TWI659549B - Light-emitting device - Google Patents

Abstract

The invention provides a light-emitting element structure including: a semiconductor stack including a groove and a platform, wherein the groove has a bottom, the platform has an upper surface; a first insulation layer is located in the groove and the A portion of the upper surface of the platform; the first electrode system includes a first layer and a second layer, wherein: the first layer includes a first conductive material on a portion of the upper surface of the platform; and the second layer includes a The second conductive material is located on the first layer.

Description

Light emitting element

The present invention relates to a light-emitting element structure and a method for manufacturing the same, and more particularly, to a light-emitting element structure with electrodes having a first layer and a second layer and a method for manufacturing the same.

Light emitting diode is a widely used light source in semiconductor elements. Compared with traditional incandescent light bulbs or fluorescent tubes, light-emitting diodes have the characteristics of power saving and long service life. Therefore, they gradually replace traditional light sources and are used in various fields, such as traffic signs, backlight modules, and street lighting. , Medical equipment and other industries.

With the application and development of light-emitting diode light sources, the demand for brightness is getting higher and higher, how to increase its light-emitting efficiency to improve its brightness has become an important direction for the industry to work together.

FIG. 9 illustrates an existing LED package 30: a semiconductor LED chip 32 including a package structure 31 and a package structure 31, wherein the semiconductor LED chip 32 has a pn junction 33, and the package structure 31 is usually a thermosetting material, such as a ring Epoxy, or thermoplastic materials. The semiconductor LED chip 32 is connected to the two conductive brackets 35 and 36 through a wire 34. Because epoxy resins are subject to degradation at high temperatures, they can only operate in low temperature environments. In addition, epoxy has a high thermal resistance, so that the structure of FIG. 9 only provides a high-resistance heat dissipation path for the semiconductor LED chip 32, and limits the low power of the LED package 30. Consuming application.

The invention provides a light emitting element structure including: a semiconductor stack including a groove and a platform, wherein the groove has a bottom and the platform has an upper surface; a first insulation layer is located in the groove and on the upper surface of the platform; A partial region; the first electrode system includes a first layer and a second layer, wherein: the first layer includes a first conductive material on a portion of the upper surface of the platform; and the second layer includes a second conductive material, Located on the first floor.

The present invention provides a structure of a light emitting element, wherein the first conductive material forming the first layer of the first electrode and the second conductive material forming the second layer of the first electrode are different; The reflectivity is greater than the reflectivity of the second layer of the first electrode to the light, and the reflectivity of the second layer to the light is greater than 60%.

In order to make the description of the present invention more detailed and complete, please refer to the following description and cooperate with the drawings of FIGS. 1-8 and FIG. 10. A top view of a light emitting element according to a first embodiment of the present invention is shown in FIG. 1A: a light emitting element includes a substrate (not shown) and a semiconductor stack; wherein the semiconductor stack includes: a first conductive semiconductor layer 11 And forming an active layer (not shown) and a second conductive type semiconductor layer 12 on the first conductive type semiconductor layer 11. The second conductive type semiconductor layer 12 and the active layer are etched to expose the first conductive type semiconductor layer 11. Figure 1B is a cross-sectional view cut along the AA 'cross section line, including a groove and a platform, wherein the groove has a bottom; the platform has an upper surface. In this embodiment, the upper surface of the platform is one of the surfaces of the second conductive semiconductor layer 12: the bottom of the groove exposes the first conductive semiconductor layer 11, and the groove passes through the active layer 21. After the light-emitting element is formed, a voltage is used to drive the light-emitting element, so that the first conductive semiconductor layer 11 provides electrons, and the second conductive semiconductor layer 12 provides holes. . As shown in FIGS. 2A and 2B, a second electrode 13 is formed on the first conductive type semiconductor layer 11 at the bottom of the groove, and the second electrode 13 is electrically connected to the first conductive type semiconductor layer 11.

As shown in FIG. 3A, the cross-sectional area cut along the AA 'cross-section line and the BB' cross-section line has different subsequent structures and processes, so they are described separately below. First, as shown in FIG. 3B, the cross-sectional area cut along the AA ′ cross-section line forms a partial region of the first insulating layer 14 in the groove and the upper surface of the platform, and covers the second electrode 13.

A first electrode and a first layer 15 are formed on a part of the upper surface of the platform and separated from the first insulation layer 14 without overlapping, as shown in FIGS. 4A and 4B. In this embodiment, the first electrode first layer 15 includes a first conductive material, which may be, for example, a metal; wherein the first conductive material includes at least one material selected from the group consisting of silver, platinum, and gold. The first electrode layer 15 has a thickness of 500 to 5000 angstroms. Then, a first electrode second layer 16 is formed on the first layer 15, wherein the first electrode second layer 16 covers the first layer 15 and at least part of the first insulating layer 14; as shown in FIGS. 5A and 5B. In this embodiment, the first electrode second layer 16 includes a second conductive material, such as metal; wherein the second conductive material includes at least one material selected from the group consisting of nickel, aluminum, copper, chromium, and titanium. group. The first electrode second layer 16 has a thickness of 2000 angstroms to 1.5 μm. In another embodiment, the first conductive material forming the first layer 15 and the second conductive material forming the second layer 16 are different; the reflectivity of the light generated by the first layer 15 to the light emitting element is greater than that of the second layer 16 pairs. The reflectivity of this light. The reflectivity of the second layer 16 to this light is preferably greater than 60%.

As shown in FIGS. 6A and 6B, a second insulating layer 17 is formed on the first electrode second layer 16; the space between the second insulating layer 17 exposes the upper surface of the first electrode second layer 16. The region of the second insulating layer 17 corresponds substantially to the region of the first insulating layer 14. In this embodiment, the second insulation layer 17 on the edge of the light-emitting element can be in direct contact with the first insulation layer 14. The material constituting the first insulating layer 14 and the material constituting the second insulating layer 17 may be the same or different, and the material constituting the two may be silicon oxide, silicon nitride, aluminum oxide, zirconia, or titanium oxide. As shown in FIGS. 7A and 7B, a first electrode pad 18 is formed on the second insulation layer 17 and a space between the second insulation layer 17; the first electrode pad 18 and the first electrode first layer 15 and The second layer 16 is electrically connected.

Next, Fig. 3C shows a cross-sectional area cut along the BB 'cross-section line of Fig. 3A, forming a part of the first insulation layer 14 located in the groove and on the upper surface of the platform. In this embodiment, a channel 20 is formed in a region of the upper surface of the second electrode 13 that is not covered by the first insulation layer 14. A first electrode and a first layer 15 are formed on a part of the upper surface of the platform and separated from the first insulation layer 14 without overlapping, as shown in FIGS. 4A and 4C. In this embodiment, the first electrode first layer 15 includes a first conductive material, such as metal; wherein the first conductive material includes at least one material selected from the group consisting of silver, platinum, and gold. The first electrode first layer 15 has a thickness of 500 to 5000 angstroms. Then, a first electrode second layer 16 is formed on the first layer 15, wherein the first electrode second layer 16 covers the first layer 15 and at least part of the first insulating layer 14, as shown in FIGS. 5A and 5C. In this embodiment, the first electrode first layer 15 and the first electrode second layer 16 cover the groove. The first electrode second layer 16 includes a second conductive material, which may be, for example, a metal. The second conductive material includes at least one material selected from the group consisting of nickel, aluminum, copper, chromium, and titanium. The first electrode second layer 16 has a thickness of 2000 angstroms to 1.5 μm. In another embodiment, the first conductive material forming the first layer 15 and the second conductive material forming the second layer 16 are different; the reflectivity of the light generated by the first layer 15 to the light emitting element is greater than that of the second layer 16 pairs. The reflectivity of this light. The reflectivity of the second layer 16 to this light is preferably greater than 60%.

As shown in FIGS. 6A and 6C, a second insulating layer 17 is formed on the first electrode second layer 16 and on the plurality of first insulating layers 14. A part of the second insulating layer 17 is in direct contact with the first insulating layer 14. The material constituting the first insulating layer 14 and the material constituting the second insulating layer 17 may be the same or different, and the material constituting the two may be silicon oxide, silicon nitride, aluminum oxide, zirconia, or titanium oxide. As shown in FIGS. 7A and 7C, a second electrode pad 19 is formed on the second insulation layer 17 and in the area of the channel 20; and the second electrode pad 19 is electrically connected to the second electrode 13. Fig. 7C shows a cross-sectional area cut along the BB 'cross-section line in Fig. 7A. As shown in Fig. 7C, on a cross-sectional view of a light-emitting element, the first electrode second layer 16 and the second electrode 13 are Do not overlap each other. FIG. 8 is a top view of the light-emitting element 10 formed.

FIG. 10 is an exploded view of a light bulb according to another embodiment of the present invention. The light bulb 40 includes a lamp cover 41, a lens 42, a light emitting module 44, a lamp holder 45, a heat dissipation fin 46, a coupling portion 47, and an electrical connector 48. The light-emitting module 44 further includes a carrier plate 43 and a plurality of the light-emitting elements 10 of the foregoing embodiments located on the carrier plate 43.

The materials of the second electrode 13, the first electrode pad 18, and the second electrode pad 19 may be selected from: chromium (Cr), titanium (Ti), nickel (Ni), platinum (Pt), copper (Cu), and rhenium. (Au), aluminum (Al), tungsten (W), tin (Sn), or silver (Ag) is a metal material. The substrate (not shown) is a growth and / or carrying foundation. Candidate materials include transparent substrates; the transparent substrate materials can be sapphire, lithium aluminate (LiAlO ₂ ), zinc oxide (ZnO), gallium nitride (GaN), aluminum nitride (AlN), glass, diamond , CVD diamond, Diamond-Like Carbon (DLC), spinel (MgAl ₂ O ₄ ), silicon oxide (SiO _X ), and lithium gallate (LiGaO ₂ ).

The above-mentioned first conductive type semiconductor layer 11 and the second conductive type semiconductor layer 12 are different in electrical properties, polarity, or dopants from at least two parts of each other, or are single layers of a semiconductor material for providing electrons and holes, respectively. Or multiple layers ("multi-layer" means two or more layers, the same applies hereinafter). The electrical selection can be a combination of at least any two of p-type, n-type, and i-type. The active layer 21 is located between the first conductive type semiconductor layer 11 and the second conductive type semiconductor layer 12 and is an area where electric energy and light energy may be converted or induced to be converted. Those who convert or induce light energy such as light-emitting diodes, liquid crystal displays, and organic light-emitting diodes; those who convert or induce light energy such as solar cells, photovoltaic diodes. The materials of the first conductive semiconductor layer 11, the active layer 21, and the second conductive semiconductor layer 12 include one or more elements selected from the group consisting of gallium (Ga), aluminum (Al), indium (In), and arsenic (As). , Phosphorus (P), nitrogen (N), and silicon (Si).

The light-emitting element according to another embodiment of the present invention is a light-emitting diode, and its light emission spectrum can be adjusted by changing the physical or chemical elements of a semiconductor single layer or multiple layers. Commonly used materials are aluminum gallium indium phosphide (AlGaInP) series, aluminum gallium indium nitride (AlGaInN) series, zinc oxide (ZnO) series, etc. The structure of the active layer (not shown) is: single heterostructure (SH), double heterostructure (DH), double-side double heterostructure (DDH), or multilayer quantum well (Multi-quantum well; MQW). Furthermore, adjusting the logarithm of the quantum well can also change the emission wavelength.

In one embodiment of the present invention, a buffer layer (not shown) may be optionally included between the first conductive semiconductor layer 11 and the substrate (not shown). This buffer layer is between the two metal material systems, which "transitions" the material system of the substrate to the material system of the semiconductor system. As for the structure of the light emitting diode, on the one hand, the buffer layer is a material layer for matching the lattice between the two materials. On the other hand, the buffer layer can also be a single layer, multiple layers, or structure that is used to combine two types of materials or two separate structures. The materials that can be used include organic materials, inorganic materials, metals, and semiconductors. Selected structures are: reflective layer, thermally conductive layer, conductive layer, ohmic contact layer, anti-deformation layer, stress release layer, stress adjustment layer, bonding layer, wavelength Conversion layer and mechanical fixing structure. In one embodiment, the material of the buffer layer may be AlN, GaN, and the forming method may be sputtering or atomic layer deposition (ALD).

A second conductive type contact layer (not shown) can be selectively formed on the second conductive type semiconductor layer 12. The contact layer is disposed on one side of the second conductive semiconductor layer far from the active layer 21. Specifically, the second conductive contact layer may be an optical layer, an electrical layer, or a combination thereof. The optical layer system can change electromagnetic radiation or light emitted from or into the active layer 21. As used herein, "change" refers to changing at least one optical characteristic of electromagnetic radiation or light. The aforementioned characteristics include, but are not limited to, frequency, wavelength, intensity, general efficiency, efficiency, color temperature, rendering index, and light field. (Light field), and angle of view. The electrical layer can make the voltage, resistance, voltage, and capacitance of at least one of the opposite sides of the second conductive contact layer change at least one of its value, density, and distribution, or there is a tendency to change. The constituent materials of the second conductive type contact layer include oxides, conductive oxides, transparent oxides, oxides with 50% or more penetrations, metals, relatively transparent metals, and 50% or more penetrations. Tritium, organic, inorganic, fluorescent, phosphor, ceramic, semiconductor, doped semiconductor, and undoped semiconductor. In some applications, the material of the second conductive contact layer is at least one of indium tin oxide, cadmium tin oxide, antimony tin oxide, indium zinc oxide, zinc aluminum oxide, and zinc tin oxide. Rhenium is a relatively light-transmitting genus, and its thickness is about 0.005 μm to 0.6 μm.

Although the above drawings and descriptions only correspond to specific embodiments, however, the elements, implementations, design guidelines, and technical principles described or disclosed in each embodiment are inconsistent, contradictory, or difficult to implement together. In addition, we shall be free to refer, exchange, match, coordinate, or merge as needed.

Although the present invention has been described as above, it is not intended to limit the scope, implementation order, or materials and manufacturing methods of the present invention. Various modifications and changes made without departing from the spirit and scope of the invention.

10‧‧‧Light-emitting element

11‧‧‧ the first conductive semiconductor layer

12‧‧‧Second conductive semiconductor layer

13‧‧‧Second electrode

14‧‧‧ the first insulation layer

15‧‧‧First electrode first layer

16‧‧‧first electrode second layer

17‧‧‧Second insulation layer

18‧‧‧first electrode pad

19‧‧‧Second electrode pad

20‧‧‧channel

21‧‧‧active layer

30‧‧‧LED package

31‧‧‧Packaging Structure

32‧‧‧LED Chip

33‧‧‧p-n interface

34‧‧‧ welding wire

35, 36‧‧‧ conductive bracket

40‧‧‧ bulb

41‧‧‧Shade

42‧‧‧ lens

43‧‧‧ Carrier Board

44‧‧‧light emitting module

45‧‧‧ lamp holder

46‧‧‧Cooling Fins

47‧‧‧Combination

48‧‧‧electrical connector

Figures 1-8 are top and cross-sectional views of a light emitting element structure according to the first embodiment of the present invention.

FIG. 9 is a structural diagram of a conventional light emitting element LED package.

FIG. 10 is an exploded view of a light bulb according to another embodiment of the present invention.

Claims (10)

A light-emitting element includes: a semiconductor stack including a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer; a groove passing through the second conductive semiconductor layer and the active layer, the The groove has a bottom to expose the first conductive type semiconductor layer, and the groove surrounds the second conductive type semiconductor layer; a conductive contact layer is located on the second conductive type semiconductor layer; a first electrode includes A first conductive material is located on the second conductive type semiconductor layer; a first electrode second layer includes a second conductive material and covers the first layer of the first electrode, wherein the first conductive material and the second The conductive material includes metal, and the first conductive material is different from the second conductive material; a second electrode is located at the bottom of the groove to electrically connect the first conductive semiconductor layer; a first insulating layer is located in the recess A second insulating layer covers the first insulating layer, includes a spaced region to expose the second layer of the first electrode, and a channel to expose the second electrode, and the A region of the two insulating layers and a region of the first insulating layer correspond to each other; a first electrode pad partially covers the groove, is located on the second conductive semiconductor layer and the space region, and is in contact with the first electrode. A second layer is in contact with each other, the second insulation layer is located between the second layer of the first electrode and the first electrode pad, and the second insulation layer is in direct contact with the first electrode pad; and a second electrode The pad partially covers the groove, is located on the second conductive type semiconductor layer and the channel, and is in direct contact with the second electrode. The light-emitting element according to item 1 of the scope of patent application, wherein the first conductive material includes a material selected from the group consisting of silver, platinum, and gold, and the second conductive material includes a material selected from the group consisting of nickel, A group of aluminum, copper, chromium, and titanium. The light-emitting element according to item 1 of the scope of patent application, wherein the materials of the first insulation layer and the second insulation layer are different, and the materials of the first insulation layer and the second insulation layer may be silicon oxide, nitride Silicon, aluminum oxide, zirconia or titanium oxide. The light-emitting element according to item 1 of the scope of patent application, wherein the channel is located at a corner of the light-emitting element when viewed from a top view of one of the light-emitting elements. According to the light-emitting element described in item 1 or 4 of the scope of patent application, viewed from a top view of one of the light-emitting elements, the second electrode is located on one side of the light-emitting element. The light-emitting element according to item 1 of the scope of patent application, wherein the second insulation layer located on one edge of the light-emitting element is in direct contact with the first insulation layer. The light-emitting element according to item 1 of the scope of patent application, wherein the second layer of the first electrode covers part of the first insulation layer and the groove. The light-emitting element according to item 1 of the scope of patent application, wherein the first insulating layer covers a portion of the second electrode. The light-emitting element according to item 1 of the application, wherein the active layer can emit a light, and the reflectivity of the first layer of the first electrode to the light is greater than the reflectance of the second layer of the first electrode to the light. And the reflectivity of the second layer of the first electrode to the light is greater than 60%. The light-emitting element according to item 1 of the patent application scope, wherein the material of the conductive contact layer comprises indium tin oxide, cadmium tin oxide, antimony tin oxide, indium zinc oxide, zinc aluminum oxide, or zinc tin oxide.