Semiconductor photodetector

Patent metadata

Field	Value
Publication number	US-12477839-B2
Application number	US-202318127423-A
Country	US
Kind code	B2
Filing date	Mar 28, 2023
Priority date	Dec 21, 2022
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

A semiconductor photodetector includes a substrate; a mesa structure on the substrate, the mesa structure being composed of some layers including an upper layer and a lower layer, the upper layer being an absorption layer of light, the lower layer being a wide bandgap layer with a bandgap wide enough not to absorb the light; and an insulating film covering a side of the mesa structure, each of the layers comprising single crystals of III-V semiconductors and having a top of a (100) plane, the top of the wide bandgap layer having a shape including a pair of vertices, in [0-11] and [01-1] directions, on a circumference of a minimum bounding circle.

First claim

What is claimed is:

1 . A semiconductor photodetector comprising:
a substrate; a mesa structure on the substrate, the mesa structure comprising layers including an upper layer and a lower layer, the upper layer being an absorption layer of light, the lower layer being a wide bandgap layer with a bandgap wide enough not to absorb the light; and an insulating film covering a side of the mesa structure, each of the layers comprising single crystals of III-V semiconductors and having a top associated with a (100) plane, the top of the wide bandgap layer having a shape including a pair of vertices, in [0-11] and [01-1] directions, on a circumference of a minimum bounding circle.

2 . The semiconductor photodetector according to claim 1 , wherein an angle at each of the pair of vertices is 135 degrees or less.

3 . The semiconductor photodetector according to claim 1 , wherein the top of the wide bandgap layer has a shape including a pair of tips, in [011] and [0-1-1] directions, inside the minimum bounding circle.

4 . The semiconductor photodetector according to claim 3 , wherein the top of the wide bandgap layer has a shape including a pair of arcs convex in the [011] and [0-1-1] directions, respectively.

5 . The semiconductor photodetector according to claim 1 , wherein the top of the wide bandgap layer has a shape including a pair of vertices, in [011] and [0-1-1] directions, on the circumference of the minimum bounding circle.

6 . The semiconductor photodetector according to claim 5 , wherein the top of the wide bandgap layer is polygonal.

7 . The semiconductor photodetector according to claim 1 , wherein the top of a layer above the wide bandgap layer has a shape including a pair of vertices, in the [0-11] and [01-1] directions, on a circumference of a minimum bounding circle.

8 . The semiconductor photodetector according to claim 1 , wherein the top of the wide bandgap layer coincides in shape with a bottom of the absorption layer.

9 . The semiconductor photodetector according to claim 1 , wherein the top of a layer above the wide bandgap layer is circular.

10 . The semiconductor photodetector according to claim 1 , wherein the top of the wide bandgap layer protrudes from the absorption layer.

11 . The semiconductor photodetector according to claim 1 , further comprising an electrode pattern, the electrode pattern including a mesa electrode on a top of the mesa structure.

12 . The semiconductor photodetector according to claim 11 , wherein:
the electrode pattern further includes a connection electrode connected to the mesa electrode, and the connection electrode extends in a [011] direction or a [0-1-1] direction.

13 . The semiconductor photodetector according to claim 11 , wherein the mesa electrode includes an opening in plan view.

14 . The semiconductor photodetector according to claim 13 , wherein the opening is shaped to allow signal light to enter.

15 . The semiconductor photodetector according to claim 14 , wherein the opening is circular.

16 . The semiconductor photodetector according to claim 15 , wherein the mesa electrode is ring-shaped in plan view.

17 . The semiconductor photodetector according to claim 1 , wherein the substrate is shaped to allow signal light to enter from an opposite side to the mesa structure.

18 . The semiconductor photodetector according to claim 1 , wherein the wide bandgap layer is thicker than the absorption layer.

19 . The semiconductor photodetector according to claim 1 , wherein the wide bandgap layer comprises any one of InAlGaAs, InAlAs, and InP.

20 . The semiconductor photodetector according to claim 1 , wherein the absorption layer comprises InGaAs.

Assignees

• Lumentum Operations Llc
• Lumentum Operations

Inventors

• Toyonaka Takashi
• Hamada Hiroshi
• Washino Ryu
• Hamada Shigetaka
• Kato Suguru

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

• H10F77/147

  Shapes of bodies · CPC title

• H10F30/223 Primary

  the potential barrier being a PIN barrier · CPC title