CN216354258U

CN216354258U - Semiconductor light-emitting element

Info

Publication number: CN216354258U
Application number: CN202123032410.9U
Authority: CN
Inventors: 徐胜娟; 徐凯; 张克旺; 黄照明; 蔡家豪
Original assignee: Anhui Sanan Optoelectronics Co Ltd
Current assignee: Anhui Sanan Optoelectronics Co Ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-04-19
Anticipated expiration: 2031-11-30

Abstract

The utility model belongs to the field of semiconductors, and particularly relates to a semiconductor light-emitting element, which comprises: a substrate; the light-emitting diode comprises a first semiconductor layer, a light-emitting layer, a second semiconductor layer, a transparent conductive layer, a first insulating layer, a first electrode and a second electrode which are sequentially stacked on the substrate, wherein the first electrode comprises a first bonding pad and a first expansion part and is connected with the first semiconductor layer; the second electrode comprises a second bonding pad and a second extension part and is connected with the second semiconductor layer, the second extension part is formed above the first extension part, a second insulating layer is arranged between the first extension part and the second extension part, the second extension part comprises a main extension part and a sub-extension part connected with the main extension part, and the main extension part and the first extension part are located on the same vertical line. The utility model can reduce the shielding and absorption of the expansion part to light, so that the current expansion is more uniform, and the brightness of the light-emitting element is improved.

Description

Semiconductor light-emitting element

Technical Field

The utility model belongs to the field of semiconductors, and particularly relates to a semiconductor light-emitting element.

Background

A Light Emitting Diode (LED) is a semiconductor Light Emitting element, which is manufactured by using a semiconductor PN junction injection type electroluminescence principle. The LED has the characteristics of energy conservation, environmental protection, safety, durability, high photoelectric conversion rate, strong controllability and the like, and is widely applied to relevant fields such as illumination, household appliances, display screens, indicator lamps and the like at present.

The light emitting diode in the prior art is composed of a substrate, a P-type semiconductor layer, a light emitting layer, an N-type semiconductor layer, a transparent conductive layer, an insulating layer and a metal electrode layer, wherein the metal electrode layer comprises a metal electrode and an expansion strip and is used for conducting and expanding current. Normally, the larger the area occupied by the P electrode and the expansion strip is, the better the electric conduction condition is. However, the P-electrode and the expansion bar occupy the area of the light emitting region and have opaque characteristics, so as to absorb and block the light emitted from the light emitting layer. Therefore, in the constant current state, the larger the area of the metal electrode and the spreading bar is, the lower the voltage thereof is, but the light emission luminance of the diode is affected.

Disclosure of Invention

In order to solve the above-mentioned technical problem, the present invention provides a semiconductor light emitting element including: a substrate; the light-emitting diode comprises a first semiconductor layer, a light-emitting layer, a second semiconductor layer, a transparent conducting layer, a first insulating layer, a first electrode and a second electrode which are sequentially stacked on the substrate, and is characterized in that the first electrode comprises a first bonding pad and a first extension part, wherein the first bonding pad is connected with the first semiconductor layer, the first extension part is formed on the first insulating layer, a first through hole extending to the first semiconductor layer is arranged below the first extension part, and the first extension part is connected with the first semiconductor layer through the first through hole; the second electrode comprises a second bonding pad and a second extension part, wherein the second bonding pad is connected with the second semiconductor layer, the second extension part is formed above the first extension part, a second insulating layer is arranged between the first extension part and the second extension part, the second extension part comprises a main extension part and a sub-extension part connected with the main extension part, the main extension part and the first extension part are located on the same vertical line, a second through hole extending to the transparent conductive layer is arranged below the sub-extension part, and the sub-extension part is connected with the second semiconductor layer through the second through hole and the transparent conductive layer.

Preferably, the sub-expansions are symmetrically or asymmetrically arranged on both sides of the main expansion.

Preferably, the distance between adjacent sub-expansions is 30 to 90 μm.

Preferably, the sub-expansions located at both sides of the main expansion are staggered.

Preferably, the angle A between the sub expansion part and the main expansion part is 30-150 degrees.

Preferably, the sub-expansions located on the same side of the main expansion are arranged in parallel or not.

Preferably, the length of the sub-expansion part is 20-80 μm.

Preferably, the sub-expansions have the same or different lengths.

Preferably, the length of the sub-expansion part is gradually reduced or gradually increased or the same from the second pad to the end of the main expansion part.

Preferably, the distance between adjacent sub-expansions is gradually reduced or gradually increased or the same from the second pad to the end of the main expansion.

The utility model improves the structure of the second expansion part, reduces the shielding and absorption of light by reducing the number of the main expansion parts and enabling the main expansion parts and the first expansion parts to be positioned in the same area, thereby improving the brightness of the light-emitting element, and meanwhile, the sub expansion parts are additionally arranged on the main expansion parts, thereby improving the current expansion capability, enabling the current expansion to be more uniform and realizing the effect of reducing the voltage.

Drawings

FIG. 1 is a schematic top view of a semiconductor light emitting device in the prior art.

FIG. 2 is a schematic top view of a semiconductor light emitting device according to one embodiment of the present invention.

FIG. 3 is a cross-sectional view of line M-M'.

FIG. 4 is a schematic top view of a semiconductor light emitting device according to the second embodiment of the present invention.

FIG. 5 is a schematic top view of a semiconductor light emitting device according to a third embodiment of the present invention.

Detailed Description

The following embodiments will explain the concept of the present invention along with the accompanying drawings, in which like or similar parts are designated by the same reference numerals, and in which the shape or thickness of elements may be enlarged or reduced. It is to be noted that elements not shown in the drawings or described in the specification may be in a form known to those skilled in the art.

In the following embodiments, terms used to indicate directions, such as "upper", "lower", "front", "rear", "left", and "right", refer to directions only in the drawings. Accordingly, the directional terminology is used for purposes of illustration and is in no way limiting.

Referring to fig. 1, the related art semiconductor light emitting element includes a substrate 1, an N-type semiconductor layer, a light emitting layer, a P-type semiconductor layer, a transparent conductive layer, an insulating layer, and an electrode layer. The electrode layer includes electrode and extension 4, and wherein, the extension 4 that the P electrode 2 connection set up sets up to two, and the extension 4 that the N electrode 3 is connected sets up to one, and these three extension 4 set up respectively in the region of difference, can promote the electric current expansion ability and reduce product voltage, but the shared area of extension 4 is great, and has light-tight characteristic, can shelter from and absorb the light that the luminescent layer sent to influence the luminance.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a semiconductor light emitting device which can reduce the voltage without affecting the light emitting luminance.

Specifically, referring to fig. 2 and 3, a semiconductor light emitting device according to an embodiment of the present invention includes: substrate 10, epitaxial layers, transparent conductive layer 50, insulating layers, and electrodes.

The substrate 10 may be made of a conductive material or an insulating material, and the material may be selected from any one or a combination of sapphire, SiC, GaAs, GaN, AlN, GaP, Si, and ZnO. In order to improve the light extraction efficiency of the substrate 10, the substrate may be patterned to form a series of concave-convex structures on the surface thereof. The present embodiment prefers a patterned sapphire substrate.

And the epitaxial layer is formed on the substrate 10 and sequentially comprises a first semiconductor layer 20, a light emitting layer 30 and a second semiconductor layer 40 from bottom to top. Here, the first semiconductor layer 20 and the second semiconductor layer 40 may each be formed by stacking a plurality of III-V compound semiconductor layers, which may be a single-layer structure or a multi-layer structure. The first semiconductor layer 20 may be doped with N-type impurities for supplying electrons. The N-type impurity includes silicon (Si), germanium (Ge), tin (Sn), tellurium (Te), oxygen (O), carbon (C), etc., and Si doping is preferable in this embodiment. The second semiconductor layer 40 may be doped with P-type impurities for providing holes. P-type impurities include magnesium (Mg), zinc (Zn), beryllium (Be), calcium (Ca), Mg doping is preferred in this embodiment. The light emitting layer 30 may be composed of quantum wells in which quantum well layers and quantum barrier layers are alternately stacked, and electrons and holes are recombined in the light emitting layer to emit light. The light emitting layer 30 may be a multiple quantum well structure.

The transparent conductive layer 50, which is formed on the second semiconductor layer 40, has high light transmittance and an ability to promote current spreading. The transparent conductive layer 50 may be selected from one or a combination of several of an indium tin oxide layer, a zinc indium tin oxide layer, an indium zinc oxide layer, a zinc tin oxide layer, a gallium indium oxide layer, and a gallium zinc oxide layer, and indium tin oxide is preferred in this embodiment.

The insulating layers include a first insulating layer 60 and a second insulating layer 61. The first insulating layer 60 is formed on the transparent conductive layer 50, and the second insulating layer 61 is disposed between the first electrode 70 and the second electrode 80. The material of the insulating layer may be one of silicon dioxide (SiO2), silicon nitride (SiN), and titanium dioxide (TiO 2).

The first electrode 70 includes a first pad 71 and a first expansion 72. One end of the first extension portion 72 is connected to the first pad 71, and the other end extends in a direction away from the first pad 71, wherein the first pad 71 is connected to the first semiconductor layer 20, the first extension portion 72 is formed on the first insulating layer 60, and a first through hole 73 extending to the first semiconductor layer 20 is disposed below the first extension portion 72. Specifically, the first pad 71 and the first via 73 each penetrate through the first insulating layer 60, the transparent conductive layer 50, the second semiconductor layer 40, and the light emitting layer 30, and do not penetrate through the first semiconductor layer 20. The first pad 71 is directly connected in contact with the first semiconductor layer 20, and the first extension 72 is connected to the first semiconductor layer 20 through the first via 73.

The second electrode 80 includes a second pad 81 and a second extension 82, and one end of the second extension 82 is connected to the second pad 81, and the other end extends in a direction away from the second pad 81. The second pad 81 is connected to the second semiconductor layer 40, the second extension 82 is formed above the first extension 72, the second insulating layer 61 is disposed between the first extension 72 and the second extension 82, the second extension 82 includes a main extension 821 and a plurality of sub extensions 822, the sub extensions 822 are connected to the main extension 821, and the sub extensions 822 extend outward from the main extension 821, so that the current spreading capability is improved, and the voltage reduction effect is achieved. The main extension portion 821 and the first extension portion 72 are located on the same vertical line, that is, the arrangement areas of the main extension portion 821 and the first extension portion 72 are overlapped, so that the influence area of the extension portion on light can be reduced, and the light emitting brightness of the semiconductor light emitting element is improved.

The second insulating layer 61 is disposed between the first extension portion 72 and the second extension portion 82, so as to effectively prevent the first electrode 70 and the second electrode 80 from being directly conducted, and improve the reliability of the semiconductor device. A second through hole 83 extending to the transparent conductive layer 50 is disposed below the sub-extension 822. Specifically, the second pad 81 passes through the second insulating layer 61, the first insulating layer 60, and the transparent conductive layer 50 in this order, so that the second pad 81 is directly connected in contact with the second semiconductor layer 40. The second via 83 sequentially penetrates the first insulating layer 60 and the second insulating layer 61 to expose the transparent conductive layer 50, and the sub-extension 822 is connected to the second semiconductor layer 40 through the second via 83 and the transparent conductive layer 50.

Further, the first extension 72 and the main extension 821 are both disposed at the center of the semiconductor light emitting element, which facilitates uniform injection of current into the first semiconductor layer 20 and the second semiconductor layer 40.

Further, a plurality of sub-expansions 822 are disposed on the main expansion 821 at intervals, and a pitch between adjacent sub-expansions 822 is 30 to 90 μm. If the distance between the sub-expansion parts 822 is too small, the sub-expansion parts 822 are too dense, so that the light absorption area is increased, and the light extraction efficiency is affected; if the sub-spreading portions 822 have an excessively large pitch, current spreading is not uniform, which affects brightness and light emission uniformity. Further, the spacing between adjacent sub-extensions 822 may be the same to facilitate uniform current injection into various regions of the second semiconductor layer 40. In other embodiments, the pitches of the adjacent sub-expansions 822 may also be different, for example, the pitches may gradually increase or decrease from the second pad 81 to the end of the main expansion 821. As a practical matter, the current is usually concentrated at the end of the main expansion portion 821, so that the number of the sub-expansion portions 822 can be properly increased for the end of the main expansion portion 821 to expand the current for improving the current expansion uniformity on the surface of the light emitting element, and further improving the light emitting uniformity and the brightness, as shown in fig. 4.

Further, the sub-extensions 822 may be symmetrically disposed on both sides of the main extension 821 to facilitate uniform current injection into both sides of the main extension 821. Besides, the sub-expansions 822 may also be asymmetrically disposed on two sides of the main expansion 821, for example, the sub-expansions 822 on two sides of the main expansion 821 are alternately distributed at intervals, which can be referred to in fig. 5.

Further, the sub-extensions 822 located on the same side of the main extension 821 may be parallel to each other, which facilitates uniform current injection into the second semiconductor layer 40. In other embodiments, the sub-expansions 822 may not be parallel to each other.

Under the condition of realizing the current homogeneous injection, the width of main extension 821 and sub-extension 822 is reduced as much as possible, so that the light absorption area is reduced, the light emitting area is increased, and the light emitting brightness is improved. Further, the first expansion 72 and the main expansion 821 have the same width. The higher the overlapping area of the first extension portion 72 and the main extension portion 821 is, the more the area of the whole area of the region affected by the light is reduced, and the more the improvement effect of the light emission luminance of the semiconductor light emitting element is.

Further, the length of the sub-extension 822 is 1/4 of the distance from the main extension 821 to the edge of the transparent conductive layer 50, and particularly, the length of the sub-extension 822 may be 20 to 80 μm. Wherein, the lengths of the sub-expansions 822 may be the same or different. When the lengths of the sub-expansions 822 are different, the lengths of the sub-expansions 822 may be regular, for example, the lengths of the sub-expansions 822 gradually decrease or gradually increase from the second pad 81 to the end of the main expansion 821 or are distributed in a long-short period.

Further, the sub-expansion portion 822 and the main expansion portion 821 form an angle A, and the angle A ranges from 30 degrees to 150 degrees. Preferably, the sub-extension 822 is perpendicular to the main extension 821. When the sub-extension 822 is perpendicular to the main extension 821, the best current extension efficiency can be achieved with the shortest line length of the sub-extension 822, and brightness and light emitting uniformity are improved.

The utility model improves the structure of the second expansion part 82, reduces the number of the main expansion parts 821 and the first expansion part 72 in the same area, reduces the shielding and absorption of light, and improves the brightness of the light-emitting element, meanwhile, the sub expansion parts 822 are added on the main expansion part 821 to realize the conduction of current and promote the current to expand to the light-emitting area, and the sub expansion parts 822 are used for dispersing and expanding the current on the main expansion part 821 to ensure that the current is expanded more uniformly, thereby realizing the overall effect of improving brightness and reducing voltage. In addition, the light emitting layer 30 is present in the region where the first and

second expansions

72 and 82 are located, instead of removing the light emitting layer 30 entirely therebetween in the prior art, thereby avoiding luminance loss.

It should be understood that the above-mentioned embodiments are preferred examples of the present invention, and the scope of the present invention is not limited to these examples, and any modification made according to the present invention is within the scope of the present invention.

Claims

1. A semiconductor light emitting element comprising: a substrate; a first semiconductor layer, a light emitting layer, a second semiconductor layer, a transparent conductive layer, and a first insulating layer, and a first electrode and a second electrode, which are sequentially stacked over the substrate,

the first electrode comprises a first bonding pad and a first extension part, wherein the first bonding pad is connected with the first semiconductor layer, the first extension part is formed on the first insulating layer, a first through hole extending to the first semiconductor layer is formed below the first extension part, and the first extension part is connected with the first semiconductor layer through the first through hole;

the second electrode comprises a second bonding pad and a second extension part, wherein the second bonding pad is connected with the second semiconductor layer, the second extension part is formed above the first extension part, a second insulating layer is arranged between the first extension part and the second extension part, the second extension part comprises a main extension part and a sub-extension part connected with the main extension part, the main extension part and the first extension part are located on the same vertical line, a second through hole extending to the transparent conductive layer is arranged below the sub-extension part, and the sub-extension part is connected with the second semiconductor layer through the second through hole and the transparent conductive layer.

2. The semiconductor light-emitting element according to claim 1, wherein the sub-extensions are symmetrically or asymmetrically disposed on both sides of the main extension.

3. The semiconductor light-emitting element according to claim 1, wherein a pitch between adjacent sub-extensions is 30 to 90 μm.

4. The semiconductor light emitting element according to claim 1, wherein the sub-extensions on both sides of the main extension are staggered.

5. The semiconductor light emitting element as claimed in claim 1, wherein the sub-extension portion forms an angle a with the main extension portion, and the angle a is in a range of 30 to 150 degrees.

6. The semiconductor light-emitting element according to claim 1, wherein the sub-extensions located on the same side as the main extension are disposed in parallel or not.

7. The semiconductor light emitting element as claimed in claim 1, wherein the sub-extensions have a length of 20 to 80 μm.

8. The semiconductor light-emitting element according to claim 1, wherein the sub-extensions have the same or different lengths.

9. A semiconductor light emitting element according to claim 1, wherein the length of the sub-extension is gradually decreased or gradually increased or the same from the second pad to the end of the main extension.

10. A semiconductor light emitting element according to claim 1, wherein the pitch between adjacent ones of the sub-extensions is gradually decreased or gradually increased or the same from the second pad toward the end of the main extension.