Ultraviolet light receiving device

Patent metadata

Field	Value
Publication number	US-12349473-B2
Application number	US-202117759040-A
Country	US
Kind code	B2
Filing date	Jan 15, 2021
Priority date	Jan 20, 2020
Publication date	Jul 1, 2025
Grant date	Jul 1, 2025

Abstract

Provided is an ultraviolet light receiving device having photosensitivity effective to target wavelengths in the ultraviolet region. A Schottky junction ultraviolet light receiving device has the photosensitivity peak wavelength in an ultraviolet region of 230 nm or more and 320 nm or less, and exhibits a rejection ratio of 10 5 or more, the rejection ratio being the ratio of the responsivity Rp to the peak photosensitivity wavelength to the average of the responsivity Rv to a visible region of 400 nm or more and 680 nm or less (Rp/Rv).

First claim

The invention claimed is:

1. A Schottky ultraviolet light receiving device configured to have a peak photosensitivity wavelength in an ultraviolet region of 230 nm or more and 320 nm or less,
wherein a rejection ratio that is a ratio of a responsivity Rp to the peak photosensitivity wavelength to an average of responsivity Rv to a visible region of 400 nm or more and 680 nm or less (Rp/Rv) is 10 5 or more,
the Schottky ultraviolet light receiving device comprises an AlN layer on a sapphire substrate and an AlGaN laminate made up of a plurality of AlGaN layers having different Al composition ratios on the AlN layer, wherein the AlGaN laminate has an Al w Ga 1-w N buffer layer (0.5≤w≤0.95) and an Al z Ga 1-z N light receiving layer in this order from the AlN layer side;
the values of the Al composition ratios satisfy a relationship of z<w;
the AlGaN laminate has an n-type Al x Ga 1-x N current spreading layer and an n-type Al y Ga 1-y N ohmic contact layer in this order from the AlN layer side between the Al w Ga 1-w N buffer layer and the Al z Ga 1-z N light receiving layer;
the values of the Al composition ratios satisfy a relationship of z≤y<x≤w;
illumination light for measuring the responsivity enters through the sapphire substrate; and
a half width of a photosensitivity spectrum of the ultraviolet light receiving device is 40 nm or less.

2. The ultraviolet light receiving device according to claim 1 ,
wherein the Al z Ga 1-2 N light receiving layer has an etched portion where the n-type Al y Ga 1-y N ohmic contact layer is exposed,
an n-type ohmic electrode is provided on the exposed n-type Al y Ga 1-y N ohmic contact layer, and
a Schottky electrode is placed on the Al z Ga 1-z N light receiving layer.

Assignees

• Dowa Holdings Co Ltd
• Dowa Electronics Materials Co Ltd

Inventors

• Toba Ryuichi
• Watanabe Yasuhiro

Classifications

• H10F77/1248 Primary

  having three or more elements, e.g. GaAlAs, InGaAs or InGaAsP · CPC title

• H10F77/206

  for devices having potential barriers · CPC title

• H10F30/227 Primary

  the potential barrier being a Schottky barrier · CPC title