Light emitting element and method for manufacturing the same

Abstract

The present application provides a light emitting element and a manufacturing method thereof. The light emitting element comprises an epitaxial layer, a first electrode, a groove, a second electrode and a heat dissipation metal. The epitaxial layer has a current confinement region and an active layer. The first electrode is disposed on the epitaxial layer and has a light emitting hole. The groove is disposed on an opposite side of the epitaxial layer opposite to the light emitting hole. The second electrode covers a surface of the groove. The heat dissipation metal covers the groove. When a current flows through the first electrode, the current confinement region and the active layer, the active layer excites a light which is emitted out of the epitaxial layer through the current confinement region and the light emitting hole. The heat energy generated by the active layer in the current confinement region is dissipated through the heat dissipation metal in the groove.

Description

Technical Field

[0001] This invention relates to a light-emitting element and a method for manufacturing the same, and more particularly to a light-emitting element with a high thermal conductivity structure and a method for manufacturing the same. Background Technology

[0002] In order to excite the laser, a vertical cavity surface-emitting laser (VCSEL) device confines the current to a small area with an oxide layer, called the oxide aperture (OA), to form a high-density current and achieve a small threshold current.

[0003] Because the current can be confined within a small area of ​​the active light-emitting layer by the oxide layer, its heat dissipation model will approximate a point heat source, and its heat flow diffusion will be approximately a cosine function distribution. The power density is inversely proportional to the distance from the heat source. Due to the high local current density and rising temperature in the active light-emitting layer, the band gap is distorted, resulting in a roll-over relationship between current and power. This causes a decrease in power output efficiency at high current, and may even lead to problems such as the inability to emit laser light at high temperatures and high currents.

[0004] Because the back electrode of a traditional VCSEL device is a flat heat dissipation structure, the distance between it and the light-emitting active layer that generates heat is large, making heat dissipation difficult. Moreover, unlike other devices, the heat dissipation model for traditional VCSEL devices is independent of the device size; increasing the device size does not improve heat dissipation efficiency. Therefore, how to effectively improve the heat dissipation efficiency of VCSEL devices and prevent burnout in the OA region due to poor heat dissipation is an urgent problem to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a light-emitting element and its manufacturing method. Based on the light-emitting element proposed by the applicant in Taiwan Patent No. I878998, the thermal conductivity structure is optimized to provide a three-dimensional heat dissipation path, thereby breaking through the limitations of the original heat dissipation model which is like a cosine function of a point heat source, shortening the heat dissipation path, and achieving the goal of improving the heat dissipation efficiency and reliability of VCSEL elements.

[0006] To achieve the above objectives, this invention discloses a light-emitting element comprising an epitaxial layer, a first electrode, a trench, a second electrode, and a heat-dissipating metal. The epitaxial layer has a current-limiting region and an active layer. The first electrode is disposed on the epitaxial layer and has a light-emitting aperture. The trench is disposed on an opposite side of the epitaxial layer to the light-emitting aperture. The second electrode covers a surface of the trench, and the heat-dissipating metal covers the trench. When a current flows through the first electrode and the current-limiting region into the active layer, the active layer excites light to pass through the current-limiting region and the light-emitting aperture, exiting the epitaxial layer. Furthermore, the heat generated in the active layer within the current-limiting region is dissipated to the outside via the heat-dissipating metal within the trench.

[0007] In one embodiment of the present invention, the light-emitting element has a groove that penetrates the active layer.

[0008] In one embodiment of the present invention, the light-emitting element has an annular groove, such that the heat-dissipating metal covering the annular groove surrounds the current-limiting region and the active layer.

[0009] In one embodiment of the present invention, the heat dissipation metal of the light-emitting element is either a tin-gold (AuSn) alloy or gold (Au).

[0010] In one embodiment of the present invention, the epitaxial layer of the light-emitting element further has a trench that penetrates the epitaxial layer and longitudinally divides the epitaxial layer into a first region and a second region that are separate from each other.

[0011] In one embodiment of the present invention, the light-emitting element has a groove disposed in a first region of the epitaxial layer, and a second region of the epitaxial layer has a longitudinal through hole.

[0012] In one embodiment of the present invention, the light-emitting element further includes a first metal pad and a second metal pad, wherein the first metal pad is disposed in the second region and extends longitudinally along the longitudinal through hole to be electrically connected to the first electrode, and the second metal pad is disposed in the first region and is electrically connected to the second electrode.

[0013] To achieve the above objectives, this invention discloses a method for manufacturing a light-emitting element, comprising: providing an epitaxial layer having an active layer; providing a first electrode disposed on the epitaxial layer, the first electrode having a light-emitting aperture; providing a trench disposed on a side of the epitaxial layer opposite to the light-emitting aperture; then, oxidizing the trench with moisture to form a current-confined region on the active layer; providing a second electrode covering a surface of the trench; and finally, providing a heat-dissipating metal covering the trench, wherein when a current flows into the active layer through the first electrode and the current-confined region, the active layer will excite a light source to pass through the current-confined region and the light-emitting aperture and then exit the epitaxial layer, and the heat generated by the active layer in the current-confined region can be dissipated to the outside through the heat-dissipating metal in the trench.

[0014] In one embodiment of the present invention, the method for manufacturing a light-emitting element includes providing an annular groove that penetrates the active layer, such that heat-dissipating metal covers the annular groove to surround the current-limiting region and the active layer.

[0015] In one embodiment of the present invention, the step of moisture oxidation of the annular groove in the manufacturing method of the light-emitting element is to form a current blocking layer on the active layer, wherein the current blocking layer has an oxide pore size for use as a current confinement region.

[0016] In one embodiment of the present invention, the method for manufacturing a light-emitting element has an oxide pore size of 5 to 20 micrometers (μm).

[0017] In one embodiment of the present invention, the step of providing a heat-dissipating metal in the manufacturing method of a light-emitting element is to provide either a tin-gold (AuSn) alloy or gold (Au).

[0018] In one embodiment of the present invention, the method for manufacturing a light-emitting element further includes a step of providing a trench through the epitaxial layer to longitudinally divide the epitaxial layer into a first region and a second region that are separate from each other, wherein the second region has a longitudinal through hole.

[0019] In one embodiment of the present invention, the method for manufacturing a light-emitting element further includes a step of providing a first metal pad and a second metal pad, wherein the first metal pad is disposed in a second region and extends longitudinally along a longitudinal through hole to be electrically connected to a first electrode, and the second metal pad is disposed in a first region and electrically connected to a second electrode.

[0020] Other objects of the present invention, as well as the technical means and implementation methods of the present invention, will be understood by those skilled in the art upon referring to the accompanying drawings and the embodiments described below. Attached Figure Description

[0021] Figure 1 This shows a cross-sectional schematic diagram of a light-emitting element in one embodiment of the present invention;

[0022] Figure 2A This diagram shows a heat dissipation path of the light-emitting element in one embodiment of the present invention;

[0023] Figure 2B A partially enlarged schematic diagram showing the three-dimensional heat dissipation structure;

[0024] Figures 3 to 16 This diagram shows a method for manufacturing a light-emitting element according to an embodiment of the present invention;

[0025] Figure 17 This diagram illustrates the encapsulation application of a light-emitting element in one embodiment of the present invention;

[0026] Figure 18 This diagram shows a packaging application of the light-emitting element in another embodiment of the present invention;

[0027] Figure 19 A schematic diagram showing the packaging application of the light-emitting element in another embodiment of the present invention; and

[0028] Figure 20 This diagram shows a process flow chart of the light-emitting element in one embodiment of the present invention.

[0029] Explanation of reference numerals in the attached figures

[0030] 1. Light-emitting element

[0031] 2. Hot Abyss

[0032] 10 substrate

[0033] 11 Epitaxial Layer

[0034] 11a N-type epitaxial layer

[0035] 11b Active Layer

[0036] 11c P-type epitaxial layer

[0037] 11d Current barrier layer

[0038] 11e Oxidation Pore Size

[0039] 12 Insulation layer

[0040] 13 First Electrode

[0041] 13a light hole

[0042] 14 BCB Layer

[0043] 15 Insulation layer

[0044] 16. Grooves

[0045] 17. Trench

[0046] 18 longitudinal through holes

[0047] 19 Insulation layer

[0048] 20 Second electrode

[0049] 21 First metal pad

[0050] 22 Second metal pad

[0051] 23 Heat dissipation metal

[0052] 100 Epitaxial Growth Substrate

[0053] R1 First Area

[0054] R2 Second Region. Detailed Implementation

[0055] The following embodiments will explain the content of this invention. These embodiments are not intended to limit the implementation of this invention to any specific environment, application, or special method described in the embodiments. Therefore, the descriptions of the embodiments are merely illustrative of the invention and not intended to limit it. It should be noted that in the following embodiments and accompanying drawings, elements not directly related to this invention have been omitted and are not shown, and the dimensional relationships between the elements in the drawings are for ease of understanding only and are not intended to limit the actual scale.

[0056] This invention relates to a light-emitting element, and more particularly to a VCSEL element and its manufacturing method. This invention provides a three-dimensional heat dissipation path to overcome the limitations of the point-source cosine function-like heat dissipation model in VCSEL elements, shortening the heat dissipation path and improving the heat dissipation efficiency and reliability of the VCSEL element, as detailed below.

[0057] Please see Figure 1 The diagram shows a cross-sectional view of the light-emitting element 1 in one embodiment of the present invention, which has a flip-chip structure, that is, the light-emitting element 1 is a vertical-cavity surface-emitting laser (VCSEL) flip chip. It should be noted that this flip-chip configuration is only one embodiment of the present invention, and the present invention can also be applied to other laser chips that also have point-like heat sources, such as vertically oriented laser chips. Figure 1 As shown, the light-emitting element 1 of the present invention includes a substrate 10, an epitaxial layer 11, a first electrode 13, a second electrode 20, and a heat-dissipating metal 23. The substrate 10 may be a sapphire (Al2O3) substrate, but is not limited thereto. Depending on the application, any transparent substrate with a light transmittance exceeding 90% can be used.

[0058] The epitaxial layer 11 can be formed by alternating stacks of gallium arsenide (GaAs), aluminum gallium arsenide (AlxGa(1-x)As), and aluminum arsenide (AlAs), and the bandgap of the epitaxial layer 11 can be between 1.3 and 2.5 eV. In the VCSEL device, the epitaxial layer 11 includes an N-type epitaxial layer 11a, an active layer 11b, and a P-type epitaxial layer 11c, wherein the active layer 11b is a multiple quantum well disposed on the N-type epitaxial layer 11a, and the P-type epitaxial layer 11c is disposed on the active layer 11b. The N-type epitaxial layer 11a and the P-type epitaxial layer 11c can each be a stack of mirrors, such as a distributed Bragg reflector (DBR).

[0059] Furthermore, such as Figure 1As shown, the epitaxial layer 11 also includes two current-blocking layers 11d, which are disposed slightly above the active layer 11b in the P-type epitaxial layer 11c and laterally separated by a distance to form an oxide aperture (OA) 11e. Each current-blocking layer 11d is an insulating layer, which can be formed by moisture oxidation or ion implantation. The radius of the oxide aperture 11e formed by the current-blocking layer 11d is approximately 5–20 micrometers (μm), serving as both a current-confined region and an optical-confined region. This allows the VCSEL device to effectively concentrate the current through the oxide aperture 11e during operation, reducing lateral current diffusion and confining light to the central region for focused propagation, thus optimizing the optical distribution and improving beam quality and luminous efficiency.

[0060] Please continue reading. Figure 1 The epitaxial layer 11 of the light-emitting element 1 of the present invention also has a trench 17, which longitudinally divides the epitaxial layer 11 into a first region R1 and a second region R2. In this way, the first region R1 and the second region R2 can be separated from each other. In actual manufacturing, the trench 17 can be formed by a wet etching process or a dry etching process. The trench 17 may be left unfilled or filled with an elastic material, as long as it can withstand stress and prevent the epitaxial layer from breaking.

[0061] The first electrode 13 is disposed on the upper surface of the P-type epitaxial layer 11c of the epitaxial layer 11 and is electrically connected to the P-type epitaxial layer 11c of the first region R1 of the epitaxial layer 11 through appropriate wiring arrangement. Specifically, the first electrode 13 includes a light-emitting aperture 13a in the first region R1. The light-emitting aperture 13a has a radius of approximately 5-10 micrometers (μm), preferably 8 micrometers (μm), and this light-emitting aperture 13a corresponds vertically to the oxide aperture 11e of the current-limited region in the first region R1, allowing light generated by the active layer 11b to be radiated vertically outward through the oxide aperture 11e and the aperture 13a. The first electrode 13 is made of a metallic material selected from one or a combination of silver (Ag), titanium (Ti), platinum (Pt), germanium (GeAu), and gold (Au). Furthermore, the second electrode 20 is disposed on the surface of the N-type epitaxial layer 11a in the first region R1 of the epitaxial layer 11 and is electrically connected to it. The second electrode 20 can be made of the same metal material as the first electrode 13, which will not be described in detail here.

[0062] Since surface-emitting laser elements in gallium arsenide (GaAs) systems primarily utilize epitaxial materials such as aluminum arsenide (AlAs), aluminum gallium arsenide (AlxGa(1-x)As), and gallium arsenide (GaAs), these materials exhibit poor thermal conductivity. Furthermore, the heat diffusion path formed by the light-emitting element 1 at the PN junction near the oxide aperture 11e between the two current-blocking layers 11d is confined to a small, point-like area. Therefore, it is crucial to effectively address the issue of poor heat dissipation in VCSEL elements. In light of this, see combined references. Figure 1 and Figure 2A , Figure 2B In particular, the present invention provides a groove 16 on the opposite side of the epitaxial layer 11 opposite to the light emission aperture 13a, and fills the groove 16 with heat dissipation metal 23. This heat dissipation metal 23 can be further physically connected to a heat sink 2, so that when an external current is introduced into the first electrode 13 and flows into the active layer 11b through the current confinement region, the active layer 11b will excite a light to radiate outward through the current confinement region and the light emission aperture 13a to the epitaxial layer 11. On the other hand, the heat energy generated by the light emission of the active layer 11b in the current confinement region can be dissipated to the outside through the heat dissipation metal 23 recessed in the groove 16 inside the epitaxial layer 11.

[0063] like Figure 2A As shown, compared to the heat dissipation path of the aforementioned cosine function heat dissipation model, the heat dissipation metal 23 within the groove 16 has a shorter heat dissipation path from the active layer 11b, which generates heat in the current-limited region. Therefore, it can effectively dissipate heat. It should be noted that, for ease of explanation, Figure 2A By magnifying the size of the oxide aperture 11e, it is clear that the heat dissipation path between the active layer 11b and the heat dissipation metal 23 near the oxide aperture 11e has been substantially shortened, such as... Figure 2A The heat dissipation range shown by the dashed line already encompasses the heat dissipation metal 23 within the groove 16. Preferably, the groove 16 further penetrates the active layer 11b, allowing the heat dissipation metal 23 within the groove 16 to be closer to the heat source within the current-limited region. In a preferred embodiment, the groove 16 is an annular groove, such as... Figure 2A The enlarged schematic diagram shown on the right shows that the annular structure of the annular groove can completely surround the current-limiting region and the active layer in a three-dimensional manner, making the heat dissipation metal covering the annular groove more efficient in heat dissipation and solving the problem of poor heat dissipation efficiency of point heat sources in traditional VCSEL components.

[0064] Please refer to the following together. Figures 3 to 16 This illustrates a method for manufacturing the VCSEL light-emitting element of the present invention. For example... Figure 3As shown, the epitaxial layer 11 includes an N-type epitaxial layer 11a, an active layer 11b, and a P-type epitaxial layer 11c. It is formed on an epitaxial growth substrate 100 using a group III-V semiconductor material or a group II-VI semiconductor material via metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). In this embodiment, the epitaxial growth substrate 100 can be, for example, but not limited to, an N-type gallium arsenide (GaAs) substrate. Furthermore, an aluminum high-aluminum layer (not shown) is also present above the active layer 11b in the epitaxial layer 11. This aluminum high-aluminum layer can be an aluminum arsenide (AlAs) layer or an aluminum gallium arsenide layer (AlxGa(1-x)As, x≥0.98), which is oxidized in a subsequent oxidation process to form a current barrier layer.

[0065] Figure 4 An insulating layer 12 is formed on the surface of the epitaxial layer 11, and a patterning process is performed on this insulating layer 12 to pattern and etch out ohmic contact positions with the P-type epitaxial layer 11c. Next, as... Figure 5 As shown, a P-type metal vapor deposition process is performed to form a first electrode 13 on the insulating layer 12. This first electrode 13 forms an ohmic contact with and is electrically connected to the P-type epitaxial layer 11c. The first electrode 13 is made of a metallic material selected from one or a combination of silver (Ag), titanium (Ti), platinum (Pt), germanium (GeAu), and gold (Au). Subsequently, the first electrode 13 is patterned and etched to form a light-emitting aperture 13a, as shown. Figure 6 As shown. Additionally, please refer to... Figure 7 This is shown by depositing a BCB (benzocyclobutene) layer 14 on the insulating layer 12, and then bonding it to the BCB layer 14 on one side of another substrate 10. This substrate 10 can be a transparent substrate such as glass or sapphire. After the two wafers are bonded, the epitaxial growth substrate 100 is removed, as shown below. Figure 8 As shown.

[0066] Please see Figure 9 An insulating layer 15 is formed on the epitaxial layer 11 side. Next, the epitaxial layer 11 is patterned and etched to form a trench 16 on the opposite side of the epitaxial layer 11 to the light-emitting aperture 13a. As described above, in a preferred embodiment, this trench 16 is a three-dimensional annular trench penetrating the active layer 11b, effectively shortening the heat dissipation path of the active layer and improving heat dissipation efficiency. Figure 10As shown. Furthermore, this invention utilizes the feature of the groove 16 penetrating the active layer 11b to perform wet oxidation treatment on the relative position of the high-aluminum layer in the aforementioned epitaxial layer on the sidewall of the annular groove. This allows the oxide layer to be precisely formed from the sidewall of the groove towards the active layer 11b inside the epitaxial layer, 0.5 to 1 micrometer (μm) above it. This serves as a current-blocking layer 11d in the current-limiting region, and the current-blocking layer 11d can appropriately surround the oxide aperture 11e to limit the current and light emission of the device, such as... Figure 11 As shown.

[0067] Secondly, please refer to Figure 12 The epitaxial layer 11 is patterned by etching to form a trench 17 and a longitudinal through-hole 18, and the entire epitaxial layer 11 is then subjected to mesa etching. The trench 17 longitudinally divides the epitaxial layer 11 into a first region R1 and a second region R2, effectively separating the epitaxial layer 11 into two distinct parts. The longitudinal through-hole 18 is located in the second region R2, penetrating the epitaxial layer 11 and the insulating layer 12 to expose a portion of the first electrode 13, which will then form part of the subsequent electrode wiring. In actual manufacturing, the trench 17 and the longitudinal through-hole 18 can be formed by either wet etching or dry etching. Furthermore, the trench 17 may be left unfilled or filled with an elastic material, as long as it can withstand stress and prevent epitaxial layer fracture. Next, please refer to... Figure 13 An insulating layer 19 is formed to completely cover the groove 16, the trench 17, the longitudinal through hole 18, and other exposed surfaces. Next, a photolithography process is performed to expose the predetermined areas of the second electrode of the light-emitting element 1 and the two metal pads, such as... Figure 14 As shown.

[0068] Please see Figure 15The process involves a metal vapor deposition process. First, a second electrode 20 is formed, covering the surface of the groove 16 in the first region and the exposed surface of the N-type epitaxial layer 11a corresponding to the current-limited region above, to form a complete circuit loop for the VCSEL element corresponding to the first electrode 13. Next, a metal vapor deposition process is performed to form a first metal pad 21 and a second metal pad 22, respectively, electrically connecting them to the first electrode 13 and the second electrode 20. The first metal pad 21 is the P-side pad of the light-emitting element 1, serving as the positive electrode of the flip-chip type light-emitting chip. It is filled in the vertical through-hole 18 and disposed below the N-type epitaxial layer 11a in the second region R2 of the epitaxial layer 11, extending vertically and electrically connected to the first electrode 13. The second metal pad 22 is the N-side pad of the light-emitting element 1, serving as the negative electrode of the flip-chip type light-emitting chip. It is disposed in the first region R1 of the epitaxial layer 11 and electrically connected to the second electrode 20. The first metal pad 21 and the second metal pad 22 are made of the same material, namely, a metal material selected from one or a combination of silver (Ag), titanium (Ti), platinum (Pt), germanium (GeAu), and gold (Au).

[0069] Please see Figure 16 The illustration shows that, before the actual application of the light-emitting element 1 of the present invention in the packaging structure, a heat-dissipating metal 23 needs to be further filled to cover the groove 16 in the first region R1 and the area below the second metal pad 22, and the heat-dissipating metal 23 is filled and covers the area below the first metal pad 21 in the second region R2, so that the heat-dissipating metal 23 can be further bonded to the surface of the first metal pad 21. Figure 2A The thermal well 2 of the chip package structure shown forms a physical ohmic contact, thereby rapidly transferring heat generated inside the chip to the outside. Specifically, if eutectic bonding is used in the later-stage application, an AuSn alloy with a gold-to-tin ratio of 8:2 can be used as the heat dissipation material. On the other hand, if nano-Ag Silver with Sintering is used in the later-stage application, pure gold is preferable as the heat dissipation material.

[0070] Please see Figures 17 to 19 For example, it illustrates several packaging schemes that specifically apply the present invention. Among them, Figure 17 This diagram shows the packaging structure of the light-emitting element 1 of the present invention applied to a TO-CAN (Transistor Outline CAN) laser bracket, which is paired with a heat dissipation substrate with copper bumps as a heat sink 2, enabling it to... Figure 17The three-dimensional recessed heat dissipation structure, indicated by the dashed circle, rapidly transfers the high heat generated within the current-confined area of ​​the flip-chip LED to the outside, freeing it from the limitations of a point-source heat dissipation model. Secondly, Figure 18 This diagram shows a packaging structure of the light-emitting element 1 of the present invention applied to another copper substrate. Figure 18 The heat sink 2 shown uses a copper substrate with pre-coated resin copper foil in RCC (Resin-Coated Copper) material or a resin substrate in BT (Bismaleimide Triazine) material as a heat dissipation packaging base, which can also quickly heat sinks such as... Figure 18 The high heat generated in the current-confined region, indicated by the dashed circle, is transferred outwards. Additionally, at... Figure 19 The diagram shows a schematic of a packaging structure in which the light-emitting element 1 of the present invention is applied to a thermal collector 2 using an aluminum nitride ceramic substrate. Similarly, Figure 19 The three-dimensional groove heat dissipation structure of the present invention, as indicated by the dotted circle, can also quickly dissipate heat to the outside, overcoming the shortcomings of traditional limited point heat sources that are not easy to dissipate heat.

[0071] Please see Figure 20 This document shows a flowchart of the manufacturing steps of the VCSEL light-emitting element of the present invention. First, in step S01, an epitaxial layer is provided, the epitaxial layer having an active layer. In step S02, a first electrode is provided on the epitaxial layer, the first electrode having a light-emitting aperture. In step S03, a trench is provided on a side of the epitaxial layer opposite to the light-emitting aperture. Next, in step S04, the trench is oxidized with moisture to form a current-confined region on the active layer. In step S05, a second electrode is provided, covering a surface of the trench. Finally, in step S06, a heat-dissipating metal is provided, covering the trench. When a current flows through the first electrode and the current-confined region into the active layer, the active layer will excite light to pass through the current-confined region and the light-emitting aperture before exiting the epitaxial layer. The heat generated by the active layer within the current-confined region is dissipated to the outside via the heat-dissipating metal in the trench. Detailed explanations can be found above and will not be repeated here.

[0072] The above embodiments are merely illustrative of implementation schemes of the present invention and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or equivalent arrangements that can be easily made by those skilled in the art are within the scope of protection claimed by the present invention, and the scope of protection of the present invention should be determined by the claims.

Claims

1. A light-emitting element, comprising: An epitaxial layer having a current-confined region and an active layer; A first electrode is disposed on the epitaxial layer and has a light-emitting hole. When a current flows into the active layer through the first electrode and the current-limited region, the active layer will excite a light to pass through the current-limited region and the light-emitting hole and exit the epitaxial layer. A groove is provided on a side opposite to the light-emitting aperture of the epitaxial layer; A second electrode, covering one surface of the groove; and A heat-dissipating metal covers the groove, allowing the heat generated by the active layer within the current-limited region to be dissipated to the outside via the heat-dissipating metal in the groove.

2. The light-emitting element as claimed in claim 1, wherein the groove extends through the active layer.

3. The light-emitting element as claimed in claim 2, wherein the groove is an annular groove, such that the heat-dissipating metal covering the annular groove surrounds the current-limiting region and the active layer.

4. The light-emitting element as claimed in claim 1, wherein the heat-dissipating metal is one of a tin-gold alloy or gold.

5. The light-emitting element as claimed in claim 1, wherein the epitaxial layer further has a trench that penetrates the epitaxial layer and longitudinally divides the epitaxial layer into a first region and a second region that are separated from each other.

6. The light-emitting element as claimed in claim 5, wherein the groove is disposed in the first region of the epitaxial layer, and the second region of the epitaxial layer has a longitudinal through hole.

7. The light-emitting element as claimed in claim 6 further comprises a first metal pad and a second metal pad, wherein the first metal pad is disposed in the second region and extends longitudinally along the longitudinal through hole to be electrically connected to the first electrode, and the second metal pad is disposed in the first region and electrically connected to the second electrode.

8. A method for manufacturing a light-emitting element, comprising: An epitaxial layer is provided, the epitaxial layer having an active layer; A first electrode is provided and disposed on the epitaxial layer, the first electrode having a light-emitting aperture; A groove is provided on a side opposite to the light-emitting aperture of the epitaxial layer; Moisture oxidizes the trench to form a current confinement region on the active layer; A second electrode is provided, covering one surface of the groove; and Provide a heat-dissipating metal to cover the groove. in, When a current flows through the first electrode and the current-limited region into the active layer, the active layer will excite a light to pass through the current-limited region and the light-emitting aperture and exit the epitaxial layer. The heat generated by the active layer in the current-limited region can be dissipated to the outside through the heat dissipation metal in the groove.

9. The method of manufacturing a light-emitting element as claimed in claim 8, wherein the step of providing a groove is to provide an annular groove penetrating the active layer, such that the heat-dissipating metal covers the annular groove to surround the current-limiting region and the active layer.

10. The method for manufacturing a light-emitting element as claimed in claim 9, wherein the step of oxidizing the annular groove with moisture is to form a current-blocking layer on the active layer, wherein the current-blocking layer has an oxide pore size for use as the current-limiting region.

11. The method for manufacturing a light-emitting element as claimed in claim 10, wherein the oxide pore size is 5 to 20 micrometers.

12. The method of manufacturing a light-emitting element as claimed in claim 8, wherein the step of providing a heat-dissipating metal is to provide a tin-gold alloy or gold.

13. The method of manufacturing a light-emitting element as claimed in claim 8, further comprising the step of providing a trench through the epitaxial layer to longitudinally divide the epitaxial layer into a first region and a second region that are separate from each other, the second region having a longitudinal through hole.

14. The method for manufacturing a light-emitting element as claimed in claim 13, further comprising the step of providing a first metal pad and a second metal pad, wherein the first metal pad is disposed in the second region and extends longitudinally along the longitudinal through hole and is electrically connected to the first electrode, and the second metal pad is disposed in the first region and is electrically connected to the second electrode.

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