TWI612653B - Light-emitting diode - Google Patents

Abstract

The present invention provides a light emitting diode comprising: a first light emitting diode comprising: a first region comprising a sidewall; a second region; and a first isolation track comprising a first region And an electrode insulating layer between the second regions. The light emitting diode further comprises an electrode connecting layer covering the first region; an electrical connecting structure covering the second region; and an electrical connecting layer under the electrical connecting structure, and the electrical connecting layer directly contacting the electrical connecting structure The first region and the second region respectively comprise a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer, and the electrode connection layer covers the sidewall of the first region.

Description

Light-emitting diode

The present invention relates to a light emitting diode structure and a method of fabricating the same, and more particularly to a structure for improving leakage current using an electrode insulating layer and a method of fabricating the same.

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

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

Figure 14 depicts a prior art LED package 300 for a semiconductor light emitting device comprising: a semiconductor LED wafer 2 encapsulated by a package structure 1, wherein the semiconductor LED wafer 2 has a pn junction 3, and the package structure 1 is typically a thermoset material For example, epoxy or thermoplastic materials. The semiconductor LED chip 2 is connected to the two conductive supports 5, 6 through a wire 4. Because epoxy is degrading at high temperatures, it can only be operated in low temperature environments. In addition, epoxy has a high thermal resistance, so that the structure of FIG. 14 only provides a high-resistance heat dissipation path of the semiconductor LED chip 2, and limits the low-power of the LED package 1. Consumption application.

The present invention provides a light emitting diode comprising: a first light emitting diode comprising: a first region comprising a sidewall; a second region; and a first isolation track comprising a first region And an electrode insulating layer between the second regions. The light emitting diode further comprises an electrode connecting layer covering the first region; an electrical connecting structure covering the second region; and an electrical connecting layer under the electrical connecting structure, and the electrical connecting layer directly contacting the electrical connecting structure The first region and the second region respectively comprise a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer, and the electrode connection layer covers the sidewall of the first region.

The embodiments of the present invention will be described in detail, and in the drawings, the same or the like

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 to 13. The structure and manufacturing steps of the LED array 1000 according to the first embodiment of the present invention are as follows: as shown in FIG. 1, a growth substrate 10 such as a gallium arsenide substrate is provided; and a plurality of light emitting diodes are directly epitaxially grown. On this substrate. In this embodiment, the number of the LED units is 100 and 200, but it is not limited to this number. Each of the light emitting diodes includes a first conductive type contact layer 11, a first conductive type semiconductor layer 12, an active layer 13, and a second conductive type semiconductor layer 14, as shown in FIG. 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 have one or a kind of material. The above elements are selected from the group consisting of gallium (Ga), aluminum (Al), indium (In), arsenic (As), phosphorus (P), nitrogen (N), and cerium (Si); for example, gallium phosphide (GaP) or aluminum gallium indium phosphide (AlGaInP).

An electrode structure is formed on the second conductive semiconductor layer 14 by a vapor deposition method in a selective region, for example, at least one second electrical electrode 15b and a plurality of second electrical extension electrodes 15c. After bonding a temporary substrate 16 over the electrodes, the growth substrate 10 is removed, as shown in Figures 3 and 4; wherein the temporary substrate 16 can be glass. The first conductive type contact layer 11 is partially removed by a photolithography etching process to form a plurality of dot structures and expose a portion of the lower surface 12a of the first conductive type semiconductor layer 12, and then to the partial lower surface 12a and the plurality of An electrically conductive layer 17 is formed under the dot structure of a conductive type contact layer 11 as shown in FIG. The material of the second electrical electrode 15b and the plurality of second electrical extension electrodes 15c may be selected from the group consisting of chromium (Cr), titanium (Ti), nickel (Ni), platinum (Pt), copper (Cu), and gold ( Metal materials such as Au), aluminum (Al), tungsten (W), tin (Sn), or silver (Ag). The material of the electrical connection layer 17 may be ruthenium/gold.

The lower surface 12a of the first conductive type semiconductor layer 12 is etched into a rough plane by wet etching as shown in Fig. 6. Further, a permanent substrate 18 such as an aluminum oxide substrate is provided; and a bonding layer 19 is formed on the substrate to form a structure as 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 to the lower surface 12a of the first conductive semiconductor layer 12 by the bonding layer 19, so that the structures of the sixth and seventh structures are joined together, and a plurality of A conductive contact layer dot 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 electrode 15b, the plurality of second electrical extension electrodes 15c, and a portion of the upper surface 14a of the second conductivity type semiconductor layer 14, as shown in FIG. The second conductive type semiconductor layer 14 and the active layer 13 are dry-etched from the top to the bottom to expose a portion of the surface of the first conductive type semiconductor layer 12 to form a surface by an Inductively Coupled Plasma Reactive Ion Etching System. The first insulating track 20 and the second insulating track 21; wherein the first insulating track 20 divides the first light emitting diode 100 into a first region 50A and a second region 50B, and the distance between the two regions is not less than 25 μm. . The second isolation track 21 is located between the first light emitting diode 100 and the second light emitting diode 200. The upper surface 14a of the second conductive type semiconductor layer 14 is then etched into a rough plane by dry etching or wet etching, as shown in FIG. A portion of the first conductive semiconductor layer 12 in the second isolation track 21 is etched and removed again by an inductively coupled plasma ion etching system. The sidewalls of the second conductive type semiconductor layer 14, the active layer 13, and the first conductive type semiconductor layer 12 in the second isolation track 21 are formed in a step shape due to the difference in the secondary dry etching rate before and after, as shown in FIG.

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

FIG. 13 is a top view of a light-emitting diode array 2000 according to a second embodiment of the present invention, which includes a total of 10 light-emitting diodes including a first light-emitting diode 100 and a second light-emitting diode 200, and is electrically connected to each other. A series of light emitting diodes connected in series. As shown in FIG. 13, the LED array 2000 includes a substrate 30 having a first surface 30a. The ten LEDs are located on the first surface, and include a first LED and a second LED. a plurality of conductive wiring structures 40 are disposed on the first surface, electrically connected to the light emitting diodes; the second electrical solder pads 50, 60 are located on the first surface, and the second electrical solder pads and the first An external power supply is electrically connected (not shown); an isolation channel 70 is located between any of the electrical solder pads (eg, solder pads 50) and any of the light emitting diodes (eg, the light emitting diode 100); The distance between the electric solder pad and the light emitting diode is not less than 25 μm. When the distance between the electrical soldering pad and the light-emitting diode is too small, semiconductor material is likely to remain on the sidewall of the light-emitting diode during the etching step of the light-emitting diode, causing leakage. At this time, an electrode insulating layer 80 is formed on the sidewall of the light-emitting diode in the insulating track 70, which can improve the phenomenon. The substrate 30 is a carrier base and may include a conductive substrate or a non-conductive substrate, a light-transmitting substrate or an opaque substrate.

The first conductive type semiconductor layer 12 and the second conductive type semiconductor layer 14 are different in electrical conductivity, polarity, or dopant of at least two portions of each other, or are used to provide a single layer of a semiconductor material for electrons and holes, respectively. Or a plurality of layers ("multilayer" means two or more layers, the same applies hereinafter), and the electrical selection may 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 conductive type semiconductor layer 12 and the second conductive type semiconductor layer 14 and is a region where electrical energy and light energy may be converted or induced to be converted.

The light-emitting spectrum of the light-emitting diode according to the embodiment of the present invention can be adjusted by changing the physical or chemical elements of the semiconductor single layer or layers. Commonly used materials are such as aluminum gallium indium phosphide (AlGaInP) series, aluminum gallium indium nitride (AlGaInN) series, zinc oxide (ZnO) series and the like. 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 wavelength of the illumination.

In one embodiment of the present invention, a buffer layer (not shown) is further disposed between the first conductive type contact layer 11 and the growth substrate 10. The buffer layer is interposed between the two material systems to "transition" the material system of the substrate to the material system of the semiconductor system. For the structure of the light-emitting diode, on the one hand, the buffer layer is used to reduce the material layer of the lattice mismatch between the two materials. On the other hand, the buffer layer may also be a single layer, a plurality of layers or a structure for combining two materials or two bifurcation structures, such as organic materials, inorganic materials, metals, and semiconductors; The selected structure is: reflective layer, thermally conductive layer, conductive layer, anti-deformation layer, stress release layer, stress adjustment layer, bonding layer, wavelength conversion layer, and mechanical fixing structure Wait. In one embodiment, the material of the buffer layer may be AlN, GaN, GaInP, InP, GaAs, AlAs, and the formation method may be sputtering or atomic layer deposition (ALD).

A second conductive type contact layer (not shown) is more selectively formed on the second conductive type semiconductor layer 14. The contact layer is disposed on one side of the second conductive type semiconductor layer from the side of the active layer 13. Specifically, the second conductive type contact layer may be an optical layer, an electrical layer, or a combination of both. The optical layer can alter the electromagnetic radiation or light from or into the active layer (not shown). As used herein, "change" refers to altering at least one optical property of electromagnetic radiation or light, including but not limited to frequency, wavelength, intensity, flux, efficiency, color temperature, rendering index, light field. (light field), and angle of view. The electrical layer layer may cause a change, or a change in the value, density, and distribution of at least one of voltage, resistance, current, and capacitance between opposite sides of any one of the second conductive type contact layers. The constituent material of the second conductive type contact layer contains an oxide, a conductive oxide, a transparent oxide, an oxide having a transmittance of 50% or more, a metal, a relatively light-transmitting metal, and a transmittance of 50% or more. At least one of a metal, an organic substance, an inorganic substance, a fluorescent substance, a phosphor, a ceramic, a semiconductor, a doped semiconductor, and an 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. In the case of a relatively light-transmissive metal, the thickness is about 0.005 μm to 0.6 μm.

The above figures and descriptions are only corresponding to specific embodiments, however, the elements, embodiments, design criteria, and technical principles described or disclosed in the various embodiments are inconsistent, contradictory, or difficult to implement together. In addition, we may use any reference, exchange, collocation, coordination, or merger as required.

Although the invention has been described above, it is not intended to limit the scope of the invention, the order of implementation, or the materials and process methods used. Various modifications and variations of the present invention are possible without departing from the spirit and scope of the invention.

1‧‧‧Package structure
2‧‧‧Light Emitter Wafer
3‧‧‧pn junction
4‧‧‧welding line
5,6‧‧‧conductive bracket
10‧‧‧ Growth substrate
11‧‧‧First Conductive Contact Layer
12‧‧‧First Conductive Semiconductor Layer
12a‧‧‧ lower plane
13‧‧‧Active layer
14‧‧‧Second conductive 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‧‧‧Connection layer
20‧‧‧First isolation road
21‧‧‧Second isolation road
22‧‧‧Electrode insulation
23‧‧‧Insulation structure
24‧‧‧Electrical connection structure
25‧‧‧Second electric solder pad
26‧‧‧Electrode connection layer
30‧‧‧Substrate
30a‧‧‧ first surface
40‧‧‧ Conductive wiring structure
50,60‧‧‧Electric solder pads
50A‧‧‧First Area
50B‧‧‧Second area
70‧‧ ‧isolate
80‧‧‧electrode insulation
100‧‧‧first light-emitting diode
200‧‧‧Second light-emitting diode
300‧‧‧Light Emitter Package
1000, 2000‧‧‧Light emitting diode array

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

Figure 13 is a top view of an array of light-emitting diodes of a second embodiment of the present invention.

Fig. 14 is a structural diagram of a conventional light-emitting element.

11‧‧‧First Conductive Contact Layer

12‧‧‧First Conductive Semiconductor Layer

12a‧‧‧ lower plane

13‧‧‧Active layer

14‧‧‧Second conductive semiconductor layer

14a‧‧‧Upper plane

15b‧‧‧Second electrical electrode

15c‧‧‧Second electrical extension electrode

17‧‧‧Electrical connection layer

18‧‧‧Permanent substrate

19‧‧‧Connection layer

20‧‧‧First isolation road

21‧‧‧Second isolation road

22‧‧‧Electrode insulation

23‧‧‧Insulation structure

24‧‧‧Electrical connection structure

25‧‧‧Second electric solder pad

26‧‧‧Electrode connection layer

100‧‧‧first light-emitting diode

50A‧‧‧First Area

50B‧‧‧Second area

200‧‧‧Second light-emitting diode

1000‧‧‧Lighting diode array

Claims (10)

a light emitting diode comprising: a first light emitting diode structure comprising: a first region comprising a sidewall; a second region; and a first isolation track comprising a first region and An electrode insulation layer between the second regions, wherein the sidewall of the first region is located in the first isolation track; an electrode connection layer covers the sidewall of the first region, the electrode connection layer is separated from the electrode insulation layer An electrical connection structure covers the second region; and an electrical connection layer 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 of the regions includes a first conductive semiconductor layer, an active layer, and a second conductive semiconductor layer. The illuminating diode of claim 1, further comprising a second illuminating diode structure, the second illuminating diode structure comprising a semiconductor stack and a semiconductor stack And a solder pad, wherein the semiconductor stack comprises a first conductive semiconductor layer, an active layer and a second conductive semiconductor layer. The light-emitting diode of claim 2, further comprising a second isolation track between the first light-emitting diode structure and the second light-emitting diode structure, the electrical connection structure And extending in the second isolation track and electrically connecting the first light emitting diode structure and the second light emitting diode structure. The light-emitting diode according to claim 3, further comprising a first insulating structure and a second insulating structure in the second insulating track. The light-emitting diode of claim 4, wherein the electrical connection structure separates the first insulation structure and the second insulation structure in a cross-sectional view of the light-emitting diode. The light-emitting diode of claim 4, wherein the electrical connection structure covers the first insulation structure. The illuminating diode of claim 3, wherein the second quarantine channel separates the second conductive semiconductor layer of the second region from the second conductive semiconductor of the second luminescent diode structure a layer, the active layer separating the active layer and the second light emitting diode structure, and the first conductive type semiconductor layer and the second light emitting diode structure separating the second region A conductive semiconductor layer. The light-emitting diode according to claim 1, wherein a distance between the first region and the second region is not less than 25 micrometers (μm). The light-emitting diode of claim 1, wherein the first conductive semiconductor layer of the first region is connected to the first conductive semiconductor layer of the second region. The light-emitting diode of claim 1, wherein the first conductive semiconductor layer of the first region has an upper surface and a sidewall located on the first isolation track, the activity of the first region The layer has a sidewall on the first isolation track, the electrode connection layer covering the upper surface of the first conductive semiconductor layer and extending in the first isolation track to cover the second conductivity type of the first region The sidewall of the semiconductor layer and the sidewall of the active layer overlying the first region.