TWI825465B - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a substrate with a first surface and a second surface opposite to the first surface; and a first light-emitting unit located on the first surface of the substrate, including a first semiconductor layer and a semiconductor mesa located on the first semiconductor layer, wherein in a top view of the light-emitting device, the first semiconductor layer includes a first side and a first protrusion protruding from the first side, and the semiconductor mesa includes a second side and a second recess recessed from the second side and opposite to the first protrusion.

Description

Light emitting element

The present invention relates to a light-emitting element, and in particular to a light-emitting element including a plurality of light-emitting units.

Light-Emitting Diode (LED) is a solid-state semiconductor light-emitting element. Its advantages are low power consumption, low heat energy generation, long working life, shockproof, small size, fast response speed and good optoelectronic properties, such as Stable luminescence wavelength. Therefore, light-emitting diodes are widely used in household appliances, equipment indicators, and optoelectronic products.

According to an embodiment of the present invention, a light-emitting element is disclosed, which includes a substrate having a first surface and a second surface opposite to the first surface; and a first light-emitting unit is located on the first surface of the substrate and includes a first The semiconductor layer and a semiconductor mesa are located on the first semiconductor layer. Viewed from a top view of one of the self-luminous elements, the first semiconductor layer includes a first side and a first protrusion protruding from the first side. The semiconductor mesa includes A second side and a second concave portion are recessed in the second side and opposite to the first convex portion.

In order to make the description of the present invention more detailed and complete, please refer to the description of the following embodiments and the relevant illustrations. However, the embodiments shown below are used to illustrate the light-emitting element of the present invention, and the present invention is not limited to the following embodiments. In addition, the size, material, shape, relative arrangement, etc. of the constituent parts described in the embodiments described in this specification are not described as limiting, and the scope of the present invention is not limited thereto, but is merely explained. In addition, the size and positional relationship of components shown in each diagram may be exaggerated for clear explanation. Moreover, in the following description, in order to omit detailed explanation appropriately, components of the same or similar nature are shown with the same names and symbols.

Figure 1 is a top view of a light-emitting element 1 disclosed in an embodiment of the present invention. Figure 2 is a cross-sectional view of the light-emitting element 1 taken along the tangent line Y-Y' in Figure 1. Figure 3 is a partially enlarged view of position I of Figure 1. Figure 4 is a top view of a light-emitting element 2 disclosed in an embodiment of the present invention. Figure 5 is a cross-sectional view of the light-emitting element 2 taken along the tangent line Y-Y' in Figure 4. Figure 6 is a partially enlarged view of position II of Figure 4.

The light-emitting element 1 or 2 may be a small light-emitting diode chip with a small horizontal area, and at least any side has a length less than or equal to 200 μm but greater than 80 μm. For example, it has dimensions of 230 μm×180 μm or 150 μm×90 μm. However, the horizontal length and vertical length of the light-emitting element 1 or 2 of the embodiment are not limited to the above contents. Furthermore, the light-emitting element 1 or 2 may be a small-sized light-emitting diode chip with a thin thickness. The light-emitting element 1 or 2 may have a thickness of about 100 μm or less, and preferably has a thickness of about 40 μm or more and 90 μm or less. The light-emitting element 1 or 2 can be driven at a current density of 7 mA/mm ² or more and 250 mA/mm ² or less. The light-emitting element 1 or 2 of this embodiment can be applied to various small or thin light-emitting devices.

As shown in Figures 1 to 2 and Figures 4 to 5, the light-emitting element 1 or 2 includes a substrate 10. The substrate 10 has a first surface 100 and a second surface 110 opposite to the first surface 100 . A plurality of light-emitting units 1a, 1b are formed on the first surface 100 of the substrate 10 and are separated from each other by a trench 1000. Although the embodiment of the present invention is illustrated with two light-emitting units 1a and 1b, the number of light-emitting units included in the light-emitting element 1 or 2 of the present invention is not limited to two.

As shown in Figures 1 and 4, the trench 1000 separates the light-emitting units 1a and 1b from each other. Accordingly, the first surface 100 of the substrate 10 is exposed to the trench 1000 . The trench 1000 can be formed through photolithography and etching processes. The light-emitting units 1a and 1b face each other across the trench 1000. As shown in Figure 2 or Figure 5, the first light-emitting unit 1b and the second light-emitting unit 1a respectively include a semiconductor stack 20b, 20a. The semiconductor stacks 20b, 20a each include a first semiconductor layer 21b, 21a, a second semiconductor layer 22a, 22b, and an active layer 23a, 23b, wherein the active layers 23a, 23b are respectively located on the first semiconductor layer 21a, 21b. and between the second semiconductor layers 22a and 22b. The side surfaces of the light-emitting units 1a and 1b facing each other are defined as inner side surfaces, and the other side surfaces are defined as outer side surfaces. The first semiconductor layer 21b of the first light-emitting unit 1b and the first semiconductor layer 21a of the second light-emitting unit 1a also include an inner side and an outer side respectively. For example, the first semiconductor layers 21a and 21b respectively include one inner side surface 20a1 and 20b1 and three outer side surfaces 20a2 and 20b2. As shown in FIG. 2 or FIG. 5 , the outer side surfaces 20a2 and 20b2 and the inner side surfaces 20a1 and 20b1 of the first semiconductor layers 21a and 21b may be inclined. However, the present invention is not limited to this. Only the inner side surfaces 20a1 and 20b1 adjacent to the trench 1000 may be relatively inclined, and the outer side surfaces 20a2 and 20b2 may be aligned with the side surface 10s of the substrate 10 . For example, the outer side surfaces 20a2 and 20b2 of the first semiconductor layers 21a and 21b may be formed by scribing together with the substrate 10. Compared with the inner side surfaces 20a1 and 20b1, the outer side surfaces 20a2 and 20b2 are steeper, for example, they are vertical surfaces perpendicular to the first surface 100 of the substrate 10.

As shown in FIG. 1 or 4 , the first surface 100 of the substrate 10 is exposed around the first light-emitting unit 1 b and the second light-emitting unit 1 a. The exposed area around the first light-emitting unit 1b and the second light-emitting unit 1a is called an isolation area ISO. The light-emitting element 1 or 2 has a first side 11 and a second side 12 connected to the first side 11 . Figure 7 is a partial top view of position III in Figure 1 or position III in Figure 4. As shown in Figure 7, the separation area ISO has a first distance d1 on the first side 11, the separation area ISO has a second distance d2 on the second side 12, and the first distance d1 and the second distance d2 have Different widths. The first distance d1 and the second distance d2 include a width between 1 μm and 50 μm, preferably less than 30 μm, and more preferably less than 15 μm. In one embodiment, the first distance d1 includes a width between 1 μm and 30 μm, preferably between 3 μm and 20 μm, and more preferably between 5 μm and 15 μm. The second distance d2 includes a width between 0.5 μm and 20 μm, preferably between 2 μm and 12 μm, and more preferably between 3 μm and 9 μm.

As shown in FIG. 2 or FIG. 5 , the edge portions of the semiconductor stacks 20 a and 20 b are etched by dry etching or wet etching to expose the first semiconductor layers 21 a and 21 b. The remaining portions after etching constitute semiconductor mesas 20ma and 20mb, which are disposed on the first semiconductor layers 21a and 21b. The semiconductor mesas 20ma, 20mb may be defined on the inside surrounded by the first semiconductor layers 21a, 21b. The semiconductor mesas 20ma, 20mb include second semiconductor layers 22a, 22b, and active layers 23a, 23b, where the active layers 23a, 23b are respectively located between the first semiconductor layers 21a, 21b and the second semiconductor layers 22a, 22b.

The semiconductor mesa 20ma may include a through hole 200 penetrating the second semiconductor layer 22a and the active layer 23a. As shown in FIG. 1 , a plurality of through holes 200 may be formed on the semiconductor mesa 20ma, but a single through hole 200 may also be formed as shown in FIG. 4 . In a top view, the through hole 200 may be elongated, oval, or circular.

As shown in Figure 1 or Figure 4, the first semiconductor layers 21b and 21a located on the first light-emitting unit 1b and the second light-emitting unit 1a have complementary shapes in a top view. Specifically, the first semiconductor layer 21b on the first light-emitting unit 1b may be formed with a first protrusion 210b extending outside the first light-emitting unit 1b, and the first semiconductor layer 21a on the second light-emitting unit 1a may be formed correspondingly. There is a first recess 210a extending into the second light emitting unit 1a.

The semiconductor mesa 20mb on the first light-emitting unit 1b and the semiconductor mesa 20ma on the second light-emitting unit 1a may each be formed with a second recess 220b and a third recess 220a extending toward the inside of the semiconductor mesa 20mb, 20ma. The first semiconductor layers 21b and 21a are exposed through the second recessed portion 220b and the third recessed portion 220a. The second recessed portion 220b and the third recessed portion 220a are respectively formed to extend into the inside of the semiconductor mesa 20mb, 20ma of the first light-emitting unit 1b and the second light-emitting unit 1a. Specifically, as shown in FIG. 1 or 4, The second recessed portion 220b and the third recessed portion 220a may extend from one side m1, m1' of the semiconductor mesa 20mb, 20ma toward the other opposite side m2, m2'. The number of the second recessed portion 220b and the third recessed portion 220a may be one, or two or more (inclusive). The number of the first convex portions 210b provided on the first light-emitting unit 1b is the same as the number of the second recessed portions 220b provided on the first light-emitting unit 1b. The number of the second recessed portions 220b provided in the first light-emitting unit 1b is the same as the number of the third recessed portions 220a provided in the second light-emitting unit 1a.

In this embodiment, from the top view of the light-emitting element 1 or 2, as shown in Figure 1 or Figure 4, in the direction parallel to the first side 11 of the light-emitting element 1 or 2, it is disposed on the second The first recessed portion 210a and/or the third recessed portion 220a of the light-emitting unit 1a respectively have a maximum width greater than the maximum width of the second recessed portion 220b provided in the first light-emitting unit 1b. In a direction parallel to the second side 12 of the light-emitting element 1 or 2, the second recessed portion 220b provided in the first light-emitting unit 1b or the third recessed portion 220a provided in the second light-emitting unit 1a has a recessed depth no greater than its respective depth. the maximum width. In one embodiment, the recessed depth of the second recessed portion 220b is greater than the recessed depth of the third recessed portion 220a.

Figure 3 is a partially enlarged view of position I of Figure 1. Figure 6 is a partially enlarged view of position II of Figure 4. As shown in Figure 3 or Figure 6, the first semiconductor layer 21b of the first light-emitting unit 1b includes a first side 211b, and the first convex portion 210b protrudes in a direction toward the outside of the first light-emitting unit 1b. on the first side 211b. The first convex portion 210b means that the imaginary line between the two endpoints of the first convex portion 210b is located inside the first semiconductor layer 21b. The semiconductor mesa 20mb on the first light-emitting unit 1b includes a second side 222b, and a second recess 220b is recessed in the second side 222b in a direction toward the inside of the first light-emitting unit 1b. The second recessed portion 220b means that the imaginary line between the two endpoints of the second recessed portion 220b is located outside the semiconductor mesa 20mb. In a top view, the first convex portion 210b has a shape protruding out of the first side 211b of the first light-emitting unit 1b, and the position of the first convex portion 210b of the first semiconductor layer 21b corresponds to the second concave portion of the semiconductor mesa 20mb. 220b. In other words, the extending directions of the first convex portion 210b of the first semiconductor layer 21b of the first light-emitting unit 1b and the second recessed portion 220b of the semiconductor mesa 20mb are opposite. In order to achieve a better current dispersion effect for the first electrode 51b formed in the subsequent process, the first convex portion 210b includes a first curvature radius larger than a second curvature radius of the second concave portion 220b.

As shown in FIG. 3 or FIG. 6 , the first semiconductor layer 21a of the second light emitting unit 1a has a first recess 210a extending inward. The shape of the first concave portion 210a of the second light-emitting unit 1a is complementary to the shape of the first convex portion 210b on the first light-emitting unit 1b, and the position and shape of the third concave portion 220a of the semiconductor mesa 20ma correspond to the first semiconductor layer 21a The position and shape of the first recess 210a.

Specifically, the first semiconductor layer 21a on the second light-emitting unit 1a includes a first side 211a and a first recess 210a. In the direction toward the inside of the second light-emitting unit 1a, the first recessed portion 210a is recessed in the first side 211a and is opposite to the first convex portion 210b on the first light-emitting unit 1b. The semiconductor mesa 20ma on the second light-emitting unit 1a includes a second side 222a, and a third recessed portion 220a is recessed in the second side 222a and faces the first convex portion 210b on the first light-emitting unit 1b.

The positions of the third recessed portion 220a and the second recessed portion 220b of the semiconductor mesas 20ma and 20mb of the two adjacent light-emitting units 1a and 1b correspond to each other. As the number of the first convex portions 210b and the second recessed portions 220b increases, the number of the first electrodes 51b formed on the first convex portions 210b in subsequent processes also increases, thereby improving the current dispersion performance. Figure 1 illustrates that the first light-emitting unit 1b includes two first convex portions 210b and the second light-emitting unit 1a includes two first concave portions 210a. Figure 4 illustrates that the first light-emitting unit 1b includes a first convex portion 210b and the second light-emitting unit 1a includes a first concave portion 210a.

The part of the light-emitting element 1 illustrated in Figure 3 is generally similar to the part of the light-emitting element 2 illustrated in Figure 6. The main difference lies in the first side 211b of the first semiconductor layer 21b of the first light-emitting unit 1b of the light-emitting element 1. The distance between the first side edges 211a of the first semiconductor layer 21b of the second light-emitting unit 1a is substantially the same as the distance between the first convex part 210b and the first recessed part 210a, so that the trench 1000 of the light-emitting element 1 is in a top view. Have equally spaced width S. As shown in Figure 6, the distance between the first side 211b of the first semiconductor layer 21b of the first light-emitting unit 1b of the light-emitting element 2 and the first side 211a of the first semiconductor layer 21a of the second light-emitting unit 1a The distance between the first convex part 210b and the first recessed part 210a is different, so that the trench 1000 of the light-emitting element 2 has widths S1 and S2 with different distances in a top view. Specifically, there is a first distance S1 between the first convex portion 210b of the first light-emitting unit 1b and the first concave portion 210a of the second light-emitting unit 1a of the light-emitting element 2. There is a second spacing S2 between the first side 211b of the first semiconductor layer 21b of the first light-emitting unit 1b of the light-emitting element 2 and the first side 211a of the first semiconductor layer 21a of the second light-emitting unit 1a. In this embodiment, the first distance S1 may be larger or smaller than the second distance S2.

The substrate 10 may be a growth substrate for epitaxially growing the semiconductor stacks 20a, 20b. The substrate 10 includes a gallium arsenide (GaAs) wafer for epitaxial growth of aluminum gallium indium phosphide (AlGaInP), or for the growth of gallium nitride (GaN), indium gallium nitride (InGaN), or aluminum gallium nitride. (AlGaN) sapphire (Al ₂ O ₃ ) wafer, gallium nitride (GaN) wafer, silicon carbide (SiC) wafer, or aluminum nitride (AlN) wafer.

The first surface 100 of the substrate 10 connecting the semiconductor stacks 20a, 20b may be a roughened surface. The roughened surface may be a surface with irregular morphology or a surface with regular morphology. Relative to the first surface 100 of the substrate 10 , the substrate 10 includes a plurality of convex portions (not shown) protruding from the first surface 100 or a plurality of recessed portions (not shown) recessed in the first surface 100 (not shown). In a cross-sectional view, the convex part or the concave part may be in the shape of a hemisphere or a polygonal cone.

In one embodiment of the present invention, metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor deposition (HVPE), physical vapor deposition (PVD) or ion The electroplating method is used to form semiconductor stacks 20a, 20b with optoelectronic properties, such as light-emitting stacks, on the substrate 10. The physical vapor deposition method includes sputtering or evaporation.

The wavelength of light emitted by the light-emitting element 1 or 2 is adjusted by changing the physical and chemical composition of one or more layers in the semiconductor stack 20a, 20b. The materials of the semiconductor stacks 20a and 20b include III-V group semiconductor materials, such as Al _x In _y Ga _(1-xy) N or Al _x In _y Ga _(1-xy) P, where 0≦x, y≦1; (x+y)≦1. When the material of the semiconductor stack 20a and 20b is an AlInGaP series material, it can emit red light with a wavelength between 610 nm and 650 nm. When the semiconductor stack 20a, 20b is made of InGaN series materials, it can emit blue light with a wavelength between 400 nm and 490 nm, cyan light with a wavelength between 490 nm and 500 nm, or a wavelength between 500 nm. and green light between 570 nm. When the materials of the semiconductor stacks 20a and 20b are AlGaN series or AlInGaN series materials, ultraviolet light with a wavelength between 250 nm and 400 nm can be emitted.

The first semiconductor layers 21a, 21b and the second semiconductor layers 22a, 22b can be cladding layers or confinement layers, and they have different conductive types, electrical properties, polarities, or doping. elements to provide electrons or holes. For example, the first semiconductor layers 21a and 21b are n-type semiconductors, and the second semiconductor layers 22a and 22b are p-type semiconductors. Active layers 23a and 23b are respectively formed between the first semiconductor layers 21a and 21b and the second semiconductor layers 22a and 22b. Electrons and holes recombine in the active layers 23a and 23b driven by a current to convert electrical energy into light energy. to emit a light. The active layers 23a and 23b can be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), or a multi-layer quantum well structure (multi -quantum well, MQW). The material of the active layers 23a and 23b can be a neutral, p-type or n-type electrical semiconductor. The first semiconductor layer 21a, 21b, the second semiconductor layer 22a, 22b, or the active layer 23a, 23b may be a single layer or a structure including a plurality of sub-layers.

In one embodiment of the present invention, the semiconductor stack 20a, 20b may further include a buffer layer (not shown) between the first semiconductor layer 21a, 21b and the substrate 10 to release the substrate 10 and the semiconductor stack 20a. , the stress caused by the material lattice mismatch between 20b to reduce misalignment and lattice defects, thereby improving the epitaxial quality. The buffer layer may be a single layer or a structure including multiple sub-layers. In one embodiment, PVD aluminum nitride (AlN) can be used as a buffer layer formed between the semiconductor stacks 20a, 20b and the substrate 10 to improve the epitaxial quality of the semiconductor stacks 20a, 20b. In one embodiment, the target used to form PVD aluminum nitride (AlN) is composed of aluminum nitride. In another embodiment, a target composed of aluminum can be used, and aluminum nitride can be formed by reacting with the aluminum target in a nitrogen source environment.

As shown in Figures 1 to 2 and Figures 4 to 5, contact electrodes 40b and 40a are respectively provided on the second semiconductor layers 22b and 22a of the first light-emitting unit 1b and the second light-emitting unit 1a, and are electrically The second semiconductor layers 22a and 22b are connected to the first light-emitting unit 1b and the second light-emitting unit 1a. The contact electrodes 40a, 40b may cover almost the entire area of the second semiconductor layer 22a, 22b, or may be spaced apart from the edge of the semiconductor mesa 20m. For example, the contact electrodes 40a and 40b can cover more than 80% of the second semiconductor layer 22a and 22b, and more preferably can cover more than 90%. In order to prevent water vapor from flowing into the side walls of the light-emitting units 1a and 1b or the edge of the substrate 10 and causing damage, the edge portions of the contact electrodes 40a and 40b can be disposed inside the light-emitting units 1a and 1b relative to the edge of the semiconductor mesa 20m. The contact electrodes 40a and 40b may each include a reflective metal layer to reflect the light generated in the active layers 23a and 23b and traveling toward the contact electrodes 40a and 40b toward the second surface 110 of the substrate 10 . In one embodiment, the contact electrodes 40a, 40b may be formed as a single reflective metal layer, such as Ag or Al. However, it is not limited thereto. The contact electrodes 40a and 40b may also include a transparent oxide layer as an ohmic contact layer. In order to reduce contact resistance and improve current diffusion efficiency, the material of the transparent oxide layer includes a material that is transparent to the light emitted by the active layers 23a and 23b. The contact electrodes 40a, 40b include indium tin oxide (ITO), zinc oxide (Zinc Oxide, ZnO), zinc indium tin oxide (ZITO), indium zinc oxide (Zinc Indium Oxide, ZIO), oxide Zinc Tin Oxide (ZTO), Gallium Indium Tin Oxide (GITO), Gallium Indium Oxide (GIO), Gallium Zinc Oxide (GZO), aluminum-doped zinc oxide Translucent conductive oxides such as (Aluminum doped Zinc Oxide, AZO), fluorine doped tin oxide (Fluorine Tin Oxide, FTO), and aluminum (Al), nickel (Ni), gold (Au), etc. have thicknesses less than At least one of the light-transmitting metal layers with a thickness of 500 Angstroms. The light-transmissive conductive oxide may also include various dopants.

In the embodiment of the present invention, the first electrodes 51b, 51a and the second electrodes 52b, 52a of the light-emitting element 1 or 2 are formed on the same side of the substrate 10. The light-emitting element 1 or 2 can be a flip chip structure or a formal lateral chip structure.

As shown in Figures 1 to 2 and Figures 4 to 5, the first electrodes 51b and 51a are respectively provided on the first semiconductor layers 21b and 21a of the first light-emitting unit 1b and the second light-emitting unit 1a. The second electrodes 52b, 52a are respectively provided on the second semiconductor layers 21b, 21a and/or the contact electrodes 40b, 40a of the first light-emitting unit 1b and the second light-emitting unit 1a.

The first electrodes 51b, 51a and the second electrodes 52b, 52a can be formed together using the same material in the same process to have the same metal stack. The first electrodes 51b, 51a and the second electrodes 52b, 52a include a metal with high reflectivity, such as an aluminum (A1) layer, and the high-reflectivity metal layer may include titanium (Ti), chromium (Cr) or nickel (Ni). ) formed on the adhesive layer. Furthermore, a barrier layer of single layer or composite layer structure of nickel (Ni), chromium (Cr), gold (Au), etc. can be formed on the metal layer with high reflectivity to protect the metal layer with high reflectivity. and avoid surface oxidation. The first electrodes 51b, 51a and the second electrodes 52b, 52a may include, for example, a multi-layer structure of Cr/Al/Ni/Ti/Ni/Ti/Au/Ti.

As shown in Figures 1 to 2 and Figures 4 to 5, the current blocking layers 30b and 30a are respectively disposed between the second electrodes 52b and 52a and the contact electrodes 40b and 40a to prevent current from concentrating on the second electrode. 52b, near 52a, thus helping the horizontal dispersion of the current. The line width of the current blocking layers 30b, 30a is greater than the line width of the second electrodes 52b, 52a. The current blocking layers 30b, 30a are made of insulating material, and may be formed as a single layer or multiple layers. For example, the current blocking layers 30b, 30a may include _SiOx or _SiNx , and may include a Bragg reflector (DBR) in which insulating material layers with different refractive indexes are alternately stacked. In a top view, as shown in FIG. 1 , the top-view patterns of the current blocking layers 30b and 30a can be the same as the top-view patterns of the second electrodes 52b and 52a , or as shown in FIG. 4 , the top-view patterns of the current blocking layers 30b and 30a can be the same. The top view pattern may be different from the top view pattern of the second electrodes 52b, 52a.

As shown in Figure 2 or Figure 5, the insulating layer 60 covers the first semiconductor layers 21b, 21a and the side surfaces of the semiconductor mesas 20mb, 20ma from around the light-emitting units 1b, 1a. The insulating layer 60 partially covers the first semiconductor layer 21b at the first convex portion 210b of the first light-emitting unit 1b and forms the first insulating layer opening 601b, and partially covers the first semiconductor layer at the through hole 200 of the second light-emitting unit 1a. layer 21a and form a first insulating layer opening 601a. The insulating layer 60 partially covers the second semiconductor layer 22b at the semiconductor mesa 20mb of the first light-emitting unit 1b and forms a second insulating layer opening 602b, and partially covers the second semiconductor layer 22a at the semiconductor mesa 20ma of the second light-emitting unit 1a. And the second insulation layer opening 602a is formed.

As shown in Figures 1-2 and 4-5, the first extended electrode 71 and the second extended electrode 72 are respectively located on the semiconductor mesa 20ma of the second light-emitting unit 1a and the semiconductor mesa of the first light-emitting unit 1b. 20mb, and are electrically connected to the first semiconductor layer 21a of the second light-emitting unit 1a and the second semiconductor layer 22b of the first light-emitting unit 1b respectively. The first extended electrode 71 can directly contact the first electrode 51a of the second light-emitting unit 1a through the first insulating layer opening 601a, and the second extended electrode 72 can directly contact the first light-emitting unit 1b through the second insulating layer opening 602a. second electrode 52b.

The insulating layer 60 is disposed between the first electrodes 51b, 51a, the second electrodes 52b, 52a, the first extended electrodes 71, and the second extended electrodes 72, and includes first insulating layer openings 601b, 601a to expose the first electrodes 51b respectively. , 51a and the second insulating layer openings 602b, 602a to expose the second electrodes 52b, 52a respectively. As shown in Figure 1 or Figure 4, the first insulation layer opening 601b of the insulation layer 60 exposes the first electrode 51b located at the first protrusion 210b of the first light-emitting unit 1b, and the second insulation layer of the insulation layer 60 The layer opening 601a exposes the first electrode 51a located at the through hole 200 of the second light emitting unit 1a. As shown in FIG. 2 or FIG. 5 , the first extended electrode 71 contacts the first electrode 51 a through the first insulating layer opening 601 a and is electrically connected to the first semiconductor layer 21 a of the second light-emitting unit 1 a. The second extended electrode 72 contacts the second electrode 52b through the second insulating layer opening 602b and is electrically connected to the second semiconductor layer 22b of the first light emitting unit 1b.

As shown in Figures 1 to 2 and Figures 4 to 5, the connection electrode 70 partially covers the first light-emitting unit 1b, the second light-emitting unit 1a, and the trench 1000. The connection electrode 70 includes a first connection portion 702 located on the first protrusion 210b of the first light-emitting unit 1b and in contact with the first electrode 51b of the first light-emitting unit 1b, and located on the semiconductor mesa 20ma of the second light-emitting unit 1a and in contact with The second connection portion 701 contacted by the second electrode 52a of the second light-emitting unit 1a, and the bridge portion 700 located on the trench 1000.

In order to connect the adjacent light-emitting units 1a and 1b, as shown in Figures 3 and 6, the bridge portion 700 of the connecting electrode 70 spans the trench 1000 and covers the first semiconductor layer 21a of the adjacent light-emitting units 1a and 1b, The first side 211a, 211b of 21b. That is, in this embodiment, the semiconductor stack 20b, 20a of each light-emitting unit 1a, 1b has four edge portions, but the connection electrode 70 only covers one of these edge portions.

The connection electrode 70 in Figure 1 illustrates that the first connection part 702 covers two first electrodes 51b. However, the first connection part 702 can also cover one first electrode 51b or three or more first electrodes 51b as shown in Figure 4. An electrode 51b (not shown). According to an embodiment, as shown in FIG. 1 or FIG. 4 , the number of second electrodes 52 a in contact with the second connection part 701 is greater than the number of first electrodes 51 b in contact with the first connection part 702 . Increasing the number of connecting electrodes 70 in contact with the first electrode 51b and the second electrode 52a can improve the current dispersion of the light emitting element 1 or 2. The connection electrode 70 is electrically connected to the first electrode 51b on the first light-emitting unit 1b through the first insulating layer opening 601b, and may be connected to the second light-emitting unit 1a through the second insulating layer opening 602a of the second light-emitting unit 1a. The two electrodes 52a are electrically connected. Therefore, the first light-emitting unit 1 b and the second light-emitting unit 1 a are electrically connected to each other in series through the connecting electrode 70 .

According to an embodiment, when viewed from above, as shown in Figures 3 and 6, the first connection portion 702 of the connection electrode 70 covers the semiconductor mesa 20mb and the first convex portion 210b of the first light-emitting unit 1b, and has corresponding in the shape of the second recess 220b. Specifically, the first connecting portion 702 includes a first connecting portion flat side 7021, and a first connecting protrusion 7022 protruding from the first connecting portion flat side 7021. The formation position and/or shape of the first connection protrusion 7022 corresponds to the second recess 220b of the semiconductor mesa 20mb of the first light-emitting unit 1b. The second connection portion 701 includes a third recess 220a whose flat side 7011 is not parallel to the semiconductor mesa 20ma of the second light-emitting unit 1a. The first connecting portion flat edge 7021 of the first connecting portion 702 may be substantially parallel to the second connecting portion flat edge 7011 of the second connecting portion 701 .

According to an embodiment, when viewed from above, as shown in Figures 1 and 4, a plurality of second electrodes 52a, 52b are disposed on two opposite sides of the second recesses 220a, 220b to disperse the current.

The number of the first insulating layer opening 601a, 601b and the second insulating layer opening 602a, 602b may be one, but is not limited thereto, and may also be multiple. The number of the first insulating layer openings 601a, 601b and the second insulating layer openings 602a, 602b depends on the number of the first electrodes 51b, 51a and the second electrodes 52b, 52a to electrically connect the first electrodes 51a, 51b, the second Electrodes 52a, 52b, connection electrode 70, first extension electrode 71, and second extension electrode 72.

As shown in Figures 3 and 6, there is a first distance D1 between the first electrode 51b and the first protrusion 210b, a second distance D2 between the first electrode 51b and the second recess 220b, and the first distance D1 is greater than the second distance D2. In another embodiment, the first distance D1 is smaller than or substantially the same as the second distance D2. The first electrode 51b includes a diameter or a width greater than or equal to the first pitch D1, and/or greater than or equal to the second pitch D2. A radius R of the first electrode 51b may be less than or equal to the first distance D1. There is a third distance D3 between the first side 211b and the second side 222b. The third distance D3 is less than or equal to the first distance D1, and/or the third distance D3 is greater than or equal to the second distance D2. In this embodiment, the third distance D3 is larger than the second distance D2 but smaller than the first distance D1. As shown in FIG. 3 , the distance S between the trenches 1000 is smaller than the first distance D1 , the second distance D2 , and/or the third distance D3 . As shown in FIG. 6 , the distance S1 or S2 between the trenches 1000 is less than the first distance D1 and/or the third distance D3, but is greater than, less than, or equal to the second distance D2.

As shown in Figure 3, there is a first minimum width W1 between the first connection convex part 7022 and the second recess 220b, and there is a second minimum width W2 between the first connection part flat edge 7021 and the second side 222b. , where the first minimum width W1 is smaller than the second minimum width W2. As shown in Figure 6, there is a first minimum width W1 between the first connection convex part 7022 and the second recess 220b, and there is a second minimum width W2 between the first connection part flat edge 7021 and the second side 222b. , where the first minimum width W1 is approximately the same as the second minimum width W2. In another embodiment (not shown), the first minimum width W1 may be larger than the second minimum width W2.

The first extended electrode 71 and the second extended electrode 72 may include reflective metal layers. Therefore, the light generated in the active layers 23b and 23a and propagated toward the first extended electrode 71 and the second extended electrode 72 may be directed toward the substrate 10 One side reflection. For example, the first extended electrode 71 and the second extended electrode 72 may be formed as a single reflective metal layer, but are not limited thereto, and may also include a reflective layer and a blocking layer. The first extended electrode 71 and the second extended electrode 72 may use a metal layer such as nickel (Ni), titanium (Ti), or tungsten (W) as a barrier layer, and may use a reflective layer such as silver (Ag) or aluminum (Al). A metal layer with high efficiency is used as a reflective layer.

The first electrode pad 91 and the second electrode pad 92 have different conductivities. For example, the first electrode pad 91 can be an N-type electrode pad, and the second electrode pad 92 can be a P-type electrode pad. The first electrode pad 91 and the second electrode pad 92 are respectively located on the semiconductor mesa 20m of the second light-emitting unit 1a and the first light-emitting unit 1b, are established along the periphery of the first extended electrode 71 and the second extended electrode 72, and have Roughly the same shape. The first electrode pad 91 and the second electrode pad 92 contact the first extended electrode 71 and the second extended electrode 72 through the first protective layer opening 801 and the second protective layer opening 802 of the protective layer 80 respectively, and are electrically connected to The second light-emitting unit 1a and the first light-emitting unit 1b. The number of the first protective layer opening 801 and the second protective layer opening 802 depends on the number of the first electrode 51a and the second electrode 52b. As shown in Figure 1, the plurality of first protective layer openings 801 are each located between two adjacent second electrodes 52a, and the number of the plurality of first protective layer openings 801 is the same as the number of the first electrodes 51a. Each of the plurality of second protective layer openings 802 is located between two adjacent second electrodes 52b.

Since the first electrode pad 91 is disposed on the first electrode 51a and the second electrode 52a of the second light-emitting unit 1a, and the second electrode pad 92 is disposed on the second electrode 52b of the first light-emitting unit 1b, the first electrode pad The upper surfaces of 91 and the second electrode pad 92 are non-flat.

As shown in Figures 1 to 2 and Figures 4 to 5, the first protective layer opening 801 of the protective layer 80 does not overlap with the first insulating layer opening 601a of the insulating layer 60, and the second protective layer opening 801 of the protective layer 80 does not overlap. The protective layer opening 802 does not overlap with the second insulation layer opening 602b of the insulation layer 60 . Therefore, even if the solder invades the light-emitting element 1 or 2 through the first insulating layer opening 801 and the second insulating layer opening 802 of the protective layer 80 , the solder can be prevented from entering the first insulating layer opening 601 a and the second insulating layer of the insulating layer 60 The opening 602b is diffused, thereby preventing solder from contaminating the contact electrodes 40a, 40b.

The second electrodes 52b and the second protective layer openings 802 located in the first light-emitting unit 1a are arranged alternately with each other in the lateral direction. The second electrodes 52a and the first protective layer openings 801 located in the second light-emitting unit 1a are arranged alternately with each other in the lateral direction. The number or arrangement of the protective layer openings 801 and 802 can be selected considering not only the contamination of the extended electrodes 71 and 72 by solder but also the efficiency of current dispersion and the symmetry of the light-emitting pattern, and therefore can be modified in various ways.

In a top view, as shown in FIG. 7 , the semiconductor mesa 20m includes an arc angular radius greater than or equal to 5 μm, preferably greater than or equal to 10 μm, and more preferably greater than or equal to 15 μm to avoid interference from the second extended electrode 72 or the second extended electrode 72 . The current injected from the electrode pad 92 is concentrated at the corners of the semiconductor mesa 20m. The second extended electrode 72 or the second electrode pad 92 also has an arc angle corresponding to the semiconductor mesa 20m, and the arc angle of the second extended electrode 72 or the second electrode pad 92 has a maximum arc angle with the arc angle of the semiconductor mesa 20m. The distance R1 or R2 is greater than a maximum distance between one side of the second extended electrode 72 or the second electrode pad 92 and one side of the semiconductor mesa 20 m.

The first electrodes 51a, 51b, the second electrodes 52a, 52b, the first extended electrode 72, the connecting electrode 70, the second extended electrode 71, the first electrode pad 91, and the second electrode pad 92 include metallic materials, such as chromium (Cr). ), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), silver (Ag) and other metals or the above Material alloy. The first electrodes 51a, 51b, the second electrodes 52a, 52b, the first extended electrode 72, the connecting electrode 70, the second extended electrode 71, the first electrode pad 91, and the second electrode pad 92 may be composed of a single layer or multiple layers. . For example, the first electrodes 51a, 51b, the second electrodes 52a, 52b, the first extension electrode 72, the connection electrode 70, the second extension electrode 71, the first electrode pad 91, and the second electrode pad 92 may include a Ti/Au layer , Ti/Pt/Au layer, Cr/Au layer, Cr/Pt/Au layer, Ni/Au layer, Ni/Pt/Au layer, Cr/Al/Ni/Ti/Ni/Ti/Au/Ti, Cr/ Al/Cr/Ni/Au layer or Ag/NiTi/TiW/Pt layer. The first electrode pad 91 and the second electrode pad 92 can be used as current paths for external power supply to the first light-emitting unit 1b and the second light-emitting unit 1a. The first electrodes 51a, 51b, the second electrodes 52a, 52b, the first extended electrode 72, the connecting electrode 70, the second extended electrode 71, the first electrode pad 91, or the second electrode pad 92 include a thickness between 1 μm and 100 μm. is preferably between 1.2 μm and 60 μm, and more preferably between 1.5 μm and 6 μm.

The first extension electrode 72, the connection electrode 70, and the second extension electrode 71 can be formed together in the same process to have the same metal stack. The first electrode pad 91 and the second electrode pad 92 can be formed together in the same process to have the same metal stack. In this embodiment, the metal stacks in different processes have different thicknesses and stack structures.

The insulating layer 60 or the protective layer 80 may be a single-layer structure composed of silicon oxide, silicon nitride or silicon oxynitride. The insulating layer 60 or the protective layer 80 can also be alternately stacked by high refractive index layers and low refractive index layers to form a distributed Bragg reflector (DBR) structure to selectively reflect light of specific wavelengths. For example, an insulating reflective structure with high reflectivity can be formed by stacking layers of SiO ₂ /TiO ₂ or SiO ₂ /Nb ₂ O ₅ . When SiO ₂ /TiO ₂ or SiO ₂ /Nb ₂ O ₅ forms a distributed Bragg reflector (DBR) structure, each layer of the distributed Bragg reflector (DBR) structure is designed to emit light from the active layers 23a, 23b One or an integer multiple of the optical thickness that is one quarter of the wavelength. The optical thickness of each layer of a distributed Bragg reflector (DBR) structure can have a deviation of ±30% based on one or an integer multiple of λ/4. Since the optical thickness of each layer of the distributed Bragg reflector (DBR) structure will affect the reflectivity, E-beam evaporation is preferably used to form the distributed Bragg reflector (DBR) with stable control. The thickness of each layer of the DBR) structure. The insulating layer 60 or the protective layer 80 preferably has a thickness of 0.5 μm ~ 4 μm, preferably a thickness of 2.5 μm ~ 3.5 μm, and more preferably a thickness of 2.7 μm ~ 3.3 μm. The optical thickness difference between two adjacent high refractive index layers and low refractive index layers is less than 0.05λ, preferably less than 0.025λ. Optical thickness is the product of physical thickness and the refractive index of the material layer (n).

In an embodiment of the present invention, the light-emitting element 1 or 2 further includes a modulation layer 90 disposed on the second surface 110 of the substrate 10 . The modulation layer 90 includes a light field modulation layer, which can be formed by alternately stacking high refractive index layers and low refractive index layers to form a distributed Bragg reflector (DBR) structure. The light field modulation layer 90 selectively reflects and penetrates light emitted by the semiconductor stacks 20a and 20b with a peak wavelength λ, so that the transmittance of the light changes due to the incident angle, thereby adjusting the light-emitting element. Light field distribution of 1 or 2. The light field modulation layer 90 preferably has a thickness of 0.5 μm ~ 5 μm, preferably 1 μm ~ 3 μm, and more preferably 1.5 μm ~ 2 μm. The optical thickness difference between two adjacent high refractive index layers and low refractive index layers is greater than 0.025λ, preferably greater than 0.05λ, and more preferably greater than 0.1λ. Optical thickness is the product of physical thickness and the refractive index of the material layer (n). In one embodiment, the modulation layer 90 includes a filter layer, which can be alternately stacked by high refractive index layers and low refractive index layers to reflect or absorb light with wavelengths greater than, and/or less than a specific wavelength, and only transmit the light. Light of a specific wavelength, thereby purifying the light emitted by the light-emitting element 1 or 2. In one embodiment, the modulation layer 90 includes a filter layer, which can reflect or absorb light greater than a specific angle range by alternately stacking high refractive index layers and low refractive index layers, and only transmit light within a specific angle range. , thereby reducing the light emission angle of the light-emitting element 1 or 2.

Figure 8 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention. The light-emitting elements 1 and 2 in the aforementioned embodiment are mounted on the first pad 511 and the second pad 512 of the packaging substrate 51 in the form of flip-chip. The first gasket 511 and the second gasket 512 are electrically insulated by an insulating portion 53 containing insulating material. In flip-chip mounting, the second surface 110 of the substrate 10 of the light-emitting elements 1 and 2 is used as the main light extraction surface. In order to increase the light extraction efficiency of the light-emitting device 3, a reflective structure 54 can be provided around the light-emitting element 1 or 2. The light-emitting element 1 or 2 is electrically connected to the first pad 511 and the second pad 512 of the packaging substrate 51 via the first electrode pad 91 and the second electrode pad 92 respectively.

Figure 9 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention. The light-emitting device 4 is a bulb lamp and includes a lampshade 603, a reflector 604, a light-emitting module 611, a lamp holder 610, a heat sink 614, a connecting part 616, and an electrical connection component 618. The light-emitting module 611 includes a carrying part 606, and a plurality of light-emitting bodies 608 located on the carrying part 606, where the plurality of light-emitting bodies 608 can be the light-emitting elements 1, 2 or the light-emitting device 3 in the aforementioned embodiments.

Each embodiment listed in the present invention is only used to illustrate the present invention and is not intended to limit the scope of the present invention. Any obvious modifications or changes made by anyone to the present invention shall not depart from the spirit and scope of the present invention.

1, 2: Light-emitting components

1a: Second light-emitting unit

1b: First light-emitting unit

10:Substrate

10s: Side

100: first surface

110: Second surface

1000:Ditch

11: First side

12: Second side

20a, 20b: Semiconductor stack

20a1, 20b1: medial side

20a2, 20b2: outer side

20ma, 20mb: semiconductor mesa

200:Through hole

21a, 21b: first semiconductor layer

210a: first recess

210b: first convex part

211a, 211b: first side

22a, 22b: second semiconductor layer

220a: The third recess

220b: Second recess

222a, 222b: second side

23a, 23b: active layer

3:Lighting device

30a, 30b: current blocking layer

4:Lighting device

40a, 40b: Contact electrode

51:Package substrate

51a, 51b: first electrode

511:First gasket

512:Second gasket

52a, 52b: second electrode

53:Insulation Department

54: Reflective structure

60:Insulation layer

601a, 601b: first insulation layer opening

602a, 602b: Second insulation layer opening

603:Lampshade

604:Reflector

606: Bearing part

608: Luminous body

610: Lamp holder

611:Light-emitting module

614:Heat sink

616:Connection Department

618: Electrical connection components

70: Connect the electrode

700: Bridge crossing department

701: Second connection part

7011: Second connection part flat edge

702: First connection part

7021: First connecting part flat edge

7022: First connecting convex part

71: First extension electrode

72: Second extension electrode

80:Protective layer

801: First protective layer opening

802: Second protective layer opening

90:Light field modulation layer

91: First electrode pad

92: Second electrode pad

D1: first distance

D2: second distance

D3: The third distance

d1: first distance

d2: second distance

ISO: separation area

m1, m1’, m2, m2’: side

R:radius

R1, R2: maximum distance

S: spacing

S1: first spacing

S2: second spacing

W1: first minimum width

W2: The second smallest width

Figure 1 is a top view of a light-emitting element 1 disclosed in an embodiment of the present invention.

Figure 2 is a cross-sectional view of the light-emitting element 1 taken along the tangent line Y-Y' in Figure 1.

Figure 3 is a partially enlarged view of position I of Figure 1.

Figure 4 is a top view of a light-emitting element 2 disclosed in an embodiment of the present invention.

Figure 5 is a cross-sectional view of the light-emitting element 2 taken along the tangent line Y-Y' in Figure 4.

Figure 6 is a partially enlarged view of position II of Figure 4.

Figure 7 is a partial top view of position III in Figure 1 or position III in Figure 4.

Figure 8 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention.

Figure 9 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention.

1:Light-emitting component

1b: First light-emitting unit

1a: Second light-emitting unit

10:Substrate

100: first surface

1000:Ditch

11: First side

12: Second side

20a, 20b: Semiconductor stack

20ma, 20mb: semiconductor mesa

200:Through hole

21a, 21b: first semiconductor layer

210a: first recess

210b: first convex part

220a: The third recess

220b: Second recess

30a, 30b: current blocking layer

40a, 40b: Contact electrode

51a, 51b: first electrode

52a, 52b: second electrode

601a, 601b: first insulation layer opening

602a, 602b: Second insulation layer opening

70: Connect the electrode

700: Bridge crossing department

701: Second connection part

702: First connection part

71: First extension electrode

72: Second extension electrode

801: First protective layer opening

802: Second protective layer opening

91: First electrode pad

92: Second electrode pad

ISO: separation area

m1, m1’, m2, m2’: side

Claims (10)

A light-emitting element, including: a substrate including a first surface and a second surface opposite to the first surface; and a first light-emitting unit located on the first surface of the substrate, including a first semiconductor layer and a The semiconductor mesa is located on the first semiconductor layer; and a first electrode is provided on the first semiconductor layer of the first light-emitting unit, wherein when viewed from above one of the light-emitting elements, the first semiconductor layer includes a On one side, the semiconductor mesa includes a second side and a second recess recessed in the second side, and there is a third spacing between the first side and the second side that is greater than or equal to the first side. a second distance between an electrode and the second recess. The light-emitting element described in item 1 of the patent application, wherein any side of the light-emitting element has a length less than or equal to 200 μm. The light-emitting element according to claim 1, wherein the first semiconductor layer includes a first convex portion protruding from the first side, and a first convex portion is included between the first electrode and the first convex portion. The distance is greater than the second distance between the first electrode and the second recess. As described in claim 1 of the patent application, the first electrode includes a width greater than the second spacing. The light-emitting element described in item 1 of the patent application includes a separation area exposing the first surface of the substrate, wherein the light-emitting element has a first side and a second side connected to the first side, and the separation area The area has a first distance on the first side and a second distance on the second side, and the first distance and the second distance have different widths. For the light-emitting element described in item 5 of the patent application, the first distance includes a width between 5 μm and 15 μm. For the light-emitting element described in item 6 of the patent application, the second distance includes a width between 3 μm and 9 μm. The light-emitting element described in item 3 of the patent application further includes an electrode pad located on the semiconductor mesa, wherein the semiconductor mesa includes a first arc angle, and the electrode pad has a second arc corresponding to the semiconductor mesa. The second arc angle of the electrode pad and the first arc angle of the semiconductor mesa have a maximum distance greater than a maximum distance between one side of the electrode pad and one side of the semiconductor mesa. The light-emitting element described in Item 3 of the patent application further includes a second light-emitting unit located on the substrate, and a trench located between the first light-emitting unit and the second light-emitting unit, wherein the trench includes a distance less than at this second distance. For the light-emitting element described in claim 9, the first light-emitting unit and the second light-emitting unit respectively include an inner side and an outer side, and compared with the inner side, the outer side is steeper.

Images