Semiconductor light emitting element and light emitting device

Abstract

A semiconductor light-emitting element comprises: a first conductive type semiconductor layer, a second conductive type semiconductor layer and an active layer therebetween; a current blocking layer, comprising a strip-shaped portion, arranged on a local surface of the first conductive type semiconductor layer; a first metal electrode, comprising a first metal electrode pad and a first metal electrode extension strip extending from the first metal electrode pad, the first metal electrode extension strip being located above the strip-shaped portion of the current blocking layer; the first metal electrode extension strip comprising an extension section and an end portion; the strip-shaped portion of the current blocking layer located below part of the extension section has a gradually widening portion along an extension direction gradually away from the first metal electrode pad.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure relate to a semiconductor light emitting element (LED chip), and more particularly, to a semiconductor light emitting element having high reliability. Background Art

[0002] Generally, a semiconductor light-emitting element is also called a light-emitting diode (LED chip), which includes a first conductive type semiconductor layer for supplying holes, a second conductive type semiconductor layer for supplying electrons, and a light-emitting layer inserted between the first conductive type semiconductor layer and the second conductive type semiconductor layer, wherein the first conductive type semiconductor layer is a p-type layer and the second conductive type semiconductor layer is an n-type layer. A first electrode and a second electrode are respectively formed on the first conductive type semiconductor layer and the second conductive type semiconductor layer to transfer current from an external power source to the light-emitting diode to obtain light emission.

[0003] On the other hand, the first conductive type semiconductor layer based on a nitride semiconductor has a lower conductivity than the second conductive type semiconductor layer. Therefore, the current will not spread effectively in the first conductive type semiconductor layer, resulting in current crowding in a certain area of ​​the semiconductor layer. When current crowding occurs in the semiconductor layer, the light-emitting diode becomes prone to electrostatic discharge and burns. In order to achieve effective current diffusion, a transparent electrode layer such as indium tin oxide (ITO) is formed on the first conductive type semiconductor layer, and the first electrode is formed on the ITO layer, the first electrode includes an electrode pad and a strip portion extending from the electrode pad, and a current blocking layer with the same shape and contour is also provided under the first metal electrode pad and the first electrode strip portion to block the current from extending longitudinally between the first metal electrode and the first conductive type semiconductor layer, which is conducive to the lateral expansion of the current. At present, the current blocking layer under the strip electrode is designed to expand outward to both sides of the finger electrode according to a fixed width gap relative to the width of the electrode extension strip. However, charges are easily concentrated near the ends of the electrode strips, and the electrode strips are easily deviated from the current blocking layer due to inaccurate mask pattern alignment, which can easily lead to failure near the ends under high-level voltage ESD shocks. Summary of the invention

[0004] The present invention provides a semiconductor light emitting element with high reliability, comprising:

[0005] A first conductivity type semiconductor layer, a second conductivity type semiconductor layer and an active layer therebetween;

[0006] A current blocking layer, comprising a strip-shaped portion, is disposed on a partial surface of the first conductive type semiconductor layer;

[0007] A first metal electrode, comprising a first metal electrode pad and a first metal electrode extension strip extending from the first metal electrode pad, wherein the first metal electrode extension strip is located on the strip-shaped portion of the current blocking layer;

[0008] It is characterized in that: the first metal electrode extension strip includes an extension section and an end; the strip portion of the current blocking layer located below part of the extension section has a gradually widening portion along the extension direction gradually away from the first metal electrode pad.

[0009] Beneficial Effects

[0010] With respect to the semiconductor light-emitting element of the present invention, the shape of the current blocking layer below the extended section of the first metal electrode extension strip near the end portion is improved, that is, the current blocking layer has a gradually relatively widened portion along the extension direction gradually away from the first metal electrode pad, thereby improving the phenomenon of excessive concentration of charge distribution under electrostatic shock at the far end of the first metal electrode extension strip, and avoiding current crowding near the far end of the first metal electrode extension strip due to the offset of the position of the current blocking layer, thereby improving ESD performance and improving the reliability of the electrode structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1~2 A top view of a semiconductor light emitting element according to a first embodiment of the present invention, Figure 1 The adjacent dashed lines represent different components of the first metal electrode extension strip (1072, 1073, 1074 and 1075); Figure 2 The adjacent dotted lines represent different components of the strip-shaped portion of the current blocking layer (1052, 1053, 1054 and 1055).

[0012] Figure 3 for Figure 1 Schematic diagram of the partial structure of a semiconductor light-emitting element.

[0013] Figure 4 for Figure 1 Schematic diagram of the cross-sectional structure of a semiconductor light emitting element along line AA'.

[0014] Figure 5 for Figure 4 A cross-sectional view showing a semiconductor light emitting element structure with a transparent protective layer added thereto.

[0015] Figure 6 The semiconductor light emitting element of the first embodiment and Fig.12 The ESD yield comparison data between semiconductor light-emitting components shown.

[0016] Figure 7FIG. 1 is a schematic diagram of a top view of a semiconductor light emitting element according to the second embodiment.

[0017] Figure 8 FIG. 1 is a schematic diagram of a partial structure of a semiconductor light emitting element according to the second embodiment.

[0018] Fig. 9 FIG. 1 is a schematic diagram of a top view of the structure of a semiconductor light emitting element according to the third embodiment.

[0019] Fig.10 for Fig. 9 A local enlarged schematic diagram of the circle A position.

[0020] Fig.11 for Fig. 9 A local enlarged schematic diagram of the circle B position.

[0021] Fig.12 It is a schematic diagram of the top view structure of an existing semiconductor light emitting element.

[0022] Fig.13 For Fig.12 A photograph of an existing semiconductor light-emitting element showing an ESD explosion point.

[0023] Fig.14 for Fig.12 A partial photograph of an existing semiconductor light-emitting element showing an ESD explosion point.

[0024] Fig.15 for Fig.12 A partial photograph of a conventional semiconductor light emitting element before ESD performance testing is shown.

[0025] Reference numerals

[0026] A first conductive type semiconductor layer 102; a second conductive type semiconductor layer 104; an active layer 103; a current blocking layer 105; a strip-shaped portion connecting portion 1051 of the electrode blocking layer, a first length portion 1053 of the current blocking layer; a second length portion 1054 of the current blocking layer; an end enlarged portion 1055 of the current blocking layer; a transparent electrode layer 106, an opening 1061 of the transparent electrode layer; a first metal electrode 107; a first metal electrode pad 1071; a first metal electrode extension strip connecting portion 1072; a straight extension segment 1073 of the first metal electrode extension strip; an arc extension segment 1074 of the first metal electrode extension strip, a folded line extension segment 1074' of the first metal electrode extension strip; an end portion 1075 of the first metal electrode extension strip; a second metal electrode 108; a second metal electrode pad 1081; a second metal electrode extension strip 1082; and a transparent protective layer 109. DETAILED DESCRIPTION

[0027] Throughout the description, the substrate of the present invention is considered to be placed horizontally. Formed on the substrate, a second conductivity type semiconductor layer, an active layer on the second conductivity type semiconductor layer, and a second conductivity type semiconductor layer arranged on the active layer. The meanings of the expressions "upper" and "lower", "above" and "below", or "lower" and "upper" should be considered to be in terms of this placement direction. Unless otherwise specified, the expressions "upper" and "lower", "above" and "below" do not necessarily mean that the upper and lower layers are in direct contact with each other. In addition, the expression "layer" means a material area with a thickness and its composition is used to provide the expected properties. Unless otherwise specified, the expression "layer" may mean a single layer or include multiple sublayers.

[0028] like Fig.12 The schematic diagram of the top view structure of an existing semiconductor light-emitting element shown in the figure includes a first conductive type semiconductor layer 102, a second conductive type semiconductor layer 104, and an active layer 103 between the first conductive type semiconductor layer 102 and the second conductive type semiconductor layer 104; a current blocking layer 105 having a strip-shaped portion, a transparent electrode layer 106; and a first metal electrode 107, including a first metal electrode pad 1071 and a first metal electrode extension strip extending from the first metal electrode pad 1071. The strip-shaped portion of the current blocking layer 105 has a similar shape to the first metal electrode extension strip and is located below the first metal electrode extension strip. The difference in width between the strip-shaped portion of the current blocking layer 105 and the first metal electrode extension strip is fixed in the entire extension direction of the entire first metal electrode extension strip. Because the charge distribution at the far end of the first metal electrode extension strip is too concentrated under the electrostatic shock; and because the mask plate is easily offset during the process of making the first metal electrode, problems such as those reflected in the photos shown in Figures 13 to 15 are likely to occur. The first metal electrode extension strip is easily offset relative to the current blocking layer. In particular, the first metal electrode extension strip has a broken line or curved part near the end, the offset phenomenon is more serious, and the current is easily crowded near the end of the electrode extension strip. ESD explosion points are more likely to occur under the condition of applying electrostatic shock, resulting in poor ESD performance and reduced ESD yield of semiconductor light-emitting elements (that is, the proportion of ESD explosion points in several semiconductor light-emitting elements is reduced).

[0029] Embodiment 1

[0030] Figure 1~2 A top view of a semiconductor light emitting device according to the first embodiment of the present invention. Figure 3 for Figure 1 Schematic diagram of the partial structure of a semiconductor light-emitting element. Figure 4 for Figure 1 A cross-sectional view of a semiconductor light emitting element along line AA'.

[0031] In view of the technical problems of the above-mentioned existing semiconductor light-emitting components, the present invention proposes to improve the shape of the current blocking layer below the end of the first metal electrode extension strip, that is, for the design that the first metal electrode extension strip includes an extension section and an end, the strip-shaped portion of the current blocking layer located below part of the extension section has a gradually widening portion along the extension direction gradually away from the first metal electrode pad. This can improve the phenomenon of excessive concentration of charge distribution under electrostatic shock at the far end of the first metal electrode extension strip, and can avoid current crowding near the far end of the first metal electrode extension strip due to the offset of the current blocking layer position, improve ESD performance, and improve the reliability of the component.

[0032] Specifically, the semiconductor light emitting element of the present invention includes: a first conductive type semiconductor layer 102, a second conductive type semiconductor layer 104 and an active layer 103 between the first conductive type semiconductor layer 102 and the second conductive type semiconductor layer 104; a current blocking layer 105, a transparent electrode layer 106; a first metal electrode 107, including a first metal electrode pad 1071 and a first metal electrode extension strip extending from the first metal electrode pad 1071.

[0033] The first conductive type semiconductor layer 102, the second conductive type semiconductor layer 104 and the active layer 103 can be referred to as a semiconductor light emitting stack. The semiconductor light emitting stack is stacked on a substrate 100, and the substrate 100 can be selected from a gallium arsenide (GaAs) substrate 100 for growing gallium indium phosphide (AlGaInP), a sapphire (Al2O3) substrate 100, a gallium nitride (GaN) substrate 100, a silicon carbide (SiC) substrate 100, or an aluminum nitride (AlN) substrate 100 for growing indium gallium nitride (InGaN) or aluminum gallium nitride (AlGaN). The substrate 100 can be a patterned substrate 100, that is, an upper surface of the substrate 100 for epitaxially growing the semiconductor light emitting stack can include a patterned structure. The light emitted from the semiconductor light emitting stack can be refracted by the patterned structure of the substrate 100, thereby improving the brightness of the optoelectronic element.

[0034] In addition, the patterned structure mitigates or suppresses the dislocation caused by the lattice mismatch between the substrate 100 and the semiconductor light emitting stack, thereby improving the epitaxial quality of the semiconductor light emitting stack.

[0035] In one embodiment of the present invention, a semiconductor light emitting stack may be formed on the substrate 100 by metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor phase epitaxy (HVPE) or ion plating, such as sputtering or evaporation.

[0036] In an exemplary embodiment of the present invention, the first conductive type semiconductor layer 102 and the second conductive type semiconductor layer 104, such as a coating layer or a confining layer, have different conductivity types, electrical properties, polarities, or doping elements for providing electrons or holes. For example, the first conductive type semiconductor layer 102 is a p-type semiconductor, and the second conductive type semiconductor layer 104 is an n-type semiconductor. The active layer 103 is formed between the second conductive type semiconductor layer 104 and the first conductive type semiconductor layer 102. Under current drive, electrons and holes combine in the active layer 103 to convert electrical energy into light energy to emit light. The wavelength of light emitted by the semiconductor light emitting stack can be adjusted by changing the physical properties and chemical composition of one or more layers in the semiconductor light emitting stack.

[0037] The material of the semiconductor light emitting stack includes a III-V semiconductor material of AlxInyGa(1-xy)N or AlxInyGa(1-xy)P, wherein 0≤x, y≤1; (x+y)≤1. According to the material of the active layer 103, when the material of the semiconductor light emitting stack is AlInGaP series, red light with a wavelength between 610 and 650 nanometers or a red light with a wavelength between 550 and 570 nanometers can be emitted. rice When the material of the semiconductor light-emitting stack is InGaN series, it can emit blue light or deep blue light with a wavelength between 400 and 490 nanometers, or a yellow light with a wavelength between 490 and 550 nanometers. rice When the material of the semiconductor light emitting stack is AlGaN series, UV light with a wavelength between 220 and 400 nanometers can be emitted. The active layer 103 can be a single heterostructure (SH), a double heterostructure, a double-sided double heterostructure or a multiple quantum well. The material of the active layer 103 can be an i-type, p-type or n-type semiconductor.

[0038] Before forming the semiconductor light emitting stack, a buffer layer (not shown) may be formed on the upper surface of the substrate 100. The buffer layer may also reduce the above-mentioned lattice mismatch and suppress dislocation, thereby improving the epitaxial quality. The material of the buffer layer includes GaN, AlGaN or AlN.

[0039] A portion of the first conductive type semiconductor layer 102 and the active layer 103 is removed by an etching process until a portion of the upper surface of the second conductive type semiconductor layer 104 is exposed, thereby forming an exposed area. At the exposed area, the sidewalls of the first conductive type semiconductor layer 102 and the active layer 103 and a portion of the upper surface of the second conductive type semiconductor layer 104 are exposed.

[0040] The current blocking layer 105 has a strip-shaped portion, is formed on a local surface of the first conductive type semiconductor layer 102 and partially formed on a local surface of the second conductive type semiconductor layer 104, and is located under the first metal electrode 107 and under the second metal electrode 108. The current blocking layer 105 is similar in shape to the first metal electrode 107 and the second metal electrode 108. The current blocking layer 105 is used to block the current from being transmitted to or from the semiconductor light emitting stack in a vertical direction from the first metal electrode 107 and the second metal electrode 108.

[0041] The material of the current blocking layer 105 includes at least one of transparent inorganic insulating materials such as silicon oxide, silicon nitride, silicon oxynitride, titanium oxide or aluminum oxide. The current blocking layer 105 can also be a single layer or an alternating multilayer structure. The single layer can be a material with a high light transmittance, such as higher than 80%, such as silicon oxide. The current blocking layer 105 can also be a reflective material formed by a combination of multilayer structures, and the reflectivity is higher than 60%, such as a Bragg reflector. The thickness of the current blocking layer 105 can be selected from any thickness between 50 microns and 500 microns.

[0042] The transparent electrode layer 106 is located between the first metal electrode 107 and the current blocking layer 105, and is located on the surface of the first conductive type semiconductor layer 102 outside the first metal electrode 107. The transparent electrode layer 106 can form an ohmic contact with the first conductive type semiconductor layer 102. The transparent electrode layer 106 may include a light-transmitting and conductive material, such as a conductive oxide or a light-transmitting metal layer. In addition, the transparent electrode layer 106 may include at least one of ITO (indium tin oxide), ZnO (zinc oxide), ZITO (zinc indium tin oxide), ZIO (zinc indium oxide), ZTO (zinc tin oxide), GITO (gallium indium tin oxide), GIO (gallium indium oxide), GZO (gallium zinc oxide), AZO (aluminum-doped zinc oxide), and FTO (fluorine tin oxide).

[0043] The transparent electrode layer 106 has a high optical transmittance, for example, 60%, 70%, 75%, 80% or higher, to the light emitted by the active layer 103, and has high conductivity. The transparent electrode layer 106 covers an area of ​​at least 80% or further at least 90% above the surface of the first conductive type semiconductor layer 102.

[0044] The first metal electrode 107 is disposed on an upper surface of the first conductive type semiconductor layer 102 and is electrically connected to the first conductive type semiconductor layer 102 .

[0045] like Figure 1As shown, the first metal electrode 107 includes a first metal electrode pad 1071 and a first metal electrode extension strip extending from the first metal electrode pad 1071. The second metal electrode 108 includes a second metal electrode pad 1081 and a second metal electrode extension strip extending from the second metal electrode pad 1081. The first metal electrode pad 1071 and the second metal electrode pad 1081 are used for injecting or outputting external current, and the first metal electrode extension strip and the second metal electrode extension strip are used for horizontally diffusing the current.

[0046] The materials of the first metal electrode pad 1071, the first metal electrode extension strip, the second metal electrode pad 1081, and the second metal electrode extension strip are selected from metals such as gold (Au), silver (Ag), copper (Cu), chromium (Cr), aluminum (Al), platinum (Pt), nickel (Ni), titanium (Ti), tin (Sn), rhodium (Rh), etc., alloys or laminates of the above materials. More preferably, the first metal electrode pad 1071, the first metal electrode extension strip, the second metal electrode pad 1081, and the second metal electrode extension strip all have the same material composition and thickness.

[0047] like Figure 1 As shown, the semiconductor light emitting element is usually in a rectangular shape, and a few semiconductor light emitting elements are designed as squares. For a rectangular semiconductor light emitting element, including two relatively long sides and two relatively short sides, the first metal electrode pad 1071 and the second metal electrode pad 1081 are usually adjacent to the two relatively short sides, so that there is as large a distance as possible between the two. At least the main length portion of the first metal electrode extension strip and the second metal electrode extension strip extends toward the second metal electrode pad or the first metal electrode pad, respectively.

[0048] The first metal electrode pad 1071 and the second metal electrode pad 1081 are circular, elliptical, polygonal or irregular in shape. The width of the first metal electrode pad and the second metal electrode pad is much greater than the width of the metal expansion strip.

[0049] The width of the first metal electrode extension strip and the second metal electrode extension strip is in the range of 1-10 micrometers.

[0050] The first metal electrode extension strip includes an extension section and an end portion.

[0051] The entire extension section of the first metal electrode extension strip has a fixed width along the extension direction gradually away from the first metal electrode pad to the end; or the width first gradually decreases and then remains fixed to the end; or the width gradually decreases to the end.

[0052] The extension section may include a straight extension section, the straight extension section has a fixed extension direction, the straight extension section extends toward the second metal electrode pad, and the straight extension section is directly connected to the end portion.

[0053] Alternatively, the extension section may include an arc extension section, which is curved and has an unfixed radius of curvature or a fixed radius of curvature and an unfixed radius of curvature, wherein the extension direction of the arc extension section is roughly toward the first metal electrode pad, and the arc extension section is directly connected to the end.

[0054] Alternatively, the extension segment includes a combination of a straight extension segment and an arc extension segment, wherein the straight extension segment extends toward the second metal electrode pad; the arc extension segment extends from the straight extension segment and is further away from the first metal electrode pad and closer to the second metal electrode pad than the straight extension segment. The extension direction of the arc extension segment deviates from the extension direction of the straight extension segment, wherein the arc extension segment is directly connected to the end portion.

[0055] Or the extension segment includes a combination of a straight extension segment and a folded extension segment, wherein the straight extension segment extends toward the second metal electrode pad; the folded extension segment is farther away from the first metal electrode pad and closer to the second metal electrode pad than the straight extension segment. The folded extension segment extends from the straight extension segment, the folded extension segment is straight, has a fixed extension direction, deviates from the extension direction of the straight extension segment, and the folded extension segment is directly connected to the end.

[0056] The end of the first metal electrode extension strip is connected to the end of the extension section farthest from the first metal electrode pad. Relative to the width of the end of the extension section, the local width of the end is widened to be a semicircular arc, an ellipse or a polygon. The local widening of the end is beneficial to avoid charge concentration at the end, promote current dispersion, and improve ESD performance.

[0057] At the position connected to the first metal electrode pad 1071, the first metal electrode extension strip also includes a first metal electrode extension strip connecting portion 1072. The first metal electrode extension strip connecting portion 1072 serves as a width transition section between the first metal electrode pad and the extension section of the first metal electrode extension strip. The first metal electrode extension strip connecting portion 1072 gradually decreases in width in the direction away from the first metal electrode pad, thereby avoiding a large width difference between the first electrode extension strip and the first metal electrode pad, which may cause charge concentration and burns at the connection.

[0058] In this exemplary embodiment, Figure 1 As shown, the first metal electrode extension strip may specifically include a straight extension segment 1073, an arc extension segment 1074 and an end 1075. The extension direction of the straight extension segment 1073 of the first metal electrode extension strip is fixed, the arc extension segment 1074 is connected to the straight extension segment 1073, and the arc extension segment 1074 is farther away from the first metal electrode pad 1071 than the straight extension segment 1073.

[0059] One end of the straight line extension segment is directly connected to the first metal electrode extension strip connection portion 1072, the straight line extension segment 1073 extends in the direction of the second metal electrode pad 1081, and the other end has an arc extension segment 1074; the arc extension segment 1074 deviates from the extension direction of the straight line extension segment 1073, wherein the arc extension segment is a curved segment, that is, an arc shape with a fixed curvature radius or an unfixed curvature radius, and the arc extension segment 1074 can extend toward the corner where the two edges of the surface of the first conductive type semiconductor layer intersect near the second metal electrode pad 1081. As a result, the arc extension portion of the first metal electrode extension strip maintains a predetermined value of distance or a distance greater than the predetermined value from the second metal electrode pad 1081, which can avoid current crowding caused by the too short distance between a section near the end of the straight line extension segment and the second metal electrode pad 1081, which is beneficial to the current diffusion around the second metal electrode pad 1081. For example Figure 1 For the semiconductor light emitting element shown, the predetermined value is preferably at least 1 / 2 of the distance between the straight extension portion of the first metal extension strip and one side of the side closest to the second conductive type semiconductor layer, and at most 3 / 2.

[0060] like Figure 3 As shown, the straight extension segment 1073 and the arc extension segment 1074 of the first metal electrode extension strip may have width values ​​of W1 and W2 respectively along the extension direction gradually away from the first metal electrode pad 1071, and W1 and W2 are respectively fixed, and the values ​​of W1 and W2 are between 1 and 10 microns; or along the extension direction gradually away from the first metal electrode pad 1071, W1 first gradually decreases, and then maintains a fixed length to the end of the straight extension segment, and the value of W2 is fixed; or along the extension direction gradually away from the first metal electrode pad 1071, W1 gradually decreases to the end of the straight extension segment, and W2 gradually decreases from the end of the straight extension segment to the end 1075. The gradually decreasing distribution of the width of at least one of the straight extension segment 1073 and the arc extension segment 1074 can facilitate the lateral expansion of the current from both sides of the extension portion of the first metal electrode extension strip.

[0061] like Figure 2 As shown, the current blocking layer 105 specifically includes a first pad portion 1051 and a first strip portion below the first metal electrode 107. The first pad portion 1051 and the first strip portion are correspondingly and respectively formed below the first metal electrode pad 1071 and the first metal electrode extension strip, and are both located above the first conductive type semiconductor layer 102. The first pad portion 1051 and the first strip portion have a width that is greater than the width of the first metal electrode pad 1071 and the first metal electrode extension strip above them.

[0062] At the first metal electrode pad 1071, at least part of the current is blocked from flowing downward by the first pad portion 1051, and then the current diffuses outward through the first metal electrode extension strip and a transparent electrode layer 106. At the first metal electrode extension strip, the current is blocked from flowing downward by the first strip-shaped portion of the current blocking layer 105, and the current diffuses laterally in the transparent electrode layer 106, and then flows evenly into the first conductive type semiconductor layer 102.

[0063] In addition, the current blocking layer 105 may also include a second pad portion and a second strip portion formed under the second metal electrode pad 1081 and the second metal electrode extension strip, respectively. And under the second metal electrode extension strip, the current blocking layer 105 may also include a second strip portion and exist in a plurality of separated blocks. The plurality of separated blocks block at least part of the current diffused by the second metal electrode extension strip from flowing downward, and the current flows downward into the second conductive type semiconductor layer 104 through the second metal electrode extension strip between two adjacent blocks. In the area between any two adjacent and separated blocks, the second metal electrode extension strip contacts the second conductive type semiconductor layer 104, and a plurality of low contact resistance contact areas are formed between the second metal electrode extension strip and the second conductive type semiconductor layer 104, and the current can flow from the second metal electrode extension strip into the second conductive type semiconductor layer 104 through the low contact resistance contact areas.

[0064] The difference between the width of the first strip-shaped portion of the current blocking layer 105 and the width of the first metal electrode extension strip is not a fixed value, but a variable value. That is, the strip-shaped portion of the current blocking layer located above the extension section of the first metal electrode extension strip has a gradually widening portion along the extension direction gradually away from the first metal electrode pad. More specifically, a local widening portion is formed below the first metal extension strip of the current blocking layer, near the end away from the first metal electrode pad. By widening the coverage area of ​​the current blocking layer around the two side edges near the end of the first metal electrode extension strip, it is possible to avoid excessive concentration of partial charges near the end of the metal electrode extension strip, optimize the local electric field distribution effect, and avoid current crowding near the far end of the first metal electrode extension strip due to the offset from the current blocking layer position. In particular, for the case where there is an arc extension section or a broken line extension section near the end of the first metal electrode extension strip, the product's ability to resist high-order ESD impacts can be greatly improved, and the reliability of the semiconductor light-emitting element can be improved.

[0065] Specifically, Figure 2As shown, below the first metal electrode extension strip, the strip-shaped portion of the current blocking layer 105 includes a first length portion 1053, a second length portion 1054 and an end enlarged portion 1055, and the first length portion 1053 is closer to the first metal electrode pad 1071 than the second length portion 1054, wherein the second length portion 1054 is the widened portion.

[0066] In an exemplary embodiment, the first strip portion of the current blocking layer 105 includes a first length portion 1053 , a second length portion 1054 and an end enlarged portion 1055 , which are respectively located below a straight line extension segment 1073 , an arc extension segment 1074 and an end portion 1075 .

[0067] Or as an exemplary embodiment, Figure 3 As shown, the first strip portion of the current blocking layer 105 includes a first length portion 1053 correspondingly located below a straight line extension segment 1073, a second length portion 1054 correspondingly located below part of a straight line extension segment 1073 and below an arc extension segment 1074, and an end enlarged portion 1055 correspondingly located below the end portion 1075.

[0068] like Figure 3 As shown, below the first metal electrode, the first length portion 1053 of the current blocking layer 105 has a width W3, and the second length portion 1054 has a width W4; above the first length portion 1053 of the current blocking layer 105, the extension segment of the first metal electrode extension strip has a width W1; above the second length portion 1053 of the current blocking layer 105, the straight extension segment of the first metal electrode extension strip has a width W1, and the curved extension segment has a width W2.

[0069] Preferably, the values ​​of W1 and W2 are between 1 and 10 microns.

[0070] Preferably, W3 is between 5 and 21 microns.

[0071] The difference between the width W3 of the first strip portion 1053 of the current blocking layer 105 and the width W1 of the first metal electrode extension strip extension segment directly above it is D1, D1 is greater than 0 microns, and regardless of whether the width W1 of the first metal electrode extension strip extension segment directly above the first strip portion 1053 is fixed or variable, D1 is fixed for the entire first strip portion 1053 of the current blocking layer. Preferably, D1 is at least 5 microns and at most 20 microns. Too large a D1 value will cause a voltage increase.

[0072] The second length portion 1054 of the current blocking layer 105 has a width W4 at the widest point, W4 is greater than W3, preferably, W4 is at least 10 microns and at most 40 microns. The difference between the width W4 at the widest point of the second length portion 1054 of the current blocking layer 105 and the width W1 or W2 of the first metal electrode extension strip extension segment directly above it is defined as D2, and the D2 value is preferably between 5 and 30 microns.

[0073] Preferably, the difference between D2 and D1 is at least 1 micron, more preferably 5 to 25 microns.

[0074] like Figure 3 As shown, along the entire length range of the second length portion of the current blocking layer 105, the width of the second length portion of the current blocking layer 105 first gradually increases and then maintains a maximum value W4 unchanged.

[0075] The current blocking layer 105 further has a strip-shaped partial connecting portion 1051 located below the connecting portion 1071 of the first metal electrode extension strip, and the difference in width between the two is also the value D1.

[0076] More preferably, the widened portion of the current blocking layer is simultaneously located below the end of the first metal electrode extension strip, that is, the width difference between the end of the widened portion of the current blocking layer and the end of the first metal electrode extension strip is greater than D1.

[0077] As a specific embodiment of this embodiment, the values ​​of W1 and W2 are both fixed values ​​of 2.5 microns, W3 is 8.5 microns, and W4 is 14.5 microns.

[0078] In this exemplary embodiment, Figures 1 to 4As shown, the current blocking layer 105 has a first pad portion 1051 located below the first metal electrode pad 1071. The first pad portion 1051 and the first metal electrode pad 1071 have substantially the same shape, which is a block or a ring. The outer diameter width of the first pad portion 1051 is greater than the width of the first metal electrode pad 1071. The transparent electrode layer 106 extends below the first metal electrode pad 1071 to cover a portion of the upper surface of the first pad portion 1051. The transparent electrode layer 106 includes an opening 1061 located below the first metal electrode pad 1071. 071, the width of the opening 1061 is smaller than the width of the first metal electrode pad 1071, and the opening 1061 exposes a portion of the upper surface of the first pad portion 1051 of the current blocking layer 105, the first metal electrode pad 1071 covers the first pad portion 1051 of the current blocking layer below the opening area of ​​the transparent electrode layer 106, and the first metal electrode pad 1071 also covers a portion of the surface of the transparent electrode layer 106 around the opening area, and the first metal electrode extension strip of the first metal electrode 107 is located above the transparent electrode layer 106.

[0079] The first metal electrode pad 1071 of the first metal electrode 107 may not directly contact the first conductive type semiconductor layer 102, and the first metal electrode extension strip of the first metal electrode 107 is located above the transparent electrode layer 106, so the current can be transferred to the transparent electrode layer 106 through the first metal electrode extension strip and then diffused more effectively.

[0080] Optionally, below the first metal electrode pad 1071, the first pad portion 1051 of the current blocking layer 105 may also have a plurality of independent blocks and have a gap, allowing a portion of the surface of the first metal electrode pad 1071 to contact the first conductive type semiconductor layer 102. Alternatively, below the first metal electrode pad 1071, the first pad portion 1051 of the current blocking layer 105 may also have an annular opening, and at least one independent block-shaped portion of the current blocking layer 105 is also provided in the annular opening.

[0081] In addition, if Figure 5As shown, the surfaces of the first metal electrode and the second metal electrode of the semiconductor light-emitting element may also include a transparent protective layer 109, and the transparent protective layer 109 may be selected from at least one transparent inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, titanium oxide or aluminum oxide. The transparent protective layer 109 may be a material with a high light transmittance, for example, higher than 80%, such as silicon oxide. The transparent protective layer 109 may also be a reflective material formed by a combination of multiple layers, and a material with a reflectivity higher than 60%, such as a Bragg reflector. The thickness of the transparent protective layer 109 ranges from 50 microns to 500 microns. The transparent protective layer 109 at least covers the exposed side walls of the semiconductor light-emitting stack, the transparent electrode layer, the side walls of the first metal electrode, and the portion of the first metal electrode away from the surface of the semiconductor light-emitting element, and is used to isolate and protect the various regions of the semiconductor light-emitting element from water vapor.

[0082] According to the existing technology, Fig.12 The semiconductor light emitting element shown in FIG. 1 is a conventional design having a semiconductor light emitting element structure with a fixed width difference between the first metal electrode extension strip and the strip-shaped portion of the current blocking layer, and the semiconductor light emitting element structure obtained by improving according to this embodiment. Figure 1 The semiconductor light emitting element shown in the figure is an optimized design, that is, some strip-shaped portions of the current blocking layer have widened portions, and the ESD performance is compared, and the results are as follows: Figure 6 The data graph is shown. The peak emission bands of the semiconductor light-emitting elements are all blue light bands, and the ESD performance is tested under a forward voltage of 200V. It can be seen that the ESD yield of the semiconductor light-emitting element of the present invention is significantly improved. By changing the graphic design of the local current blocking layer of the first metal electrode extension strip, the local electric field distribution effect is optimized, and the ESD impact resistance capability is greatly improved.

[0083] The back side of the substrate of the semiconductor light emitting element (ie, the side opposite to the semiconductor light emitting stack) may be coated with a reflective layer, such as a metal reflective layer or a Bragg reflective layer, to facilitate light emission from the front and / or side of the semiconductor light emitting stack.

[0084] The semiconductor light-emitting element of the present invention can be further sealed to form a package, including a package support supporting the semiconductor light-emitting element, such as a bowl-shaped resin substrate or a flat ceramic substrate; the light-emitting surface of the semiconductor light-emitting element can be further sealed with a sealing resin, such as a transparent resin or a resin further containing phosphor, to provide luminous radiation such as blue light, green light, red light or white light.

[0085] The package of the present invention can be further made into a light-emitting device, such as a white light lighting device, a backlight display device, an RGB display device, a car light, a flash light, a projection light, a stage light, an ultraviolet sterilizer or a filament lamp.

[0086] For the semiconductor light-emitting element of the present invention, the shape of the current blocking layer below the extension section of the first metal electrode extension strip near the end is improved, that is, the current blocking layer has a gradually widened widening portion along the extension direction gradually away from the first metal electrode pad, and a wider alignment window is reserved for the part near the end of the first metal electrode extension strip, thereby changing the phenomenon of excessive concentration of charge distribution under electrostatic shock at the far end of the first metal electrode extension strip, and avoiding current crowding near the far end of the first metal electrode extension strip due to position offset with the current blocking layer, improving ESD performance, and improving the reliability of the electrode structure. It is particularly suitable for solving the current crowding problem caused by more serious alignment offset between the arc extension section and the current blocking layer near the far end of the first metal electrode extension strip.

[0087] Embodiment 2

[0088] like Figure 7-8 As shown, this example provides a semiconductor light-emitting element with another electrode shape, which is different from the semiconductor light-emitting element of the first embodiment, wherein the curved extension portion replaces the outer fold line extension portion 1074', and the fold line extension portion 1074' extends away from the straight line extension portion 1073 and is a straight line with a fixed extension direction.

[0089] In one exemplary embodiment, the first strip portion of the current blocking layer 105 includes a first length portion 1053, a second length portion 1054 and an end enlarged portion 1055, which are respectively located below a straight line extension segment 1073, an arc extension segment 1074 and an end portion 1075.

[0090] Or as an exemplary embodiment, Figure 8 As shown, the first strip portion of the current blocking layer 105 includes a first length portion 1053 correspondingly located below a straight line extension segment 1073, a second length portion 1054 correspondingly located below part of a straight line extension segment 1073 and below a folded line extension segment 1074', and an end enlarged portion 1055 correspondingly located below the end portion 1075.

[0091] The linear extension of the first metal electrode extension strip maintains a distance greater than a predetermined value from the second metal electrode pad 1081, which can avoid current crowding caused by a too short distance between a section near the end of the linear extension and the second metal electrode pad 1081, and is conducive to current diffusion around the second metal electrode pad 1081. Figure 7 For the semiconductor light emitting element shown, the predetermined value is preferably at least 1 / 2 of the distance between the straight extension portion of the first metal extension strip and one side edge thereof adjacent to the second conductive type semiconductor layer, and at most 3 / 2.

[0092] Embodiment 3

[0093] This embodiment provides a semiconductor light-emitting element with another electrode shape, which is different from the semiconductor light-emitting element of the first embodiment, and the number of first metal electrode extension strips included in the first metal electrode can be more than two. At least two of the first metal electrode extension strips include a straight line extension segment, an arc extension segment (or a folded line extension segment) and an end in the direction gradually approaching the second metal electrode pad. One end of the straight line extension segment is connected to an arc extension segment or a folded line extension segment; the arc extension segment or the folded line extension segment deviates from the extension direction of the straight line extension segment, the arc extension segment is a curved segment, and has an arc shape with a fixed or non-fixed radius of curvature, and the folded line extension segment is a straight line extension segment with a fixed extension direction.

[0094] Specifically, Fig. 9 The schematic diagram of the semiconductor light emitting element of this embodiment shown in FIG. 1 includes a first metal electrode 107, Fig.10 shown Fig. 9 A partial enlarged schematic diagram of the first metal electrode extension strip portion within the circle indicated by position A in the middle. The first metal electrode includes three first metal electrode extension strips, two of which are closer to the edges of the two parallel sides of the semiconductor light-emitting stack, and one first metal electrode extension strip is located in the middle of the surface of the semiconductor light-emitting stack. The two first metal electrode extension strips close to the edge of the semiconductor light-emitting stack have a straight extension section 1073, an arc extension section 1074 and an end 1075 respectively.

[0095] Specifically, below the first metal electrode extension strip, the strip-shaped portion of the current blocking layer 105 includes a first length portion 1053, a second length portion 1054 and an end enlarged portion 1055, and compared with the second length portion 1054, the first length portion 1053 is closer to the first metal electrode pad 1071, wherein the second length portion 1054 is the widened portion.

[0096] The strip portion of the current blocking layer 105 includes a first length portion 1053 correspondingly located below a straight line extension segment 1073 , a second length portion 1054 correspondingly located below part of the straight line extension segment 1073 and below the arc extension segment 1074 , and an end enlarged portion 1055 correspondingly located below an end portion 1075 .

[0097] In addition, if Fig. 9In the light-emitting element shown, one end of a straight extension segment of the first metal electrode extension strip is not directly connected to the first metal electrode pad, and the first metal electrode extension strip has a metal electrode extension strip connecting portion between the metal electrode pad and the straight extension segment, and the metal electrode extension strip connecting portion has a width that gradually narrows in a direction away from the metal electrode pad.

[0098] Embodiment 4

[0099] This embodiment provides a semiconductor light emitting element with another electrode shape, which is different from the semiconductor light emitting element of the first embodiment, wherein a first metal electrode extension strip has a straight extension segment (arc extension segment) and an end, wherein the straight extension segment (or arc extension segment) extends toward the second metal electrode pad, and the straight extension segment (arc extension segment) is directly connected to the end. Specifically, Fig. 9 In the semiconductor light emitting element shown, the first metal electrode extension strip located in the middle of the semiconductor light emitting stack has a straight line extension section and an end portion, wherein the straight line extension section and the end portion are directly connected. Fig.11 Provided Fig. 9 A partial enlarged schematic diagram of the vicinity of the end of the middle first metal electrode extension strip at the position marked with circle B. Fig.11 As shown, the middle first metal electrode extension strip has a straight extension section 1073 and an end 1075 .

[0100] Below the first metal electrode extension strip located in the middle, the strip-shaped portion of the current blocking layer 105 includes a first length portion 1053, a second length portion 1054 and an end enlarged portion 1055, and the first length portion 1053 is closer to the first metal electrode pad 1071 than the second length portion 1054, wherein the second length portion 1054 is the widened portion, and the difference between the width of the first length portion 1053 and the width of the first metal electrode extension strip is D1, and the difference between the width of the second length portion and the width of the first metal electrode extension strip is D2, and D1 is smaller than D2.

[0101] The width difference D1 between the first length portion 1053 of the strip portion of the current blocking layer 105 and the first metal electrode extension strip directly above it is fixed. Preferably, D1 is 5-20 microns.

[0102] like Fig.11 As shown, the strip portion of the current blocking layer 105 includes a first length portion 1053 and a second length portion 1054 which are correspondingly located under different portions of a straight line extension segment 1073 , and an end enlarged portion 1055 which is correspondingly located under an end portion 1075 .

[0103] The second length portion of the first strip-shaped portion of the current blocking layer 105 is a widened portion, which gradually widens from the end of the first length portion and reaches a maximum width value. The difference between the maximum width value and the width of the first metal electrode extension strip directly above it is greater than D1, and has a maximum value of D2. Preferably, the difference between the maximum value of D2 and D1 is at least 1 micron and at most 25 microns.

[0104] Preferably, the length of the first metal electrode extension strip above the second length portion of the current blocking layer is at least 1 / 10 and at most 1 / 4 of the entire length of the first metal electrode extension strip from the second electrode pad.

[0105] This embodiment improves the shape of the current blocking layer below the straight extension section of the first metal electrode extension strip near the end portion, that is, the current blocking layer has a gradually widening portion along the extension direction gradually away from the first metal electrode pad, thereby improving the phenomenon of excessive concentration of charge distribution under electrostatic shock at the far end of the first metal electrode extension strip, and avoiding current crowding near the far end of the first metal electrode extension strip due to the offset of the position of the current blocking layer, thereby improving ESD performance and improving the reliability of the electrode structure.

[0106] Although the present invention has been illustrated with reference to some embodiments in conjunction with the accompanying drawings, it will be apparent to those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention. In addition, it should be understood that some features of a particular embodiment may also be applied to other embodiments without departing from the spirit and scope of the present invention. Therefore, it should be understood that the embodiments are provided only by way of example, and embodiments are given to provide a complete disclosure of the present invention, and to provide a thorough understanding of the present invention to those skilled in the art. Therefore, it is intended that the present invention covers modifications and changes as long as they fall within the scope of the claims and their equivalents.

Claims

1. A semiconductor light emitting element, comprising: A first conductivity type semiconductor layer, a second conductivity type semiconductor layer and an active layer therebetween; a current blocking layer, comprising a strip-shaped portion, disposed on a partial surface of the first conductive type semiconductor layer; A first metal electrode, comprising a first metal electrode pad and a first metal electrode extension strip extending from the first metal electrode pad, wherein the first metal electrode extension strip is located on the strip-shaped portion of the current blocking layer; It is characterized in that: the first metal electrode extension strip includes an extension section and an end; the strip portion of the current blocking layer located below part of the extension section has a gradually widening portion along the extension direction gradually away from the first metal electrode pad.

2. A semiconductor light emitting element according to claim 1, characterized in that: Below the extension section of the first metal electrode extension strip, the strip-shaped portion of the current blocking layer includes a first length portion and a second length portion, the first length portion being closer to the first metal electrode pad than the second length portion, and the second length portion being the widened portion; the difference between the width of the first length portion and the width of the extension section of the first metal electrode extension strip directly above it is D1, the difference between the width of the widest part of the second length portion and the width of the first metal electrode extension extension section strip directly above it is D2, D1 is less than D2, D1 is greater than 0 microns, and D2 is greater than 0 microns.

3. The semiconductor light emitting element according to claim 2, characterized in that: The width difference D1 between the first length portion of the strip-shaped portion of the current blocking layer and the extension segment of the first metal electrode extension strip directly above it is fixed and unchanged.

4. The semiconductor light emitting element according to claim 2, characterized in that: The D1 value is at least 5 microns and at most 20 microns.

5. The semiconductor light emitting element according to claim 2 or 3, characterized in that: The width difference D2 between the second length portion of the strip portion of the current blocking layer and the first metal electrode extension strip extension portion directly above it gradually increases in a direction away from the first metal electrode pad or first increases gradually and then remains constant.

6. The semiconductor light emitting element according to claim 5, characterized in that: The D2 has a maximum value, and the difference between the maximum value of D2 and D1 is at least 1 micron.

7. The semiconductor light emitting element according to claim 2, characterized in that: The entire extension section of the first metal electrode extension strip extends in a direction gradually away from the first metal electrode pad, and its width remains fixed to the end, or its width gradually decreases and then remains fixed to the end, or its width gradually decreases to the end.

8. The semiconductor light emitting element according to claim 1 or 2, characterized in that: The first metal electrode extension strip includes a straight extension section and an end portion, wherein the straight extension section and the end portion are directly connected.

9. The semiconductor light emitting element according to claim 1 or 2, characterized in that: The first metal electrode extension strip includes an arc extension section and an end portion, wherein the arc extension section and the end portion are directly connected.

10. The semiconductor light emitting element according to claim 8, characterized in that: The widened portion of the current blocking layer is located below a portion of the straight extension section of the first metal electrode extension strip.

11. The semiconductor light emitting element according to claim 9, characterized in that: The widened portion of the current blocking layer is located below a portion of the arc extension section of the first metal electrode extension strip.

12. The semiconductor light emitting element according to claim 1, characterized in that: The widened portion of the current blocking layer is also located below the end of the first metal electrode extension strip.

13. The semiconductor light emitting device according to claim 1, characterized in that: The first metal electrode extension strip includes a straight extension segment, an arc extension segment and an end, or the first metal electrode extension strip includes a straight extension segment, a folded line extension segment and an end; the arc extension segment and the folded line extension segment are directly connected to the straight extension segment, the arc extension segment and the folded line extension segment are farther away from the first metal electrode pad than the straight extension segment, and the extension direction of the arc extension segment and the folded line extension segment deviates from the extension direction of the straight extension segment.

14. The semiconductor light emitting element according to claim 13, characterized in that: The strip-shaped widened portion of the current blocking layer is at least below the arc extension section or the fold line extension section.

15. The semiconductor light emitting element according to claim 14, characterized in that: The strip-shaped partially widened portion of the current blocking layer is simultaneously below the partially straight line extension segment and below the entire arc extension segment or the broken line extension segment.

16. The semiconductor light emitting element according to claim 13, characterized in that At least one of the straight extension segment and the arc extension segment of the first metal electrode extension strip has a fixed width or a width that first gradually decreases and then remains fixed, or a width that gradually decreases, along the extension direction gradually away from the first metal electrode pad.

17. The semiconductor light emitting element according to claim 13, characterized in that: The widened portion of the current blocking layer is also located below a portion of the straight extension segment.

18. The semiconductor light emitting element according to claim 13, characterized in that: The arc extension section and the broken line extension section are respectively in the shape of a curve and a straight line.

19. The semiconductor light emitting element according to claim 1, characterized in that The end is in the shape of a semicircle, an ellipse or a polygon.

20. The semiconductor light emitting device according to claim 1, characterized in that: The end of the first metal electrode extension strip is wider than the end of the extension section.

21. The semiconductor light emitting element according to claim 1, characterized in that The current blocking layer is a transparent insulating layer.

22. The semiconductor light emitting element according to claim 1, characterized in that The strip-shaped portion of the current blocking layer is a continuous film layer below the first metal electrode extension strip.

23. The semiconductor light emitting element according to claim 1, characterized in that The width of the first metal electrode extension strip is between 1 and 10 microns.

24. The semiconductor light emitting element according to claim 1, characterized in that The invention also includes a transparent electrode layer, which is disposed on the surface of the first conductive type semiconductor layer and at least partially covers the current blocking layer.

25. The semiconductor light emitting element according to claim 24, characterized in that The transparent electrode layer is metal oxide.

26. A light emitting device, comprising: A semiconductor light emitting element as claimed in any one of claims 1 to 25.

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