TW201946292A - Light-emitting device - Google Patents

Abstract

A light-emitting device includes a first semiconductor layer; a plurality of semiconductor pillars separated from each other and formed on the first semiconductor layer, the plurality of semiconductor pillars respectively includes a second semiconductor layer and an active layer; a first electrode covering one portion of the plurality of semiconductor pillars; and a second electrode covering another portion of the plurality of semiconductor pillars, wherein the plurality of semiconductor pillars under a covering region of the first electrode are separated from each other by a first space, the plurality of semiconductor pillars outside the covering region of the first electrode are separated from each other by a second space, and the first space is larger than the second space.

Description

Light emitting element

The present invention relates to a light-emitting element, and more particularly, to a light-emitting element capable of emitting an ultraviolet light. The light-emitting element includes a first semiconductor layer and a plurality of semiconductor pillars on the first semiconductor layer.

Light-Emitting Diode (LED) is a solid-state semiconductor light-emitting element, which has the advantages of low power consumption, low thermal energy generation, long working life, shock resistance, small size, fast response speed, and good photoelectric characteristics, such as Stable emission wavelength. Therefore, light-emitting diodes are widely used in household appliances, equipment indicators, and optoelectronic products.

A light-emitting element includes a first semiconductor layer; a plurality of semiconductor pillars are separated from each other and are located on the first semiconductor layer; each of the plurality of semiconductor pillars includes a second semiconductor layer and an active layer; a first electrode covers a plurality of semiconductor pillars; A portion; and a second electrode covering another portion of the plurality of semiconductor pillars, wherein the plurality of semiconductor pillars located below a coverage area of the first electrode include a first pitch to be separated from each other and are located on the cover of the first electrode The plurality of semiconductor pillars outside the region include a second pitch to be separated from each other, and the first pitch is greater than the second pitch.

A light-emitting element includes a first semiconductor layer; a plurality of semiconductor pillars are separated from each other and are located on the first semiconductor layer; each of the plurality of semiconductor pillars includes a second semiconductor layer and an active layer; a first electrode covers a plurality of semiconductor pillars; A portion; a second electrode covering another portion of the plurality of semiconductor pillars; and a semiconductor platform including a first semiconductor layer, an active layer, and / or a second semiconductor layer under the first electrode, wherein A plurality of semiconductor pillars outside a coverage area include a pitch to separate them from each other, and the semiconductor platform includes a width greater than the interval between the plurality of semiconductor pillars.

A light emitting element includes a first semiconductor layer; a plurality of semiconductor pillars are separated from each other and are located on the first semiconductor layer; each of the plurality of semiconductor pillars includes a second semiconductor layer and an active layer; a first contact layer includes a first contact And a first extension, the first contact includes an area larger than one of the plurality of semiconductor pillars, the first extension extends from the first contact and surrounds the plurality of semiconductor pillars; a first electrode covers the plurality of semiconductor pillars; A portion of a semiconductor pillar; and a second electrode covering another portion of the plurality of semiconductor pillars, wherein the first contact portion is located under the first electrode or the second electrode, and the first extension portion is located at the first electrode or the second electrode Under the electrode.

A light emitting element includes a first semiconductor layer including a first upper surface; an active layer including a surface on the first semiconductor layer and exposing a first upper surface of the first semiconductor layer; and a second semiconductor layer on the active layer The surface of the active layer is exposed, and the light-emitting element can emit a UV light.

In order to make the description of the present invention more detailed and complete, please refer to the description of the following embodiments and cooperate with related drawings. However, the examples shown below are for exemplifying the light-emitting element of the present invention, and the present invention is not limited to the following examples. In addition, the dimensions, materials, shapes, relative arrangement, etc. of the component parts described in the examples in the present specification are not limited, and the scope of the present invention is not limited thereto, but merely a simple description. In addition, the size or positional relationship of the components shown in each illustration may be exaggerated for clarity. Furthermore, in the following description, in order to appropriately omit detailed descriptions, components of the same or the same nature are displayed with the same name and symbol.

FIG. 1 is a top view of a light-emitting element 1 disclosed in an embodiment of the present invention. Fig. 2 is a sectional view taken along line A-A 'of Fig. 1;

As shown in FIGS. 1 and 2, a light-emitting element 1 includes a substrate 11; and a semiconductor stack is located on the substrate 11, wherein the semiconductor stack includes a first semiconductor layer 111 and a plurality of semiconductor pillars 12 are separated from each other. And located on the first semiconductor layer 111. Each of the plurality of semiconductor pillars 12 includes a second semiconductor layer 122 and an active layer 123. In one embodiment of the present invention, the semiconductor pillar 12 further includes a portion of the first semiconductor layer 111, and the active layer 123 is located between the first semiconductor layer 111 and the second semiconductor layer 122.

In one embodiment of the present invention, the substrate 11 is a growth substrate including a gallium arsenide (GaAs) wafer for growing aluminum gallium indium phosphide (AlGaInP), or for growing gallium nitride (GaN), nitrogen Indium gallium (InGaN) or aluminum gallium nitride (AlGaN) sapphire (Al2O3) wafer, gallium nitride (GaN) wafer or silicon carbide (SiC) wafer.

In one embodiment of the present invention, organic metal chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), hydride vapor deposition (HVPE), physical vapor deposition (PVD), or ions are used. The electroplating method is to form a plurality of semiconductor material layers composed of semiconductor materials and having optoelectronic characteristics on the substrate 11. The physical weather deposition method includes a sputtering method or an evaporation method. Then, the semiconductor material layer is patterned by lithography and etching, and a part of the semiconductor material layer is removed to form a plurality of semiconductor pillars 12 including a first semiconductor layer 111 and an active layer 123 and a second semiconductor layer 122. Semiconductor stack. The first semiconductor layer 111 and the second semiconductor layer 122 may be cladding layers, both of which have different conductivity types, electrical properties, polarities, or doped elements to provide electrons or holes, for example, The first semiconductor layer 111 is an n-type electrical semiconductor, and the second semiconductor layer 122 is a p-type electrical semiconductor. The active layer 123 is formed between the first semiconductor layer 111 and the second semiconductor layer 122. Electrons and holes are recombined in the active layer 123 under a current drive to convert electric energy into light energy to emit a light. The wavelength of light emitted by the light-emitting element 1 is adjusted by changing the physical and chemical composition of one or more layers in the semiconductor stack. The material of the semiconductor stack includes III-V semiconductor materials, such as AlxInyGa (1-x-y) N or AlxInyGa (1-x-y) P, where 0 ≦ x, y ≦ 1; (x + y) ≦ 1. According to the material of the active layer 123, when the semiconductor stack material is an AlInGaP series material, it can emit red light with a wavelength between 610 nm and 650 nm, and green light with a wavelength between 530 nm and 570 nm. When the laminated material is an InGaN series material, it can emit blue light with a wavelength between 450 nm and 490 nm, or when the semiconductor laminated material is an AlGaN series or an AlInGaN series material, it can emit a wavelength between 400 nm and 250 nm Between ultraviolet light. The active layer 123 may be a single heterostructure (SH), a double heterostructure (DH), a double-side double heterostructure (DDH), a multi-quantum well, MQW). The material of the active layer 123 may be a neutral, p-type or n-type electrical semiconductor.

In one embodiment of the present invention, a rhenium buffer layer (not shown) is further formed between the semiconductor stack and the substrate 11 to improve the epitaxial quality of the semiconductor stack. In one embodiment, aluminum nitride (AlN) can be used as the buffer layer. In one embodiment, the method for forming aluminum nitride (AlN) is PVD, and the target material is composed of aluminum nitride. In another embodiment, a target made of aluminum using PVD method is used to react with the aluminum target to form aluminum nitride under the environment of a nitrogen source.

In one embodiment of the present invention, the substrate 11 includes a sapphire (Al2O3) substrate, and the first semiconductor layer 111 includes an aluminum gallium nitride (AlGaN) layer. In order to reduce the epitaxial defects caused by the lattice difference between the aluminum gallium nitride layer and the sapphire substrate, aluminum nitride (AlN) is used as a buffer layer to be formed between the aluminum gallium nitride layer and the sapphire substrate. The aluminum buffer layer includes a thickness greater than 300 nm, preferably greater than 1000 nm, and more than 2500 nm to fill epitaxial defects. The aluminum nitride buffer layer includes carbon (C), hydrogen (H), and / or oxygen (O) with a doping concentration lower than 2E + 17. The aluminum (Al) composition percentage included in the aluminum nitride buffer layer is greater than the aluminum (Al) composition percentage included in the aluminum gallium nitride first semiconductor layer 111.

As shown in the top view in FIG. 1 and the cross-sectional view along line AA ′ in FIG. 2 after the plurality of semiconductor layers are formed on the substrate 11, the plurality are patterned by lithography and etching. A plurality of semiconductor layers are removed to form a semiconductor structure including a first semiconductor layer 111 and a plurality of semiconductor pillars 12 separated from each other. Each of the plurality of semiconductor pillars 12 includes a second semiconductor layer 122 and an active layer 123.

In one embodiment of the present invention, the plurality of semiconductor pillars 12 are separated from each other to expose the surface S1 of the first semiconductor layer 111. The substrate 11 includes a first sidewall 11s, the first semiconductor layer 111 includes a second sidewall 111s, and each of the plurality of semiconductor pillars 12 includes a third sidewall 12s. As shown in FIG. 2, the first sidewall 11 s of the substrate 11 is flush with the second sidewall 111 s of the first semiconductor layer 111, and the third sidewall 12 s of the semiconductor pillar 12 and the surface S1 of the first semiconductor layer 111 have a slant. Angle or straight angle.

In an embodiment of the present invention, the oblique angle between the third sidewall 12s of the semiconductor pillar 12 and the surface S1 of the first semiconductor layer 111 includes an angle between 10 degrees and 80 degrees, and preferably less than 60 degrees. More preferably, it is less than 40 degrees.

In one embodiment of the present invention (not shown), the first sidewall 11 s of the substrate 11 and the second sidewall 111 s of the first semiconductor layer 111 are spaced apart to expose a surface S2 of the substrate 11. There is an obtuse angle or a right angle between the second sidewall 111s of the first semiconductor layer 111 and the surface S2 of the substrate 11.

In one embodiment of the present invention, there is an oblique angle between the second sidewall 111s of the first semiconductor layer 111 and the surface S2 of the substrate 11 including an angle between 10 degrees and 80 degrees, preferably less than 60 degrees. More preferably, it is less than 40 degrees. A height between the surface S1 of the first semiconductor layer 111 and the surface S2 of the substrate 11 is greater than 4000 Å, preferably greater than 6000 Å, and more preferably greater than 8000 Å.

In one embodiment of the present invention, the surface S2 of the substrate 11 is a flat surface, wherein the flat surface includes a roughness (Root mean square roughness, Rq) of less than 8 nm, preferably less than 5 nm, and more preferably Less than 2 nm.

In an embodiment of the present invention, the surface S2 of the substrate 11 includes a patterned surface (not shown), wherein the patterned surface includes a plurality of recesses extending from the surface S2 of the substrate 11 to the interior of the substrate 11 or a plurality of The convex portion extends from the surface S2 of the substrate 11 to the surface S1 of the first semiconductor layer 111. Viewed from a top view of the light emitting element 1, each of the plurality of concave portions or convex portions includes a circle, an oval, a rectangle, a polygon, or any other shape. Viewed from a top view of the light-emitting element 1, each of the plurality of concave portions or the plurality of convex portions includes a bottom flush with the surface S2 of the substrate 11, and a top opposite to the bottom, wherein the top may be a flat surface or a sharp point. A depth or a height between the top and the bottom includes between 0.1 μm and 2 μm, preferably between 0.2 μm and 0.9 μm, and more preferably between 0.5 μm and 0.7 μm. The bottom contains a width or diameter between 0.05 μm and 1 μm, preferably between 0.2 μm and 0.8 μm, and more preferably between 0.3 μm and 0.5 μm.

In an embodiment of the present invention, viewed from the top view of the light-emitting element 1 shown in FIG. 1, the semiconductor pillars 12 each include a circle, an oval, a rectangle, a polygon, or any shape.

In one embodiment of the present invention, reducing the diameter or width included in the semiconductor pillar 12 can reduce the forward voltage (Vf) of the light-emitting element 1 and increase the brightness of the light-emitting element 1. Viewed from a top view of the light-emitting element 1, the semiconductor pillar 12 includes a diameter or a width greater than 4 μm and / or less than 80 μm, preferably less than 50 μm, and more preferably less than 20 μm.

In an embodiment of the present invention, the semiconductor pillars 12 may be arranged in a plurality of columns, and the semiconductor pillars 12 on any two adjacent columns or each adjacent two columns may be aligned with each other or staggered.

In one embodiment of the present invention, the semiconductor pillars 12 may be arranged in a first row and a second row. Two adjacent semiconductor pillars 12 on the same row include a first shortest distance. The semiconductor pillar 12 and a neighboring semiconductor pillar 12 located on the second column include a second shortest distance, wherein the first shortest distance is greater than or less than the second shortest distance. When an external current is injected into the light-emitting element 1, by dispersing the plurality of semiconductor pillars 12, the light field distribution of the light-emitting element 1 can be made uniform, and the forward voltage of the light-emitting element 1 can be reduced.

In one embodiment of the present invention, the plurality of semiconductor pillars 12 may be arranged in a first row, a second row, and a third row. The semiconductor pillars 12 on the first row and the semiconductor pillars 12 on the second row. A first shortest distance is included between them, and a second shortest distance is included between the semiconductor pillars 12 on the second column and a semiconductor pillar 12 on the third column, where the first shortest distance is less than the second shortest distance. When an external current is injected into the light-emitting element 1, by dispersing the plurality of semiconductor pillars 12, the light field distribution of the light-emitting element 1 can be made uniform, and the forward voltage of the light-emitting element 1 can be reduced.

A first contact layer 131 is formed on the surface S1 of the first semiconductor layer 111 by a physical vapor deposition method or a chemical vapor deposition method. The material of the first contact layer 131 includes a metal material, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni ), Platinum (Pt), rhodium (Rh) and other metals or alloys of the above materials.

In one embodiment of the present invention, the light emitted by the light-emitting element 1 includes a wavelength greater than 370 nm, and the material of the first contact layer 131 includes a metal having high reflectivity, such as silver (Ag), aluminum (Al), and platinum ( Pt) or rhodium (Rh). In order to increase the reflectivity of the first contact layer 131, the metal layer containing silver (Ag), aluminum (Al), platinum (Pt), or rhodium (Rh) has a thickness greater than 400 angstroms, preferably greater than 800 angstroms, more preferably greater than 1200 Angstroms.

In one embodiment of the present invention, the light emitted by the light-emitting element 1 includes a wavelength less than 370 nm, and the material of the first contact layer 131 does not include silver (Ag).

In one embodiment of the present invention, one side of the first contact layer 131 in contact with the surface S1 of the first semiconductor layer 111 includes chromium (Cr) or titanium (Ti) to increase the first contact layer 131 and the first semiconductor. The bonding strength of the layer 111. To reduce light loss, the thickness of the chromium (Cr) or titanium (Ti) layer is less than 1000 angstroms, preferably less than 800 angstroms, and more preferably less than 500 angstroms. In addition, in order to maintain sufficient bonding strength, the chromium (Cr) and / or titanium (Ti) layer includes a thickness greater than 10 angstroms, preferably greater than 50 angstroms, more preferably greater than 100 angstroms.

In one embodiment of the present invention, the first semiconductor layer 111 includes AlxGa (1-x) N, where 0.3> x> 0.8, preferably 0.35> x> 0.7, and more preferably 0.4> x> 0.6. In order to make the first contact layer 131 make ohmic contact with the surface S1 of the first semiconductor layer 111 and maintain sufficient bonding strength, the first contact layer 131 includes titanium (Ti) and aluminum (Al), where titanium (Ti) / aluminum ( Al) has a ratio between 0.1 and 0.2.

In one embodiment of the present invention, the first contact layer 131 includes a first contact portion P1 and a first extension portion E1. The first contact portion P1 includes a projected area on the first semiconductor layer 111, which is larger than a projected area of one of the plurality of semiconductor pillars 12 on the first semiconductor layer 111, wherein the projected area is perpendicular to the substrate 11. The projected area of one of the surfaces S2 in the normal direction. As shown in FIG. 1, the first extension portion E1 extends from the first contact portion P1 and surrounds the plurality of semiconductor pillars 12.

In one embodiment of the present invention, the first contact layer 131 includes a plurality of first contact portions P1 and a plurality of first extension portions E1, wherein the plurality of first extension portions E1 extend from the plurality of first contact portions P1 and They are connected to each other, and the plurality of first contact portions P1 are connected by a plurality of first extension portions E1.

As shown in FIG. 2, in an embodiment of the present invention, the first contact portion P1 of the first contact layer 131 includes a width larger than a width of the first extension portion E1.

A second contact layer 132 is formed on the second semiconductor layer 122 of the semiconductor pillar 12 by a physical vapor deposition method or a chemical vapor deposition method. The material of the second contact layer 132 includes a metal material, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni ), Platinum (Pt), rhodium (Rh) and other metals or alloys of the above materials.

In one embodiment of the present invention, the light emitted by the light-emitting element 1 includes a wavelength greater than 370 nm, and the material of the second contact layer 132 includes a metal with high reflectivity, such as silver (Ag), aluminum (Al), and platinum ( Pt) or rhodium (Rh). In order to increase the reflectivity of the second contact layer 132, the metal layer including silver (Ag), aluminum (Al), platinum (Pt) or rhodium (Rh) has a thickness greater than 400 angstroms, preferably greater than 800 angstroms, more preferably greater than 1200 Angstroms.

In one embodiment of the present invention, the light emitted by the light-emitting element 1 includes a wavelength less than 370 nm, and the material of the second contact layer 132 does not include silver (Ag).

In one embodiment of the present invention, the plurality of second contact layers 132 are respectively formed on the second semiconductor layers 122 of the plurality of semiconductor pillars 12, and the plurality of second contact layers 132 are separated from each other.

In one embodiment of the present invention, the second semiconductor layer 122 includes gallium nitride (GaN), aluminum gallium nitride (AlGaN), or boron nitride (BN), and the second semiconductor layer 122 includes a doping element, such as Magnesium (Mg) to form a p-type electrical semiconductor, wherein the doping element has a concentration greater than 9E + 18, preferably greater than 4E + 19, and more preferably greater than 1E + 20. The second contact layer 132 includes a transparent conductive material that is transparent to light emitted from the active layer 123 and can form an ohmic contact with the second semiconductor layer 122. Transparent conductive materials include non-metal materials, such as graphene, metals or metal oxides, such as indium tin oxide (ITO), or indium zinc oxide (IZO). Since the second contact layer 132 is formed on substantially the entire surface of the second semiconductor layer 122 and is in contact with the second semiconductor layer 122, the current is uniformly diffused throughout the second semiconductor layer 122 through the second contact layer 132.

In one embodiment of the present invention, the second contact layer 132 includes graphene, and the second contact layer 132 further includes a thin metal layer or a thin metal oxide layer. The material is, for example, nickel oxide (NiO) or cobalt oxide (Co3O4). Or copper oxide (Cu2O) is located between the second semiconductor layer 122 and graphene to form an ohmic contact with the second semiconductor layer 122. The thin metal layer or thin metal oxide layer includes a thickness between 0.1 and 50 nm, preferably between 0.1 and 20 nm, and more preferably between 0.1 and 10 nm.

In one embodiment of the present invention, the thickness of the second contact layer 132 may be in a range of 0.1 nm to 100 nm. If the thickness of the second contact layer 132 is less than 0.1 nm, the ohmic contact with the second semiconductor layer 122 cannot be effectively formed because the thickness is too thin. In addition, if the thickness of the second contact layer 132 is greater than 100 nm, the thickness of the second contact layer 132 partially absorbs light emitted from the active layer 123, thereby causing a problem that the brightness of the light-emitting element 1 decreases.

In one embodiment of the present invention, the positions of the first contact layer 131 and the second contact layer 132 formed on the semiconductor stack are staggered and do not overlap each other.

A first insulating layer 14 deposits an insulating material layer on the first contact layer 131 and the second contact layer 132 by a physical vapor deposition method or a chemical vapor deposition method. Then, a part of the insulating material layer is patterned by lithography and etching to form the first insulating layer 14, and a first opening 1401 of the first insulating layer 14 is formed on the first contact layer 131 to expose the first contact layer 131 and A second opening 1402 of the first insulating layer 14 is formed on the second contact layer 132 to expose the second contact layer 132.

In one embodiment of the present invention, the first contact layer 131 includes a plurality of first contact portions P1 and a plurality of first extension portions E1. The first insulation layer 14 includes a plurality of first openings 1401 located on the plurality of first contact portions P1, respectively, wherein the plurality of first extension portions E1 are covered by the first insulation layer 14.

In one embodiment of the present invention, the first insulating layer 14 includes a plurality of second openings 1402 to be respectively located on the plurality of semiconductor pillars 12. In other words, the plurality of second openings 1402 includes a number equal to the number of one of the plurality of semiconductor pillars 12.

In one embodiment of the present invention, the plurality of second openings 1402 of the first insulating layer 14 includes a number greater than one of the plurality of first openings 1401.

In one embodiment of the present invention, the second opening 1402 of the first insulating layer 14 includes a width smaller than a width of the first opening 1401.

In one embodiment of the present invention, the first insulating layer 14 covers the third sidewall 12s of the plurality of semiconductor pillars 12, covers the surface S1 of the first semiconductor layer 111, and covers the second sidewall 111s of the first semiconductor layer 111, and And / or cover the surface S2 of the substrate 11.

In one embodiment of the present invention, in addition to protecting the semiconductor structure, the first insulating layer 14 may be alternately stacked to form a Bragg reflector (DBR) structure by using two or more materials containing different refractive indices. Reflects light at a specific wavelength. The first insulating layer 14 is formed of a non-conductive material and includes organic materials such as Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy resin (Epoxy), and acrylic resin (Acrylic Resin). ), Cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide or fluorocarbon Polymer (Fluorocarbon Polymer), or inorganic materials, such as Silicone or Glass, or dielectric materials, such as aluminum oxide (Al2O3), silicon nitride (SiNx), silicon oxide (SiOx), oxide Titanium (TiOx) or magnesium fluoride (MgFx).

A first electrode contact layer 151 and a second electrode contact layer 152 are respectively formed in the first opening 1401 and the second opening 1402 of the first insulating layer 14 by a physical vapor deposition method or a chemical vapor deposition method. It extends and covers a part of the surface of the first insulating layer 14. The first electrode contact layer 151 is connected to the first contact portion P1 of the first contact layer 131 through the first opening 1401 of the first insulating layer 14. The second electrode contact layer 152 is connected to the plurality of second contact layers 132 through the second opening 1402 of the first insulating layer 14.

In one embodiment of the present invention, the second electrode contact layer 152 covers a portion of the plurality of semiconductor pillars 12 and the first contact layer 131, wherein the second electrode contact layer 152 is in contact with the first through the first insulating layer 14. The layer 131 is electrically isolated.

In one embodiment of the present invention, the first contact layer 131 includes a first contact portion P1 having a width W1 larger than a width W2 of the semiconductor pillar 12, and a width W1 of the first contact portion P1 of the first contact layer 131 is larger than that of the first contact portion 131. A width W3 of one of the electrode contact layers 151 is greater than a width W2 of the first electrode contact layer 151.

In one embodiment of the present invention, the first electrode contact layer 151 covers a portion of the first contact layer 131, and the second electrode contact layer 152 covers the entire second contact layer 132.

In one embodiment of the present invention, the first electrode contact layer 151 covers a portion of the first contact layer 131, and the second electrode contact layer 152 covers a portion of the second contact layer 132.

In one embodiment of the present invention, the first electrode contact layer 151 covers the entire first contact layer 131, and the second electrode contact layer 152 covers a part of the second contact layer 132.

In one embodiment of the present invention, the first electrode contact layer 151 and the second electrode contact layer 152 are separated from each other by a distance. In a top view of the light emitting element 1, the second electrode contact layer 152 surrounds a plurality of sidewalls of the first electrode contact layer 151.

In one embodiment of the present invention, the second electrode contact layer 152 includes an area larger than an area of the first electrode contact layer 151 in a top view of the light emitting element 1.

In one embodiment of the present invention, when an external current is injected into the light emitting device 1, the current is conducted to the first semiconductor layer 111 and the second semiconductor layer 122 through the first electrode contact layer 151 and the second electrode contact layer 152.

As shown in FIG. 1, the first electrode contact layer 151 is close to one side of the substrate 11, for example, to the left or right of the center line of the substrate 11.

In one embodiment of the present invention, the materials of the first electrode contact layer 151 and the second electrode contact layer 152 include metal materials, such as chromium (Cr), titanium (Ti), tungsten (W), gold (Au), and aluminum. (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), rhodium (Rh) and other metals or alloys of the above materials.

In one embodiment of the present invention, the light emitted by the light-emitting element 1 includes a wavelength less than 370 nm, and the material of the first electrode contact layer 151 and the second electrode contact layer 152 does not include silver (Ag). The material of the first electrode contact layer 151 and the second electrode contact layer 152 includes a metal having a high reflectivity to ultraviolet light, such as aluminum (Al), platinum (Pt), or rhodium (Rh). In order to increase the reflectivity of the first electrode contact layer 151 and the second electrode contact layer 152 to ultraviolet light, the layer containing aluminum (Al), platinum (Pt) or rhodium (Rh) includes a thickness greater than 4000 angstroms, preferably greater than 8000 Angstroms, more preferably greater than 10,000 Angstroms.

In one embodiment of the present invention, one side of the first electrode contact layer 151 in contact with the first contact layer 131 includes chromium (Cr) or titanium (Ti) to increase the first electrode contact layer 151 and the first contact layer. 131 joint strength. One side of the second electrode contact layer 152 in contact with the second contact layer 132 includes chromium (Cr) or titanium (Ti) to increase the bonding strength between the second electrode contact layer 152 and the second contact layer 132. In order to reduce the light loss caused by chromium (Cr) or titanium (Ti) to ultraviolet light, the layer containing chromium (Cr) or titanium (Ti) has a thickness of less than 1000 angstroms, preferably less than 800 angstroms, more preferably less than 500 angstroms. Moreover, in order to maintain sufficient joint strength, the layer containing chromium (Cr) and / or titanium (Ti) has a thickness of more than 10 angstroms, preferably more than 50 angstroms, more preferably more than 100 angstroms.

A second insulating layer 16 is formed on the first electrode contact layer 151 and the second electrode contact layer 152 by a physical vapor deposition method or a chemical vapor deposition method. Then, the insulating material layer is patterned by lithography and etching to form the second insulating layer 16, and the first opening 1601 and the second opening 1602 of the second insulating layer 16 are formed to expose the first electrode contact layer 151 and the first opening respectively. Two electrode contact layer 152.

In one embodiment of the present invention, the second insulating layer 16 includes one or more first openings 1601 and one or more second openings 1602, wherein the number of the first openings 1601 and the number of the second openings 1602 are The number can be the same or different.

In one embodiment of the present invention, the plurality of first openings 1601 of the second insulating layer 16 are respectively located on the plurality of first electrode contact layers 151, wherein the number of the plurality of first openings 1601 and the plurality of first electrode contact layers are The number of 151 is the same.

In the top view of FIG. 1, the first opening 1601 and the second opening 1602 of the second insulating layer 16 are located on both sides of the centerline of the substrate 11, respectively. For example, the first opening 1601 of the second insulating layer 16 is located on the right side of the center line of the substrate 11, and the second opening 1602 of the second insulating layer 16 is located on the left side of the center line of the substrate 11.

In one embodiment of the present invention, the first opening 1601 of the second insulating layer 16 includes a width smaller than that of the first opening 1401 of the first insulating layer 14.

In one embodiment of the present invention, the positions of the first opening 1601 of the second insulating layer 16 and the first opening 1401 of the first insulating layer 14 overlap, and the first opening 1601 of the second insulating layer 16 and the first insulating layer The first openings 1401 of 14 are all located on the first contact layer 131.

In one embodiment of the present invention, the positions of the second opening 1602 of the second insulating layer 16 and the second opening 1402 of the first insulating layer 14 are offset. Specifically, the second opening 1402 of the first insulating layer 14 is located on the second contact layer 132, and the second opening 1602 of the second insulating layer 16 is located on the first contact layer 131.

In one embodiment of the present invention, when the second insulating layer 16 is a laminated structure, the laminated structure includes two or more layers, and two materials with different refractive indexes are alternately stacked to form a Bragg reflector (DBR). ) Structure to selectively reflect light of a specific wavelength. The second insulating layer 16 is formed of a non-conductive material and includes organic materials such as Su8, benzocyclobutene (BCB), perfluorocyclobutane (PFCB), epoxy resin (Epoxy), and acrylic resin (Acrylic Resin). ), Cycloolefin polymer (COC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide or fluorocarbon Polymer (Fluorocarbon Polymer), or inorganic materials, such as Silicone or Glass, or dielectric materials, such as aluminum oxide (Al2O3), silicon nitride (SiNx), silicon oxide (SiOx), oxide Titanium (TiOx) or magnesium fluoride (MgFx).

A first electrode 171 and a second electrode 172 are formed on the second insulating layer 16 by electroplating, physical vapor deposition or chemical vapor deposition. In the top view of FIG. 1, the first electrode 171 is close to one side of the substrate 11, for example, to the right of the centerline of the substrate 11, and the second electrode 172 is close to the other side of the substrate 11, for example, to the left of the centerline of the substrate 11. The first electrode 171 covers the first opening 1601 of the second insulating layer 16 to be in contact with the first electrode contact layer 151 and forms an electrical connection with the first semiconductor layer 111 through the first contact layer 131. The second electrode 172 covers the second opening 1602 of the second insulating layer 16, is in contact with the second electrode contact layer 152, and passes through the second contact layer 132 to form an electrical connection with the second semiconductor layer 122.

In one embodiment of the present invention, the plurality of semiconductor pillars 12 located below a covered area of the first electrode 171 include a first distance D1 to separate them from each other. The plurality of semiconductor pillars 12 located outside the covered area of the first electrode 171 A second distance D2 is included to be separated from each other, and the first distance D1 is larger than the second distance D2.

In one embodiment of the present invention, the light emitting device 1 further includes a semiconductor platform. The semiconductor platform includes a first semiconductor layer, an active layer, and a second semiconductor layer, and is located below the first electrode 171, wherein the plurality of semiconductor pillars 12 located outside a covered area of the first electrode 171 include a second distance D2 to be separated from each other. And the second semiconductor layer of the semiconductor platform includes a width D2 which is larger than the second distance D2 between the plurality of semiconductor pillars.

In one embodiment of the present invention, the first contact portion P1 of the first contact layer 131 is located below the first electrode 171 and / or the second electrode 172, and the first extension portion E1 of the first contact layer 131 is located at the first Below the electrode 171 and the second electrode 172.

In one embodiment of the present invention, the first electrode 171 includes a size that is the same as or different from one of the second electrodes 172, and the size may be a width or an area.

In an embodiment of the present invention, in a top view of the light emitting element 1, the shape of the first electrode 171 is the same as or similar to the shape of the second electrode 172. For example, the shapes of the first electrode 171 and the second electrode 172 are rectangular. As shown in Figure 1.

In an embodiment of the present invention, the material of the first electrode 171 and the second electrode 172 includes a metal material, such as chromium (Cr), titanium (Ti), tungsten (W), aluminum (Al), indium (In), Metals such as tin (Sn), nickel (Ni), platinum (Pt), or alloys of the above materials. The first electrode 171 and the second electrode 172 may have a single layer or a stacked structure. When the first electrode 171 and the second electrode 172 are in a stacked structure, the first electrode 171 includes a first upper layer pad and a first lower layer pad, and the second electrode 172 includes a second upper layer pad and a first layer Two lower pads. The upper pads and the lower pads have different functions.

In one embodiment of the present invention, the function of the upper layer pad is mainly used for soldering and forming a lead. With the upper bonding pad, the light-emitting element 1 can be mounted on the package substrate in the form of a flip chip, using solder, or by eutectic bonding of an AuSn material, for example. The metal material of the upper pad includes highly ductile materials such as tin (Sn), nickel (Ni), cobalt (Co), iron (Fe), titanium (Ti), copper (Cu), gold (Au), tungsten (W), zirconium (Zr), molybdenum (Mo), tantalum (Ta), aluminum (Al), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os) and other metals or alloys of the above materials. The upper bonding pad may be a single layer or a stacked structure of the above materials. In one embodiment of the present invention, the material of the upper pad includes nickel (Ni) and / or gold (Au), and the upper pad has a single-layer or stacked structure.

In one embodiment of the present invention, the function of the lower bonding pad is to form a stable interface with the first electrode contact layer 151 and the second electrode contact layer 152. For example, the function of the first lower contact pad and the first electrode contact layer 151 is improved. The interface bonding strength, or the interface bonding strength of the second lower bonding pad and the second electrode contact layer 152 is increased. Another function of the lower solder pad is to prevent solder (Sn) in the AuSn eutectic from diffusing into the reflective structure and destroying the reflectivity of the reflective structure. Therefore, the lower pads include metal materials other than gold (Au) and copper (Cu), such as nickel (Ni), cobalt (Co), iron (Fe), titanium (Ti), tungsten (W), and zirconium (Zr). , Molybdenum (Mo), Tantalum (Ta), Aluminum (Al), Silver (Ag), Platinum (Pt), Palladium (Pd), Rhodium (Rh), Iridium (Ir), Ruthenium (Ru), Osmium (Os) And other metals or alloys of the above. The lower bonding pad may be a single layer or a stacked structure of the above materials. In one embodiment of the present invention, the lower bonding pad includes a stacked structure of titanium (Ti) / aluminum (Al), or a stacked structure of chromium (Cr) / aluminum (Al).

In one embodiment of the present invention, in order to prevent the tin (Sn) in the solder or the AuSn eutectic from diffusing into the reflective structure, the reflectivity of the reflective structure is destroyed. Therefore, one side of the first electrode contact layer 151 in contact with the first electrode 171 includes a metal material selected from the group consisting of titanium (Ti) and platinum (Pt). One side of the second electrode contact layer 152 in contact with the second electrode 172 includes a metal material selected from the group consisting of titanium (Ti) and platinum (Pt).

FIG. 3A is a partial cross-sectional view of a light-emitting element 2A disclosed in an embodiment of the present invention. FIG. 3B is a partial top view of the light-emitting element 2A disclosed in an embodiment of the present invention. The light-emitting element 2A and the light-emitting element 1 have substantially the same structure. Therefore, the light-emitting element 2A and the light-emitting element 1 have the same structure, and the description will be omitted or omitted here.

As shown in FIG. 3A and FIG. 3B, the light-emitting element 2A is a structural variation example of the semiconductor pillar 12 shown in the light-emitting element 1 of FIG. 2. In one embodiment of the present invention, the semiconductor stack includes a first semiconductor layer 221, an active layer 223, and a semiconductor pillar 22 on the active layer 223. The active layer 223 includes one or more well layers and one or more barrier layers arranged alternately with each other, wherein the well layers include AlxGa1-xN and 0.2> x> 0.4, and the barrier layers include AlyGa1-yN and 0.4> y> 0.7 . The semiconductor pillars 12 shown in the light-emitting element 1 of FIG. 2 can be changed into the semiconductor pillars 22 shown in FIGS. 3A and 3B, each of which includes a second semiconductor layer 222. In one embodiment of the invention, the semiconductor pillar 22 further includes a part of the active layer 223. The active layer 223 is located between the first semiconductor layer 221 and the second semiconductor layer 222, and the active layer 223 can emit a UV light.

In one embodiment of the present invention, the substrate 11 includes a first sidewall 11s, the first semiconductor layer 221 includes a second sidewall 221s, the second semiconductor layer 222 includes a third sidewall 222s, and the active layer 223 includes a sidewall 223s. As shown in FIG. 3A, the third sidewall 222s of the second semiconductor layer 222 and the sidewall 223s of the active layer 223 are spaced apart to expose the surface S3 of the active layer 223. The exposed surface S3 of the active layer 223 may be Well layer or barrier layer, the well layer includes AlxGa1-xN and 0.2> x> 0.4, and the barrier layer includes AlyGa1-yN and 0.4> y> 0.7. There is an obtuse angle or a straight angle between the third sidewall 222s of the second semiconductor layer 222 and the surface S3 of the active layer 223.

In an embodiment of the present invention, viewed from a top view of the light-emitting element 2A shown in FIG. 3B, the second semiconductor layer 222 includes a circle, an oval, a rectangle, a polygon, or any shape. The second semiconductor layer 222 is surrounded by the active layer 223, and a part of the surface S3 of the active layer 223 is exposed outside the covered area of the second semiconductor layer 222. A part of the surface S3 of the active layer 223 is not covered by the second semiconductor layer 222. The exposed surface S3 of the active layer 223 may be a well layer or a barrier layer. The well layer includes AlxGa1-xN and 0.2> x> 0.4. And the barrier layer includes AlyGa1-yN and 0.4> y> 0.7.

In one embodiment of the present invention, the active layer 223 is surrounded by the first semiconductor layer 221, and a part of the surface S1 of the first semiconductor layer 221 is exposed outside the coverage area of the active layer 223. The first semiconductor layer 221 includes AlGaN. A part of the surface S1 of the first semiconductor layer 221 is not covered by the active layer 223.

FIG. 4A is a partial cross-sectional view of a light-emitting element 2B disclosed in an embodiment of the present invention. FIG. 4B is a partial top view of the light-emitting element 2B disclosed in an embodiment of the present invention. The light-emitting element 2B and the light-emitting element 1 have substantially the same structure. Therefore, the light-emitting element 2B and the light-emitting element 1 have the same structure, and the description will be appropriately omitted or omitted here.

As shown in FIGS. 4A and 4B, the light-emitting element 2B is a structural variation example of the semiconductor pillar 12 shown in the light-emitting element 1 of FIG. 2. In one embodiment of the present invention, the semiconductor stack includes a first semiconductor layer 321, an active layer 323, and a plurality of semiconductor pillars 32 on the first semiconductor layer 321. The semiconductor pillars 32 each include a second semiconductor layer 322, and the active layer 323 can emit a UV light.

In one embodiment of the invention, the semiconductor pillar 32 further includes a part of the active layer 323. The active layer 323 is located between the first semiconductor layer 321 and the second semiconductor layer 322, and the active layer 323 can emit a UV light.

In an embodiment of the present invention, viewed from a top view of the light-emitting element 2B shown in FIG. 4B, the second semiconductor layer 322 includes a circle, an oval, a rectangle, a polygon, or any shape. The second semiconductor layer 322 is surrounded by the active layer 323, and a part of the surface S3 of the active layer 323 is exposed outside the covered area of the second semiconductor layer 322. A part of the surface S3 of the active layer 323 is not covered by the second semiconductor layer 322. The active layer 323 is surrounded by the first semiconductor layer 321, and a part of the surface S1 of the first semiconductor layer 321 is exposed outside the covered area of the active layer 323. A part of the surface S1 of the first semiconductor layer 321 is not covered by the active layer 323. Covering, wherein the first semiconductor layer 221 includes AlGaN.

FIG. 5 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention. The light-emitting element 1, the light-emitting element 2A, or the light-emitting element 2B in the foregoing embodiment is mounted on the first pad 511 and the second pad 512 of the package substrate 51 in the form of a flip chip. The first gasket 511 and the second gasket 512 are electrically insulated by an insulating portion 53 including an insulating material. Flip-chip mounting is to set the side of the growth substrate opposite to the pad formation surface used to form the electrode upward, with the growth substrate side as the main light extraction surface. In order to increase the light extraction efficiency of the light emitting device 3, a reflective structure 54 may be provided around the light emitting element 1, the light emitting element 2A, or the light emitting element 2B.

FIG. 6 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 including a lamp cover 602, a reflector 604, a light-emitting module 610, a lamp holder 612, a heat sink 614, a connection portion 616, and an electrical connection element 618. The light emitting module 610 includes a carrying portion 606 and a plurality of light emitting units 608 are located on the carrying portion 606. The plurality of light emitting units 608 may be the light emitting element 1, the light emitting element 2A, the light emitting element 2B, or the light emitting device in the foregoing embodiment. 3.

The embodiments listed in the present invention are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Any obvious modification or change made by anyone to the present invention will not depart from the spirit and scope of the present invention.

1,2A, 2B‧‧‧‧Light-emitting element

3, 4‧‧‧ light-emitting devices

11‧‧‧ substrate

111, 221, 321‧‧‧ the first semiconductor layer

122, 222, 322‧‧‧Second semiconductor layer

123,223,323‧‧‧‧active layer

12, 22, 32‧‧‧ semiconductor pillar

S1‧‧‧ Surface of the first semiconductor layer

S2‧‧‧ Surface of substrate

S3‧‧‧ surface of active layer

11s‧‧‧first side wall 11

111s, 221s‧‧‧Second sidewall

131‧‧‧first contact layer

P1‧‧‧First contact

14‧‧‧The first insulation layer

1402‧‧‧Second opening of the first insulating layer

12s, 222s

132‧‧‧Second contact layer

E1‧‧‧First extension

1401‧‧‧First opening of first insulating layer

151‧‧‧first electrode contact layer

152‧‧‧Second electrode contact layer

16‧‧‧Second insulation layer

1601‧‧‧First opening of second insulating layer

1602‧‧‧Second opening of the second insulating layer

171‧‧‧first electrode

172‧‧‧Second electrode

51‧‧‧Packaging substrate

511‧‧‧first gasket

512‧‧‧Second gasket

53‧‧‧Insulation Department

54‧‧‧Reflective structure

602‧‧‧Shade

604‧‧‧Mirror

606‧‧‧bearing department

608‧‧‧light-emitting unit

610‧‧‧light emitting module

612‧‧‧ lamp holder

614‧‧‧ heat sink

616‧‧‧Connection Department

618‧‧‧Electrical connection element

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

FIG. 2 is a cross-sectional view of a light-emitting element 1 disclosed in an embodiment of the present invention.

FIG. 3A is a partial cross-sectional view of a light-emitting element 2A disclosed in an embodiment of the present invention.

FIG. 3B is a partial top view of the light-emitting element 2A disclosed in an embodiment of the present invention.

FIG. 4A is a partial cross-sectional view of a light-emitting element 2B disclosed in an embodiment of the present invention.

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

FIG. 5 is a schematic diagram of a light emitting device 3 according to an embodiment of the present invention.

FIG. 6 is a schematic diagram of a light emitting device 4 according to an embodiment of the present invention.

Claims (10)

A light-emitting element can emit a UV light and includes: a substrate; an aluminum nitride buffer layer on the substrate; a first semiconductor layer containing Al _x Ga _(1-x) N on the aluminum nitride buffer layer, Where x>0; a semiconductor pillar is located on the first semiconductor layer, the semiconductor pillar includes a second semiconductor layer and an active layer; a first contact layer is located on the first semiconductor layer, and includes a first contact portion and A first extension portion, wherein the first extension portion surrounds the semiconductor pillar; a second contact layer on the second semiconductor layer; an insulating layer on the first contact electrode and the second contact layer, wherein the insulation The layer includes a first opening exposing the first contact portion of the first contact layer and a second opening exposing the second contact layer; a first electrode covers the first opening; and a second electrode covers the second opening . The light-emitting element according to item 1 of the patent application scope, wherein the substrate is a flat surface. The light-emitting element according to item 1 of the application, wherein the material of the first contact layer does not include silver (Ag). The light-emitting element according to item 1 of the patent application scope, wherein one side of the first contact layer in contact with the first semiconductor layer includes chromium (Cr) or titanium (Ti). The light-emitting element according to item 1 of the patent application scope, wherein 0.3> x> 0.8. The light-emitting element according to item 1 of the patent application scope, wherein in a top view of one of the light-emitting elements, the second electrode contact layer includes an area larger than an area of the first electrode contact layer. The light-emitting element according to item 1 of the patent application scope, wherein the UV light includes a wavelength less than 370 nm. The light-emitting element according to item 1 of the patent application scope, wherein the active layer comprises one or more well layers and one or more barrier layers are alternately arranged with each other, wherein the well layer comprises Al _x Ga _1-x N and 0.2 >x> 0.4, and the barrier layer includes Al _y Ga _1-y N and 0.4>y> 0.7. The light-emitting element according to item 1 of the patent application scope, wherein the second contact layer comprises a transparent conductive material or a metal material. The light-emitting element according to item 1 of the scope of patent application, wherein the second contact layer directly contacts the second semiconductor layer, and the second contact layer includes chromium (Cr), titanium (Ti), tungsten (W), and gold ( Au), aluminum (Al), indium (In), tin (Sn), nickel (Ni), platinum (Pt), rhodium (Rh) and other metals or alloys of the above materials.