Light emitting diode and light emitting device

Abstract

The application provides a light emitting diode and a light emitting device. The light emitting diode comprises a semiconductor stack, an insulating layer and an electrode hole. The semiconductor stack comprises a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially stacked from an emitting surface to a back surface. The semiconductor stack is provided with a semiconductor step which sequentially passes through the second semiconductor layer, the active layer and extends to the first semiconductor layer from the back surface of the semiconductor stack. The exposed surface of the first semiconductor layer is a first step surface, and the surface of the second semiconductor layer towards the back surface is a second step surface. The insulating layer covers at least the sidewall of the semiconductor step and the first step surface. The electrode hole is arranged in the insulating layer covering the first step surface and exposes part of the surface of the first semiconductor layer. The distance D from the electrode hole to the sidewall of the semiconductor step is greater than or equal to 3 microns. The light emitting diode of the application can improve the uniformity of current distribution in the device, thereby improving the light emitting brightness of the light emitting diode and effectively improving the photoelectric conversion efficiency of the chip.

Description

Technical Field

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

[0002] In recent years, with the improvement of people's living standards, the application of ultraviolet LEDs has become more and more popular. Current UVA band products have become the first choice for applications such as photocuring and photocatalysis. Furthermore, with the continuous progress of technology and the increasing market demand, the market size of the ultraviolet nail polish lamp industry has achieved significant growth.

[0003] Current UV nail polish lamps on the market have extremely high requirements for brightness. To meet this demand, manufacturers are constantly exploring and improving production processes, striving to enhance product performance without increasing costs. However, as product sizes continue to shrink, especially with the increasing brightness of smaller core particles, the technical challenges are gradually increasing. Under current technological conditions, how to achieve increased brightness while maintaining the same process flow has become a pressing technical problem to be solved in the industry. Summary of the Invention

[0004] The purpose of this application is to provide a light-emitting diode and a light-emitting device that can improve the uniformity of current distribution in the device, thereby increasing the brightness of the light-emitting diode and effectively improving the photoelectric conversion efficiency of the chip.

[0005] In a first aspect, this application provides a light-emitting diode (LED) having a light-emitting surface and a back surface disposed opposite to each other, including a semiconductor stack, an insulating layer, and an electrode hole. The semiconductor stack includes a first semiconductor layer, an active layer, and a second semiconductor layer stacked sequentially from the light-emitting surface to the back surface. The semiconductor stack has a semiconductor step that extends from the back surface of the semiconductor stack, sequentially passing through a portion of the second semiconductor layer and the active layer, and extending to the first semiconductor layer. The exposed surface of the first semiconductor layer is a first step surface, and the surface of the second semiconductor layer facing the back surface is a second step surface. The insulating layer at least covers the sidewalls of the semiconductor step and the first step surface. The electrode hole is disposed in the insulating layer covering the first step surface and exposes a portion of the surface of the first semiconductor layer. The distance from the electrode hole to the sidewall of the semiconductor step is D, and D ≥ 3 μm.

[0006] Secondly, this application also provides a light-emitting device, characterized in that it includes a circuit board and a light-emitting diode disposed on the circuit board, wherein the light-emitting diode is the light-emitting diode in the aforementioned solution.

[0007] Compared with the prior art, the beneficial effects of this application include at least the following:

[0008] In the light-emitting diode (LED) of this application, since the distance D from the electrode aperture to the sidewall of the semiconductor step satisfies D≥3μm, it is equivalent to increasing the distance from the electrode aperture connecting the N electrode to the sidewall of the semiconductor step to a certain extent. When the LED of this application is powered on, the current flows from the P electrode to the N electrode. Increasing the distance from the electrode aperture connecting the N electrode to the sidewall of the semiconductor step is equivalent to increasing the current flow path length between the P electrode and the N electrode to a certain extent. This can reduce the congestion effect when the current flows out of the electrode aperture, and alleviate the current accumulation at the bottom of the N electrode, thereby improving the uniformity of current distribution in the device. At the same time, when the LED is powered on, during the recombination process of electrons entering the active layer through the electrode aperture via the first semiconductor layer and undergoing recombination, increasing the distance from the electrode aperture connecting the N electrode to the sidewall of the semiconductor step is also equivalent to increasing the path length of electrons from the electrode aperture to the active layer to a certain extent. This enhances the electron diffusion capability, alleviates the overlap of electrons during diffusion, and thus improves the uniformity of electron distribution. This achieves a significant increase in brightness without changing the process, thereby effectively improving the photoelectric conversion efficiency of the chip. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram illustrating the boundary relationships of the layers of a light-emitting diode according to an embodiment of this application;

[0011] Figure 2 For along Figure 1 A schematic diagram of the cross-sectional structure of the light-emitting diode of AA;

[0012] Figure 3 A schematic diagram of the structure after semiconductor steps are fabricated in a semiconductor stack;

[0013] Figure 4 for Figure 2 First schematic diagram of the local structure at the middle electrode hole and semiconductor step;

[0014] Figure 5 for Figure 2 Second schematic diagram of the partial structure at the middle electrode hole and semiconductor step;

[0015] Figure 6 for Figure 2 Third schematic diagram of the local structure at the middle electrode hole and semiconductor step;

[0016] Figure 7 for Figure 2 Fourth schematic diagram of the local structure at the middle electrode hole and semiconductor step;

[0017] Figure 8 This is a schematic diagram of the structure of a light-emitting device according to an embodiment of this application.

[0018] In the figure: 10, Light Emitting Diode; 1, Semiconductor Stack; 11, First Semiconductor Layer; 12, Active Layer; 13, Second Semiconductor Layer; 2, Semiconductor Step; 21, First Step Surface; 22, Second Step Surface; 3, Insulating Layer; 31, First Insulating Layer; 32, Second Insulating Layer; 4, Electrode Hole; 5, First Electrode Layer; 6, Second Electrode Layer; 7, Metal Layer; 8, Base; 100, Circuit Board. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0021] It should be noted that the main purpose of the accompanying drawings is to clearly illustrate the structural composition of the light-emitting diode in this application. In drawing these drawings, we employed specific methods to more effectively convey the features and functions of the design. To highlight certain structural features, we may have exaggerated the dimensions of some components. This exaggeration is intentional, intended to visually demonstrate these features more clearly, rather than strictly reflecting their actual size. The proportional relationships between different structures in the drawings may not be drawn to actual scale. This adjustment helps to more clearly illustrate the relationships and interactions between the parts, rather than simply showing them according to actual dimensions.

[0022] like Figure 1 , Figure 2 and Figure 3 As shown in the embodiments of this application, a light-emitting diode 10 is provided, having a light-emitting surface and a back surface disposed opposite to each other, including a semiconductor stack 1, an insulating layer 3 and an electrode hole 4.

[0023] The semiconductor stack 1, from the light-emitting surface to the back side, includes a first semiconductor layer 11, an active layer 12, and a second semiconductor layer 13 stacked sequentially. The first semiconductor layer 11 is an n-type semiconductor layer, the active layer 12 is a quantum well layer, and the second semiconductor layer 13 is a p-type semiconductor layer. Optionally, the n-type semiconductor layer, the quantum well layer, and the p-type semiconductor layer are all GaN-based materials. The semiconductor stack 1, also known as an epitaxial layer structure, can be prepared by chemical vapor deposition.

[0024] like Figure 3 As shown, from the back side to the light-emitting surface, a portion of the second semiconductor layer 13, a portion of the active layer 12, and a portion of the first semiconductor layer 11 in the semiconductor stack 1 are removed to form a semiconductor step 2. That is, the semiconductor step 2 extends from the back side of the semiconductor stack 1, passing through a portion of the second semiconductor layer 13 and the active layer 12, and extending to the first semiconductor layer 11. Furthermore, in this application, the surface of the first semiconductor layer 11 exposed by the semiconductor step 2 is called the first step surface 21, and the surface of the second semiconductor layer 13 facing the back side is called the second step surface 22.

[0025] like Figure 2 As shown, the insulating layer 3 at least covers the sidewall of the semiconductor step 2 and the first step surface 21. An electrode hole 4 is disposed in the insulating layer 3 covering the first step surface 21, exposing a portion of the surface of the first semiconductor layer 11. The distance from the electrode hole 4 to the sidewall of the semiconductor step 2 is D, and D ≥ 3 μm. Further, in one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 is ≤ 11 μm.

[0026] Given the size limitation of the small-sized chip, and considering the need to ensure that other performance characteristics of the LED 10 are not degraded or that the degradation is within an acceptable range, such as luminous area and reliability, a relatively large distance D is preferred within the aforementioned range. It should be noted that, as... Figure 4 As shown, when the sidewall of the electrode hole 4 is perpendicular to the first step surface 21, and the sidewall of the semiconductor step 2 is also perpendicular to the first step surface 21, distance D refers to the minimum distance from the sidewall of the electrode hole 4 to the sidewall of the semiconductor step 2.

[0027] like Figure 5 As shown, when the sidewall of the electrode hole 4 is perpendicular to the first step surface 21, and the sidewall of the semiconductor step 2 is an inclined surface, then distance D refers to the vertical distance from the sidewall of the electrode hole 4 to the active layer 12 position at the sidewall of the semiconductor step 2.

[0028] like Figure 6 As shown, when the sidewall of the electrode hole 4 is tilted and the sidewall of the semiconductor step 2 is perpendicular to the first step surface 21, the distance D is the minimum distance from the edge of the bottom surface of the electrode hole 4 (i.e., the exposed first step surface 21) to the sidewall of the semiconductor step 2.

[0029] like Figure 7 As shown, when the sidewall of the electrode hole 4 is tilted, and the sidewall of the semiconductor step 2 is also tilted, then the distance D refers to the vertical distance from the edge of the bottom surface of the electrode hole 4 to the active layer 12 position at the sidewall of the semiconductor step 2.

[0030] like Figure 1 As shown, the electrode hole 4 can be a continuous or discontinuous strip, and at least surrounds a portion of the semiconductor step 2.

[0031] like Figure 2 As shown, the light-emitting diode 10 of this application includes a first electrode layer 5 and a second electrode layer 6. The second electrode layer 6 is formed on the surface of the second semiconductor layer 13, and at least a portion of the surface of the second electrode layer 6 facing the light-emitting surface is exposed. The surface of the second electrode layer 6 is covered by an insulating layer 3. The first electrode layer 5 is formed on the surface of the insulating layer 3 and in electrode holes 4, and the first electrode layer 5 is electrically connected to the first semiconductor layer 11 through the electrode holes 4. The insulating layer 3 isolates the first electrode layer 5 from the second electrode layer 6.

[0032] In the prior art, the distance from the electrode hole 4 to the sidewall of the semiconductor step 2 may not be fixed, which leads to uneven current distribution, that is, uneven diffusion of electrons from the electrode hole 4 to the semiconductor step 2, which may cause electron overlap and affect the brightness of light emission.

[0033] In the light-emitting diode 10 of this application, since the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies D≥3μm, it is equivalent to increasing the distance from the electrode hole 4 connecting the N electrode (first electrode layer 5) to the sidewall of the semiconductor step 2 to a certain extent.

[0034] When the light-emitting diode (LED) of this application is powered on, the current flows from the P electrode to the N electrode. Increasing the distance from the electrode hole 4 connecting the N electrode to the sidewall of the semiconductor step 2 is equivalent to increasing the current flow path length between the P electrode and the N electrode to a certain extent. This reduces the congestion effect when the current flows out of the electrode hole 4, alleviating the current accumulation at the bottom of the N electrode and thus improving the uniformity of current distribution in the device. Simultaneously, when the LED is powered on, as electrons enter the active layer 12 through the electrode hole 4 via the first semiconductor layer 11 and recombine, increasing the distance from the electrode hole 4 connecting the N electrode to the sidewall of the semiconductor step 2 is also equivalent to increasing the path length of electrons from the electrode hole 4 to the active layer 12 to a certain extent. This enhances the electron diffusion capability, alleviates the overlap of electrons during diffusion, and improves the uniformity of electron distribution. This achieves a significant increase in brightness without changing the process, thereby effectively improving the photoelectric conversion efficiency of the chip.

[0035] Conversely, in existing technologies, the distance from the electrode holes to the sidewalls of the semiconductor steps in many or all of the existing light-emitting diodes may be less than 3 μm. In this case, the electron overlap will be relatively severe and the electron diffusion uniformity will be relatively poor during the diffusion of electrons from the electrode holes to the active layer.

[0036] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 3μm≤D≤10μm.

[0037] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 3μm≤D≤9μm.

[0038] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 5μm≤D≤11μm.

[0039] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 5μm≤D≤10μm.

[0040] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 7μm≤D≤11μm.

[0041] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 9μm≤D≤11μm.

[0042] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 5μm≤D≤9μm.

[0043] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 5μm≤D≤7μm.

[0044] In one embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 7μm≤D≤9μm.

[0045] Provided that other performance characteristics of the light-emitting diode 10 do not degrade or the degree of degradation is within an acceptable range, and within the aforementioned range of distance D values, a relatively large distance D is preferred.

[0046] In one implementation scheme, such as Figure 2 As shown, the insulating layer 3 of the light-emitting diode 10 generally includes at least a first insulating layer 31 and a second insulating layer 32. The first insulating layer 31 covers at least the sidewall of the semiconductor step 2 and the first step surface 21, and the second insulating layer 32 covers at least the surface of the first insulating layer 31 and the second electrode layer 6.

[0047] In one embodiment, the contact area between the first electrode layer 5 and the first semiconductor layer 11 is S. N(That is, the opening area of ​​the electrode hole), the projected area of ​​the first electrode layer 5 onto a plane parallel to the first step surface 21 is S. O Then S N With S O The ratio relationship can satisfy: 0.01 ≤ S N / S O ≤0.05. For example, S N / S O =0.01, S N / S O =0.02, S N / S O =0.03, S N / S O =0.04, S N / S O =0.05.

[0048] In one implementation scheme, such as Figure 2 As shown, the width of electrode hole 4 is W, and the value of W can satisfy: 2μm≤W≤6μm. For example, W can take the values ​​of 2μm, 3μm, 4μm, 5μm, and 6μm.

[0049] On the one hand, ensuring that the electrode hole 4 has a certain width and area avoids the congestion effect when the current flows out of the electrode hole 4, thereby alleviating the current accumulation at the bottom of the N electrode and improving the uniformity of the current distribution in the device. On the other hand, under the premise that other performance of the light-emitting diode 10 does not degrade or the degree of degradation is within an acceptable range, by adjusting the width W and area of ​​the electrode hole 4, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 is ensured to be a larger value within the aforementioned limited range. This is equivalent to increasing the path length of electrons from the electrode hole 4 to the active layer 12 to a certain extent, improving the electron expansion capability, reducing electron overlap, and improving the luminous brightness of the light-emitting diode.

[0050] In one embodiment, the distance from the electrode hole 4 to the edge of the light-emitting diode 10 is H, and the value of H can satisfy: 20μm ≤ H ≤ 50μm. For example, H can take values ​​of 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, etc. It should be noted that the distance from the electrode hole 4 to the edge of the light-emitting diode 10 is the minimum distance from the bottom edge of the electrode hole 4 to the edge of the light-emitting diode 10.

[0051] On the one hand, ensuring a certain distance between the electrode hole 4 and the edge of the light-emitting diode 10 avoids abnormal impacts on the quality of the light-emitting diode caused by cutting and scratching. On the other hand, under the premise that other performance of the light-emitting diode 10 does not degrade or the degree of degradation is within an acceptable range, by adjusting the distance H between the electrode hole 4 and the edge of the light-emitting diode 10, the distance D between the electrode hole 4 and the sidewall of the semiconductor step 2 is ensured to be a larger value within the aforementioned limited range. This increases the path length of electrons from the electrode hole 4 to the active layer 12, enhances the electron expansion capability, reduces electron overlap, and improves the luminous brightness of the light-emitting diode.

[0052] In one implementation scheme, such as Figure 2 As shown, the light-emitting diode 10 can be square or rectangular. The light-emitting diode 10 has a shortest side with a length of L, where 200μm≤L≤260μm. For example, L can take values ​​of 200μm, 210μm, 220μm, 230μm, 240μm, 250μm, 260μm, etc.

[0053] In one embodiment, the ratio of the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 to the shortest side L of the light-emitting diode satisfies: 1 / 80 ≤ D / L ≤ 1 / 20. For example, D / L = 1 / 80, D / L = 1 / 60, D / L = 1 / 40, D / L = 1 / 20.

[0054] Given the size limitation of the small-sized chip, and since it is also necessary to ensure that other performance characteristics of the LED 10 do not degrade or that the degree of degradation is within an acceptable range, such as the light-emitting area and reliability, the appropriate value range is within the range of the ratio 1 / 80≤D / L≤1 / 20, and within the aforementioned range of distance D and size L.

[0055] In one embodiment, the shortest side length L of the light-emitting diode can satisfy 230μm≤L≤260μm, the distance from electrode hole 4 to the sidewall of semiconductor step 2 is D2, and the distance from electrode hole 4 to the edge of light-emitting diode 10 is H2. Then the ratio of D2 to H2 can satisfy: 0.2≤D2 / H2≤0.4.

[0056] Under the condition of 230μm≤L≤260μm, the width W of the electrode hole 4 is preferably 4μm≤W≤6μm. If the value of D2 / H2 is less than 0.2, it may easily cause current to accumulate at the bottom of the N electrode (first electrode layer 5), which will not play a positive role in improving the uniformity of current distribution. If the value of D2 / H2 is greater than 0.4, it will result in a longer impedance distance, which will lead to a certain degree of voltage increase.

[0057] In one embodiment, the shortest side length L of the light-emitting diode can satisfy 200μm≤L≤230μm. The distance from the electrode hole 4 to the sidewall of the semiconductor step 2 is D1, and the distance from the electrode hole 4 to the edge of the light-emitting diode 10 is H1. Then the ratio of D1 to H1 can satisfy: 0.1≤D1 / H1≤0.25.

[0058] Under the condition of 200μm≤L≤230μm, the width W of the electrode hole 4 is preferably 2μm≤W≤4μm. Since the core size is smaller at this time, if the value of D1 / H1 is greater than 0.25, it will result in a smaller area of ​​the light-emitting region. If the value of D1 / H1 is less than 0.1, it means that the electrode hole 4 is too close to the sidewall of the semiconductor step 2, which can easily lead to uneven current distribution, that is, uneven electron diffusion, resulting in lower brightness.

[0059] In one embodiment, the first electrode layer 5 of the light-emitting diode 10 is configured as a Cr material layer at the position facing the light-emitting surface and in contact with the first semiconductor layer 11.

[0060] The first semiconductor layer 11 is generally made of GaN-based material. Since the work function of Cr is close to that of GaN, it can play a role in voltage reduction. At the same time, the thickness of the Cr material layer can be 3 to 40 Å, preferably 10 to 15 Å, which can play a certain role in voltage reduction without being too thick and affecting the brightness.

[0061] In one implementation scheme, such as Figure 2 As shown, the light-emitting diode 10 includes a metal layer 7 and a base 8. The metal layer 7 is formed on the surface of the first electrode layer 5 and is bonded to the base 8.

[0062] like Figure 8 As shown, this application also provides a light-emitting device, including a circuit board 100 and a light-emitting diode 10 disposed on the circuit board 100, wherein the light-emitting diode 10 is the light-emitting diode 10 in the aforementioned solution.

[0063] To provide a more detailed explanation of the LED solution and its effects, the following embodiments are provided. It should be noted that the technical features in the following embodiments can be used in combination without conflict.

[0064] Example 1

[0065] like Figure 2 As shown, this embodiment provides a light-emitting diode 10, which has a light-emitting surface and a back surface disposed opposite to each other, including a semiconductor stack 1, an insulating layer 3, an electrode hole 4, a first electrode layer 5, and a second electrode layer 6.

[0066] The semiconductor stack 1, from the light-emitting surface to the back side, includes a first semiconductor layer 11, an active layer 12, and a second semiconductor layer 13 stacked sequentially. The first semiconductor layer 11 is an n-type semiconductor layer, the active layer 12 is a quantum well layer, and the second semiconductor layer 13 is a p-type semiconductor layer. Optionally, the n-type semiconductor layer, the quantum well layer, and the p-type semiconductor layer are all GaN-based materials. The semiconductor stack 1, also known as an epitaxial layer structure, can be prepared by chemical vapor deposition.

[0067] like Figure 3 As shown, from the back side to the light-emitting surface, a portion of the second semiconductor layer 13, a portion of the active layer 12, and a portion of the first semiconductor layer 11 in the semiconductor stack 1 are removed to form a semiconductor step 2. That is, the semiconductor step 2 passes through the second semiconductor layer 13 and the active layer 12 sequentially from the back side of the semiconductor stack 1 and extends to the first semiconductor layer 11. Furthermore, the surface of the first semiconductor layer 11 exposed by the semiconductor step 2 is called the first step surface 21, and the surface of the second semiconductor layer 13 facing the back side is called the second step surface 22.

[0068] The insulating layer 3 covers at least the sidewalls of the semiconductor step 2 and the first step surface 21. The electrode hole 4 is disposed in the insulating layer 3 covering the first step surface 21 and exposes part of the surface of the first semiconductor layer 11.

[0069] The second electrode layer 6 is formed on the surface of the second semiconductor layer 13. At least a portion of the surface of the second electrode layer 6 facing the light-emitting surface is exposed, and the surface of the second electrode layer 6 is covered by the insulating layer 3. The first electrode layer 5 is formed on the surface of the insulating layer 3 and in the electrode holes 4, and the first electrode layer 5 is electrically connected to the first semiconductor layer 11. The insulating layer 3 isolates the first electrode layer 5 from the second electrode layer 6. Additionally, a conductive layer and a reflective layer (not shown in the figure) are generally disposed between the second electrode layer 6 and the active layer 12.

[0070] The insulating layer 3 of the light-emitting diode 10 generally includes at least a first insulating layer 31 and a second insulating layer 32. The first insulating layer 31 covers at least the sidewalls of the semiconductor step 2 and the first step surface 21, and the second insulating layer 32 covers at least the surface of the first insulating layer 31 and the second electrode layer 6.

[0071] In this embodiment, the distance from electrode hole 4 to the sidewall of semiconductor step 2 is D, where D ≥ 3 μm. Preferably, the distance D from electrode hole 4 to the sidewall of semiconductor step 2 satisfies: 3 μm ≤ D ≤ 11 μm.

[0072] In this embodiment, the contact area between the first electrode layer 5 and the first semiconductor layer 11 is S. N (That is, the opening area of ​​the electrode hole), the projected area of ​​the first electrode layer 5 onto a plane parallel to the first step surface 21 is S. O Then SN With S O The ratio relationship can satisfy: 0.01 ≤ S N / S O ≤0.05.

[0073] In this embodiment, the width of electrode hole 4 is W, and the value of W can satisfy: 2μm≤W≤6μm.

[0074] In this embodiment, the distance from the electrode hole 4 to the edge of the light-emitting diode 10 is H, and the value of H can satisfy: 20μm≤H≤50μm.

[0075] In this embodiment, the light-emitting diode 10 can be square or rectangular, and the light-emitting diode 10 has a shortest side with a length of L, where 200μm≤L≤260μm.

[0076] In this embodiment, the first electrode layer 5 of the light-emitting diode 10 is configured as a Cr material layer at the position facing the light-emitting surface and in contact with the first semiconductor layer 11.

[0077] In this embodiment, the first electrode layer 5 of the light-emitting diode 10 may include a first Cr material layer, an Al material layer and a second Cr material layer stacked sequentially from the light-emitting surface to the back surface.

[0078] The first semiconductor layer 11 is generally made of GaN-based material. Since the work function of Cr is close to that of GaN, it can play a role in voltage reduction. At the same time, the thickness of the first Cr material layer can be 3 to 40 Å, preferably 10 to 15 Å, which can play a certain role in voltage reduction without being too thick and affecting the brightness.

[0079] In this embodiment, the light-emitting diode 10 includes a metal layer 7 and a base 8. The metal layer 7 is formed on the surface of the first electrode layer 5 and is bonded to the base 8.

[0080] In the light-emitting diode 10 of this embodiment, since the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies D≥3μm, and preferably 3μm≤D≤11μm, the distance from the electrode hole 4 connecting the N electrode (first electrode layer) to the sidewall of the semiconductor step 2 is increased to a certain extent. This is equivalent to increasing the current flow path length between the P electrode and the N electrode. This can reduce the congestion effect when the current flows out of the electrode hole 4, and alleviate the current accumulation at the bottom of the N electrode, thereby improving the uniformity of the current distribution in the device.

[0081] Meanwhile, when the light-emitting diode is powered on, electrons enter the active layer 12 through the first semiconductor layer 11 from the electrode hole 4 and recombine. This increases the distance from the electrode hole 4 connecting the N electrode to the sidewall of the semiconductor step 2, which is equivalent to increasing the path length of electrons from the electrode hole 4 to the active layer 12 to a certain extent. This enhances the electron diffusion capability, alleviates the overlap of electrons during diffusion, and improves the uniformity of electron distribution. This achieves a significant brightening effect without changing the process, thereby effectively improving the photoelectric conversion efficiency of the chip.

[0082] Example 2

[0083] This embodiment also provides a light-emitting diode. The difference between this embodiment and embodiment one is that the range of values ​​for the length L of the shortest side of the light-emitting diode 10, the range of values ​​for the width W of the electrode hole 4, and the range of values ​​for the ratio D / H of the distance from the electrode hole 4 to the sidewall of the semiconductor step 2 and the distance from the electrode hole 4 to the edge of the light-emitting diode 10 are different from those in embodiment one.

[0084] Specifically, in this embodiment, the length L of the shortest side of the light-emitting diode 10 satisfies 200μm≤L≤230μm, and the width W of the electrode hole 4 satisfies 2μm≤W≤4μm. The distance from the electrode hole 4 to the sidewall of the semiconductor step 2 is D1, and the distance from the electrode hole 4 to the edge of the light-emitting diode 10 is H1. The ratio of D1 to H1 can satisfy: 0.1≤D1 / H1≤0.25. It should be noted that in this embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 also satisfies 3μm≤D≤11μm.

[0085] In this embodiment, to maximize the value of D within the range of 3μm ≤ D ≤ 11μm, the following methods can be used. First, while keeping the width W of the electrode hole 4 constant, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 can be increased by decreasing the distance H from the electrode hole 4 to the edge of the LED 10. Second, while keeping the distance H from the electrode hole 4 to the edge of the LED 10 constant, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 can be increased by decreasing the width W of the electrode hole 4. Especially as product dimensions continue to shrink, if the distance H from the electrode hole 4 to the edge of the LED 10 is too small, it may increase the scratch rate, leading to chip yield loss. Therefore, it is necessary to ensure that the electrode hole 4 has a certain distance from the edge of the LED 10, which can be achieved by decreasing the width W of the electrode hole 4 to increase the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2. Third, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 can be increased by reducing the width W of the electrode hole 4 and simultaneously reducing the distance H from the electrode hole 4 to the edge of the light-emitting diode 10. This ensures that the other performance of the light-emitting diode 10 is not degraded or that the degree of degradation is within an acceptable range. Within the aforementioned range of distance D, the width W and distance H can be selected relatively appropriately based on the change in size L.

[0086] Under the conditions of 3μm≤D≤11μm, 200μm≤L≤230μm and 2μm≤W≤4μm, if the value of D1 / H1 is greater than 0.25, the area of ​​the light-emitting region will be too small. If the value of D1 / H1 is less than 0.1, it means that the electrode hole 4 is too close to the sidewall of the semiconductor step 2, which is prone to uneven current distribution, that is, uneven electron diffusion, resulting in lower brightness.

[0087] Therefore, under the conditions of 3μm≤D≤11μm, 200μm≤L≤230μm and 2μm≤W≤4μm, the ratio of D1 to H1 satisfies 0.1≤D1 / H1≤0.25, which can ensure sufficient light-emitting area and improve the uniformity of current distribution, that is, improve the uniformity of electron diffusion and improve the brightness of light-emitting diode.

[0088] Example 3

[0089] This embodiment also provides a light-emitting diode. The difference between this embodiment and embodiment two is that the range of values ​​for the length L of the shortest side of the light-emitting diode 10, the range of values ​​for the width W of the electrode hole 4, and the range of values ​​for the ratio D / H of the distance from the electrode hole 4 to the sidewall of the semiconductor step 2 and the distance from the electrode hole 4 to the edge of the light-emitting diode 10 are different from those in embodiment two.

[0090] Specifically, in this embodiment, the length L of the shortest side of the light-emitting diode 10 satisfies 230μm≤L≤260μm. The width W of the electrode hole 4 satisfies 4μm≤W≤6μm. The distance D2 from the electrode hole 4 to the sidewall of the semiconductor step 2 and the distance H2 from the electrode hole 4 to the edge of the light-emitting diode 10 can satisfy: 0.2≤D2 / H2≤0.4.

[0091] It should be noted that in this embodiment, the distance from electrode hole 4 to the sidewall of semiconductor step 2 is D, which also satisfies 3μm≤D≤11μm.

[0092] Under the conditions of 3μm≤D≤11μm, 230μm≤L≤260μm, and 4μm≤W≤6μm, if the value of D2 / H2 is less than 0.2, it will easily cause current to accumulate at the bottom of the N electrode (first electrode layer 5), and will not play a positive role in improving the uniformity of current distribution. If the value of D2 / H2 is greater than 0.4, it will result in a longer impedance distance, which will lead to an increase in voltage.

[0093] Therefore, under the conditions of 3μm≤D≤11μm, 230μm≤L≤260μm, and 4μm≤W≤6μm, the ratio of D2 to H2 satisfies 0.2≤D2 / H2≤0.4. This can alleviate the current accumulation at the bottom of the N electrode (first electrode layer 5), helping to improve the uniformity of current distribution, that is, improving the uniformity of electron diffusion from electrode hole 4 to semiconductor step 2, thus enhancing the brightness of the light-emitting diode. At the same time, it also ensures that the impedance distance is within a reasonable range, without causing excessive voltage rise.

[0094] Example 4

[0095] This embodiment also provides a light-emitting diode. The difference between this embodiment and embodiments one, two or three is that the range of the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 is different from that in embodiments one, two or three.

[0096] Specifically, in embodiments one, two, or three, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 3μm≤D≤11μm. In this embodiment, the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 satisfies 5μm≤D≤11μm, for example, a value of 5.5μm.

[0097] Example 5

[0098] This embodiment also provides a light-emitting diode. The difference between this embodiment and embodiment four is that the range of the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 is different from that in embodiment four.

[0099] Specifically, in this embodiment, the distance D from electrode hole 4 to the sidewall of semiconductor step 2 satisfies 7μm≤D≤11μm. For example, a value of 7.5μm is used.

[0100] Example 6

[0101] This embodiment also provides a light-emitting diode. The difference between this embodiment and embodiment five is that the range of the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2 is different from that in embodiment five.

[0102] Specifically, in this embodiment, the distance D from electrode hole 4 to the sidewall of semiconductor step 2 satisfies 9μm≤D≤11μm. For example, a value of 9.5μm is used.

[0103] For the schemes of Embodiments 4, 5 and 6, a value was taken within the range of their respective distance D (distance from electrode hole 4 to the sidewall of semiconductor step 2), and experiments were conducted to statistically analyze the changes in brightness and voltage. The experimental results are shown in Table 1.

[0104] Table 1. Statistical table of operating data for different values ​​of the distance from the electrode hole to the sidewall of the semiconductor step.

[0105] Technical solution Distance D (μm) VF (Operating Voltage) △VF LOP (Lightness) △LOP Example 4 5.5 3.822 0.000 115.324 0.0％ Example 5 7.5 3.832 0.010 115.995 0.6％ Example 6 9.5 3.843 0.022 117.081 1.5％

[0106] It should be noted that the main difference between Embodiments 4 to 6 in Table 1 is the difference in the distance D from the electrode hole 4 to the sidewall of the semiconductor step 2. The opening areas of the electrode holes 4 are basically equal, and the opening area of ​​the electrode holes 4 is also the contact area S between the first electrode layer 5 and the first semiconductor layer 11. N .

[0107] It should also be noted that when calculating △VF and △LOP, the VF and LOP data of Example 4 are used as a comparative example.

[0108] As can be seen from the data in Table 1, the distance D from electrode hole 4 to the sidewall of semiconductor step 2 ranges from 3μm to 11μm. The larger the value of distance D, the larger the LOP value, indicating a brighter light output. Correspondingly, although the operating voltage of the LED will increase slightly, the voltage rise is very small and can be almost ignored.

[0109] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A light emitting diode having opposite light emitting and back surfaces, characterized by The application relates to a light emitting diode. The light emitting diode comprises: a semiconductor stack (1) comprising, from the light emitting surface to the back surface, a first semiconductor layer (11), an active layer (12) and a second semiconductor layer (13) arranged in sequence; the semiconductor stack (1) is provided with a semiconductor step (2) extending from the back surface of the semiconductor stack (1) through part of the second semiconductor layer (13) and the active layer (12) in sequence and to the first semiconductor layer (11), the surface of the exposed first semiconductor layer (11) being a first step surface (21), and the surface of the second semiconductor layer (13) facing the back surface being a second step surface (22); an insulating layer (3) covering at least the sidewall of the semiconductor step (2) and the first step surface (21); an electrode hole (4) arranged in the insulating layer (3) covering the first step surface (21) and exposing part of the surface of the first semiconductor layer (11); 2. The light emitting diode of claim 1, wherein, wherein the distance from the electrode hole (4) to the sidewall of the semiconductor step (2) is D, and D>=3 mu m.

3. The light emitting diode of claim 1, wherein, The distance D from the electrode hole (4) to the sidewall of the semiconductor step (2) satisfies D<=11 mu m.

4. The light emitting diode of claim 1, wherein, The electrode hole (4) is a continuous or discontinuous strip and at least surrounds part of the semiconductor step (2). The light emitting diode comprises a first electrode layer (5) and a second electrode layer (6); The second electrode layer (6) is formed on the surface of the second semiconductor layer (13), and at least part of the surface of the second electrode layer (6) facing the light emitting surface is exposed; the surface of the second electrode layer (6) is covered by the insulating layer (3); The first electrode layer (5) is formed on the surface of the insulating layer (3) and in the electrode hole (4), and the first electrode layer (5) is electrically connected to the first semiconductor layer (11) through the electrode hole (4); 5. The light emitting diode of claim 4, wherein, The insulating layer (3) separates the first electrode layer (5) from the second electrode layer (6). The insulating layer (3) comprises a first insulating layer (31) and a second insulating layer (32); The first insulating layer (31) covers at least the sidewall of the semiconductor step (2) and the first step surface (21); 6. The light emitting diode of claim 4, wherein, The contact area of the first electrode layer (5) with the first semiconductor layer (11) is S N , the projected area of the first electrode layer (5) onto a plane parallel to the first step face (21) is S O , and 0.01 ≤ S N / S O ≤ 0.

05.

7. The light emitting diode of claim 1, wherein, The second insulating layer (32) covers at least the surface of the first insulating layer (31) and the second electrode layer (6).

8. The light emitting diode of claim 1, wherein, The width of the electrode hole (4) is W, and 2 mu m<=W<=6 mu m.

9. The light emitting diode of claim 1, wherein, The distance from the electrode hole (4) to the edge of the light emitting diode is H, and 20 mu m<=H<=50 mu m.

10. The light emitting diode of claim 9, wherein, The light emitting diode has a shortest side, and the length of the shortest side is L, and 200 mu m<=L<=260 mu m.

11. The light emitting diode of claim 1, wherein, The ratio of the distance D from the electrode hole (4) to the sidewall of the semiconductor step (2) to the shortest side L of the light emitting diode satisfies 1 / 80<=D / L<=1 / 20. The length of the shortest side of the light emitting diode is L, and 200 mu m<=L<=230 mu m, the distance from the electrode hole (4) to the sidewall of the semiconductor step (2) is D1, and the distance from the electrode hole (4) to the edge of the light emitting diode is H1, wherein 0.1<=D1 / H1<=0.

25.

12. The light emitting diode of claim 1, wherein, The shortest side length of the light emitting diode is L, and 230um≤L≤260um, the distance from the electrode hole (4) to the side wall of the semiconductor step (2) is D2, the distance from the electrode hole (4) to the edge of the light emitting diode is H2, wherein 0.2≤D2 / H2≤0.

4.

13. The light emitting diode of claim 4, wherein, The position of the first electrode layer (5) towards the light emitting surface side and in contact with the first semiconductor layer (11) is provided as a Cr material layer.

14. The light emitting diode of claim 13, wherein, The thickness of the Cr material layer is 3-40A.

15. The light emitting diode of claim 4, wherein, The light emitting diode comprises a metal layer (7) and a pedestal (8), the metal layer (7) is formed on the surface of the first electrode layer (5), and the metal layer (7) is bonded with the pedestal (8).

16. A light emitting device comprising: The circuit substrate (100) and the light emitting diode provided on the circuit substrate (100) are included, and the light emitting diode is the light emitting diode as claimed in any one of claims 1-15.

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