Semiconductor light receiving element

Patent metadata

Field	Value
Publication number	US-2021273121-A1
Application number	US-202117188335-A
Country	US
Kind code	A1
Filing date	Mar 1, 2021
Priority date	Mar 2, 2020
Publication date	Sep 2, 2021
Grant date	—

Abstract

A semiconductor light receiving element includes a first semiconductor layer, a waveguide type photodiode structure, an optical waveguide structure, and a fourth semiconductor layer. The waveguide type photodiode structure is provided on the first semiconductor layer. The waveguide type photodiode structure includes an optical absorption layer, a second semiconductor layer, a multiplication layer, and a third semiconductor layer. The optical waveguide structure is provided on the first semiconductor layer. The optical waveguide structure includes an optical waveguiding core layer and a cladding layer. An end face of the waveguide type photodiode structure faces to an end face of the optical waveguide structure. The fourth semiconductor layer is located between the end face of the waveguide type photodiode structure and the end face of the optical waveguide structure. The fourth semiconductor layer is contacted with the multiplication layer of the end face of the waveguide type photodiode structure.

First claim

What is claimed is:

1 . A semiconductor light receiving element comprising:
a first semiconductor layer of a first conductive type; a waveguide type photodiode structure having an end face provided on the first semiconductor layer and including an optical absorption layer being of an intrinsic conductive type or a first conductive type, a second semiconductor layer being of a first conductive type, a multiplication layer being of an intrinsic conductive type or a first conductive type, and a third semiconductor layer being of a second conductive type; an optical waveguide structure having an end face provided on the first semiconductor layer and including an optical waveguiding core layer and a cladding layer, the end face of the waveguide type photodiode structure facing to the end face of the optical waveguide structure; and a fourth semiconductor layer being of a second conductive type located between the end face of the waveguide type photodiode structure and the end face of the optical waveguide structure and contacted with the multiplication layer of the end face of the waveguide type photodiode structure.

2 . The semiconductor light receiving element according to claim 1 ,
wherein an impurity concentration of the fourth semiconductor layer is lower than an impurity concentration of the third semiconductor layer.

3 . The semiconductor light receiving element according to claim 1 further comprising:
a fifth semiconductor layer provided between the first semiconductor layer and the optical absorption layer,
wherein the fifth semiconductor layer is of a first conductive type having a lower impurity concentration than the first semiconductor layer and extends between the first semiconductor layer and the optical waveguiding core layer.

4 . The semiconductor light receiving element according to claim 1 ,
wherein the waveguide type photodiode structure further includes a sixth semiconductor layer provided between the first semiconductor layer and the optical absorption layer and being of a first conductive type having a lower impurity concentration than the first semiconductor layer.

5 . The semiconductor light receiving element according to claim 1 further comprising:
a semiconductor passivation film provided in the waveguide type photodiode structure,
wherein in the waveguide type photodiode structure, the optical absorption layer, the second semiconductor layer, the multiplication layer, and the third semiconductor layer constitute a stripe mesa structure extending in a first direction that is an arrangement direction of the waveguide type photodiode structure and the optical waveguide structure,
wherein the stripe mesa structure has a pair of side surfaces extending in the first direction, and
wherein the semiconductor passivation film comes into contact with the pair of side surfaces.

6 . The semiconductor light receiving element according to claim 1 ,
wherein an impurity concentration of the fourth semiconductor layer is 3×10 16 cm −3 or lower.

7 . The semiconductor light receiving element according to claim 1 ,
wherein a bandgap of the fourth semiconductor layer is larger than a bandgap of the optical absorption layer and is equivalent to a bandgap of the first semiconductor layer or smaller than the bandgap of the first semiconductor layer.

8 . The semiconductor light receiving element according to claim 1 ,
wherein an angle between the end face of the waveguide type photodiode structure and a plane of the first semiconductor layer is smaller than 90°.

9 . The semiconductor light receiving element according to claim 1 further comprising:
a contact layer of a second conductive type provided on the third semiconductor layer;
a first ohmic electrode provided on the contact layer; and
a second ohmic electrode provided on the first semiconductor layer located outside the waveguide type photodiode structure.

10 . The semiconductor light receiving element according to claim 1 further comprising:
a semi-insulating substrate,
wherein the first semiconductor layer is provided on the semi-insulating substrate.

11 . The semiconductor light receiving element according to claim 1 ,
wherein a bandgap of the fourth semiconductor layer is equivalent to a bandgap of the optical waveguiding core layer.

12 . The semiconductor light receiving element according to claim 1 ,
wherein the first semiconductor layer, the multiplication layer, and the third semiconductor layer are InP layers, wherein the optical absorption layer is an InGaAs layer, wherein the second semiconductor layer is an InP layer or an InAlGaAs layer, and wherein the fourth semiconductor layer is an InGaAsP layer.

13 . The semiconductor light receiving element according to claim 1 ,
wherein a thickness of the fourth semiconductor layer is within a range of 0.050 μm to 0.200 μm.

14 . A semiconductor light receiving element comprising:
a first semiconductor layer of a first conductive type; a photodiode structure provided on the first semiconductor layer, the photodiode structure having an end face, the photodiode structure including an optical absorption layer being of an intrinsic conductive type or a first conductive type, a second semiconductor layer being of a first conductive type, a multiplication layer being of an intrinsic conductive type or a first conductive type, and a third semiconductor layer being of a second conductive type; and a seventh semiconductor layer being of a second conductive type and contacted with the multiplication layer on the end face of the photodiode structure.

15 . The semiconductor light receiving element according to claim 14 ,
wherein an impurity concentration of the seventh semiconductor layer is lower than an impurity concentration of the third semiconductor layer.

16 . The semiconductor light receiving element according to claim 14 ,
wherein an impurity concentration of the seventh semiconductor layer is 3×10 16 cm −3 or lower.

17 . The semiconductor light receiving element according to claim 14 ,
wherein a bandgap of the seventh semiconductor layer is larger than a bandgap of the optical absorption layer and is equivalent to a bandgap of the first semiconductor layer or smaller than the bandgap of the first semiconductor layer.

Assignees

• Sedi Inc

Inventors

• Yoneda Yoshihiro
• Ebihara Koji
• Okimoto Takuya

Classifications

• H10F77/1248

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

• H10F77/147

  Shapes of bodies · CPC title

• H10F30/222

  the potential barrier being a PN heterojunction · CPC title

• H10F39/103

  the at least one element covered by H10F30/00 having potential barriers, e.g. integrated devices comprising photodiodes or phototransistors · CPC title

• H10F77/14

  Shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies · CPC title