Semiconductor light-emitting element

Patent metadata

Field	Value
Publication number	US-2020395506-A1
Application number	US-202016895343-A
Country	US
Kind code	A1
Filing date	Jun 8, 2020
Priority date	Jun 11, 2019
Publication date	Dec 17, 2020
Grant date	—

Abstract

A semiconductor light-emitting element is configured to emit ultraviolet light having a wavelength of 320 nm or shorter. Denoting a total area of a principal surface of a substrate as S0, an area on a p-type semiconductor layer in which a p-side contact electrode is formed as S1, an area on an n-type semiconductor layer in which an n-side contact electrode is formed as S2, a reflectivity of the p-side contact electrode for ultraviolet having a wavelength of 280 nm incident from a side of the p-type semiconductor layer as R1, and a reflectivity of the n-side contact electrode for ultraviolet light having a wavelength of 280 nm incident from a side of the n-type semiconductor layer as R2, (S1/S0)×R1+(S2/S0)×R2≥0.5, S1>S2, and R1≤R2.

First claim

What is claimed is:

1 . A semiconductor light-emitting element comprising:
a n-type semiconductor layer made of an n-type AlGaN-based semiconductor material provided on a principal surface of a substrate; an active layer made of an AlGaN-based semiconductor material provided on the n-type semiconductor layer and configured to emit ultraviolet light having a wavelength of 320 nm or shorter; a p-type semiconductor layer provided on the active layer; a p-side contact electrode provided on the p-type semiconductor layer; and an n-side contact electrode provided in a region on the n-type semiconductor layer different from a region in which the active layer is formed, wherein denoting a total area of the principal surface of the substrate as S0, an area on the p-type semiconductor layer in which the p-side contact electrode is formed as S1, an area on the n-type semiconductor layer in which the n-side contact electrode is formed as S2, a reflectivity of the p-side contact electrode for ultraviolet having a wavelength of 280 nm incident from a side of the p-type semiconductor layer as R1, and a reflectivity of the n-side contact electrode for ultraviolet light having a wavelength of 280 nm incident from a side of the n-type semiconductor layer as R2, (S1/S0)×R1+(S2/S0)×R2≥0.5, S1>S2, and R1≤R2.

2 . The semiconductor light-emitting element according to claim 1 , wherein
the p-side contact electrode includes an Rh layer in contact with the p-type semiconductor layer.

3 . The semiconductor light-emitting element according to claim 1 , wherein
the p-side contact electrode includes a transparent conductive oxide layer in contact with the p-type semiconductor layer and a metal layer provided on the transparent conductive oxide layer, and denoting a transmissivity of the transparent conductive oxide layer for ultraviolet having a wavelength of 280 nm incident from a side of the p-type semiconductor layer as T, a reflectivity of the metal layer for ultraviolet having a wavelength of 280 nm incident from a side of the transparent conductive oxide layer as R, the reflectivity R1 of the p-side contact electrode is such that R1=RT 2 .

4 . The semiconductor light-emitting element according to claim 3 , wherein
the transparent conductive oxide layer is an indium tin oxide layer having a thickness of 4 nm or smaller, and the metal layer includes an Al layer having a thickness of 100 nm or larger.

5 . The semiconductor light-emitting element according to claim 1 , wherein
the n-side contact electrode includes a Ti layer in contact with the n-type semiconductor layer and having a thickness of not smaller than 1 nm and not larger than 2 nm and an Al layer provided on the Ti layer and having a thickness of 100 nm or larger.

6 . The semiconductor light-emitting element according to claim 1 , wherein
(S1+S2)/S0≥0.7, R1≥0.6, and R2≥0.8.

7 . The semiconductor light-emitting element according to claim 1 , wherein
the p-type semiconductor layer includes a p-type contact layer in contact with the p-side contact electrode, and the p-type contact layer is a p-type AlGaN or p-type GaN layer having an AlN ratio of 20% or lower, and a contact resistance between the p-type contact layer and the p-side contact electrode is 1×10 −2 Ω·cm 2 or smaller.

8 . The semiconductor light-emitting element according to claim 7 , wherein
a thickness of the p-type contact layer is 20 nm or smaller.

Assignees

• Nikkiso Co Ltd

Inventors

• Inazu Tetsuhiko
• Niwa Noritaka

Classifications

• H10H20/835

  Reflective materials · CPC title

• H10H20/833

  Transparent materials · CPC title

• H10H20/841

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

• H10H20/825 Primary

  containing nitrogen, e.g. GaN · CPC title

• H01L33/405

  Electricity · mapped topic