Optoelectronic device

Patent metadata

Field	Value
Publication number	US-10133094-B1
Application number	US-201715700053-A
Country	US
Kind code	B1
Filing date	Sep 8, 2017
Priority date	Jul 5, 2017
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

An optoelectronic device and method of making the same. The device comprising: a substrate; a regrown cladding layer, on top of the substrate; and an optically active region, above the regrown cladding layer; wherein the regrown cladding layer has a refractive index which is less than a refractive index of the optically active region, such that an optical mode of the optoelectronic device is confined to the optically active region.

First claim

The invention claimed is:

1. An optoelectronic device, comprising:
a substrate;
a regrown cladding layer, on the substrate;
an insulating layer;
an optically active region, above the regrown cladding layer;
a first waveguide; and
a second waveguide,
wherein:
the regrown cladding layer has a refractive index which is less than a refractive index of the optically active region, such that an optical mode of the optoelectronic device is confined to the optically active region,
the insulating layer is directly on the substrate, over a first region of the substrate,
the regrown cladding layer is on the substrate, over a second region of the substrate, different from the first region of the substrate,
the first waveguide is on the insulating layer,
the second waveguide is in the optically active region,
the substrate is a silicon substrate,
the insulating layer is an oxide layer,
the first waveguide is over the first region of the substrate and extends to a boundary between the first region of the substrate and the second region of the substrate,
the second waveguide is over the second region of the substrate and extends to the boundary between the first region of the substrate and the second region of the substrate,
the first waveguide is configured to support a first optical mode, and
the second waveguide is configured to support a second optical mode, coupled to the first optical mode.

2. The optoelectronic device of claim 1 , wherein the optically active region is an electro-absorption modulator or a photodiode.

3. The optoelectronic device of either claim 1 , wherein the optically active region is formed of Si x Ge 1-x-y Sn y where 5%≤x≤20%, 1%≤y≤10%.

4. The optoelectronic device of claim 1 , wherein the cladding layer is formed of silicon or SiGe and is epitaxially grown silicon or SiGe.

5. The optoelectronic device of claim 1 , further comprising a silicon seed layer between the cladding layer and the optically active region.

6. The optoelectronic device of claim 1 , wherein the optically active region comprises a silicon-germanium region.

7. The optoelectronic device of claim 1 , wherein a length of the optically active region is between 30 μm and 60 μm.

8. The optoelectronic device of claim 1 , further comprising:
an insulating layer, disposed on a first and/or second horizontal side of the cladding layer, wherein the cladding layer has a height from the substrate substantially equal to or greater than that of the insulating layer.

9. The optoelectronic device of claim 1 , wherein the optically active region is disposed within a cavity of a silicon-on-insulator layer which is disposed above the substrate.

10. The optoelectronic device of claim 1 , further comprising:
an input waveguide, coupled to a first side of the optically active region; and
an output waveguide, coupled to a second side of the optically active region;
wherein the interface between the input waveguide and the optically active region and the interface between the output waveguide and the optically active region are at an angle greater than 0° relative to a guiding direction of the input waveguide and/or output waveguide.

11. The optoelectronic device of claim 1 , wherein the optically active region includes a waveguide ridge, and has:
an upper surface and a lower surface;
a lower doped region, located at and/or adjacent to at least a portion of the lower surface of the optically active region, and extends laterally outwards from the waveguide ridge in a first direction;
an upper doped region, located at and/or adjacent to at least a portion of the upper surface of the waveguide ridge of the optically active region, and extends laterally outwards from the waveguide ridge in a second direction; and
an intrinsic region located between the lower doped region and the upper doped region.

12. The optoelectronic device of claim 1 , wherein the optically active region includes a rib waveguide modulation region, the rib waveguide modulation region having:
a ridge extending from the cladding layer;
a first slab region at a first side of the ridge and a second slab region at a second side of the ridge; and
wherein:
a first doped region extends along: the first slab region and along a first sidewall of the ridge, the first sidewall contacting the first slab region; and
a second doped region extends along: the second slab region and along a second sidewall of the ridge, the second sidewall contacting the second slab region.

13. The optoelectronic device of claim 1 , wherein the optically active region includes a rib waveguide modulation region, the rib waveguide modulation region having:
a ridge extending from the cladding layer, at least a portion of the ridge being formed from a chosen semiconductor material which is different from the material of the cladding layer;
wherein the cladding layer includes a first slab region at a first side of the ridge and a second slab region at a second side of the ridge; and
wherein:
a first doped region extends along: the first slab region and along a first sidewall of the ridge, the first sidewall contacting the first slab region; and
a second doped region extends along: the second slab region and along a second sidewall of the ridge, the second sidewall contacting the second slab region.

14. The optoelectronic device of claim 1 , wherein the optically active region includes a rib waveguide modulation region, the rib waveguide modulation region having:
a ridge extending from the cladding layer, at least a portion of the ridge being formed from a chosen semiconductor material which is different from the material of the cladding layer;
a first slab region at a first side of the ridge and a second slab region at a second side of the ridge; and either the first slab region or the second slab region is the material of the cladding layer; and
wherein:
a first doped region extends along: the first slab region and along a first sidewall of the ridge, the first sidewall contacting the first slab region; and
a second doped region extends along: the second slab region and along a second sidewall of the ridge, the second sidewall contacting the second slab region.

15. The optoelectronic device of claim 1 , wherein the optically active region includes a rib waveguide modulation region, the rib waveguide modulation region having:
a silicon base, disposed on top of the cladding layer;
a ridge extending from the silicon base, at least a portion of the ridge being formed from a chosen semiconductor material which is different from the material of the silicon base;
wherein the silicon base includes a first slab region at a first side of the ridge, and a second slab region at a second side of the ridge; and
wherein:
a first doped region extends along: the first slab region and along a first sidewall of the ridge, the first sidewall contacting the first slab region; and
a second doped region extends along: the second slab region and along a second sidewall of the ridge, the second sidewall contacting the second slab region.

16. The optoelectronic device of claim 1 , wherein the optically active region includes:
a waveguide ridge; and
a waveguide slab;
wherein at least one of: a sidewall of the ridge; a portion of the slab; the entirety of the slab; a portion of the ridge adjacent to the slab; and both sidewalls of the ridge; are formed of crystalline or amorphous silicon and contain dopants.

17. The optoelectronic device of claim 16 , wherein the remainder of the waveguide ridge and waveguide slab is formed of SiGe, g

Assignees

• Rockley Photonics Ltd

Inventors

• Yu Guomin
• Abediasl Hooman
• Lerose Damiana
• Nagra Amit Singh
• Srinivasan Pradeep
• Jones Haydn Frederick

Classifications

• H10P54/00

  Cutting or separating of wafers, substrates or parts of devices · CPC title

• G01J5/024 Primary

  Special manufacturing steps or sacrificial layers or layer structures · CPC title

• G02F1/025 Primary

  in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) · CPC title

• G02F1/2257

  the optical waveguides being made of semiconducting material · CPC title

• G02B6/136

  by etching · CPC title