment, the P-type current spreading layer is preferably a P-type GaP layer. The P-type current spreading layer 1132 can reduce resistance and make the current evenly distributed throughout the P-type semiconductor layer instead of being concentrated near the electrode. In this embodiment, the P-type current spreading layer 1132 is formed with a recessed structure 1130. The recessed structure 1130 extends in the direction towards the N-type semiconductor layer, and at the same time, the recessed structure 1130 does not extend to the interface between the P-type semiconductor layer and the active layer, that is, the bottom of the recessed structure 1130 is located within the P-type current spreading layer 1132; alternatively, the recessed structure 1130 penetrates through the P-type current spreading layer 1132 to its bottom located within the P-type confinement layer 1131 and is lower than the interface between the P-type semiconductor layer and the active layer 112. The above setting of the recessed structure 1130 can reduce non-radiative recombination caused by sidewall defects of the active layer 112 and improve the light emission efficiency of the chip. In an alternative embodiment, the shape of the longitudinal cross-section of the above-mentioned recessed structure 1130 can be any suitable shape, such as a rectangle, a triangle, a trapezoid, etc.

[0093] As Figure 8 shown, when projected onto the plane where the light-emitting surface is located, the projection of the first electrode 151 is within the projection range of the recessed structure 1130. That is, the recessed structure 1130 forms a closed figure along the contours of the pad region 1511 and the extension bar 1512 of the first electrode 151 on the periphery of the pad region 1511 and the extension bar 1512 of the first electrode 151, such that the projections of the pad region 1511 and the extension bar 1512 of the first electrode 151 are both surrounded by the projection of the recessed structure 1130. The above setting of the recessed structure 1130 increases the resistance of the P-type semiconductor layer 113 surrounded by it, reduces the current passing through the corresponding active layer 112 under the first electrode 151, thereby reducing the light emitted by the corresponding active layer 112 under the first electrode 151, reducing the light that can be incident on the interface of the ohmic contact between the first electrode 151 and the N-type semiconductor layer, reducing the light absorption at the ohmic contact interface, and improving the light emission efficiency of the light-emitting diode. In addition, the recessed structure 1130 itself has a certain reflection effect, especially its sidewalls can reflect part of the incident light, thereby further improving the light extraction efficiency of the light-emitting diode.

[0094] This embodiment also provides a light-emitting diode. The light-emitting diode also uses a laser cutting method in Figure 8The cutting region 102 shown is obtained by cutting the semiconductor epitaxial stack 110, the dielectric layer 120, the metal reflective layer 130, the bonding layer 180, the substrate 140, and the back gold layer (the second electrode 152) in sequence from the light-emitting surface downward. Combining Figure 9 , the through holes 121 in the dielectric layer 120 are distributed between the recessed structure 1130 and the isolation structure 190. That is, in the projection on the plane where the light-emitting surface is located, the projection of the above through holes 121 is located in the region between the projection of the recessed structure 1130 and the projection of the isolation structure 190. As Figure 9 shown, a schematic diagram of the light-emitting diode of this embodiment is shown. Among them, the width W1 of the recessed structure 1130 satisfies: 3μm ≤ W1 ≤ 15μm, for example, W1 = 2μm; W1 = 3μm; W1 = 5μm, etc. In addition, as Figure 8 shown, in the projection on the plane where the light-emitting surface is located, the recessed structure 1130 and the first electrode 151 are arranged at intervals, and the interval distance D1 between the recessed structure 1130 and the first electrode 151 satisfies: 3μm ≤ D1 ≤ 15μm, for example, D1 = 3μm; D1 = 5μm; D1 = 7μm; D1 = 10μm, D1 = 15μm, etc. The width limitation of the recessed structure 1130 enables a certain thickness of the P-type semiconductor layer to remain around it, thereby increasing the contact area between the semiconductor epitaxial stack 110 and the bonding layer 180 and improving the reliability of the light-emitting diode, especially improving the wire bonding resistance of the light-emitting diode.

[0095] Optionally, combining Figure 9 , the recessed structure 1130 does not extend to the interface between the P-type semiconductor layer and the active layer 112, that is, the recessed structure 1130 is located in the P-type current spreading layer 1132; or, the recessed structure 1130 penetrates through the P-type current spreading layer 1132 to its bottom located in the P-type confinement layer 1131 and is lower than the interface between the P-type semiconductor layer and the active layer 112. That is, the recessed depth H3 of the above recessed structure 1130 is less than or equal to the thickness H5 of the P-type current spreading layer 1132: H3 ≤ H5; or the recessed depth H3 of the above recessed structure 1130, the thickness H5 of the P-type current spreading layer 1132, and the thickness H4 of the P-type confinement layer 1131 satisfy: H5 ≤ H3 ≤ H4. For example, in an alternative embodiment, the thickness H4 of the above P-type confinement layer 1131 ranges from 400nm to 600nm, the thickness of the P-type current spreading layer 1132 ranges from 2000nm to 3000nm, and the recessed height H3 of the recessed structure 1130 ranges from 2500nm to 3500nm. The bottom of the recessed structure 1130 is located in the P-type current spreading layer 1132 or in the P-type confinement layer 1131 and does not extend to the interface between the active layer 112 and the P-type layer, thereby reducing the non-radiative recombination caused by the sidewall defects of the active layer 112 and improving the light-emitting efficiency of the chip.

[0096] In an alternative embodiment of the present embodiment, as Figure 10 shown, an insulating reflective layer 160 is formed on the light-emitting surface of the light-emitting device and is spaced apart from the first electrode 151. The insulating reflective layer 160 is spaced apart from the first electrode 151 and is disposed around the first electrode 151. That is, the insulating reflective layer 160 has the same contour as the first electrode 151 and forms a closed figure around the first electrode 151. Projected onto the plane of the light-emitting surface, that is, in the Figure 10 shown top-down direction, the projection of the first electrode 151 completely falls within the projection range of the insulating reflective layer 160. Further, as also Figure 10 shown, the projection of the above-mentioned insulating reflective layer 160 completely falls within the projection range of the recessed structure 1130. Other settings of the insulating reflective layer 160 can refer to the specific description of Embodiment 2 and will not be elaborated here again. The above-mentioned insulating reflective layer 160 and the recessed structure 1130 can cooperate to further improve the light extraction efficiency of the device. In an alternative embodiment, along the Figure 10 shown cutting region 102, the semiconductor epitaxial stack 110, the dielectric layer 120, the metal reflective layer 130, the bonding layer 180, the substrate 140, and the back gold layer (second electrode 152) are sequentially cut downward from the light-emitting surface to obtain a separate light-emitting diode. As Figure 11 shown, the light-emitting diode also has the above-mentioned structural settings, and an insulating protective layer 170 is formed on the side wall of the light-emitting diode to improve the reliability of the light-emitting diode.

[0097] Embodiment 4

[0098] The present embodiment provides a light-emitting device. As Figure 12 shown, the light-emitting device 200 includes a circuit board 201 and at least one light-emitting diode 202 fixed to the circuit board 201. The light-emitting diode includes the light-emitting diode provided in Embodiment 4 of the present application. Since the light-emitting device includes any one or more of the light-emitting diodes provided in Embodiments 1 to 3, it has good light extraction efficiency and better reliability.

[0099] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A light-emitting diode, characterized in that, Comprising at least: A semiconductor epitaxial stack including a first semiconductor layer, an active layer, and a second semiconductor layer stacked in sequence. The side of the first semiconductor layer away from the active layer is the light-emitting surface of the light-emitting diode. The semiconductor epitaxial stack has a light-emitting region and a peripheral region surrounding the light-emitting region. An isolation structure located in the peripheral region and forming a closed structure around the light-emitting region. The isolation structure extends from the light-emitting surface towards the second semiconductor layer.

2. The light-emitting diode according to claim 1, wherein The isolation structure includes a trench extending from the light-emitting surface towards the second semiconductor layer, and an insulating layer covering at least the sidewall and bottom of the trench.

3. The light-emitting diode according to claim 2, characterized in that, The trench extends from the light-emitting surface through the first semiconductor layer and the active layer to the second semiconductor layer, and the bottom of the trench is located in the second semiconductor layer.

4. The light-emitting diode according to claim 3, wherein The depth of the trench in the second semiconductor layer is less than or equal to 1 / 2 of the thickness of the second semiconductor layer.

5. The light-emitting diode according to claim 2, wherein The insulating layer extends from the sidewall of the trench to the light-emitting surfaces on both sides of the trench.

6. The light-emitting diode according to claim 5, characterized in that, The covering width of the insulating layer on the light-emitting surface is between 1 μm and 5 μm.

7. The light emitting diode according to claim 1, characterized in that, The distance between the isolation structure and the outer edge of the peripheral region is between 2 μm and 20 μm.

8. The light emitting diode according to claim 1, wherein The width of the isolation structure is between 5 μm and 20 μm.

9. The light-emitting diode according to claim 1, wherein, The longitudinal cross-section of the isolation structure is triangular, trapezoidal, or rectangular.

10. The light emitting diode according to claim 2, characterized in that, The insulating layer is a single-layer or multi-layer transparent material layer.

11. The light-emitting diode according to claim 10, wherein, The material of the insulating layer is any one or more of SiO2, Si3N4, Al2O3, TiO2, ZnO, HfO2.

12. The light-emitting diode according to claim 1, characterized in that, The light-emitting diode further includes: An electrode structure including a first electrode located on the light-emitting surface and electrically connected to the first semiconductor layer. An insulating reflective layer spaced from the first electrode on the light-emitting surface. The insulating reflective layer is disposed around the first electrode to form a closed structure, and in the projection on the plane of the light-emitting surface, the projection of the first electrode is within the projection range of the insulating reflective layer.

13. The light-emitting diode according to claim 1, characterized in that, The light-emitting diode further includes: An electrode structure including a first electrode located on the light-emitting surface and electrically connected to the first semiconductor layer. The second semiconductor layer includes a P-type current spreading layer, and a recessed structure is formed in the P-type current spreading layer and extends in the direction towards the first semiconductor layer. In the projection on the plane of the light-emitting surface, the projection of the first electrode is within the projection range of the recessed structure.

14. The light-emitting diode according to claim 12, wherein, Further including: A dielectric layer formed on the side of the second semiconductor layer away from the active layer, and a through hole is formed in the dielectric layer. A metal reflective layer formed on the side of the dielectric layer away from the second semiconductor layer and filling the through hole. A bonding layer formed on the side of the metal reflective layer away from the dielectric layer. A substrate formed on the side of the bonding layer away from the metal reflective layer. In the projection on the plane of the light-emitting surface, the projection of the through hole is between the projection of the insulating reflective layer and the projection of the isolation structure.

15. The light-emitting diode according to claim 13, characterized in that, Further including: A dielectric layer formed on the side of the second semiconductor layer away from the active layer, and a through hole is formed in the dielectric layer. A metal reflective layer, formed on a side of the dielectric layer away from the second semiconductor layer and filling the through hole; A bonding layer, formed on a side of the metal reflective layer away from the dielectric layer; A substrate, formed on a side of the bonding layer away from the metal reflective layer; When projected onto the plane where the light emitting surface is located, the projection of the through hole is located between the projection of the recessed structure and the projection of the isolation structure.

16. A light-emitting device, characterized in that, It includes a circuit board and a light emitting element disposed on the circuit board, and the light emitting element includes the light emitting diode according to any one of claims 1 to 15.

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