Light-emitting diode and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-11862752-B2
Application number	US-202117366268-A
Country	US
Kind code	B2
Filing date	Jul 2, 2021
Priority date	Mar 1, 2019
Publication date	Jan 2, 2024
Grant date	Jan 2, 2024

Abstract

A light-emitting diode includes a substrate, a distributed Bragg reflector (DBR) structure and a semiconductor layered structure. The DBR structure is disposed on the substrate. The semiconductor layered structure is disposed on the DBR structure opposite to the substrate, and is configured to emit a light having a first wavelength. The DBR structure has a reflectance of not greater than 30% for the light having the first wavelength, and a reflectance of not smaller than 50% for a laser beam having a second wavelength that is different from the first wavelength.

First claim

What is claimed is:

1. A light-emitting diode (LED), comprising:
a substrate which has an upper surface, a lower surface that is opposite to said upper surface, and a side surface connecting said upper surface and said lower surface;
a distributed Bragg reflector (DBR) structure which is disposed on said upper surface of said substrate; and
a semiconductor layered structure which is disposed on said DBR structure opposite to said substrate, and which is configured to emit a light having a first wavelength;
wherein said DBR structure has a reflectance of not greater than 30% for the light having the first wavelength, and a reflectance of not smaller than 50% for a laser beam having a second wavelength that is different from the first wavelength.

2. The LED of claim 1 , wherein the first wavelength ranges from 400 nm to 800 nm.

3. The LED of claim 1 , wherein the laser beam having the second wavelength is used for a dicing process.

4. The LED of claim 1 , wherein the second wavelength is one of 365±35 nm and 1064±100 nm.

5. The LED of claim 1 , wherein said DBR structure includes a first layered unit which includes a plurality of pairs of layers, said layers in each pair including a first high refractive index layer and a first low refractive index layer, said first high refractive index layers and said first low refractive index layers in said first layered unit being alternately stacked.

6. The LED of claim 5 , wherein said DBR structure further includes a second layered unit disposed on said first layered unit opposite to said substrate, said second layered unit including a plurality of pairs of layers, said layers in each pair including a second high refractive index layer and a second low refractive index layer, said second high refractive index layers and said second low refractive index layers in said second layered unit being alternately stacked, and wherein for said second layered unit, each of said second high refractive index layers having an optical thickness different from that of each of said first high refractive index layers, and each of said second low refractive index layers having an optical thickness different from that of each of said first low refractive index layers.

7. The LED of claim 5 , wherein each of said first high refractive index layers is made of a material selected from the group consisting of TiO 2 , Nb 2 O 5 , Ta 2 O 5 , HfO 2 , ZrO 2 , ZnO, LaTiO 3 , and combinations thereof, and each of said first low refractive index layers is made of a material selected from the group consisting of SiO 2 , MgF 2 , Al 2 O 5 , SiON, and combinations thereof.

8. The LED of claim 6 , wherein each of said second high refractive index layers is made of a material selected from the group consisting of TiO 2 , Nb 2 O 5 , Ta 2 O 5 , HfO 2 , ZrO 2 , ZnO, LaTiO 3 , and combinations thereof, and each of said second low refractive index layers is made of a material selected from the group consisting of SiO 2 , MgF 2 , Al 2 O 5 , SiON, and combinations thereof.

9. The LED of claim 6 , wherein each of said first high refractive index layers and said first low refractive index layers has an optical thickness of (¼)×k 1 ×λ 1 , wherein 1000 nm<λ 1 <1200 nm, and k 1 is an odd number.

10. The LED of claim 6 , wherein each of said second high refractive index layers and said second low refractive index layers has an optical thickness of (¼)×k 2 ×λ 2 , wherein 350 nm<λ 2 <380 nm, and k 2 is an odd number.

11. The LED of claim 6 , wherein said first layered unit includes n pairs of layers, and n≥3.

12. The LED of claim 6 , wherein said second layered unit includes m pairs of layers, and n≥2.

13. The LED of claim 1 , further comprising a buffer layer which is made of an AlN-based material, and which is disposed between said semiconductor layered structure and said DBR structure.

14. The LED of claim 1 , wherein said semiconductor layered structure is tapered inwardly toward said DBR structure.

15. The LED of claim 1 , wherein said side surface of said substrate has multiple inscribed features of stealth dicing.

16. The LED of claim 15 , wherein one of the inscribed features that is most adjacent to said upper surface being spaced apart therefrom by a distance less than 20 μm.

17. A method of producing an LED, comprising the steps of:
(a) providing a substrate which has an upper surface, a lower surface that is opposite to the upper surface, and a side surface interconnecting the upper surface and the lower surface;
(b) forming a DBR structure on the upper surface of the substrate; and
(c) forming a semiconductor layered structure on the DBR structure opposite to the substrate, the semiconductor layered structure being configured to emit a light having a first wavelength;
wherein the DBR structure has a reflectance of not greater than 30% for the light having the first wavelength, and a reflectance of not smaller than 50% for a laser beam having a second wavelength which is different from the first wavelength.

18. The method of claim 17 , further comprising at least one of the steps of:
(d) performing laser scribing on the semiconductor layered structure using a first laser beam; and
(e) performing stealth dicing from the lower surface of the substrate using a second laser beam different from the first laser beam;
wherein the reflectance of the DBR structure to each of the first and second laser beams is not smaller than 50%.

19. The method of claim 18 , wherein the second wavelength of the first laser beam is 365±35 nm, and the second wavelength of the second laser beam is 1064±100 nm.

20. The method of claim 17 , further comprising, before step (c), a step of forming a buffer layer made of an AlN-based material on the DBR structure opposite to the substrate, and in step (c), the semiconductor layered structure being formed on the buffer layer opposite to the DBR structure.

Assignees

• Xiamen Sanan Optoelectronics Technology Co Ltd
• Quanzhou Sanan Semiconductor Tech Co Ltd

Inventors

• Wang Qing
• Chen Dazhong
• Hsu Sheng-Hsien
• Hong ling-yuan
• Peng Kang-Wei
• Lin Su-Hui
• Chang Chia-Hung

Classifications

• H10H20/0363

  of optical field-shaping means · CPC title

• H10H20/821

  of the light-emitting regions, e.g. non-planar junctions · CPC title

• H10H20/815

  having stress relaxation structures, e.g. buffer layers · CPC title

• H10H20/01 Primary

  Manufacture or treatment · CPC title

• H10H20/814 Primary

  having reflecting means, e.g. semiconductor Bragg reflectors · CPC title