Light emitting device and method for manufacturing light emitting device

Patent metadata

Field	Value
Publication number	US-2025098372-A1
Application number	US-202418790756-A
Country	US
Kind code	A1
Filing date	Jul 31, 2024
Priority date	Sep 15, 2023
Publication date	Mar 20, 2025
Grant date	—

Abstract

The present disclosure provides a light emitting device in which the ultraviolet reflectance can be improved while the p-side electrode can form ohmic contact with the p-type layer. A flip-chip type ultraviolet light emitting device includes an n-type layer, an active layer, a p-type layer, a p-side electrode formed on the p-type layer, including a layer in contact with the p-type layer and made of Ru, Rh, or an alloy containing those metals as a main component, and having a thickness that transmits ultraviolet light with an emission wavelength, an insulating DBR layer formed on and in contact with a part of the p-side electrode, and reflecting ultraviolet light with an emission wavelength, a second p-side electrode being electrically connected with the p-side electrode through a hole formed in a region on the p-side electrode of the DBR layer.

First claim

1 . A flip-chip type ultraviolet light emitting device comprising:
an n-type layer made of n-type group III nitride semiconductor; an active layer formed on the n-type layer and made of group III nitride semiconductor, a p-type layer formed on the active layer and made of p-type group III nitride semiconductor; a p-side electrode formed on the p-type layer, including a layer made of Ru, Rh, or an alloy containing those metals as a main component and formed in contact with the p-type layer, and having a thickness that transmits ultraviolet light with an emission wavelength; an insulating DBR layer formed on and in contact with a part of the p-side electrode, and reflecting ultraviolet light with an emission wavelength; and a second p-side electrode being electrically connected with the p-side electrode through a hole formed in a region on the p-side electrode of the DBR layer.

2 . The light emitting device according to claim 1 , wherein the DBR layer is formed on and in contact with a part of the p-side electrode, and in contact with at least one side of the n-type layer, the active layer, and the p-type layer.

3 . The light emitting device according to claim 1 , wherein the emission wavelength is 200 nm to 280 nm.

4 . The light emitting device according to claim 1 , wherein the DBR layer contains HfO 2 .

5 . The light emitting device according to claim 1 , wherein the thickness of the p-side electrode is 1 nm to 50 nm.

6 . The light emitting device according to claim 1 , wherein
the p-type layer includes a p-type contact layer in contact with the p-side electrode and made of GaN, and the thickness of the p-type contact layer is 1 nm to 50 nm.

7 . The light emitting device according to claim 1 , wherein
the p-type layer includes a p-type contact layer in contact with the p-side electrode and made of AlGaN having an Al composition of 50% or less, and the thickness of the p-type contact layer is 20 nm or less.

8 . A method for manufacturing a flip-chip type ultraviolet light emitting device, the method comprising:
forming an n-type layer made of n-type group III nitride semiconductor; forming an active layer made of group III nitride semiconductor on the n-type layer; forming a p-type layer made of p-type group III nitride semiconductor on the active layer; forming a p-side electrode on the p-type layer, the p-side electrode including a layer made of Ru, Rh, or an alloy containing those metals as a main component and formed in contact with the p-type layer, and having a thickness that transmits ultraviolet light with an emission wavelength; forming an insulating DBR layer on and in contact with a part of the p-side electrode, the DBR layer reflecting ultraviolet light with an emission wavelength; and forming a second p-side electrode to be electrically connected with the p-side electrode through a hole formed in a region on the p-side electrode of the DBR layer.

Assignees

• Toyoda Gosei Kk

Inventors

• Mizutani Koichi
• Omoya Hideki
• Matsui Shinichi
• Makino Hiroaki

Classifications

• H10H20/841

  Reflective coatings, e.g. dielectric Bragg reflectors · CPC title

• H10H20/032

  of electrodes · CPC title

• H10H20/833 Primary

  Transparent materials · CPC title

• H10H20/0137

  the light-emitting regions comprising nitride materials · CPC title

• H10H20/825

  containing nitrogen, e.g. GaN · CPC title