TWI704687B - Light-emitting diode - Google Patents

Abstract

The application provides a light-emitting diode comprising a first light-emitting structure, comprising: a first area comprising a sidewall; a second area; and a first isolation path having an electrode isolation layer between the first area and the second area. The light-emitting diode further comprises an electrode contact layer covering the first area; an electrical connecting structure covering the second area; and an electrical contact layer under the electrical connecting structure, wherein the electrical contact layer directly contacts the electrical connecting structure; wherein each of the first area and the second area sequentially comprises a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, and the electrode contact layer covers the sidewall of the first area.

Description

Light-emitting diode

The present invention relates to a light-emitting diode structure and a manufacturing method thereof, in particular to a structure using an electrode insulating layer to improve leakage phenomenon and a manufacturing method thereof.

Light-emitting diodes are a widely used light source in semiconductor components. Compared with traditional incandescent bulbs or fluorescent tubes, light-emitting diodes have the characteristics of power saving and longer service life, so they are gradually replacing traditional light sources and 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, there is an increasing demand for brightness. How to increase its luminous efficiency to improve its brightness has become an important direction for the joint efforts of the industry.

Figure 14 depicts an LED package 300 for semiconductor light-emitting elements in the prior art: including a semiconductor LED chip 2 packaged by a package structure 1, wherein the semiconductor LED chip 2 has a pn junction 3, and the package structure 1 is usually made of thermosetting material , Such as epoxy or thermoplastic materials. The semiconductor LED chip 2 is connected to the two conductive supports 5 and 6 through a wire 4. Because epoxy resins are degraded at high temperatures, they can only operate in low temperature environments. In addition, epoxy has a high thermal resistance, so that the structure of Figure 14 only provides a high-resistance heat dissipation path for the semiconductor LED chip 2, which limits the low power of the LED package 1. Consuming applications.

The present invention provides a light emitting diode, including: a first light emitting diode, including: a first region including a sidewall; a second region; and a first isolation channel including an intervening first region And the electrode insulating layer between the second area. The light emitting diode further includes an electrode connection layer covering the first area; an electrical connection structure covering the second area; and an electrical connection layer located under the electrical connection structure, and the electrical connection layer directly contacts the electrical connection structure , Wherein the first region and the second region each sequentially include: a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor layer, and the electrode connection layer covers the sidewall of the first region.

1: Package structure

2: LED chip

3: p-n junction

4: wire bonding

5, 6: Conductive bracket

10: Growth substrate

11: The first conductivity type contact layer

12: First conductivity type semiconductor layer

12a: lower plane

13: active layer

14: Second conductivity type semiconductor layer

14a: upper plane

15b: second electrical electrode

15c: second electrical extension electrode

16: Temporary substrate

17: Electrical connection layer

18: Permanent substrate

19: Bonding layer

20: The first isolation

21: The second isolation

22: Electrode insulation layer

23: Insulation structure

24: Electrical connection structure

25: The second electrical soldering pad

26: Electrode connection layer

30: substrate

30a: first surface

40: Conductive wiring structure

50, 60: Electrical soldering pad

50A: First area

50B: second area

70: Isolate Road

80: Electrode insulation layer

100: the first light-emitting diode

200: second light-emitting diode

300: LED package

1000, 2000: LED array

Figures 1-12 are schematic cross-sectional views of the structure of the light-emitting diode array of the first embodiment of the present invention.

Fig. 13 is a top view of a light emitting diode array according to the second embodiment of the present invention.

Figure 14 is a structural diagram of a conventional light-emitting device.

The embodiments of the present invention will be described in detail and drawn in the drawings, and the same or similar parts will appear with the same numbers in the drawings and descriptions.

In order to make the description of the present invention more detailed and complete, please refer to the following description in conjunction with the drawings in Figures 1 to 13. The structure and manufacturing steps of the light-emitting diode array 1000 according to the first embodiment of the present invention are as follows: as shown in Figure 1, a growth substrate 10, such as a gallium arsenide substrate, is provided; a plurality of light-emitting diodes are directly epitaxially grown On this substrate. In this embodiment, there are two light-emitting diode units 100 and 200, but the number is not limited. Wherein, each light emitting diode includes a first conductivity type contact layer 11, a first conductivity type semiconductor layer 12, an active layer 13, and a second conductivity type semiconductor layer 14, as shown in FIG. Show. The first conductive type contact layer 11 may be n-type gallium arsenide (n-GaAs); the first conductive type semiconductor layer 12, an active layer 13, and a second conductive type semiconductor layer 14 are made of one or one material The above elements are selected from the group consisting of gallium (Ga), aluminum (Al), indium (In), arsenic (As), phosphorus (P), nitrogen (N) and silicon (Si); for example, it may be gallium phosphide (GaP) or aluminum gallium indium phosphide (AlGaInP).

Electrode structures, such as at least one second electrical type electrode 15b and a plurality of second electrical type extension electrodes 15c, are respectively formed on the second conductive semiconductor layer 14 in selective regions by vapor deposition. After joining a temporary substrate 16 on these electrodes, the growth substrate 10 is removed, as shown in FIGS. 3 and 4; the temporary substrate 16 may be glass. The first conductive type contact layer 11 is partially removed by a photolithography process to form a plurality of dot-like structures and a part of the lower surface 12a of the first conductive type semiconductor layer 12 is exposed, and then a part of the lower surface 12a and the plurality of second An electrical connection layer 17 is formed under the dot structure of a conductive contact layer 11, as shown in FIG. The material of the second electrical type electrode 15b and the plurality of second electrical type extension electrodes 15c can be selected from: chromium (Cr), titanium (Ti), nickel (Ni), platinum (Pt), copper (Cu), gold ( Metal materials such as Au), aluminum (Al), tungsten (W), tin (Sn), or silver (Ag). The material of the electrical connection layer 17 can be germanium/gold.

The lower surface 12a of the first conductive semiconductor layer 12 is etched into a rough surface by a wet etching method, as shown in FIG. 6. In addition, a permanent substrate 18, such as an alumina substrate, is provided; and a bonding layer 19 is formed on the substrate to form the structure shown in Fig. 7; or a bonding layer is formed on the lower surface 12a of the first conductive semiconductor layer 12 19 (not shown), the permanent substrate 18 is bonded under the lower surface 12a of the first conductive type semiconductor layer 12 with the bonding layer 19, so that the structures of FIGS. 6 and 7 are bonded together, and a plurality of A conductive contact layer point structure 11 and an electrical connection layer 17 are interposed between the lower surface 12a of the first conductive semiconductor layer 12 and the bonding layer 19, as shown in FIG. The temporary substrate 16 is removed to expose the second electrical type electrode 15b, the plurality of second electrical type extension electrodes 15c, and part of the upper surface 14a of the second conductivity type semiconductor layer 14, as shown in FIG. Inductively Coupled Plasma Ion Etching System (Inductively Coupled Plasma Reactive Ion Etching System) Dry etching the second conductive semiconductor layer 14 and the active layer 13 from top to bottom to expose part of the surface of the first conductive semiconductor layer 12 to form a first isolation channel 20 and a second isolation channel 21 ; Wherein the first isolation channel 20 separates the first light emitting diode 100 into a first area 50A and a second area 50B, and the distance between these two areas is not less than 25 μm. The second isolation channel 21 is located between the first light-emitting diode 100 and the third area, and a second light-emitting diode 200 is subsequently formed in the third area. Then, dry etching or wet etching is used to etch the upper surface 14a of the second conductive semiconductor layer 14 into a rough surface, as shown in FIG. 10. The inductively coupled plasma ion etching system is used to etch and remove part of the first conductivity type semiconductor layer 12 in the second isolation channel 21 again. Due to the different dry etching rates before and after the secondary dry etching, the sidewalls of the second conductive semiconductor layer 14, the active layer 13, and the first conductive semiconductor layer 12 in the second isolation channel 21 form a step shape, as shown in FIG.

In the first isolation channel 20, an electrode insulating layer 22 is formed along the sidewall of the second region 50B by an evaporation method, and the height of the electrode insulating layer 22 is greater than the height of the sidewall of the second region 50B. In the second isolation channel 21, an insulating structure 23 is formed by evaporation along a part of the upper surface and sidewalls of the second region 50B, and an insulating structure 23 is formed along part of the upper surface and the sidewalls of the second light emitting diode 200 by evaporation The method forms another insulating structure 23, wherein the material of the electrode insulating layer 22 and the insulating structure 23 can be dielectric materials such as silicon oxide, silicon nitride, aluminum oxide, zirconium oxide, or titanium oxide. An electrode connection layer 26 is formed to cover the sidewall and upper surface of the first region 50A, wherein the electrode connection layer 26 can be made of titanium-gold. Since the electrode connection layer 26 and the first conductivity type semiconductor layer 12, the active layer 13 and the second conductivity type semiconductor layer 14 of the first light emitting diode 100 cannot form electrical ohmic contacts, the electrical connection layer 17 is required. In order to form an electrical ohmic contact with the first conductive semiconductor layer 12. In the second isolation channel 21, an electrical connection structure 24 is formed above the insulating structure 23 of the second region 50B, the sidewalls, and the bottom of the second isolation channel 21; wherein the second conductivity type semiconductor of the first light emitting diode 100 The layer 14 electrically connects the structure 24 and the electrically connected layer 17 with the first conductivity type of the second light-emitting diode 200 by this The semiconductor layer 12 forms an electrical connection in series. A second electrical type bonding pad 25 is formed on the second electrical type electrode 15b. In addition, the electrode connecting layer 26 can be used as the first electrical soldering pad. When the electrode connecting layer 26 and the second electrical soldering pad 25 are connected to an external power source (not shown), the current provided by the external power source can be The electrode connection layer 26 flows through the first conductivity type semiconductor layer 12, the active layer 13, and the second conductivity type semiconductor layer 14 of the light emitting diode 100 through the electrical connection layer 17, and flows to the light emitting diode through the electrical connection structure 24. Polar body 200. The electrode connection layer 26 and the electrical connection structure 24 can be formed simultaneously with the second electrical bonding pad 25 by vapor deposition, and the constituent materials can be the same. After the above process steps, a light-emitting diode array 1000 with two light-emitting diodes 100 and 200 connected in series is formed. The light emitting diode 100 is separated by the first isolation channel 20 into a first area 50A and a second area 50B; wherein the first area 50A is covered by an electrode connection layer 26. The second electrical type bonding pad 25 is located on a part of the upper surface 14a of the second light emitting diode 200, and the upper surface of the electrode connection layer 26 and the upper surface of the second electrical type bonding pad 25 may be at the same level.

Figure 13 is a top view of a light-emitting diode array 2000 according to a second embodiment of the present invention. It shows a total of 10 light-emitting diodes including a first light-emitting diode 100 and a second light-emitting diode 200, which are electrically connected to each other. Light-emitting diode array in series. As shown in FIG. 13, the light-emitting diode array 2000 includes a substrate 30 with a first surface 30a; 10 light-emitting diodes are located on the first surface, including a first light-emitting diode 100 and a second light-emitting diode. The diode 200; a plurality of conductive wiring structures 40 are arranged on the first surface and are electrically connected to the light-emitting diodes; the two electrical solder pads 50, 60 are located on the first surface, and the two electrical solder pads and one An external power supply is electrically connected (not shown); an isolation channel 70 is located between any electrical soldering pad (for example: soldering pad 50) and any light-emitting diode (for example: light-emitting diode 100); The distance between the electrical bonding pad and the light emitting diode is not less than 25μm. When the distance between the electrical bonding pad and the light-emitting diode is too small, the semiconductor material is likely to remain on the sidewall of the light-emitting diode during the etching step of the light-emitting diode, causing current leakage. In isolation An electrode insulating layer 80 is formed on the sidewall of the light emitting diode in the channel 70 to improve this phenomenon. The substrate 30 is a supporting base, and may include a conductive substrate or a non-conductive substrate, a light-transmitting substrate or a light-impermeable substrate.

The first conductive type semiconductor layer 12 and the second conductive type semiconductor layer 14 are at least two parts of which are different in electrical properties, polarities or dopants, or are a single layer of semiconductor material used to provide electrons and holes, respectively Or multi-layer ("multi-layer" refers to two or more layers, the same hereinafter), and its electrical selection can be a combination of at least any two of p-type, n-type, and i-type. The active layer 13 is located between the first conductivity type semiconductor layer 12 and the second conductivity type semiconductor layer 14, and is a region where electrical energy and light energy may be converted or induced to convert.

According to the light-emitting diode described in the embodiment of the present invention, the light-emitting spectrum of the light-emitting diode can be adjusted by changing the physical or chemical elements of the semiconductor single layer or multilayer. Commonly used materials include 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 such as: 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 an embodiment of the present invention, a buffer layer (not shown) is further included between the first conductive type contact layer 11 and the growth substrate 10. The buffer layer is between the two material systems, so that the material system of the substrate "transitions" to the material system of the semiconductor system. For the structure of the light-emitting diode, on the one hand, the buffer layer is a material layer used to reduce the lattice mismatch between the two materials. On the other hand, the buffer layer can also be a single layer, multilayer or structure used to combine two materials or two separate structures. The materials that can be used include organic materials, inorganic materials, metals, and semiconductors; The selected structure is such as: reflective layer, thermal conductive layer, conductive layer, anti-deformation layer, stress release layer, stress adjustment Layers, bonding layers, wavelength conversion layers, and mechanical fixing structures. In one embodiment, the material of the buffer layer can be AlN, GaN, GaInP, InP, GaAs, AlAs, and the formation method can be Sputter or Atomic Layer Deposition (ALD).

A second conductivity type contact layer (not shown) can be further selectively formed on the second conductivity type semiconductor layer 14. The contact layer is disposed on a side of the second conductivity type semiconductor layer away from the active layer 13. Specifically, the second conductive type contact layer may be an optical layer, an electrical layer, or a combination of the two. The optical layer system can change the electromagnetic radiation or light from or entering the active layer (not shown). "Change" as used herein 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, flux, efficiency, color temperature, rendering index, and light field. (light field), and angle of view. The electrical layer can make the value, density, and distribution of at least one of the voltage, resistance, current, and capacitance between any set of opposite sides of the second conductive contact layer change or have a tendency to change. The constituent materials of the second conductive type contact layer include oxides, conductive oxides, transparent oxides, oxides with a transmittance of 50% or more, metals, relatively light-transmitting metals, and those with a transmittance of 50% or more. At least one of metal, organic, inorganic, phosphor, phosphor, ceramic, semiconductor, doped semiconductor, and undoped semiconductor. In some applications, the material of the second conductive type 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. If it is a relatively transparent metal, its thickness is about 0.005μm~0.6μm.

Although the above drawings and descriptions only correspond to specific embodiments respectively, however, the elements, implementations, design criteria, and technical principles described or disclosed in the various embodiments are in conflict, contradictory, or difficult to implement together. In addition, we can refer to, exchange, match, coordinate, or merge as needed.

Although the present invention has been described above, it is not intended to limit the scope of the present invention, the order of implementation, or the materials and manufacturing methods used. Various modifications and changes made to the present invention do not depart from the spirit and scope of the present invention.

11‧‧‧First conductivity type contact layer

12‧‧‧First conductivity type semiconductor layer

12a‧‧‧lower plane

13‧‧‧Active layer

14‧‧‧Second conductivity type semiconductor layer

14a‧‧‧Upper plane

15b‧‧‧Second electrical electrode

15c‧‧‧Second electrical extension electrode

17‧‧‧Electrical connection layer

18‧‧‧Permanent substrate

19‧‧‧Joint layer

20‧‧‧The First Path of Seclusion

21‧‧‧Second Path of Seclusion

22‧‧‧Electrode insulation layer

23‧‧‧Insulation structure

24‧‧‧Electrical connection structure

25‧‧‧Second electrical soldering pad

26‧‧‧Electrode connection layer

100‧‧‧First LED

50A‧‧‧First area

50B‧‧‧Second area

200‧‧‧Second LED

1000‧‧‧Light Emitting Diode Array

Claims (10)

A semiconductor element for emitting a light. The semiconductor element includes: a first semiconductor stack, including a first region and a second region, the first region having a first sidewall, and the second region having a first Two sidewalls; a second semiconductor stack; a first isolation channel formed between the first region and the second region; a second isolation channel formed between the first semiconductor stack and the second semiconductor stack Between the layers; an insulating layer formed in the first isolation channel and covering the second sidewall, an electrical connection layer, including a part located under the first semiconductor stack; and an electrode connection layer, directly contacting the The electrical connection layer covers the first sidewall; wherein, the second area is electrically connected to the electrode connection layer through the electrical connection layer. The semiconductor device described in claim 1, wherein the portion of the electrical connection layer overlaps with the first area in one direction but does not overlap with the second area. According to the semiconductor device described in item 1 or item 2 of the scope of the patent application, the first region further includes an upper surface, and the electrode connection layer covers the upper surface. The semiconductor device described in item 1 or item 2 of the scope of patent application, wherein the first region and the second region respectively include a first conductivity type semiconductor layer, an active layer and a second conductivity type semiconductor Layer, and the second conductivity type semiconductor layer of the first region and the second region are connected to each other. The semiconductor device described in item 1 or item 2 of the scope of patent application, wherein the part of the electrical connection layer is located under the first area. According to the semiconductor device described in item 1 or item 2 of the scope of patent application, the second region further has a third side wall, and the insulating layer covers the third side wall. The semiconductor device described in item 1 or item 2 of the scope of patent application, wherein the second region is located between the first region and the second semiconductor stack. The semiconductor device described in item 1 or item 2 of the scope of the patent application further includes a substrate under the first semiconductor stack. The semiconductor device described in item 8 of the scope of the patent application further includes a bonding layer bonding the substrate and the first semiconductor stack. The semiconductor device described in item 8 of the scope of patent application, wherein the substrate comprises alumina.

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