semiconductor elements

Abstract

To provide a semiconductor element that improves the luminous efficiency, uneven light emission, and color unevenness caused by the non-uniform current distribution in light emitting diodes, thereby enhancing the brightness of the light emitting diodes.SOLUTION: The present invention relates to a semiconductor element comprising a substrate 10, an upper electrode 50, a first semiconductor layer 20, a light emitting layer 30, a second semiconductor layer 40, and a plurality of conductive through holes 26. The second semiconductor layer, the light emitting layer, the first semiconductor layer, and the upper electrode are sequentially arranged on the substrate. These conductive through holes are formed vertically in the first semiconductor layer. The upper electrode is electrically connected to the light emitting layer via these conductive through holes.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to semiconductor devices, and more particularly to light emitting diodes with uniform current spreading. [Background technology]

[0002] Light-emitting diodes (LEDs), a type of solid-state light-emitting device, have advantages such as low power consumption, low heat generation, long life, drop resistance, small size, fast response, good photoelectric properties, and stable emission wavelength, and are therefore widely used in home appliances, display lamps, optoelectronic products, etc. With the development of optoelectronic technology, the luminous efficiency, operating life, and brightness of solid-state light-emitting devices have improved significantly, making light-emitting diodes the mainstream of future lighting devices.

[0003] Light-emitting diodes function by applying a voltage between two different types of semiconductor materials, directing electrons and holes into the PN junction region. Current spreading allows carriers to move from high-concentration regions to low-concentration regions, achieving effective carrier injection. When electrons and holes are injected into the PN junction region, they combine in this region. The combination process releases energy, which is what causes the LED to emit light. Current spreading allows many electrons and holes to meet in the light-emitting region, increasing the chances of carrier combination and improving light-emitting efficiency. If the carrier density is not uniform, only some areas will emit light, resulting in uneven lighting and color variation.

[0004] In order to overcome the above problems, it has become an urgent task in the industry to develop an innovative light emitting diode structure that can improve the problem of poor current spreading and increase the brightness of the light emitting diode. Summary of the Invention

[0005] The main object of the present invention is to provide an innovative semiconductor device that improves the brightness of light-emitting diodes by solving the problems of reduced light-emitting efficiency, uneven light emission, and uneven color caused by uneven current distribution in conventional light-emitting diodes.

[0006] To achieve the above object, the present invention provides a semiconductor device comprising a substrate, an upper electrode, a first semiconductor layer, a light-emitting layer, a second semiconductor layer, and a plurality of conductive through-holes. The second semiconductor layer, the light-emitting layer, the first semiconductor layer, and the upper electrode are sequentially arranged on the substrate. The conductive through-holes are provided vertically in the first semiconductor layer. The upper electrode is electrically connected to the light-emitting layer via the conductive through-holes.

[0007] In an embodiment of the present invention, the upper electrode is electrically connected to the light-emitting layer through a conductive through-hole.

[0008] In an embodiment of the present invention, the semiconductor device further comprises a current spreading composite layer disposed within the first semiconductor layer, and the conductive through-holes pass through the current spreading composite layer in the vertical direction.

[0009] In an embodiment of the present invention, the conductive through holes are arranged vertically in the edge region or the inner region of the first semiconductor layer.

[0010] In an embodiment of the present invention, these conductive through holes include a conductive film covering the surface of the conductive through holes.

[0011] In an embodiment of the present invention, the conductive film is a metal thin film, and the material of the metal thin film is one selected from the group consisting of beryllium (Be), gold (Au), aluminum (Al), platinum (Pt), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), chromium (Cr), and titanium (Ti), or a combination thereof.

[0012] In an embodiment of the present invention, the conductive film is a transparent conductive film, and the material of the transparent conductive film is one selected from the group consisting of indium tin oxide (ITO), aluminum zinc oxide (AZO), zinc tin oxide (IZO), zinc oxide (ZnO), nickel oxide, indium tin oxide, cadmium tin oxide, and antimony tin oxide, or a combination thereof.

[0013] In an embodiment of the present invention, the conductive film includes an ion-implanted film, and the ion-implanted material of the ion-implanted film is one selected from the group consisting of silicon (Si), tellurium (Te), antimony (Sb), magnesium (Mg), zinc (Zn), and copper (Cu), or a combination thereof.

[0014] In an embodiment of the present invention, the current spreading composite layer includes at least one pair of a doped layer and an undoped layer stacked one above the other.

[0015] In an embodiment of the present invention, the doped layer of the current spreading composite layer is doped aluminum gallium indium phosphide (Al x Ga (0.5-x) In 0.5 P) layer, x=0.05 to 0.45, doped aluminum gallium indium phosphide layer is 1.0E17 / cm 3 ~2.0E19 / cm 3 The silicon or tellurium doped silicon nitride has a doping concentration of 0.15 to 0.25.

[0016] In an embodiment of the present invention, the undoped layer of the current spreading composite layer is undoped aluminum gallium indium phosphide (Al y Ga (0.5-y) In 0.5 P) layer, and y ≥ x.

[0017] In an embodiment of the present invention, the total thickness of the current spreading composite layer is about 0.1 to 3 micrometers (μm), the thickness of the doped aluminum gallium indium phosphide layer is about 50 to 5000 angstroms (Å), and the thickness of the undoped aluminum gallium indium phosphide layer is about 50 to 5000 angstroms (Å).

[0018] In an embodiment of the present invention, the materials of the first semiconductor layer, the light emitting layer, and the second semiconductor layer are one selected from the group consisting of indium gallium phosphide (InGaP), aluminum gallium indium phosphide (AlGaInP), aluminum indium phosphide (AlInP), indium gallium arsenide (InGaAs), aluminum indium gallium arsenide (AlInGaAs), aluminum gallium arsenide (AlGaAsP), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), and indium gallium arsenide phosphide (InGaAsP), or a combination thereof.

[0019] In an embodiment of the present invention, the semiconductor element further includes a plurality of dot-shaped conductive electrodes, which are arranged on the insulating dielectric layer at the bottom of the second semiconductor layer so as not to overlap the conductive through-holes in the vertical direction.

[0020] Those skilled in the art can understand other objects of the present invention, as well as the technical means and embodiments of the present invention, by referring to the drawings and the embodiments described below. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic diagram showing a light-emitting diode according to an embodiment of the present invention; [Figure 2] Schematic top view of the light-emitting diode of Figure 1 [Figure 3] FIG. 1 is a schematic diagram showing a light-emitting diode according to another embodiment of the present invention; [Figure 4] FIG. 1 is a partially enlarged schematic view of a light-emitting diode according to an embodiment of the present invention. [Figure 5] FIG. 1 is a schematic diagram showing a light-emitting diode according to another embodiment of the present invention; [Figure 6] 6 is a top view of the light-emitting diode shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described below through examples. Note that the examples of the present invention are merely examples of embodiments and are not intended to limit the present invention to the environments, applications, or specific aspects described in the examples. Therefore, the explanation of the examples is intended to explain the present invention, but does not limit the present invention. Note that components not directly related to the present invention are omitted and not shown in the embodiments and drawings. The dimensional relationships between the components in the drawings are intended to facilitate understanding and do not limit the actual dimensions.

[0023] FIG. 1 illustrates an embodiment of a semiconductor device according to the present invention. FIG. 1 is a schematic diagram illustrating the structure of a light-emitting diode with uniform current diffusion. As shown in FIG. 1, in this embodiment, the light-emitting diode includes a substrate 10, a first semiconductor layer 20, a light-emitting layer 30, a second semiconductor layer 40, an upper electrode 50, and a lower electrode 60. The second semiconductor layer 40, the light-emitting layer 30, the first semiconductor layer 20, and the upper electrode 50 are sequentially disposed on the substrate 10. Meanwhile, the lower electrode 60 is disposed on the opposite side of the substrate 10. In this embodiment, the substrate 10 is a semiconductor substrate such as, but not limited to, a silicon substrate, a silicon carbide substrate, an aluminum nitride substrate, a sapphire substrate, a gallium arsenide substrate, a gallium phosphide substrate, or an indium phosphide substrate. The first semiconductor layer 20, the light emitting layer 30, and the second semiconductor layer 40 are a semiconductor epitaxial structure arranged on the substrate 10, and the material constituting this epitaxial structure is one selected from the group consisting of indium gallium phosphide (InGaP), aluminum gallium indium phosphide (AlGaInP), aluminum indium phosphide (AlInP), indium gallium arsenide (InGaAs), aluminum indium gallium arsenide (AlInGaAs), aluminum gallium arsenide (AlGaAs), aluminum gallium arsenide phosphide (AlGaAsP), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), and indium gallium arsenide phosphide (InGaAsP), or a combination thereof.

[0024] 1, in a specific embodiment, the second semiconductor layer 40 is a P-type semiconductor layer disposed on the substrate 10. For example, the second semiconductor layer 40 is an aluminum gallium indium phosphide layer, Al x Ga (0.5-x) In 0.5 P, and x=0 to 0.5, but not limited thereto. The doping element is magnesium (Mg) or zinc (Zn), and the doping concentration is about 1.0E16 / cm 3 ~1.0E20 / cm 3 The thickness of the second semiconductor layer 40 is, but is not limited to, 100 to 100,000 angstroms (Å). The light emitting layer 30 has a multiple quantum well (MQW) structure. In this embodiment, the multiple quantum well emits light at a wavelength of, but is not limited to, 600 to 700 nanometers.

[0025] On the other hand, the first semiconductor layer 20 is an N-type semiconductor. In a preferred embodiment, the first semiconductor layer 20 includes a first semiconductor upper layer 22, a first semiconductor lower layer 24, and a plurality of conductive through holes 26. The first semiconductor upper layer 22 is an aluminum gallium indium phosphide layer, and the Al x Ga (0.5-x) In 0.5 P, and x=0.05 to 0.45, but not limited thereto. The doping element is silicon (Si) or tellurium (Te), and the doping concentration is about 1.0E17 / cm 3 ~2.0E19 / cm 3 The thickness of the first semiconductor upper layer 22 is 100 to 100,000 angstroms (Å), but is not limited to this. The first semiconductor lower layer 24 is an aluminum gallium indium phosphide layer, and x Ga (0.5-x) In 0.5 P, and x=0.05 to 0.5, but not limited thereto. The doping element is silicon (Si) or tellurium (Te), and the doping concentration is about 1.0E17 / cm 3 ~2.0E19 / cm3 The thickness of the first semiconductor lower layer 24 is in the range of 100 to 100,000 angstroms (Å), but is not limited to this.

[0026] In addition, in the prior art, the upper electrode of an LED typically has a finger-shaped branched electrode to achieve the goals of current spreading and brightness enhancement. This allows current to be evenly injected into the light-emitting layer, increasing brightness. However, because electrodes are typically made of metal, the excessive branching structure of the finger-shaped electrode blocks light, hindering light extraction and resulting in reduced brightness. In light of this, a feature of the present invention is that the upper electrode 50 has a fingerless design. That is, instead of the aforementioned finger-shaped branched electrode, the present invention utilizes a pin-shaped electrode with multiple conductive through-holes. As shown in FIG. 1, multiple conductive through-holes 26 are arranged from top to bottom around the periphery of the upper electrode 50. The conductive through-holes 26 are uniformly distributed throughout the first semiconductor layer 20.

[0027] More specifically, each conductive through-hole 26 penetrates vertically from the first semiconductor upper layer 22 to the first semiconductor lower layer 24. Therefore, an external current applied to the upper electrode 50 flows from the first semiconductor upper layer 22 to the first semiconductor lower layer 24 via these conductive through-holes 26 and reaches the light-emitting layer 30. To achieve current diffusion, the above-mentioned multiple conductive through-holes 26 are uniformly arranged in the first semiconductor layer 20, as shown in FIG. 2. FIG. 2 is a top view schematic diagram of the light-emitting diode of FIG. 1. FIG. 1 is a cross-sectional view of the light-emitting diode structure taken along the BB' cross-section line in FIG. 2. The conductive through-holes 26 may have a circular, elliptical, rectangular, or other shape, but are not limited thereto. The conductive through-holes 26 are distributed throughout the inner region of the first semiconductor layer 20 of the light-emitting diode. Alternatively, as shown in FIG. 3, the conductive through-holes 26 may be arranged in the edge region of the first semiconductor layer 20 of the light-emitting diode to achieve uniform current diffusion. The conductive through holes distributed in the inner region of the light-emitting diode and the conductive through holes distributed in the edge region of the light-emitting diode can replace the branched structure of the finger-shaped electrode of the conventional light-emitting diode, so that the present invention can effectively reduce the light-shielding area of ​​the upper electrode and improve the light extraction efficiency.

[0028] Specifically, each conductive through hole 26 has a conductive film 261. The conductive film 261 covers the surface of each conductive through hole and the outer periphery of the upper electrode 50 of the light-emitting diode. For example, the conductive film 261 is a transparent conductive film. The material of the transparent conductive film is one selected from the group consisting of indium tin oxide (ITO), aluminum zinc oxide (AZO), zinc tin oxide (IZO), zinc oxide (ZnO), nickel oxide, indium tin oxide, cadmium tin oxide, and antimony tin oxide, or a combination thereof. The conductive film 261 may also be a metal thin film. The material of the metal thin film is one selected from the group consisting of beryllium (Be), gold (Au), aluminum (Al), platinum (Pt), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), chromium (Cr), and titanium (Ti), or a combination thereof. In other embodiments, the conductive film 261 may include an ion-implanted film or a conductive region formed by diffusion. The ion-implanted material of the ion-implanted film may be one or a combination of silicon (Si), tellurium (Te), antimony (Sb), magnesium (Mg), zinc (Zn), and copper (Cu).

[0029] Preferably, as shown in FIGS. 1 and 4, the first semiconductor layer 20 further includes a current spreading composite layer 28 disposed between the first semiconductor upper layer 22 and the first semiconductor lower layer 24. Furthermore, the above-mentioned conductive through-holes 26 have a depth that at least penetrates the current spreading composite layer 28, thereby electrically connecting the first semiconductor upper layer 22 to the first semiconductor lower layer 24. As shown in FIG. 4, the current spreading composite layer 28 of the light-emitting diode of the present invention includes at least one pair of a doped layer 281 and an undoped layer 282 stacked one above the other. Specifically, in the current spreading composite layer 28 of the illustrated embodiment, the doped layers 281 disposed in the odd-numbered layers (1st, 3rd, 5th, ... layers) are doped with aluminum gallium indium phosphide (Al x Ga (0.5-x) In 0.5The doped aluminum gallium indium phosphide layer is doped with silicon (Si) or tellurium (Te), and the doping concentration is 1.0E17 / cm 3 ~2.0E19 / cm 3 The thickness of the doped layer 281 is 50 to 5000 angstroms (Å), but is not limited to this. On the other hand, the undoped layers 282 arranged in the even-numbered layers (2nd, 4th, 6th, etc. layers) are made of undoped aluminum gallium indium phosphide (Al y Ga (0.5-y) In 0.5 P) layer, where y≧x. The thickness of the undoped layer 282 is 50 to 5000 angstroms (Å), but is not limited to this. The total thickness of the current spreading composite layer 28 is approximately 0.1 to 3 micrometers (μm).

[0030] As mentioned above, the resistance of the current spreading layer is related to the doping concentration, the thickness of the semiconductor layer, and the material composition. Therefore, by appropriately controlling each of the above-mentioned influencing factors, it is possible to efficiently pass current through the semiconductor layer and achieve uniform current spreading. For example, the higher the doping concentration, the lower the resistance. Furthermore, the thicker the doped layer, the lower the resistance. Therefore, reducing the resistance of the doped layer to guide current can have the effect of enhancing lateral conduction. Meanwhile, the lower the aluminum content in the aluminum gallium indium phosphide layer, the lower the resistance. On the other hand, an undoped semiconductor layer has a much lower carrier concentration than a doped semiconductor, and therefore its conductivity is closer to that of an insulator. The thicker the undoped semiconductor layer, the higher the resistance. The higher the aluminum content in the aluminum gallium indium phosphide layer, the higher the resistance. Therefore, by enhancing the insulating effect of the undoped layer, a vertical current blocking effect can be achieved, allowing current to flow horizontally. In summary, in order to achieve a uniform current spreading effect and improve the brightness of the light emitting diode, the present invention arranges multiple current spreading layers on top of and below the N-type semiconductor, and alternately stacks highly doped semiconductor layers and undoped semiconductor layers, thereby achieving the effects of strengthening lateral current conduction in the doped layers and enhancing the vertical current blocking effect in the undoped layers.

[0031] The doping concentration and thickness values ​​of each layer of the current spreading layer described above are merely examples and are not limited thereto. In the present invention, there are no particular limitations on the doping element, doping concentration, or thickness. To achieve a difference in actual resistance, it is sufficient to have a difference in doping concentration between adjacent diffusion layers above and below. This achieves a "vertical blocking, lateral enhancement" diffusion effect between each layer. After passing through the current spreading layer, the current is uniformly spread before being injected into the light-emitting layer 30.

[0032] The following description will be given with reference to FIGS. 5 and 6. FIG. 5 illustrates another embodiment of a light-emitting diode according to the present invention. Unlike the previous embodiments, the light-emitting diode of this embodiment includes an electrically insulating dielectric layer 42 and a reflective metal layer 44 disposed at the bottom of the second semiconductor layer 40 to enhance current diffusion and light extraction efficiency. The dielectric layer 42 and the reflective metal layer 44 reflect light generated from the light-emitting layer 30 upward, improving brightness. Furthermore, the dielectric layer 42 includes a plurality of ohmic contact dot-shaped conductive electrodes 46 for conducting current to the lower electrode. The dot-shaped conductive electrodes 46 are arranged around the upper electrode 50 in a dot-like or stripe-like pattern. As shown in FIG. 6, these dot-shaped conductive electrodes 46 do not vertically overlap the conductive through-holes 26, thereby enabling more uniform current diffusion and achieving the goal of improved brightness.

[0033] The above examples are intended to explain embodiments of the present invention and to explain the characteristic configurations of the present invention. The present invention is not limited to the above examples. Modifications or equivalent arrangements that can be easily made by those skilled in the art are also within the scope of the present invention. The scope of protection of the rights of the present invention is based on the claims. [Explanation of symbols]

[0034] 10 Substrate 20 First semiconductor layer 22 First semiconductor upper layer 24 First semiconductor lower layer 26 Conductive through hole 261 Conductive Film 28 Current Diffusion Composite Layer 281 Doped Layer 282 Undoped Layer 30 Light-emitting layer 40 Second semiconductor layer 42 Dielectric Layer 44 Reflective metal layer 46 Dot-shaped conductive electrode 50 Upper electrode 60 Lower electrode

Claims

1. A semiconductor device, A substrate; an upper electrode; a first semiconductor layer; a light-emitting layer; a second semiconductor layer; a plurality of conductive through holes; the second semiconductor layer, the light emitting layer, the first semiconductor layer, and the upper electrode are sequentially disposed on the substrate; the conductive through hole is provided in the first semiconductor layer in a vertical direction, a current spreading composite layer disposed within the first semiconductor layer; The semiconductor device, wherein the conductive through-holes penetrate the current spreading composite layer in the vertical direction.

2. The semiconductor device according to claim 1 , wherein the upper electrode is electrically connected to the light-emitting layer through the conductive through-hole.

3. The semiconductor device according to claim 1 , wherein the conductive through-hole is disposed vertically in an edge region or an inner region of the first semiconductor layer.

4. The semiconductor device according to claim 1 , wherein the conductive through-hole includes a conductive film covering a surface of the conductive through-hole.

5. 5. The semiconductor device of claim 4, wherein the conductive film is a metal thin film, and the material of the metal thin film is one selected from the group consisting of beryllium (Be), gold (Au), aluminum (Al), platinum (Pt), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), chromium (Cr), and titanium (Ti), or a combination thereof.

6. 5. The semiconductor device according to claim 4, wherein the conductive film is a transparent conductive film, and the material of the transparent conductive film is one selected from the group consisting of indium tin oxide (ITO), aluminum zinc oxide (AZO), zinc tin oxide (IZO), zinc oxide (ZNO), nickel oxide, indium tin oxide, cadmium tin oxide, and antimony tin oxide, or a combination thereof.

7. A semiconductor element, A substrate; an upper electrode; a first semiconductor layer; a light-emitting layer; a second semiconductor layer; a plurality of conductive through holes; the second semiconductor layer, the light emitting layer, the first semiconductor layer, and the upper electrode are sequentially disposed on the substrate; the conductive through hole is provided in the first semiconductor layer in a vertical direction, the conductive through-hole includes a conductive film covering a surface of the conductive through-hole, The conductive film includes an ion-implanted film, and the ion-implanted material of the ion-implanted film is one selected from the group consisting of silicon (Si), tellurium (Te), antimony (Sb), magnesium (Mg), zinc (Zn), and copper (Cu), or a combination thereof.

8. 2. The semiconductor device according to claim 1, wherein the current spreading composite layer comprises at least one pair of a doped layer and an undoped layer stacked one above the other.

9. The doped layer of the current spreading composite layer is doped aluminum gallium indium phosphide (Al ｘ Ga （０．５－ｘ） In ０．５ P) layer, x=0.05 to 0.45, and the doped aluminum gallium indium phosphide layer has a doping density of 1.0E17 / cm ３ ~2.0E19 / cm ３ 9. The semiconductor device according to claim 8, wherein the semiconductor device is doped with silicon or tellurium at a doping concentration of 0.1 to 0.

5.

10. The undoped layer of the current spreading composite layer is undoped aluminum gallium indium phosphide (Al ｙ Ga （０．５－ｙ） In ０．５ 10. The semiconductor device according to claim 9, wherein the n-type n-type layer is a n-type p-type layer, and y≧x.

11. 11. The semiconductor device of claim 10, wherein the current spreading composite layer has a total thickness of about 0.1 to 3 micrometers (μm), the doped aluminum gallium indium phosphide layer has a thickness of about 50 to 5000 angstroms (Å), and the undoped aluminum gallium indium phosphide layer has a thickness of about 50 to 5000 angstroms (Å).

12. A semiconductor device comprising: A substrate; an upper electrode; a first semiconductor layer; a light-emitting layer; a second semiconductor layer; a plurality of conductive through holes; the second semiconductor layer, the light emitting layer, the first semiconductor layer, and the upper electrode are sequentially disposed on the substrate; the conductive through hole is provided in the first semiconductor layer in a vertical direction, a semiconductor element, characterized in that the materials of the first semiconductor layer, the light-emitting layer, and the second semiconductor layer are one selected from the group consisting of indium gallium phosphide (InGaP), aluminum gallium indium phosphide (AlGaInP), aluminum indium phosphide (AlInP), indium gallium arsenide (InGaAs), aluminum indium gallium arsenide (AlInGaAs), aluminum gallium arsenide phosphide (AlGaAsP), gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP), and indium gallium arsenide phosphide (InGaAsP), 13. A semiconductor device comprising: A substrate; an upper electrode; a first semiconductor layer; a light-emitting layer; a second semiconductor layer; a plurality of conductive through holes; the second semiconductor layer, the light emitting layer, the first semiconductor layer, and the upper electrode are sequentially disposed on the substrate; the conductive through hole is provided in the first semiconductor layer in a vertical direction, 10. A semiconductor device, further comprising: a plurality of dot-shaped conductive electrodes, the dot-shaped conductive electrodes being disposed on the second semiconductor layer so as not to overlap the conductive through-holes in a vertical direction.

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