US-20260130013-A1 - LIGHT-EMITTING DIODE

US20260130013A1US 20260130013 A1US20260130013 A1US 20260130013A1US-20260130013-A1

Abstract

Disclosed is a light-emitting diode including an epitaxial stack, an insulation layer and a connection electrode. The epitaxial stack includes a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence. A trench is provided in the epitaxial stack. The connection electrode includes a first electrode electrically connected to the first semiconductor layer and a second electrode electrically connected to the second semiconductor layer. The first electrode includes a first electrode layer and a second electrode layer formed on the first electrode layer and a surface of the first semiconductor layer exposed by the trench. The first electrode layer includes a first contact layer contacting the insulation layer. The second electrode layer includes a second contact layer contacting the second semiconductor layer. A thickness of the second contact layer is less than a thickness of the first contact layer.

Inventors

Xiushan Zhu
Yan Li
Zhihao Bao
Qi Jing
Chun-Hsien Lee
Juchin TU
CHUNGYING CHANG

Assignees

XIAMEN SAN'AN OPTOELECTRONICS CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251104
Priority Date: 20241104

Claims (18)

1 . A light-emitting diode, comprising: an epitaxial stack, comprising a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, wherein the epitaxial stack has a trench, the trench penetrates the second semiconductor layer, the active layer and a portion of the first semiconductor layer to expose a partial surface of the first semiconductor layer; an insulation layer, formed on the epitaxial stack, wherein the insulation layer is provided with a first through hole and a second through hole; a connection electrode, formed on the insulation layer, and comprising a first electrode and a second electrode, wherein the first electrode is electrically connected to the first semiconductor layer through the second through hole, the second electrode is electrically connected to the second semiconductor layer through the first through hole, the first electrode comprises a first electrode layer formed on the insulation layer and a second electrode layer partially formed on the first electrode layer, a portion of the second electrode layer is in contact with the surface of the first semiconductor layer exposed by the trench through the second through hole, the first electrode layer comprises a first contact layer contacting the insulation layer, the second electrode layer comprises a second contact layer contacting the surface of the first semiconductor layer, wherein a thickness of the second contact layer is less than a thickness of the first contact layer.
2 . The light-emitting diode according to claim 1 , wherein the first contact layer is a metal chromium layer, a metal nickel layer or a metal titanium layer, and the thickness of the first contact layer is 10 Å˜100 Å; the second contact layer is a metal chromium layer, a metal nickel layer or a metal titanium layer, and the thickness of the second contact layer is 3 Å˜25 Å.
3 . The light-emitting diode according to claim 1 , wherein the first electrode layer further comprises a first metal reflective layer formed on the first contact layer, the second electrode layer further comprises a second metal reflective layer formed on the second contact layer, and a thickness of the first metal reflective layer is equal to a thickness of the second metal reflective layer.
4 . The light-emitting diode according to claim 1 , wherein a reflectivity of the first electrode layer is less than a reflectivity of the second electrode layer.
5 . The light-emitting diode according to claim 1 , wherein the second electrode layer has a first portion in contact with the first electrode layer and a second portion in contact with the first semiconductor layer, in a top view of the light-emitting diode along a thickness direction of the epitaxial stack, an area of the first portion is larger than an area of the second portion.
6 . The light-emitting diode according to claim 1 , wherein a plurality of recess portions are further provided at an outer periphery of the epitaxial stack, the recess portions penetrate the second semiconductor layer, the active layer and a portion of the first semiconductor layer along a thickness direction of the epitaxial stack to expose the partial surface of the first semiconductor layer, and the second electrode layer contacts the partial surface of the first semiconductor layer exposed by the recess portions through the second through hole.
7 . The light-emitting diode according to claim 6 , further comprising a substrate, wherein the epitaxial stack is formed on the substrate; in a top view of the light-emitting diode, a distance between the first electrode layer and an edge of the substrate is greater than a distance between the second electrode layer and the edge of the substrate, with a distance between an edge of the first electrode layer and an edge of the second electrode layer being an electrode layer edge spacing, a value of the electrode layer edge spacing in a region where the recess portions are located is greater than a value of the electrode layer edge spacing at other regions of the light-emitting diode.
8 . The light-emitting diode according to claim 1 , wherein the second electrode comprises a third electrode layer and a fourth electrode layer, the third electrode layer comprises a third contact layer formed on the insulation layer, the fourth electrode layer comprises a fourth contact layer formed on the third electrode layer, a thickness of the third contact layer is greater than a thickness of the fourth contact layer.
9 . The light-emitting diode according to claim 8 , wherein a first gap is provided between the first electrode layer and the third electrode layer, a second gap is provided between the second electrode layer and the fourth electrode layer, and a width of the first gap is less than a width of the second gap.
10 . The light-emitting diode according to claim 8 , wherein the third electrode layer further comprises a third metal reflective layer formed on the third contact layer, the fourth electrode layer further comprises a fourth metal reflective layer formed on the fourth contact layer, and a thickness of the third metal reflective layer is equal to a thickness of the fourth metal reflective layer.
11 . The light-emitting diode according to claim 8 , wherein the third contact layer is a metal chromium layer, a metal nickel layer or a metal titanium layer, and the thickness of the third contact layer is 10 Å˜100 Å; the fourth contact layer is a metal chromium layer, a metal nickel layer or a metal titanium layer, and the thickness of the fourth contact layer is 3 Å˜25 Å.
12 . A light-emitting diode, comprising: an epitaxial stack, comprising a first semiconductor layer, an active layer and a second semiconductor layer sequentially stacked, wherein the epitaxial stack has a trench, the trench penetrates the second semiconductor layer, the active layer and a portion of the first semiconductor layer to expose a partial surface of the first semiconductor layer; an insulation layer, formed on the epitaxial stack, wherein the insulation layer is provided a first through hole and a second through hole; a connection electrode, formed on the insulation layer, and comprising a first electrode and a second electrode, wherein the first electrode is electrically connected to the first semiconductor layer through the second through hole, the second electrode is electrically connected to the second semiconductor layer through the first through hole, the first electrode comprises a contact layer, the contact layer comprises a first contact portion formed on the insulation layer and a second contact portion formed on the partial surface of the first semiconductor layer exposed by the trench, and a thickness of the second contact portion is less than a thickness of the first contact portion.
13 . The light-emitting diode according to claim 12 , wherein in a top view of the light-emitting diode, an area of the first contact portion is larger than an area of the second contact portion.
14 . The light-emitting diode according to claim 12 , wherein the light-emitting diode further comprises a transparent conductive layer and a metal layer, the insulation layer comprises a first insulation layer and a second insulation layer; the transparent conductive layer is formed on the epitaxial stack; the second insulation layer is formed on the epitaxial stack, covering the transparent conductive layer, wherein the second insulation layer has a third through hole and a fourth through hole, the third through hole exposes the transparent conductive layer, and the fourth through hole exposes the partial surface of the first semiconductor layer exposed by the trench; the metal layer is formed on the second insulation layer, and in contact with the transparent conductive layer through the third through hole; the first insulation layer is formed on the metal layer and covers the second insulation layer.
15 . The light-emitting diode according to claim 14 , wherein the transparent conductive layer is provided with a plurality of fifth through holes spaced apart from each other, the plurality of fifth through holes expose the second semiconductor layer and are arranged in a staggered manner with the third through hole.
16 . The light-emitting diode according to claim 14 , wherein the light-emitting diode further comprises a metal barrier layer, formed on the second insulation layer and covering the metal layer, the first through hole exposes the metal barrier layer, and the second electrode contacts the metal barrier layer through the first through hole.
17 . The light-emitting diode according to claim 14 , wherein the second insulation layer comprises an insulation barrier layer covering the metal layer, the insulation barrier layer is provided with a sixth through hole, and the second electrode contacts the metal layer through the first through hole and the sixth through hole.
18 . The light-emitting diode according to claim 14 , further comprising: a third insulation layer, located on a side of the first insulation layer away from the second insulation layer, and covering the connection electrode, wherein the third insulation layer is provided with an opening exposing the connection electrode; a pad electrode, located on a side of the connection electrode away from the first insulation layer, and electrically connected to the connection electrode through the opening.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present disclosure claims the priority benefit of China application serial no. 202411558179.2, filed on Nov. 4, 2024. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. BACKGROUND Technical Field The present disclosure relates to the field of semiconductor manufacturing technology, and particularly relates to a light-emitting diode. Description of Related Art Light-emitting diode (LED) is a semiconductor solid-state light-emitting device. With the continuous development of semiconductor technology, the luminous efficiency of light-emitting diodes continues to improve, making light-emitting diodes one of the most valued light sources in recent years. Commercial light-emitting diode packaging initially adopted a forward structure where gold wires connect the chip PN junction to the positive and negative electrodes of the lead frame. However, light-emitting diodes with the forward structure have problems such as large light decay, light quenching, and heat dissipation, which restrict the development of light-emitting diodes with the forward structure. To solve the problem, researchers have successively developed light-emitting diodes with a vertical structure and light-emitting diodes with a flip-chip structure. The flip-chip light-emitting diode may be integrated and produced in bulk, featuring a simple manufacturing process and excellent performance. In flip-chip light-emitting diodes, the PN junction is bonded to the positive and negative electrodes on the substrate through eutectic bonding without the use of gold wire, thus addressing the issue of light quenching. The heat generated by the light emission may be directly conducted to the heat sink without passing through the substrate, thereby enhancing heat dissipation. Furthermore, the interconnection between the chip and the substrate shortens the electrical path, accelerates the signal transmission speed, reduces the response delay, and improves the overall performance. However, in flip-chip light-emitting diodes, to achieve connection between the metal electrode and the light-emitting structure, through holes exposing the bottom N-type semiconductor layer are formed in the light-emitting structure, and the metal electrode is electrically connected to the N-type semiconductor layer via the through holes. Since the metal layer and reflective layer of the light-emitting diode cannot cover the through holes, this inevitably leads to reduced light extraction efficiency of the light-emitting diode during use, thereby affecting the luminous effect of the light-emitting diode. SUMMARY Given the problems in the related art described above, the purpose of the present disclosure is to provide a light-emitting diode and a light-emitting device for improving the light extraction efficiency of the light-emitting diode and enhancing the luminous effect. To achieve the above purpose and other related purposes, an aspect of the present disclosure provides a light-emitting diode, including: An epitaxial stack, including a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, wherein the epitaxial stack has a trench, the trench penetrates the second semiconductor layer, the active layer and a portion of the first semiconductor layer to expose a partial surface of the first semiconductor layer; An insulation layer, formed on the epitaxial stack, wherein the insulation layer is provided with a first through hole and a second through hole; A connection electrode, formed on the insulation layer, and including a first electrode and a second electrode, wherein the first electrode is electrically connected to the first semiconductor layer through the second through hole, the second electrode is electrically connected to the second semiconductor layer through the first through hole, the first electrode includes a first electrode layer formed on the insulation layer and a second electrode layer partially formed on the first electrode layer, the second electrode layer also includes a portion contacting the surface of the first semiconductor layer exposed by the trench through the second through hole, the first electrode layer includes a first contact layer contacting the insulation layer, the second electrode layer includes a second contact layer contacting the surface of the first semiconductor layer; wherein a thickness of the second contact layer is less than a thickness of the first contact layer. Another aspect of the present disclosure also provides a light-emitting diode, including: An epitaxial stack, including a first semiconductor layer, an active layer and a second semiconductor layer stacked in sequence, wherein the epitaxial stack has a trench, the trench penetrates the second semiconductor layer, the active layer and a portion of the first semiconductor layer to expose a partial surface of the firs