Optical waveguide type photodetector

Patent metadata

Field	Value
Publication number	US-2021273122-A1
Application number	US-202117188393-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 first semiconductor layer is of a first conductive type. A multiplication layer is of a first conductive type and is provided on the first semiconductor layer. An optical waveguide structure has an end face provided on a first region of the multiplication layer. A photodiode structure has an end face and provided on a second region of the multiplication layer. The photodiode structure has a third semiconductor layer being of a second conductive type, an optical absorption layer being of an intrinsic conductive type or of a second conductive type, and a second semiconductor layer being of a second conductive type which are arranged in this order. The optical waveguide structure includes an optical waveguiding core layer and a cladding layer. The end face of the waveguide type photodiode structure and the end face of the optical waveguide structure are in contact.

First claim

What is claimed is:

1 . An optical waveguide type photodetector comprising:
a first semiconductor layer of a first conductive type; a multiplication layer being of a first conductive type provided on the first semiconductor layer; an optical waveguide structure having an end face and provided on a first region of the multiplication layer and including an optical waveguiding core layer and a cladding layer; and a waveguide type photodiode structure having an end face and provided on a second region of the multiplication layer and having a third semiconductor layer being of a second conductive type, an optical absorption layer being of an intrinsic conductive type or of a second conductive type, and a second semiconductor layer being of a second conductive type which are arranged in this order, wherein the end face of the waveguide type photodiode structure and the end face of the optical waveguide structure are in contact.

2 . The optical waveguide type photodetector according to claim 1 ,
wherein the multiplication layer between the first region of the first semiconductor layer and the optical waveguiding core layer are provided throughout an entire area of the optical waveguide structure.

3 . The optical waveguide type photodetector according to claim 1 further comprising:
a buffer layer provided between the first semiconductor layer and the multiplication layer, the buffer layer being of a first conductive type having a lower impurity concentration than the first semiconductor layer or being an undoped layer, and
a fourth semiconductor layer provided between the buffer layer and the multiplication layer, the fourth semiconductor layer being of a first conductive type having a higher impurity concentration than the multiplication layer.

4 . The optical waveguide type photodetector according to claim 1 ,
wherein the waveguide type photodiode structure further includes a fifth semiconductor layer provided between the third semiconductor layer and the optical absorption layer.

5 . The optical waveguide type photodetector according to claim 4 ,
wherein the fifth semiconductor layer does not extend to a part on the first region of the multiplication layer.

6 . The optical waveguide type photodetector according to claim 1 ,
wherein an angle between the end face of the waveguide type photodiode structure and a plane of the third semiconductor layer is smaller than 90°.

7 . The optical waveguide type photodetector according to claim 1 further comprising:
a first ohmic electrode provided on the first semiconductor layer located outside the waveguide type photodiode structure;
a contact layer of a second conductive type provided on the second semiconductor layer; and
a second ohmic electrode provided on the contact layer.

8 . The optical waveguide type photodetector according to claim 1 further comprising:
a semi-insulating substrate,
wherein the first semiconductor layer is provided on the semi-insulating substrate.

9 . The optical waveguide type photodetector according to claim 1 ,
wherein the first semiconductor layer and the second semiconductor layer are InP layers, wherein the optical absorption layer is an InGaAs layer, wherein the multiplication layer is an InAlAs a layer, and wherein the third semiconductor layer is an InP layer or an InAlGaAs layer.

10 . The optical waveguide type photodetector according to claim 1 ,
wherein the third semiconductor layer is formed on both of the first region and the second region of the multiplication layer.

11 . An optical waveguide type photodetector comprising:
a first semiconductor layer of a first conductive type; an optical waveguide structure having an end face and provided on a first region of the first semiconductor layer and including an optical waveguiding core layer and a cladding layer; a waveguide type photodiode structure having an end face and provided on a second region of the first semiconductor layer and having a multiplication layer being of a first conductive type, a seventh semiconductor layer being of a second conductive type, an optical absorption layer being of an intrinsic conductive type or a second conductive type, and a second semiconductor layer being of a second conductive type which are arranged in this order, and the end face of the waveguide type photodiode structure facing to the end face of the optical waveguide structure; and a sixth semiconductor layer of a second conductive type located between the end face of the optical waveguide structure and the end face of the waveguide type photodiode structure and contacted with the multiplication layer in the end face of the waveguide type photodiode structure.

12 . The optical waveguide type photodetector according to claim 11 ,
wherein the multiplication layer and the seventh semiconductor layer do not extend to a part between the first region of the first semiconductor layer and the optical waveguiding core layer.

13 . The optical waveguide type photodetector according to claim 11 ,
wherein a bandgap of the sixth semiconductor layer is equivalent to a bandgap of the optical waveguiding core layer.

14 . The optical waveguide type photodetector according to claim 11 ,
wherein a thickness of the sixth semiconductor layer is within a range of 0.050 μm to 0.200 μm.

15 . The optical waveguide type photodetector according to claim 11 ,
wherein an impurity concentration of the sixth semiconductor layer is lower than an impurity concentration of the seventh semiconductor layer.

16 . The optical waveguide type photodetector according to claim 11 ,
wherein the first semiconductor layer and the second semiconductor layer are InP layers, wherein the optical absorption layer is an InGaAs layer, wherein the multiplication layer is an InAlAs a layer, wherein the sixth semiconductor layer is an InGaAsP a layer, and wherein the seventh semiconductor layer is an InP layer or an InAlGaAs layer.

Assignees

• Sedi Inc

Inventors

• Yoneda Yoshihiro
• Okimoto Takuya

Classifications

• H10F77/1248

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

• H10F30/222

  the potential barrier being a PN heterojunction · CPC title

• H10F77/147

  Shapes of bodies · 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