Semiconductor optical device and semiconductor assembly

Patent metadata

Field	Value
Publication number	US-9696496-B2
Application number	US-201615341316-A
Country	US
Kind code	B2
Filing date	Nov 2, 2016
Priority date	Nov 5, 2015
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A semiconductor optical device includes a semiconductor substrate having first to fourth regions, a 90-degree optical hybrid provided in the third region on a principal surface of the semiconductor substrate, first and second waveguides provided in the first region and being optically coupled to the 90-degree optical hybrid, a photodiode provided in the fourth region, a third waveguide provided in the second region to optically couple the 90-degree optical hybrid to the photodiode, and a metal layer provided on a back surface of the semiconductor substrate. The metal layer includes a first part provided in the first region and a second part provided in the second region that is spaced apart from the first part by a distance. The 90-degree optical hybrid has a first length. The distance between the first and second parts is more than or equal to the first length.

First claim

What is claimed is:

1. A semiconductor optical device comprising:
a semiconductor substrate having a first side edge and a second side edge extending in a direction of a first axis and including a first region, a second region, a third region, and a fourth region;
a 90-degree optical hybrid provided in the third region on a principal surface of the semiconductor substrate;
a first waveguide optically coupled to a first port of the 90-degree optical hybrid and provided in the first region on the principal surface of the semiconductor substrate;
a second waveguide optically coupled to a second port of the 90-degree optical hybrid and provided in the first region on the principal surface of the semiconductor substrate;
a photodiode provided in the fourth region on the principal surface of the semiconductor substrate;
a third waveguide provided in the second region on the principal surface of the semiconductor substrate to optically couple a third port of the 90-degree optical hybrid to the photodiode; and
a metal layer provided on a back surface of the semiconductor substrate and including a first part and a second part spaced from each other by a distance,
wherein the first region, the third region, the second region, and the fourth region are arranged in this order in the direction of the first axis,
wherein the first part of the metal layer is provided in the first region on the back surface of the semiconductor substrate,
wherein the second part of the metal layer is provided in the second region on the back surface of the semiconductor substrate,
wherein the 90-degree optical hybrid has a first length defined in the direction of the first axis on the principal surface of the semiconductor substrate,
wherein the third region of the semiconductor substrate extends from the first side edge to the second side edge of the semiconductor substrate in a direction of a second axis intersecting the first axis, and the third region of the semiconductor substrate has a length defined in the direction of the first axis equal to the first length, and
wherein the distance between the first part and the second part is more than or equal to the first length.

2. The semiconductor optical device according to claim 1 , wherein the first part of the metal layer has a portion extending from the first side edge to the second side edge of the semiconductor substrate in the direction of the second axis.

3. The semiconductor optical device according to claim 1 , wherein the second part of the metal layer has a portion extending from the first side edge to the second side edge of the semiconductor substrate in the direction of the second axis.

4. The semiconductor optical device according to claim 1 , wherein the 90-degree optical hybrid includes a first multi-mode interferometer and a second multi-mode interferometer, the first multi-mode interferometer is connected to the first waveguide and the second waveguide, the second multi-mode interferometer is connected to the third waveguide, and the first multi-mode interferometer and the second multi-mode interferometer are provided in the third region.

5. The semiconductor optical device according to claim 4 ,
wherein the 90-degree optical hybrid further includes a fourth waveguide provided in the third region to optically couple the first multi-mode interferometer and the second multi-mode interferometer, and the first multi-mode interferometer, the fourth waveguide, and the second multi-mode interferometer are arranged in order in the direction of the first axis, and
wherein the metal layer further includes a third part spaced from the first part and the second part and provided on a back surface of the fourth waveguide, and the third part is located between the first part and the second part on the back surface of the semiconductor substrate.

6. The semiconductor optical device according to claim 5 , wherein the third part of the metal layer has a portion extending from the first side edge to the second side edge of the semiconductor substrate in the direction of the second axis.

7. The semiconductor optical device according to claim 1 ,
wherein the first part of the metal layer has a first opening extending in the direction of the first axis, and
wherein the back surface of the semiconductor substrate is exposed in the opening.

8. The semiconductor optical device according to claim 7 ,
wherein the second part of the metal layer has a second opening extending in the direction of the first axis,
wherein the back surface of the semiconductor substrate is exposed in the openings,
wherein the 90-degree optical hybrid has a first width defined in the direction of the second axis on the principal surface of the semiconductor substrate, and
each of the first opening and the second opening has a width larger than the first width.

9. A semiconductor assembly comprising:
a semiconductor optical device including a semiconductor substrate having first to fourth regions, a 90-degree optical hybrid provided in the third region on a principal surface of the semiconductor substrate, first and second waveguides provided in the first region on the principal surface of the semiconductor substrate and optically coupled to the 90-degree optical hybrid, a photodiode provided in the fourth region on the principal surface of the semiconductor substrate, a third waveguide provided in the second region on the principal surface of the semiconductor substrate to optically couple a port of the 90-degree optical hybrid to the photodiode, and a metal layer provided on a back surface of the semiconductor substrate and including a first part and a second part spaced from each other by a distance larger than a length of the 90-degree optical hybrid;
a mount substrate having a mount surface and a metal film provided on the mount surface; and
a bonding member that bonds the semiconductor optical device to the metal film of the mount substrate.

Assignees

• Sumitomo Electric Industries

Inventors

• Masuyama Ryuji
• Yoneda Yoshihiro
• Yagi Hideki
• Sakurai Kenji
• Kikuchi Takehiko

Classifications

• H01L31/03046

  Electricity · mapped topic

• H01L31/1844

  Electricity · mapped topic

• H01L31/02005

  Electricity · mapped topic

• G02B6/29344 Primary

  operating by modal interference or beating, i.e. of transverse modes, e.g. zero-gap directional coupler, MMI · CPC title

• H01L31/02327

  Electricity · mapped topic